Adding upstream version 2.4.56.upstream/2.4.56

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

65 files changed, 25931 insertions, 0 deletions

diff --git a/modules/md/Makefile.in b/modules/md/Makefile.in
new file mode 100644
index 0000000..4395bc3
--- /dev/null
+++ b/modules/md/Makefile.in
@@ -0,0 +1,20 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#
+#   standard stuff
+#
+
+include $(top_srcdir)/build/special.mk
diff --git a/modules/md/config2.m4 b/modules/md/config2.m4
new file mode 100644
index 0000000..11d4f32
--- /dev/null
+++ b/modules/md/config2.m4
@@ -0,0 +1,311 @@
+dnl Licensed to the Apache Software Foundation (ASF) under one or more
+dnl contributor license agreements.  See the NOTICE file distributed with
+dnl this work for additional information regarding copyright ownership.
+dnl The ASF licenses this file to You under the Apache License, Version 2.0
+dnl (the "License"); you may not use this file except in compliance with
+dnl the License.  You may obtain a copy of the License at
+dnl
+dnl      http://www.apache.org/licenses/LICENSE-2.0
+dnl
+dnl Unless required by applicable law or agreed to in writing, software
+dnl distributed under the License is distributed on an "AS IS" BASIS,
+dnl WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+dnl See the License for the specific language governing permissions and
+dnl limitations under the License.
+
+dnl
+dnl APACHE_CHECK_CURL
+dnl
+dnl Configure for libcurl, giving preference to
+dnl "--with-curl=<path>" if it was specified.
+dnl
+AC_DEFUN([APACHE_CHECK_CURL],[
+  AC_CACHE_CHECK([for curl], [ac_cv_curl], [
+    dnl initialise the variables we use
+    ac_cv_curl=no
+    ap_curl_found=""
+    ap_curl_base=""
+    ap_curl_libs=""
+
+    dnl Determine the curl base directory, if any
+    AC_MSG_CHECKING([for user-provided curl base directory])
+    AC_ARG_WITH(curl, APACHE_HELP_STRING(--with-curl=PATH, curl installation directory), [
+      dnl If --with-curl specifies a directory, we use that directory
+      if test "x$withval" != "xyes" -a "x$withval" != "x"; then
+        dnl This ensures $withval is actually a directory and that it is absolute
+        ap_curl_base="`cd $withval ; pwd`"
+      fi
+    ])
+    if test "x$ap_curl_base" = "x"; then
+      AC_MSG_RESULT(none)
+    else
+      AC_MSG_RESULT($ap_curl_base)
+    fi
+
+    dnl Run header and version checks
+    saved_CPPFLAGS="$CPPFLAGS"
+    saved_LIBS="$LIBS"
+    saved_LDFLAGS="$LDFLAGS"
+
+    dnl Before doing anything else, load in pkg-config variables
+    if test -n "$PKGCONFIG"; then
+      saved_PKG_CONFIG_PATH="$PKG_CONFIG_PATH"
+      AC_MSG_CHECKING([for pkg-config along $PKG_CONFIG_PATH])
+      if test "x$ap_curl_base" != "x" ; then
+        if test -f "${ap_curl_base}/lib/pkgconfig/libcurl.pc"; then
+          dnl Ensure that the given path is used by pkg-config too, otherwise
+          dnl the system libcurl.pc might be picked up instead.
+          PKG_CONFIG_PATH="${ap_curl_base}/lib/pkgconfig${PKG_CONFIG_PATH+:}${PKG_CONFIG_PATH}"
+          export PKG_CONFIG_PATH
+        elif test -f "${ap_curl_base}/lib64/pkgconfig/libcurl.pc"; then
+          dnl Ensure that the given path is used by pkg-config too, otherwise
+          dnl the system libcurl.pc might be picked up instead.
+          PKG_CONFIG_PATH="${ap_curl_base}/lib64/pkgconfig${PKG_CONFIG_PATH+:}${PKG_CONFIG_PATH}"
+          export PKG_CONFIG_PATH
+        fi
+      fi
+      AC_ARG_ENABLE(curl-staticlib-deps,APACHE_HELP_STRING(--enable-curl-staticlib-deps,[link mod_md with dependencies of libcurl's static libraries (as indicated by "pkg-config --static"). Must be specified in addition to --enable-md.]), [
+        if test "$enableval" = "yes"; then
+          PKGCONFIG_LIBOPTS="--static"
+        fi
+      ])
+      ap_curl_libs="`$PKGCONFIG $PKGCONFIG_LIBOPTS --libs-only-l --silence-errors libcurl`"
+      if test $? -eq 0; then
+        ap_curl_found="yes"
+        pkglookup="`$PKGCONFIG --cflags-only-I libcurl`"
+        APR_ADDTO(CPPFLAGS, [$pkglookup])
+        APR_ADDTO(MOD_CFLAGS, [$pkglookup])
+        pkglookup="`$PKGCONFIG $PKGCONFIG_LIBOPTS --libs-only-L libcurl`"
+        APR_ADDTO(LDFLAGS, [$pkglookup])
+        APR_ADDTO(MOD_LDFLAGS, [$pkglookup])
+        pkglookup="`$PKGCONFIG $PKGCONFIG_LIBOPTS --libs-only-other libcurl`"
+        APR_ADDTO(LDFLAGS, [$pkglookup])
+        APR_ADDTO(MOD_LDFLAGS, [$pkglookup])
+      fi
+      PKG_CONFIG_PATH="$saved_PKG_CONFIG_PATH"
+    fi
+
+    dnl fall back to the user-supplied directory if not found via pkg-config
+    if test "x$ap_curl_base" != "x" -a "x$ap_curl_found" = "x"; then
+      APR_ADDTO(CPPFLAGS, [-I$ap_curl_base/include])
+      APR_ADDTO(MOD_CFLAGS, [-I$ap_curl_base/include])
+      APR_ADDTO(LDFLAGS, [-L$ap_curl_base/lib])
+      APR_ADDTO(MOD_LDFLAGS, [-L$ap_curl_base/lib])
+      if test "x$ap_platform_runtime_link_flag" != "x"; then
+        APR_ADDTO(LDFLAGS, [$ap_platform_runtime_link_flag$ap_curl_base/lib])
+        APR_ADDTO(MOD_LDFLAGS, [$ap_platform_runtime_link_flag$ap_curl_base/lib])
+      fi
+    fi
+
+    AC_CHECK_HEADERS([curl/curl.h])
+
+    AC_MSG_CHECKING([for curl version >= 7.29])
+    AC_TRY_COMPILE([#include <curl/curlver.h>],[
+#if !defined(LIBCURL_VERSION_MAJOR)
+#error "Missing libcurl version"
+#endif
+#if LIBCURL_VERSION_MAJOR < 7
+#error "Unsupported libcurl version " LIBCURL_VERSION
+#endif
+#if LIBCURL_VERSION_MAJOR == 7 && LIBCURL_VERSION_MINOR < 29
+#error "Unsupported libcurl version " LIBCURL_VERSION
+#endif],
+      [AC_MSG_RESULT(OK)
+       ac_cv_curl=yes],
+      [AC_MSG_RESULT(FAILED)])
+
+    if test "x$ac_cv_curl" = "xyes"; then
+      ap_curl_libs="${ap_curl_libs:--lcurl} `$apr_config --libs`"
+      APR_ADDTO(MOD_LDFLAGS, [$ap_curl_libs])
+      APR_ADDTO(LIBS, [$ap_curl_libs])
+    fi
+
+    dnl restore
+    CPPFLAGS="$saved_CPPFLAGS"
+    LIBS="$saved_LIBS"
+    LDFLAGS="$saved_LDFLAGS"
+  ])
+  if test "x$ac_cv_curl" = "xyes"; then
+    AC_DEFINE(HAVE_CURL, 1, [Define if curl is available])
+  fi
+])
+
+
+dnl
+dnl APACHE_CHECK_JANSSON
+dnl
+dnl Configure for libjansson, giving preference to
+dnl "--with-jansson=<path>" if it was specified.
+dnl
+AC_DEFUN([APACHE_CHECK_JANSSON],[
+  AC_CACHE_CHECK([for jansson], [ac_cv_jansson], [
+    dnl initialise the variables we use
+    ac_cv_jansson=no
+    ap_jansson_found=""
+    ap_jansson_base=""
+    ap_jansson_libs=""
+
+    dnl Determine the jansson base directory, if any
+    AC_MSG_CHECKING([for user-provided jansson base directory])
+    AC_ARG_WITH(jansson, APACHE_HELP_STRING(--with-jansson=PATH, jansson installation directory), [
+      dnl If --with-jansson specifies a directory, we use that directory
+      if test "x$withval" != "xyes" -a "x$withval" != "x"; then
+        dnl This ensures $withval is actually a directory and that it is absolute
+        ap_jansson_base="`cd $withval ; pwd`"
+      fi
+    ])
+    if test "x$ap_jansson_base" = "x"; then
+      AC_MSG_RESULT(none)
+    else
+      AC_MSG_RESULT($ap_jansson_base)
+    fi
+
+    dnl Run header and version checks
+    saved_CPPFLAGS="$CPPFLAGS"
+    saved_LIBS="$LIBS"
+    saved_LDFLAGS="$LDFLAGS"
+
+    dnl Before doing anything else, load in pkg-config variables
+    if test -n "$PKGCONFIG"; then
+      saved_PKG_CONFIG_PATH="$PKG_CONFIG_PATH"
+      AC_MSG_CHECKING([for pkg-config along $PKG_CONFIG_PATH])
+      if test "x$ap_jansson_base" != "x" ; then
+        if test -f "${ap_jansson_base}/lib/pkgconfig/libjansson.pc"; then
+          dnl Ensure that the given path is used by pkg-config too, otherwise
+          dnl the system libjansson.pc might be picked up instead.
+          PKG_CONFIG_PATH="${ap_jansson_base}/lib/pkgconfig${PKG_CONFIG_PATH+:}${PKG_CONFIG_PATH}"
+          export PKG_CONFIG_PATH
+        elif test -f "${ap_jansson_base}/lib64/pkgconfig/libjansson.pc"; then
+          dnl Ensure that the given path is used by pkg-config too, otherwise
+          dnl the system libjansson.pc might be picked up instead.
+          PKG_CONFIG_PATH="${ap_jansson_base}/lib64/pkgconfig${PKG_CONFIG_PATH+:}${PKG_CONFIG_PATH}"
+          export PKG_CONFIG_PATH
+        fi
+      fi
+      AC_ARG_ENABLE(jansson-staticlib-deps,APACHE_HELP_STRING(--enable-jansson-staticlib-deps,[link mod_md with dependencies of libjansson's static libraries (as indicated by "pkg-config --static"). Must be specified in addition to --enable-md.]), [
+        if test "$enableval" = "yes"; then
+          PKGCONFIG_LIBOPTS="--static"
+        fi
+      ])
+      ap_jansson_libs="`$PKGCONFIG $PKGCONFIG_LIBOPTS --libs-only-l --silence-errors libjansson`"
+      if test $? -eq 0; then
+        ap_jansson_found="yes"
+        pkglookup="`$PKGCONFIG --cflags-only-I libjansson`"
+        APR_ADDTO(CPPFLAGS, [$pkglookup])
+        APR_ADDTO(MOD_CFLAGS, [$pkglookup])
+        pkglookup="`$PKGCONFIG $PKGCONFIG_LIBOPTS --libs-only-L libjansson`"
+        APR_ADDTO(LDFLAGS, [$pkglookup])
+        APR_ADDTO(MOD_LDFLAGS, [$pkglookup])
+        pkglookup="`$PKGCONFIG $PKGCONFIG_LIBOPTS --libs-only-other libjansson`"
+        APR_ADDTO(LDFLAGS, [$pkglookup])
+        APR_ADDTO(MOD_LDFLAGS, [$pkglookup])
+      fi
+      PKG_CONFIG_PATH="$saved_PKG_CONFIG_PATH"
+    fi
+
+    dnl fall back to the user-supplied directory if not found via pkg-config
+    if test "x$ap_jansson_base" != "x" -a "x$ap_jansson_found" = "x"; then
+      APR_ADDTO(CPPFLAGS, [-I$ap_jansson_base/include])
+      APR_ADDTO(MOD_CFLAGS, [-I$ap_jansson_base/include])
+      APR_ADDTO(LDFLAGS, [-L$ap_jansson_base/lib])
+      APR_ADDTO(MOD_LDFLAGS, [-L$ap_jansson_base/lib])
+      if test "x$ap_platform_runtime_link_flag" != "x"; then
+        APR_ADDTO(LDFLAGS, [$ap_platform_runtime_link_flag$ap_jansson_base/lib])
+        APR_ADDTO(MOD_LDFLAGS, [$ap_platform_runtime_link_flag$ap_jansson_base/lib])
+      fi
+    fi
+
+    # attempts to include jansson.h fail me. So lets make sure we can at least
+    # include its other header file
+    AC_TRY_COMPILE([#include <jansson_config.h>],[],
+      [AC_MSG_RESULT(OK) 
+       ac_cv_jansson=yes], 
+       [AC_MSG_RESULT(FAILED)])
+
+    if test "x$ac_cv_jansson" = "xyes"; then
+      ap_jansson_libs="${ap_jansson_libs:--ljansson} `$apr_config --libs`"
+      APR_ADDTO(MOD_LDFLAGS, [$ap_jansson_libs])
+      APR_ADDTO(LIBS, [$ap_jansson_libs])
+    fi
+
+    dnl restore
+    CPPFLAGS="$saved_CPPFLAGS"
+    LIBS="$saved_LIBS"
+    LDFLAGS="$saved_LDFLAGS"
+  ])
+  if test "x$ac_cv_jansson" = "xyes"; then
+    AC_DEFINE(HAVE_JANSSON, 1, [Define if jansson is available])
+  fi
+])
+
+
+dnl #  start of module specific part
+APACHE_MODPATH_INIT(md)
+
+dnl #  list of module object files
+md_objs="dnl
+md_acme.lo dnl
+md_acme_acct.lo dnl
+md_acme_authz.lo dnl
+md_acme_drive.lo dnl
+md_acmev2_drive.lo dnl
+md_acme_order.lo dnl
+md_core.lo dnl
+md_curl.lo dnl
+md_crypt.lo dnl
+md_event.lo dnl
+md_http.lo dnl
+md_json.lo dnl
+md_jws.lo dnl
+md_log.lo dnl
+md_ocsp.lo dnl
+md_result.lo dnl
+md_reg.lo dnl
+md_status.lo dnl
+md_store.lo dnl
+md_store_fs.lo dnl
+md_tailscale.lo dnl
+md_time.lo dnl
+md_util.lo dnl
+mod_md.lo dnl
+mod_md_config.lo dnl
+mod_md_drive.lo dnl
+mod_md_ocsp.lo dnl
+mod_md_os.lo dnl
+mod_md_status.lo dnl
+"
+
+# Ensure that other modules can pick up mod_md.h
+APR_ADDTO(INCLUDES, [-I\$(top_srcdir)/$modpath_current])
+
+dnl # hook module into the Autoconf mechanism (--enable-md)
+APACHE_MODULE(md, [Managed Domain handling], $md_objs, , most, [
+    APACHE_CHECK_OPENSSL
+    if test "x$ac_cv_openssl" = "xno" ; then
+        AC_MSG_WARN([libssl (or compatible) not found])
+        enable_md=no
+    fi
+    
+    APACHE_CHECK_JANSSON
+    if test "x$ac_cv_jansson" != "xyes" ; then
+        AC_MSG_WARN([libjansson not found])
+        enable_md=no
+    fi
+
+    APACHE_CHECK_CURL
+    if test "x$ac_cv_curl" != "xyes" ; then
+        AC_MSG_WARN([libcurl not found])
+        enable_md=no
+    fi
+    
+    AC_CHECK_FUNCS([arc4random_buf], 
+        [APR_ADDTO(MOD_CPPFLAGS, ["-DMD_HAVE_ARC4RANDOM"])], [])
+
+    if test "x$enable_md" = "xshared"; then
+       APR_ADDTO(MOD_MD_LDADD, [-export-symbols-regex md_module])
+    fi
+])
+
+dnl #  end of module specific part
+APACHE_MODPATH_FINISH
+
diff --git a/modules/md/md.h b/modules/md/md.h
new file mode 100644
index 0000000..1d75d10
--- /dev/null
+++ b/modules/md/md.h
@@ -0,0 +1,330 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_h
+#define mod_md_md_h
+
+#include <apr_time.h>
+
+#include "md_time.h"
+#include "md_version.h"
+
+struct apr_array_header_t;
+struct apr_hash_t;
+struct md_json_t;
+struct md_cert_t;
+struct md_job_t;
+struct md_pkey_t;
+struct md_result_t;
+struct md_store_t;
+struct md_srv_conf_t;
+struct md_pkey_spec_t;
+
+#define MD_PKEY_RSA_BITS_MIN       2048
+#define MD_PKEY_RSA_BITS_DEF       2048
+
+/* Minimum age for the HSTS header (RFC 6797), considered appropriate by Mozilla Security */
+#define MD_HSTS_HEADER             "Strict-Transport-Security"
+#define MD_HSTS_MAX_AGE_DEFAULT    15768000
+
+#define PROTO_ACME_TLS_1        "acme-tls/1"
+
+#define MD_TIME_LIFE_NORM           (apr_time_from_sec(100 * MD_SECS_PER_DAY))
+#define MD_TIME_RENEW_WINDOW_DEF    (apr_time_from_sec(33 * MD_SECS_PER_DAY))
+#define MD_TIME_WARN_WINDOW_DEF     (apr_time_from_sec(10 * MD_SECS_PER_DAY))
+#define MD_TIME_OCSP_KEEP_NORM      (apr_time_from_sec(7 * MD_SECS_PER_DAY))
+
+#define MD_OTHER                "other"
+
+typedef enum {
+    MD_S_UNKNOWN = 0,               /* MD has not been analysed yet */
+    MD_S_INCOMPLETE = 1,            /* MD is missing necessary information, cannot go live */
+    MD_S_COMPLETE = 2,              /* MD has all necessary information, can go live */
+    MD_S_EXPIRED_DEPRECATED = 3,    /* deprecated */
+    MD_S_ERROR = 4,                 /* MD data is flawed, unable to be processed as is */ 
+    MD_S_MISSING_INFORMATION = 5,     /* User has not agreed to ToS */
+} md_state_t;
+
+typedef enum {
+    MD_REQUIRE_UNSET = -1,
+    MD_REQUIRE_OFF,
+    MD_REQUIRE_TEMPORARY,
+    MD_REQUIRE_PERMANENT,
+} md_require_t;
+
+typedef enum {
+    MD_RENEW_DEFAULT = -1,          /* default value */
+    MD_RENEW_MANUAL,                /* manually triggered renewal of certificate */
+    MD_RENEW_AUTO,                  /* automatic process performed by httpd */
+    MD_RENEW_ALWAYS,                /* always renewed by httpd, even if not necessary */
+} md_renew_mode_t;
+
+typedef struct md_t md_t;
+struct md_t {
+    const char *name;               /* unique name of this MD */
+    struct apr_array_header_t *domains; /* all DNS names this MD includes */
+    struct apr_array_header_t *contacts;   /* list of contact uris, e.g. mailto:xxx */
+
+    int transitive;                 /* != 0 iff VirtualHost names/aliases are auto-added */
+    md_require_t require_https;     /* Iff https: is required for this MD */
+    
+    int renew_mode;                 /* mode of obtaining credentials */
+    struct md_pkeys_spec_t *pks;    /* specification for generating private keys */
+    int must_staple;                /* certificates should set the OCSP Must Staple extension */
+    md_timeslice_t *renew_window;   /* time before expiration that starts renewal */
+    md_timeslice_t *warn_window;    /* time before expiration that warnings are sent out */
+    
+    const char *ca_proto;           /* protocol used vs CA (e.g. ACME) */
+    struct apr_array_header_t *ca_urls; /* urls of CAs */
+    const char *ca_effective;       /* url of CA used */
+    const char *ca_account;         /* account used at CA */
+    const char *ca_agreement;       /* accepted agreement uri between CA and user */
+    struct apr_array_header_t *ca_challenges; /* challenge types configured for this MD */
+    struct apr_array_header_t *cert_files; /* != NULL iff pubcerts explicitly configured */
+    struct apr_array_header_t *pkey_files; /* != NULL iff privkeys explicitly configured */
+    const char *ca_eab_kid;         /* optional KEYID for external account binding */
+    const char *ca_eab_hmac;        /* optional HMAC for external account binding */
+
+    md_state_t state;               /* state of this MD */
+    const char *state_descr;        /* description of state of NULL */
+    
+    struct apr_array_header_t *acme_tls_1_domains; /* domains supporting "acme-tls/1" protocol */
+    int stapling;                   /* if OCSP stapling is enabled */
+    const char *dns01_cmd;          /* DNS challenge command, override global command */
+
+    int watched;               /* if certificate is supervised (renew or expiration warning) */
+    const struct md_srv_conf_t *sc; /* server config where it was defined or NULL */
+    const char *defn_name;          /* config file this MD was defined */
+    unsigned defn_line_number;      /* line number of definition */
+    
+    const char *configured_name;    /* name this MD was configured with, if different */
+};
+
+#define MD_KEY_ACCOUNT          "account"
+#define MD_KEY_ACME_TLS_1       "acme-tls/1"
+#define MD_KEY_ACTIVATION_DELAY "activation-delay"
+#define MD_KEY_ACTIVITY         "activity"
+#define MD_KEY_AGREEMENT        "agreement"
+#define MD_KEY_AUTHORIZATIONS   "authorizations"
+#define MD_KEY_BITS             "bits"
+#define MD_KEY_CA               "ca"
+#define MD_KEY_CA_URL           "ca-url"
+#define MD_KEY_CERT             "cert"
+#define MD_KEY_CERT_FILES       "cert-files"
+#define MD_KEY_CERTIFICATE      "certificate"
+#define MD_KEY_CHALLENGE        "challenge"
+#define MD_KEY_CHALLENGES       "challenges"
+#define MD_KEY_CMD_DNS01        "cmd-dns-01"
+#define MD_KEY_COMPLETE         "complete"
+#define MD_KEY_CONTACT          "contact"
+#define MD_KEY_CONTACTS         "contacts"
+#define MD_KEY_CSR              "csr"
+#define MD_KEY_CURVE            "curve"
+#define MD_KEY_DETAIL           "detail"
+#define MD_KEY_DISABLED         "disabled"
+#define MD_KEY_DIR              "dir"
+#define MD_KEY_DOMAIN           "domain"
+#define MD_KEY_DOMAINS          "domains"
+#define MD_KEY_EAB              "eab"
+#define MD_KEY_EAB_REQUIRED     "externalAccountRequired"
+#define MD_KEY_ENTRIES          "entries"
+#define MD_KEY_ERRORED          "errored"
+#define MD_KEY_ERROR            "error"
+#define MD_KEY_ERRORS           "errors"
+#define MD_KEY_EXPIRES          "expires"
+#define MD_KEY_FINALIZE         "finalize"
+#define MD_KEY_FINISHED         "finished"
+#define MD_KEY_FROM             "from"
+#define MD_KEY_GOOD             "good"
+#define MD_KEY_HMAC             "hmac"
+#define MD_KEY_HTTP             "http"
+#define MD_KEY_HTTPS            "https"
+#define MD_KEY_ID               "id"
+#define MD_KEY_IDENTIFIER       "identifier"
+#define MD_KEY_KEY              "key"
+#define MD_KEY_KID              "kid"
+#define MD_KEY_KEYAUTHZ         "keyAuthorization"
+#define MD_KEY_LAST             "last"
+#define MD_KEY_LAST_RUN         "last-run"
+#define MD_KEY_LOCATION         "location"
+#define MD_KEY_LOG              "log"
+#define MD_KEY_MDS              "managed-domains"
+#define MD_KEY_MESSAGE          "message"
+#define MD_KEY_MUST_STAPLE      "must-staple"
+#define MD_KEY_NAME             "name"
+#define MD_KEY_NEXT_RUN         "next-run"
+#define MD_KEY_NOTIFIED         "notified"
+#define MD_KEY_NOTIFIED_RENEWED "notified-renewed"
+#define MD_KEY_OCSP             "ocsp"
+#define MD_KEY_OCSPS            "ocsps"
+#define MD_KEY_ORDERS           "orders"
+#define MD_KEY_PERMANENT        "permanent"
+#define MD_KEY_PKEY             "privkey"
+#define MD_KEY_PKEY_FILES       "pkey-files"
+#define MD_KEY_PROBLEM          "problem"
+#define MD_KEY_PROTO            "proto"
+#define MD_KEY_READY            "ready"
+#define MD_KEY_REGISTRATION     "registration"
+#define MD_KEY_RENEW            "renew"
+#define MD_KEY_RENEW_AT         "renew-at"
+#define MD_KEY_RENEW_MODE       "renew-mode"
+#define MD_KEY_RENEWAL          "renewal"
+#define MD_KEY_RENEWING         "renewing"
+#define MD_KEY_RENEW_WINDOW     "renew-window"
+#define MD_KEY_REQUIRE_HTTPS    "require-https"
+#define MD_KEY_RESOURCE         "resource"
+#define MD_KEY_RESPONSE         "response"
+#define MD_KEY_REVOKED          "revoked"
+#define MD_KEY_SERIAL           "serial"
+#define MD_KEY_SHA256_FINGERPRINT  "sha256-fingerprint"
+#define MD_KEY_STAPLING         "stapling"
+#define MD_KEY_STATE            "state"
+#define MD_KEY_STATE_DESCR      "state-descr"
+#define MD_KEY_STATUS           "status"
+#define MD_KEY_STORE            "store"
+#define MD_KEY_SUBPROBLEMS      "subproblems"
+#define MD_KEY_TEMPORARY        "temporary"
+#define MD_KEY_TOS              "termsOfService"
+#define MD_KEY_TOKEN            "token"
+#define MD_KEY_TOTAL            "total"
+#define MD_KEY_TRANSITIVE       "transitive"
+#define MD_KEY_TYPE             "type"
+#define MD_KEY_UNKNOWN          "unknown"
+#define MD_KEY_UNTIL            "until"
+#define MD_KEY_URL              "url"
+#define MD_KEY_URLS             "urls"
+#define MD_KEY_URI              "uri"
+#define MD_KEY_VALID            "valid"
+#define MD_KEY_VALID_FROM       "valid-from"
+#define MD_KEY_VALUE            "value"
+#define MD_KEY_VERSION          "version"
+#define MD_KEY_WATCHED          "watched"
+#define MD_KEY_WHEN             "when"
+#define MD_KEY_WARN_WINDOW      "warn-window"
+
+/* Check if a string member of a new MD (n) has 
+ * a value and if it differs from the old MD o
+ */
+#define MD_VAL_UPDATE(n,o,s)    ((n)->s != (o)->s)
+#define MD_SVAL_UPDATE(n,o,s)   ((n)->s && (!(o)->s || strcmp((n)->s, (o)->s)))
+
+/**
+ * Determine if the Managed Domain contains a specific domain name.
+ */
+int md_contains(const md_t *md, const char *domain, int case_sensitive);
+
+/**
+ * Determine if the names of the two managed domains overlap.
+ */
+int md_domains_overlap(const md_t *md1, const md_t *md2);
+
+/**
+ * Determine if the domain names are equal.
+ */
+int md_equal_domains(const md_t *md1, const md_t *md2, int case_sensitive);
+
+/**
+ * Determine if the domains in md1 contain all domains of md2.
+ */
+int md_contains_domains(const md_t *md1, const md_t *md2);
+
+/**
+ * Get one common domain name of the two managed domains or NULL.
+ */
+const char *md_common_name(const md_t *md1, const md_t *md2);
+
+/**
+ * Get the number of common domains.
+ */
+apr_size_t md_common_name_count(const md_t *md1, const md_t *md2);
+
+/**
+ * Look up a managed domain by its name.
+ */
+md_t *md_get_by_name(struct apr_array_header_t *mds, const char *name);
+
+/**
+ * Look up a managed domain by a DNS name it contains.
+ */
+md_t *md_get_by_domain(struct apr_array_header_t *mds, const char *domain);
+
+/**
+ * Find a managed domain, different from the given one, that has overlaps
+ * in the domain list.
+ */
+md_t *md_get_by_dns_overlap(struct apr_array_header_t *mds, const md_t *md);
+
+/**
+ * Create and empty md record, structures initialized.
+ */
+md_t *md_create_empty(apr_pool_t *p);
+
+/**
+ * Create a managed domain, given a list of domain names.
+ */
+md_t *md_create(apr_pool_t *p, struct apr_array_header_t *domains);
+
+/**
+ * Deep copy an md record into another pool.
+ */
+md_t *md_clone(apr_pool_t *p, const md_t *src);
+
+/**
+ * Shallow copy an md record into another pool.
+ */
+md_t *md_copy(apr_pool_t *p, const md_t *src);
+
+/** 
+ * Convert the managed domain into a JSON representation and vice versa. 
+ *
+ * This reads and writes the following information: name, domains, ca_url, ca_proto and state.
+ */
+struct md_json_t *md_to_json(const md_t *md, apr_pool_t *p);
+md_t *md_from_json(struct md_json_t *json, apr_pool_t *p);
+
+/**
+ * Same as md_to_json(), but with sensitive fields stripped.
+ */
+struct md_json_t *md_to_public_json(const md_t *md, apr_pool_t *p);
+
+int md_is_covered_by_alt_names(const md_t *md, const struct apr_array_header_t* alt_names);
+
+/* how many certificates this domain has/will eventually have. */
+int md_cert_count(const md_t *md);
+
+const char *md_get_ca_name_from_url(apr_pool_t *p, const char *url);
+apr_status_t md_get_ca_url_from_name(const char **purl, apr_pool_t *p, const char *name);
+
+/**************************************************************************************************/
+/* notifications */
+
+typedef apr_status_t md_job_notify_cb(struct md_job_t *job, const char *reason, 
+                                      struct md_result_t *result, apr_pool_t *p, void *baton);
+
+/**************************************************************************************************/
+/* domain credentials */
+
+typedef struct md_pubcert_t md_pubcert_t;
+struct md_pubcert_t {
+    struct apr_array_header_t *certs;     /* chain of const md_cert*, leaf cert first */
+    struct apr_array_header_t *alt_names; /* alt-names of leaf cert */
+    const char *cert_file;                /* file path of chain */
+    const char *key_file;                 /* file path of key for leaf cert */
+};
+
+#define MD_OK(c)                    (APR_SUCCESS == (rv = c))
+
+#endif /* mod_md_md_h */
diff --git a/modules/md/md_acme.c b/modules/md/md_acme.c
new file mode 100644
index 0000000..4366bf6
--- /dev/null
+++ b/modules/md/md_acme.c
@@ -0,0 +1,797 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_buckets.h>
+#include <apr_hash.h>
+#include <apr_uri.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_jws.h"
+#include "md_http.h"
+#include "md_log.h"
+#include "md_store.h"
+#include "md_result.h"
+#include "md_util.h"
+#include "md_version.h"
+
+#include "md_acme.h"
+#include "md_acme_acct.h"
+
+
+static const char *base_product= "-";
+
+typedef struct acme_problem_status_t acme_problem_status_t;
+
+struct acme_problem_status_t {
+    const char *type; /* the ACME error string */
+    apr_status_t rv;  /* what Apache status code we give it */
+    int input_related; /* if error indicates wrong input value */
+};
+
+static acme_problem_status_t Problems[] = {
+    { "acme:error:badCSR",                       APR_EINVAL,   1 },
+    { "acme:error:badNonce",                     APR_EAGAIN,   0 },
+    { "acme:error:badSignatureAlgorithm",        APR_EINVAL,   1 },
+    { "acme:error:externalAccountRequired",      APR_EINVAL,   1 },
+    { "acme:error:invalidContact",               APR_BADARG,   1 },
+    { "acme:error:unsupportedContact",           APR_EGENERAL, 1 },
+    { "acme:error:malformed",                    APR_EINVAL,   1 },
+    { "acme:error:rateLimited",                  APR_BADARG,   0 },
+    { "acme:error:rejectedIdentifier",           APR_BADARG,   1 },
+    { "acme:error:serverInternal",               APR_EGENERAL, 0 },
+    { "acme:error:unauthorized",                 APR_EACCES,   0 },
+    { "acme:error:unsupportedIdentifier",        APR_BADARG,   1 },
+    { "acme:error:userActionRequired",           APR_EAGAIN,   0 },
+    { "acme:error:badRevocationReason",          APR_EINVAL,   1 },
+    { "acme:error:caa",                          APR_EGENERAL, 0 },
+    { "acme:error:dns",                          APR_EGENERAL, 0 },
+    { "acme:error:connection",                   APR_EGENERAL, 0 },
+    { "acme:error:tls",                          APR_EGENERAL, 0 },
+    { "acme:error:incorrectResponse",            APR_EGENERAL, 0 },
+};
+
+static apr_status_t problem_status_get(const char *type) {
+    size_t i;
+
+    if (strstr(type, "urn:ietf:params:") == type) {
+        type += strlen("urn:ietf:params:");
+    }
+    else if (strstr(type, "urn:") == type) {
+        type += strlen("urn:");
+    }
+     
+    for(i = 0; i < (sizeof(Problems)/sizeof(Problems[0])); ++i) {
+        if (!apr_strnatcasecmp(type, Problems[i].type)) {
+            return Problems[i].rv;
+        }
+    }
+    return APR_EGENERAL;
+}
+
+int md_acme_problem_is_input_related(const char *problem) {
+    size_t i;
+
+    if (!problem) return 0;
+    if (strstr(problem, "urn:ietf:params:") == problem) {
+        problem += strlen("urn:ietf:params:");
+    }
+    else if (strstr(problem, "urn:") == problem) {
+        problem += strlen("urn:");
+    }
+
+    for(i = 0; i < (sizeof(Problems)/sizeof(Problems[0])); ++i) {
+        if (!apr_strnatcasecmp(problem, Problems[i].type)) {
+            return Problems[i].input_related;
+        }
+    }
+    return 0;
+}
+
+/**************************************************************************************************/
+/* acme requests */
+
+static void req_update_nonce(md_acme_t *acme, apr_table_t *hdrs)
+{
+    if (hdrs) {
+        const char *nonce = apr_table_get(hdrs, "Replay-Nonce");
+        if (nonce) {
+            acme->nonce = apr_pstrdup(acme->p, nonce);
+        }
+    }
+}
+
+static apr_status_t http_update_nonce(const md_http_response_t *res, void *data)
+{
+    req_update_nonce(data, res->headers);
+    return APR_SUCCESS;
+}
+
+static md_acme_req_t *md_acme_req_create(md_acme_t *acme, const char *method, const char *url)
+{
+    apr_pool_t *pool;
+    md_acme_req_t *req;
+    apr_status_t rv;
+    
+    rv = apr_pool_create(&pool, acme->p);
+    if (rv != APR_SUCCESS) {
+        return NULL;
+    }
+    apr_pool_tag(pool, "md_acme_req");
+    
+    req = apr_pcalloc(pool, sizeof(*req));
+    if (!req) {
+        apr_pool_destroy(pool);
+        return NULL;
+    }
+        
+    req->acme = acme;
+    req->p = pool;
+    req->method = method;
+    req->url = url;
+    req->prot_fields = md_json_create(pool);
+    req->max_retries = acme->max_retries;
+    req->result = md_result_make(req->p, APR_SUCCESS);
+    return req;
+}
+ 
+static apr_status_t acmev2_new_nonce(md_acme_t *acme)
+{
+    return md_http_HEAD_perform(acme->http, acme->api.v2.new_nonce, NULL, http_update_nonce, acme);
+}
+
+
+apr_status_t md_acme_init(apr_pool_t *p, const char *base,  int init_ssl)
+{
+    base_product = base;
+    return init_ssl? md_crypt_init(p) : APR_SUCCESS;
+}
+
+static apr_status_t inspect_problem(md_acme_req_t *req, const md_http_response_t *res)
+{
+    const char *ctype;
+    md_json_t *problem = NULL;
+    apr_status_t rv;
+
+    ctype = apr_table_get(req->resp_hdrs, "content-type");
+    ctype = md_util_parse_ct(res->req->pool, ctype);
+    if (ctype && !strcmp(ctype, "application/problem+json")) {
+        /* RFC 7807 */
+        rv = md_json_read_http(&problem, req->p, res);
+        if (rv == APR_SUCCESS && problem) {
+            const char *ptype, *pdetail;
+            
+            req->resp_json = problem;
+            ptype = md_json_gets(problem, MD_KEY_TYPE, NULL); 
+            pdetail = md_json_gets(problem, MD_KEY_DETAIL, NULL);
+            req->rv = problem_status_get(ptype);
+            md_result_problem_set(req->result, req->rv, ptype, pdetail,
+                                  md_json_getj(problem, MD_KEY_SUBPROBLEMS, NULL));
+            
+            
+            
+            if (APR_STATUS_IS_EAGAIN(req->rv)) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, req->rv, req->p,
+                              "acme reports %s: %s", ptype, pdetail);
+            }
+            else {
+                md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, req->rv, req->p,
+                              "acme problem %s: %s", ptype, pdetail);
+            }
+            return req->rv;
+        }
+    }
+    
+    switch (res->status) {
+        case 400:
+            return APR_EINVAL;
+        case 401: /* sectigo returns this instead of 403 */
+        case 403:
+            return APR_EACCES;
+        case 404:
+            return APR_ENOENT;
+        default:
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, 0, req->p,
+                          "acme problem unknown: http status %d", res->status);
+            md_result_printf(req->result, APR_EGENERAL, "unexpected http status: %d",
+                             res->status);
+            return req->result->status;
+    }
+    return APR_SUCCESS;
+}
+
+/**************************************************************************************************/
+/* ACME requests with nonce handling */
+
+static apr_status_t acmev2_req_init(md_acme_req_t *req, md_json_t *jpayload)
+{
+    md_data_t payload;
+
+    md_data_null(&payload);
+    if (!req->acme->acct) {
+        return APR_EINVAL;
+    }
+    if (jpayload) {
+        payload.data = md_json_writep(jpayload, req->p, MD_JSON_FMT_COMPACT);
+        if (!payload.data) {
+            return APR_EINVAL;
+        }
+    }
+    else {
+        payload.data = "";
+    }
+
+    payload.len = strlen(payload.data);
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, req->p, 
+                  "acme payload(len=%" APR_SIZE_T_FMT "): %s", payload.len, payload.data);
+    return md_jws_sign(&req->req_json, req->p, &payload,
+                       req->prot_fields, req->acme->acct_key, req->acme->acct->url);
+}
+
+apr_status_t md_acme_req_body_init(md_acme_req_t *req, md_json_t *payload)
+{
+    return req->acme->req_init_fn(req, payload);
+}
+
+static apr_status_t md_acme_req_done(md_acme_req_t *req, apr_status_t rv)
+{
+    if (req->result->status != APR_SUCCESS) {
+        if (req->on_err) {
+            req->on_err(req, req->result, req->baton);
+        }
+    }
+    /* An error in rv superceeds the result->status */
+    if (APR_SUCCESS != rv) req->result->status = rv;
+    rv = req->result->status;
+    /* transfer results into the acme's central result for longer life and later inspection */
+    md_result_dup(req->acme->last, req->result);
+    if (req->p) {
+        apr_pool_destroy(req->p);
+    }
+    return rv;
+}
+
+static apr_status_t on_response(const md_http_response_t *res, void *data)
+{
+    md_acme_req_t *req = data;
+    apr_status_t rv = APR_SUCCESS;
+    
+    req->resp_hdrs = apr_table_clone(req->p, res->headers);
+    req_update_nonce(req->acme, res->headers);
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, req->p, "response: %d", res->status);
+    if (res->status >= 200 && res->status < 300) {
+        int processed = 0;
+        
+        if (req->on_json) {
+            processed = 1;
+            rv = md_json_read_http(&req->resp_json, req->p, res);
+            if (APR_SUCCESS == rv) {
+                if (md_log_is_level(req->p, MD_LOG_TRACE2)) {
+                    const char *s;
+                    s = md_json_writep(req->resp_json, req->p, MD_JSON_FMT_INDENT);
+                    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, rv, req->p,
+                                  "response: %s",
+                                  s ? s : "<failed to serialize!>");
+                }
+                rv = req->on_json(req->acme, req->p, req->resp_hdrs, req->resp_json, req->baton);
+            }        
+            else if (APR_STATUS_IS_ENOENT(rv)) {
+                /* not JSON content, fall through */
+                processed = 0;
+            }
+            else {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, req->p, "parsing JSON body");
+            }
+        }
+        
+        if (!processed && req->on_res) {
+            processed = 1;
+            rv = req->on_res(req->acme, res, req->baton);
+        }
+        
+        if (!processed) {
+            rv = APR_EINVAL;
+            md_result_printf(req->result, rv, "unable to process the response: "
+                             "http-status=%d, content-type=%s", 
+                             res->status, apr_table_get(res->headers, "Content-Type"));
+            md_result_log(req->result, MD_LOG_ERR);
+        }
+    }
+    else if (APR_EAGAIN == (rv = inspect_problem(req, res))) {
+        /* leave req alive */
+        return rv;
+    }
+
+    md_acme_req_done(req, rv);
+    return rv;
+}
+
+static apr_status_t acmev2_GET_as_POST_init(md_acme_req_t *req, void *baton)
+{
+    (void)baton;
+    return md_acme_req_body_init(req, NULL);
+}
+
+static apr_status_t md_acme_req_send(md_acme_req_t *req)
+{
+    apr_status_t rv;
+    md_acme_t *acme = req->acme;
+    md_data_t *body = NULL;
+    md_result_t *result;
+
+    assert(acme->url);
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, req->p, 
+                  "sending req: %s %s", req->method, req->url);
+    md_result_reset(req->acme->last);
+    result = md_result_make(req->p, APR_SUCCESS);
+    
+    /* Whom are we talking to? */
+    if (acme->version == MD_ACME_VERSION_UNKNOWN) {
+        rv = md_acme_setup(acme, result);
+        if (APR_SUCCESS != rv) goto leave;
+    }
+    
+    if (!strcmp("GET", req->method) && !req->on_init && !req->req_json) {
+        /* See <https://ietf-wg-acme.github.io/acme/draft-ietf-acme-acme.html#rfc.section.6.3>
+         * and <https://mailarchive.ietf.org/arch/msg/acme/sotffSQ0OWV-qQJodLwWYWcEVKI>
+         * and <https://community.letsencrypt.org/t/acme-v2-scheduled-deprecation-of-unauthenticated-resource-gets/74380>
+         * We implement this change in ACMEv2 and higher as keeping the md_acme_GET() methods,
+         * but switching them to POSTs with a empty, JWS signed, body when we call
+         * our HTTP client. */
+        req->method = "POST";
+        req->on_init = acmev2_GET_as_POST_init;
+        /*req->max_retries = 0;  don't do retries on these "GET"s */
+    }
+    
+    /* Besides GET/HEAD, we always need a fresh nonce */
+    if (strcmp("GET", req->method) && strcmp("HEAD", req->method)) {
+        if (acme->version == MD_ACME_VERSION_UNKNOWN) {
+            rv = md_acme_setup(acme, result);
+            if (APR_SUCCESS != rv) goto leave;
+        }
+        if (!acme->nonce && (APR_SUCCESS != (rv = acme->new_nonce_fn(acme)))) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, req->p, 
+                          "error retrieving new nonce from ACME server");
+            goto leave;
+        }
+
+        md_json_sets(acme->nonce, req->prot_fields, "nonce", NULL);
+        md_json_sets(req->url, req->prot_fields, "url", NULL);
+        acme->nonce = NULL;
+    }
+    
+    rv = req->on_init? req->on_init(req, req->baton) : APR_SUCCESS;
+    if (APR_SUCCESS != rv) goto leave;
+    
+    if (req->req_json) {
+        body = apr_pcalloc(req->p, sizeof(*body));
+        body->data = md_json_writep(req->req_json, req->p, MD_JSON_FMT_INDENT);
+        body->len = strlen(body->data);
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, req->p,
+                      "sending JSON body: %s", body->data);
+    }
+
+    if (body && md_log_is_level(req->p, MD_LOG_TRACE4)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, req->p,
+                      "req: %s %s, body:\n%s", req->method, req->url, body->data);
+    }
+    else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, req->p, 
+                      "req: %s %s", req->method, req->url);
+    }
+    
+    if (!strcmp("GET", req->method)) {
+        rv = md_http_GET_perform(req->acme->http, req->url, NULL, on_response, req);
+    }
+    else if (!strcmp("POST", req->method)) {
+        rv = md_http_POSTd_perform(req->acme->http, req->url, NULL, "application/jose+json",  
+                                   body, on_response, req);
+    }
+    else if (!strcmp("HEAD", req->method)) {
+        rv = md_http_HEAD_perform(req->acme->http, req->url, NULL, on_response, req);
+    }
+    else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, req->p, 
+                      "HTTP method %s against: %s", req->method, req->url);
+        rv = APR_ENOTIMPL;
+    }
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, req->p, "req sent");
+    
+    if (APR_EAGAIN == rv && req->max_retries > 0) {
+        --req->max_retries;
+        rv = md_acme_req_send(req);
+    }
+    req = NULL;
+
+leave:
+    if (req) md_acme_req_done(req, rv);
+    return rv;
+}
+
+apr_status_t md_acme_POST(md_acme_t *acme, const char *url,
+                          md_acme_req_init_cb *on_init,
+                          md_acme_req_json_cb *on_json,
+                          md_acme_req_res_cb *on_res,
+                          md_acme_req_err_cb *on_err,
+                          void *baton)
+{
+    md_acme_req_t *req;
+    
+    assert(url);
+    assert(on_json || on_res);
+
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, acme->p, "add acme POST: %s", url);
+    req = md_acme_req_create(acme, "POST", url);
+    req->on_init = on_init;
+    req->on_json = on_json;
+    req->on_res = on_res;
+    req->on_err = on_err;
+    req->baton = baton;
+    
+    return md_acme_req_send(req);
+}
+
+apr_status_t md_acme_GET(md_acme_t *acme, const char *url,
+                         md_acme_req_init_cb *on_init,
+                         md_acme_req_json_cb *on_json,
+                         md_acme_req_res_cb *on_res,
+                          md_acme_req_err_cb *on_err,
+                         void *baton)
+{
+    md_acme_req_t *req;
+    
+    assert(url);
+    assert(on_json || on_res);
+
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, acme->p, "add acme GET: %s", url);
+    req = md_acme_req_create(acme, "GET", url);
+    req->on_init = on_init;
+    req->on_json = on_json;
+    req->on_res = on_res;
+    req->on_err = on_err;
+    req->baton = baton;
+    
+    return md_acme_req_send(req);
+}
+
+void md_acme_report_result(md_acme_t *acme, apr_status_t rv, struct md_result_t *result)
+{
+    if (acme->last->status == APR_SUCCESS) {
+        md_result_set(result, rv, NULL);
+    }
+    else {
+        md_result_problem_set(result, acme->last->status, acme->last->problem, 
+                              acme->last->detail, acme->last->subproblems);
+    }
+}
+
+/**************************************************************************************************/
+/* GET JSON */
+
+typedef struct {
+    apr_pool_t *pool;
+    md_json_t *json;
+} json_ctx;
+
+static apr_status_t on_got_json(md_acme_t *acme, apr_pool_t *p, const apr_table_t *headers, 
+                                md_json_t *jbody, void *baton)
+{
+    json_ctx *ctx = baton;
+
+    (void)acme;
+    (void)p;
+    (void)headers;
+    ctx->json = md_json_clone(ctx->pool, jbody);
+    return APR_SUCCESS;
+}
+
+apr_status_t md_acme_get_json(struct md_json_t **pjson, md_acme_t *acme, 
+                              const char *url, apr_pool_t *p)
+{
+    apr_status_t rv;
+    json_ctx ctx;
+    
+    ctx.pool = p;
+    ctx.json = NULL;
+    
+    rv = md_acme_GET(acme, url, NULL, on_got_json, NULL, NULL, &ctx);
+    *pjson = (APR_SUCCESS == rv)? ctx.json : NULL;
+    return rv;
+}
+
+/**************************************************************************************************/
+/* Generic ACME operations */
+
+void md_acme_clear_acct(md_acme_t *acme)
+{
+    acme->acct_id = NULL;
+    acme->acct = NULL;
+    acme->acct_key = NULL;
+}
+
+const char *md_acme_acct_id_get(md_acme_t *acme)
+{
+    return acme->acct_id;
+}
+
+const char *md_acme_acct_url_get(md_acme_t *acme)
+{
+    return acme->acct? acme->acct->url : NULL;
+}
+
+apr_status_t md_acme_use_acct(md_acme_t *acme, md_store_t *store,
+                              apr_pool_t *p, const char *acct_id)
+{
+    md_acme_acct_t *acct;
+    md_pkey_t *pkey;
+    apr_status_t rv;
+
+    if (APR_SUCCESS == (rv = md_acme_acct_load(&acct, &pkey,
+                                               store, MD_SG_ACCOUNTS, acct_id, acme->p))) {
+        if (md_acme_acct_matches_url(acct, acme->url)) {
+            acme->acct_id = apr_pstrdup(p, acct_id);
+            acme->acct = acct;
+            acme->acct_key = pkey;
+            rv = md_acme_acct_validate(acme, store, p);
+        }
+        else {
+            /* account is from another server or, more likely, from another
+             * protocol endpoint on the same server */
+            rv = APR_ENOENT;
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_acme_use_acct_for_md(md_acme_t *acme, struct md_store_t *store,
+                                     apr_pool_t *p, const char *acct_id,
+                                     const md_t *md)
+{
+    md_acme_acct_t *acct;
+    md_pkey_t *pkey;
+    apr_status_t rv;
+
+    if (APR_SUCCESS == (rv = md_acme_acct_load(&acct, &pkey,
+                                               store, MD_SG_ACCOUNTS, acct_id, acme->p))) {
+        if (md_acme_acct_matches_md(acct, md)) {
+            acme->acct_id = apr_pstrdup(p, acct_id);
+            acme->acct = acct;
+            acme->acct_key = pkey;
+            rv = md_acme_acct_validate(acme, store, p);
+        }
+        else {
+            /* account is from another server or, more likely, from another
+             * protocol endpoint on the same server */
+            rv = APR_ENOENT;
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_acme_save_acct(md_acme_t *acme, apr_pool_t *p, md_store_t *store)
+{
+    return md_acme_acct_save(store, p, acme, &acme->acct_id, acme->acct, acme->acct_key);
+}
+
+static apr_status_t acmev2_POST_new_account(md_acme_t *acme,
+                                            md_acme_req_init_cb *on_init,
+                                            md_acme_req_json_cb *on_json,
+                                            md_acme_req_res_cb *on_res,
+                                            md_acme_req_err_cb *on_err,
+                                            void *baton)
+{
+    return md_acme_POST(acme, acme->api.v2.new_account, on_init, on_json, on_res, on_err, baton);
+}
+
+apr_status_t md_acme_POST_new_account(md_acme_t *acme, 
+                                      md_acme_req_init_cb *on_init,
+                                      md_acme_req_json_cb *on_json,
+                                      md_acme_req_res_cb *on_res,
+                                      md_acme_req_err_cb *on_err,
+                                      void *baton)
+{
+    return acme->post_new_account_fn(acme, on_init, on_json, on_res, on_err, baton);
+}
+
+/**************************************************************************************************/
+/* ACME setup */
+
+apr_status_t md_acme_create(md_acme_t **pacme, apr_pool_t *p, const char *url,
+                            const char *proxy_url, const char *ca_file)
+{
+    md_acme_t *acme;
+    const char *err = NULL;
+    apr_status_t rv;
+    apr_uri_t uri_parsed;
+    size_t len;
+    
+    if (!url) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, APR_EINVAL, p, "create ACME without url");
+        return APR_EINVAL;
+    }
+    
+    if (APR_SUCCESS != (rv = md_util_abs_uri_check(p, url, &err))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "invalid ACME uri (%s): %s", err, url);
+        return rv;
+    }
+    
+    acme = apr_pcalloc(p, sizeof(*acme));
+    acme->url = url;
+    acme->p = p;
+    acme->user_agent = apr_psprintf(p, "%s mod_md/%s", 
+                                    base_product, MOD_MD_VERSION);
+    acme->proxy_url = proxy_url? apr_pstrdup(p, proxy_url) : NULL;
+    acme->max_retries = 99;
+    acme->ca_file = ca_file;
+
+    if (APR_SUCCESS != (rv = apr_uri_parse(p, url, &uri_parsed))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "parsing ACME uri: %s", url);
+        return APR_EINVAL;
+    }
+    
+    len = strlen(uri_parsed.hostname);
+    acme->sname = (len <= 16)? uri_parsed.hostname : apr_pstrdup(p, uri_parsed.hostname + len - 16);
+    acme->version = MD_ACME_VERSION_UNKNOWN;
+    acme->last = md_result_make(acme->p, APR_SUCCESS);
+    
+    *pacme = acme;
+    return rv;
+}
+
+typedef struct {
+    md_acme_t *acme;
+    md_result_t *result;
+} update_dir_ctx;
+
+static apr_status_t update_directory(const md_http_response_t *res, void *data)
+{
+    md_http_request_t *req = res->req;
+    md_acme_t *acme = ((update_dir_ctx *)data)->acme;
+    md_result_t *result = ((update_dir_ctx *)data)->result;
+    apr_status_t rv;
+    md_json_t *json;
+    const char *s;
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, req->pool, "directory lookup response: %d", res->status);
+    if (res->status == 503) {
+        md_result_printf(result, APR_EAGAIN,
+            "The ACME server at <%s> reports that Service is Unavailable (503). This "
+            "may happen during maintenance for short periods of time.", acme->url); 
+        md_result_log(result, MD_LOG_INFO);
+        rv = result->status;
+        goto leave;
+    }
+    else if (res->status < 200 || res->status >= 300) {
+        md_result_printf(result, APR_EAGAIN,
+            "The ACME server at <%s> responded with HTTP status %d. This "
+            "is unusual. Please verify that the URL is correct and that you can indeed "
+            "make request from the server to it by other means, e.g. invoking curl/wget.", 
+            acme->url, res->status);
+        rv = result->status;
+        goto leave;
+    }
+    
+    rv = md_json_read_http(&json, req->pool, res);
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, req->pool, "reading JSON body");
+        goto leave;
+    }
+    
+    if (md_log_is_level(acme->p, MD_LOG_TRACE2)) {
+        s = md_json_writep(json, req->pool, MD_JSON_FMT_INDENT);
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, rv, req->pool,
+                      "response: %s", s ? s : "<failed to serialize!>");
+    }
+    
+    /* What have we got? */
+    if ((s = md_json_dups(acme->p, json, "newAccount", NULL))) {
+        acme->api.v2.new_account = s;
+        acme->api.v2.new_order = md_json_dups(acme->p, json, "newOrder", NULL);
+        acme->api.v2.revoke_cert = md_json_dups(acme->p, json, "revokeCert", NULL);
+        acme->api.v2.key_change = md_json_dups(acme->p, json, "keyChange", NULL);
+        acme->api.v2.new_nonce = md_json_dups(acme->p, json, "newNonce", NULL);
+        /* RFC 8555 only requires "directory" and "newNonce" resources.
+         * mod_md uses "newAccount" and "newOrder" so check for them.
+         * But mod_md does not use the "revokeCert" or "keyChange"
+         * resources, so tolerate the absence of those keys.  In the
+         * future if mod_md implements revocation or key rollover then
+         * the use of those features should be predicated on the
+         * server's advertised capabilities. */
+        if (acme->api.v2.new_account
+            && acme->api.v2.new_order
+            && acme->api.v2.new_nonce) {
+            acme->version = MD_ACME_VERSION_2;
+        }
+        acme->ca_agreement = md_json_dups(acme->p, json, "meta", MD_KEY_TOS, NULL);
+        acme->eab_required = md_json_getb(json, "meta", MD_KEY_EAB_REQUIRED, NULL);
+        acme->new_nonce_fn = acmev2_new_nonce;
+        acme->req_init_fn = acmev2_req_init;
+        acme->post_new_account_fn = acmev2_POST_new_account;
+    }
+    else if ((s = md_json_dups(acme->p, json, "new-authz", NULL))) {
+        acme->api.v1.new_authz = s;
+        acme->api.v1.new_cert = md_json_dups(acme->p, json, "new-cert", NULL);
+        acme->api.v1.new_reg = md_json_dups(acme->p, json, "new-reg", NULL);
+        acme->api.v1.revoke_cert = md_json_dups(acme->p, json, "revoke-cert", NULL);
+        if (acme->api.v1.new_authz && acme->api.v1.new_cert
+            && acme->api.v1.new_reg && acme->api.v1.revoke_cert) {
+            acme->version = MD_ACME_VERSION_1;
+        }
+        acme->ca_agreement = md_json_dups(acme->p, json, "meta", "terms-of-service", NULL);
+        /* we init that far, but will not use the v1 api */
+    }
+
+    if (MD_ACME_VERSION_UNKNOWN == acme->version) {
+        md_result_printf(result, APR_EINVAL,
+            "Unable to understand ACME server response from <%s>. "
+            "Wrong ACME protocol version or link?", acme->url); 
+        md_result_log(result, MD_LOG_WARNING);
+        rv = result->status;
+    }
+leave:
+    return rv;
+}
+
+apr_status_t md_acme_setup(md_acme_t *acme, md_result_t *result)
+{
+    apr_status_t rv;
+    update_dir_ctx ctx;
+   
+    assert(acme->url);
+    acme->version = MD_ACME_VERSION_UNKNOWN;
+    
+    if (!acme->http && APR_SUCCESS != (rv = md_http_create(&acme->http, acme->p,
+                                                           acme->user_agent, acme->proxy_url))) {
+        return rv;
+    }
+    /* TODO: maybe this should be configurable. Let's take some reasonable 
+     * defaults for now that protect our client */
+    md_http_set_response_limit(acme->http, 1024*1024);
+    md_http_set_timeout_default(acme->http, apr_time_from_sec(10 * 60));
+    md_http_set_connect_timeout_default(acme->http, apr_time_from_sec(30));
+    md_http_set_stalling_default(acme->http, 10, apr_time_from_sec(30));
+    md_http_set_ca_file(acme->http, acme->ca_file);
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, acme->p, "get directory from %s", acme->url);
+    
+    ctx.acme = acme;
+    ctx.result = result;
+    rv = md_http_GET_perform(acme->http, acme->url, NULL, update_directory, &ctx);
+    
+    if (APR_SUCCESS != rv && APR_SUCCESS == result->status) {
+        /* If the result reports no error, we never got a response from the server */
+        md_result_printf(result, rv, 
+            "Unsuccessful in contacting ACME server at <%s>. If this problem persists, "
+            "please check your network connectivity from your Apache server to the "
+            "ACME server. Also, older servers might have trouble verifying the certificates "
+            "of the ACME server. You can check if you are able to contact it manually via the "
+            "curl command. Sometimes, the ACME server might be down for maintenance, "
+            "so failing to contact it is not an immediate problem. Apache will "
+            "continue retrying this.", acme->url);
+        md_result_log(result, MD_LOG_WARNING);
+    }
+    return rv;
+}
+
+
diff --git a/modules/md/md_acme.h b/modules/md/md_acme.h
new file mode 100644
index 0000000..f28f2b6
--- /dev/null
+++ b/modules/md/md_acme.h
@@ -0,0 +1,317 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_acme_h
+#define mod_md_md_acme_h
+
+struct apr_array_header_t;
+struct apr_bucket_brigade;
+struct md_http_response_t;
+struct apr_hash_t;
+struct md_http_t;
+struct md_json_t;
+struct md_pkey_t;
+struct md_t;
+struct md_acme_acct_t;
+struct md_acmev2_acct_t;
+struct md_store_t;
+struct md_result_t;
+
+#define MD_PROTO_ACME               "ACME"
+
+#define MD_AUTHZ_CHA_HTTP_01        "http-01"
+#define MD_AUTHZ_CHA_SNI_01         "tls-sni-01"
+
+#define MD_ACME_VERSION_UNKNOWN    0x0
+#define MD_ACME_VERSION_1          0x010000
+#define MD_ACME_VERSION_2          0x020000
+
+#define MD_ACME_VERSION_MAJOR(i)    (((i)&0xFF0000) >> 16)
+
+typedef enum {
+    MD_ACME_S_UNKNOWN,              /* MD has not been analysed yet */
+    MD_ACME_S_REGISTERED,           /* MD is registered at CA, but not more */
+    MD_ACME_S_TOS_ACCEPTED,         /* Terms of Service were accepted by account holder */
+    MD_ACME_S_CHALLENGED,           /* MD challenge information for all domains is known */
+    MD_ACME_S_VALIDATED,            /* MD domains have been validated */
+    MD_ACME_S_CERTIFIED,            /* MD has valid certificate */
+    MD_ACME_S_DENIED,               /* MD domains (at least one) have been denied by CA */
+} md_acme_state_t;
+
+typedef struct md_acme_t md_acme_t;
+
+typedef struct md_acme_req_t md_acme_req_t;
+/**
+ * Request callback on a successful HTTP response (status 2xx).
+ */
+typedef apr_status_t md_acme_req_res_cb(md_acme_t *acme, 
+                                        const struct md_http_response_t *res, void *baton);
+
+/**
+ * Request callback to initialize before sending. May be invoked more than once in
+ * case of retries.
+ */
+typedef apr_status_t md_acme_req_init_cb(md_acme_req_t *req, void *baton);
+
+/**
+ * Request callback on a successful response (HTTP response code 2xx) and content
+ * type matching application/.*json.
+ */
+typedef apr_status_t md_acme_req_json_cb(md_acme_t *acme, apr_pool_t *p, 
+                                         const apr_table_t *headers, 
+                                         struct md_json_t *jbody, void *baton);
+
+/**
+ * Request callback on detected errors.
+ */
+typedef apr_status_t md_acme_req_err_cb(md_acme_req_t *req, 
+                                        const struct md_result_t *result, void *baton);
+
+
+typedef apr_status_t md_acme_new_nonce_fn(md_acme_t *acme);
+typedef apr_status_t md_acme_req_init_fn(md_acme_req_t *req, struct md_json_t *jpayload);
+
+typedef apr_status_t md_acme_post_fn(md_acme_t *acme, 
+                                     md_acme_req_init_cb *on_init,
+                                     md_acme_req_json_cb *on_json,
+                                     md_acme_req_res_cb *on_res,
+                                     md_acme_req_err_cb *on_err,
+                                     void *baton);
+
+struct md_acme_t {
+    const char *url;                /* directory url of the ACME service */
+    const char *sname;              /* short name for the service, not necessarily unique */
+    apr_pool_t *p;
+    const char *user_agent;
+    const char *proxy_url;
+    const char *ca_file;
+    
+    const char *acct_id;            /* local storage id account was loaded from or NULL */
+    struct md_acme_acct_t *acct;    /* account at ACME server to use for requests */
+    struct md_pkey_t *acct_key;     /* private RSA key belonging to account */
+    
+    int version;                    /* as detected from the server */
+    union {
+        struct { /* obsolete */
+            const char *new_authz;
+            const char *new_cert;
+            const char *new_reg;
+            const char *revoke_cert;
+            
+        } v1;
+        struct {
+            const char *new_account;
+            const char *new_order;
+            const char *key_change;
+            const char *revoke_cert;
+            const char *new_nonce;
+        } v2;
+    } api;
+    const char *ca_agreement;
+    const char *acct_name;
+    int eab_required;
+    
+    md_acme_new_nonce_fn *new_nonce_fn;
+    md_acme_req_init_fn *req_init_fn;
+    md_acme_post_fn *post_new_account_fn;
+    
+    struct md_http_t *http;
+    
+    const char *nonce;
+    int max_retries;
+    struct md_result_t *last;      /* result of last request */
+};
+
+/**
+ * Global init, call once at start up.
+ */
+apr_status_t md_acme_init(apr_pool_t *pool, const char *base_version, int init_ssl);
+
+/**
+ * Create a new ACME server instance. If path is not NULL, will use that directory
+ * for persisting information. Will load any information persisted in earlier session.
+ * url needs only be specified for instances where this has never been persisted before.
+ *
+ * @param pacme   will hold the ACME server instance on success
+ * @param p       pool to used
+ * @param url     url of the server, optional if known at path
+ * @param proxy_url optional url of a HTTP(S) proxy to use
+ */
+apr_status_t md_acme_create(md_acme_t **pacme, apr_pool_t *p, const char *url,
+                            const char *proxy_url, const char *ca_file);
+
+/**
+ * Contact the ACME server and retrieve its directory information.
+ * 
+ * @param acme    the ACME server to contact
+ */
+apr_status_t md_acme_setup(md_acme_t *acme, struct md_result_t *result);
+
+void md_acme_report_result(md_acme_t *acme, apr_status_t rv, struct md_result_t *result);
+
+/**************************************************************************************************/
+/* account handling */
+
+/**
+ * Clear any existing account data from acme instance.
+ */
+void md_acme_clear_acct(md_acme_t *acme);
+
+apr_status_t md_acme_POST_new_account(md_acme_t *acme, 
+                                      md_acme_req_init_cb *on_init,
+                                      md_acme_req_json_cb *on_json,
+                                      md_acme_req_res_cb *on_res,
+                                      md_acme_req_err_cb *on_err,
+                                      void *baton);
+
+/**
+ * Get the local name of the account currently used by the acme instance.
+ * Will be NULL if no account has been setup successfully.
+ */
+const char *md_acme_acct_id_get(md_acme_t *acme);
+const char *md_acme_acct_url_get(md_acme_t *acme);
+
+/** 
+ * Specify the account to use by name in local store. On success, the account
+ * is the "current" one used by the acme instance.
+ * @param acme the acme instance to set the account for
+ * @param store the store to load accounts from
+ * @param p pool for allocations
+ * @param acct_id name of the account to load
+ */
+apr_status_t md_acme_use_acct(md_acme_t *acme, struct md_store_t *store, 
+                              apr_pool_t *p, const char *acct_id);
+
+/**
+ * Specify the account to use for a specific MD by name in local store.
+ * On success, the account is the "current" one used by the acme instance.
+ * @param acme the acme instance to set the account for
+ * @param store the store to load accounts from
+ * @param p pool for allocations
+ * @param acct_id name of the account to load
+ * @param md the MD the account shall be used for
+ */
+apr_status_t md_acme_use_acct_for_md(md_acme_t *acme, struct md_store_t *store,
+                                     apr_pool_t *p, const char *acct_id,
+                                     const md_t *md);
+
+/**
+ * Get the local name of the account currently used by the acme instance.
+ * Will be NULL if no account has been setup successfully.
+ */
+const char *md_acme_acct_id_get(md_acme_t *acme);
+
+/**
+ * Agree to the given Terms-of-Service url for the current account.
+ */
+apr_status_t md_acme_agree(md_acme_t *acme, apr_pool_t *p, const char *tos);
+
+/**
+ * Confirm with the server that the current account agrees to the Terms-of-Service
+ * given in the agreement url.
+ * If the known agreement is equal to this, nothing is done.
+ * If it differs, the account is re-validated in the hope that the server
+ * announces the Tos URL it wants. If this is equal to the agreement specified,
+ * the server is notified of this. If the server requires a ToS that the account
+ * thinks it has already given, it is resend.
+ *
+ * If an agreement is required, different from the current one, APR_INCOMPLETE is
+ * returned and the agreement url is returned in the parameter.
+ */
+apr_status_t md_acme_check_agreement(md_acme_t *acme, apr_pool_t *p, 
+                                     const char *agreement, const char **prequired);
+
+apr_status_t md_acme_save_acct(md_acme_t *acme, apr_pool_t *p, struct md_store_t *store);
+                               
+/**
+ * Deactivate the current account at the ACME server.. 
+ */
+apr_status_t md_acme_acct_deactivate(md_acme_t *acme, apr_pool_t *p);
+
+/**************************************************************************************************/
+/* request handling */
+
+struct md_acme_req_t {
+    md_acme_t *acme;               /* the ACME server to talk to */
+    apr_pool_t *p;                 /* pool for the request duration */
+    
+    const char *url;               /* url to POST the request to */
+    const char *method;            /* HTTP method to use */
+    struct md_json_t *prot_fields; /* JWS protected fields */
+    struct md_json_t *req_json;    /* JSON to be POSTed in request body */
+
+    apr_table_t *resp_hdrs;        /* HTTP response headers */
+    struct md_json_t *resp_json;   /* JSON response body received */
+    
+    apr_status_t rv;               /* status of request */
+    
+    md_acme_req_init_cb *on_init;  /* callback to initialize the request before submit */
+    md_acme_req_json_cb *on_json;  /* callback on successful JSON response */
+    md_acme_req_res_cb *on_res;    /* callback on generic HTTP response */
+    md_acme_req_err_cb *on_err;    /* callback on encountered error */
+    int max_retries;               /* how often this might be retried */
+    void *baton;                   /* userdata for callbacks */
+    struct md_result_t *result;    /* result of this request */
+};
+
+apr_status_t md_acme_req_body_init(md_acme_req_t *req, struct md_json_t *payload);
+
+apr_status_t md_acme_GET(md_acme_t *acme, const char *url,
+                         md_acme_req_init_cb *on_init,
+                         md_acme_req_json_cb *on_json,
+                         md_acme_req_res_cb *on_res,
+                         md_acme_req_err_cb *on_err,
+                         void *baton);
+/**
+ * Perform a POST against the ACME url. If a on_json callback is given and
+ * the HTTP response is JSON, only this callback is invoked. Otherwise, on HTTP status
+ * 2xx, the on_res callback is invoked. If no on_res is given, it is considered a
+ * response error, since only JSON was expected.
+ * At least one callback needs to be non-NULL.
+ * 
+ * @param acme        the ACME server to talk to
+ * @param url         the url to send the request to
+ * @param on_init     callback to initialize the request data
+ * @param on_json     callback on successful JSON response
+ * @param on_res      callback on successful HTTP response
+ * @param baton       userdata for callbacks
+ */
+apr_status_t md_acme_POST(md_acme_t *acme, const char *url,
+                          md_acme_req_init_cb *on_init,
+                          md_acme_req_json_cb *on_json,
+                          md_acme_req_res_cb *on_res,
+                          md_acme_req_err_cb *on_err,
+                          void *baton);
+
+/**
+ * Retrieve a JSON resource from the ACME server 
+ */
+apr_status_t md_acme_get_json(struct md_json_t **pjson, md_acme_t *acme, 
+                              const char *url, apr_pool_t *p);
+
+
+apr_status_t md_acme_req_body_init(md_acme_req_t *req, struct md_json_t *jpayload);
+
+apr_status_t md_acme_protos_add(struct apr_hash_t *protos, apr_pool_t *p);
+
+/**
+ * Return != 0 iff the given problem identifier is an ACME error string
+ * indicating something is wrong with the input values, e.g. from our
+ * configuration.
+ */
+int md_acme_problem_is_input_related(const char *problem);
+
+#endif /* md_acme_h */
diff --git a/modules/md/md_acme_acct.c b/modules/md/md_acme_acct.c
new file mode 100644
index 0000000..f3e043e
--- /dev/null
+++ b/modules/md/md_acme_acct.c
@@ -0,0 +1,749 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stdio.h>
+
+#include <apr_lib.h>
+#include <apr_file_info.h>
+#include <apr_file_io.h>
+#include <apr_fnmatch.h>
+#include <apr_hash.h>
+#include <apr_strings.h>
+#include <apr_tables.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_jws.h"
+#include "md_log.h"
+#include "md_result.h"
+#include "md_store.h"
+#include "md_util.h"
+#include "md_version.h"
+
+#include "md_acme.h"
+#include "md_acme_acct.h"
+
+static apr_status_t acct_make(md_acme_acct_t **pacct, apr_pool_t *p, 
+                              const char *ca_url, apr_array_header_t *contacts)
+{
+    md_acme_acct_t *acct;
+    
+    acct = apr_pcalloc(p, sizeof(*acct));
+    acct->ca_url = ca_url;
+    if (!contacts || apr_is_empty_array(contacts)) {
+        acct->contacts = apr_array_make(p, 5, sizeof(const char *));
+    }
+    else {
+        acct->contacts = apr_array_copy(p, contacts);
+    }
+    
+    *pacct = acct;
+    return APR_SUCCESS;
+}
+
+
+static const char *mk_acct_id(apr_pool_t *p, md_acme_t *acme, int i)
+{
+    return apr_psprintf(p, "ACME-%s-%04d", acme->sname, i);
+}
+
+static const char *mk_acct_pattern(apr_pool_t *p, md_acme_t *acme)
+{
+    return apr_psprintf(p, "ACME-%s-*", acme->sname);
+}
+ 
+/**************************************************************************************************/
+/* json load/save */
+
+static md_acme_acct_st acct_st_from_str(const char *s) 
+{
+    if (s) {
+        if (!strcmp("valid", s)) {
+            return MD_ACME_ACCT_ST_VALID;
+        }
+        else if (!strcmp("deactivated", s)) {
+            return MD_ACME_ACCT_ST_DEACTIVATED;
+        }
+        else if (!strcmp("revoked", s)) {
+            return MD_ACME_ACCT_ST_REVOKED;
+        }
+    }
+    return MD_ACME_ACCT_ST_UNKNOWN;
+}
+
+md_json_t *md_acme_acct_to_json(md_acme_acct_t *acct, apr_pool_t *p)
+{
+    md_json_t *jacct;
+    const char *s;
+
+    assert(acct);
+    jacct = md_json_create(p);
+    switch (acct->status) {
+        case MD_ACME_ACCT_ST_VALID:
+            s = "valid";
+            break;
+        case MD_ACME_ACCT_ST_DEACTIVATED:
+            s = "deactivated";
+            break;
+        case MD_ACME_ACCT_ST_REVOKED:
+            s = "revoked";
+            break;
+        default:
+            s = NULL;
+            break;
+    }    
+    if (s) md_json_sets(s, jacct, MD_KEY_STATUS, NULL);
+    if (acct->url) md_json_sets(acct->url, jacct, MD_KEY_URL, NULL);
+    if (acct->ca_url) md_json_sets(acct->ca_url, jacct, MD_KEY_CA_URL, NULL);
+    if (acct->contacts) md_json_setsa(acct->contacts, jacct, MD_KEY_CONTACT, NULL);
+    if (acct->registration) md_json_setj(acct->registration, jacct, MD_KEY_REGISTRATION, NULL);
+    if (acct->agreement) md_json_sets(acct->agreement, jacct, MD_KEY_AGREEMENT, NULL);
+    if (acct->orders) md_json_sets(acct->orders, jacct, MD_KEY_ORDERS, NULL);
+    if (acct->eab_kid) md_json_sets(acct->eab_kid, jacct, MD_KEY_EAB, MD_KEY_KID, NULL);
+    if (acct->eab_hmac) md_json_sets(acct->eab_hmac, jacct, MD_KEY_EAB, MD_KEY_HMAC, NULL);
+
+    return jacct;
+}
+
+apr_status_t md_acme_acct_from_json(md_acme_acct_t **pacct, md_json_t *json, apr_pool_t *p)
+{
+    apr_status_t rv = APR_EINVAL;
+    md_acme_acct_t *acct;
+    md_acme_acct_st status = MD_ACME_ACCT_ST_UNKNOWN;
+    const char *ca_url, *url;
+    apr_array_header_t *contacts;
+    
+    if (md_json_has_key(json, MD_KEY_STATUS, NULL)) {
+        status = acct_st_from_str(md_json_gets(json, MD_KEY_STATUS, NULL));
+    }
+
+    url = md_json_gets(json, MD_KEY_URL, NULL);
+    if (!url) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, "account has no url");
+        goto leave;
+    }
+
+    ca_url = md_json_gets(json, MD_KEY_CA_URL, NULL);
+    if (!ca_url) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, "account has no CA url: %s", url);
+        goto leave;
+    }
+    
+    contacts = apr_array_make(p, 5, sizeof(const char *));
+    if (md_json_has_key(json, MD_KEY_CONTACT, NULL)) {
+        md_json_getsa(contacts, json, MD_KEY_CONTACT, NULL);
+    }
+    else {
+        md_json_getsa(contacts, json, MD_KEY_REGISTRATION, MD_KEY_CONTACT, NULL);
+    }
+    rv = acct_make(&acct, p, ca_url, contacts);
+    if (APR_SUCCESS != rv) goto leave;
+
+    acct->status = status;
+    acct->url = url;
+    acct->agreement = md_json_gets(json, MD_KEY_AGREEMENT, NULL);
+    if (!acct->agreement) {
+        /* backward compatible check */
+        acct->agreement = md_json_gets(json, "terms-of-service", NULL);
+    }
+    acct->orders = md_json_gets(json, MD_KEY_ORDERS, NULL);
+    if (md_json_has_key(json, MD_KEY_EAB, MD_KEY_KID, NULL)
+        && md_json_has_key(json, MD_KEY_EAB, MD_KEY_HMAC, NULL)) {
+        acct->eab_kid = md_json_gets(json, MD_KEY_EAB, MD_KEY_KID, NULL);
+        acct->eab_hmac = md_json_gets(json, MD_KEY_EAB, MD_KEY_HMAC, NULL);
+    }
+
+leave:
+    *pacct = (APR_SUCCESS == rv)? acct : NULL;
+    return rv;
+}
+
+apr_status_t md_acme_acct_save(md_store_t *store, apr_pool_t *p, md_acme_t *acme, 
+                               const char **pid, md_acme_acct_t *acct, md_pkey_t *acct_key)
+{
+    md_json_t *jacct;
+    apr_status_t rv;
+    int i;
+    const char *id = pid? *pid : NULL;
+    
+    jacct = md_acme_acct_to_json(acct, p);
+    if (id) {
+        rv = md_store_save(store, p, MD_SG_ACCOUNTS, id, MD_FN_ACCOUNT, MD_SV_JSON, jacct, 0);
+    }
+    else {
+        rv = APR_EAGAIN;
+        for (i = 0; i < 1000 && APR_SUCCESS != rv; ++i) {
+            id = mk_acct_id(p, acme, i);
+            rv = md_store_save(store, p, MD_SG_ACCOUNTS, id, MD_FN_ACCOUNT, MD_SV_JSON, jacct, 1);
+        }
+    }
+    if (APR_SUCCESS == rv) {
+        if (pid) *pid = id;
+        rv = md_store_save(store, p, MD_SG_ACCOUNTS, id, MD_FN_ACCT_KEY, MD_SV_PKEY, acct_key, 0);
+    }
+    return rv;
+}
+
+apr_status_t md_acme_acct_load(md_acme_acct_t **pacct, md_pkey_t **ppkey,
+                               md_store_t *store, md_store_group_t group, 
+                               const char *name, apr_pool_t *p)
+{
+    md_json_t *json;
+    apr_status_t rv;
+
+    rv = md_store_load_json(store, group, name, MD_FN_ACCOUNT, &json, p);
+    if (APR_STATUS_IS_ENOENT(rv)) {
+        goto out;
+    }
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "error reading account: %s", name);
+        goto out;
+    }
+    
+    rv = md_acme_acct_from_json(pacct, json, p);
+    if (APR_SUCCESS == rv) {
+        rv = md_store_load(store, group, name, MD_FN_ACCT_KEY, MD_SV_PKEY, (void**)ppkey, p);
+        if (APR_SUCCESS != rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "loading key: %s", name);
+            goto out;
+        }
+    }
+out:
+    if (APR_SUCCESS != rv) {
+        *pacct = NULL;
+        *ppkey = NULL;
+    } 
+    return rv;
+}
+
+/**************************************************************************************************/
+/* Lookup */
+
+int md_acme_acct_matches_url(md_acme_acct_t *acct, const char *url)
+{
+    /* The ACME url must match exactly */
+    if (!url || !acct->ca_url || strcmp(acct->ca_url, url)) return 0;
+    return 1;
+}
+
+int md_acme_acct_matches_md(md_acme_acct_t *acct, const md_t *md)
+{
+    if (!md_acme_acct_matches_url(acct, md->ca_effective)) return 0;
+    /* if eab values are not mentioned, we match an account regardless
+     * if it was registered with eab or not */
+    if (!md->ca_eab_kid || !md->ca_eab_hmac) {
+        /* No eab only acceptable when no eab is asked for.
+         * This prevents someone that has no external account binding
+         * to re-use an account from another MDomain that was created
+         * with a binding. */
+        return !acct->eab_kid || !acct->eab_hmac;
+    }
+    /* But of eab is asked for, we need an acct that matches exactly.
+     * When someone configures a new EAB and we need
+     * to created a new account for it. */
+    if (!acct->eab_kid || !acct->eab_hmac) return 0;
+    return !strcmp(acct->eab_kid, md->ca_eab_kid)
+           && !strcmp(acct->eab_hmac, md->ca_eab_hmac);
+}
+
+typedef struct {
+    apr_pool_t *p;
+    const md_t *md;
+    const char *id;
+} find_ctx;
+
+static int find_acct(void *baton, const char *name, const char *aspect,
+                     md_store_vtype_t vtype, void *value, apr_pool_t *ptemp)
+{
+    find_ctx *ctx = baton;
+    md_acme_acct_t *acct;
+    apr_status_t rv;
+
+    (void)aspect;
+    (void)ptemp;
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, ctx->p, "account candidate %s/%s", name, aspect); 
+    if (MD_SV_JSON == vtype) {
+        rv = md_acme_acct_from_json(&acct, (md_json_t*)value, ptemp);
+        if (APR_SUCCESS != rv) goto cleanup;
+
+        if (MD_ACME_ACCT_ST_VALID == acct->status
+            && (!ctx->md || md_acme_acct_matches_md(acct, ctx->md))) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, ctx->p, 
+                          "found account %s for %s: %s, status=%d",
+                          acct->id, ctx->md->ca_effective, aspect, acct->status);
+            ctx->id = apr_pstrdup(ctx->p, name);
+            return 0;
+        }
+    }
+cleanup:
+    return 1;
+}
+
+static apr_status_t acct_find(const char **pid, md_acme_acct_t **pacct, md_pkey_t **ppkey, 
+                              md_store_t *store, md_store_group_t group,
+                              const char *name_pattern,
+                              const md_t *md, apr_pool_t *p)
+{
+    apr_status_t rv;
+    find_ctx ctx;
+
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.p = p;
+    ctx.md = md;
+
+    rv = md_store_iter(find_acct, &ctx, store, p, group, name_pattern, MD_FN_ACCOUNT, MD_SV_JSON);
+    if (ctx.id) {
+        *pid = ctx.id;
+        rv = md_acme_acct_load(pacct, ppkey, store, group, ctx.id, p);
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "acct_find: got account %s", ctx.id);
+    }
+    else {
+        *pacct = NULL;
+        rv = APR_ENOENT;
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, p, "acct_find: none found"); 
+    }
+    return rv;
+}
+
+static apr_status_t acct_find_and_verify(md_store_t *store, md_store_group_t group, 
+                                         const char *name_pattern,
+                                         md_acme_t *acme, const md_t *md,
+                                         apr_pool_t *p)
+{
+    md_acme_acct_t *acct;
+    md_pkey_t *pkey;
+    const char *id;
+    apr_status_t rv;
+
+    rv = acct_find(&id, &acct, &pkey, store, group, name_pattern, md, p);
+    if (APR_SUCCESS == rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, p, "acct_find_and_verify: found %s",
+                      id);
+        acme->acct_id = (MD_SG_STAGING == group)? NULL : id;
+        acme->acct = acct;
+        acme->acct_key = pkey;
+        rv = md_acme_acct_validate(acme, (MD_SG_STAGING == group)? NULL : store, p);
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, p, "acct_find_and_verify: verified %s",
+                      id);
+
+        if (APR_SUCCESS != rv) {
+            acme->acct_id = NULL;
+            acme->acct = NULL;
+            acme->acct_key = NULL;
+            if (APR_STATUS_IS_ENOENT(rv)) {
+                /* verification failed and account has been disabled.
+                   Indicate to caller that he may try again. */
+                rv = APR_EAGAIN;
+            }
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_acme_find_acct_for_md(md_acme_t *acme, md_store_t *store, const md_t *md)
+{
+    apr_status_t rv;
+    
+    while (APR_EAGAIN == (rv = acct_find_and_verify(store, MD_SG_ACCOUNTS, 
+                                                    mk_acct_pattern(acme->p, acme), 
+                                                    acme, md, acme->p))) {
+        /* nop */
+    }
+    
+    if (APR_STATUS_IS_ENOENT(rv)) {
+        /* No suitable account found in MD_SG_ACCOUNTS. Maybe a new account
+         * can already be found in MD_SG_STAGING? */
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, acme->p, 
+                      "no account found, looking in STAGING");
+        rv = acct_find_and_verify(store, MD_SG_STAGING, "*", acme, md, acme->p);
+        if (APR_EAGAIN == rv) {
+            rv = APR_ENOENT;
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_acme_acct_id_for_md(const char **pid, md_store_t *store,
+                                    md_store_group_t group, const md_t *md,
+                                    apr_pool_t *p)
+{
+    apr_status_t rv;
+    find_ctx ctx;
+
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.p = p;
+    ctx.md = md;
+
+    rv = md_store_iter(find_acct, &ctx, store, p, group, "*", MD_FN_ACCOUNT, MD_SV_JSON);
+    if (ctx.id) {
+        *pid = ctx.id;
+        rv = APR_SUCCESS;
+    }
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "acct_id_for_md %s -> %s", md->name, *pid);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* acct operation context */
+typedef struct {
+    md_acme_t *acme;
+    apr_pool_t *p;
+    const char *agreement;
+    const char *eab_kid;
+    const char *eab_hmac;
+} acct_ctx_t;
+
+/**************************************************************************************************/
+/* acct update */
+
+static apr_status_t on_init_acct_upd(md_acme_req_t *req, void *baton)
+{
+    (void)baton;
+    return md_acme_req_body_init(req, NULL);
+} 
+
+static apr_status_t acct_upd(md_acme_t *acme, apr_pool_t *p, 
+                             const apr_table_t *hdrs, md_json_t *body, void *baton)
+{
+    acct_ctx_t *ctx = baton;
+    apr_status_t rv = APR_SUCCESS;
+    md_acme_acct_t *acct = acme->acct;
+
+    if (md_log_is_level(p, MD_LOG_TRACE2)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, acme->p, "acct update response: %s",
+                      md_json_writep(body, p, MD_JSON_FMT_COMPACT));
+    }
+
+    if (!acct->url) {
+        const char *location = apr_table_get(hdrs, "location");
+        if (!location) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, APR_EINVAL, p, "new acct without location");
+            return APR_EINVAL;
+        }
+        acct->url = apr_pstrdup(ctx->p, location);
+    }
+    
+    apr_array_clear(acct->contacts);
+    md_json_dupsa(acct->contacts, acme->p, body, MD_KEY_CONTACT, NULL);
+    if (md_json_has_key(body, MD_KEY_STATUS, NULL)) {
+        acct->status = acct_st_from_str(md_json_gets(body, MD_KEY_STATUS, NULL));
+    }
+    if (md_json_has_key(body, MD_KEY_AGREEMENT, NULL)) {
+        acct->agreement = md_json_dups(acme->p, body, MD_KEY_AGREEMENT, NULL);
+    }
+    if (md_json_has_key(body, MD_KEY_ORDERS, NULL)) {
+        acct->orders = md_json_dups(acme->p, body, MD_KEY_ORDERS, NULL);
+    }
+    if (ctx->eab_kid && ctx->eab_hmac) {
+        acct->eab_kid = ctx->eab_kid;
+        acct->eab_hmac = ctx->eab_hmac;
+    }
+    acct->registration = md_json_clone(ctx->p, body);
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "updated acct %s", acct->url);
+    return rv;
+}
+
+apr_status_t md_acme_acct_update(md_acme_t *acme)
+{
+    acct_ctx_t ctx;
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, acme->p, "acct update");
+    if (!acme->acct) {
+        return APR_EINVAL;
+    }
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.acme = acme;
+    ctx.p = acme->p;
+    return md_acme_POST(acme, acme->acct->url, on_init_acct_upd, acct_upd, NULL, NULL, &ctx);
+}
+
+apr_status_t md_acme_acct_validate(md_acme_t *acme, md_store_t *store, apr_pool_t *p)
+{
+    apr_status_t rv;
+    
+    if (APR_SUCCESS != (rv = md_acme_acct_update(acme))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, acme->p,
+                      "acct update failed for %s", acme->acct->url);
+        if (APR_EINVAL == rv && (acme->acct->agreement || !acme->ca_agreement)) {
+            /* Sadly, some proprietary ACME servers choke on empty POSTs
+             * on accounts. Try a faked ToS agreement. */
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, acme->p,
+                          "trying acct update via ToS agreement");
+            rv = md_acme_agree(acme, p, "accepted");
+        }
+        if (acme->acct && (APR_ENOENT == rv || APR_EACCES == rv || APR_EINVAL == rv)) {
+            if (MD_ACME_ACCT_ST_VALID == acme->acct->status) {
+                acme->acct->status = MD_ACME_ACCT_ST_UNKNOWN;
+                if (store) {
+                    md_acme_acct_save(store, p, acme, &acme->acct_id, acme->acct, acme->acct_key); 
+                }
+            }
+            acme->acct = NULL;
+            acme->acct_key = NULL;
+            rv = APR_ENOENT;
+        }
+    }
+    return rv;
+}
+
+/**************************************************************************************************/
+/* Register a new account */
+
+static apr_status_t get_eab(md_json_t **peab, md_acme_req_t *req, const char *kid,
+                            const char *hmac64, md_pkey_t *account_key,
+                            const char *url)
+{
+    md_json_t *eab, *prot_fields, *jwk;
+    md_data_t payload, hmac_key;
+    apr_status_t rv;
+
+    prot_fields = md_json_create(req->p);
+    md_json_sets(url, prot_fields, "url", NULL);
+    md_json_sets(kid, prot_fields, "kid", NULL);
+
+    rv = md_jws_get_jwk(&jwk, req->p, account_key);
+    if (APR_SUCCESS != rv) goto cleanup;
+
+    md_data_null(&payload);
+    payload.data = md_json_writep(jwk, req->p, MD_JSON_FMT_COMPACT);
+    if (!payload.data) {
+        rv = APR_EINVAL;
+        goto cleanup;
+    }
+    payload.len = strlen(payload.data);
+
+    md_util_base64url_decode(&hmac_key, hmac64, req->p);
+    if (!hmac_key.len) {
+        rv = APR_EINVAL;
+        md_result_problem_set(req->result, rv, "apache:eab-hmac-invalid",
+                              "external account binding HMAC value is not valid base64", NULL);
+        goto cleanup;
+    }
+
+    rv = md_jws_hmac(&eab, req->p, &payload, prot_fields, &hmac_key);
+    if (APR_SUCCESS != rv) {
+        md_result_problem_set(req->result, rv, "apache:eab-hmac-fail",
+                              "external account binding MAC could not be computed", NULL);
+    }
+
+cleanup:
+    *peab = (APR_SUCCESS == rv)? eab : NULL;
+    return rv;
+}
+
+static apr_status_t on_init_acct_new(md_acme_req_t *req, void *baton)
+{
+    acct_ctx_t *ctx = baton;
+    md_json_t *jpayload, *jeab;
+    apr_status_t rv;
+
+    jpayload = md_json_create(req->p);
+    md_json_setsa(ctx->acme->acct->contacts, jpayload, MD_KEY_CONTACT, NULL);
+    if (ctx->agreement) {
+        md_json_setb(1, jpayload, "termsOfServiceAgreed", NULL);
+    }
+    if (ctx->eab_kid && ctx->eab_hmac) {
+        rv = get_eab(&jeab, req, ctx->eab_kid, ctx->eab_hmac,
+                     req->acme->acct_key, req->url);
+        if (APR_SUCCESS != rv) goto cleanup;
+        md_json_setj(jeab, jpayload, "externalAccountBinding", NULL);
+    }
+    rv = md_acme_req_body_init(req, jpayload);
+
+cleanup:
+    return rv;
+} 
+
+apr_status_t md_acme_acct_register(md_acme_t *acme, md_store_t *store,
+                                   const md_t *md, apr_pool_t *p)
+{
+    apr_status_t rv;
+    md_pkey_t *pkey;
+    const char *err = NULL, *uri;
+    md_pkey_spec_t spec;
+    int i;
+    acct_ctx_t ctx;
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, "create new account");
+
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.acme = acme;
+    ctx.p = p;
+    /* The agreement URL is submitted when the ACME server announces Terms-of-Service
+     * in its directory meta data. The magic value "accepted" will always use the
+     * advertised URL. */
+    ctx.agreement = NULL;
+    if (acme->ca_agreement && md->ca_agreement) {
+        ctx.agreement = !strcmp("accepted", md->ca_agreement)?
+            acme->ca_agreement : md->ca_agreement;
+    }
+    
+    if (ctx.agreement) {
+        if (APR_SUCCESS != (rv = md_util_abs_uri_check(acme->p, ctx.agreement, &err))) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, 
+                          "invalid agreement uri (%s): %s", err, ctx.agreement);
+            goto out;
+        }
+    }
+    ctx.eab_kid = md->ca_eab_kid;
+    ctx.eab_hmac = md->ca_eab_hmac;
+    
+    for (i = 0; i < md->contacts->nelts; ++i) {
+        uri = APR_ARRAY_IDX(md->contacts, i, const char *);
+        if (APR_SUCCESS != (rv = md_util_abs_uri_check(acme->p, uri, &err))) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, 
+                          "invalid contact uri (%s): %s", err, uri);
+            goto out;
+        }
+    }
+    
+    /* If there is no key selected yet, try to find an existing one for the same host. 
+     * Let's Encrypt identifies accounts by their key for their ACMEv1 and v2 services.
+     * Although the account appears on both services with different urls, it is 
+     * internally the same one.
+     * I think this is beneficial if someone migrates from ACMEv1 to v2 and not a leak
+     * of identifying information.
+     */
+    if (!acme->acct_key) {
+        find_ctx fctx;
+
+        memset(&fctx, 0, sizeof(fctx));
+        fctx.p = p;
+        fctx.md = md;
+
+        md_store_iter(find_acct, &fctx, store, p, MD_SG_ACCOUNTS, 
+                      mk_acct_pattern(p, acme), MD_FN_ACCOUNT, MD_SV_JSON);
+        if (fctx.id) {
+            rv = md_store_load(store, MD_SG_ACCOUNTS, fctx.id, MD_FN_ACCT_KEY, MD_SV_PKEY,
+                               (void**)&acme->acct_key, p);
+            if (APR_SUCCESS == rv) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p,
+                              "reusing key from account %s", fctx.id);
+            }
+            else {
+                acme->acct_key = NULL;
+            }
+        }
+    }
+    
+    /* If we still have no key, generate a new one */
+    if (!acme->acct_key) {
+        spec.type = MD_PKEY_TYPE_RSA;
+        spec.params.rsa.bits = MD_ACME_ACCT_PKEY_BITS;
+        
+        if (APR_SUCCESS != (rv = md_pkey_gen(&pkey, acme->p, &spec))) goto out;
+        acme->acct_key = pkey;
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "created new account key");
+    }
+    
+    if (APR_SUCCESS != (rv = acct_make(&acme->acct,  p, acme->url, md->contacts))) goto out;
+    rv = md_acme_POST_new_account(acme,  on_init_acct_new, acct_upd, NULL, NULL, &ctx);
+    if (APR_SUCCESS == rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_INFO, 0, p, 
+                      "registered new account %s", acme->acct->url);
+    }
+
+out:    
+    if (APR_SUCCESS != rv && acme->acct) {
+        acme->acct = NULL;
+    }
+    return rv;
+}
+
+/**************************************************************************************************/
+/* Deactivate the account */
+
+static apr_status_t on_init_acct_del(md_acme_req_t *req, void *baton)
+{
+    md_json_t *jpayload;
+
+    (void)baton;
+    jpayload = md_json_create(req->p);
+    md_json_sets("deactivated", jpayload, MD_KEY_STATUS, NULL);
+    return md_acme_req_body_init(req, jpayload);
+} 
+
+apr_status_t md_acme_acct_deactivate(md_acme_t *acme, apr_pool_t *p)
+{
+    md_acme_acct_t *acct = acme->acct;
+    acct_ctx_t ctx;
+    
+    (void)p;
+    if (!acct) {
+        return APR_EINVAL;
+    }
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, acme->p, "delete account %s from %s", 
+                  acct->url, acct->ca_url);
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.acme = acme;
+    ctx.p = p;
+    return md_acme_POST(acme, acct->url, on_init_acct_del, acct_upd, NULL, NULL, &ctx);
+}
+
+/**************************************************************************************************/
+/* terms-of-service */
+
+static apr_status_t on_init_agree_tos(md_acme_req_t *req, void *baton)
+{
+    acct_ctx_t *ctx = baton;
+    md_json_t *jpayload;
+
+    jpayload = md_json_create(req->p);
+    if (ctx->acme->acct->agreement) {
+        md_json_setb(1, jpayload, "termsOfServiceAgreed", NULL);
+    }
+    return md_acme_req_body_init(req, jpayload);
+} 
+
+apr_status_t md_acme_agree(md_acme_t *acme, apr_pool_t *p, const char *agreement)
+{
+    acct_ctx_t ctx;
+    
+    acme->acct->agreement = agreement;
+    if (!strcmp("accepted", agreement) && acme->ca_agreement) {
+        acme->acct->agreement = acme->ca_agreement;
+    }
+    
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.acme = acme;
+    ctx.p = p;
+    return md_acme_POST(acme, acme->acct->url, on_init_agree_tos, acct_upd, NULL, NULL, &ctx);
+}
+
+apr_status_t md_acme_check_agreement(md_acme_t *acme, apr_pool_t *p, 
+                                     const char *agreement, const char **prequired)
+{
+    apr_status_t rv = APR_SUCCESS;
+    
+    /* We used to really check if the account agreement and the one indicated in meta
+     * are the very same. However, LE is happy if the account has agreed to a ToS in 
+     * the past and does not require a renewed acceptance.
+     */
+    *prequired = NULL;
+    if (!acme->acct->agreement && acme->ca_agreement) {
+        if (agreement) {
+            rv = md_acme_agree(acme, p, acme->ca_agreement);
+        }
+        else {
+            *prequired = acme->ca_agreement;
+            rv = APR_INCOMPLETE;
+        }
+    }
+    return rv;
+}        
diff --git a/modules/md/md_acme_acct.h b/modules/md/md_acme_acct.h
new file mode 100644
index 0000000..b5bba63
--- /dev/null
+++ b/modules/md/md_acme_acct.h
@@ -0,0 +1,148 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_acme_acct_h
+#define mod_md_md_acme_acct_h
+
+struct md_acme_req;
+struct md_json_t;
+struct md_pkey_t;
+
+#include "md_store.h"
+
+/** 
+ * An ACME account at an ACME server.
+ */
+typedef struct md_acme_acct_t md_acme_acct_t;
+
+typedef enum {
+    MD_ACME_ACCT_ST_UNKNOWN,
+    MD_ACME_ACCT_ST_VALID,
+    MD_ACME_ACCT_ST_DEACTIVATED,
+    MD_ACME_ACCT_ST_REVOKED,
+} md_acme_acct_st;
+
+struct md_acme_acct_t {
+    const char *id;                 /* short, unique id for the account */
+    const char *url;                /* url of the account, once registered */
+    const char *ca_url;             /* url of the ACME protocol endpoint */
+    md_acme_acct_st status;         /* status of this account */
+    apr_array_header_t *contacts;   /* list of contact uris, e.g. mailto:xxx */
+    const char *tos_required;       /* terms of service asked for by CA */
+    const char *agreement;          /* terms of service agreed to by user */
+    const char *orders;             /* URL where certificate orders are found (ACMEv2) */
+    const char *eab_kid;            /* external account binding keyid used or NULL */
+    const char *eab_hmac;           /* external account binding hmac used or NULL */
+    struct md_json_t *registration; /* data from server registration */
+};
+
+#define MD_FN_ACCOUNT           "account.json"
+#define MD_FN_ACCT_KEY          "account.pem"
+
+/* ACME account private keys are always RSA and have that many bits. Since accounts
+ * are expected to live long, better err on the safe side. */
+#define MD_ACME_ACCT_PKEY_BITS  3072
+
+#define MD_ACME_ACCT_STAGED     "staged"
+
+/**
+ * Convert an ACME account form/to JSON.
+ */
+struct md_json_t *md_acme_acct_to_json(md_acme_acct_t *acct, apr_pool_t *p);
+apr_status_t md_acme_acct_from_json(md_acme_acct_t **pacct, struct md_json_t *json, apr_pool_t *p);
+
+/**
+ * Update the account from the ACME server.
+ * - Will update acme->acct structure from server on success
+ * - Will return error status when request failed or account is not known.
+ */
+apr_status_t md_acme_acct_update(md_acme_t *acme);
+
+/**
+ * Update the account and persist changes in the store, if given (and not NULL).
+ */
+apr_status_t md_acme_acct_validate(md_acme_t *acme, md_store_t *store, apr_pool_t *p);
+
+/**
+ * Agree to the given Terms-of-Service url for the current account.
+ */
+apr_status_t md_acme_agree(md_acme_t *acme, apr_pool_t *p, const char *tos);
+
+/**
+ * Confirm with the server that the current account agrees to the Terms-of-Service
+ * given in the agreement url.
+ * If the known agreement is equal to this, nothing is done.
+ * If it differs, the account is re-validated in the hope that the server
+ * announces the Tos URL it wants. If this is equal to the agreement specified,
+ * the server is notified of this. If the server requires a ToS that the account
+ * thinks it has already given, it is resend.
+ *
+ * If an agreement is required, different from the current one, APR_INCOMPLETE is
+ * returned and the agreement url is returned in the parameter.
+ */
+apr_status_t md_acme_check_agreement(md_acme_t *acme, apr_pool_t *p, 
+                                     const char *agreement, const char **prequired);
+
+/**
+ * Get the ToS agreement for current account.
+ */
+const char *md_acme_get_agreement(md_acme_t *acme);
+
+
+/** 
+ * Find an existing account in the local store. On APR_SUCCESS, the acme
+ * instance will have a current, validated account to use.
+ */ 
+apr_status_t md_acme_find_acct_for_md(md_acme_t *acme, md_store_t *store, const md_t *md);
+
+/**
+ * Find the account id for a given md.
+ */
+apr_status_t md_acme_acct_id_for_md(const char **pid, md_store_t *store,
+                                    md_store_group_t group, const md_t *md, apr_pool_t *p);
+
+/**
+ * Create a new account at the ACME server for an MD. The
+ * new account is the one used by the acme instance afterwards, on success.
+ */
+apr_status_t md_acme_acct_register(md_acme_t *acme, md_store_t *store, 
+                                   const md_t *md, apr_pool_t *p);
+
+apr_status_t md_acme_acct_save(md_store_t *store, apr_pool_t *p, md_acme_t *acme,  
+                               const char **pid, struct md_acme_acct_t *acct, 
+                               struct md_pkey_t *acct_key);
+                               
+/**
+ * Deactivate the current account at the ACME server. 
+ */
+apr_status_t md_acme_acct_deactivate(md_acme_t *acme, apr_pool_t *p);
+
+apr_status_t md_acme_acct_load(struct md_acme_acct_t **pacct, struct md_pkey_t **ppkey,
+                               md_store_t *store, md_store_group_t group, 
+                               const char *name, apr_pool_t *p);
+
+/*
+ * Return != 0 iff the account can be used for the ACME url.
+ */
+int md_acme_acct_matches_url(md_acme_acct_t *acct, const char *url);
+
+/*
+ * Return != 0 iff the account can be used for the MD, including
+ * its CA url and EAB settings.
+ */
+int md_acme_acct_matches_md(md_acme_acct_t *acct, const md_t *md);
+
+#endif /* md_acme_acct_h */
diff --git a/modules/md/md_acme_authz.c b/modules/md/md_acme_authz.c
new file mode 100644
index 0000000..a55804e
--- /dev/null
+++ b/modules/md/md_acme_authz.c
@@ -0,0 +1,697 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stdio.h>
+
+#include <apr_lib.h>
+#include <apr_buckets.h>
+#include <apr_file_info.h>
+#include <apr_file_io.h>
+#include <apr_fnmatch.h>
+#include <apr_hash.h>
+#include <apr_strings.h>
+#include <apr_tables.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_http.h"
+#include "md_log.h"
+#include "md_jws.h"
+#include "md_result.h"
+#include "md_store.h"
+#include "md_util.h"
+
+#include "md_acme.h"
+#include "md_acme_authz.h"
+
+md_acme_authz_t *md_acme_authz_create(apr_pool_t *p)
+{
+    md_acme_authz_t *authz;
+    authz = apr_pcalloc(p, sizeof(*authz));
+    
+    return authz;
+}
+
+/**************************************************************************************************/
+/* Register a new authorization */
+
+typedef struct {
+    size_t index;
+    const char *type;
+    const char *uri;
+    const char *token;
+    const char *key_authz;
+} md_acme_authz_cha_t;
+
+typedef struct {
+    apr_pool_t *p;
+    md_acme_t *acme;
+    const char *domain;
+    md_acme_authz_t *authz;
+    md_acme_authz_cha_t *challenge;
+} authz_req_ctx;
+
+static void authz_req_ctx_init(authz_req_ctx *ctx, md_acme_t *acme, 
+                               const char *domain, md_acme_authz_t *authz, apr_pool_t *p)
+{
+    memset(ctx, 0, sizeof(*ctx));
+    ctx->p = p;
+    ctx->acme = acme;
+    ctx->domain = domain;
+    ctx->authz = authz;
+}
+
+/**************************************************************************************************/
+/* Update an existing authorization */
+
+apr_status_t md_acme_authz_retrieve(md_acme_t *acme, apr_pool_t *p, const char *url, 
+                                    md_acme_authz_t **pauthz)
+{
+    md_acme_authz_t *authz;
+    apr_status_t rv;
+    
+    authz = apr_pcalloc(p, sizeof(*authz));
+    authz->url = apr_pstrdup(p, url);
+    rv = md_acme_authz_update(authz, acme, p);
+    
+    *pauthz = (APR_SUCCESS == rv)? authz : NULL;
+    return rv;
+}
+
+typedef struct {
+    apr_pool_t *p;
+    md_acme_authz_t *authz;
+} error_ctx_t;
+
+static int copy_challenge_error(void *baton, size_t index, md_json_t *json)
+{
+    error_ctx_t *ctx = baton;
+    
+    (void)index;
+    if (md_json_has_key(json, MD_KEY_ERROR, NULL)) {
+        ctx->authz->error_type = md_json_dups(ctx->p, json, MD_KEY_ERROR, MD_KEY_TYPE, NULL);
+        ctx->authz->error_detail = md_json_dups(ctx->p, json, MD_KEY_ERROR, MD_KEY_DETAIL, NULL);
+        ctx->authz->error_subproblems = md_json_dupj(ctx->p, json, MD_KEY_ERROR, MD_KEY_SUBPROBLEMS, NULL);
+    }
+    return 1;
+}
+
+apr_status_t md_acme_authz_update(md_acme_authz_t *authz, md_acme_t *acme, apr_pool_t *p)
+{
+    md_json_t *json;
+    const char *s, *err;
+    md_log_level_t log_level;
+    apr_status_t rv;
+    error_ctx_t ctx;
+    
+    assert(acme);
+    assert(acme->http);
+    assert(authz);
+    assert(authz->url);
+
+    authz->state = MD_ACME_AUTHZ_S_UNKNOWN;
+    json = NULL;
+    authz->error_type = authz->error_detail = NULL;
+    authz->error_subproblems = NULL;
+    err = "unable to parse response";
+    log_level = MD_LOG_ERR;
+    
+    if (APR_SUCCESS == (rv = md_acme_get_json(&json, acme, authz->url, p))
+        && (s = md_json_gets(json, MD_KEY_STATUS, NULL))) {
+            
+        authz->domain = md_json_gets(json, MD_KEY_IDENTIFIER, MD_KEY_VALUE, NULL); 
+        authz->resource = json;
+        if (!strcmp(s, "pending")) {
+            authz->state = MD_ACME_AUTHZ_S_PENDING;
+            err = "challenge 'pending'";
+            log_level = MD_LOG_DEBUG;
+        }
+        else if (!strcmp(s, "valid")) {
+            authz->state = MD_ACME_AUTHZ_S_VALID;
+            err = "challenge 'valid'";
+            log_level = MD_LOG_DEBUG;
+        }
+        else if (!strcmp(s, "invalid")) {
+            ctx.p = p;
+            ctx.authz = authz;
+            authz->state = MD_ACME_AUTHZ_S_INVALID;
+            md_json_itera(copy_challenge_error, &ctx, json, MD_KEY_CHALLENGES, NULL);
+            err = "challenge 'invalid'";
+        }
+    }
+
+    if (json && authz->state == MD_ACME_AUTHZ_S_UNKNOWN) {
+        err = "unable to understand response";
+        rv = APR_EINVAL;
+    }
+    
+    if (md_log_is_level(p, log_level)) {
+        md_log_perror(MD_LOG_MARK, log_level, rv, p, "ACME server authz: %s for %s at %s. "
+                      "Exact response was: %s", err, authz->domain, authz->url,
+                      json? md_json_writep(json, p, MD_JSON_FMT_COMPACT) : "not available");
+    }
+    
+    return rv;
+}
+
+/**************************************************************************************************/
+/* response to a challenge */
+
+static md_acme_authz_cha_t *cha_from_json(apr_pool_t *p, size_t index, md_json_t *json)
+{
+    md_acme_authz_cha_t * cha;
+    
+    cha = apr_pcalloc(p, sizeof(*cha));
+    cha->index = index;
+    cha->type = md_json_dups(p, json, MD_KEY_TYPE, NULL);
+    if (md_json_has_key(json, MD_KEY_URL, NULL)) { /* ACMEv2 */
+        cha->uri = md_json_dups(p, json, MD_KEY_URL, NULL);
+    }
+    else {                                         /* ACMEv1 */
+        cha->uri = md_json_dups(p, json, MD_KEY_URI, NULL);
+    }
+    cha->token = md_json_dups(p, json, MD_KEY_TOKEN, NULL);
+    cha->key_authz = md_json_dups(p, json, MD_KEY_KEYAUTHZ, NULL);
+
+    return cha;
+}
+
+static apr_status_t on_init_authz_resp(md_acme_req_t *req, void *baton)
+{
+    md_json_t *jpayload;
+
+    (void)baton;
+    jpayload = md_json_create(req->p);
+    return md_acme_req_body_init(req, jpayload);
+} 
+
+static apr_status_t authz_http_set(md_acme_t *acme, apr_pool_t *p, const apr_table_t *hdrs, 
+                                   md_json_t *body, void *baton)
+{
+    authz_req_ctx *ctx = baton;
+    
+    (void)acme;
+    (void)p;
+    (void)hdrs;
+    (void)body;
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ctx->p, "updated authz %s", ctx->authz->url);
+    return APR_SUCCESS;
+}
+
+static apr_status_t setup_key_authz(md_acme_authz_cha_t *cha, md_acme_authz_t *authz,
+                                    md_acme_t *acme, apr_pool_t *p, int *pchanged)
+{
+    const char *thumb64, *key_authz;
+    apr_status_t rv;
+    
+    (void)authz;
+    assert(cha);
+    assert(cha->token);
+    
+    *pchanged = 0;
+    if (APR_SUCCESS == (rv = md_jws_pkey_thumb(&thumb64, p, acme->acct_key))) {
+        key_authz = apr_psprintf(p, "%s.%s", cha->token, thumb64);
+        if (cha->key_authz) {
+            if (strcmp(key_authz, cha->key_authz)) {
+                /* Hu? Did the account change key? */
+                cha->key_authz = NULL;
+            }
+        }
+        if (!cha->key_authz) {
+            cha->key_authz = key_authz;
+            *pchanged = 1;
+        }
+    }
+    return rv;
+}
+
+static apr_status_t cha_http_01_setup(md_acme_authz_cha_t *cha, md_acme_authz_t *authz,
+                                      md_acme_t *acme, md_store_t *store, 
+                                      md_pkeys_spec_t *key_specs,
+                                      apr_array_header_t *acme_tls_1_domains, const md_t *md,
+                                      apr_table_t *env, md_result_t *result, apr_pool_t *p)
+{
+    const char *data;
+    apr_status_t rv;
+    int notify_server;
+    
+    (void)key_specs;
+    (void)env;
+    (void)acme_tls_1_domains;
+    (void)md;
+
+    if (APR_SUCCESS != (rv = setup_key_authz(cha, authz, acme, p, &notify_server))) {
+        goto out;
+    }
+    
+    rv = md_store_load(store, MD_SG_CHALLENGES, authz->domain, MD_FN_HTTP01,
+                       MD_SV_TEXT, (void**)&data, p);
+    if ((APR_SUCCESS == rv && strcmp(cha->key_authz, data)) || APR_STATUS_IS_ENOENT(rv)) {
+        const char *content = apr_psprintf(p, "%s\n", cha->key_authz);
+        rv = md_store_save(store, p, MD_SG_CHALLENGES, authz->domain, MD_FN_HTTP01,
+                           MD_SV_TEXT, (void*)content, 0);
+        notify_server = 1;
+    }
+    
+    if (APR_SUCCESS == rv && notify_server) {
+        authz_req_ctx ctx;
+        const char *event;
+
+        /* Raise event that challenge data has been set up before we tell the
+           ACME server. Clusters might want to distribute it. */
+        event = apr_psprintf(p, "challenge-setup:%s:%s", MD_AUTHZ_TYPE_HTTP01, authz->domain);
+        rv = md_result_raise(result, event, p);
+        if (APR_SUCCESS != rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p,
+                          "%s: event '%s' failed. aborting challenge setup",
+                          authz->domain, event);
+            goto out;
+        }
+        /* challenge is setup or was changed from previous data, tell ACME server
+         * so it may (re)try verification */        
+        authz_req_ctx_init(&ctx, acme, NULL, authz, p);
+        ctx.challenge = cha;
+        rv = md_acme_POST(acme, cha->uri, on_init_authz_resp, authz_http_set, NULL, NULL, &ctx);
+    }
+out:
+    return rv;
+}
+
+void tls_alpn01_fnames(apr_pool_t *p, md_pkey_spec_t *kspec, char **keyfn, char **certfn )
+{
+    *keyfn  = apr_pstrcat(p, "acme-tls-alpn-01-", md_pkey_filename(kspec, p), NULL);
+    *certfn = apr_pstrcat(p, "acme-tls-alpn-01-", md_chain_filename(kspec, p), NULL);
+}
+
+static apr_status_t cha_tls_alpn_01_setup(md_acme_authz_cha_t *cha, md_acme_authz_t *authz, 
+                                          md_acme_t *acme, md_store_t *store, 
+                                          md_pkeys_spec_t *key_specs,
+                                          apr_array_header_t *acme_tls_1_domains, const md_t *md,
+                                          apr_table_t *env, md_result_t *result, apr_pool_t *p)
+{
+    const char *acme_id, *token;
+    apr_status_t rv;
+    int notify_server;
+    md_data_t data;
+    int i;
+
+    (void)env;
+    (void)md;
+    if (md_array_str_index(acme_tls_1_domains, authz->domain, 0, 0) < 0) {
+        rv = APR_ENOTIMPL;
+        if (acme_tls_1_domains->nelts) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p,
+                          "%s: protocol 'acme-tls/1' seems not enabled for this domain, "
+                          "but is enabled for other associated domains. "
+                          "Continuing with fingers crossed.", authz->domain);
+        }
+        else {
+            md_log_perror(MD_LOG_MARK, MD_LOG_INFO, 0, p,
+                          "%s: protocol 'acme-tls/1' seems not enabled for this or "
+                          "any other associated domain. Not attempting challenge "
+                          "type tls-alpn-01.", authz->domain);
+            goto out;
+        }
+    }
+    if (APR_SUCCESS != (rv = setup_key_authz(cha, authz, acme, p, &notify_server))) {
+        goto out;
+    }
+
+    /* Create a "tls-alpn-01" certificate for the domain we want to authenticate.
+     * The server will need to answer a TLS connection with SNI == authz->domain
+     * and ALPN protocol "acme-tls/1" with this certificate.
+     */
+    md_data_init_str(&data, cha->key_authz);
+    rv = md_crypt_sha256_digest_hex(&token, p, &data);
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: create tls-alpn-01 validation token",
+                      authz->domain);
+        goto out;
+    }
+    acme_id = apr_psprintf(p, "critical,DER:04:20:%s", token);
+
+    /* Each configured key type must be generated to ensure:
+     * that any fallback certs already given to mod_ssl are replaced.
+     * We expect that the validation client (at the CA) can deal with at
+     * least one of them.
+     */
+
+    for (i = 0; i < md_pkeys_spec_count(key_specs); ++i) {
+        char *kfn, *cfn;
+        md_cert_t *cha_cert;
+        md_pkey_t *cha_key;
+        md_pkey_spec_t *key_spec;
+
+        key_spec = md_pkeys_spec_get(key_specs, i);
+        tls_alpn01_fnames(p, key_spec, &kfn, &cfn);
+
+        rv = md_store_load(store, MD_SG_CHALLENGES, authz->domain, cfn,
+                           MD_SV_CERT, (void**)&cha_cert, p);
+        if ((APR_SUCCESS == rv && !md_cert_covers_domain(cha_cert, authz->domain))
+            || APR_STATUS_IS_ENOENT(rv)) {
+            if (APR_SUCCESS != (rv = md_pkey_gen(&cha_key, p, key_spec))) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: create tls-alpn-01 %s challenge key",
+                              authz->domain, md_pkey_spec_name(key_spec));
+                goto out;
+            }
+
+            if (APR_SUCCESS != (rv = md_cert_make_tls_alpn_01(&cha_cert, authz->domain, acme_id, cha_key,
+                                                              apr_time_from_sec(7 * MD_SECS_PER_DAY), p))) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: create tls-alpn-01 %s challenge cert",
+                              authz->domain, md_pkey_spec_name(key_spec));
+                goto out;
+            }
+        
+            if (APR_SUCCESS == (rv = md_store_save(store, p, MD_SG_CHALLENGES, authz->domain, kfn,
+                                                   MD_SV_PKEY, (void*)cha_key, 0))) {
+                rv = md_store_save(store, p, MD_SG_CHALLENGES, authz->domain, cfn,
+                                   MD_SV_CERT, (void*)cha_cert, 0);
+            }
+            ++notify_server;
+        }
+    }
+    
+    if (APR_SUCCESS == rv && notify_server) {
+        authz_req_ctx ctx;
+        const char *event;
+
+        /* Raise event that challenge data has been set up before we tell the
+           ACME server. Clusters might want to distribute it. */
+        event = apr_psprintf(p, "challenge-setup:%s:%s", MD_AUTHZ_TYPE_TLSALPN01, authz->domain);
+        rv = md_result_raise(result, event, p);
+        if (APR_SUCCESS != rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p,
+                          "%s: event '%s' failed. aborting challenge setup",
+                          authz->domain, event);
+            goto out;
+        }
+        /* challenge is setup or was changed from previous data, tell ACME server
+         * so it may (re)try verification */        
+        authz_req_ctx_init(&ctx, acme, NULL, authz, p);
+        ctx.challenge = cha;
+        rv = md_acme_POST(acme, cha->uri, on_init_authz_resp, authz_http_set, NULL, NULL, &ctx);
+    }
+out:    
+    return rv;
+}
+
+static apr_status_t cha_dns_01_setup(md_acme_authz_cha_t *cha, md_acme_authz_t *authz, 
+                                     md_acme_t *acme, md_store_t *store, 
+                                     md_pkeys_spec_t *key_specs,
+                                     apr_array_header_t *acme_tls_1_domains, const md_t *md,
+                                     apr_table_t *env, md_result_t *result, apr_pool_t *p)
+{
+    const char *token;
+    const char * const *argv;
+    const char *cmdline, *dns01_cmd;
+    apr_status_t rv;
+    int exit_code, notify_server;
+    authz_req_ctx ctx;
+    md_data_t data;
+    const char *event;
+
+    (void)store;
+    (void)key_specs;
+    (void)acme_tls_1_domains;
+
+    dns01_cmd = md->dns01_cmd;
+    if (!dns01_cmd)
+      dns01_cmd = apr_table_get(env, MD_KEY_CMD_DNS01);
+    if (!dns01_cmd) {
+        rv = APR_ENOTIMPL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "%s: dns-01 command not set", 
+                      authz->domain);
+        goto out;
+    }
+    
+    if (APR_SUCCESS != (rv = setup_key_authz(cha, authz, acme, p, &notify_server))) {
+        goto out;
+    }
+    
+    md_data_init_str(&data, cha->key_authz);
+    rv = md_crypt_sha256_digest64(&token, p, &data);
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: create dns-01 token for %s",
+                      md->name, authz->domain);
+        goto out;
+    }
+
+    cmdline = apr_psprintf(p, "%s setup %s %s", dns01_cmd, authz->domain, token); 
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, 
+                  "%s: dns-01 setup command: %s", authz->domain, cmdline);
+
+    apr_tokenize_to_argv(cmdline, (char***)&argv, p);
+    if (APR_SUCCESS != (rv = md_util_exec(p, argv[0], argv, NULL, &exit_code))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, p, 
+                      "%s: dns-01 setup command failed to execute for %s", md->name, authz->domain);
+        goto out;
+    }
+    if (exit_code) {
+        rv = APR_EGENERAL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_INFO, rv, p, 
+                      "%s: dns-01 setup command returns %d for %s", md->name, exit_code, authz->domain);
+        goto out;
+    }
+    
+    /* Raise event that challenge data has been set up before we tell the
+       ACME server. Clusters might want to distribute it. */
+    event = apr_psprintf(p, "challenge-setup:%s:%s", MD_AUTHZ_TYPE_DNS01, authz->domain);
+    rv = md_result_raise(result, event, p);
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p,
+                      "%s: event '%s' failed. aborting challenge setup",
+                      authz->domain, event);
+        goto out;
+    }
+    /* challenge is setup, tell ACME server so it may (re)try verification */
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "%s: dns-01 setup succeeded for %s",
+       md->name, authz->domain);
+    authz_req_ctx_init(&ctx, acme, NULL, authz, p);
+    ctx.challenge = cha;
+    rv = md_acme_POST(acme, cha->uri, on_init_authz_resp, authz_http_set, NULL, NULL, &ctx);
+    
+out:    
+    return rv;
+}
+
+static apr_status_t cha_dns_01_teardown(md_store_t *store, const char *domain, const md_t *md,
+                                        apr_table_t *env, apr_pool_t *p)
+{
+    const char * const *argv;
+    const char *cmdline, *dns01_cmd;
+    apr_status_t rv;
+    int exit_code;
+    
+    (void)store;
+
+    dns01_cmd = md->dns01_cmd;
+    if (!dns01_cmd)
+      dns01_cmd = apr_table_get(env, MD_KEY_CMD_DNS01);
+    if (!dns01_cmd) {
+        rv = APR_ENOTIMPL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, "%s: dns-01 command not set for %s",
+            md->name, domain);
+        goto out;
+    }
+    
+    cmdline = apr_psprintf(p, "%s teardown %s", dns01_cmd, domain); 
+    apr_tokenize_to_argv(cmdline, (char***)&argv, p);
+    if (APR_SUCCESS != (rv = md_util_exec(p, argv[0], argv, NULL, &exit_code)) || exit_code) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, p, 
+                      "%s: dns-01 teardown command failed (exit code=%d) for %s",
+                      md->name, exit_code, domain);
+    }
+out:    
+    return rv;
+}
+
+static apr_status_t cha_teardown_dir(md_store_t *store, const char *domain, const md_t *md,
+                                     apr_table_t *env, apr_pool_t *p)
+{
+    (void)md;
+    (void)env;
+    return md_store_purge(store, p, MD_SG_CHALLENGES, domain);
+}
+
+typedef apr_status_t cha_setup(md_acme_authz_cha_t *cha, md_acme_authz_t *authz, 
+                               md_acme_t *acme, md_store_t *store, 
+                               md_pkeys_spec_t *key_specs,
+                               apr_array_header_t *acme_tls_1_domains, const md_t *md,
+                               apr_table_t *env, md_result_t *result, apr_pool_t *p);
+                               
+typedef apr_status_t cha_teardown(md_store_t *store, const char *domain, const md_t *md,
+                                  apr_table_t *env, apr_pool_t *p);
+                                 
+typedef struct {
+    const char *name;
+    cha_setup *setup;
+    cha_teardown *teardown;
+} cha_type;
+
+static const cha_type CHA_TYPES[] = {
+    { MD_AUTHZ_TYPE_HTTP01,     cha_http_01_setup,      cha_teardown_dir },
+    { MD_AUTHZ_TYPE_TLSALPN01,  cha_tls_alpn_01_setup,  cha_teardown_dir },
+    { MD_AUTHZ_TYPE_DNS01,      cha_dns_01_setup,       cha_dns_01_teardown },
+};
+static const apr_size_t CHA_TYPES_LEN = (sizeof(CHA_TYPES)/sizeof(CHA_TYPES[0]));
+
+typedef struct {
+    apr_pool_t *p;
+    const char *type;
+    md_acme_authz_cha_t *accepted;
+    apr_array_header_t *offered;
+} cha_find_ctx;
+
+static apr_status_t collect_offered(void *baton, size_t index, md_json_t *json)
+{
+    cha_find_ctx *ctx = baton;
+    const char *ctype;
+    
+    (void)index;
+    if ((ctype = md_json_gets(json, MD_KEY_TYPE, NULL))) {
+        APR_ARRAY_PUSH(ctx->offered, const char*) = apr_pstrdup(ctx->p, ctype);
+    }
+    return 1;
+}
+
+static apr_status_t find_type(void *baton, size_t index, md_json_t *json)
+{
+    cha_find_ctx *ctx = baton;
+    
+    const char *ctype = md_json_gets(json, MD_KEY_TYPE, NULL);
+    if (ctype && !apr_strnatcasecmp(ctx->type, ctype)) {
+        ctx->accepted = cha_from_json(ctx->p, index, json);
+        return 0;
+    }
+    return 1;
+}
+
+apr_status_t md_acme_authz_respond(md_acme_authz_t *authz, md_acme_t *acme, md_store_t *store, 
+                                   apr_array_header_t *challenges, md_pkeys_spec_t *key_specs,
+                                   apr_array_header_t *acme_tls_1_domains, const md_t *md,
+                                   apr_table_t *env, apr_pool_t *p, const char **psetup_token,
+                                   md_result_t *result)
+{
+    apr_status_t rv;
+    int i, j;
+    cha_find_ctx fctx;
+    const char *challenge_setup;
+    
+    assert(acme);
+    assert(authz);
+    assert(authz->resource);
+
+    fctx.p = p;
+    fctx.accepted = NULL;
+    
+    /* Look in the order challenge types are defined:
+     * - if they are offered by the CA, try to set it up
+     * - if setup was successful, we are done and the CA will evaluate us
+     * - if setup failed, continue to look for another supported challenge type
+     * - if there is no overlap in types, tell the user that she has to configure
+     *   either more types (dns, tls-alpn-01), make ports available or refrain
+     *   from using wildcard domains when dns is not available. etc.
+     * - if there was an overlap, but no setup was successful, report that. We
+     *   will retry this, maybe the failure is temporary (e.g. command to setup DNS
+     */
+     md_result_printf(result, 0, "%s: selecting suitable authorization challenge "
+                      "type, this domain supports %s",
+                      authz->domain, apr_array_pstrcat(p, challenges, ' '));
+    rv = APR_ENOTIMPL;
+    challenge_setup = NULL;
+    for (i = 0; i < challenges->nelts; ++i) {
+        fctx.type = APR_ARRAY_IDX(challenges, i, const char *);
+        fctx.accepted = NULL;
+        md_json_itera(find_type, &fctx, authz->resource, MD_KEY_CHALLENGES, NULL);
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, p,
+                      "%s: challenge type '%s' for %s: %s",
+                      authz->domain, fctx.type, md->name,
+                      fctx.accepted? "maybe acceptable" : "not applicable");
+
+        if (fctx.accepted) {
+            for (j = 0; j < (int)CHA_TYPES_LEN; ++j) {
+                if (!apr_strnatcasecmp(CHA_TYPES[j].name, fctx.accepted->type)) {
+                    md_result_activity_printf(result, "Setting up challenge '%s' for domain %s", 
+                                              fctx.accepted->type, authz->domain);
+                    rv = CHA_TYPES[j].setup(fctx.accepted, authz, acme, store, key_specs,
+                                            acme_tls_1_domains, md, env, result, p);
+                    if (APR_SUCCESS == rv) {
+                        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, 
+                                      "%s: set up challenge '%s' for %s", 
+                                      authz->domain, fctx.accepted->type, md->name);
+                        challenge_setup = CHA_TYPES[j].name;
+                        goto out;
+                    }
+                    md_result_printf(result, rv, "error setting up challenge '%s' for %s, "
+                                     "for domain %s, looking for other option",
+                                     fctx.accepted->type, authz->domain, md->name);
+                    md_result_log(result, MD_LOG_INFO);
+                }
+            }
+        }
+    }
+    
+out:
+    *psetup_token = (APR_SUCCESS == rv)? apr_psprintf(p, "%s:%s", challenge_setup, authz->domain) : NULL;
+    if (!fctx.accepted || APR_ENOTIMPL == rv) {
+        rv = APR_EINVAL;
+        fctx.offered = apr_array_make(p, 5, sizeof(const char*));
+        md_json_itera(collect_offered, &fctx, authz->resource, MD_KEY_CHALLENGES, NULL);
+        md_result_printf(result, rv, "None of offered challenge types for domain %s are supported. "
+                      "The server offered '%s' and available are: '%s'.",
+                      authz->domain, 
+                      apr_array_pstrcat(p, fctx.offered, ' '),
+                      apr_array_pstrcat(p, challenges, ' '));
+        result->problem = "challenge-mismatch";
+        md_result_log(result, MD_LOG_ERR);
+    }
+    else if (APR_SUCCESS != rv) {
+        fctx.offered = apr_array_make(p, 5, sizeof(const char*));
+        md_json_itera(collect_offered, &fctx, authz->resource, MD_KEY_CHALLENGES, NULL);
+        md_result_printf(result, rv, "None of the offered challenge types %s offered "
+                         "for domain %s could be setup successfully. Please check the "
+                         "log for errors.", authz->domain, 
+                         apr_array_pstrcat(p, fctx.offered, ' '));
+        result->problem = "challenge-setup-failure";
+        md_result_log(result, MD_LOG_ERR);
+    }
+    return rv;
+}
+
+apr_status_t md_acme_authz_teardown(struct md_store_t *store, const char *token,
+                                    const md_t *md, apr_table_t *env, apr_pool_t *p)
+{
+    char *challenge, *domain;
+    int i;
+    
+    if (strchr(token, ':')) {
+        challenge = apr_pstrdup(p, token);
+        domain = strchr(challenge, ':');
+        *domain = '\0'; domain++;
+        for (i = 0; i < (int)CHA_TYPES_LEN; ++i) {
+            if (!apr_strnatcasecmp(CHA_TYPES[i].name, challenge)) {
+                if (CHA_TYPES[i].teardown) {
+                    return CHA_TYPES[i].teardown(store, domain, md, env, p);
+                }
+                break;
+            }
+        }
+    }
+    return APR_SUCCESS;
+}
+
diff --git a/modules/md/md_acme_authz.h b/modules/md/md_acme_authz.h
new file mode 100644
index 0000000..d74beeb
--- /dev/null
+++ b/modules/md/md_acme_authz.h
@@ -0,0 +1,79 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_acme_authz_h
+#define mod_md_md_acme_authz_h
+
+struct apr_array_header_t;
+struct apr_table_t;
+struct md_acme_t;
+struct md_acme_acct_t;
+struct md_json_t;
+struct md_store_t;
+struct md_pkey_spec_t;
+struct md_result_t;
+
+typedef struct md_acme_challenge_t md_acme_challenge_t;
+
+/**************************************************************************************************/
+/* authorization request for a specific domain name */
+
+#define MD_AUTHZ_TYPE_DNS01         "dns-01"
+#define MD_AUTHZ_TYPE_HTTP01        "http-01"
+#define MD_AUTHZ_TYPE_TLSALPN01     "tls-alpn-01"
+
+typedef enum {
+    MD_ACME_AUTHZ_S_UNKNOWN,
+    MD_ACME_AUTHZ_S_PENDING,
+    MD_ACME_AUTHZ_S_VALID,
+    MD_ACME_AUTHZ_S_INVALID,
+} md_acme_authz_state_t;
+
+typedef struct md_acme_authz_t md_acme_authz_t;
+
+struct md_acme_authz_t {
+    const char *domain;
+    const char *url;
+    md_acme_authz_state_t state;
+    apr_time_t expires;
+    const char *error_type;
+    const char *error_detail;
+    const struct md_json_t *error_subproblems;
+    struct md_json_t *resource;
+};
+
+#define MD_FN_HTTP01            "acme-http-01.txt"
+
+void tls_alpn01_fnames(apr_pool_t *p, struct md_pkey_spec_t *kspec, char **keyfn, char **certfn );
+
+md_acme_authz_t *md_acme_authz_create(apr_pool_t *p);
+
+apr_status_t md_acme_authz_retrieve(md_acme_t *acme, apr_pool_t *p, const char *url,
+                                    md_acme_authz_t **pauthz);
+apr_status_t md_acme_authz_update(md_acme_authz_t *authz, struct md_acme_t *acme, apr_pool_t *p);
+
+apr_status_t md_acme_authz_respond(md_acme_authz_t *authz, struct md_acme_t *acme, 
+                                   struct md_store_t *store, apr_array_header_t *challenges, 
+                                   struct md_pkeys_spec_t *key_spec,
+                                   apr_array_header_t *acme_tls_1_domains, const md_t *md,
+                                   struct apr_table_t *env,
+                                   apr_pool_t *p, const char **setup_token,
+                                   struct md_result_t *result);
+
+apr_status_t md_acme_authz_teardown(struct md_store_t *store, const char *setup_token, 
+                                    const md_t *md, struct apr_table_t *env, apr_pool_t *p);
+
+#endif /* md_acme_authz_h */
diff --git a/modules/md/md_acme_drive.c b/modules/md/md_acme_drive.c
new file mode 100644
index 0000000..4bb04f3
--- /dev/null
+++ b/modules/md/md_acme_drive.c
@@ -0,0 +1,1106 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_buckets.h>
+#include <apr_hash.h>
+#include <apr_uri.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_jws.h"
+#include "md_http.h"
+#include "md_log.h"
+#include "md_result.h"
+#include "md_reg.h"
+#include "md_store.h"
+#include "md_util.h"
+
+#include "md_acme.h"
+#include "md_acme_acct.h"
+#include "md_acme_authz.h"
+#include "md_acme_order.h"
+
+#include "md_acme_drive.h"
+#include "md_acmev2_drive.h"
+
+/**************************************************************************************************/
+/* account setup */
+
+static apr_status_t use_staged_acct(md_acme_t *acme, struct md_store_t *store,
+                                    const md_t *md, apr_pool_t *p)
+{
+    md_acme_acct_t *acct;
+    md_pkey_t *pkey;
+    apr_status_t rv;
+    
+    if (APR_SUCCESS == (rv = md_acme_acct_load(&acct, &pkey, store, 
+                                               MD_SG_STAGING, md->name, acme->p))) {
+        acme->acct_id = NULL;
+        acme->acct = acct;
+        acme->acct_key = pkey;
+        rv = md_acme_acct_validate(acme, NULL, p);
+    }
+    return rv;
+}
+
+static apr_status_t save_acct_staged(md_acme_t *acme, md_store_t *store, 
+                                     const char *md_name, apr_pool_t *p)
+{
+    md_json_t *jacct;
+    apr_status_t rv;
+    
+    jacct = md_acme_acct_to_json(acme->acct, p);
+    
+    rv = md_store_save(store, p, MD_SG_STAGING, md_name, MD_FN_ACCOUNT, MD_SV_JSON, jacct, 0);
+    if (APR_SUCCESS == rv) {
+        rv = md_store_save(store, p, MD_SG_STAGING, md_name, MD_FN_ACCT_KEY, 
+                           MD_SV_PKEY, acme->acct_key, 0);
+    }
+    return rv;
+}
+
+apr_status_t md_acme_drive_set_acct(md_proto_driver_t *d, md_result_t *result) 
+{
+    md_acme_driver_t *ad = d->baton;
+    md_t *md = ad->md;
+    apr_status_t rv = APR_SUCCESS;
+    int update_md = 0, update_acct = 0;
+    
+    md_result_activity_printf(result, "Selecting account to use for %s", d->md->name);
+    md_acme_clear_acct(ad->acme);
+    
+    /* Do we have a staged (modified) account? */
+    if (APR_SUCCESS == (rv = use_staged_acct(ad->acme, d->store, md, d->p))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "re-using staged account");
+    }
+    else if (!APR_STATUS_IS_ENOENT(rv)) {
+        goto leave;
+    }
+    
+    /* Get an account for the ACME server for this MD */
+    if (!ad->acme->acct && md->ca_account) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "re-use account '%s'", md->ca_account);
+        rv = md_acme_use_acct_for_md(ad->acme, d->store, d->p, md->ca_account, md);
+        if (APR_STATUS_IS_ENOENT(rv) || APR_STATUS_IS_EINVAL(rv)) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "rejected %s", md->ca_account);
+            md->ca_account = NULL;
+            update_md = 1;
+        }
+        else if (APR_SUCCESS != rv) {
+            goto leave;
+        }
+    }
+
+    if (!ad->acme->acct && !md->ca_account) {
+        /* Find a local account for server, store at MD */ 
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "%s: looking at existing accounts",
+                      d->proto->protocol);
+        if (APR_SUCCESS == (rv = md_acme_find_acct_for_md(ad->acme, d->store, md))) {
+            md->ca_account = md_acme_acct_id_get(ad->acme);
+            update_md = 1;
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "%s: using account %s (id=%s)",
+                          d->proto->protocol, ad->acme->acct->url, md->ca_account);
+        }
+    }
+    
+    if (!ad->acme->acct) {
+        /* No account staged, no suitable found in store, register a new one */
+        md_result_activity_printf(result, "Creating new ACME account for %s", d->md->name);
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "%s: creating new account", 
+                      d->proto->protocol);
+        
+        if (!ad->md->contacts || apr_is_empty_array(md->contacts)) {
+            rv = APR_EINVAL;
+            md_result_printf(result, rv, "No contact information is available for MD %s. "
+                             "Configure one using the MDContactEmail or ServerAdmin directive.", md->name);            
+            md_result_log(result, MD_LOG_ERR);
+            goto leave;
+        }
+        
+        /* ACMEv1 allowed registration of accounts without accepted Terms-of-Service.
+         * ACMEv2 requires it. Fail early in this case with a meaningful error message.
+         */ 
+        if (!md->ca_agreement) {
+            md_result_printf(result, APR_EINVAL,
+                  "the CA requires you to accept the terms-of-service "
+                  "as specified in <%s>. "
+                  "Please read the document that you find at that URL and, "
+                  "if you agree to the conditions, configure "
+                  "\"MDCertificateAgreement accepted\" "
+                  "in your Apache. Then (graceful) restart the server to activate.", 
+                  ad->acme->ca_agreement);
+            md_result_log(result, MD_LOG_ERR);
+            rv = result->status;
+            goto leave;
+        }
+    
+        if (ad->acme->eab_required && (!md->ca_eab_kid || !strcmp("none", md->ca_eab_kid))) {
+            md_result_printf(result, APR_EINVAL,
+                  "the CA requires 'External Account Binding' which is not "
+                  "configured. This means you need to obtain a 'Key ID' and a "
+                  "'HMAC' from the CA and configure that using the "
+                  "MDExternalAccountBinding directive in your config. "
+                  "The creation of a new ACME account will most likely fail, "
+                  "but an attempt is made anyway.",
+                  ad->acme->ca_agreement);
+            md_result_log(result, MD_LOG_INFO);
+        }
+
+        rv = md_acme_acct_register(ad->acme, d->store, md, d->p);
+        if (APR_SUCCESS != rv) {
+            if (APR_SUCCESS != ad->acme->last->status) {
+                md_result_dup(result, ad->acme->last);
+                md_result_log(result, MD_LOG_ERR);
+            }
+            goto leave;
+        }
+
+        md->ca_account = NULL;
+        update_md = 1;
+        update_acct = 1;
+    }
+    
+leave:
+    /* Persist MD changes in STAGING, so we pick them up on next run */
+    if (APR_SUCCESS == rv && update_md) {
+        rv = md_save(d->store, d->p, MD_SG_STAGING, ad->md, 0);
+    }
+    /* Persist account changes in STAGING, so we pick them up on next run */
+    if (APR_SUCCESS == rv && update_acct) {
+        rv = save_acct_staged(ad->acme, d->store, md->name, d->p);
+    }
+    return rv;
+}
+
+/**************************************************************************************************/
+/* poll cert */
+
+static void get_up_link(md_proto_driver_t *d, apr_table_t *headers)
+{
+    md_acme_driver_t *ad = d->baton;
+
+    ad->chain_up_link = md_link_find_relation(headers, d->p, "up");
+    if (ad->chain_up_link) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, 
+                      "server reports up link as %s", ad->chain_up_link);
+    }
+} 
+
+static apr_status_t add_http_certs(apr_array_header_t *chain, apr_pool_t *p,
+                                   const md_http_response_t *res)
+{
+    apr_status_t rv = APR_SUCCESS;
+    const char *ct;
+    
+    ct = apr_table_get(res->headers, "Content-Type");
+    ct = md_util_parse_ct(res->req->pool, ct);
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, p,
+                  "parse certs from %s -> %d (%s)", res->req->url, res->status, ct);
+    if (ct && !strcmp("application/x-pkcs7-mime", ct)) {
+        /* this looks like a root cert and we do not want those in our chain */
+        goto out; 
+    }
+
+    /* Lets try to read one or more certificates */
+    if (APR_SUCCESS != (rv = md_cert_chain_read_http(chain, p, res))
+        && APR_STATUS_IS_ENOENT(rv)) {
+        rv = APR_EAGAIN;
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, 
+                      "cert not in response from %s", res->req->url);
+    }
+out:
+    return rv;
+}
+
+static apr_status_t on_add_cert(md_acme_t *acme, const md_http_response_t *res, void *baton)
+{
+    md_proto_driver_t *d = baton;
+    md_acme_driver_t *ad = d->baton;
+    apr_status_t rv = APR_SUCCESS;
+    int count;
+    
+    (void)acme;
+    count = ad->cred->chain->nelts;
+    if (APR_SUCCESS == (rv = add_http_certs(ad->cred->chain, d->p, res))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "%d certs parsed", 
+                      ad->cred->chain->nelts - count);
+        get_up_link(d, res->headers);
+    }
+    return rv;
+}
+
+static apr_status_t get_cert(void *baton, int attempt)
+{
+    md_proto_driver_t *d = baton;
+    md_acme_driver_t *ad = d->baton;
+    
+    (void)attempt;
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, d->p, "retrieving cert from %s",
+                  ad->order->certificate);
+    return md_acme_GET(ad->acme, ad->order->certificate, NULL, NULL, on_add_cert, NULL, d);
+}
+
+apr_status_t md_acme_drive_cert_poll(md_proto_driver_t *d, int only_once)
+{
+    md_acme_driver_t *ad = d->baton;
+    apr_status_t rv;
+    
+    assert(ad->md);
+    assert(ad->acme);
+    assert(ad->order);
+    assert(ad->order->certificate);
+    
+    if (only_once) {
+        rv = get_cert(d, 0);
+    }
+    else {
+        rv = md_util_try(get_cert, d, 1, ad->cert_poll_timeout, 0, 0, 1);
+    }
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "poll for cert at %s", ad->order->certificate);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* order finalization */
+
+static apr_status_t on_init_csr_req(md_acme_req_t *req, void *baton)
+{
+    md_proto_driver_t *d = baton;
+    md_acme_driver_t *ad = d->baton;
+    md_json_t *jpayload;
+
+    jpayload = md_json_create(req->p);
+    md_json_sets(ad->csr_der_64, jpayload, MD_KEY_CSR, NULL);
+    
+    return md_acme_req_body_init(req, jpayload);
+} 
+
+static apr_status_t csr_req(md_acme_t *acme, const md_http_response_t *res, void *baton)
+{
+    md_proto_driver_t *d = baton;
+    md_acme_driver_t *ad = d->baton;
+    const char *location;
+    md_cert_t *cert;
+    apr_status_t rv = APR_SUCCESS;
+    
+    (void)acme;
+    location = apr_table_get(res->headers, "location");
+    if (!location) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, APR_EINVAL, d->p, 
+                      "cert created without giving its location header");
+        return APR_EINVAL;
+    }
+    ad->order->certificate = apr_pstrdup(d->p, location);
+    if (APR_SUCCESS != (rv = md_acme_order_save(d->store, d->p, MD_SG_STAGING, 
+                                                d->md->name, ad->order, 0))) { 
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, APR_EINVAL, d->p, 
+                      "%s: saving cert url %s", d->md->name, location);
+        return rv;
+    }
+    
+    /* Check if it already was sent with this response */
+    ad->chain_up_link = NULL;
+    if (APR_SUCCESS == (rv = md_cert_read_http(&cert, d->p, res))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "cert parsed");
+        apr_array_clear(ad->cred->chain);
+        APR_ARRAY_PUSH(ad->cred->chain, md_cert_t*) = cert;
+        get_up_link(d, res->headers);
+    }
+    else if (APR_STATUS_IS_ENOENT(rv)) {
+        rv = APR_SUCCESS;
+        if (location) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, 
+                          "cert not in response, need to poll %s", location);
+        }
+    }
+    
+    return rv;
+}
+
+/**
+ * Pre-Req: all domains have been validated by the ACME server, e.g. all have AUTHZ
+ * resources that have status 'valid'
+ *  - acme_driver->cred keeps the credentials to setup (key spec) 
+ * - Setup private key, if not already there
+ * - Generate a CSR with org, contact, etc
+ * - Optionally enable must-staple OCSP extension
+ * - Submit CSR, expect 201 with location
+ * - POLL location for certificate
+ * - store certificate
+ * - retrieve cert chain information from cert
+ * - GET cert chain
+ * - store cert chain
+ */
+apr_status_t md_acme_drive_setup_cred_chain(md_proto_driver_t *d, md_result_t *result)
+{
+    md_acme_driver_t *ad = d->baton;
+    md_pkey_spec_t *spec;
+    md_pkey_t *privkey;
+    apr_status_t rv;
+
+    md_result_activity_printf(result, "Finalizing order for %s", ad->md->name);
+
+    assert(ad->cred);
+    spec = ad->cred->spec;
+        
+    rv = md_pkey_load(d->store, MD_SG_STAGING, d->md->name, spec, &privkey, d->p);
+    if (APR_STATUS_IS_ENOENT(rv)) {
+        if (APR_SUCCESS == (rv = md_pkey_gen(&privkey, d->p, spec))) {
+            rv = md_pkey_save(d->store, d->p, MD_SG_STAGING, d->md->name, spec, privkey, 1);
+        }
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, 
+                      "%s: generate %s privkey", d->md->name, md_pkey_spec_name(spec));
+    }
+    if (APR_SUCCESS != rv) goto leave;
+    
+    md_result_activity_printf(result, "Creating %s CSR", md_pkey_spec_name(spec));
+    rv = md_cert_req_create(&ad->csr_der_64, d->md->name, ad->domains, 
+                            ad->md->must_staple, privkey, d->p);
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "%s: create %s CSR", 
+                  d->md->name, md_pkey_spec_name(spec));
+    if (APR_SUCCESS != rv) goto leave;
+    
+    md_result_activity_printf(result, "Submitting %s CSR to CA", md_pkey_spec_name(spec));
+    assert(ad->order->finalize);
+    rv = md_acme_POST(ad->acme, ad->order->finalize, on_init_csr_req, NULL, csr_req, NULL, d);
+
+leave:
+    md_acme_report_result(ad->acme, rv, result);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* cert chain retrieval */
+
+static apr_status_t on_add_chain(md_acme_t *acme, const md_http_response_t *res, void *baton)
+{
+    md_proto_driver_t *d = baton;
+    md_acme_driver_t *ad = d->baton;
+    apr_status_t rv = APR_SUCCESS;
+    const char *ct;
+    
+    (void)acme;
+    ct = apr_table_get(res->headers, "Content-Type");
+    ct = md_util_parse_ct(res->req->pool, ct);
+    if (ct && !strcmp("application/x-pkcs7-mime", ct)) {
+        /* root cert most likely, end it here */
+        return APR_SUCCESS;
+    }
+    
+    if (APR_SUCCESS == (rv = add_http_certs(ad->cred->chain, d->p, res))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "chain cert parsed");
+        get_up_link(d, res->headers);
+    }
+    return rv;
+}
+
+static apr_status_t get_chain(void *baton, int attempt)
+{
+    md_proto_driver_t *d = baton;
+    md_acme_driver_t *ad = d->baton;
+    const char *prev_link = NULL;
+    apr_status_t rv = APR_SUCCESS;
+
+    while (APR_SUCCESS == rv && ad->cred->chain->nelts < 10) {
+        int nelts = ad->cred->chain->nelts;
+        
+        if (ad->chain_up_link && (!prev_link || strcmp(prev_link, ad->chain_up_link))) {
+            prev_link = ad->chain_up_link;
+
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, 
+                          "next chain cert at  %s", ad->chain_up_link);
+            rv = md_acme_GET(ad->acme, ad->chain_up_link, NULL, NULL, on_add_chain, NULL, d);
+            
+            if (APR_SUCCESS == rv && nelts == ad->cred->chain->nelts) {
+                break;
+            }
+            else if (APR_SUCCESS != rv) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, d->p,
+                              "error retrieving certificate from %s", ad->chain_up_link);
+                return rv;
+            }
+        }
+        else if (ad->cred->chain->nelts <= 1) {
+            /* This cannot be the complete chain (no one signs new web certs with their root)
+             * and we did not see a "Link: ...rel=up", so we do not know how to continue. */
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, d->p, 
+                          "no link header 'up' for new certificate, unable to retrieve chain");
+            rv = APR_EINVAL;
+            break;
+        }
+        else {
+            rv = APR_SUCCESS;
+            break;
+        }
+    }
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, d->p, 
+                  "got chain with %d certs (%d. attempt)", ad->cred->chain->nelts, attempt);
+    return rv;
+}
+
+static apr_status_t ad_chain_retrieve(md_proto_driver_t *d)
+{
+    md_acme_driver_t *ad = d->baton;
+    apr_status_t rv;
+    
+    /* This may be called repeatedly and needs to progress. The relevant state is in
+     * ad->cred->chain          the certificate chain, starting with the new cert for the md
+     * ad->order->certificate   the url where ACME offers us the new md certificate. This may
+     *                          be a single one or even the complete chain
+     * ad->chain_up_link         in case the last certificate retrieval did not end the chain,
+     *                          the link header with relation "up" gives us the location
+     *                          for the next cert in the chain
+     */
+    if (md_array_is_empty(ad->cred->chain)) {
+        /* Need to start at the order */
+        ad->chain_up_link = NULL;
+        if (!ad->order) {
+            rv = APR_EGENERAL;
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, d->p, 
+                "%s: asked to retrieve chain, but no order in context", d->md->name);
+            goto out;
+        }
+        if (!ad->order->certificate) {
+            rv = APR_EGENERAL;
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, d->p, 
+                "%s: asked to retrieve chain, but no certificate url part of order", d->md->name);
+            goto out;
+        }
+        
+        if (APR_SUCCESS != (rv = md_acme_drive_cert_poll(d, 0))) {
+            goto out;
+        }
+    }
+    
+    rv = md_util_try(get_chain, d, 0, ad->cert_poll_timeout, 0, 0, 0);
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "chain retrieved");
+    
+out:
+    return rv;
+}
+
+/**************************************************************************************************/
+/* ACME driver init */
+
+static apr_status_t acme_driver_preload_init(md_proto_driver_t *d, md_result_t *result)
+{
+    md_acme_driver_t *ad;
+    md_credentials_t *cred;
+    int i;
+    
+    md_result_set(result, APR_SUCCESS, NULL);
+    
+    ad = apr_pcalloc(d->p, sizeof(*ad));
+    
+    d->baton = ad;
+    
+    ad->driver = d;
+    ad->authz_monitor_timeout = apr_time_from_sec(30);
+    ad->cert_poll_timeout = apr_time_from_sec(30);
+    ad->ca_challenges = apr_array_make(d->p, 3, sizeof(const char*));
+    
+    /* We want to obtain credentials (key+certificate) for every key spec in this MD */
+    ad->creds = apr_array_make(d->p, md_pkeys_spec_count(d->md->pks), sizeof(md_credentials_t*));
+    for (i = 0; i < md_pkeys_spec_count(d->md->pks); ++i) {
+        cred = apr_pcalloc(d->p, sizeof(*cred));
+        cred->spec = md_pkeys_spec_get(d->md->pks, i);
+        cred->chain = apr_array_make(d->p, 5, sizeof(md_cert_t*));
+        APR_ARRAY_PUSH(ad->creds, md_credentials_t*) = cred;
+    }
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, result->status, d->p, 
+                  "%s: init_base driver", d->md->name);
+    return result->status;
+}
+
+static apr_status_t acme_driver_init(md_proto_driver_t *d, md_result_t *result)
+{
+    md_acme_driver_t *ad;
+    int dis_http, dis_https, dis_alpn_acme, dis_dns;
+    const char *challenge;
+
+    acme_driver_preload_init(d, result);
+    md_result_set(result, APR_SUCCESS, NULL);
+    if (APR_SUCCESS != result->status) goto leave;
+    
+    ad = d->baton;
+
+    /* We can only support challenges if the server is reachable from the outside
+     * via port 80 and/or 443. These ports might be mapped for httpd to something
+     * else, but a mapping needs to exist. */
+    challenge = apr_table_get(d->env, MD_KEY_CHALLENGE); 
+    if (challenge) {
+        APR_ARRAY_PUSH(ad->ca_challenges, const char*) = apr_pstrdup(d->p, challenge);
+    }
+    else if (d->md->ca_challenges && d->md->ca_challenges->nelts > 0) {
+        /* pre-configured set for this managed domain */
+        apr_array_cat(ad->ca_challenges, d->md->ca_challenges);
+    }
+    else {
+        /* free to chose. Add all we support and see what we get offered */
+        APR_ARRAY_PUSH(ad->ca_challenges, const char*) = MD_AUTHZ_TYPE_TLSALPN01;
+        APR_ARRAY_PUSH(ad->ca_challenges, const char*) = MD_AUTHZ_TYPE_HTTP01;
+        APR_ARRAY_PUSH(ad->ca_challenges, const char*) = MD_AUTHZ_TYPE_DNS01;
+
+        if (!d->can_http && !d->can_https 
+            && md_array_str_index(ad->ca_challenges, MD_AUTHZ_TYPE_DNS01, 0, 0) < 0) {
+            md_result_printf(result, APR_EGENERAL,
+                             "the server seems neither reachable via http (port 80) nor https (port 443). "
+                             "Please look at the MDPortMap configuration directive on how to correct this. "
+                             "The ACME protocol needs at least one of those so the CA can talk to the server "
+                             "and verify a domain ownership. Alternatively, you may configure support "
+                             "for the %s challenge directive.", MD_AUTHZ_TYPE_DNS01);
+            goto leave;
+        }
+
+        dis_http = dis_https = dis_alpn_acme = dis_dns = 0;
+        if (!d->can_http && md_array_str_index(ad->ca_challenges, MD_AUTHZ_TYPE_HTTP01, 0, 1) >= 0) {
+            ad->ca_challenges = md_array_str_remove(d->p, ad->ca_challenges, MD_AUTHZ_TYPE_HTTP01, 0);
+            dis_http = 1;
+        }
+        if (!d->can_https && md_array_str_index(ad->ca_challenges, MD_AUTHZ_TYPE_TLSALPN01, 0, 1) >= 0) {
+            ad->ca_challenges = md_array_str_remove(d->p, ad->ca_challenges, MD_AUTHZ_TYPE_TLSALPN01, 0);
+            dis_https = 1;
+        }
+        if (apr_is_empty_array(d->md->acme_tls_1_domains)
+            && md_array_str_index(ad->ca_challenges, MD_AUTHZ_TYPE_TLSALPN01, 0, 1) >= 0) {
+            ad->ca_challenges = md_array_str_remove(d->p, ad->ca_challenges, MD_AUTHZ_TYPE_TLSALPN01, 0);
+            dis_alpn_acme = 1;
+        }
+        if (!apr_table_get(d->env, MD_KEY_CMD_DNS01)
+            && NULL == d->md->dns01_cmd
+            && md_array_str_index(ad->ca_challenges, MD_AUTHZ_TYPE_DNS01, 0, 1) >= 0) {
+            ad->ca_challenges = md_array_str_remove(d->p, ad->ca_challenges, MD_AUTHZ_TYPE_DNS01, 0);
+            dis_dns = 1;
+        }
+
+        if (apr_is_empty_array(ad->ca_challenges)) {
+            md_result_printf(result, APR_EGENERAL, 
+                             "None of the ACME challenge methods configured for this domain are suitable.%s%s%s%s",
+                             dis_http? " The http: challenge 'http-01' is disabled because the server seems not reachable on public port 80." : "",
+                             dis_https? " The https: challenge 'tls-alpn-01' is disabled because the server seems not reachable on public port 443." : "",
+                             dis_alpn_acme? " The https: challenge 'tls-alpn-01' is disabled because the Protocols configuration does not include the 'acme-tls/1' protocol." : "",
+                             dis_dns? " The DNS challenge 'dns-01' is disabled because the directive 'MDChallengeDns01' is not configured." : ""
+                             );
+            goto leave;
+        }
+    }
+
+    md_result_printf(result, 0, "MDomain %s initialized with support for ACME challenges %s",
+              d->md->name, apr_array_pstrcat(d->p, ad->ca_challenges, ' '));
+
+leave:    
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, result->status, d->p, "%s: init driver", d->md->name);
+    return result->status;
+}
+
+/**************************************************************************************************/
+/* ACME staging */
+
+static apr_status_t load_missing_creds(md_proto_driver_t *d)
+{
+    md_acme_driver_t *ad = d->baton;
+    md_credentials_t *cred;
+    apr_array_header_t *chain;
+    int i, complete;
+    apr_status_t rv;
+    
+    complete = 1;
+    for (i = 0; i < ad->creds->nelts; ++i) {
+        rv = APR_SUCCESS;
+        cred = APR_ARRAY_IDX(ad->creds, i, md_credentials_t*);
+        if (!cred->pkey) {
+            rv = md_pkey_load(d->store, MD_SG_STAGING, d->md->name, cred->spec, &cred->pkey, d->p);
+        }
+        if (APR_SUCCESS == rv && md_array_is_empty(cred->chain)) {
+            rv = md_pubcert_load(d->store, MD_SG_STAGING, d->md->name, cred->spec, &chain, d->p);
+            if (APR_SUCCESS == rv) {
+                apr_array_cat(cred->chain, chain);
+            }
+        }
+        if (APR_SUCCESS == rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, d->p, "%s: credentials staged for %s certificate", 
+                          d->md->name, md_pkey_spec_name(cred->spec));
+        }
+        else {
+            complete = 0;
+        }
+    }
+    return complete? APR_SUCCESS : APR_EAGAIN;
+}
+
+static apr_status_t acme_renew(md_proto_driver_t *d, md_result_t *result)
+{
+    md_acme_driver_t *ad = d->baton;
+    int reset_staging = d->reset;
+    apr_status_t rv = APR_SUCCESS;
+    apr_time_t now, t, t2;
+    md_credentials_t *cred;
+    const char *ca_effective = NULL;
+    char ts[APR_RFC822_DATE_LEN];
+    int i, first = 0;
+
+    if (!d->md->ca_urls || d->md->ca_urls->nelts <= 0) {
+        /* No CA defined? This is checked in several other places, but lets be sure */
+        md_result_printf(result, APR_INCOMPLETE,
+            "The managed domain %s is missing MDCertificateAuthority", d->md->name);
+        goto out;
+    }
+
+    /* When not explicitly told to reset, we check the existing data. If
+     * it is incomplete or old, we trigger the reset for a clean start. */
+    if (!reset_staging) {
+        md_result_activity_setn(result, "Checking staging area");
+        rv = md_load(d->store, MD_SG_STAGING, d->md->name, &ad->md, d->p);
+        if (APR_SUCCESS == rv) {
+            /* So, we have a copy in staging, but is it a recent or an old one? */
+            if (md_is_newer(d->store, MD_SG_DOMAINS, MD_SG_STAGING, d->md->name, d->p)) {
+                reset_staging = 1;
+            }
+        }
+        else if (APR_STATUS_IS_ENOENT(rv)) {
+            reset_staging = 1;
+            rv = APR_SUCCESS;
+        }
+    }
+
+    /* What CA are we using this time? */
+    if (ad->md && ad->md->ca_effective) {
+        /* There was one chosen on the previous run. Do we stick to it? */
+        ca_effective = ad->md->ca_effective;
+        if (d->md->ca_urls->nelts > 1 && d->attempt >= d->retry_failover) {
+            /* We have more than one CA to choose from and this is the (at least)
+             * third attempt with the same CA. Let's switch to the next one. */
+            int last_idx = md_array_str_index(d->md->ca_urls, ca_effective, 0, 1);
+            if (last_idx >= 0) {
+                int next_idx = (last_idx+1) % d->md->ca_urls->nelts;
+                ca_effective = APR_ARRAY_IDX(d->md->ca_urls, next_idx, const char*);
+            }
+            else {
+                /* not part of current configuration? */
+                ca_effective = NULL;
+            }
+            /* switching CA means we need to wipe the staging area */
+            reset_staging = 1;
+        }
+    }
+
+    if (!ca_effective) {
+        /* None chosen yet, pick the first one configured */
+        ca_effective = APR_ARRAY_IDX(d->md->ca_urls, 0, const char*);
+    }
+
+    if (md_log_is_level(d->p, MD_LOG_DEBUG)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: staging started, "
+                      "state=%d, attempt=%d, acme=%s, challenges='%s'",
+                      d->md->name, d->md->state, d->attempt, ca_effective,
+                      apr_array_pstrcat(d->p, ad->ca_challenges, ' '));
+    }
+
+    if (reset_staging) {
+        md_result_activity_setn(result, "Resetting staging area");
+        /* reset the staging area for this domain */
+        rv = md_store_purge(d->store, d->p, MD_SG_STAGING, d->md->name);
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, d->p, 
+                      "%s: reset staging area", d->md->name);
+        if (APR_SUCCESS != rv && !APR_STATUS_IS_ENOENT(rv)) {
+            md_result_printf(result, rv, "resetting staging area");
+            goto out;
+        }
+        rv = APR_SUCCESS;
+        ad->md = NULL;
+        ad->order = NULL;
+    }
+    
+    md_result_activity_setn(result, "Assessing current status");
+    if (ad->md && ad->md->state == MD_S_MISSING_INFORMATION) {
+        /* ToS agreement is missing. It makes no sense to drive this MD further */
+        md_result_printf(result, APR_INCOMPLETE, 
+            "The managed domain %s is missing required information", d->md->name);
+        goto out;
+    }
+    
+    if (ad->md && APR_SUCCESS == load_missing_creds(d)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: all credentials staged", d->md->name);
+        goto ready;
+    }
+    
+    /* Need to renew */
+    if (!ad->md || !md_array_str_eq(ad->md->ca_urls, d->md->ca_urls, 1)) {
+        md_result_activity_printf(result, "Resetting staging for %s", d->md->name);
+        /* re-initialize staging */
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: setup staging", d->md->name);
+        md_store_purge(d->store, d->p, MD_SG_STAGING, d->md->name);
+        ad->md = md_copy(d->p, d->md);
+        ad->md->ca_effective = ca_effective;
+        ad->md->ca_account = NULL;
+        ad->order = NULL;
+        rv = md_save(d->store, d->p, MD_SG_STAGING, ad->md, 0);
+        if (APR_SUCCESS != rv) {
+            md_result_printf(result, rv, "Saving MD information in staging area.");
+            md_result_log(result, MD_LOG_ERR);
+            goto out;
+        }
+    }
+    if (!ad->domains) {
+        ad->domains = md_dns_make_minimal(d->p, ad->md->domains);
+    }
+    
+    md_result_activity_printf(result, "Contacting ACME server for %s at %s",
+                              d->md->name, ca_effective);
+    if (APR_SUCCESS != (rv = md_acme_create(&ad->acme, d->p, ca_effective,
+                                            d->proxy_url, d->ca_file))) {
+        md_result_printf(result, rv, "setup ACME communications");
+        md_result_log(result, MD_LOG_ERR);
+        goto out;
+    }
+    if (APR_SUCCESS != (rv = md_acme_setup(ad->acme, result))) {
+        md_result_log(result, MD_LOG_ERR);
+        goto out;
+    }
+
+    if (APR_SUCCESS != load_missing_creds(d)) {
+        for (i = 0; i < ad->creds->nelts; ++i) {
+            ad->cred = APR_ARRAY_IDX(ad->creds, i, md_credentials_t*);
+            if (!ad->cred->pkey || md_array_is_empty(ad->cred->chain)) {
+                md_result_activity_printf(result, "Driving ACME to renew %s certificate for %s", 
+                                          md_pkey_spec_name(ad->cred->spec),d->md->name);
+                /* The process of setting up challenges and verifying domain
+                 * names differs between ACME versions. */
+                switch (MD_ACME_VERSION_MAJOR(ad->acme->version)) {
+                    case 1:
+                        md_result_printf(result, APR_EINVAL,
+                            "ACME server speaks version 1, an obsolete version of the ACME "
+                            "protocol that is no longer supported.");
+                        rv = result->status;
+                        break;
+                    default:
+                        /* In principle, we only know ACME version 2. But we assume
+                        that a new protocol which announces a directory with all members
+                        from version 2 will act backward compatible.
+                        This is, of course, an assumption...
+                        */
+                        rv = md_acmev2_drive_renew(ad, d, result);
+                        break;
+                }
+                if (APR_SUCCESS != rv) goto out;
+                
+                if (md_array_is_empty(ad->cred->chain) || ad->chain_up_link) {
+                    md_result_activity_printf(result, "Retrieving %s certificate chain for %s", 
+                                              md_pkey_spec_name(ad->cred->spec), d->md->name);
+                    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, 
+                                  "%s: retrieving %s certificate chain", 
+                                  d->md->name, md_pkey_spec_name(ad->cred->spec));
+                    rv = ad_chain_retrieve(d);
+                    if (APR_SUCCESS != rv) {
+                        md_result_printf(result, rv, "Unable to retrieve %s certificate chain.", 
+                                         md_pkey_spec_name(ad->cred->spec));
+                        goto out;
+                    }
+                    
+                    if (!md_array_is_empty(ad->cred->chain)) {
+
+                        if (!ad->cred->pkey) {
+                            rv = md_pkey_load(d->store, MD_SG_STAGING, d->md->name, ad->cred->spec, &ad->cred->pkey, d->p);
+                            if (APR_SUCCESS != rv) {
+                                md_result_printf(result, rv, "Loading the private key.");
+                                goto out;
+                            }
+                        }
+
+                        if (ad->cred->pkey) {
+                            rv = md_check_cert_and_pkey(ad->cred->chain, ad->cred->pkey);
+                            if (APR_SUCCESS != rv) {
+                                md_result_printf(result, rv, "Certificate and private key do not match.");
+
+                                /* Delete the order */
+                                md_acme_order_purge(d->store, d->p, MD_SG_STAGING, d->md, d->env);
+
+                                goto out;
+                            }
+                        }
+
+                        rv = md_pubcert_save(d->store, d->p, MD_SG_STAGING, d->md->name, 
+                                             ad->cred->spec, ad->cred->chain, 0);
+                        if (APR_SUCCESS != rv) {
+                            md_result_printf(result, rv, "Saving new %s certificate chain.", 
+                                             md_pkey_spec_name(ad->cred->spec));
+                            goto out;
+                        }
+                    }
+                }
+                
+                /* Clean up the order, so the next pkey spec sets up a new one */
+                md_acme_order_purge(d->store, d->p, MD_SG_STAGING, d->md, d->env);
+            }
+        }
+    }
+    
+    
+    /* As last step, cleanup any order we created so that challenge data
+     * may be removed asap. */
+    md_acme_order_purge(d->store, d->p, MD_SG_STAGING, d->md, d->env);
+    
+    /* first time this job ran through */
+    first = 1;    
+ready:
+    md_result_activity_setn(result, NULL);
+    /* we should have the complete cert chain now */
+    assert(APR_SUCCESS == load_missing_creds(d));
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, d->p, 
+                  "%s: certificates ready, activation delay set to %s", 
+                  d->md->name, md_duration_format(d->p, d->activation_delay));
+    
+    /* determine when it should be activated */
+    t = apr_time_now();
+    for (i = 0; i < ad->creds->nelts; ++i) {
+        cred = APR_ARRAY_IDX(ad->creds, i, md_credentials_t*);
+        t2 = md_cert_get_not_before(APR_ARRAY_IDX(cred->chain, 0, md_cert_t*));
+        if (t2 > t) t = t2;
+    }
+    md_result_delay_set(result, t);
+
+    /* If the existing MD is complete and un-expired, delay the activation
+     * to 24 hours after new cert is valid (if there is enough time left), so
+     * that cients with skewed clocks do not see a problem. */
+    now = apr_time_now();
+    if (d->md->state == MD_S_COMPLETE) {
+        apr_time_t valid_until, delay_activation;
+        
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, d->p, 
+                      "%s: state is COMPLETE, checking existing certificates", d->md->name);
+        valid_until = md_reg_valid_until(d->reg, d->md, d->p);
+        if (d->activation_delay < 0) {
+            /* special simulation for test case */
+            if (first) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, 
+                              "%s: delay ready_at to now+1s", d->md->name);
+                md_result_delay_set(result, apr_time_now() + apr_time_from_sec(1));
+            }
+        }
+        else if (valid_until > now) {            
+            delay_activation = d->activation_delay;
+            if (delay_activation > (valid_until - now)) {
+                delay_activation = (valid_until - now);
+            }
+            md_result_delay_set(result, result->ready_at + delay_activation);
+        }
+    }
+    
+    /* There is a full set staged, to be loaded */
+    apr_rfc822_date(ts, result->ready_at);
+    if (result->ready_at > now) {
+        md_result_printf(result, APR_SUCCESS, 
+            "The certificate for the managed domain has been renewed successfully and can "
+            "be used from %s on.", ts);
+    }
+    else {
+        md_result_printf(result, APR_SUCCESS, 
+            "The certificate for the managed domain has been renewed successfully and can "
+            "be used (valid since %s). A graceful server restart now is recommended.", ts);
+    }
+
+out:
+    return rv;
+}
+
+static apr_status_t acme_driver_renew(md_proto_driver_t *d, md_result_t *result)
+{
+    apr_status_t rv;
+
+    rv = acme_renew(d, result);
+    md_result_log(result, MD_LOG_DEBUG);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* ACME preload */
+
+static apr_status_t acme_preload(md_proto_driver_t *d, md_store_group_t load_group, 
+                                 const char *name, md_result_t *result) 
+{
+    apr_status_t rv;
+    md_pkey_t *acct_key;
+    md_t *md;
+    md_pkey_spec_t *pkspec;
+    md_credentials_t *creds;
+    apr_array_header_t *all_creds;
+    struct md_acme_acct_t *acct;
+    const char *id;
+    int i;
+
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: preload start", name);
+    /* Load data from MD_SG_STAGING and save it into "load_group".
+     * This serves several purposes:
+     *  1. It's a format check on the input data. 
+     *  2. We write back what we read, creating data with our own access permissions
+     *  3. We ignore any other accumulated data in STAGING
+     *  4. Once "load_group" is complete an ok, we can swap/archive groups with a rename
+     *  5. Reading/Writing the data will apply/remove any group specific data encryption.
+     */
+    if (APR_SUCCESS != (rv = md_load(d->store, MD_SG_STAGING, name, &md, d->p))) {
+        md_result_set(result, rv, "loading staged md.json");
+        goto leave;
+    }
+    if (!md->ca_effective) {
+        rv = APR_ENOENT;
+        md_result_set(result, rv, "effective CA url not set");
+        goto leave;
+    }
+
+    all_creds = apr_array_make(d->p, 5, sizeof(md_credentials_t*));
+    for (i = 0; i < md_pkeys_spec_count(md->pks); ++i) {
+        pkspec = md_pkeys_spec_get(md->pks, i);
+        if (APR_SUCCESS != (rv = md_creds_load(d->store, MD_SG_STAGING, name, pkspec, &creds, d->p))) {
+            md_result_printf(result, rv, "loading staged credentials #%d", i);
+            goto leave;
+        }
+        if (!creds->chain) {
+            rv = APR_ENOENT;
+            md_result_printf(result, rv, "no certificate in staged credentials #%d", i);
+            goto leave;
+        }
+        if (APR_SUCCESS != (rv = md_check_cert_and_pkey(creds->chain, creds->pkey))) {
+            md_result_printf(result, rv, "certificate and private key do not match in staged credentials #%d", i);
+            goto leave;
+        }
+        APR_ARRAY_PUSH(all_creds, md_credentials_t*) = creds;
+    }
+    
+    /* See if staging holds a new or modified account data */
+    rv = md_acme_acct_load(&acct, &acct_key, d->store, MD_SG_STAGING, name, d->p);
+    if (APR_STATUS_IS_ENOENT(rv)) {
+        acct = NULL;
+        acct_key = NULL;
+        rv = APR_SUCCESS;
+    }
+    else if (APR_SUCCESS != rv) {
+        md_result_set(result, rv, "loading staged account");
+        goto leave;
+    }
+
+    md_result_activity_setn(result, "purging order information");
+    md_acme_order_purge(d->store, d->p, MD_SG_STAGING, md, d->env);
+
+    md_result_activity_setn(result, "purging store tmp space");
+    rv = md_store_purge(d->store, d->p, load_group, name);
+    if (APR_SUCCESS != rv) {
+        md_result_set(result, rv, NULL);
+        goto leave;
+    }
+    
+    if (acct) {
+        md_acme_t *acme;
+
+        /* We may have STAGED the same account several times. This happens when
+         * several MDs are renewed at once and need a new account. They will all store
+         * the new account in their own STAGING area. By checking for accounts with
+         * the same url, we save them all into a single one.
+         */
+        md_result_activity_setn(result, "saving staged account");
+        id = md->ca_account;
+        if (!id) {
+            rv = md_acme_acct_id_for_md(&id, d->store, MD_SG_ACCOUNTS, md, d->p);
+            if (APR_STATUS_IS_ENOENT(rv)) {
+                id = NULL;
+            }
+            else if (APR_SUCCESS != rv) {
+                md_result_set(result, rv, "error searching for existing account by url");
+                goto leave;
+            }
+        }
+        
+        if (APR_SUCCESS != (rv = md_acme_create(&acme, d->p, md->ca_effective,
+                                                d->proxy_url, d->ca_file))) {
+            md_result_set(result, rv, "error setting up acme");
+            goto leave;
+        }
+        
+        if (APR_SUCCESS != (rv = md_acme_acct_save(d->store, d->p, acme, &id, acct, acct_key))) {
+            md_result_set(result, rv, "error saving account");
+            goto leave;
+        }
+        md->ca_account = id;
+    }
+    else if (!md->ca_account) {
+        /* staging reused another account and did not create a new one. find
+         * the account, if it is already there */
+        rv = md_acme_acct_id_for_md(&id, d->store, MD_SG_ACCOUNTS, md, d->p);
+        if (APR_SUCCESS == rv) {
+            md->ca_account = id;
+        }
+    }
+    
+    md_result_activity_setn(result, "saving staged md/privkey/pubcert");
+    if (APR_SUCCESS != (rv = md_save(d->store, d->p, load_group, md, 1))) {
+        md_result_set(result, rv, "writing md.json");
+        goto leave;
+    }
+
+    for (i = 0; i < all_creds->nelts; ++i) {
+        creds = APR_ARRAY_IDX(all_creds, i, md_credentials_t*);
+        if (APR_SUCCESS != (rv = md_creds_save(d->store, d->p, load_group, name, creds, 1))) {
+            md_result_printf(result, rv, "writing credentials #%d", i);
+            goto leave;
+        }
+    }
+    
+    md_result_set(result, APR_SUCCESS, "saved staged data successfully");
+    
+leave:
+    md_result_log(result, MD_LOG_DEBUG);
+    return rv;
+}
+
+static apr_status_t acme_driver_preload(md_proto_driver_t *d, 
+                                        md_store_group_t group, md_result_t *result)
+{
+    apr_status_t rv;
+
+    rv = acme_preload(d, group, d->md->name, result);
+    md_result_log(result, MD_LOG_DEBUG);
+    return rv;
+}
+
+static apr_status_t acme_complete_md(md_t *md, apr_pool_t *p)
+{
+    (void)p;
+    if (!md->ca_urls || apr_is_empty_array(md->ca_urls)) {
+        md->ca_urls = apr_array_make(p, 3, sizeof(const char *));
+        APR_ARRAY_PUSH(md->ca_urls, const char*) = MD_ACME_DEF_URL;
+    }
+    return APR_SUCCESS;
+}
+
+static md_proto_t ACME_PROTO = {
+    MD_PROTO_ACME, acme_driver_init, acme_driver_renew, 
+    acme_driver_preload_init, acme_driver_preload,
+    acme_complete_md,
+};
+ 
+apr_status_t md_acme_protos_add(apr_hash_t *protos, apr_pool_t *p)
+{
+    (void)p;
+    apr_hash_set(protos, MD_PROTO_ACME, sizeof(MD_PROTO_ACME)-1, &ACME_PROTO);
+    return APR_SUCCESS;
+}
diff --git a/modules/md/md_acme_drive.h b/modules/md/md_acme_drive.h
new file mode 100644
index 0000000..88761fa
--- /dev/null
+++ b/modules/md/md_acme_drive.h
@@ -0,0 +1,55 @@
+/* Copyright 2019 greenbytes GmbH (https://www.greenbytes.de)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef md_acme_drive_h
+#define md_acme_drive_h
+
+struct apr_array_header_t;
+struct md_acme_order_t;
+struct md_credentials_t;
+struct md_result_t;
+
+typedef struct md_acme_driver_t {
+    md_proto_driver_t *driver;
+    void *sub_driver;
+    
+    md_acme_t *acme;
+    md_t *md;
+    struct apr_array_header_t *domains;
+    apr_array_header_t *ca_challenges;
+    
+    int complete;
+    apr_array_header_t *creds;       /* the new md_credentials_t */
+
+    struct md_credentials_t *cred;   /* credentials currently being processed */ 
+    const char *chain_up_link;       /* Link header "up" from last chain retrieval,
+                                        needs to be followed */
+
+    struct md_acme_order_t *order;
+    apr_interval_time_t authz_monitor_timeout;
+    
+    const char *csr_der_64;
+    apr_interval_time_t cert_poll_timeout;
+    
+} md_acme_driver_t;
+
+apr_status_t md_acme_drive_set_acct(struct md_proto_driver_t *d, 
+                                    struct md_result_t *result);
+apr_status_t md_acme_drive_setup_cred_chain(struct md_proto_driver_t *d, 
+                                            struct md_result_t *result);
+apr_status_t md_acme_drive_cert_poll(struct md_proto_driver_t *d, int only_once);
+
+#endif /* md_acme_drive_h */
+
diff --git a/modules/md/md_acme_order.c b/modules/md/md_acme_order.c
new file mode 100644
index 0000000..9e25e84
--- /dev/null
+++ b/modules/md/md_acme_order.c
@@ -0,0 +1,562 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stdio.h>
+
+#include <apr_lib.h>
+#include <apr_buckets.h>
+#include <apr_file_info.h>
+#include <apr_file_io.h>
+#include <apr_fnmatch.h>
+#include <apr_hash.h>
+#include <apr_strings.h>
+#include <apr_tables.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_http.h"
+#include "md_log.h"
+#include "md_jws.h"
+#include "md_result.h"
+#include "md_store.h"
+#include "md_util.h"
+
+#include "md_acme.h"
+#include "md_acme_authz.h"
+#include "md_acme_order.h"
+
+
+md_acme_order_t *md_acme_order_create(apr_pool_t *p)
+{
+    md_acme_order_t *order;
+    
+    order = apr_pcalloc(p, sizeof(*order));
+    order->p = p;
+    order->authz_urls = apr_array_make(p, 5, sizeof(const char *));
+    order->challenge_setups = apr_array_make(p, 5, sizeof(const char *));
+    
+    return order;
+}
+
+/**************************************************************************************************/
+/* order conversion */
+
+#define MD_KEY_CHALLENGE_SETUPS   "challenge-setups"
+
+static md_acme_order_st order_st_from_str(const char *s) 
+{
+    if (s) {
+        if (!strcmp("valid", s)) {
+            return MD_ACME_ORDER_ST_VALID;
+        }
+        else if (!strcmp("invalid", s)) {
+            return MD_ACME_ORDER_ST_INVALID;
+        }
+        else if (!strcmp("ready", s)) {
+            return MD_ACME_ORDER_ST_READY;
+        }
+        else if (!strcmp("pending", s)) {
+            return MD_ACME_ORDER_ST_PENDING;
+        }
+        else if (!strcmp("processing", s)) {
+            return MD_ACME_ORDER_ST_PROCESSING;
+        }
+    }
+    return MD_ACME_ORDER_ST_PENDING;
+}
+
+static const char *order_st_to_str(md_acme_order_st status) 
+{
+    switch (status) {
+        case MD_ACME_ORDER_ST_PENDING:
+            return "pending";
+        case MD_ACME_ORDER_ST_READY:
+            return "ready";
+        case MD_ACME_ORDER_ST_PROCESSING:
+            return "processing";
+        case MD_ACME_ORDER_ST_VALID:
+            return "valid";
+        case MD_ACME_ORDER_ST_INVALID:
+            return "invalid";
+        default:
+            return "invalid";
+    }
+}
+
+md_json_t *md_acme_order_to_json(md_acme_order_t *order, apr_pool_t *p)
+{
+    md_json_t *json = md_json_create(p);
+
+    if (order->url) {
+        md_json_sets(order->url, json, MD_KEY_URL, NULL);
+    }
+    md_json_sets(order_st_to_str(order->status), json, MD_KEY_STATUS, NULL);
+    md_json_setsa(order->authz_urls, json, MD_KEY_AUTHORIZATIONS, NULL);
+    md_json_setsa(order->challenge_setups, json, MD_KEY_CHALLENGE_SETUPS, NULL);
+    if (order->finalize) {
+        md_json_sets(order->finalize, json, MD_KEY_FINALIZE, NULL);
+    }
+    if (order->certificate) {
+        md_json_sets(order->certificate, json, MD_KEY_CERTIFICATE, NULL);
+    }
+    return json;
+}
+
+static void order_update_from_json(md_acme_order_t *order, md_json_t *json, apr_pool_t *p)
+{
+    if (!order->url && md_json_has_key(json, MD_KEY_URL, NULL)) {
+        order->url = md_json_dups(p, json, MD_KEY_URL, NULL);
+    }
+    order->status = order_st_from_str(md_json_gets(json, MD_KEY_STATUS, NULL));
+    if (md_json_has_key(json, MD_KEY_AUTHORIZATIONS, NULL)) {
+        md_json_dupsa(order->authz_urls, p, json, MD_KEY_AUTHORIZATIONS, NULL);
+    }
+    if (md_json_has_key(json, MD_KEY_CHALLENGE_SETUPS, NULL)) {
+        md_json_dupsa(order->challenge_setups, p, json, MD_KEY_CHALLENGE_SETUPS, NULL);
+    }
+    if (md_json_has_key(json, MD_KEY_FINALIZE, NULL)) {
+        order->finalize = md_json_dups(p, json, MD_KEY_FINALIZE, NULL);
+    }
+    if (md_json_has_key(json, MD_KEY_CERTIFICATE, NULL)) {
+        order->certificate = md_json_dups(p, json, MD_KEY_CERTIFICATE, NULL);
+    }
+}
+
+md_acme_order_t *md_acme_order_from_json(md_json_t *json, apr_pool_t *p)
+{
+    md_acme_order_t *order = md_acme_order_create(p);
+
+    order_update_from_json(order, json, p);
+    return order;
+}
+
+apr_status_t md_acme_order_add(md_acme_order_t *order, const char *authz_url)
+{
+    assert(authz_url);
+    if (md_array_str_index(order->authz_urls, authz_url, 0, 1) < 0) {
+        APR_ARRAY_PUSH(order->authz_urls, const char*) = apr_pstrdup(order->p, authz_url);
+    }
+    return APR_SUCCESS;
+}
+
+apr_status_t md_acme_order_remove(md_acme_order_t *order, const char *authz_url)
+{
+    int i;
+    
+    assert(authz_url);
+    i = md_array_str_index(order->authz_urls, authz_url, 0, 1);
+    if (i >= 0) {
+        order->authz_urls = md_array_str_remove(order->p, order->authz_urls, authz_url, 1);
+        return APR_SUCCESS;
+    }
+    return APR_ENOENT;
+}
+
+static apr_status_t add_setup_token(md_acme_order_t *order, const char *token)
+{
+    if (md_array_str_index(order->challenge_setups, token, 0, 1) < 0) {
+        APR_ARRAY_PUSH(order->challenge_setups, const char*) = apr_pstrdup(order->p, token);
+    }
+    return APR_SUCCESS;
+}
+
+/**************************************************************************************************/
+/* persistence */
+
+apr_status_t md_acme_order_load(struct md_store_t *store, md_store_group_t group, 
+                                    const char *md_name, md_acme_order_t **pauthz_set, 
+                                    apr_pool_t *p)
+{
+    apr_status_t rv;
+    md_json_t *json;
+    md_acme_order_t *authz_set;
+    
+    rv = md_store_load_json(store, group, md_name, MD_FN_ORDER, &json, p);
+    if (APR_SUCCESS == rv) {
+        authz_set = md_acme_order_from_json(json, p);
+    }
+    *pauthz_set = (APR_SUCCESS == rv)? authz_set : NULL;
+    return rv;  
+}
+
+static apr_status_t p_save(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_t *store = baton;
+    md_json_t *json;
+    md_store_group_t group;
+    md_acme_order_t *set;
+    const char *md_name;
+    int create;
+ 
+    (void)p;   
+    group = (md_store_group_t)va_arg(ap, int);
+    md_name = va_arg(ap, const char *);
+    set = va_arg(ap, md_acme_order_t *);
+    create = va_arg(ap, int);
+
+    json = md_acme_order_to_json(set, ptemp);
+    assert(json);
+    return md_store_save_json(store, ptemp, group, md_name, MD_FN_ORDER, json, create);
+}
+
+apr_status_t md_acme_order_save(struct md_store_t *store, apr_pool_t *p,
+                                    md_store_group_t group, const char *md_name, 
+                                    md_acme_order_t *authz_set, int create)
+{
+    return md_util_pool_vdo(p_save, store, p, group, md_name, authz_set, create, NULL);
+}
+
+static apr_status_t p_purge(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_t *store = baton;
+    md_acme_order_t *order;
+    md_store_group_t group;
+    const md_t *md;
+    const char *setup_token;
+    apr_table_t *env;
+    int i;
+
+    group = (md_store_group_t)va_arg(ap, int);
+    md = va_arg(ap, const md_t *);
+    env = va_arg(ap, apr_table_t *);
+
+    if (APR_SUCCESS == md_acme_order_load(store, group, md->name, &order, p)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, "order loaded for %s", md->name);
+        for (i = 0; i < order->challenge_setups->nelts; ++i) {
+            setup_token = APR_ARRAY_IDX(order->challenge_setups, i, const char*);
+            if (setup_token) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, 
+                              "order teardown setup %s", setup_token);
+                md_acme_authz_teardown(store, setup_token, md, env, p);
+            }
+        }
+    }
+    return md_store_remove(store, group, md->name, MD_FN_ORDER, ptemp, 1);
+}
+
+apr_status_t md_acme_order_purge(md_store_t *store, apr_pool_t *p, md_store_group_t group,
+                                 const md_t *md, apr_table_t *env)
+{
+    return md_util_pool_vdo(p_purge, store, p, group, md, env, NULL);
+}
+
+/**************************************************************************************************/
+/* ACMEv2 order requests */
+
+typedef struct {
+    apr_pool_t *p;
+    md_acme_order_t *order;
+    md_acme_t *acme;
+    const char *name;
+    apr_array_header_t *domains;
+    md_result_t *result;
+} order_ctx_t;
+
+#define ORDER_CTX_INIT(ctx, p, o, a, n, d, r) \
+    (ctx)->p = (p); (ctx)->order = (o); (ctx)->acme = (a); \
+    (ctx)->name = (n); (ctx)->domains = d; (ctx)->result = r
+
+static apr_status_t identifier_to_json(void *value, md_json_t *json, apr_pool_t *p, void *baton)
+{
+    md_json_t *jid;
+    
+    (void)baton;
+    jid = md_json_create(p);
+    md_json_sets("dns", jid, "type", NULL);
+    md_json_sets(value, jid, "value", NULL);
+    return md_json_setj(jid, json, NULL);
+}
+
+static apr_status_t on_init_order_register(md_acme_req_t *req, void *baton)
+{
+    order_ctx_t *ctx = baton;
+    md_json_t *jpayload;
+
+    jpayload = md_json_create(req->p);
+    md_json_seta(ctx->domains, identifier_to_json, NULL, jpayload, "identifiers", NULL);
+
+    return md_acme_req_body_init(req, jpayload);
+} 
+
+static apr_status_t on_order_upd(md_acme_t *acme, apr_pool_t *p, const apr_table_t *hdrs, 
+                                 md_json_t *body, void *baton)
+{
+    order_ctx_t *ctx = baton;
+    const char *location = apr_table_get(hdrs, "location");
+    apr_status_t rv = APR_SUCCESS;
+    
+    (void)acme;
+    (void)p;
+    if (!ctx->order) {
+        if (location) {
+            ctx->order = md_acme_order_create(ctx->p);
+            ctx->order->url = apr_pstrdup(ctx->p, location);
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, ctx->p, "new order at %s", location);
+        }
+        else {
+            rv = APR_EINVAL;
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, ctx->p, "new order, no location header");
+            goto out;
+        }
+    }
+    
+    order_update_from_json(ctx->order, body, ctx->p);
+out:
+    return rv;
+}
+
+apr_status_t md_acme_order_register(md_acme_order_t **porder, md_acme_t *acme, apr_pool_t *p, 
+                                    const char *name, apr_array_header_t *domains)
+{
+    order_ctx_t ctx;
+    apr_status_t rv;
+    
+    assert(MD_ACME_VERSION_MAJOR(acme->version) > 1);
+    ORDER_CTX_INIT(&ctx, p, NULL, acme, name, domains, NULL);
+    rv = md_acme_POST(acme, acme->api.v2.new_order, on_init_order_register, on_order_upd, NULL, NULL, &ctx);
+    *porder = (APR_SUCCESS == rv)? ctx.order : NULL;
+    return rv;
+}
+
+apr_status_t md_acme_order_update(md_acme_order_t *order, md_acme_t *acme, 
+                                  md_result_t *result, apr_pool_t *p)
+{
+    order_ctx_t ctx;
+    apr_status_t rv;
+    
+    assert(MD_ACME_VERSION_MAJOR(acme->version) > 1);
+    ORDER_CTX_INIT(&ctx, p, order, acme, NULL, NULL, result);
+    rv = md_acme_GET(acme, order->url, NULL, on_order_upd, NULL, NULL, &ctx);
+    if (APR_SUCCESS != rv && APR_SUCCESS != acme->last->status) {
+        md_result_dup(result, acme->last);
+    }
+    return rv;
+}
+
+static apr_status_t await_ready(void *baton, int attempt)
+{
+    order_ctx_t *ctx = baton;
+    apr_status_t rv = APR_SUCCESS;
+    
+    (void)attempt;
+    if (APR_SUCCESS != (rv = md_acme_order_update(ctx->order, ctx->acme,
+                                                  ctx->result, ctx->p))) goto out;
+    switch (ctx->order->status) {
+        case MD_ACME_ORDER_ST_READY:
+        case MD_ACME_ORDER_ST_PROCESSING:
+        case MD_ACME_ORDER_ST_VALID:
+            break;
+        case MD_ACME_ORDER_ST_PENDING:
+            rv = APR_EAGAIN;
+            break;
+        default:
+            rv = APR_EINVAL;
+            break;
+    }
+out:    
+    return rv;
+}
+
+apr_status_t md_acme_order_await_ready(md_acme_order_t *order, md_acme_t *acme, 
+                                       const md_t *md, apr_interval_time_t timeout, 
+                                       md_result_t *result, apr_pool_t *p)
+{
+    order_ctx_t ctx;
+    apr_status_t rv;
+    
+    assert(MD_ACME_VERSION_MAJOR(acme->version) > 1);
+    ORDER_CTX_INIT(&ctx, p, order, acme, md->name, NULL, result);
+
+    md_result_activity_setn(result, "Waiting for order to become ready");
+    rv = md_util_try(await_ready, &ctx, 0, timeout, 0, 0, 1);
+    md_result_log(result, MD_LOG_DEBUG);
+    return rv;
+}
+
+static apr_status_t await_valid(void *baton, int attempt)
+{
+    order_ctx_t *ctx = baton;
+    apr_status_t rv = APR_SUCCESS;
+
+    (void)attempt;
+    if (APR_SUCCESS != (rv = md_acme_order_update(ctx->order, ctx->acme, 
+                                                  ctx->result, ctx->p))) goto out;
+    switch (ctx->order->status) {
+        case MD_ACME_ORDER_ST_VALID:
+            md_result_set(ctx->result, APR_EINVAL, "ACME server order status is 'valid'.");
+            break;
+        case MD_ACME_ORDER_ST_PROCESSING:
+            rv = APR_EAGAIN;
+            break;
+        case MD_ACME_ORDER_ST_INVALID:
+            md_result_set(ctx->result, APR_EINVAL, "ACME server order status is 'invalid'.");
+            rv = APR_EINVAL;
+            break;
+        default:
+            rv = APR_EINVAL;
+            break;
+    }
+out:    
+    return rv;
+}
+
+apr_status_t md_acme_order_await_valid(md_acme_order_t *order, md_acme_t *acme, 
+                                       const md_t *md, apr_interval_time_t timeout, 
+                                       md_result_t *result, apr_pool_t *p)
+{
+    order_ctx_t ctx;
+    apr_status_t rv;
+    
+    assert(MD_ACME_VERSION_MAJOR(acme->version) > 1);
+    ORDER_CTX_INIT(&ctx, p, order, acme, md->name, NULL, result);
+
+    md_result_activity_setn(result, "Waiting for finalized order to become valid");
+    rv = md_util_try(await_valid, &ctx, 0, timeout, 0, 0, 1);
+    md_result_log(result, MD_LOG_DEBUG);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* processing */
+
+apr_status_t md_acme_order_start_challenges(md_acme_order_t *order, md_acme_t *acme, 
+                                            apr_array_header_t *challenge_types,
+                                            md_store_t *store, const md_t *md, 
+                                            apr_table_t *env, md_result_t *result, 
+                                            apr_pool_t *p)
+{
+    apr_status_t rv = APR_SUCCESS;
+    md_acme_authz_t *authz;
+    const char *url, *setup_token;
+    int i;
+    
+    md_result_activity_printf(result, "Starting challenges for domains");
+    for (i = 0; i < order->authz_urls->nelts; ++i) {
+        url = APR_ARRAY_IDX(order->authz_urls, i, const char*);
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "%s: check AUTHZ at %s", md->name, url);
+        
+        if (APR_SUCCESS != (rv = md_acme_authz_retrieve(acme, p, url, &authz))) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "%s: check authz for %s",
+                          md->name, authz->domain);
+            goto leave;
+        }
+
+        switch (authz->state) {
+            case MD_ACME_AUTHZ_S_VALID:
+                break;
+                
+            case MD_ACME_AUTHZ_S_PENDING:
+                md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p,
+                              "%s: authorization pending for %s",
+                              md->name, authz->domain);
+                rv = md_acme_authz_respond(authz, acme, store, challenge_types,
+                                           md->pks,
+                                           md->acme_tls_1_domains, md,
+                                           env, p, &setup_token, result);
+                if (APR_SUCCESS != rv) {
+                    goto leave;
+                }
+                add_setup_token(order, setup_token);
+                md_acme_order_save(store, p, MD_SG_STAGING, md->name, order, 0);
+                break;
+                
+            case MD_ACME_AUTHZ_S_INVALID:
+                rv = APR_EINVAL;
+                if (authz->error_type) {
+                    md_result_problem_set(result, rv, authz->error_type, authz->error_detail, NULL);
+                    goto leave;
+                }
+                /* fall through */
+            default:
+                rv = APR_EINVAL;
+                md_result_printf(result, rv, "unexpected AUTHZ state %d for domain %s", 
+                                 authz->state, authz->domain);
+                md_result_log(result, MD_LOG_ERR);
+                goto leave;
+        }
+    }
+leave:    
+    return rv;
+}
+
+static apr_status_t check_challenges(void *baton, int attempt)
+{
+    order_ctx_t *ctx = baton;
+    const char *url;
+    md_acme_authz_t *authz;
+    apr_status_t rv = APR_SUCCESS;
+    int i;
+    
+    for (i = 0; i < ctx->order->authz_urls->nelts; ++i) {
+        url = APR_ARRAY_IDX(ctx->order->authz_urls, i, const char*);
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, ctx->p, "%s: check AUTHZ at %s (attempt %d)", 
+                      ctx->name, url, attempt);
+        
+        rv = md_acme_authz_retrieve(ctx->acme, ctx->p, url, &authz);
+        if (APR_SUCCESS == rv) {
+            switch (authz->state) {
+                case MD_ACME_AUTHZ_S_VALID:
+                    md_result_printf(ctx->result, rv, 
+                                     "domain authorization for %s is valid", authz->domain);
+                    break;
+                case MD_ACME_AUTHZ_S_PENDING:
+                    rv = APR_EAGAIN;
+                    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, ctx->p, 
+                                  "%s: status pending at %s", authz->domain, authz->url);
+                    goto leave;
+                case MD_ACME_AUTHZ_S_INVALID:
+                    rv = APR_EINVAL;
+                    md_result_printf(ctx->result, rv,
+                                     "domain authorization for %s failed, CA considers "
+                                     "answer to challenge invalid%s.",
+                                     authz->domain, authz->error_type? "" : ", no error given");
+                    md_result_log(ctx->result, MD_LOG_ERR);
+                    goto leave;
+                default:
+                    rv = APR_EINVAL;
+                    md_result_printf(ctx->result, rv, 
+                                     "domain authorization for %s failed with state %d", 
+                                     authz->domain, authz->state);
+                    md_result_log(ctx->result, MD_LOG_ERR);
+                    goto leave;
+            }
+        }
+        else {
+            md_result_printf(ctx->result, rv, "authorization retrieval failed for domain %s", 
+                             authz->domain);
+        }
+    }
+leave:
+    return rv;
+}
+
+apr_status_t md_acme_order_monitor_authzs(md_acme_order_t *order, md_acme_t *acme, 
+                                          const md_t *md, apr_interval_time_t timeout, 
+                                          md_result_t *result, apr_pool_t *p)
+{
+    order_ctx_t ctx;
+    apr_status_t rv;
+    
+    ORDER_CTX_INIT(&ctx, p, order, acme, md->name, NULL, result);
+    
+    md_result_activity_printf(result, "Monitoring challenge status for %s", md->name);
+    rv = md_util_try(check_challenges, &ctx, 0, timeout, 0, 0, 1);
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "%s: checked authorizations", md->name);
+    return rv;
+}
+
diff --git a/modules/md/md_acme_order.h b/modules/md/md_acme_order.h
new file mode 100644
index 0000000..4170440
--- /dev/null
+++ b/modules/md/md_acme_order.h
@@ -0,0 +1,91 @@
+/* Copyright 2019 greenbytes GmbH (https://www.greenbytes.de)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef md_acme_order_h
+#define md_acme_order_h
+
+struct md_json_t;
+struct md_result_t;
+
+typedef struct md_acme_order_t md_acme_order_t;
+
+typedef enum {
+    MD_ACME_ORDER_ST_PENDING,
+    MD_ACME_ORDER_ST_READY,
+    MD_ACME_ORDER_ST_PROCESSING,
+    MD_ACME_ORDER_ST_VALID,
+    MD_ACME_ORDER_ST_INVALID,
+} md_acme_order_st;
+
+struct md_acme_order_t {
+    apr_pool_t *p;
+    const char *url;
+    md_acme_order_st status;
+    struct apr_array_header_t *authz_urls;
+    struct apr_array_header_t *challenge_setups;
+    struct md_json_t *json;
+    const char *finalize;
+    const char *certificate;
+};
+
+#define MD_FN_ORDER             "order.json"
+
+/**************************************************************************************************/
+
+md_acme_order_t *md_acme_order_create(apr_pool_t *p);
+
+apr_status_t md_acme_order_add(md_acme_order_t *order, const char *authz_url);
+apr_status_t md_acme_order_remove(md_acme_order_t *order, const char *authz_url);
+
+struct md_json_t *md_acme_order_to_json(md_acme_order_t *set, apr_pool_t *p);
+md_acme_order_t *md_acme_order_from_json(struct md_json_t *json, apr_pool_t *p);
+
+apr_status_t md_acme_order_load(struct md_store_t *store, md_store_group_t group, 
+                                    const char *md_name, md_acme_order_t **pauthz_set, 
+                                    apr_pool_t *p);
+apr_status_t md_acme_order_save(struct md_store_t *store, apr_pool_t *p, 
+                                    md_store_group_t group, const char *md_name, 
+                                    md_acme_order_t *authz_set, int create);
+
+apr_status_t md_acme_order_purge(struct md_store_t *store, apr_pool_t *p, 
+                                 md_store_group_t group, const md_t *md,
+                                 apr_table_t *env);
+
+apr_status_t md_acme_order_start_challenges(md_acme_order_t *order, md_acme_t *acme,
+                                            apr_array_header_t *challenge_types,
+                                            md_store_t *store, const md_t *md, 
+                                            apr_table_t *env, struct md_result_t *result,
+                                            apr_pool_t *p);
+
+apr_status_t md_acme_order_monitor_authzs(md_acme_order_t *order, md_acme_t *acme, 
+                                          const md_t *md, apr_interval_time_t timeout,
+                                          struct md_result_t *result, apr_pool_t *p);
+
+/* ACMEv2 only ************************************************************************************/
+
+apr_status_t md_acme_order_register(md_acme_order_t **porder, md_acme_t *acme, apr_pool_t *p, 
+                                    const char *name, struct apr_array_header_t *domains);
+
+apr_status_t md_acme_order_update(md_acme_order_t *order, md_acme_t *acme, 
+                                  struct md_result_t *result, apr_pool_t *p);
+
+apr_status_t md_acme_order_await_ready(md_acme_order_t *order, md_acme_t *acme, 
+                                       const md_t *md, apr_interval_time_t timeout, 
+                                       struct md_result_t *result, apr_pool_t *p);
+apr_status_t md_acme_order_await_valid(md_acme_order_t *order, md_acme_t *acme, 
+                                       const md_t *md, apr_interval_time_t timeout, 
+                                       struct md_result_t *result, apr_pool_t *p);
+
+#endif /* md_acme_order_h */
diff --git a/modules/md/md_acmev2_drive.c b/modules/md/md_acmev2_drive.c
new file mode 100644
index 0000000..9dfca96
--- /dev/null
+++ b/modules/md/md_acmev2_drive.c
@@ -0,0 +1,181 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_buckets.h>
+#include <apr_hash.h>
+#include <apr_uri.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_jws.h"
+#include "md_http.h"
+#include "md_log.h"
+#include "md_result.h"
+#include "md_reg.h"
+#include "md_store.h"
+#include "md_util.h"
+
+#include "md_acme.h"
+#include "md_acme_acct.h"
+#include "md_acme_authz.h"
+#include "md_acme_order.h"
+
+#include "md_acme_drive.h"
+#include "md_acmev2_drive.h"
+
+
+
+/**************************************************************************************************/
+/* order setup */
+
+/**
+ * Either we have an order stored in the STAGING area, or we need to create a 
+ * new one at the ACME server.
+ */
+static apr_status_t ad_setup_order(md_proto_driver_t *d, md_result_t *result, int *pis_new)
+{
+    md_acme_driver_t *ad = d->baton;
+    apr_status_t rv;
+    md_t *md = ad->md;
+    
+    assert(ad->md);
+    assert(ad->acme);
+
+    /* For each domain in MD: AUTHZ setup
+     * if an AUTHZ resource is known, check if it is still valid
+     * if known AUTHZ resource is not valid, remove, goto 4.1.1
+     * if no AUTHZ available, create a new one for the domain, store it
+     */
+    if (pis_new) *pis_new = 0;
+    rv = md_acme_order_load(d->store, MD_SG_STAGING, md->name, &ad->order, d->p);
+    if (APR_SUCCESS == rv) {
+        md_result_activity_setn(result, "Loaded order from staging");
+        goto leave;
+    }
+    else if (!APR_STATUS_IS_ENOENT(rv)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, d->p, "%s: loading order", md->name);
+        md_acme_order_purge(d->store, d->p, MD_SG_STAGING, md, d->env);
+    }
+    
+    md_result_activity_setn(result, "Creating new order");
+    rv = md_acme_order_register(&ad->order, ad->acme, d->p, d->md->name, ad->domains);
+    if (APR_SUCCESS !=rv) goto leave;
+    rv = md_acme_order_save(d->store, d->p, MD_SG_STAGING, d->md->name, ad->order, 0);
+    if (APR_SUCCESS != rv) {
+        md_result_set(result, rv, "saving order in staging");
+    }
+    if (pis_new) *pis_new = 1;
+
+leave:
+    md_acme_report_result(ad->acme, rv, result);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* ACMEv2 renewal */
+
+apr_status_t md_acmev2_drive_renew(md_acme_driver_t *ad, md_proto_driver_t *d, md_result_t *result)
+{
+    apr_status_t rv = APR_SUCCESS;
+    int is_new_order = 0;
+
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: (ACMEv2) need certificate", d->md->name);
+    
+    /* Chose (or create) and ACME account to use */
+    rv = md_acme_drive_set_acct(d, result);
+    if (APR_SUCCESS != rv) goto leave;
+
+    if (!md_array_is_empty(ad->cred->chain)) goto leave;
+        
+    /* ACMEv2 strategy:
+     * 1. load an md_acme_order_t from STAGING, if present
+     * 2. if no order found, register a new order at ACME server
+     * 3. update the order from the server
+     * 4. Switch order state:
+     *   * PENDING: process authz challenges
+     *   * READY: finalize the order
+     *   * PROCESSING: wait and re-assses later
+     *   * VALID: retrieve certificate
+     *   * COMPLETE: all done, return success
+     *   * INVALID and otherwise: fail renewal, delete local order
+     */
+    if (APR_SUCCESS != (rv = ad_setup_order(d, result, &is_new_order))) {
+        goto leave;
+    }
+    
+    rv = md_acme_order_update(ad->order, ad->acme, result, d->p);
+    if (APR_STATUS_IS_ENOENT(rv)
+        || APR_STATUS_IS_EACCES(rv)
+        || MD_ACME_ORDER_ST_INVALID == ad->order->status) {
+        /* order is invalid or no longer known at the ACME server */
+        ad->order = NULL;
+        md_acme_order_purge(d->store, d->p, MD_SG_STAGING, d->md, d->env);
+    }
+    else if (APR_SUCCESS != rv) {
+        goto leave;
+    }
+
+retry:
+    if (!ad->order) {
+        rv = ad_setup_order(d, result, &is_new_order);
+        if (APR_SUCCESS != rv) goto leave;
+    }
+    
+    rv = md_acme_order_start_challenges(ad->order, ad->acme, ad->ca_challenges,
+                                        d->store, d->md, d->env, result, d->p);
+    if (!is_new_order && APR_STATUS_IS_EINVAL(rv)) {
+        /* found 'invalid' domains in previous order, need to start over */
+        ad->order = NULL;
+        md_acme_order_purge(d->store, d->p, MD_SG_STAGING, d->md, d->env);
+        goto retry;
+    }
+    if (APR_SUCCESS != rv) goto leave;
+    
+    rv = md_acme_order_monitor_authzs(ad->order, ad->acme, d->md,
+                                      ad->authz_monitor_timeout, result, d->p);
+    if (APR_SUCCESS != rv) goto leave;
+
+    rv = md_acme_order_await_ready(ad->order, ad->acme, d->md,
+                                   ad->authz_monitor_timeout, result, d->p);
+    if (APR_SUCCESS != rv) goto leave;
+
+    if (MD_ACME_ORDER_ST_READY == ad->order->status) {
+        rv = md_acme_drive_setup_cred_chain(d, result);
+        if (APR_SUCCESS != rv) goto leave;
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: finalized order", d->md->name);
+    }
+
+    rv = md_acme_order_await_valid(ad->order, ad->acme, d->md, 
+                                   ad->authz_monitor_timeout, result, d->p);
+    if (APR_SUCCESS != rv) goto leave;
+    
+    if (!ad->order->certificate) {
+        md_result_set(result, APR_EINVAL, "Order valid, but certificate url is missing.");
+        goto leave;
+    }
+    md_result_set(result, APR_SUCCESS, NULL);
+
+leave:    
+    md_result_log(result, MD_LOG_DEBUG);
+    return result->status;
+}
+
diff --git a/modules/md/md_acmev2_drive.h b/modules/md/md_acmev2_drive.h
new file mode 100644
index 0000000..7552c4f
--- /dev/null
+++ b/modules/md/md_acmev2_drive.h
@@ -0,0 +1,27 @@
+/* Copyright 2019 greenbytes GmbH (https://www.greenbytes.de)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef md_acmev2_drive_h
+#define md_acmev2_drive_h
+
+struct md_json_t;
+struct md_proto_driver_t;
+struct md_result_t;
+
+apr_status_t md_acmev2_drive_renew(struct md_acme_driver_t *ad, 
+                                   struct md_proto_driver_t *d,
+                                   struct md_result_t *result);
+
+#endif /* md_acmev2_drive_h */
diff --git a/modules/md/md_core.c b/modules/md/md_core.c
new file mode 100644
index 0000000..7aacff0
--- /dev/null
+++ b/modules/md/md_core.c
@@ -0,0 +1,462 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_uri.h>
+#include <apr_tables.h>
+#include <apr_time.h>
+#include <apr_date.h>
+
+#include "md_json.h"
+#include "md.h"
+#include "md_crypt.h"
+#include "md_log.h"
+#include "md_store.h"
+#include "md_util.h"
+
+
+int md_contains(const md_t *md, const char *domain, int case_sensitive)
+{
+    if (md_array_str_index(md->domains, domain, 0, case_sensitive) >= 0) {
+        return 1;
+    }
+    return md_dns_domains_match(md->domains, domain);
+}
+
+const char *md_common_name(const md_t *md1, const md_t *md2)
+{
+    int i;
+    
+    if (md1 == NULL || md1->domains == NULL
+        || md2 == NULL || md2->domains == NULL) {
+        return NULL;
+    }
+    
+    for (i = 0; i < md1->domains->nelts; ++i) {
+        const char *name1 = APR_ARRAY_IDX(md1->domains, i, const char*);
+        if (md_contains(md2, name1, 0)) {
+            return name1;
+        }
+    }
+    return NULL;
+}
+
+int md_domains_overlap(const md_t *md1, const md_t *md2)
+{
+    return md_common_name(md1, md2) != NULL;
+}
+
+apr_size_t md_common_name_count(const md_t *md1, const md_t *md2)
+{
+    int i;
+    apr_size_t hits;
+    
+    if (md1 == NULL || md1->domains == NULL
+        || md2 == NULL || md2->domains == NULL) {
+        return 0;
+    }
+    
+    hits = 0;
+    for (i = 0; i < md1->domains->nelts; ++i) {
+        const char *name1 = APR_ARRAY_IDX(md1->domains, i, const char*);
+        if (md_contains(md2, name1, 0)) {
+            ++hits;
+        }
+    }
+    return hits;
+}
+
+int md_is_covered_by_alt_names(const md_t *md, const struct apr_array_header_t* alt_names)
+{
+    const char *name;
+    int i;
+    
+    if (alt_names) {
+        for (i = 0; i < md->domains->nelts; ++i) {
+            name = APR_ARRAY_IDX(md->domains, i, const char *);
+            if (!md_dns_domains_match(alt_names, name)) {
+                return 0;
+            }
+        }
+        return 1;
+    }
+    return 0;
+}
+
+md_t *md_create_empty(apr_pool_t *p)
+{
+    md_t *md = apr_pcalloc(p, sizeof(*md));
+    if (md) {
+        md->domains = apr_array_make(p, 5, sizeof(const char *));
+        md->contacts = apr_array_make(p, 5, sizeof(const char *));
+        md->renew_mode = MD_RENEW_DEFAULT;
+        md->require_https = MD_REQUIRE_UNSET;
+        md->must_staple = -1;
+        md->transitive = -1;
+        md->acme_tls_1_domains = apr_array_make(p, 5, sizeof(const char *));
+        md->stapling = -1;
+        md->defn_name = "unknown";
+        md->defn_line_number = 0;
+    }
+    return md;
+}
+
+int md_equal_domains(const md_t *md1, const md_t *md2, int case_sensitive)
+{
+    int i;
+    if (md1->domains->nelts == md2->domains->nelts) {
+        for (i = 0; i < md1->domains->nelts; ++i) {
+            const char *name1 = APR_ARRAY_IDX(md1->domains, i, const char*);
+            if (!md_contains(md2, name1, case_sensitive)) {
+                return 0;
+            }
+        }
+        return 1;
+    }
+    return 0;
+}
+
+int md_contains_domains(const md_t *md1, const md_t *md2)
+{
+    int i;
+    if (md1->domains->nelts >= md2->domains->nelts) {
+        for (i = 0; i < md2->domains->nelts; ++i) {
+            const char *name2 = APR_ARRAY_IDX(md2->domains, i, const char*);
+            if (!md_contains(md1, name2, 0)) {
+                return 0;
+            }
+        }
+        return 1;
+    }
+    return 0;
+}
+
+md_t *md_get_by_name(struct apr_array_header_t *mds, const char *name)
+{
+    int i;
+    for (i = 0; i < mds->nelts; ++i) {
+        md_t *md = APR_ARRAY_IDX(mds, i, md_t *);
+        if (!strcmp(name, md->name)) {
+            return md;
+        }
+    }
+    return NULL;
+}
+
+md_t *md_get_by_domain(struct apr_array_header_t *mds, const char *domain)
+{
+    int i;
+    for (i = 0; i < mds->nelts; ++i) {
+        md_t *md = APR_ARRAY_IDX(mds, i, md_t *);
+        if (md_contains(md, domain, 0)) {
+            return md;
+        }
+    }
+    return NULL;
+}
+
+md_t *md_get_by_dns_overlap(struct apr_array_header_t *mds, const md_t *md)
+{
+    int i;
+    for (i = 0; i < mds->nelts; ++i) {
+        md_t *o = APR_ARRAY_IDX(mds, i, md_t *);
+        if (strcmp(o->name, md->name) && md_common_name(o, md)) {
+            return o;
+        }
+    }
+    return NULL;
+}
+
+int md_cert_count(const md_t *md)
+{
+    /* cert are defined as a list of static files or a list of private key specs */
+    if (md->cert_files && md->cert_files->nelts) {
+        return md->cert_files->nelts;
+    }
+    return md_pkeys_spec_count(md->pks);
+}
+
+md_t *md_create(apr_pool_t *p, apr_array_header_t *domains)
+{
+    md_t *md;
+    
+    md = md_create_empty(p);
+    md->domains = md_array_str_compact(p, domains, 0);
+    md->name = APR_ARRAY_IDX(md->domains, 0, const char *);
+    
+    return md;
+}
+
+/**************************************************************************************************/
+/* lifetime */
+
+md_t *md_copy(apr_pool_t *p, const md_t *src)
+{
+    md_t *md;
+    
+    md = apr_pcalloc(p, sizeof(*md));
+    if (md) {
+        memcpy(md, src, sizeof(*md));
+        md->domains = apr_array_copy(p, src->domains);
+        md->contacts = apr_array_copy(p, src->contacts);
+        if (src->ca_challenges) {
+            md->ca_challenges = apr_array_copy(p, src->ca_challenges);
+        }
+        md->acme_tls_1_domains = apr_array_copy(p, src->acme_tls_1_domains);
+        md->pks = md_pkeys_spec_clone(p, src->pks);
+    }    
+    return md;   
+}
+
+md_t *md_clone(apr_pool_t *p, const md_t *src)
+{
+    md_t *md;
+    
+    md = apr_pcalloc(p, sizeof(*md));
+    if (md) {
+        md->state = src->state;
+        md->name = apr_pstrdup(p, src->name);
+        md->require_https = src->require_https;
+        md->must_staple = src->must_staple;
+        md->renew_mode = src->renew_mode;
+        md->domains = md_array_str_compact(p, src->domains, 0);
+        md->pks = md_pkeys_spec_clone(p, src->pks);
+        md->renew_window = src->renew_window;
+        md->warn_window = src->warn_window;
+        md->contacts = md_array_str_clone(p, src->contacts);
+        if (src->ca_proto) md->ca_proto = apr_pstrdup(p, src->ca_proto);
+        if (src->ca_urls) {
+            md->ca_urls = md_array_str_clone(p, src->ca_urls);
+        }
+        if (src->ca_effective) md->ca_effective = apr_pstrdup(p, src->ca_effective);
+        if (src->ca_account) md->ca_account = apr_pstrdup(p, src->ca_account);
+        if (src->ca_agreement) md->ca_agreement = apr_pstrdup(p, src->ca_agreement);
+        if (src->defn_name) md->defn_name = apr_pstrdup(p, src->defn_name);
+        md->defn_line_number = src->defn_line_number;
+        if (src->ca_challenges) {
+            md->ca_challenges = md_array_str_clone(p, src->ca_challenges);
+        }
+        md->acme_tls_1_domains = md_array_str_compact(p, src->acme_tls_1_domains, 0);
+        md->stapling = src->stapling;
+        if (src->dns01_cmd) md->dns01_cmd = apr_pstrdup(p, src->dns01_cmd);
+        if (src->cert_files) md->cert_files = md_array_str_clone(p, src->cert_files);
+        if (src->pkey_files) md->pkey_files = md_array_str_clone(p, src->pkey_files);
+    }    
+    return md;   
+}
+
+/**************************************************************************************************/
+/* format conversion */
+
+md_json_t *md_to_json(const md_t *md, apr_pool_t *p)
+{
+    md_json_t *json = md_json_create(p);
+    if (json) {
+        apr_array_header_t *domains = md_array_str_compact(p, md->domains, 0);
+        md_json_sets(md->name, json, MD_KEY_NAME, NULL);
+        md_json_setsa(domains, json, MD_KEY_DOMAINS, NULL);
+        md_json_setsa(md->contacts, json, MD_KEY_CONTACTS, NULL);
+        md_json_setl(md->transitive, json, MD_KEY_TRANSITIVE, NULL);
+        md_json_sets(md->ca_account, json, MD_KEY_CA, MD_KEY_ACCOUNT, NULL);
+        md_json_sets(md->ca_proto, json, MD_KEY_CA, MD_KEY_PROTO, NULL);
+        md_json_sets(md->ca_effective, json, MD_KEY_CA, MD_KEY_URL, NULL);
+        if (md->ca_urls && !apr_is_empty_array(md->ca_urls)) {
+            md_json_setsa(md->ca_urls, json, MD_KEY_CA, MD_KEY_URLS, NULL);
+        }
+        md_json_sets(md->ca_agreement, json, MD_KEY_CA, MD_KEY_AGREEMENT, NULL);
+        if (!md_pkeys_spec_is_empty(md->pks)) {
+            md_json_setj(md_pkeys_spec_to_json(md->pks, p), json, MD_KEY_PKEY, NULL);
+        }
+        md_json_setl(md->state, json, MD_KEY_STATE, NULL);
+        if (md->state_descr)
+            md_json_sets(md->state_descr, json, MD_KEY_STATE_DESCR, NULL);
+        md_json_setl(md->renew_mode, json, MD_KEY_RENEW_MODE, NULL);
+        if (md->renew_window)
+            md_json_sets(md_timeslice_format(md->renew_window, p), json, MD_KEY_RENEW_WINDOW, NULL);
+        if (md->warn_window)
+            md_json_sets(md_timeslice_format(md->warn_window, p), json, MD_KEY_WARN_WINDOW, NULL);
+        if (md->ca_challenges && md->ca_challenges->nelts > 0) {
+            apr_array_header_t *na;
+            na = md_array_str_compact(p, md->ca_challenges, 0);
+            md_json_setsa(na, json, MD_KEY_CA, MD_KEY_CHALLENGES, NULL);
+        }
+        switch (md->require_https) {
+            case MD_REQUIRE_TEMPORARY:
+                md_json_sets(MD_KEY_TEMPORARY, json, MD_KEY_REQUIRE_HTTPS, NULL);
+                break;
+            case MD_REQUIRE_PERMANENT:
+                md_json_sets(MD_KEY_PERMANENT, json, MD_KEY_REQUIRE_HTTPS, NULL);
+                break;
+            default:
+                break;
+        }
+        md_json_setb(md->must_staple > 0, json, MD_KEY_MUST_STAPLE, NULL);
+        md_json_setsa(md->acme_tls_1_domains, json, MD_KEY_PROTO, MD_KEY_ACME_TLS_1, NULL);
+        if (md->cert_files) md_json_setsa(md->cert_files, json, MD_KEY_CERT_FILES, NULL);
+        if (md->pkey_files) md_json_setsa(md->pkey_files, json, MD_KEY_PKEY_FILES, NULL);
+        md_json_setb(md->stapling > 0, json, MD_KEY_STAPLING, NULL);
+        if (md->dns01_cmd) md_json_sets(md->dns01_cmd, json, MD_KEY_CMD_DNS01, NULL);
+        if (md->ca_eab_kid && strcmp("none", md->ca_eab_kid)) {
+            md_json_sets(md->ca_eab_kid, json, MD_KEY_EAB, MD_KEY_KID, NULL);
+            if (md->ca_eab_hmac) md_json_sets(md->ca_eab_hmac, json, MD_KEY_EAB, MD_KEY_HMAC, NULL);
+        }
+        return json;
+    }
+    return NULL;
+}
+
+md_t *md_from_json(md_json_t *json, apr_pool_t *p)
+{
+    const char *s;
+    md_t *md = md_create_empty(p);
+    if (md) {
+        md->name = md_json_dups(p, json, MD_KEY_NAME, NULL);            
+        md_json_dupsa(md->domains, p, json, MD_KEY_DOMAINS, NULL);
+        md_json_dupsa(md->contacts, p, json, MD_KEY_CONTACTS, NULL);
+        md->ca_account = md_json_dups(p, json, MD_KEY_CA, MD_KEY_ACCOUNT, NULL);
+        md->ca_proto = md_json_dups(p, json, MD_KEY_CA, MD_KEY_PROTO, NULL);
+        md->ca_effective = md_json_dups(p, json, MD_KEY_CA, MD_KEY_URL, NULL);
+        if (md_json_has_key(json, MD_KEY_CA, MD_KEY_URLS, NULL)) {
+            md->ca_urls = apr_array_make(p, 5, sizeof(const char*));
+            md_json_dupsa(md->ca_urls, p, json, MD_KEY_CA, MD_KEY_URLS, NULL);
+        }
+        else if (md->ca_effective) {
+            /* compat for old format where we had only a single url */
+            md->ca_urls = apr_array_make(p, 5, sizeof(const char*));
+            APR_ARRAY_PUSH(md->ca_urls, const char*) = md->ca_effective;
+        }
+        md->ca_agreement = md_json_dups(p, json, MD_KEY_CA, MD_KEY_AGREEMENT, NULL);
+        if (md_json_has_key(json, MD_KEY_PKEY, NULL)) {
+            md->pks = md_pkeys_spec_from_json(md_json_getj(json, MD_KEY_PKEY, NULL), p);
+        }
+        md->state = (md_state_t)md_json_getl(json, MD_KEY_STATE, NULL);
+        md->state_descr = md_json_dups(p, json, MD_KEY_STATE_DESCR, NULL);
+        if (MD_S_EXPIRED_DEPRECATED == md->state) md->state = MD_S_COMPLETE;
+        md->renew_mode = (int)md_json_getl(json, MD_KEY_RENEW_MODE, NULL);
+        md->domains = md_array_str_compact(p, md->domains, 0);
+        md->transitive = (int)md_json_getl(json, MD_KEY_TRANSITIVE, NULL);
+        s = md_json_gets(json, MD_KEY_RENEW_WINDOW, NULL);
+        md_timeslice_parse(&md->renew_window, p, s, MD_TIME_LIFE_NORM);
+        s = md_json_gets(json, MD_KEY_WARN_WINDOW, NULL);
+        md_timeslice_parse(&md->warn_window, p, s, MD_TIME_LIFE_NORM);
+        if (md_json_has_key(json, MD_KEY_CA, MD_KEY_CHALLENGES, NULL)) {
+            md->ca_challenges = apr_array_make(p, 5, sizeof(const char*));
+            md_json_dupsa(md->ca_challenges, p, json, MD_KEY_CA, MD_KEY_CHALLENGES, NULL);
+        }
+        md->require_https = MD_REQUIRE_OFF;
+        s = md_json_gets(json, MD_KEY_REQUIRE_HTTPS, NULL);
+        if (s && !strcmp(MD_KEY_TEMPORARY, s)) {
+            md->require_https = MD_REQUIRE_TEMPORARY;
+        }
+        else if (s && !strcmp(MD_KEY_PERMANENT, s)) {
+            md->require_https = MD_REQUIRE_PERMANENT;
+        }
+        md->must_staple = (int)md_json_getb(json, MD_KEY_MUST_STAPLE, NULL);
+        md_json_dupsa(md->acme_tls_1_domains, p, json, MD_KEY_PROTO, MD_KEY_ACME_TLS_1, NULL);
+            
+        if (md_json_has_key(json, MD_KEY_CERT_FILES, NULL)) {
+            md->cert_files = apr_array_make(p, 3, sizeof(char*));
+            md->pkey_files = apr_array_make(p, 3, sizeof(char*));
+            md_json_dupsa(md->cert_files, p, json, MD_KEY_CERT_FILES, NULL);
+            md_json_dupsa(md->pkey_files, p, json, MD_KEY_PKEY_FILES, NULL);
+        }
+        md->stapling = (int)md_json_getb(json, MD_KEY_STAPLING, NULL);
+        md->dns01_cmd = md_json_dups(p, json, MD_KEY_CMD_DNS01, NULL);
+        if (md_json_has_key(json, MD_KEY_EAB, NULL)) {
+            md->ca_eab_kid = md_json_dups(p, json, MD_KEY_EAB, MD_KEY_KID, NULL);
+            md->ca_eab_hmac = md_json_dups(p, json, MD_KEY_EAB, MD_KEY_HMAC, NULL);
+        }
+        return md;
+    }
+    return NULL;
+}
+
+md_json_t *md_to_public_json(const md_t *md, apr_pool_t *p)
+{
+    md_json_t *json = md_to_json(md, p);
+    if (md_json_has_key(json, MD_KEY_EAB, MD_KEY_HMAC, NULL)) {
+        md_json_sets("***", json, MD_KEY_EAB, MD_KEY_HMAC, NULL);
+    }
+    return json;
+}
+
+typedef struct {
+    const char *name;
+    const char *url;
+} md_ca_t;
+
+#define LE_ACMEv2_PROD      "https://acme-v02.api.letsencrypt.org/directory"
+#define LE_ACMEv2_STAGING   "https://acme-staging-v02.api.letsencrypt.org/directory"
+#define BUYPASS_ACME        "https://api.buypass.com/acme/directory"
+#define BUYPASS_ACME_TEST   "https://api.test4.buypass.no/acme/directory"
+
+static md_ca_t KNOWN_CAs[] = {
+    { "LetsEncrypt", LE_ACMEv2_PROD },
+    { "LetsEncrypt-Test", LE_ACMEv2_STAGING },
+    { "Buypass", BUYPASS_ACME },
+    { "Buypass-Test", BUYPASS_ACME_TEST },
+};
+
+const char *md_get_ca_name_from_url(apr_pool_t *p, const char *url)
+{
+    apr_uri_t uri_parsed;
+    unsigned int i;
+
+    for (i = 0; i < sizeof(KNOWN_CAs)/sizeof(KNOWN_CAs[0]); ++i) {
+        if (!apr_strnatcasecmp(KNOWN_CAs[i].url, url)) {
+            return KNOWN_CAs[i].name;
+        }
+    }
+    if (APR_SUCCESS == apr_uri_parse(p, url, &uri_parsed)) {
+        return uri_parsed.hostname;
+    }
+    return apr_pstrdup(p, url);
+}
+
+apr_status_t md_get_ca_url_from_name(const char **purl, apr_pool_t *p, const char *name)
+{
+    const char *err;
+    unsigned int i;
+    apr_status_t rv = APR_SUCCESS;
+
+    *purl = NULL;
+    for (i = 0; i < sizeof(KNOWN_CAs)/sizeof(KNOWN_CAs[0]); ++i) {
+        if (!apr_strnatcasecmp(KNOWN_CAs[i].name, name)) {
+            *purl = KNOWN_CAs[i].url;
+            goto leave;
+        }
+    }
+    *purl = name;
+    rv = md_util_abs_uri_check(p, name, &err);
+    if (APR_SUCCESS != rv) {
+        apr_array_header_t *names;
+
+        names = apr_array_make(p, 10, sizeof(const char*));
+        for (i = 0; i < sizeof(KNOWN_CAs)/sizeof(KNOWN_CAs[0]); ++i) {
+            APR_ARRAY_PUSH(names, const char *) = KNOWN_CAs[i].name;
+        }
+        *purl = apr_psprintf(p,
+            "The CA name '%s' is not known and it is not a URL either (%s). "
+            "Known CA names are: %s.",
+            name, err, apr_array_pstrcat(p, names, ' '));
+    }
+leave:
+    return rv;
+}
diff --git a/modules/md/md_crypt.c b/modules/md/md_crypt.c
new file mode 100644
index 0000000..f2b0cd5
--- /dev/null
+++ b/modules/md/md_crypt.c
@@ -0,0 +1,2140 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_buckets.h>
+#include <apr_file_io.h>
+#include <apr_strings.h>
+#include <httpd.h>
+#include <http_core.h>
+
+#include <openssl/err.h>
+#include <openssl/evp.h>
+#include <openssl/hmac.h>
+#include <openssl/pem.h>
+#include <openssl/rand.h>
+#include <openssl/rsa.h>
+#include <openssl/x509v3.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_log.h"
+#include "md_http.h"
+#include "md_time.h"
+#include "md_util.h"
+
+/* getpid for *NIX */
+#if APR_HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#if APR_HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+/* getpid for Windows */
+#if APR_HAVE_PROCESS_H
+#include <process.h>
+#endif
+
+#if defined(LIBRESSL_VERSION_NUMBER)
+/* Missing from LibreSSL */
+#define MD_USE_OPENSSL_PRE_1_1_API (LIBRESSL_VERSION_NUMBER < 0x2070000f)
+#else /* defined(LIBRESSL_VERSION_NUMBER) */
+#define MD_USE_OPENSSL_PRE_1_1_API (OPENSSL_VERSION_NUMBER < 0x10100000L)
+#endif
+
+#if (defined(LIBRESSL_VERSION_NUMBER) && (LIBRESSL_VERSION_NUMBER < 0x3050000fL)) || (OPENSSL_VERSION_NUMBER < 0x10100000L) 
+/* Missing from LibreSSL < 3.5.0 and only available since OpenSSL v1.1.x */
+#ifndef OPENSSL_NO_CT
+#define OPENSSL_NO_CT
+#endif
+#endif
+
+#ifndef OPENSSL_NO_CT
+#include <openssl/ct.h>
+#endif
+
+static int initialized;
+
+struct md_pkey_t {
+    apr_pool_t *pool;
+    EVP_PKEY   *pkey;
+};
+
+#ifdef MD_HAVE_ARC4RANDOM
+
+static void seed_RAND(int pid)
+{
+    char seed[128];
+    
+    (void)pid;
+    arc4random_buf(seed, sizeof(seed));
+    RAND_seed(seed, sizeof(seed));
+}
+
+#else /* ifdef MD_HAVE_ARC4RANDOM */
+
+static int rand_choosenum(int l, int h)
+{
+    int i;
+    char buf[50];
+
+    apr_snprintf(buf, sizeof(buf), "%.0f",
+                 (((double)(rand()%RAND_MAX)/RAND_MAX)*(h-l)));
+    i = atoi(buf)+1;
+    if (i < l) i = l;
+    if (i > h) i = h;
+    return i;
+}
+
+static void seed_RAND(int pid)
+{   
+    unsigned char stackdata[256];
+    /* stolen from mod_ssl/ssl_engine_rand.c */
+    int n;
+    struct {
+        time_t t;
+        pid_t pid;
+    } my_seed;
+    
+    /*
+     * seed in the current time (usually just 4 bytes)
+     */
+    my_seed.t = time(NULL);
+    
+    /*
+     * seed in the current process id (usually just 4 bytes)
+     */
+    my_seed.pid = pid;
+    
+    RAND_seed((unsigned char *)&my_seed, sizeof(my_seed));
+    
+    /*
+     * seed in some current state of the run-time stack (128 bytes)
+     */
+    n = rand_choosenum(0, sizeof(stackdata)-128-1);
+    RAND_seed(stackdata+n, 128);
+}
+
+#endif /*ifdef MD_HAVE_ARC4RANDOM (else part) */
+
+
+apr_status_t md_crypt_init(apr_pool_t *pool)
+{
+    (void)pool;
+    
+    if (!initialized) {
+        int pid = getpid();
+        
+        ERR_load_crypto_strings();
+        OpenSSL_add_all_algorithms();
+        
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, pool, "initializing RAND"); 
+        while (!RAND_status()) {
+            seed_RAND(pid);
+	}
+
+        initialized = 1;
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t fwrite_buffer(void *baton, apr_file_t *f, apr_pool_t *p) 
+{
+    md_data_t *buf = baton;
+    apr_size_t wlen;
+    
+    (void)p;
+    return apr_file_write_full(f, buf->data, buf->len, &wlen);
+}
+
+apr_status_t md_rand_bytes(unsigned char *buf, apr_size_t len, apr_pool_t *p)
+{
+    apr_status_t rv;
+    
+    if (len > INT_MAX) {
+        return APR_ENOTIMPL;
+    }
+    if (APR_SUCCESS == (rv = md_crypt_init(p))) {
+        RAND_bytes((unsigned char*)buf, (int)len);
+    }
+    return rv;
+}
+
+typedef struct {
+    const char *pass_phrase;
+    int pass_len;
+} passwd_ctx;
+
+static int pem_passwd(char *buf, int size, int rwflag, void *baton)
+{
+    passwd_ctx *ctx = baton;
+    
+    (void)rwflag;
+    if (ctx->pass_len > 0) {
+        if (ctx->pass_len < size) {
+            size = (int)ctx->pass_len;
+        }
+        memcpy(buf, ctx->pass_phrase, (size_t)size);
+    } else {
+        return 0;
+    }
+    return size;
+}
+
+/**************************************************************************************************/
+/* date time things */
+
+/* Get the apr time (micro seconds, since 1970) from an ASN1 time, as stored in X509
+ * certificates. OpenSSL now has a utility function, but other *SSL derivatives have
+ * not caughts up yet or chose to ignore. An alternative is implemented, we prefer 
+ * however the *SSL to maintain such things.
+ */
+static apr_time_t md_asn1_time_get(const ASN1_TIME* time)
+{
+#if OPENSSL_VERSION_NUMBER < 0x10002000L || (defined(LIBRESSL_VERSION_NUMBER) && \
+                                             LIBRESSL_VERSION_NUMBER < 0x3060000fL)
+    /* courtesy: https://stackoverflow.com/questions/10975542/asn1-time-to-time-t-conversion#11263731
+     * all bugs are mine */
+    apr_time_exp_t t;
+    apr_time_t ts;
+    const char* str = (const char*) time->data;
+    apr_size_t i = 0;
+
+    memset(&t, 0, sizeof(t));
+
+    if (time->type == V_ASN1_UTCTIME) {/* two digit year */
+        t.tm_year = (str[i++] - '0') * 10;
+        t.tm_year += (str[i++] - '0');
+        if (t.tm_year < 70)
+            t.tm_year += 100;
+    } 
+    else if (time->type == V_ASN1_GENERALIZEDTIME) {/* four digit year */
+        t.tm_year = (str[i++] - '0') * 1000;
+        t.tm_year+= (str[i++] - '0') * 100;
+        t.tm_year+= (str[i++] - '0') * 10;
+        t.tm_year+= (str[i++] - '0');
+        t.tm_year -= 1900;
+    }
+    t.tm_mon  = (str[i++] - '0') * 10;
+    t.tm_mon += (str[i++] - '0') - 1; /* -1 since January is 0 not 1. */
+    t.tm_mday = (str[i++] - '0') * 10;
+    t.tm_mday+= (str[i++] - '0');
+    t.tm_hour = (str[i++] - '0') * 10;
+    t.tm_hour+= (str[i++] - '0');
+    t.tm_min  = (str[i++] - '0') * 10;
+    t.tm_min += (str[i++] - '0');
+    t.tm_sec  = (str[i++] - '0') * 10;
+    t.tm_sec += (str[i++] - '0');
+    
+    if (APR_SUCCESS == apr_time_exp_gmt_get(&ts, &t)) {
+        return ts;
+    }
+    return 0;
+#else 
+    int secs, days;
+    apr_time_t ts = apr_time_now();
+    
+    if (ASN1_TIME_diff(&days, &secs, NULL, time)) {
+        ts += apr_time_from_sec((days * MD_SECS_PER_DAY) + secs); 
+    }
+    return ts;
+#endif
+}
+
+apr_time_t md_asn1_generalized_time_get(void *ASN1_GENERALIZEDTIME)
+{
+    return md_asn1_time_get(ASN1_GENERALIZEDTIME);
+}
+
+/**************************************************************************************************/
+/* OID/NID things */
+
+static int get_nid(const char *num, const char *sname, const char *lname)
+{
+    /* Funny API, an OID for a feature might be configured or
+     * maybe not. In the second case, we need to add it. But adding
+     * when it already is there is an error... */
+    int nid = OBJ_txt2nid(num);
+    if (NID_undef == nid) {
+        nid = OBJ_create(num, sname, lname);
+    }
+    return nid;
+}
+
+#define MD_GET_NID(x)  get_nid(MD_OID_##x##_NUM, MD_OID_##x##_SNAME, MD_OID_##x##_LNAME)
+
+/**************************************************************************************************/
+/* private keys */
+
+md_pkeys_spec_t *md_pkeys_spec_make(apr_pool_t *p)
+{
+    md_pkeys_spec_t *pks;
+    
+    pks = apr_pcalloc(p, sizeof(*pks));
+    pks->p = p;
+    pks->specs = apr_array_make(p, 2, sizeof(md_pkey_spec_t*));
+    return pks;
+}
+
+void md_pkeys_spec_add(md_pkeys_spec_t *pks, md_pkey_spec_t *spec)
+{
+    APR_ARRAY_PUSH(pks->specs, md_pkey_spec_t*) = spec;
+}
+
+void md_pkeys_spec_add_default(md_pkeys_spec_t *pks)
+{
+    md_pkey_spec_t *spec;
+    
+    spec = apr_pcalloc(pks->p, sizeof(*spec));
+    spec->type = MD_PKEY_TYPE_DEFAULT;
+    md_pkeys_spec_add(pks, spec);
+}
+
+int md_pkeys_spec_contains_rsa(md_pkeys_spec_t *pks)
+{
+    md_pkey_spec_t *spec;
+    int i;
+    for (i = 0; i < pks->specs->nelts; ++i) {
+        spec = APR_ARRAY_IDX(pks->specs, i, md_pkey_spec_t*);
+        if (MD_PKEY_TYPE_RSA == spec->type) return 1;   
+    }
+    return 0;
+}
+
+void md_pkeys_spec_add_rsa(md_pkeys_spec_t *pks, unsigned int bits)
+{
+    md_pkey_spec_t *spec;
+    
+    spec = apr_pcalloc(pks->p, sizeof(*spec));
+    spec->type = MD_PKEY_TYPE_RSA;
+    spec->params.rsa.bits = bits;
+    md_pkeys_spec_add(pks, spec);
+}
+
+int md_pkeys_spec_contains_ec(md_pkeys_spec_t *pks, const char *curve)
+{
+    md_pkey_spec_t *spec;
+    int i;
+    for (i = 0; i < pks->specs->nelts; ++i) {
+        spec = APR_ARRAY_IDX(pks->specs, i, md_pkey_spec_t*);
+        if (MD_PKEY_TYPE_EC == spec->type 
+            && !apr_strnatcasecmp(curve, spec->params.ec.curve)) return 1;   
+    }
+    return 0;
+}
+
+void md_pkeys_spec_add_ec(md_pkeys_spec_t *pks, const char *curve)
+{
+    md_pkey_spec_t *spec;
+    
+    spec = apr_pcalloc(pks->p, sizeof(*spec));
+    spec->type = MD_PKEY_TYPE_EC;
+    spec->params.ec.curve = apr_pstrdup(pks->p, curve);
+    md_pkeys_spec_add(pks, spec);
+}
+
+md_json_t *md_pkey_spec_to_json(const md_pkey_spec_t *spec, apr_pool_t *p)
+{
+    md_json_t *json = md_json_create(p);
+    if (json) {
+        switch (spec->type) {
+            case MD_PKEY_TYPE_DEFAULT:
+                md_json_sets("Default", json, MD_KEY_TYPE, NULL);
+                break;
+            case MD_PKEY_TYPE_RSA:
+                md_json_sets("RSA", json, MD_KEY_TYPE, NULL);
+                if (spec->params.rsa.bits >= MD_PKEY_RSA_BITS_MIN) {
+                    md_json_setl((long)spec->params.rsa.bits, json, MD_KEY_BITS, NULL);
+                }
+                break;
+            case MD_PKEY_TYPE_EC:
+                md_json_sets("EC", json, MD_KEY_TYPE, NULL);
+                if (spec->params.ec.curve) {
+                    md_json_sets(spec->params.ec.curve, json, MD_KEY_CURVE, NULL);
+                }
+                break;
+            default:
+                md_json_sets("Unsupported", json, MD_KEY_TYPE, NULL);
+                break;
+        }
+    }
+    return json;    
+}
+
+static apr_status_t spec_to_json(void *value, md_json_t *json, apr_pool_t *p, void *baton)
+{
+    md_json_t *jspec;
+    
+    (void)baton;
+    jspec = md_pkey_spec_to_json((md_pkey_spec_t*)value, p);
+    return md_json_setj(jspec, json, NULL);
+}
+
+md_json_t *md_pkeys_spec_to_json(const md_pkeys_spec_t *pks, apr_pool_t *p)
+{
+    md_json_t *j;
+    
+    if (pks->specs->nelts == 1) {
+        return md_pkey_spec_to_json(md_pkeys_spec_get(pks, 0), p);
+    }
+    j = md_json_create(p);
+    md_json_seta(pks->specs, spec_to_json, (void*)pks, j, "specs", NULL);
+    return md_json_getj(j, "specs", NULL);
+}
+
+md_pkey_spec_t *md_pkey_spec_from_json(struct md_json_t *json, apr_pool_t *p)
+{
+    md_pkey_spec_t *spec = apr_pcalloc(p, sizeof(*spec));
+    const char *s;
+    long l;
+    
+    if (spec) {
+        s = md_json_gets(json, MD_KEY_TYPE, NULL);
+        if (!s || !apr_strnatcasecmp("Default", s)) {
+            spec->type = MD_PKEY_TYPE_DEFAULT;
+        }
+        else if (!apr_strnatcasecmp("RSA", s)) {
+            spec->type = MD_PKEY_TYPE_RSA;
+            l = md_json_getl(json, MD_KEY_BITS, NULL);
+            if (l >= MD_PKEY_RSA_BITS_MIN) {
+                spec->params.rsa.bits = (unsigned int)l;
+            }
+            else {
+                spec->params.rsa.bits = MD_PKEY_RSA_BITS_DEF;
+            }
+        }
+        else if (!apr_strnatcasecmp("EC", s)) {
+            spec->type = MD_PKEY_TYPE_EC;
+            s = md_json_gets(json, MD_KEY_CURVE, NULL);
+            if (s) {
+                spec->params.ec.curve = apr_pstrdup(p, s);
+            }
+            else {
+                spec->params.ec.curve = NULL;
+            }
+        }
+    }
+    return spec;
+}
+
+static apr_status_t spec_from_json(void **pvalue, md_json_t *json, apr_pool_t *p, void *baton)
+{
+    (void)baton;
+    *pvalue = md_pkey_spec_from_json(json, p);
+    return APR_SUCCESS;
+}
+
+md_pkeys_spec_t *md_pkeys_spec_from_json(struct md_json_t *json, apr_pool_t *p)
+{
+    md_pkeys_spec_t *pks;
+    md_pkey_spec_t *spec;
+    
+    pks = md_pkeys_spec_make(p);
+    if (md_json_is(MD_JSON_TYPE_ARRAY, json, NULL)) {
+        md_json_geta(pks->specs, spec_from_json, pks, json, NULL);
+    }
+    else {
+        spec = md_pkey_spec_from_json(json, p);
+        md_pkeys_spec_add(pks, spec);
+    }
+    return pks;
+}
+
+static int pkey_spec_eq(md_pkey_spec_t *s1, md_pkey_spec_t *s2)
+{
+    if (s1 == s2) {
+        return 1;
+    }
+    if (s1 && s2 && s1->type == s2->type) {
+        switch (s1->type) {
+            case MD_PKEY_TYPE_DEFAULT:
+                return 1;
+            case MD_PKEY_TYPE_RSA:
+                if (s1->params.rsa.bits == s2->params.rsa.bits) {
+                    return 1;
+                }
+                break;
+            case MD_PKEY_TYPE_EC:
+                if (s1->params.ec.curve == s2->params.ec.curve) {
+                    return 1;
+                }
+                else if (!s1->params.ec.curve || !s2->params.ec.curve) {
+                    return 0;
+                }
+                return !strcmp(s1->params.ec.curve, s2->params.ec.curve);
+        }
+    }
+    return 0;
+}
+
+int md_pkeys_spec_eq(md_pkeys_spec_t *pks1, md_pkeys_spec_t *pks2)
+{
+    int i;
+    
+    if (pks1 == pks2) {
+        return 1;
+    }
+    if (pks1 && pks2 && pks1->specs->nelts == pks2->specs->nelts) {
+        for(i = 0; i < pks1->specs->nelts; ++i) {
+            if (!pkey_spec_eq(APR_ARRAY_IDX(pks1->specs, i, md_pkey_spec_t *),
+                              APR_ARRAY_IDX(pks2->specs, i, md_pkey_spec_t *))) {
+                return 0;
+            }
+        }
+        return 1;
+    }
+    return 0;
+}
+
+static md_pkey_spec_t *pkey_spec_clone(apr_pool_t *p, md_pkey_spec_t *spec)
+{
+    md_pkey_spec_t *nspec;
+    
+    nspec = apr_pcalloc(p, sizeof(*nspec));
+    nspec->type = spec->type;
+    switch (spec->type) {
+        case MD_PKEY_TYPE_DEFAULT:
+            break;
+        case MD_PKEY_TYPE_RSA:
+            nspec->params.rsa.bits = spec->params.rsa.bits;
+            break;
+        case MD_PKEY_TYPE_EC:
+            nspec->params.ec.curve = apr_pstrdup(p, spec->params.ec.curve);
+            break;
+    }
+    return nspec;
+}
+
+const char *md_pkey_spec_name(const md_pkey_spec_t *spec)
+{
+    if (!spec) return "rsa";
+    switch (spec->type) {
+        case MD_PKEY_TYPE_DEFAULT:
+        case MD_PKEY_TYPE_RSA:
+            return "rsa";
+        case MD_PKEY_TYPE_EC:
+            return spec->params.ec.curve;
+    }
+    return "unknown";
+}
+
+int md_pkeys_spec_is_empty(const md_pkeys_spec_t *pks)
+{
+    return NULL == pks || 0 == pks->specs->nelts;
+}
+
+md_pkeys_spec_t *md_pkeys_spec_clone(apr_pool_t *p, const md_pkeys_spec_t *pks)
+{
+    md_pkeys_spec_t *npks = NULL;
+    md_pkey_spec_t *spec;
+    int i;
+    
+    if (pks && pks->specs->nelts > 0) {
+        npks = apr_pcalloc(p, sizeof(*npks));
+        npks->specs = apr_array_make(p, pks->specs->nelts, sizeof(md_pkey_spec_t*));
+        for (i = 0; i < pks->specs->nelts; ++i) {
+            spec = APR_ARRAY_IDX(pks->specs, i, md_pkey_spec_t*);
+            APR_ARRAY_PUSH(npks->specs, md_pkey_spec_t*) = pkey_spec_clone(p, spec);
+        }
+    }
+    return npks;
+}
+
+int md_pkeys_spec_count(const md_pkeys_spec_t *pks)
+{
+    return md_pkeys_spec_is_empty(pks)? 1 : pks->specs->nelts;
+}
+
+static md_pkey_spec_t PkeySpecDef = { MD_PKEY_TYPE_DEFAULT, {{ 0 }} };
+
+md_pkey_spec_t *md_pkeys_spec_get(const md_pkeys_spec_t *pks, int index)
+{
+    if (md_pkeys_spec_is_empty(pks)) {
+        return index == 1? &PkeySpecDef : NULL;
+    }
+    else if (pks && index >= 0 && index < pks->specs->nelts) {
+        return APR_ARRAY_IDX(pks->specs, index, md_pkey_spec_t*);
+    }
+    return NULL;
+}
+
+static md_pkey_t *make_pkey(apr_pool_t *p) 
+{
+    md_pkey_t *pkey = apr_pcalloc(p, sizeof(*pkey));
+    pkey->pool = p;
+    return pkey;
+}
+
+static apr_status_t pkey_cleanup(void *data)
+{
+    md_pkey_t *pkey = data;
+    if (pkey->pkey) {
+        EVP_PKEY_free(pkey->pkey);
+        pkey->pkey = NULL;
+    }
+    return APR_SUCCESS;
+}
+
+void md_pkey_free(md_pkey_t *pkey)
+{
+    pkey_cleanup(pkey);
+}
+
+void *md_pkey_get_EVP_PKEY(struct md_pkey_t *pkey)
+{
+    return pkey->pkey;
+}
+
+apr_status_t md_pkey_fload(md_pkey_t **ppkey, apr_pool_t *p, 
+                           const char *key, apr_size_t key_len,
+                           const char *fname)
+{
+    apr_status_t rv = APR_ENOENT;
+    md_pkey_t *pkey;
+    BIO *bf;
+    passwd_ctx ctx;
+    
+    pkey =  make_pkey(p);
+    if (NULL != (bf = BIO_new_file(fname, "r"))) {
+        ctx.pass_phrase = key;
+        ctx.pass_len = (int)key_len;
+        
+        ERR_clear_error();
+        pkey->pkey = PEM_read_bio_PrivateKey(bf, NULL, pem_passwd, &ctx);
+        BIO_free(bf);
+        
+        if (pkey->pkey != NULL) {
+            rv = APR_SUCCESS;
+            apr_pool_cleanup_register(p, pkey, pkey_cleanup, apr_pool_cleanup_null);
+        }
+        else {
+            unsigned long err = ERR_get_error();
+            rv = APR_EINVAL;
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, p, 
+                          "error loading pkey %s: %s (pass phrase was %snull)", fname,
+                          ERR_error_string(err, NULL), key? "not " : ""); 
+        }
+    }
+    *ppkey = (APR_SUCCESS == rv)? pkey : NULL;
+    return rv;
+}
+
+static apr_status_t pkey_to_buffer(md_data_t *buf, md_pkey_t *pkey, apr_pool_t *p,
+                                   const char *pass, apr_size_t pass_len)
+{
+    BIO *bio = BIO_new(BIO_s_mem());
+    const EVP_CIPHER *cipher = NULL;
+    pem_password_cb *cb = NULL;
+    void *cb_baton = NULL;
+    apr_status_t rv = APR_SUCCESS;
+    passwd_ctx ctx;
+    unsigned long err;
+    int i;
+    
+    if (!bio) {
+        return APR_ENOMEM;
+    }
+    if (pass_len > INT_MAX) {
+        rv = APR_EINVAL;
+        goto cleanup;
+    }
+    if (pass && pass_len > 0) {
+        ctx.pass_phrase = pass;
+        ctx.pass_len = (int)pass_len;
+        cb = pem_passwd;
+        cb_baton = &ctx;
+        cipher = EVP_aes_256_cbc();
+        if (!cipher) {
+            rv = APR_ENOTIMPL;
+            goto cleanup;
+        }
+    }
+    
+    ERR_clear_error();
+#if 1
+    if (!PEM_write_bio_PKCS8PrivateKey(bio, pkey->pkey, cipher, NULL, 0, cb, cb_baton)) {
+#else 
+    if (!PEM_write_bio_PrivateKey(bio, pkey->pkey, cipher, NULL, 0, cb, cb_baton)) {
+#endif
+        err = ERR_get_error();
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "PEM_write key: %ld %s", 
+                      err, ERR_error_string(err, NULL)); 
+        rv = APR_EINVAL;
+        goto cleanup;
+    }
+
+    md_data_null(buf);
+    i = BIO_pending(bio);
+    if (i > 0) {
+        buf->data = apr_palloc(p, (apr_size_t)i);
+        i = BIO_read(bio, (char*)buf->data, i);
+        buf->len = (apr_size_t)i;
+    }
+
+cleanup:
+    BIO_free(bio);
+    return rv;
+}
+
+apr_status_t md_pkey_fsave(md_pkey_t *pkey, apr_pool_t *p, 
+                           const char *pass_phrase, apr_size_t pass_len,
+                           const char *fname, apr_fileperms_t perms)
+{
+    md_data_t buffer;
+    apr_status_t rv;
+    
+    if (APR_SUCCESS == (rv = pkey_to_buffer(&buffer, pkey, p, pass_phrase, pass_len))) {
+        return md_util_freplace(fname, perms, p, fwrite_buffer, &buffer); 
+    }
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "save pkey %s (%s pass phrase, len=%d)",
+                  fname, pass_len > 0? "with" : "without", (int)pass_len); 
+    return rv;
+}
+
+apr_status_t md_pkey_read_http(md_pkey_t **ppkey, apr_pool_t *pool,
+                               const struct md_http_response_t *res)
+{
+    apr_status_t rv;
+    apr_off_t data_len;
+    char *pem_data;
+    apr_size_t pem_len;
+    md_pkey_t *pkey;
+    BIO *bf;
+    passwd_ctx ctx;
+
+    rv = apr_brigade_length(res->body, 1, &data_len);
+    if (APR_SUCCESS != rv) goto leave;
+    if (data_len > 1024*1024) { /* certs usually are <2k each */
+        rv = APR_EINVAL;
+        goto leave;
+    }
+    rv = apr_brigade_pflatten(res->body, &pem_data, &pem_len, res->req->pool);
+    if (APR_SUCCESS != rv) goto leave;
+
+    if (NULL == (bf = BIO_new_mem_buf(pem_data, (int)pem_len))) {
+        rv = APR_ENOMEM;
+        goto leave;
+    }
+    pkey = make_pkey(pool);
+    ctx.pass_phrase = NULL;
+    ctx.pass_len = 0;
+    ERR_clear_error();
+    pkey->pkey = PEM_read_bio_PrivateKey(bf, NULL, NULL, &ctx);
+    BIO_free(bf);
+
+    if (pkey->pkey == NULL) {
+        unsigned long err = ERR_get_error();
+        rv = APR_EINVAL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, pool,
+                      "error loading pkey from http response: %s",
+                      ERR_error_string(err, NULL));
+        goto leave;
+    }
+    rv = APR_SUCCESS;
+    apr_pool_cleanup_register(pool, pkey, pkey_cleanup, apr_pool_cleanup_null);
+
+leave:
+    *ppkey = (APR_SUCCESS == rv)? pkey : NULL;
+    return rv;
+}
+
+/* Determine the message digest used for signing with the given private key. 
+ */
+static const EVP_MD *pkey_get_MD(md_pkey_t *pkey)
+{
+    switch (EVP_PKEY_id(pkey->pkey)) {
+#ifdef NID_ED25519
+    case NID_ED25519:
+        return NULL;
+#endif
+#ifdef NID_ED448
+    case NID_ED448:
+        return NULL;
+#endif
+    default:
+        return EVP_sha256();
+    }
+}
+
+static apr_status_t gen_rsa(md_pkey_t **ppkey, apr_pool_t *p, unsigned int bits)
+{
+    EVP_PKEY_CTX *ctx = NULL;
+    apr_status_t rv;
+    
+    *ppkey = make_pkey(p);
+    ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA, NULL);
+    if (ctx 
+        && EVP_PKEY_keygen_init(ctx) >= 0
+        && EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, (int)bits) >= 0
+        && EVP_PKEY_keygen(ctx, &(*ppkey)->pkey) >= 0) {
+        rv = APR_SUCCESS;
+    }
+    else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, 0, p, "error generate pkey RSA %d", bits); 
+        *ppkey = NULL;
+        rv = APR_EGENERAL;
+    }
+    
+    if (ctx != NULL) {
+        EVP_PKEY_CTX_free(ctx);
+    }
+    return rv;
+}
+
+static apr_status_t check_EC_curve(int nid, apr_pool_t *p) {
+    EC_builtin_curve *curves = NULL;
+    size_t nc, i;
+    int rv = APR_ENOENT;
+    
+    nc = EC_get_builtin_curves(NULL, 0);
+    if (NULL == (curves = OPENSSL_malloc(sizeof(*curves) * nc)) ||
+        nc != EC_get_builtin_curves(curves, nc)) {
+        rv = APR_EGENERAL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, 
+                      "error looking up OpenSSL builtin EC curves"); 
+        goto leave;
+    }
+    for (i = 0; i < nc; ++i) {
+        if (nid == curves[i].nid) {
+            rv = APR_SUCCESS;
+            break;
+        }
+    }
+leave:
+    OPENSSL_free(curves);
+    return rv;
+}
+
+static apr_status_t gen_ec(md_pkey_t **ppkey, apr_pool_t *p, const char *curve)
+{
+    EVP_PKEY_CTX *ctx = NULL;
+    apr_status_t rv;
+    int curve_nid = NID_undef;
+
+    /* 1. Convert the cure into its registered identifier. Curves can be known under
+     *    different names.
+     * 2. Determine, if the curve is supported by OpenSSL (or whatever is linked).
+     * 3. Generate the key, respecting the specific quirks some curves require.
+     */
+    curve_nid = EC_curve_nist2nid(curve);
+    /* In case this fails, try some names from other standards, like SECG */
+#ifdef NID_secp384r1
+    if (NID_undef == curve_nid && !apr_strnatcasecmp("secp384r1", curve)) {
+        curve_nid = NID_secp384r1;
+        curve = EC_curve_nid2nist(curve_nid);
+    }
+#endif
+#ifdef NID_X9_62_prime256v1
+    if (NID_undef == curve_nid && !apr_strnatcasecmp("secp256r1", curve)) {
+        curve_nid = NID_X9_62_prime256v1;
+        curve = EC_curve_nid2nist(curve_nid);
+    }
+#endif
+#ifdef NID_X9_62_prime192v1
+    if (NID_undef == curve_nid && !apr_strnatcasecmp("secp192r1", curve)) {
+        curve_nid = NID_X9_62_prime192v1;
+        curve = EC_curve_nid2nist(curve_nid);
+    }
+#endif
+#if defined(NID_X25519) && (!defined(LIBRESSL_VERSION_NUMBER) || \
+                            LIBRESSL_VERSION_NUMBER >= 0x3070000fL)
+    if (NID_undef == curve_nid && !apr_strnatcasecmp("X25519", curve)) {
+        curve_nid = NID_X25519;
+        curve = EC_curve_nid2nist(curve_nid);
+    }
+#endif
+    if (NID_undef == curve_nid) {
+        /* OpenSSL object/curve names */
+        curve_nid = OBJ_sn2nid(curve);
+    }
+    if (NID_undef == curve_nid) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "ec curve unknown: %s", curve); 
+        rv = APR_ENOTIMPL; goto leave;
+    }
+
+    *ppkey = make_pkey(p);
+    switch (curve_nid) {
+
+#if defined(NID_X25519) && (!defined(LIBRESSL_VERSION_NUMBER) || \
+                            LIBRESSL_VERSION_NUMBER >= 0x3070000fL)
+    case NID_X25519:
+        /* no parameters */
+        if (NULL == (ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X25519, NULL))
+            || EVP_PKEY_keygen_init(ctx) <= 0
+            || EVP_PKEY_keygen(ctx, &(*ppkey)->pkey) <= 0) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, 0, p, 
+                          "error generate EC key for group: %s", curve); 
+            rv = APR_EGENERAL; goto leave;
+        }
+        rv = APR_SUCCESS;
+        break;
+#endif
+
+#if defined(NID_X448) && !defined(LIBRESSL_VERSION_NUMBER)
+    case NID_X448:
+        /* no parameters */
+        if (NULL == (ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_X448, NULL))
+            || EVP_PKEY_keygen_init(ctx) <= 0
+            || EVP_PKEY_keygen(ctx, &(*ppkey)->pkey) <= 0) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, 0, p, 
+                          "error generate EC key for group: %s", curve); 
+            rv = APR_EGENERAL; goto leave;
+        }
+        rv = APR_SUCCESS;
+        break;
+#endif
+
+    default:
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+        if (APR_SUCCESS != (rv = check_EC_curve(curve_nid, p))) goto leave;
+        if (NULL == (ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL))
+            || EVP_PKEY_paramgen_init(ctx) <= 0 
+            || EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, curve_nid) <= 0
+            || EVP_PKEY_CTX_set_ec_param_enc(ctx, OPENSSL_EC_NAMED_CURVE) <= 0 
+            || EVP_PKEY_keygen_init(ctx) <= 0
+            || EVP_PKEY_keygen(ctx, &(*ppkey)->pkey) <= 0) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, 0, p, 
+                          "error generate EC key for group: %s", curve); 
+            rv = APR_EGENERAL; goto leave;
+        }
+#else
+        if (APR_SUCCESS != (rv = check_EC_curve(curve_nid, p))) goto leave;
+        if (NULL == (ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL))
+            || EVP_PKEY_keygen_init(ctx) <= 0
+            || EVP_PKEY_CTX_ctrl_str(ctx, "ec_paramgen_curve", curve) <= 0
+            || EVP_PKEY_keygen(ctx, &(*ppkey)->pkey) <= 0) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, 0, p,
+                          "error generate EC key for group: %s", curve);
+            rv = APR_EGENERAL; goto leave;
+        }
+#endif
+        rv = APR_SUCCESS;
+        break;
+    }
+    
+leave:
+    if (APR_SUCCESS != rv) *ppkey = NULL;
+    EVP_PKEY_CTX_free(ctx);
+    return rv;
+}
+
+apr_status_t md_pkey_gen(md_pkey_t **ppkey, apr_pool_t *p, md_pkey_spec_t *spec)
+{
+    md_pkey_type_t ptype = spec? spec->type : MD_PKEY_TYPE_DEFAULT;
+    switch (ptype) {
+        case MD_PKEY_TYPE_DEFAULT:
+            return gen_rsa(ppkey, p, MD_PKEY_RSA_BITS_DEF);
+        case MD_PKEY_TYPE_RSA:
+            return gen_rsa(ppkey, p, spec->params.rsa.bits);
+        case MD_PKEY_TYPE_EC:
+            return gen_ec(ppkey, p, spec->params.ec.curve);
+        default:
+            return APR_ENOTIMPL;
+    }
+}
+
+#if MD_USE_OPENSSL_PRE_1_1_API || (defined(LIBRESSL_VERSION_NUMBER) && \
+                                   LIBRESSL_VERSION_NUMBER < 0x2070000f)
+
+#ifndef NID_tlsfeature
+#define NID_tlsfeature          1020
+#endif
+
+static void RSA_get0_key(const RSA *r,
+                         const BIGNUM **n, const BIGNUM **e, const BIGNUM **d)
+{
+    if (n != NULL)
+        *n = r->n;
+    if (e != NULL)
+        *e = r->e;
+    if (d != NULL)
+        *d = r->d;
+}
+
+#endif
+
+static const char *bn64(const BIGNUM *b, apr_pool_t *p) 
+{
+    if (b) {
+        md_data_t buffer;
+
+        md_data_pinit(&buffer, (apr_size_t)BN_num_bytes(b), p);
+        if (buffer.data) {
+            BN_bn2bin(b, (unsigned char *)buffer.data);
+            return md_util_base64url_encode(&buffer, p);
+        }
+    }
+    return NULL;
+}
+
+const char *md_pkey_get_rsa_e64(md_pkey_t *pkey, apr_pool_t *p)
+{
+    const BIGNUM *e;
+    RSA *rsa = EVP_PKEY_get1_RSA(pkey->pkey);
+    
+    if (!rsa) {
+        return NULL;
+    }
+    RSA_get0_key(rsa, NULL, &e, NULL);
+    return bn64(e, p);
+}
+
+const char *md_pkey_get_rsa_n64(md_pkey_t *pkey, apr_pool_t *p)
+{
+    const BIGNUM *n;
+    RSA *rsa = EVP_PKEY_get1_RSA(pkey->pkey);
+    
+    if (!rsa) {
+        return NULL;
+    }
+    RSA_get0_key(rsa, &n, NULL, NULL);
+    return bn64(n, p);
+}
+
+apr_status_t md_crypt_sign64(const char **psign64, md_pkey_t *pkey, apr_pool_t *p, 
+                             const char *d, size_t dlen)
+{
+    EVP_MD_CTX *ctx = NULL;
+    md_data_t buffer;
+    unsigned int blen;
+    const char *sign64 = NULL;
+    apr_status_t rv = APR_ENOMEM;
+
+    md_data_pinit(&buffer, (apr_size_t)EVP_PKEY_size(pkey->pkey), p);
+    if (buffer.data) {
+        ctx = EVP_MD_CTX_create();
+        if (ctx) {
+            rv = APR_ENOTIMPL;
+            if (EVP_SignInit_ex(ctx, EVP_sha256(), NULL)) {
+                rv = APR_EGENERAL;
+                if (EVP_SignUpdate(ctx, d, dlen)) {
+                    if (EVP_SignFinal(ctx, (unsigned char*)buffer.data, &blen, pkey->pkey)) {
+                        buffer.len = blen;
+                        sign64 = md_util_base64url_encode(&buffer, p);
+                        if (sign64) {
+                            rv = APR_SUCCESS;
+                        }
+                    }
+                }
+            }
+        }
+        
+        if (ctx) {
+            EVP_MD_CTX_destroy(ctx);
+        }
+    }
+    
+    if (rv != APR_SUCCESS) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, p, "signing"); 
+    }
+    
+    *psign64 = sign64;
+    return rv;
+}
+
+static apr_status_t sha256_digest(md_data_t **pdigest, apr_pool_t *p, const md_data_t *buf)
+{
+    EVP_MD_CTX *ctx = NULL;
+    md_data_t *digest;
+    apr_status_t rv = APR_ENOMEM;
+    unsigned int dlen;
+
+    digest = md_data_pmake(EVP_MAX_MD_SIZE, p);
+    ctx = EVP_MD_CTX_create();
+    if (ctx) {
+        rv = APR_ENOTIMPL;
+        if (EVP_DigestInit_ex(ctx, EVP_sha256(), NULL)) {
+            rv = APR_EGENERAL;
+            if (EVP_DigestUpdate(ctx, (unsigned char*)buf->data, buf->len)) {
+                if (EVP_DigestFinal(ctx, (unsigned char*)digest->data, &dlen)) {
+                    digest->len = dlen;
+                    rv = APR_SUCCESS;
+                }
+            }
+        }
+    }
+    if (ctx) {
+        EVP_MD_CTX_destroy(ctx);
+    }
+    *pdigest = (APR_SUCCESS == rv)? digest : NULL;
+    return rv;
+}
+
+apr_status_t md_crypt_sha256_digest64(const char **pdigest64, apr_pool_t *p, const md_data_t *d)
+{
+    const char *digest64 = NULL;
+    md_data_t *digest;
+    apr_status_t rv;
+    
+    if (APR_SUCCESS == (rv = sha256_digest(&digest, p, d))) {
+        if (NULL == (digest64 = md_util_base64url_encode(digest, p))) {
+            rv = APR_EGENERAL;
+        }
+    }
+    *pdigest64 = digest64;
+    return rv;
+}
+
+apr_status_t md_crypt_sha256_digest_hex(const char **pdigesthex, apr_pool_t *p, 
+                                        const md_data_t *data)
+{
+    md_data_t *digest;
+    apr_status_t rv;
+    
+    if (APR_SUCCESS == (rv = sha256_digest(&digest, p, data))) {
+        return md_data_to_hex(pdigesthex, 0, p, digest);
+    }
+    *pdigesthex = NULL;
+    return rv;
+}
+
+apr_status_t md_crypt_hmac64(const char **pmac64, const md_data_t *hmac_key,
+                             apr_pool_t *p, const char *d, size_t dlen)
+{
+    const char *mac64 = NULL;
+    unsigned char *s;
+    unsigned int digest_len = 0;
+    md_data_t *digest;
+    apr_status_t rv = APR_SUCCESS;
+
+    digest = md_data_pmake(EVP_MAX_MD_SIZE, p);
+    s = HMAC(EVP_sha256(), (const unsigned char*)hmac_key->data, (int)hmac_key->len,
+             (const unsigned char*)d, (size_t)dlen,
+             (unsigned char*)digest->data, &digest_len);
+    if (!s) {
+        rv = APR_EINVAL;
+        goto cleanup;
+    }
+    digest->len = digest_len;
+    mac64 = md_util_base64url_encode(digest, p);
+
+cleanup:
+    *pmac64 = (APR_SUCCESS == rv)? mac64 : NULL;
+    return rv;
+}
+
+/**************************************************************************************************/
+/* certificates */
+
+struct md_cert_t {
+    apr_pool_t *pool;
+    X509 *x509;
+    apr_array_header_t *alt_names;
+};
+
+static apr_status_t cert_cleanup(void *data)
+{
+    md_cert_t *cert = data;
+    if (cert->x509) {
+        X509_free(cert->x509);
+        cert->x509 = NULL;
+    }
+    return APR_SUCCESS;
+}
+
+md_cert_t *md_cert_wrap(apr_pool_t *p, void *x509) 
+{
+    md_cert_t *cert = apr_pcalloc(p, sizeof(*cert));
+    cert->pool = p;
+    cert->x509 = x509;
+    return cert;
+}
+
+md_cert_t *md_cert_make(apr_pool_t *p, void *x509) 
+{
+    md_cert_t *cert = md_cert_wrap(p, x509);
+    apr_pool_cleanup_register(p, cert, cert_cleanup, apr_pool_cleanup_null);
+    return cert;
+}
+
+void *md_cert_get_X509(const md_cert_t *cert)
+{
+    return cert->x509;
+}
+
+const char *md_cert_get_serial_number(const md_cert_t *cert, apr_pool_t *p)
+{
+    const char *s = "";
+    BIGNUM *bn; 
+    const char *serial;
+    const ASN1_INTEGER *ai = X509_get_serialNumber(cert->x509);
+    if (ai) {
+        bn = ASN1_INTEGER_to_BN(ai, NULL);
+        serial = BN_bn2hex(bn);
+        s = apr_pstrdup(p, serial);
+        OPENSSL_free((void*)serial);
+        OPENSSL_free((void*)bn);
+    }
+    return s;
+}
+
+int md_certs_are_equal(const md_cert_t *a, const md_cert_t *b)
+{
+    return X509_cmp(a->x509, b->x509) == 0;
+}
+
+int md_cert_is_valid_now(const md_cert_t *cert)
+{
+    return ((X509_cmp_current_time(X509_get_notBefore(cert->x509)) < 0)
+            && (X509_cmp_current_time(X509_get_notAfter(cert->x509)) > 0));
+}
+
+int md_cert_has_expired(const md_cert_t *cert)
+{
+    return (X509_cmp_current_time(X509_get_notAfter(cert->x509)) <= 0);
+}
+
+apr_time_t md_cert_get_not_after(const md_cert_t *cert)
+{
+    return md_asn1_time_get(X509_get_notAfter(cert->x509));
+}
+
+apr_time_t md_cert_get_not_before(const md_cert_t *cert)
+{
+    return md_asn1_time_get(X509_get_notBefore(cert->x509));
+}
+
+md_timeperiod_t md_cert_get_valid(const md_cert_t *cert)
+{
+    md_timeperiod_t p;
+    p.start = md_cert_get_not_before(cert);
+    p.end = md_cert_get_not_after(cert);
+    return p;
+}
+
+int md_cert_covers_domain(md_cert_t *cert, const char *domain_name)
+{
+    apr_array_header_t *alt_names;
+
+    md_cert_get_alt_names(&alt_names, cert, cert->pool);
+    if (alt_names) {
+        return md_array_str_index(alt_names, domain_name, 0, 0) >= 0;
+    }
+    return 0;
+}
+
+int md_cert_covers_md(md_cert_t *cert, const md_t *md)
+{
+    const char *name;
+    int i;
+    
+    if (!cert->alt_names) {
+        md_cert_get_alt_names(&cert->alt_names, cert, cert->pool);
+    }
+    if (cert->alt_names) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, cert->pool, "cert has %d alt names",
+                      cert->alt_names->nelts); 
+        for (i = 0; i < md->domains->nelts; ++i) {
+            name = APR_ARRAY_IDX(md->domains, i, const char *);
+            if (!md_dns_domains_match(cert->alt_names, name)) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, cert->pool, 
+                              "md domain %s not covered by cert", name);
+                return 0;
+            }
+        }
+        return 1;
+    }
+    else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, 0, cert->pool, "cert has NO alt names");
+    }
+    return 0;
+}
+
+apr_status_t md_cert_get_issuers_uri(const char **puri, const md_cert_t *cert, apr_pool_t *p)
+{
+    apr_status_t rv = APR_ENOENT;
+    STACK_OF(ACCESS_DESCRIPTION) *xinfos;
+    const char *uri = NULL;
+    unsigned char *buf;
+    int i;
+
+    xinfos = X509_get_ext_d2i(cert->x509, NID_info_access, NULL, NULL);
+    if (xinfos) {
+        for (i = 0; i < sk_ACCESS_DESCRIPTION_num(xinfos); i++) {
+            ACCESS_DESCRIPTION *val = sk_ACCESS_DESCRIPTION_value(xinfos, i);
+            if (OBJ_obj2nid(val->method) == NID_ad_ca_issuers
+                    && val->location && val->location->type == GEN_URI) {
+                ASN1_STRING_to_UTF8(&buf, val->location->d.uniformResourceIdentifier);
+                uri = apr_pstrdup(p, (char *)buf);
+                OPENSSL_free(buf);
+                rv = APR_SUCCESS;
+                break;
+            }
+        }
+        sk_ACCESS_DESCRIPTION_pop_free(xinfos, ACCESS_DESCRIPTION_free);
+    } 
+    *puri = (APR_SUCCESS == rv)? uri : NULL;
+    return rv;
+}
+
+apr_status_t md_cert_get_alt_names(apr_array_header_t **pnames, const md_cert_t *cert, apr_pool_t *p)
+{
+    apr_array_header_t *names;
+    apr_status_t rv = APR_ENOENT;
+    STACK_OF(GENERAL_NAME) *xalt_names;
+    unsigned char *buf;
+    int i;
+
+    xalt_names = X509_get_ext_d2i(cert->x509, NID_subject_alt_name, NULL, NULL);
+    if (xalt_names) {
+        GENERAL_NAME *cval;
+        const unsigned char *ip;
+        int len;
+        
+        names = apr_array_make(p, sk_GENERAL_NAME_num(xalt_names), sizeof(char *));
+        for (i = 0; i < sk_GENERAL_NAME_num(xalt_names); ++i) {
+            cval = sk_GENERAL_NAME_value(xalt_names, i);
+            switch (cval->type) {
+                case GEN_DNS:
+                case GEN_URI:
+                    ASN1_STRING_to_UTF8(&buf, cval->d.ia5);
+                    APR_ARRAY_PUSH(names, const char *) = apr_pstrdup(p, (char*)buf);
+                    OPENSSL_free(buf);
+                    break;
+                case GEN_IPADD:
+                    len = ASN1_STRING_length(cval->d.iPAddress);
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+                    ip = ASN1_STRING_data(cval->d.iPAddress);
+#else
+                    ip = ASN1_STRING_get0_data(cval->d.iPAddress);
+#endif
+                    if (len ==  4)      /* IPv4 address */
+                        APR_ARRAY_PUSH(names, const char *) = apr_psprintf(p, "%u.%u.%u.%u",
+                                                                           ip[0], ip[1], ip[2], ip[3]);
+                    else if (len == 16) /* IPv6 address */
+                        APR_ARRAY_PUSH(names, const char *) = apr_psprintf(p, "%02x%02x%02x%02x:"
+                                                                              "%02x%02x%02x%02x:"
+                                                                              "%02x%02x%02x%02x:"
+                                                                              "%02x%02x%02x%02x",
+                                                                           ip[0],  ip[1],  ip[2],  ip[3],
+                                                                           ip[4],  ip[5],  ip[6],  ip[7],
+                                                                           ip[8],  ip[9],  ip[10], ip[11],
+                                                                           ip[12], ip[13], ip[14], ip[15]);
+                    else {
+                        ; /* Unknown address type - Log?  Assert? */
+                    }
+                    break;
+                default:
+                    break;
+            }
+        }
+        sk_GENERAL_NAME_pop_free(xalt_names, GENERAL_NAME_free);
+        rv = APR_SUCCESS;
+    }
+    *pnames = (APR_SUCCESS == rv)? names : NULL;
+    return rv;
+}
+
+apr_status_t md_cert_fload(md_cert_t **pcert, apr_pool_t *p, const char *fname)
+{
+    FILE *f;
+    apr_status_t rv;
+    md_cert_t *cert;
+    X509 *x509;
+    
+    rv = md_util_fopen(&f, fname, "r");
+    if (rv == APR_SUCCESS) {
+    
+        x509 = PEM_read_X509(f, NULL, NULL, NULL);
+        rv = fclose(f);
+        if (x509 != NULL) {
+            cert =  md_cert_make(p, x509);
+        }
+        else {
+            rv = APR_EINVAL;
+        }
+    }
+
+    *pcert = (APR_SUCCESS == rv)? cert : NULL;
+    return rv;
+}
+
+static apr_status_t cert_to_buffer(md_data_t *buffer, const md_cert_t *cert, apr_pool_t *p)
+{
+    BIO *bio = BIO_new(BIO_s_mem());
+    int i;
+    
+    if (!bio) {
+        return APR_ENOMEM;
+    }
+
+    ERR_clear_error();
+    PEM_write_bio_X509(bio, cert->x509);
+    if (ERR_get_error() > 0) {
+        BIO_free(bio);
+        return APR_EINVAL;
+    }
+
+    i = BIO_pending(bio);
+    if (i > 0) {
+        buffer->data = apr_palloc(p, (apr_size_t)i);
+        i = BIO_read(bio, (char*)buffer->data, i);
+        buffer->len = (apr_size_t)i;
+    }
+    BIO_free(bio);
+    return APR_SUCCESS;
+}
+
+apr_status_t md_cert_fsave(md_cert_t *cert, apr_pool_t *p, 
+                           const char *fname, apr_fileperms_t perms)
+{
+    md_data_t buffer;
+    apr_status_t rv;
+
+    md_data_null(&buffer);
+    if (APR_SUCCESS == (rv = cert_to_buffer(&buffer, cert, p))) {
+        return md_util_freplace(fname, perms, p, fwrite_buffer, &buffer); 
+    }
+    return rv;
+}
+
+apr_status_t md_cert_to_base64url(const char **ps64, const md_cert_t *cert, apr_pool_t *p)
+{
+    md_data_t buffer;
+    apr_status_t rv;
+
+    md_data_null(&buffer);
+    if (APR_SUCCESS == (rv = cert_to_buffer(&buffer, cert, p))) {
+        *ps64 = md_util_base64url_encode(&buffer, p);
+        return APR_SUCCESS;
+    }
+    *ps64 = NULL;
+    return rv;
+}
+
+apr_status_t md_cert_to_sha256_digest(md_data_t **pdigest, const md_cert_t *cert, apr_pool_t *p)
+{
+    md_data_t *digest;
+    unsigned int dlen;
+
+    digest = md_data_pmake(EVP_MAX_MD_SIZE, p);
+    X509_digest(cert->x509, EVP_sha256(), (unsigned char*)digest->data, &dlen);
+    digest->len = dlen;
+
+    *pdigest = digest;
+    return APR_SUCCESS;
+}
+
+apr_status_t md_cert_to_sha256_fingerprint(const char **pfinger, const md_cert_t *cert, apr_pool_t *p)
+{
+    md_data_t *digest;
+    apr_status_t rv;
+
+    rv = md_cert_to_sha256_digest(&digest, cert, p);
+    if (APR_SUCCESS == rv) {
+        return md_data_to_hex(pfinger, 0, p, digest);
+    }
+    *pfinger = NULL;
+    return rv;
+}
+
+static int md_cert_read_pem(BIO *bf, apr_pool_t *p, md_cert_t **pcert)
+{
+    md_cert_t *cert;
+    X509 *x509;
+    apr_status_t rv = APR_ENOENT;
+    
+    ERR_clear_error();
+    x509 = PEM_read_bio_X509(bf, NULL, NULL, NULL);
+    if (x509 == NULL) goto cleanup;
+    cert = md_cert_make(p, x509);
+    rv = APR_SUCCESS;
+cleanup:
+    *pcert = (APR_SUCCESS == rv)? cert : NULL;
+    return rv;
+}
+
+apr_status_t md_cert_read_chain(apr_array_header_t *chain, apr_pool_t *p,
+                                const char *pem, apr_size_t pem_len)
+{
+    BIO *bf = NULL;
+    apr_status_t rv = APR_SUCCESS;
+    md_cert_t *cert;
+    int added = 0;
+
+    if (NULL == (bf = BIO_new_mem_buf(pem, (int)pem_len))) {
+        rv = APR_ENOMEM;
+        goto cleanup;
+    }
+    while (APR_SUCCESS == (rv = md_cert_read_pem(bf, chain->pool, &cert))) {
+        APR_ARRAY_PUSH(chain, md_cert_t *) = cert;
+        added = 1;
+    }
+    if (APR_ENOENT == rv && added) {
+        rv = APR_SUCCESS;
+    }
+
+cleanup:
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, rv, p, "read chain with %d certs", chain->nelts);
+    if (bf) BIO_free(bf);
+    return rv;
+}
+
+apr_status_t md_cert_read_http(md_cert_t **pcert, apr_pool_t *p, 
+                               const md_http_response_t *res)
+{
+    const char *ct;
+    apr_off_t data_len;
+    char *der;
+    apr_size_t der_len;
+    md_cert_t *cert = NULL;
+    apr_status_t rv;
+    
+    ct = apr_table_get(res->headers, "Content-Type");
+    ct = md_util_parse_ct(res->req->pool, ct);
+    if (!res->body || !ct || strcmp("application/pkix-cert", ct)) {
+        rv = APR_ENOENT;
+        goto out;
+    }
+    
+    if (APR_SUCCESS == (rv = apr_brigade_length(res->body, 1, &data_len))) {
+        if (data_len > 1024*1024) { /* certs usually are <2k each */
+            return APR_EINVAL;
+        }
+        if (APR_SUCCESS == (rv = apr_brigade_pflatten(res->body, &der, &der_len, res->req->pool))) {
+            const unsigned char *bf = (const unsigned char*)der;
+            X509 *x509;
+            
+            if (NULL == (x509 = d2i_X509(NULL, &bf, (long)der_len))) {
+                rv = APR_EINVAL;
+                goto out;
+            }
+            else {
+                cert = md_cert_make(p, x509);
+                rv = APR_SUCCESS;
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, rv, p,
+                    "parsing cert from content-type=%s, content-length=%ld", ct, (long)data_len);
+            }
+        }
+    }
+out:
+    *pcert = (APR_SUCCESS == rv)? cert : NULL;
+    return rv;
+}
+
+apr_status_t md_cert_chain_read_http(struct apr_array_header_t *chain,
+                                     apr_pool_t *p, const struct md_http_response_t *res)
+{
+    const char *ct = NULL;
+    apr_off_t blen;
+    apr_size_t data_len = 0;
+    char *data;
+    md_cert_t *cert;
+    apr_status_t rv = APR_ENOENT;
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, p,
+        "chain_read, processing %d response", res->status);
+    if (APR_SUCCESS != (rv = apr_brigade_length(res->body, 1, &blen))) goto cleanup;
+    if (blen > 1024*1024) { /* certs usually are <2k each */
+        rv = APR_EINVAL;
+        goto cleanup;
+    }
+    
+    data_len = (apr_size_t)blen;
+    ct = apr_table_get(res->headers, "Content-Type");
+    if (!res->body || !ct) goto cleanup;
+    ct = md_util_parse_ct(res->req->pool, ct);
+    if (!strcmp("application/pkix-cert", ct)) {
+        rv = md_cert_read_http(&cert, p, res);
+        if (APR_SUCCESS != rv) goto cleanup;
+        APR_ARRAY_PUSH(chain, md_cert_t *) = cert;
+    }
+    else if (!strcmp("application/pem-certificate-chain", ct)
+        || !strncmp("text/plain", ct, sizeof("text/plain")-1)) {
+        /* Some servers seem to think 'text/plain' is sufficient, see #232 */
+        rv = apr_brigade_pflatten(res->body, &data, &data_len, res->req->pool);
+        if (APR_SUCCESS != rv) goto cleanup;
+        rv = md_cert_read_chain(chain, res->req->pool, data, data_len);
+    }
+    else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p,
+            "attempting to parse certificates from unrecognized content-type: %s", ct);
+        rv = apr_brigade_pflatten(res->body, &data, &data_len, res->req->pool);
+        if (APR_SUCCESS != rv) goto cleanup;
+        rv = md_cert_read_chain(chain, res->req->pool, data, data_len);
+        if (APR_SUCCESS == rv && chain->nelts == 0) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p,
+                "certificate chain response did not contain any certificates "
+                "(suspicious content-type: %s)", ct);
+            rv = APR_ENOENT;
+        }
+    }
+cleanup:
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, rv, p,
+        "parsed certs from content-type=%s, content-length=%ld", ct, (long)data_len);
+    return rv;
+}
+
+md_cert_state_t md_cert_state_get(const md_cert_t *cert)
+{
+    if (cert->x509) {
+        return md_cert_is_valid_now(cert)? MD_CERT_VALID : MD_CERT_EXPIRED;
+    }
+    return MD_CERT_UNKNOWN;
+}
+
+apr_status_t md_chain_fappend(struct apr_array_header_t *certs, apr_pool_t *p, const char *fname)
+{
+    FILE *f;
+    apr_status_t rv;
+    X509 *x509;
+    md_cert_t *cert;
+    unsigned long err;
+    
+    rv = md_util_fopen(&f, fname, "r");
+    if (rv == APR_SUCCESS) {
+        ERR_clear_error();
+        while (NULL != (x509 = PEM_read_X509(f, NULL, NULL, NULL))) {
+            cert = md_cert_make(p, x509);
+            APR_ARRAY_PUSH(certs, md_cert_t *) = cert;
+        }
+        fclose(f);
+        
+        if (0 < (err =  ERR_get_error())
+            && !(ERR_GET_LIB(err) == ERR_LIB_PEM && ERR_GET_REASON(err) == PEM_R_NO_START_LINE)) {
+            /* not the expected one when no more PEM encodings are found */
+            rv = APR_EINVAL;
+            goto out;
+        }
+        
+        if (certs->nelts == 0) {
+            /* Did not find any. This is acceptable unless the file has a certain size
+             * when we no longer accept it as empty chain file. Something seems to be
+             * wrong then. */
+            apr_finfo_t info;
+            if (APR_SUCCESS == apr_stat(&info, fname, APR_FINFO_SIZE, p) && info.size >= 1024) {
+                /* "Too big for a moon." */
+                rv = APR_EINVAL;
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, 
+                              "no certificates in non-empty chain %s", fname);
+                goto out;
+            }
+        }        
+    }
+out:
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, p, "read chain file %s, found %d certs", 
+                  fname, certs? certs->nelts : 0);
+    return rv;
+}
+
+apr_status_t md_chain_fload(apr_array_header_t **pcerts, apr_pool_t *p, const char *fname)
+{
+    apr_array_header_t *certs;
+    apr_status_t rv;
+
+    certs = apr_array_make(p, 5, sizeof(md_cert_t *));
+    rv = md_chain_fappend(certs, p, fname);
+    *pcerts = (APR_SUCCESS == rv)? certs : NULL;
+    return rv;
+}
+
+apr_status_t md_chain_fsave(apr_array_header_t *certs, apr_pool_t *p, 
+                            const char *fname, apr_fileperms_t perms)
+{
+    FILE *f;
+    apr_status_t rv;
+    const md_cert_t *cert;
+    unsigned long err = 0;
+    int i;
+    
+    (void)p;
+    rv = md_util_fopen(&f, fname, "w");
+    if (rv == APR_SUCCESS) {
+        apr_file_perms_set(fname, perms);
+        ERR_clear_error();
+        for (i = 0; i < certs->nelts; ++i) {
+            cert = APR_ARRAY_IDX(certs, i, const md_cert_t *);
+            assert(cert->x509);
+            
+            PEM_write_X509(f, cert->x509);
+            
+            if (0 < (err = ERR_get_error())) {
+                break;
+            }
+            
+        }
+        rv = fclose(f);
+        if (err) {
+            rv = APR_EINVAL;
+        }
+    }
+    return rv;
+}
+
+/**************************************************************************************************/
+/* certificate signing requests */
+
+static const char *alt_names(apr_array_header_t *domains, apr_pool_t *p)
+{
+    const char *alts = "", *sep = "", *domain;
+    int i;
+    
+    for (i = 0; i < domains->nelts; ++i) {
+        domain = APR_ARRAY_IDX(domains, i, const char *);
+        alts = apr_psprintf(p, "%s%sDNS:%s", alts, sep, domain);
+        sep = ",";
+    }
+    return alts;
+}
+
+static apr_status_t add_ext(X509 *x, int nid, const char *value, apr_pool_t *p)
+{
+    X509_EXTENSION *ext = NULL;
+    X509V3_CTX ctx;
+    apr_status_t rv;
+
+    ERR_clear_error();
+    X509V3_set_ctx_nodb(&ctx);
+    X509V3_set_ctx(&ctx, x, x, NULL, NULL, 0);
+    if (NULL == (ext = X509V3_EXT_conf_nid(NULL, &ctx, nid, (char*)value))) {
+        unsigned long err =  ERR_get_error();
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "add_ext, create, nid=%d value='%s' "
+                      "(lib=%d, reason=%d)", nid, value, ERR_GET_LIB(err), ERR_GET_REASON(err)); 
+        return APR_EGENERAL;
+    }
+    
+    ERR_clear_error();
+    rv = X509_add_ext(x, ext, -1)? APR_SUCCESS : APR_EINVAL;
+    if (APR_SUCCESS != rv) {
+        unsigned long err =  ERR_get_error();
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "add_ext, add, nid=%d value='%s' "
+                      "(lib=%d, reason=%d)", nid, value, ERR_GET_LIB(err), ERR_GET_REASON(err)); 
+    }
+    X509_EXTENSION_free(ext);
+    return rv;
+}
+
+static apr_status_t sk_add_alt_names(STACK_OF(X509_EXTENSION) *exts,
+                                     apr_array_header_t *domains, apr_pool_t *p)
+{
+    if (domains->nelts > 0) {
+        X509_EXTENSION *x;
+        
+        x = X509V3_EXT_conf_nid(NULL, NULL, NID_subject_alt_name, (char*)alt_names(domains, p));
+        if (NULL == x) {
+            return APR_EGENERAL;
+        }
+        sk_X509_EXTENSION_push(exts, x);
+    }
+    return APR_SUCCESS;
+}
+
+#define MD_OID_MUST_STAPLE_NUM          "1.3.6.1.5.5.7.1.24"
+#define MD_OID_MUST_STAPLE_SNAME        "tlsfeature"
+#define MD_OID_MUST_STAPLE_LNAME        "TLS Feature" 
+
+int md_cert_must_staple(const md_cert_t *cert)
+{
+    /* In case we do not get the NID for it, we treat this as not set. */
+    int nid = MD_GET_NID(MUST_STAPLE);
+    return ((NID_undef != nid)) && X509_get_ext_by_NID(cert->x509, nid, -1) >= 0;
+}
+
+static apr_status_t add_must_staple(STACK_OF(X509_EXTENSION) *exts, const char *name, apr_pool_t *p)
+{
+    X509_EXTENSION *x;
+    int nid;
+    
+    nid = MD_GET_NID(MUST_STAPLE);
+    if (NID_undef == nid) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, 
+                      "%s: unable to get NID for v3 must-staple TLS feature", name);
+        return APR_ENOTIMPL;
+    }
+    x = X509V3_EXT_conf_nid(NULL, NULL, nid, (char*)"DER:30:03:02:01:05");
+    if (NULL == x) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, 
+                      "%s: unable to create x509 extension for must-staple", name);
+        return APR_EGENERAL;
+    }
+    sk_X509_EXTENSION_push(exts, x);
+    return APR_SUCCESS;
+}
+
+apr_status_t md_cert_req_create(const char **pcsr_der_64, const char *name,
+                                apr_array_header_t *domains, int must_staple, 
+                                md_pkey_t *pkey, apr_pool_t *p)
+{
+    const char *s, *csr_der_64 = NULL;
+    const unsigned char *domain;
+    X509_REQ *csr;
+    X509_NAME *n = NULL;
+    STACK_OF(X509_EXTENSION) *exts = NULL;
+    apr_status_t rv;
+    md_data_t csr_der;
+    int csr_der_len;
+    
+    assert(domains->nelts > 0);
+    md_data_null(&csr_der);
+
+    if (NULL == (csr = X509_REQ_new()) 
+        || NULL == (exts = sk_X509_EXTENSION_new_null())
+        || NULL == (n = X509_NAME_new())) {
+        rv = APR_ENOMEM;
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: openssl alloc X509 things", name);
+        goto out; 
+    }
+
+    /* subject name == first domain */
+    domain = APR_ARRAY_IDX(domains, 0, const unsigned char *);
+    /* Do not set the domain in the CN if it is longer than 64 octets.
+     * Instead, let the CA choose a 'proper' name. At the moment (2021-01), LE will
+     * inspect all SAN names and use one < 64 chars if it can be found. It will fail
+     * otherwise.
+     * The reason we do not check this beforehand is that the restrictions on CNs
+     * are in flux. They used to be authoritative, now browsers no longer do that, but
+     * no one wants to hand out a cert with "google.com" as CN either. So, we leave
+     * it for the CA to decide if and how it hands out a cert for this or fails.
+     * This solves issue where the name is too long, see #227 */
+    if (strlen((const char*)domain) < 64
+        && (!X509_NAME_add_entry_by_txt(n, "CN", MBSTRING_ASC, domain, -1, -1, 0)
+            || !X509_REQ_set_subject_name(csr, n))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "%s: REQ name add entry", name);
+        rv = APR_EGENERAL; goto out;
+    }
+    /* collect extensions, such as alt names and must staple */
+    if (APR_SUCCESS != (rv = sk_add_alt_names(exts, domains, p))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: collecting alt names", name);
+        rv = APR_EGENERAL; goto out;
+    }
+    if (must_staple && APR_SUCCESS != (rv = add_must_staple(exts, name, p))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: you requested that a certificate "
+            "is created with the 'must-staple' extension, however the SSL library was "
+            "unable to initialized that extension. Please file a bug report on which platform "
+            "and with which library this happens. To continue before this problem is resolved, "
+            "configure 'MDMustStaple off' for your domains", name);
+        rv = APR_EGENERAL; goto out;
+    }
+    /* add extensions to csr */
+    if (sk_X509_EXTENSION_num(exts) > 0 && !X509_REQ_add_extensions(csr, exts)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: adding exts", name);
+        rv = APR_EGENERAL; goto out;
+    }
+    /* add our key */
+    if (!X509_REQ_set_pubkey(csr, pkey->pkey)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: set pkey in csr", name);
+        rv = APR_EGENERAL; goto out;
+    }
+    /* sign, der encode and base64url encode */
+    if (!X509_REQ_sign(csr, pkey->pkey, pkey_get_MD(pkey))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: sign csr", name);
+        rv = APR_EGENERAL; goto out;
+    }
+    if ((csr_der_len = i2d_X509_REQ(csr, NULL)) < 0) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: der length", name);
+        rv = APR_EGENERAL; goto out;
+    }
+    csr_der.len = (apr_size_t)csr_der_len;
+    s = csr_der.data = apr_pcalloc(p, csr_der.len + 1);
+    if (i2d_X509_REQ(csr, (unsigned char**)&s) != csr_der_len) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: csr der enc", name);
+        rv = APR_EGENERAL; goto out;
+    }
+    csr_der_64 = md_util_base64url_encode(&csr_der, p);
+    rv = APR_SUCCESS;
+    
+out:
+    if (exts) {
+        sk_X509_EXTENSION_pop_free(exts, X509_EXTENSION_free);
+    }
+    if (csr) {
+        X509_REQ_free(csr);
+    }
+    if (n) {
+        X509_NAME_free(n);
+    }
+    *pcsr_der_64 = (APR_SUCCESS == rv)? csr_der_64 : NULL;
+    return rv;
+}
+
+static apr_status_t mk_x509(X509 **px, md_pkey_t *pkey, const char *cn,
+                            apr_interval_time_t valid_for, apr_pool_t *p)
+{
+    X509 *x = NULL;
+    X509_NAME *n = NULL;
+    BIGNUM *big_rnd = NULL;
+    ASN1_INTEGER *asn1_rnd = NULL;
+    unsigned char rnd[20];
+    int days;
+    apr_status_t rv;
+    
+    if (NULL == (x = X509_new()) 
+        || NULL == (n = X509_NAME_new())) {
+        rv = APR_ENOMEM;
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "%s: openssl alloc X509 things", cn);
+        goto out; 
+    }
+
+    if (APR_SUCCESS != (rv = md_rand_bytes(rnd, sizeof(rnd), p))
+        || !(big_rnd = BN_bin2bn(rnd, sizeof(rnd), NULL))
+        || !(asn1_rnd = BN_to_ASN1_INTEGER(big_rnd, NULL))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "%s: setup random serial", cn);
+        rv = APR_EGENERAL; goto out;
+    }
+    if (!X509_set_serialNumber(x, asn1_rnd)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "%s: set serial number", cn);
+        rv = APR_EGENERAL; goto out;
+    }
+    if (1 != X509_set_version(x, 2L)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "%s: setting x.509v3", cn);
+        rv = APR_EGENERAL; goto out;
+    }
+    /* set common name and issuer */
+    if (!X509_NAME_add_entry_by_txt(n, "CN", MBSTRING_ASC, (const unsigned char*)cn, -1, -1, 0)
+        || !X509_set_subject_name(x, n)
+        || !X509_set_issuer_name(x, n)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "%s: name add entry", cn);
+        rv = APR_EGENERAL; goto out;
+    }
+    /* cert are unconstrained (but not very trustworthy) */
+    if (APR_SUCCESS != (rv = add_ext(x, NID_basic_constraints, "critical,CA:FALSE", p))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: set basic constraints ext", cn);
+        goto out;
+    }
+    /* add our key */
+    if (!X509_set_pubkey(x, pkey->pkey)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: set pkey in x509", cn);
+        rv = APR_EGENERAL; goto out;
+    }
+    /* validity */
+    days = (int)((apr_time_sec(valid_for) + MD_SECS_PER_DAY - 1)/ MD_SECS_PER_DAY);
+    if (!X509_set_notBefore(x, ASN1_TIME_set(NULL, time(NULL)))) {
+        rv = APR_EGENERAL; goto out;
+    }
+    if (!X509_set_notAfter(x, ASN1_TIME_adj(NULL, time(NULL), days, 0))) {
+        rv = APR_EGENERAL; goto out;
+    }
+
+out:
+    *px = (APR_SUCCESS == rv)? x : NULL;
+    if (APR_SUCCESS != rv && x) X509_free(x);
+    if (big_rnd) BN_free(big_rnd);
+    if (asn1_rnd) ASN1_INTEGER_free(asn1_rnd);
+    if (n) X509_NAME_free(n);
+    return rv;
+}
+
+apr_status_t md_cert_self_sign(md_cert_t **pcert, const char *cn, 
+                               apr_array_header_t *domains, md_pkey_t *pkey,
+                               apr_interval_time_t valid_for, apr_pool_t *p)
+{
+    X509 *x;
+    md_cert_t *cert = NULL;
+    apr_status_t rv;
+    
+    assert(domains);
+
+    if (APR_SUCCESS != (rv = mk_x509(&x, pkey, cn, valid_for, p))) goto out;
+    
+    /* add the domain as alt name */
+    if (APR_SUCCESS != (rv = add_ext(x, NID_subject_alt_name, alt_names(domains, p), p))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: set alt_name ext", cn);
+        goto out;
+    }
+
+    /* keyUsage, ExtendedKeyUsage */
+
+    if (APR_SUCCESS != (rv = add_ext(x, NID_key_usage, "critical,digitalSignature", p))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: set keyUsage", cn);
+        goto out;
+    }
+    if (APR_SUCCESS != (rv = add_ext(x, NID_ext_key_usage, "serverAuth", p))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: set extKeyUsage", cn);
+        goto out;
+    }
+
+    /* sign with same key */
+    if (!X509_sign(x, pkey->pkey, pkey_get_MD(pkey))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: sign x509", cn);
+        rv = APR_EGENERAL; goto out;
+    }
+
+    cert = md_cert_make(p, x);
+    rv = APR_SUCCESS;
+    
+out:
+    *pcert = (APR_SUCCESS == rv)? cert : NULL;
+    if (!cert && x) X509_free(x);
+    return rv;
+}
+
+#define MD_OID_ACME_VALIDATION_NUM          "1.3.6.1.5.5.7.1.31"
+#define MD_OID_ACME_VALIDATION_SNAME        "pe-acmeIdentifier"
+#define MD_OID_ACME_VALIDATION_LNAME        "ACME Identifier" 
+
+static int get_acme_validation_nid(void)
+{
+    int nid = OBJ_txt2nid(MD_OID_ACME_VALIDATION_NUM);
+    if (NID_undef == nid) {
+        nid = OBJ_create(MD_OID_ACME_VALIDATION_NUM, 
+                         MD_OID_ACME_VALIDATION_SNAME, MD_OID_ACME_VALIDATION_LNAME);
+    }
+    return nid;
+}
+
+apr_status_t md_cert_make_tls_alpn_01(md_cert_t **pcert, const char *domain, 
+                                      const char *acme_id, md_pkey_t *pkey, 
+                                      apr_interval_time_t valid_for, apr_pool_t *p)
+{
+    X509 *x;
+    md_cert_t *cert = NULL;
+    const char *alts;
+    apr_status_t rv;
+
+    if (APR_SUCCESS != (rv = mk_x509(&x, pkey, "tls-alpn-01-challenge", valid_for, p))) goto out;
+    
+    /* add the domain as alt name */
+    alts = apr_psprintf(p, "DNS:%s", domain);
+    if (APR_SUCCESS != (rv = add_ext(x, NID_subject_alt_name, alts, p))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: set alt_name ext", domain);
+        goto out;
+    }
+
+    if (APR_SUCCESS != (rv = add_ext(x, get_acme_validation_nid(), acme_id, p))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: set pe-acmeIdentifier", domain);
+        goto out;
+    }
+
+    /* sign with same key */
+    if (!X509_sign(x, pkey->pkey, pkey_get_MD(pkey))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "%s: sign x509", domain);
+        rv = APR_EGENERAL; goto out;
+    }
+
+    cert = md_cert_make(p, x);
+    rv = APR_SUCCESS;
+    
+out:
+    if (!cert && x) {
+        X509_free(x);
+    }
+    *pcert = (APR_SUCCESS == rv)? cert : NULL;
+    return rv;
+}
+
+#define MD_OID_CT_SCTS_NUM          "1.3.6.1.4.1.11129.2.4.2"
+#define MD_OID_CT_SCTS_SNAME        "CT-SCTs"
+#define MD_OID_CT_SCTS_LNAME        "CT Certificate SCTs" 
+
+#ifndef OPENSSL_NO_CT
+static int get_ct_scts_nid(void)
+{
+    int nid = OBJ_txt2nid(MD_OID_CT_SCTS_NUM);
+    if (NID_undef == nid) {
+        nid = OBJ_create(MD_OID_CT_SCTS_NUM, 
+                         MD_OID_CT_SCTS_SNAME, MD_OID_CT_SCTS_LNAME);
+    }
+    return nid;
+}
+#endif
+
+const char *md_nid_get_sname(int nid)
+{
+    return OBJ_nid2sn(nid);
+}
+
+const char *md_nid_get_lname(int nid)
+{
+    return OBJ_nid2ln(nid);
+}
+
+apr_status_t md_cert_get_ct_scts(apr_array_header_t *scts, apr_pool_t *p, const md_cert_t *cert)
+{
+#ifndef OPENSSL_NO_CT
+    int nid, i, idx, critical;
+    STACK_OF(SCT) *sct_list;
+    SCT *sct_handle;
+    md_sct *sct;
+    size_t len;
+    const char *data;
+    
+    nid = get_ct_scts_nid();
+    if (NID_undef == nid) return APR_ENOTIMPL;
+
+    idx = -1;
+    while (1) {
+        sct_list = X509_get_ext_d2i(cert->x509, nid, &critical, &idx);
+        if (sct_list) {
+            for (i = 0; i < sk_SCT_num(sct_list); i++) {
+               sct_handle = sk_SCT_value(sct_list, i);
+                if (sct_handle) {
+                    sct = apr_pcalloc(p, sizeof(*sct));
+                    sct->version = SCT_get_version(sct_handle);
+                    sct->timestamp = apr_time_from_msec(SCT_get_timestamp(sct_handle));
+                    len = SCT_get0_log_id(sct_handle, (unsigned char**)&data);
+                    sct->logid = md_data_make_pcopy(p, data, len);
+                    sct->signature_type_nid = SCT_get_signature_nid(sct_handle);
+                    len = SCT_get0_signature(sct_handle,  (unsigned char**)&data);
+                    sct->signature = md_data_make_pcopy(p, data, len);
+                    
+                    APR_ARRAY_PUSH(scts, md_sct*) = sct;
+                }
+            }
+        }
+        if (idx < 0) break;
+    }
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, p, "ct_sct, found %d SCT extensions", scts->nelts);
+    return APR_SUCCESS;
+#else
+    (void)scts;
+    (void)p;
+    (void)cert;
+    return APR_ENOTIMPL;
+#endif
+}
+
+apr_status_t md_cert_get_ocsp_responder_url(const char **purl, apr_pool_t *p, const md_cert_t *cert)
+{
+    STACK_OF(OPENSSL_STRING) *ssk;
+    apr_status_t rv = APR_SUCCESS;
+    const char *url = NULL;
+
+    ssk = X509_get1_ocsp(md_cert_get_X509(cert));
+    if (!ssk) {
+        rv = APR_ENOENT;
+        goto cleanup;
+    }
+    url = apr_pstrdup(p, sk_OPENSSL_STRING_value(ssk, 0));
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, p, "ocsp responder found '%s'", url);
+
+cleanup:
+    if (ssk) X509_email_free(ssk);
+    *purl = url;
+    return rv;
+}
+
+apr_status_t md_check_cert_and_pkey(struct apr_array_header_t *certs, md_pkey_t *pkey)
+{
+    const md_cert_t *cert;
+
+    if (certs->nelts == 0) {
+        return APR_ENOENT;
+    }
+
+    cert = APR_ARRAY_IDX(certs, 0, const md_cert_t*);
+
+    if (1 != X509_check_private_key(cert->x509, pkey->pkey)) {
+        return APR_EGENERAL;
+    }
+
+    return APR_SUCCESS;
+}
diff --git a/modules/md/md_crypt.h b/modules/md/md_crypt.h
new file mode 100644
index 0000000..a892e00
--- /dev/null
+++ b/modules/md/md_crypt.h
@@ -0,0 +1,253 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_crypt_h
+#define mod_md_md_crypt_h
+
+#include <apr_file_io.h>
+
+struct apr_array_header_t;
+struct md_t;
+struct md_http_response_t;
+struct md_cert_t;
+struct md_pkey_t;
+struct md_data_t;
+struct md_timeperiod_t;
+
+/**************************************************************************************************/
+/* random */
+
+apr_status_t md_rand_bytes(unsigned char *buf, apr_size_t len, apr_pool_t *p);
+
+apr_time_t md_asn1_generalized_time_get(void *ASN1_GENERALIZEDTIME);
+
+/**************************************************************************************************/
+/* digests */
+apr_status_t md_crypt_sha256_digest64(const char **pdigest64, apr_pool_t *p, 
+                                      const struct md_data_t *data);
+apr_status_t md_crypt_sha256_digest_hex(const char **pdigesthex, apr_pool_t *p, 
+                                        const struct md_data_t *data);
+
+/**************************************************************************************************/
+/* private keys */
+
+typedef struct md_pkey_t md_pkey_t;
+
+typedef enum {
+    MD_PKEY_TYPE_DEFAULT,
+    MD_PKEY_TYPE_RSA,
+    MD_PKEY_TYPE_EC,
+} md_pkey_type_t;
+
+typedef struct md_pkey_rsa_params_t {
+    apr_uint32_t bits;
+} md_pkey_rsa_params_t;
+
+typedef struct md_pkey_ec_params_t {
+    const char *curve;
+} md_pkey_ec_params_t;
+
+typedef struct md_pkey_spec_t {
+    md_pkey_type_t type;
+    union {
+        md_pkey_rsa_params_t rsa;
+        md_pkey_ec_params_t ec;
+    } params;
+} md_pkey_spec_t;
+
+typedef struct md_pkeys_spec_t {
+    apr_pool_t *p;
+    struct apr_array_header_t *specs;
+} md_pkeys_spec_t;
+
+apr_status_t md_crypt_init(apr_pool_t *pool);
+
+const char *md_pkey_spec_name(const md_pkey_spec_t *spec);
+
+md_pkeys_spec_t *md_pkeys_spec_make(apr_pool_t *p);
+void md_pkeys_spec_add_default(md_pkeys_spec_t *pks);
+int md_pkeys_spec_contains_rsa(md_pkeys_spec_t *pks);
+void md_pkeys_spec_add_rsa(md_pkeys_spec_t *pks, unsigned int bits);
+int md_pkeys_spec_contains_ec(md_pkeys_spec_t *pks, const char *curve);
+void md_pkeys_spec_add_ec(md_pkeys_spec_t *pks, const char *curve);
+int md_pkeys_spec_eq(md_pkeys_spec_t *pks1, md_pkeys_spec_t *pks2);
+md_pkeys_spec_t *md_pkeys_spec_clone(apr_pool_t *p, const md_pkeys_spec_t *pks);
+int md_pkeys_spec_is_empty(const md_pkeys_spec_t *pks);
+md_pkey_spec_t *md_pkeys_spec_get(const md_pkeys_spec_t *pks, int index);
+int md_pkeys_spec_count(const md_pkeys_spec_t *pks);
+void md_pkeys_spec_add(md_pkeys_spec_t *pks, md_pkey_spec_t *spec);
+
+struct md_json_t *md_pkey_spec_to_json(const md_pkey_spec_t *spec, apr_pool_t *p);
+md_pkey_spec_t *md_pkey_spec_from_json(struct md_json_t *json, apr_pool_t *p);
+struct md_json_t *md_pkeys_spec_to_json(const md_pkeys_spec_t *pks, apr_pool_t *p);
+md_pkeys_spec_t *md_pkeys_spec_from_json(struct md_json_t *json, apr_pool_t *p);
+
+
+apr_status_t md_pkey_gen(md_pkey_t **ppkey, apr_pool_t *p, md_pkey_spec_t *key_props);
+void md_pkey_free(md_pkey_t *pkey);
+
+const char *md_pkey_get_rsa_e64(md_pkey_t *pkey, apr_pool_t *p);
+const char *md_pkey_get_rsa_n64(md_pkey_t *pkey, apr_pool_t *p);
+
+apr_status_t md_pkey_fload(md_pkey_t **ppkey, apr_pool_t *p, 
+                           const char *pass_phrase, apr_size_t pass_len,
+                           const char *fname);
+apr_status_t md_pkey_fsave(md_pkey_t *pkey, apr_pool_t *p, 
+                           const char *pass_phrase, apr_size_t pass_len, 
+                           const char *fname, apr_fileperms_t perms);
+
+apr_status_t md_crypt_sign64(const char **psign64, md_pkey_t *pkey, apr_pool_t *p, 
+                             const char *d, size_t dlen);
+
+void *md_pkey_get_EVP_PKEY(struct md_pkey_t *pkey);
+
+apr_status_t md_crypt_hmac64(const char **pmac64, const struct md_data_t *hmac_key,
+                             apr_pool_t *p, const char *d, size_t dlen);
+
+/**
+ * Read a private key from a http response.
+ */
+apr_status_t md_pkey_read_http(md_pkey_t **ppkey, apr_pool_t *pool,
+                               const struct md_http_response_t *res);
+
+/**************************************************************************************************/
+/* X509 certificates */
+
+typedef struct md_cert_t md_cert_t;
+
+typedef enum {
+    MD_CERT_UNKNOWN,
+    MD_CERT_VALID,
+    MD_CERT_EXPIRED
+} md_cert_state_t;
+
+/**
+ * Create a holder of the certificate that will free its memory when the
+ * pool is destroyed.
+ */
+md_cert_t *md_cert_make(apr_pool_t *p, void *x509);
+
+/**
+ * Wrap a x509 certificate into our own structure, without taking ownership
+ * of its memory. The caller remains responsible.
+ */
+md_cert_t *md_cert_wrap(apr_pool_t *p, void *x509);
+
+void *md_cert_get_X509(const md_cert_t *cert);
+
+apr_status_t md_cert_fload(md_cert_t **pcert, apr_pool_t *p, const char *fname);
+apr_status_t md_cert_fsave(md_cert_t *cert, apr_pool_t *p, 
+                           const char *fname, apr_fileperms_t perms);
+
+/**
+ * Read a x509 certificate from a http response.
+ * Will return APR_ENOENT if content-type is not recognized (currently
+ * only "application/pkix-cert" is supported).
+ */
+apr_status_t md_cert_read_http(md_cert_t **pcert, apr_pool_t *pool, 
+                               const struct md_http_response_t *res);
+
+/**
+ * Read at least one certificate from the given PEM data.
+ */
+apr_status_t md_cert_read_chain(apr_array_header_t *chain, apr_pool_t *p,
+                                const char *pem, apr_size_t pem_len);
+
+/**
+ * Read one or even a chain of certificates from a http response.
+ * Will return APR_ENOENT if content-type is not recognized (currently
+ * supports only "application/pem-certificate-chain" and "application/pkix-cert").
+ * @param chain    must be non-NULL, retrieved certificates will be added.
+ */
+apr_status_t md_cert_chain_read_http(struct apr_array_header_t *chain,
+                                     apr_pool_t *pool, const struct md_http_response_t *res);
+
+md_cert_state_t md_cert_state_get(const md_cert_t *cert);
+int md_cert_is_valid_now(const md_cert_t *cert);
+int md_cert_has_expired(const md_cert_t *cert);
+int md_cert_covers_domain(md_cert_t *cert, const char *domain_name);
+int md_cert_covers_md(md_cert_t *cert, const struct md_t *md);
+int md_cert_must_staple(const md_cert_t *cert);
+apr_time_t md_cert_get_not_after(const md_cert_t *cert);
+apr_time_t md_cert_get_not_before(const md_cert_t *cert);
+struct md_timeperiod_t md_cert_get_valid(const md_cert_t *cert);
+
+/**
+ * Return != 0 iff the hash values of the certificates are equal.
+ */
+int md_certs_are_equal(const md_cert_t *a, const md_cert_t *b);
+
+apr_status_t md_cert_get_issuers_uri(const char **puri, const md_cert_t *cert, apr_pool_t *p);
+apr_status_t md_cert_get_alt_names(apr_array_header_t **pnames, const md_cert_t *cert, apr_pool_t *p);
+
+apr_status_t md_cert_to_base64url(const char **ps64, const md_cert_t *cert, apr_pool_t *p);
+apr_status_t md_cert_from_base64url(md_cert_t **pcert, const char *s64, apr_pool_t *p);
+
+apr_status_t md_cert_to_sha256_digest(struct md_data_t **pdigest, const md_cert_t *cert, apr_pool_t *p);
+apr_status_t md_cert_to_sha256_fingerprint(const char **pfinger, const md_cert_t *cert, apr_pool_t *p);
+
+const char *md_cert_get_serial_number(const md_cert_t *cert, apr_pool_t *p);
+
+apr_status_t md_chain_fload(struct apr_array_header_t **pcerts, 
+                            apr_pool_t *p, const char *fname);
+apr_status_t md_chain_fsave(struct apr_array_header_t *certs, 
+                            apr_pool_t *p, const char *fname, apr_fileperms_t perms);
+apr_status_t md_chain_fappend(struct apr_array_header_t *certs, 
+                              apr_pool_t *p, const char *fname);
+
+apr_status_t md_cert_req_create(const char **pcsr_der_64, const char *name,
+                                apr_array_header_t *domains, int must_staple, 
+                                md_pkey_t *pkey, apr_pool_t *p);
+
+/**
+ * Create a self-signed cerftificate with the given cn, key and list
+ * of alternate domain names.
+ */
+apr_status_t md_cert_self_sign(md_cert_t **pcert, const char *cn, 
+                               struct apr_array_header_t *domains, md_pkey_t *pkey,
+                               apr_interval_time_t valid_for, apr_pool_t *p);
+   
+/**
+ * Create a certificate for answering "tls-alpn-01" ACME challenges 
+ * (see <https://tools.ietf.org/html/draft-ietf-acme-tls-alpn-01>).
+ */
+apr_status_t md_cert_make_tls_alpn_01(md_cert_t **pcert, const char *domain, 
+                                      const char *acme_id, md_pkey_t *pkey, 
+                                      apr_interval_time_t valid_for, apr_pool_t *p);
+
+apr_status_t md_cert_get_ct_scts(apr_array_header_t *scts, apr_pool_t *p, const md_cert_t *cert);
+
+apr_status_t md_cert_get_ocsp_responder_url(const char **purl, apr_pool_t *p, const md_cert_t *cert);
+
+apr_status_t md_check_cert_and_pkey(struct apr_array_header_t *certs, md_pkey_t *pkey);
+
+
+/**************************************************************************************************/
+/* X509 certificate transparency */
+
+const char *md_nid_get_sname(int nid);
+const char *md_nid_get_lname(int nid);
+
+typedef struct md_sct md_sct;
+struct md_sct {
+    int version;
+    apr_time_t timestamp;
+    struct md_data_t *logid;
+    int signature_type_nid;
+    struct md_data_t *signature;
+};
+
+#endif /* md_crypt_h */
diff --git a/modules/md/md_curl.c b/modules/md/md_curl.c
new file mode 100644
index 0000000..217e857
--- /dev/null
+++ b/modules/md/md_curl.c
@@ -0,0 +1,653 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+
+#include <curl/curl.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_buckets.h>
+
+#include "md_http.h"
+#include "md_log.h"
+#include "md_util.h"
+#include "md_curl.h"
+
+/**************************************************************************************************/
+/* md_http curl implementation */
+
+
+static apr_status_t curl_status(unsigned int curl_code)
+{
+    switch (curl_code) {
+        case CURLE_OK:                   return APR_SUCCESS;
+        case CURLE_UNSUPPORTED_PROTOCOL: return APR_ENOTIMPL; 
+        case CURLE_NOT_BUILT_IN:         return APR_ENOTIMPL; 
+        case CURLE_URL_MALFORMAT:        return APR_EINVAL;
+        case CURLE_COULDNT_RESOLVE_PROXY:return APR_ECONNREFUSED;
+        case CURLE_COULDNT_RESOLVE_HOST: return APR_ECONNREFUSED;
+        case CURLE_COULDNT_CONNECT:      return APR_ECONNREFUSED;
+        case CURLE_REMOTE_ACCESS_DENIED: return APR_EACCES;
+        case CURLE_OUT_OF_MEMORY:        return APR_ENOMEM;
+        case CURLE_OPERATION_TIMEDOUT:   return APR_TIMEUP;
+        case CURLE_SSL_CONNECT_ERROR:    return APR_ECONNABORTED;
+        case CURLE_AGAIN:                return APR_EAGAIN;
+        default:                         return APR_EGENERAL;
+    }
+}
+
+typedef struct {
+    CURL *curl;
+    CURLM *curlm;
+    struct curl_slist *req_hdrs;
+    md_http_response_t *response;
+    apr_status_t rv;
+    int status_fired;
+} md_curl_internals_t;
+
+static size_t req_data_cb(void *data, size_t len, size_t nmemb, void *baton)
+{
+    apr_bucket_brigade *body = baton;
+    size_t blen, read_len = 0, max_len = len * nmemb;
+    const char *bdata;
+    char *rdata = data;
+    apr_bucket *b;
+    apr_status_t rv;
+    
+    while (body && !APR_BRIGADE_EMPTY(body) && max_len > 0) {
+        b = APR_BRIGADE_FIRST(body);
+        if (APR_BUCKET_IS_METADATA(b)) {
+            if (APR_BUCKET_IS_EOS(b)) {
+                body = NULL;
+            }
+        }
+        else {
+            rv = apr_bucket_read(b, &bdata, &blen, APR_BLOCK_READ);
+            if (rv == APR_SUCCESS) {
+                if (blen > max_len) {
+                    apr_bucket_split(b, max_len);
+                    blen = max_len;
+                }
+                memcpy(rdata, bdata, blen);
+                read_len += blen;
+                max_len -= blen;
+                rdata += blen;
+            }
+            else {
+                body = NULL;
+                if (!APR_STATUS_IS_EOF(rv)) {
+                    /* everything beside EOF is an error */
+                    read_len = CURL_READFUNC_ABORT;
+                }
+            }
+            
+        }
+        apr_bucket_delete(b);
+    }
+    
+    return read_len;
+}
+
+static size_t resp_data_cb(void *data, size_t len, size_t nmemb, void *baton)
+{
+    md_curl_internals_t *internals = baton;
+    md_http_response_t *res = internals->response;
+    size_t blen = len * nmemb;
+    apr_status_t rv;
+    
+    if (res->body) {
+        if (res->req->resp_limit) {
+            apr_off_t body_len = 0;
+            apr_brigade_length(res->body, 0, &body_len);
+            if (body_len + (apr_off_t)blen > res->req->resp_limit) {
+                return 0; /* signal curl failure */
+            }
+        }
+        rv = apr_brigade_write(res->body, NULL, NULL, (const char *)data, blen);
+        if (rv != APR_SUCCESS) {
+            /* returning anything != blen will make CURL fail this */
+            return 0;
+        }
+    }
+    return blen;
+}
+
+static size_t header_cb(void *buffer, size_t elen, size_t nmemb, void *baton)
+{
+    md_curl_internals_t *internals = baton;
+    md_http_response_t *res = internals->response;
+    size_t len, clen = elen * nmemb;
+    const char *name = NULL, *value = "", *b = buffer;
+    apr_size_t i;
+    
+    len = (clen && b[clen-1] == '\n')? clen-1 : clen;
+    len = (len && b[len-1] == '\r')? len-1 : len;
+    for (i = 0; i < len; ++i) {
+        if (b[i] == ':') {
+            name = apr_pstrndup(res->req->pool, b, i);
+            ++i;
+            while (i < len && b[i] == ' ') {
+                ++i;
+            }
+            if (i < len) {
+                value = apr_pstrndup(res->req->pool, b+i, len - i);
+            }
+            break;
+        }
+    }
+    
+    if (name != NULL) {
+        apr_table_add(res->headers, name, value);
+    }
+    return clen;
+}
+
+typedef struct {
+    md_http_request_t *req;
+    struct curl_slist *hdrs;
+    apr_status_t rv;
+} curlify_hdrs_ctx;
+
+static int curlify_headers(void *baton, const char *key, const char *value)
+{
+    curlify_hdrs_ctx *ctx = baton;
+    const char *s;
+    
+    if (strchr(key, '\r') || strchr(key, '\n')
+        || strchr(value, '\r') || strchr(value, '\n')) {
+        ctx->rv = APR_EINVAL;
+        return 0;
+    }
+    s = apr_psprintf(ctx->req->pool, "%s: %s", key, value);
+    ctx->hdrs = curl_slist_append(ctx->hdrs, s);
+    return 1;
+}
+
+/* Convert timeout values for curl. Since curl uses 0 to disable
+ * timeout, return at least 1 if the apr_time_t value is non-zero. */
+static long timeout_msec(apr_time_t timeout)
+{
+    long ms = (long)apr_time_as_msec(timeout);
+    return ms? ms : (timeout? 1 : 0);
+}
+
+static long timeout_sec(apr_time_t timeout)
+{
+    long s = (long)apr_time_sec(timeout);
+    return s? s : (timeout? 1 : 0);
+}
+
+static int curl_debug_log(CURL *curl, curl_infotype type, char *data, size_t size, void *baton)
+{
+    md_http_request_t *req = baton;
+    
+    (void)curl;
+    switch (type) {
+        case CURLINFO_TEXT:
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, req->pool, 
+                          "req[%d]: info %s", req->id, apr_pstrndup(req->pool, data, size));
+            break;
+        case CURLINFO_HEADER_OUT:
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, req->pool, 
+                          "req[%d]: header --> %s", req->id, apr_pstrndup(req->pool, data, size));
+            break;
+        case CURLINFO_HEADER_IN:
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, req->pool, 
+                          "req[%d]: header <-- %s", req->id, apr_pstrndup(req->pool, data, size));
+            break;
+        case CURLINFO_DATA_OUT:
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, req->pool, 
+                          "req[%d]: data --> %ld bytes", req->id, (long)size);
+            if (md_log_is_level(req->pool, MD_LOG_TRACE5)) {
+                md_data_t d;
+                const char *s;
+                md_data_init(&d, data, size);
+                md_data_to_hex(&s, 0, req->pool, &d);
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE5, 0, req->pool, 
+                              "req[%d]: data(hex) -->  %s", req->id, s);
+            }
+            break;
+        case CURLINFO_DATA_IN:
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, req->pool, 
+                          "req[%d]: data <-- %ld bytes", req->id, (long)size);
+            if (md_log_is_level(req->pool, MD_LOG_TRACE5)) {
+                md_data_t d;
+                const char *s;
+                md_data_init(&d, data, size);
+                md_data_to_hex(&s, 0, req->pool, &d);
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE5, 0, req->pool, 
+                              "req[%d]: data(hex) <-- %s", req->id, s);
+            }
+            break;
+        default:
+            break;
+    }
+    return 0;
+}
+
+static apr_status_t internals_setup(md_http_request_t *req)
+{
+    md_curl_internals_t *internals;
+    CURL *curl;
+    apr_status_t rv = APR_SUCCESS;
+
+    curl = md_http_get_impl_data(req->http);
+    if (!curl) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, req->pool, "creating curl instance");
+        curl = curl_easy_init();
+        if (!curl) {
+            rv = APR_EGENERAL;
+            goto leave;
+        }
+        curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header_cb);
+        curl_easy_setopt(curl, CURLOPT_HEADERDATA, NULL);
+        curl_easy_setopt(curl, CURLOPT_READFUNCTION, req_data_cb);
+        curl_easy_setopt(curl, CURLOPT_READDATA, NULL);
+        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, resp_data_cb);
+        curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
+    }
+    else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, req->pool, "reusing curl instance from http");
+    }
+
+    internals = apr_pcalloc(req->pool, sizeof(*internals));
+    internals->curl = curl;
+        
+    internals->response = apr_pcalloc(req->pool, sizeof(md_http_response_t));
+    internals->response->req = req;
+    internals->response->status = 400;
+    internals->response->headers = apr_table_make(req->pool, 5);
+    internals->response->body = apr_brigade_create(req->pool, req->bucket_alloc);
+    
+    curl_easy_setopt(curl, CURLOPT_URL, req->url);
+    if (!apr_strnatcasecmp("GET", req->method)) {
+        /* nop */
+    }
+    else if (!apr_strnatcasecmp("HEAD", req->method)) {
+        curl_easy_setopt(curl, CURLOPT_NOBODY, 1L);
+    }
+    else if (!apr_strnatcasecmp("POST", req->method)) {
+        curl_easy_setopt(curl, CURLOPT_POST, 1L);
+    }
+    else {
+        curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, req->method);
+    }
+    curl_easy_setopt(curl, CURLOPT_HEADERDATA, internals);
+    curl_easy_setopt(curl, CURLOPT_READDATA, req->body);
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, internals);
+    
+    if (req->timeout.overall > 0) {
+        curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS, timeout_msec(req->timeout.overall));
+    }
+    if (req->timeout.connect > 0) {
+        curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS, timeout_msec(req->timeout.connect));
+    }
+    if (req->timeout.stalled > 0) {
+        curl_easy_setopt(curl, CURLOPT_LOW_SPEED_LIMIT, req->timeout.stall_bytes_per_sec);
+        curl_easy_setopt(curl, CURLOPT_LOW_SPEED_TIME, timeout_sec(req->timeout.stalled));
+    }
+    if (req->ca_file) {
+        curl_easy_setopt(curl, CURLOPT_CAINFO, req->ca_file);
+    }
+    if (req->unix_socket_path) {
+        curl_easy_setopt(curl, CURLOPT_UNIX_SOCKET_PATH, req->unix_socket_path);
+    }
+
+    if (req->body_len >= 0) {
+        /* set the Content-Length */
+        curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)req->body_len);
+        curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE_LARGE, (curl_off_t)req->body_len);
+    }
+    
+    if (req->user_agent) {
+        curl_easy_setopt(curl, CURLOPT_USERAGENT, req->user_agent);
+    }
+    if (req->proxy_url) {
+        curl_easy_setopt(curl, CURLOPT_PROXY, req->proxy_url);
+    }
+    if (!apr_is_empty_table(req->headers)) {
+        curlify_hdrs_ctx ctx;
+        
+        ctx.req = req;
+        ctx.hdrs = NULL;
+        ctx.rv = APR_SUCCESS;
+        apr_table_do(curlify_headers, &ctx, req->headers, NULL);
+        internals->req_hdrs = ctx.hdrs;
+        if (ctx.rv == APR_SUCCESS) {
+            curl_easy_setopt(curl, CURLOPT_HTTPHEADER, internals->req_hdrs);
+        }
+    }
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, req->pool, 
+                  "req[%d]: %s %s", req->id, req->method, req->url);
+    
+    if (md_log_is_level(req->pool, MD_LOG_TRACE4)) {
+        curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
+        curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, curl_debug_log);
+        curl_easy_setopt(curl, CURLOPT_DEBUGDATA, req);
+    }
+    
+leave:
+    req->internals = (APR_SUCCESS == rv)? internals : NULL;
+    return rv;
+}
+
+static apr_status_t update_status(md_http_request_t *req)
+{
+    md_curl_internals_t *internals = req->internals;
+    long l;
+    apr_status_t rv = APR_SUCCESS;
+
+    if (internals) {
+        rv = curl_status(curl_easy_getinfo(internals->curl, CURLINFO_RESPONSE_CODE, &l));
+        if (APR_SUCCESS == rv) {
+            internals->response->status = (int)l;
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, req->pool,
+                          "req[%d]: http status is %d",
+                          req->id, internals->response->status);
+        }
+    }
+    return rv;
+}
+
+static void fire_status(md_http_request_t *req, apr_status_t rv)
+{
+    md_curl_internals_t *internals = req->internals;
+        
+    if (internals && !internals->status_fired) {
+        internals->status_fired = 1;
+        
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, req->pool, 
+                      "req[%d] fire callbacks", req->id);
+        if ((APR_SUCCESS == rv) && req->cb.on_response) {
+            rv = req->cb.on_response(internals->response, req->cb.on_response_data);
+        }
+    
+        internals->rv = rv;
+        if (req->cb.on_status) {
+            req->cb.on_status(req, rv, req->cb.on_status_data);
+        }
+    }
+}
+
+static apr_status_t md_curl_perform(md_http_request_t *req)
+{
+    apr_status_t rv = APR_SUCCESS;
+    CURLcode curle;
+    md_curl_internals_t *internals;
+    long l;
+
+    if (APR_SUCCESS != (rv = internals_setup(req))) goto leave;
+    internals = req->internals;
+    
+    curle = curl_easy_perform(internals->curl);
+    
+    rv = curl_status(curle);
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, req->pool, 
+                      "request failed(%d): %s", curle, curl_easy_strerror(curle));
+        goto leave;
+    }
+    
+    rv = curl_status(curl_easy_getinfo(internals->curl, CURLINFO_RESPONSE_CODE, &l));
+    if (APR_SUCCESS == rv) {
+        internals->response->status = (int)l;
+    }
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, req->pool, "request <-- %d", 
+                  internals->response->status);
+    
+    if (req->cb.on_response) {
+        rv = req->cb.on_response(internals->response, req->cb.on_response_data);
+        req->cb.on_response = NULL;
+    }
+    
+leave:
+    fire_status(req, rv);
+    md_http_req_destroy(req);
+    return rv;
+}
+
+static md_http_request_t *find_curl_request(apr_array_header_t *requests, CURL *curl)
+{
+    md_http_request_t *req;
+    md_curl_internals_t *internals;
+    int i;
+    
+    for (i = 0; i < requests->nelts; ++i) {
+        req = APR_ARRAY_IDX(requests, i, md_http_request_t*);
+        internals = req->internals;
+        if (internals && internals->curl == curl) {
+            return req;
+        }
+    }
+    return NULL;
+}
+
+static void add_to_curlm(md_http_request_t *req, CURLM *curlm)
+{
+    md_curl_internals_t *internals = req->internals;
+    
+    assert(curlm);
+    assert(internals);
+    if (internals->curlm == NULL) {
+        internals->curlm = curlm;
+    }
+    assert(internals->curlm == curlm);
+    curl_multi_add_handle(curlm, internals->curl);
+}
+
+static void remove_from_curlm_and_destroy(md_http_request_t *req, CURLM *curlm)
+{
+    md_curl_internals_t *internals = req->internals;
+
+    assert(curlm);
+    assert(internals);
+    assert(internals->curlm == curlm);
+    curl_multi_remove_handle(curlm, internals->curl);
+    internals->curlm = NULL;
+    md_http_req_destroy(req);
+}
+    
+static apr_status_t md_curl_multi_perform(md_http_t *http, apr_pool_t *p,
+                                          md_http_next_req *nextreq, void *baton)
+{
+    md_http_t *sub_http;
+    md_http_request_t *req;
+    CURLM *curlm = NULL;
+    CURLMcode mc;
+    struct CURLMsg *curlmsg;
+    apr_array_header_t *http_spares;
+    apr_array_header_t *requests;
+    int i, running, numfds, slowdown, msgcount;
+    apr_status_t rv;
+    
+    http_spares = apr_array_make(p, 10, sizeof(md_http_t*));
+    requests = apr_array_make(p, 10, sizeof(md_http_request_t*));
+    curlm = curl_multi_init();
+    if (!curlm) {
+        rv = APR_ENOMEM;
+        goto leave;
+    }
+    
+    running = 1;
+    slowdown = 0;
+    while(1) {
+        while (1) {
+            /* fetch as many requests as nextreq gives us */
+            if (http_spares->nelts > 0) {
+                sub_http = *(md_http_t **)(apr_array_pop(http_spares));
+            }
+            else {
+                rv = md_http_clone(&sub_http, p, http);
+                if (APR_SUCCESS != rv) {
+                    md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p,
+                                  "multi_perform[%d reqs]: setup failed", requests->nelts);
+                    goto leave;
+                }
+            }
+
+            rv = nextreq(&req, baton, sub_http, requests->nelts);
+            if (APR_STATUS_IS_ENOENT(rv)) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, p,
+                              "multi_perform[%d reqs]: no more requests", requests->nelts);
+                if (!requests->nelts) {
+                    goto leave;
+                }
+                break;
+            }
+            else if (APR_SUCCESS != rv) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, p,
+                              "multi_perform[%d reqs]: nextreq() failed", requests->nelts);
+                APR_ARRAY_PUSH(http_spares, md_http_t*) = sub_http;
+                goto leave;
+            }
+
+            if (APR_SUCCESS != (rv = internals_setup(req))) {
+                if (req->cb.on_status) req->cb.on_status(req, rv, req->cb.on_status_data);
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, p,
+                              "multi_perform[%d reqs]: setup failed", requests->nelts);
+                APR_ARRAY_PUSH(http_spares, md_http_t*) = sub_http;
+                goto leave;
+            }
+
+            APR_ARRAY_PUSH(requests, md_http_request_t*) = req;
+            add_to_curlm(req, curlm);
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, p,
+                          "multi_perform[%d reqs]: added request", requests->nelts);
+        }
+    
+        mc = curl_multi_perform(curlm, &running);
+        if (CURLM_OK == mc) {
+            mc = curl_multi_wait(curlm, NULL, 0, 1000, &numfds);
+            if (numfds) slowdown = 0;
+        }
+        if (CURLM_OK != mc) {
+            rv = APR_ECONNABORTED;
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, 
+                          "multi_perform[%d reqs] failed(%d): %s", 
+                          requests->nelts, mc, curl_multi_strerror(mc));
+            goto leave;
+        }
+        if (!numfds) {
+            /* no activity on any connection, timeout */
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, p, 
+                          "multi_perform[%d reqs]: slowdown %d", requests->nelts, slowdown);
+            if (slowdown) apr_sleep(apr_time_from_msec(100));
+            ++slowdown;
+        }
+
+        /* process status messages, e.g. that a request is done */
+        while (running < requests->nelts) {
+            curlmsg = curl_multi_info_read(curlm, &msgcount);
+            if (!curlmsg) break;
+            if (curlmsg->msg == CURLMSG_DONE) {
+                req = find_curl_request(requests, curlmsg->easy_handle);
+                if (req) {
+                    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, p,
+                                  "multi_perform[%d reqs]: req[%d] done", 
+                                  requests->nelts, req->id);
+                    update_status(req);
+                    fire_status(req, curl_status(curlmsg->data.result));
+                    md_array_remove(requests, req);
+                    sub_http = req->http;
+                    APR_ARRAY_PUSH(http_spares, md_http_t*) = sub_http;
+                    remove_from_curlm_and_destroy(req, curlm);
+                }
+                else {
+                    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, 
+                                  "multi_perform[%d reqs]: req done, but not found by handle", 
+                                  requests->nelts);
+                }
+            }
+        }
+    };
+
+leave:
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, p, 
+                  "multi_perform[%d reqs]: leaving", requests->nelts);
+    for (i = 0; i < requests->nelts; ++i) {
+        req = APR_ARRAY_IDX(requests, i, md_http_request_t*);
+        fire_status(req, APR_SUCCESS);
+        sub_http = req->http;
+        APR_ARRAY_PUSH(http_spares, md_http_t*) = sub_http;
+        remove_from_curlm_and_destroy(req, curlm);
+    }
+    if (curlm) curl_multi_cleanup(curlm);
+    return rv;
+}
+
+static int initialized;
+
+static apr_status_t md_curl_init(void) {
+    if (!initialized) {
+        initialized = 1;
+        curl_global_init(CURL_GLOBAL_DEFAULT);
+    }
+    return APR_SUCCESS;
+}
+
+static void md_curl_req_cleanup(md_http_request_t *req) 
+{
+    md_curl_internals_t *internals = req->internals;
+    if (internals) {
+        if (internals->curl) {
+            CURL *curl = md_http_get_impl_data(req->http);
+            if (curl == internals->curl) {
+                /* NOP: we have this curl at the md_http_t already */
+            }
+            else if (!curl) {
+                /* no curl at the md_http_t yet, install this one */
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, req->pool, "register curl instance at http");
+                md_http_set_impl_data(req->http, internals->curl);
+            }
+            else {
+                /* There already is a curl at the md_http_t and it's not this one. */
+                curl_easy_cleanup(internals->curl);
+            }
+        }
+        if (internals->req_hdrs) curl_slist_free_all(internals->req_hdrs);
+        req->internals = NULL;
+    }
+}
+
+static void md_curl_cleanup(md_http_t *http, apr_pool_t *pool)
+{
+    CURL *curl;
+
+    curl = md_http_get_impl_data(http);
+    if (curl) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, pool, "cleanup curl instance");
+        md_http_set_impl_data(http, NULL);
+        curl_easy_cleanup(curl);
+    }
+}
+
+static md_http_impl_t impl = {
+    md_curl_init,
+    md_curl_req_cleanup,
+    md_curl_perform,
+    md_curl_multi_perform,
+    md_curl_cleanup,
+};
+
+md_http_impl_t * md_curl_get_impl(apr_pool_t *p)
+{
+    /* trigger early global curl init, before we are down a rabbit hole */
+    (void)p;
+    md_curl_init();
+    return &impl;
+}
diff --git a/modules/md/md_curl.h b/modules/md/md_curl.h
new file mode 100644
index 0000000..cbc1dd2
--- /dev/null
+++ b/modules/md/md_curl.h
@@ -0,0 +1,24 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef md_curl_h
+#define md_curl_h
+
+struct md_http_impl;
+
+struct md_http_impl_t * md_curl_get_impl(apr_pool_t *p);
+
+#endif /* md_curl_h */
diff --git a/modules/md/md_event.c b/modules/md/md_event.c
new file mode 100644
index 0000000..c731d55
--- /dev/null
+++ b/modules/md/md_event.c
@@ -0,0 +1,89 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+* contributor license agreements.  See the NOTICE file distributed with
+* this work for additional information regarding copyright ownership.
+* The ASF licenses this file to You under the Apache License, Version 2.0
+* (the "License"); you may not use this file except in compliance with
+* the License.  You may obtain a copy of the License at
+*
+*     http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+#include <assert.h>
+#include <apr_optional.h>
+#include <apr_strings.h>
+
+#include "md.h"
+#include "md_event.h"
+
+
+typedef struct md_subscription {
+    struct md_subscription *next;
+    md_event_cb *cb;
+    void *baton;
+} md_subscription;
+
+static struct {
+    apr_pool_t *p;
+    md_subscription *subs;
+} EVNT;
+
+static apr_status_t cleanup_setup(void *dummy)
+{
+    (void)dummy;
+    memset(&EVNT, 0, sizeof(EVNT));
+    return APR_SUCCESS;
+}
+
+void md_event_init(apr_pool_t *p)
+{
+    memset(&EVNT, 0, sizeof(EVNT));
+    EVNT.p = p;
+    apr_pool_cleanup_register(p, NULL, cleanup_setup, apr_pool_cleanup_null);
+}
+
+void md_event_subscribe(md_event_cb *cb, void *baton)
+{
+    md_subscription *sub;
+    
+    sub = apr_pcalloc(EVNT.p, sizeof(*sub));
+    sub->cb = cb;
+    sub->baton = baton;
+    sub->next = EVNT.subs;
+    EVNT.subs = sub;
+} 
+
+apr_status_t md_event_raise(const char *event, 
+                            const char *mdomain, 
+                            struct md_job_t *job, 
+                            struct md_result_t *result, 
+                            apr_pool_t *p)
+{
+    md_subscription *sub = EVNT.subs;
+    apr_status_t rv;
+
+    while (sub) {
+        rv = sub->cb(event, mdomain, sub->baton, job, result, p);
+        if (APR_SUCCESS != rv) return rv;
+        sub = sub->next;
+    }
+    return APR_SUCCESS;
+}
+
+void md_event_holler(const char *event, 
+                     const char *mdomain, 
+                     struct md_job_t *job, 
+                     struct md_result_t *result, 
+                     apr_pool_t *p)
+{
+    md_subscription *sub = EVNT.subs;
+    while (sub) {
+        sub->cb(event, mdomain, sub->baton, job, result, p);
+        sub = sub->next;
+    }
+}
diff --git a/modules/md/md_event.h b/modules/md/md_event.h
new file mode 100644
index 0000000..e66c3c2
--- /dev/null
+++ b/modules/md/md_event.h
@@ -0,0 +1,46 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+* contributor license agreements.  See the NOTICE file distributed with
+* this work for additional information regarding copyright ownership.
+* The ASF licenses this file to You under the Apache License, Version 2.0
+* (the "License"); you may not use this file except in compliance with
+* the License.  You may obtain a copy of the License at
+*
+*     http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+#ifndef md_event_h
+#define md_event_h
+
+struct md_job_t;
+struct md_result_t;
+
+typedef apr_status_t md_event_cb(const char *event, 
+                                 const char *mdomain, 
+                                 void *baton,
+                                 struct md_job_t *job, 
+                                 struct md_result_t *result, 
+                                 apr_pool_t *p);
+
+void md_event_init(apr_pool_t *p); 
+
+void md_event_subscribe(md_event_cb *cb, void *baton); 
+
+apr_status_t md_event_raise(const char *event, 
+                            const char *mdomain, 
+                            struct md_job_t *job, 
+                            struct md_result_t *result, 
+                            apr_pool_t *p);
+
+void md_event_holler(const char *event, 
+                     const char *mdomain, 
+                     struct md_job_t *job, 
+                     struct md_result_t *result, 
+                     apr_pool_t *p);
+
+#endif /* md_event_h */
diff --git a/modules/md/md_http.c b/modules/md/md_http.c
new file mode 100644
index 0000000..0d21e7b
--- /dev/null
+++ b/modules/md/md_http.c
@@ -0,0 +1,397 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_buckets.h>
+
+#include "md_http.h"
+#include "md_log.h"
+#include "md_util.h"
+
+struct md_http_t {
+    apr_pool_t *pool;
+    apr_bucket_alloc_t *bucket_alloc;
+    int next_id;
+    apr_off_t resp_limit;
+    md_http_impl_t *impl;
+    void *impl_data;         /* to be used by the implementation */
+    const char *user_agent;
+    const char *proxy_url;
+    const char *unix_socket_path;
+    md_http_timeouts_t timeout;
+    const char *ca_file;
+};
+
+static md_http_impl_t *cur_impl;
+static int cur_init_done;
+
+void md_http_use_implementation(md_http_impl_t *impl)
+{
+    if (cur_impl != impl) {
+        cur_impl = impl;
+        cur_init_done = 0;
+    }
+}
+
+static apr_status_t http_cleanup(void *data)
+{
+    md_http_t *http = data;
+    if (http && http->impl && http->impl->cleanup) {
+        http->impl->cleanup(http, http->pool);
+    }
+    return APR_SUCCESS;
+}
+
+apr_status_t md_http_create(md_http_t **phttp, apr_pool_t *p, const char *user_agent,
+                            const char *proxy_url)
+{
+    md_http_t *http;
+    apr_status_t rv = APR_SUCCESS;
+
+    if (!cur_impl) {
+        *phttp = NULL;
+        return APR_ENOTIMPL;
+    }
+    
+    if (!cur_init_done) {
+        if (APR_SUCCESS == (rv = cur_impl->init())) {
+            cur_init_done = 1;
+        }
+        else {
+            return rv;
+        }
+    }
+    
+    http = apr_pcalloc(p, sizeof(*http));
+    http->pool = p;
+    http->impl = cur_impl;
+    http->user_agent = apr_pstrdup(p, user_agent);
+    http->proxy_url = proxy_url? apr_pstrdup(p, proxy_url) : NULL;
+    http->bucket_alloc = apr_bucket_alloc_create(p);
+    if (!http->bucket_alloc) {
+        return APR_EGENERAL;
+    }
+    apr_pool_cleanup_register(p, http, http_cleanup, apr_pool_cleanup_null);
+    *phttp = http;
+    return APR_SUCCESS;
+}
+
+apr_status_t md_http_clone(md_http_t **phttp,
+                           apr_pool_t *p, md_http_t *source_http)
+{
+    apr_status_t rv;
+
+    rv = md_http_create(phttp, p, source_http->user_agent, source_http->proxy_url);
+    if (APR_SUCCESS == rv) {
+        (*phttp)->resp_limit = source_http->resp_limit;
+        (*phttp)->timeout = source_http->timeout;
+        if (source_http->unix_socket_path) {
+            (*phttp)->unix_socket_path = apr_pstrdup(p, source_http->unix_socket_path);
+        }
+        if (source_http->ca_file) {
+            (*phttp)->ca_file = apr_pstrdup(p, source_http->ca_file);
+        }
+    }
+    return rv;
+}
+
+void md_http_set_impl_data(md_http_t *http, void *data)
+{
+    http->impl_data = data;
+}
+
+void *md_http_get_impl_data(md_http_t *http)
+{
+    return http->impl_data;
+}
+
+void md_http_set_response_limit(md_http_t *http, apr_off_t resp_limit)
+{
+    http->resp_limit = resp_limit;
+}
+
+void md_http_set_timeout_default(md_http_t *http, apr_time_t timeout)
+{
+    http->timeout.overall = timeout;
+}
+
+void md_http_set_timeout(md_http_request_t *req, apr_time_t timeout)
+{
+    req->timeout.overall = timeout;
+}
+
+void md_http_set_connect_timeout_default(md_http_t *http, apr_time_t timeout)
+{
+    http->timeout.connect = timeout;
+}
+
+void md_http_set_connect_timeout(md_http_request_t *req, apr_time_t timeout)
+{
+    req->timeout.connect = timeout;
+}
+
+void md_http_set_stalling_default(md_http_t *http, long bytes_per_sec, apr_time_t timeout)
+{
+    http->timeout.stall_bytes_per_sec = bytes_per_sec;
+    http->timeout.stalled = timeout;
+}
+
+void md_http_set_stalling(md_http_request_t *req, long bytes_per_sec, apr_time_t timeout)
+{
+    req->timeout.stall_bytes_per_sec = bytes_per_sec;
+    req->timeout.stalled = timeout;
+}
+
+void md_http_set_ca_file(md_http_t *http, const char *ca_file)
+{
+    http->ca_file = ca_file;
+}
+
+void md_http_set_unix_socket_path(md_http_t *http, const char *path)
+{
+    http->unix_socket_path = path;
+}
+
+static apr_status_t req_set_body(md_http_request_t *req, const char *content_type,
+                                 apr_bucket_brigade *body, apr_off_t body_len,
+                                 int detect_len)
+{
+    apr_status_t rv = APR_SUCCESS;
+    
+    if (body && detect_len) {
+        rv = apr_brigade_length(body, 1, &body_len);
+        if (rv != APR_SUCCESS) {
+            return rv;
+        }
+    }
+
+    req->body = body;
+    req->body_len = body? body_len : 0;
+    if (content_type) {
+        apr_table_set(req->headers, "Content-Type", content_type); 
+    }
+    else {
+        apr_table_unset(req->headers, "Content-Type"); 
+    }
+    return rv;
+}
+
+static apr_status_t req_set_body_data(md_http_request_t *req, const char *content_type,
+                                      const md_data_t *body)
+{
+    apr_bucket_brigade *bbody = NULL;
+    apr_status_t rv;
+    
+    if (body && body->len > 0) {
+        bbody = apr_brigade_create(req->pool, req->http->bucket_alloc);
+        rv = apr_brigade_write(bbody, NULL, NULL, body->data, body->len);
+        if (rv != APR_SUCCESS) {
+            return rv;
+        }
+    }
+    return req_set_body(req, content_type, bbody, body? (apr_off_t)body->len : 0, 0);
+}
+
+static apr_status_t req_create(md_http_request_t **preq, md_http_t *http, 
+                               const char *method, const char *url, 
+                               struct apr_table_t *headers)
+{
+    md_http_request_t *req;
+    apr_pool_t *pool;
+    apr_status_t rv;
+    
+    rv = apr_pool_create(&pool, http->pool);
+    if (rv != APR_SUCCESS) {
+        return rv;
+    }
+    apr_pool_tag(pool, "md_http_req");
+    
+    req = apr_pcalloc(pool, sizeof(*req));
+    req->pool = pool;
+    req->id = http->next_id++;
+    req->bucket_alloc = http->bucket_alloc;
+    req->http = http;
+    req->method = method;
+    req->url = url;
+    req->headers = headers? apr_table_copy(req->pool, headers) : apr_table_make(req->pool, 5);
+    req->resp_limit = http->resp_limit;
+    req->user_agent = http->user_agent;
+    req->proxy_url = http->proxy_url;
+    req->timeout = http->timeout;
+    req->ca_file = http->ca_file;
+    req->unix_socket_path = http->unix_socket_path;
+    *preq = req;
+    return rv;
+}
+
+void md_http_req_destroy(md_http_request_t *req) 
+{
+    if (req->internals) {
+        req->http->impl->req_cleanup(req);
+        req->internals = NULL;
+    }
+    apr_pool_destroy(req->pool);
+}
+
+void md_http_set_on_status_cb(md_http_request_t *req, md_http_status_cb *cb, void *baton)
+{
+    req->cb.on_status = cb;
+    req->cb.on_status_data = baton;
+}
+
+void md_http_set_on_response_cb(md_http_request_t *req, md_http_response_cb *cb, void *baton)
+{
+    req->cb.on_response = cb;
+    req->cb.on_response_data = baton;
+}
+
+apr_status_t md_http_perform(md_http_request_t *req)
+{
+    return req->http->impl->perform(req);
+}
+
+typedef struct {
+    md_http_next_req *nextreq;
+    void *baton;
+} nextreq_proxy_t;
+
+static apr_status_t proxy_nextreq(md_http_request_t **preq, void *baton, 
+                                      md_http_t *http, int in_flight)
+{
+    nextreq_proxy_t *proxy = baton;
+    
+    return proxy->nextreq(preq, proxy->baton, http, in_flight);
+}
+
+apr_status_t md_http_multi_perform(md_http_t *http, md_http_next_req *nextreq, void *baton)
+{
+    nextreq_proxy_t proxy;
+    
+    proxy.nextreq = nextreq;
+    proxy.baton = baton;
+    return http->impl->multi_perform(http, http->pool, proxy_nextreq, &proxy);
+}
+
+apr_status_t md_http_GET_create(md_http_request_t **preq, md_http_t *http, const char *url, 
+                                struct apr_table_t *headers)
+{
+    md_http_request_t *req;
+    apr_status_t rv;
+    
+    rv = req_create(&req, http, "GET", url, headers);
+    *preq = (APR_SUCCESS == rv)? req : NULL;
+    return rv;
+}
+
+apr_status_t md_http_HEAD_create(md_http_request_t **preq, md_http_t *http, const char *url, 
+                                 struct apr_table_t *headers)
+{
+    md_http_request_t *req;
+    apr_status_t rv;
+    
+    rv = req_create(&req, http, "HEAD", url, headers);
+    *preq = (APR_SUCCESS == rv)? req : NULL;
+    return rv;
+}
+
+apr_status_t md_http_POST_create(md_http_request_t **preq, md_http_t *http, const char *url, 
+                                 struct apr_table_t *headers, const char *content_type, 
+                                 struct apr_bucket_brigade *body, int detect_len)
+{
+    md_http_request_t *req;
+    apr_status_t rv;
+    
+    rv = req_create(&req, http, "POST", url, headers);
+    if (APR_SUCCESS == rv) {
+        rv = req_set_body(req, content_type, body, -1, detect_len);
+    }
+    *preq = (APR_SUCCESS == rv)? req : NULL;
+    return rv;
+}
+
+apr_status_t md_http_POSTd_create(md_http_request_t **preq, md_http_t *http, const char *url, 
+                                  struct apr_table_t *headers, const char *content_type, 
+                                  const struct md_data_t *body)
+{
+    md_http_request_t *req;
+    apr_status_t rv;
+    
+    rv = req_create(&req, http, "POST", url, headers);
+    if (APR_SUCCESS != rv) goto cleanup;
+    rv = req_set_body_data(req, content_type, body);
+cleanup:
+    if (APR_SUCCESS == rv) {
+        *preq = req;
+    }
+    else {
+        *preq = NULL;
+        if (req) md_http_req_destroy(req);
+    }
+    return rv;
+}
+
+apr_status_t md_http_GET_perform(struct md_http_t *http, 
+                                 const char *url, struct apr_table_t *headers,
+                                 md_http_response_cb *cb, void *baton)
+{
+    md_http_request_t *req;
+    apr_status_t rv;
+
+    rv = md_http_GET_create(&req, http, url, headers);
+    if (APR_SUCCESS == rv) md_http_set_on_response_cb(req, cb, baton);
+    return (APR_SUCCESS == rv)? md_http_perform(req) : rv;
+}
+
+apr_status_t md_http_HEAD_perform(struct md_http_t *http, 
+                                  const char *url, struct apr_table_t *headers,
+                                  md_http_response_cb *cb, void *baton)
+{
+    md_http_request_t *req;
+    apr_status_t rv;
+
+    rv = md_http_HEAD_create(&req, http, url, headers);
+    if (APR_SUCCESS == rv) md_http_set_on_response_cb(req, cb, baton);
+    return (APR_SUCCESS == rv)? md_http_perform(req) : rv;
+}
+
+apr_status_t md_http_POST_perform(struct md_http_t *http, const char *url, 
+                                  struct apr_table_t *headers, const char *content_type, 
+                                  apr_bucket_brigade *body, int detect_len, 
+                                  md_http_response_cb *cb, void *baton)
+{
+    md_http_request_t *req;
+    apr_status_t rv;
+
+    rv = md_http_POST_create(&req, http, url, headers, content_type, body, detect_len);
+    if (APR_SUCCESS == rv) md_http_set_on_response_cb(req, cb, baton);
+    return (APR_SUCCESS == rv)? md_http_perform(req) : rv;
+}
+
+apr_status_t md_http_POSTd_perform(md_http_t *http, const char *url, 
+                                   struct apr_table_t *headers, const char *content_type, 
+                                   const md_data_t *body, 
+                                   md_http_response_cb *cb, void *baton)
+{
+    md_http_request_t *req;
+    apr_status_t rv;
+
+    rv = md_http_POSTd_create(&req, http, url, headers, content_type, body);
+    if (APR_SUCCESS == rv) md_http_set_on_response_cb(req, cb, baton);
+    return (APR_SUCCESS == rv)? md_http_perform(req) : rv;
+}
diff --git a/modules/md/md_http.h b/modules/md/md_http.h
new file mode 100644
index 0000000..2f250f6
--- /dev/null
+++ b/modules/md/md_http.h
@@ -0,0 +1,272 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_http_h
+#define mod_md_md_http_h
+
+struct apr_table_t;
+struct apr_bucket_brigade;
+struct apr_bucket_alloc_t;
+struct md_data_t;
+
+typedef struct md_http_t md_http_t;
+
+typedef struct md_http_request_t md_http_request_t;
+typedef struct md_http_response_t md_http_response_t;
+
+/**
+ * Callback invoked once per request, either when an error was encountered
+ * or when everything succeeded and the request is about to be released. Only
+ * in the last case will the status be APR_SUCCESS.
+ */
+typedef apr_status_t md_http_status_cb(const md_http_request_t *req, apr_status_t status, void *data);
+
+/**
+ * Callback invoked when the complete response has been received.
+ */
+typedef apr_status_t md_http_response_cb(const md_http_response_t *res, void *data);
+
+typedef struct md_http_callbacks_t md_http_callbacks_t;
+struct md_http_callbacks_t {
+    md_http_status_cb *on_status;
+    void *on_status_data;
+    md_http_response_cb *on_response;
+    void *on_response_data;
+};
+
+typedef struct md_http_timeouts_t md_http_timeouts_t;
+struct md_http_timeouts_t {
+    apr_time_t overall;
+    apr_time_t connect;
+    long stall_bytes_per_sec;
+    apr_time_t stalled;
+};
+
+struct md_http_request_t {
+    md_http_t *http;
+    apr_pool_t *pool;
+    int id;
+    struct apr_bucket_alloc_t *bucket_alloc;
+    const char *method;
+    const char *url;
+    const char *user_agent;
+    const char *proxy_url;
+    const char *ca_file;
+    const char *unix_socket_path;
+    apr_table_t *headers;
+    struct apr_bucket_brigade *body;
+    apr_off_t body_len;
+    apr_off_t resp_limit;
+    md_http_timeouts_t timeout;
+    md_http_callbacks_t cb;
+    void *internals;
+};
+
+struct md_http_response_t {
+    md_http_request_t *req;
+    int status;
+    apr_table_t *headers;
+    struct apr_bucket_brigade *body;
+};
+
+apr_status_t md_http_create(md_http_t **phttp, apr_pool_t *p, const char *user_agent,
+                            const char *proxy_url);
+
+void md_http_set_response_limit(md_http_t *http, apr_off_t resp_limit);
+
+/**
+ * Clone a http instance, inheriting all settings from source_http.
+ * The cloned instance is not tied in any way to the source.
+ */
+apr_status_t md_http_clone(md_http_t **phttp,
+                           apr_pool_t *p, md_http_t *source_http);
+
+/**
+ * Set the timeout for the complete request. This needs to take everything from
+ * DNS looksups, to conntects, to transfer of all data into account and should
+ * be sufficiently large.
+ * Set to 0 the have no timeout for this.
+ */
+void md_http_set_timeout_default(md_http_t *http, apr_time_t timeout);
+void md_http_set_timeout(md_http_request_t *req, apr_time_t timeout);
+
+/**
+ * Set the timeout for establishing a connection. 
+ * Set to 0 the have no special timeout for this.
+ */
+void md_http_set_connect_timeout_default(md_http_t *http, apr_time_t timeout);
+void md_http_set_connect_timeout(md_http_request_t *req, apr_time_t timeout);
+
+/**
+ * Set the condition for when a transfer is considered "stalled", e.g. does not
+ * progress at a sufficient rate and will be aborted.
+ * Set to 0 the have no stall detection in place.
+ */
+void md_http_set_stalling_default(md_http_t *http, long bytes_per_sec, apr_time_t timeout);
+void md_http_set_stalling(md_http_request_t *req, long bytes_per_sec, apr_time_t timeout);
+
+/**
+ * Set a CA file (in PERM format) to use for root certificates when
+ * verifying SSL connections. If not set (or set to NULL), the systems
+ * certificate store will be used.
+ */
+void md_http_set_ca_file(md_http_t *http, const char *ca_file);
+
+/**
+ * Set the path of a unix domain socket for use instead of TCP
+ * in a connection. Disable by providing NULL as path.
+ */
+void md_http_set_unix_socket_path(md_http_t *http, const char *path);
+
+/**
+ * Perform the request. Then this function returns, the request and
+ * all its memory has been freed and must no longer be used.
+ */
+apr_status_t md_http_perform(md_http_request_t *request);
+
+/**
+ * Set the callback to be invoked once the status of a request is known.
+ * @param req       the request
+ * @param cb        the callback to invoke on the response
+ * @param baton     data passed to the callback    
+ */
+void md_http_set_on_status_cb(md_http_request_t *req, md_http_status_cb *cb, void *baton);
+
+/**
+ * Set the callback to be invoked when the complete 
+ * response has been successfully received. The HTTP status may
+ * be 500, however.
+ * @param req       the request
+ * @param cb        the callback to invoke on the response
+ * @param baton     data passed to the callback    
+ */
+void md_http_set_on_response_cb(md_http_request_t *req, md_http_response_cb *cb, void *baton);
+
+/**
+ * Create a GET request.
+ * @param preq      the created request after success
+ * @param http      the md_http instance 
+ * @param url       the url to GET
+ * @param headers   request headers
+ */
+apr_status_t md_http_GET_create(md_http_request_t **preq, md_http_t *http, const char *url, 
+                                struct apr_table_t *headers);
+
+/**
+ * Create a HEAD request.
+ * @param preq      the created request after success
+ * @param http      the md_http instance 
+ * @param url       the url to GET
+ * @param headers   request headers
+ */
+apr_status_t md_http_HEAD_create(md_http_request_t **preq, md_http_t *http, const char *url, 
+                                 struct apr_table_t *headers);
+
+/**
+ * Create a POST request with a bucket brigade as request body.
+ * @param preq      the created request after success
+ * @param http      the md_http instance 
+ * @param url       the url to GET
+ * @param headers   request headers
+ * @param content_type the content_type of the body or NULL
+ * @param body      the body of the request or NULL
+ * @param detect_len scan the body to detect its length
+ */
+apr_status_t md_http_POST_create(md_http_request_t **preq, md_http_t *http, const char *url, 
+                                 struct apr_table_t *headers, const char *content_type, 
+                                 struct apr_bucket_brigade *body, int detect_len);
+
+/**
+ * Create a POST request with known request body data.
+ * @param preq      the created request after success
+ * @param http      the md_http instance 
+ * @param url       the url to GET
+ * @param headers   request headers
+ * @param content_type the content_type of the body or NULL
+ * @param body      the body of the request or NULL
+ */
+apr_status_t md_http_POSTd_create(md_http_request_t **preq, md_http_t *http, const char *url, 
+                                  struct apr_table_t *headers, const char *content_type, 
+                                  const struct md_data_t *body);
+
+/*
+ * Convenience functions for create+perform.
+ */
+apr_status_t md_http_GET_perform(md_http_t *http, const char *url, 
+                                 struct apr_table_t *headers,
+                                 md_http_response_cb *cb, void *baton);
+apr_status_t md_http_HEAD_perform(md_http_t *http, const char *url, 
+                                  struct apr_table_t *headers,
+                                  md_http_response_cb *cb, void *baton);
+apr_status_t md_http_POST_perform(md_http_t *http, const char *url, 
+                                  struct apr_table_t *headers, const char *content_type, 
+                                  struct apr_bucket_brigade *body, int detect_len, 
+                                  md_http_response_cb *cb, void *baton);
+apr_status_t md_http_POSTd_perform(md_http_t *http, const char *url, 
+                                   struct apr_table_t *headers, const char *content_type, 
+                                   const struct md_data_t *body, 
+                                   md_http_response_cb *cb, void *baton);
+
+void md_http_req_destroy(md_http_request_t *req);
+
+/** Return the next request for processing on APR_SUCCESS. Return ARP_ENOENT
+ * when no request is available. Anything else is an error.
+ */
+typedef apr_status_t md_http_next_req(md_http_request_t **preq, void *baton, 
+                                      md_http_t *http, int in_flight);
+
+/**
+ * Perform requests in parallel as retrieved from the nextreq function.
+ * There are as many requests in flight as the nextreq functions provides. 
+ *
+ * To limit the number of parallel requests, nextreq should return APR_ENOENT when the limit
+ * is reached. It will be called again when the number of in_flight requests changes.
+ * 
+ * When all requests are done, nextreq will be called one more time. Should it not
+ * return anything, this function returns.
+ */
+apr_status_t md_http_multi_perform(md_http_t *http, md_http_next_req *nextreq, void *baton);
+
+/**************************************************************************************************/
+/* interface to implementation */
+
+typedef apr_status_t md_http_init_cb(void);
+typedef void md_http_cleanup_cb(md_http_t *req, apr_pool_t *p);
+typedef void md_http_req_cleanup_cb(md_http_request_t *req);
+typedef apr_status_t md_http_perform_cb(md_http_request_t *req);
+typedef apr_status_t md_http_multi_perform_cb(md_http_t *http, apr_pool_t *p, 
+                                              md_http_next_req *nextreq, void *baton);
+
+typedef struct md_http_impl_t md_http_impl_t;
+struct md_http_impl_t {
+    md_http_init_cb *init;
+    md_http_req_cleanup_cb *req_cleanup;
+    md_http_perform_cb *perform;
+    md_http_multi_perform_cb *multi_perform;
+    md_http_cleanup_cb *cleanup;
+};
+
+void md_http_use_implementation(md_http_impl_t *impl);
+
+/**
+ * get/set data the implementation wants to remember between requests
+ * in the same md_http_t instance.
+ */
+void md_http_set_impl_data(md_http_t *http, void *data);
+void *md_http_get_impl_data(md_http_t *http);
+
+
+#endif /* md_http_h */
diff --git a/modules/md/md_json.c b/modules/md/md_json.c
new file mode 100644
index 0000000..e0f977e
--- /dev/null
+++ b/modules/md/md_json.c
@@ -0,0 +1,1311 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_buckets.h>
+#include <apr_date.h>
+
+#include "md_json.h"
+#include "md_log.h"
+#include "md_http.h"
+#include "md_time.h"
+#include "md_util.h"
+
+/* jansson thinks everyone compiles with the platform's cc in its fullest capabilities
+ * when undefining their INLINEs, we get static, unused functions, arg 
+ */
+#if defined(__GNUC__)
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+#pragma GCC diagnostic push
+#endif
+#pragma GCC diagnostic ignored "-Wunused-function"
+#pragma GCC diagnostic ignored "-Wunreachable-code"
+#elif defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-function"
+#endif
+
+#include <jansson_config.h>
+#undef  JSON_INLINE
+#define JSON_INLINE 
+#include <jansson.h>
+
+#if defined(__GNUC__)
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+#pragma GCC diagnostic pop
+#endif
+#elif defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
+struct md_json_t {
+    apr_pool_t *p;
+    json_t *j;
+};
+
+/**************************************************************************************************/
+/* lifecycle */
+
+static apr_status_t json_pool_cleanup(void *data)
+{
+    md_json_t *json = data;
+    if (json) {
+        md_json_destroy(json);
+    }
+    return APR_SUCCESS;
+}
+
+static md_json_t *json_create(apr_pool_t *pool, json_t *j)
+{
+    md_json_t *json;
+    
+    if (!j) {
+        apr_abortfunc_t abfn = apr_pool_abort_get(pool);
+        if (abfn) {
+            abfn(APR_ENOMEM);
+        }
+        assert(j != NULL); /* failsafe in case abort is unset */
+    }
+    json = apr_pcalloc(pool, sizeof(*json));
+    json->p = pool;
+    json->j = j;
+    apr_pool_cleanup_register(pool, json, json_pool_cleanup, apr_pool_cleanup_null);
+        
+    return json;
+}
+
+md_json_t *md_json_create(apr_pool_t *pool)
+{
+    return json_create(pool, json_object());
+}
+
+md_json_t *md_json_create_s(apr_pool_t *pool, const char *s)
+{
+    return json_create(pool, json_string(s));
+}
+
+void md_json_destroy(md_json_t *json)
+{
+    if (json && json->j) {
+        assert(json->j->refcount > 0);
+        json_decref(json->j);
+        json->j = NULL;
+    }
+}
+
+md_json_t *md_json_copy(apr_pool_t *pool, const md_json_t *json)
+{
+    return json_create(pool, json_copy(json->j));
+}
+
+md_json_t *md_json_clone(apr_pool_t *pool, const md_json_t *json)
+{
+    return json_create(pool, json_deep_copy(json->j));
+}
+
+/**************************************************************************************************/
+/* selectors */
+
+
+static json_t *jselect(const md_json_t *json, va_list ap)
+{
+    json_t *j;
+    const char *key;
+    
+    j = json->j;
+    key = va_arg(ap, char *);
+    while (key && j) {
+        j = json_object_get(j, key);
+        key = va_arg(ap, char *);
+    }
+    return j;
+}
+
+static json_t *jselect_parent(const char **child_key, int create, md_json_t *json, va_list ap)
+{
+    const char *key, *next;
+    json_t *j, *jn;
+    
+    *child_key = NULL;
+    j = json->j;
+    key = va_arg(ap, char *);
+    while (key && j) {
+        next = va_arg(ap, char *);
+        if (next) {
+            jn = json_object_get(j, key);
+            if (!jn && create) {
+                jn = json_object();
+                json_object_set_new(j, key, jn);
+            }
+            j = jn;
+        }
+        else {
+            *child_key = key;
+        }
+        key = next;
+    }
+    return j;
+}
+
+static apr_status_t jselect_add(json_t *val, md_json_t *json, va_list ap)
+{
+    const char *key;
+    json_t *j, *aj;
+    
+    j = jselect_parent(&key, 1, json, ap);
+    
+    if (!j || !json_is_object(j)) {
+        return APR_EINVAL;
+    }
+    
+    aj = json_object_get(j, key);
+    if (!aj) {
+        aj = json_array();
+        json_object_set_new(j, key, aj);
+    }
+    
+    if (!json_is_array(aj)) {
+        return APR_EINVAL;
+    }
+
+    json_array_append(aj, val);
+    return APR_SUCCESS;
+}
+
+static apr_status_t jselect_insert(json_t *val, size_t index, md_json_t *json, va_list ap)
+{
+    const char *key;
+    json_t *j, *aj;
+    
+    j = jselect_parent(&key, 1, json, ap);
+    
+    if (!j || !json_is_object(j)) {
+        json_decref(val);
+        return APR_EINVAL;
+    }
+    
+    aj = json_object_get(j, key);
+    if (!aj) {
+        aj = json_array();
+        json_object_set_new(j, key, aj);
+    }
+    
+    if (!json_is_array(aj)) {
+        json_decref(val);
+        return APR_EINVAL;
+    }
+
+    if (json_array_size(aj) <= index) {
+        json_array_append(aj, val);
+    }
+    else {
+        json_array_insert(aj, index, val);
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t jselect_set(json_t *val, md_json_t *json, va_list ap)
+{
+    const char *key;
+    json_t *j;
+    
+    j = jselect_parent(&key, 1, json, ap);
+    
+    if (!j) {
+        return APR_EINVAL;
+    }
+    
+    if (key) {
+        if (!json_is_object(j)) {
+            return APR_EINVAL;
+        }
+        json_object_set(j, key, val);
+    }
+    else {
+        /* replace */
+        if (json->j) {
+            json_decref(json->j);
+        }
+        json_incref(val);
+        json->j = val;
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t jselect_set_new(json_t *val, md_json_t *json, va_list ap)
+{
+    const char *key;
+    json_t *j;
+    
+    j = jselect_parent(&key, 1, json, ap);
+    
+    if (!j) {
+        json_decref(val);
+        return APR_EINVAL;
+    }
+    
+    if (key) {
+        if (!json_is_object(j)) {
+            json_decref(val);
+            return APR_EINVAL;
+        }
+        json_object_set_new(j, key, val);
+    }
+    else {
+        /* replace */
+        if (json->j) {
+            json_decref(json->j);
+        }
+        json->j = val;
+    }
+    return APR_SUCCESS;
+}
+
+int md_json_has_key(const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    return j != NULL;
+}
+
+/**************************************************************************************************/
+/* type things */
+
+int md_json_is(const md_json_type_t jtype, md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    switch (jtype) {
+        case MD_JSON_TYPE_OBJECT: return (j && json_is_object(j));
+        case MD_JSON_TYPE_ARRAY: return (j && json_is_array(j));
+        case MD_JSON_TYPE_STRING: return (j && json_is_string(j));
+        case MD_JSON_TYPE_REAL: return (j && json_is_real(j));
+        case MD_JSON_TYPE_INT: return (j && json_is_integer(j));
+        case MD_JSON_TYPE_BOOL: return (j && (json_is_true(j) || json_is_false(j)));
+        case MD_JSON_TYPE_NULL: return (j == NULL);
+    }
+    return 0;
+}
+
+static const char *md_json_type_name(const md_json_t *json)
+{
+    json_t *j = json->j;
+    if (json_is_object(j)) return "object";
+    if (json_is_array(j)) return "array";
+    if (json_is_string(j)) return "string";
+    if (json_is_real(j)) return "real";
+    if (json_is_integer(j)) return "integer";
+    if (json_is_true(j)) return "true";
+    if (json_is_false(j)) return "false";
+    return "unknown";
+}
+
+/**************************************************************************************************/
+/* booleans */
+
+int md_json_getb(const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    return j? json_is_true(j) : 0;
+}
+
+apr_status_t md_json_setb(int value, md_json_t *json, ...)
+{
+    va_list ap;
+    apr_status_t rv;
+    
+    va_start(ap, json);
+    rv = jselect_set_new(json_boolean(value), json, ap);
+    va_end(ap);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* numbers */
+
+double md_json_getn(const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    return (j && json_is_number(j))? json_number_value(j) : 0.0;
+}
+
+apr_status_t md_json_setn(double value, md_json_t *json, ...)
+{
+    va_list ap;
+    apr_status_t rv;
+    
+    va_start(ap, json);
+    rv = jselect_set_new(json_real(value), json, ap);
+    va_end(ap);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* longs */
+
+long md_json_getl(const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    return (long)((j && json_is_number(j))? json_integer_value(j) : 0L);
+}
+
+apr_status_t md_json_setl(long value, md_json_t *json, ...)
+{
+    va_list ap;
+    apr_status_t rv;
+    
+    va_start(ap, json);
+    rv = jselect_set_new(json_integer(value), json, ap);
+    va_end(ap);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* strings */
+
+const char *md_json_gets(const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    return (j && json_is_string(j))? json_string_value(j) : NULL;
+}
+
+const char *md_json_dups(apr_pool_t *p, const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    return (j && json_is_string(j))? apr_pstrdup(p, json_string_value(j)) : NULL;
+}
+
+apr_status_t md_json_sets(const char *value, md_json_t *json, ...)
+{
+    va_list ap;
+    apr_status_t rv;
+    
+    va_start(ap, json);
+    rv = jselect_set_new(json_string(value), json, ap);
+    va_end(ap);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* time */
+
+apr_time_t md_json_get_time(const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    if (!j || !json_is_string(j)) return 0;
+    return apr_date_parse_rfc(json_string_value(j));
+}
+
+apr_status_t md_json_set_time(apr_time_t value, md_json_t *json, ...)
+{
+    char ts[APR_RFC822_DATE_LEN];
+    va_list ap;
+    apr_status_t rv;
+    
+    apr_rfc822_date(ts, value);
+    va_start(ap, json);
+    rv = jselect_set_new(json_string(ts), json, ap);
+    va_end(ap);
+    return rv;
+}
+
+/**************************************************************************************************/
+/* json itself */
+
+md_json_t *md_json_getj(md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    if (j) {
+        if (j == json->j) {
+            return json;
+        }
+        json_incref(j);
+        return json_create(json->p, j);
+    }
+    return NULL;
+}
+
+md_json_t *md_json_dupj(apr_pool_t *p, const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    if (j) {
+        json_incref(j);
+        return json_create(p, j);
+    }
+    return NULL;
+}
+
+const md_json_t *md_json_getcj(const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    if (j) {
+        if (j == json->j) {
+            return json;
+        }
+        json_incref(j);
+        return json_create(json->p, j);
+    }
+    return NULL;
+}
+
+apr_status_t md_json_setj(const md_json_t *value, md_json_t *json, ...)
+{
+    va_list ap;
+    apr_status_t rv;
+    const char *key;
+    json_t *j;
+    
+    if (value) {
+        va_start(ap, json);
+        rv = jselect_set(value->j, json, ap);
+        va_end(ap);
+    }
+    else {
+        va_start(ap, json);
+        j = jselect_parent(&key, 1, json, ap);
+        va_end(ap);
+        
+        if (key && j && !json_is_object(j)) {
+            json_object_del(j, key);
+            rv = APR_SUCCESS;
+        }
+        else {
+            rv = APR_EINVAL;
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_json_addj(const md_json_t *value, md_json_t *json, ...)
+{
+    va_list ap;
+    apr_status_t rv;
+    
+    va_start(ap, json);
+    rv = jselect_add(value->j, json, ap);
+    va_end(ap);
+    return rv;
+}
+
+apr_status_t md_json_insertj(md_json_t *value, size_t index, md_json_t *json, ...)
+{
+    va_list ap;
+    apr_status_t rv;
+    
+    va_start(ap, json);
+    rv = jselect_insert(value->j, index, json, ap);
+    va_end(ap);
+    return rv;
+}
+
+apr_size_t md_json_limita(size_t max_elements, md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    apr_size_t n = 0;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    if (j && json_is_array(j)) {
+        n = json_array_size(j);
+        while (n > max_elements) {
+            json_array_remove(j, n-1);
+            n = json_array_size(j);
+        }
+    }
+    return n;
+}
+
+/**************************************************************************************************/
+/* arrays / objects */
+
+apr_status_t md_json_clr(md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    if (j && json_is_object(j)) {
+        json_object_clear(j);
+    }
+    else if (j && json_is_array(j)) {
+        json_array_clear(j);
+    }
+    return APR_SUCCESS;
+}
+
+apr_status_t md_json_del(md_json_t *json, ...)
+{
+    const char *key;
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect_parent(&key, 0, json, ap);
+    va_end(ap);
+    
+    if (key && j && json_is_object(j)) {
+        json_object_del(j, key);
+    }
+    return APR_SUCCESS;
+}
+
+/**************************************************************************************************/
+/* object strings */
+
+apr_status_t md_json_gets_dict(apr_table_t *dict, const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    if (j && json_is_object(j)) {
+        const char *key;
+        json_t *val;
+        
+        json_object_foreach(j, key, val) {
+            if (json_is_string(val)) {
+                apr_table_set(dict, key, json_string_value(val));
+            }
+        }
+        return APR_SUCCESS;
+    }
+    return APR_ENOENT;
+}
+
+static int object_set(void *data, const char *key, const char *val)
+{
+    json_t *j = data, *nj = json_string(val);
+    json_object_set(j, key, nj);
+    json_decref(nj);
+    return 1;
+}
+ 
+apr_status_t md_json_sets_dict(apr_table_t *dict, md_json_t *json, ...)
+{
+    json_t *nj, *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    if (!j || !json_is_object(j)) {
+        const char *key;
+        
+        va_start(ap, json);
+        j = jselect_parent(&key, 1, json, ap);
+        va_end(ap);
+        
+        if (!key || !j || !json_is_object(j)) {
+            return APR_EINVAL;
+        }
+        nj = json_object();
+        json_object_set_new(j, key, nj);
+        j = nj; 
+    }
+    
+    apr_table_do(object_set, j, dict, NULL);
+    return APR_SUCCESS;
+}
+
+/**************************************************************************************************/
+/* conversions */
+
+apr_status_t md_json_pass_to(void *value, md_json_t *json, apr_pool_t *p, void *baton)
+{
+    (void)p;
+    (void)baton;
+    return md_json_setj(value, json, NULL);
+}
+
+apr_status_t md_json_pass_from(void **pvalue, md_json_t *json, apr_pool_t *p, void *baton)
+{
+    (void)p;
+    (void)baton;
+    *pvalue = json;
+    return APR_SUCCESS;
+}
+
+apr_status_t md_json_clone_to(void *value, md_json_t *json, apr_pool_t *p, void *baton)
+{
+    (void)baton;
+    return md_json_setj(md_json_clone(p, value), json, NULL);
+}
+
+apr_status_t md_json_clone_from(void **pvalue, const md_json_t *json, apr_pool_t *p, void *baton)
+{
+    (void)baton;
+    *pvalue = md_json_clone(p, json);
+    return APR_SUCCESS;
+}
+
+/**************************************************************************************************/
+/* array generic */
+
+apr_status_t md_json_geta(apr_array_header_t *a, md_json_from_cb *cb, void *baton,
+                          const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    apr_status_t rv = APR_SUCCESS;
+    size_t index;
+    json_t *val;
+    md_json_t wrap;
+    void *element;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    if (!j || !json_is_array(j)) {
+        return APR_ENOENT;
+    }
+        
+    wrap.p = a->pool;
+    json_array_foreach(j, index, val) {
+        wrap.j = val;
+        if (APR_SUCCESS == (rv = cb(&element, &wrap, wrap.p, baton))) {
+            if (element) {
+                APR_ARRAY_PUSH(a, void*) = element;
+            }
+        }
+        else if (APR_ENOENT == rv) {
+            rv = APR_SUCCESS;
+        }
+        else {
+            break;
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_json_seta(apr_array_header_t *a, md_json_to_cb *cb, void *baton, 
+                          md_json_t *json, ...)
+{
+    json_t *j, *nj;
+    md_json_t wrap;
+    apr_status_t rv = APR_SUCCESS;
+    va_list ap;
+    int i;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    if (!j || !json_is_array(j)) {
+        const char *key;
+        
+        va_start(ap, json);
+        j = jselect_parent(&key, 1, json, ap);
+        va_end(ap);
+        
+        if (!key || !j || !json_is_object(j)) {
+            return APR_EINVAL;
+        }
+        nj = json_array();
+        json_object_set_new(j, key, nj);
+        j = nj; 
+    }
+    
+    json_array_clear(j);
+    wrap.p = json->p;
+    for (i = 0; i < a->nelts; ++i) {
+        if (!cb) {
+            return APR_EINVAL;
+        }    
+        wrap.j = json_string("");
+        if (APR_SUCCESS == (rv = cb(APR_ARRAY_IDX(a, i, void*), &wrap, json->p, baton))) {
+            json_array_append_new(j, wrap.j);
+        }
+    }
+    return rv;
+}
+
+int md_json_itera(md_json_itera_cb *cb, void *baton, md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    size_t index;
+    json_t *val;
+    md_json_t wrap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    if (!j || !json_is_array(j)) {
+        return 0;
+    }
+        
+    wrap.p = json->p;
+    json_array_foreach(j, index, val) {
+        wrap.j = val;
+        if (!cb(baton, index, &wrap)) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+int md_json_iterkey(md_json_iterkey_cb *cb, void *baton, md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    const char *key;
+    json_t *val;
+    md_json_t wrap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    if (!j || !json_is_object(j)) {
+        return 0;
+    }
+        
+    wrap.p = json->p;
+    json_object_foreach(j, key, val) {
+        wrap.j = val;
+        if (!cb(baton, key, &wrap)) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+/**************************************************************************************************/
+/* array strings */
+
+apr_status_t md_json_getsa(apr_array_header_t *a, const md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    if (j && json_is_array(j)) {
+        size_t index;
+        json_t *val;
+        
+        json_array_foreach(j, index, val) {
+            if (json_is_string(val)) {
+                APR_ARRAY_PUSH(a, const char *) = json_string_value(val);
+            }
+        }
+        return APR_SUCCESS;
+    }
+    return APR_ENOENT;
+}
+
+apr_status_t md_json_dupsa(apr_array_header_t *a, apr_pool_t *p, md_json_t *json, ...)
+{
+    json_t *j;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+
+    if (j && json_is_array(j)) {
+        size_t index;
+        json_t *val;
+        
+        apr_array_clear(a);
+        json_array_foreach(j, index, val) {
+            if (json_is_string(val)) {
+                APR_ARRAY_PUSH(a, const char *) = apr_pstrdup(p, json_string_value(val));
+            }
+        }
+        return APR_SUCCESS;
+    }
+    return APR_ENOENT;
+}
+
+apr_status_t md_json_setsa(apr_array_header_t *a, md_json_t *json, ...)
+{
+    json_t *nj, *j;
+    va_list ap;
+    int i;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    if (!j || !json_is_array(j)) {
+        const char *key;
+        
+        va_start(ap, json);
+        j = jselect_parent(&key, 1, json, ap);
+        va_end(ap);
+        
+        if (!key || !j || !json_is_object(j)) {
+            return APR_EINVAL;
+        }
+        nj = json_array();
+        json_object_set_new(j, key, nj);
+        j = nj; 
+    }
+    
+    json_array_clear(j);
+    for (i = 0; i < a->nelts; ++i) {
+        json_array_append_new(j, json_string(APR_ARRAY_IDX(a, i, const char*)));
+    }
+    return APR_SUCCESS;
+}
+
+/**************************************************************************************************/
+/* formatting, parsing */
+
+typedef struct {
+    const md_json_t *json;
+    md_json_fmt_t fmt;
+    const char *fname;
+    apr_file_t *f;
+} j_write_ctx;
+
+/* Convert from md_json_fmt_t to the Jansson json_dumpX flags. */
+static size_t fmt_to_flags(md_json_fmt_t fmt)
+{
+    /* NOTE: JSON_PRESERVE_ORDER is off by default before Jansson 2.8. It
+     * doesn't have any semantic effect on the protocol, but it does let the
+     * md_json_writeX unit tests run deterministically. */
+    return JSON_PRESERVE_ORDER |
+           ((fmt == MD_JSON_FMT_COMPACT) ? JSON_COMPACT : JSON_INDENT(2)); 
+}
+
+static int dump_cb(const char *buffer, size_t len, void *baton)
+{
+    apr_bucket_brigade *bb = baton;
+    apr_status_t rv;
+    
+    rv = apr_brigade_write(bb, NULL, NULL, buffer, len);
+    return (rv == APR_SUCCESS)? 0 : -1;
+}
+
+apr_status_t md_json_writeb(const md_json_t *json, md_json_fmt_t fmt, apr_bucket_brigade *bb)
+{
+    int rv = json_dump_callback(json->j, dump_cb, bb, fmt_to_flags(fmt));
+    return rv? APR_EGENERAL : APR_SUCCESS;
+}
+
+static int chunk_cb(const char *buffer, size_t len, void *baton)
+{
+    apr_array_header_t *chunks = baton;
+    char *chunk;
+    
+    if (len > 0) {
+        chunk = apr_palloc(chunks->pool, len+1);
+        memcpy(chunk, buffer, len);
+        chunk[len] = '\0';
+        APR_ARRAY_PUSH(chunks, const char*) = chunk;
+    }
+    return 0;
+}
+
+const char *md_json_writep(const md_json_t *json, apr_pool_t *p, md_json_fmt_t fmt)
+{
+    apr_array_header_t *chunks;
+    int rv;
+
+    chunks = apr_array_make(p, 10, sizeof(char *));
+    rv = json_dump_callback(json->j, chunk_cb, chunks, fmt_to_flags(fmt));
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p,
+                      "md_json_writep failed to dump JSON");
+        return NULL;
+    }
+
+    switch (chunks->nelts) {
+        case 0:
+            return "";
+        case 1:
+            return APR_ARRAY_IDX(chunks, 0, const char*);
+        default:
+            return apr_array_pstrcat(p, chunks, 0);
+    }
+}
+
+apr_status_t md_json_writef(const md_json_t *json, apr_pool_t *p, md_json_fmt_t fmt, apr_file_t *f)
+{
+    apr_status_t rv;
+    const char *s;
+    
+    if ((s = md_json_writep(json, p, fmt))) {
+        rv = apr_file_write_full(f, s, strlen(s), NULL);
+        if (APR_SUCCESS != rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, json->p, "md_json_writef: error writing file");
+        }
+    }
+    else {
+        rv = APR_EINVAL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, json->p, 
+                      "md_json_writef: error dumping json (%s)", md_json_dump_state(json, p));
+    }
+    return rv;
+}
+
+apr_status_t md_json_fcreatex(const md_json_t *json, apr_pool_t *p, md_json_fmt_t fmt, 
+                              const char *fpath, apr_fileperms_t perms)
+{
+    apr_status_t rv;
+    apr_file_t *f;
+    
+    rv = md_util_fcreatex(&f, fpath, perms, p);
+    if (APR_SUCCESS == rv) {
+        rv = md_json_writef(json, p, fmt, f);
+        apr_file_close(f);
+    }
+    return rv;
+}
+
+static apr_status_t write_json(void *baton, apr_file_t *f, apr_pool_t *p)
+{
+    j_write_ctx *ctx = baton;
+    apr_status_t rv = md_json_writef(ctx->json, p, ctx->fmt, f);
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "freplace json in %s", ctx->fname);
+    }
+    return rv;
+}
+
+apr_status_t md_json_freplace(const md_json_t *json, apr_pool_t *p, md_json_fmt_t fmt, 
+                              const char *fpath, apr_fileperms_t perms)
+{
+    j_write_ctx ctx;
+    ctx.json = json;
+    ctx.fmt = fmt;
+    ctx.fname = fpath;
+    return md_util_freplace(fpath, perms, p, write_json, &ctx);
+}
+
+apr_status_t md_json_readd(md_json_t **pjson, apr_pool_t *pool, const char *data, size_t data_len)
+{
+    json_error_t error;
+    json_t *j;
+    
+    j = json_loadb(data, data_len, 0, &error);
+    if (!j) {
+        return APR_EINVAL;
+    }
+    *pjson = json_create(pool, j);
+    return APR_SUCCESS;
+}
+
+static size_t load_cb(void *data, size_t max_len, void *baton)
+{
+    apr_bucket_brigade *body = baton;
+    size_t blen, read_len = 0;
+    const char *bdata;
+    char *dest = data;
+    apr_bucket *b;
+    apr_status_t rv;
+    
+    while (body && !APR_BRIGADE_EMPTY(body) && max_len > 0) {
+        b = APR_BRIGADE_FIRST(body);
+        if (APR_BUCKET_IS_METADATA(b)) {
+            if (APR_BUCKET_IS_EOS(b)) {
+                body = NULL;
+            }
+        }
+        else {
+            rv = apr_bucket_read(b, &bdata, &blen, APR_BLOCK_READ);
+            if (rv == APR_SUCCESS) {
+                if (blen > max_len) {
+                    apr_bucket_split(b, max_len);
+                    blen = max_len;
+                }
+                memcpy(dest, bdata, blen);
+                read_len += blen;
+                max_len -= blen;
+                dest += blen;
+            }
+            else {
+                body = NULL;
+                if (!APR_STATUS_IS_EOF(rv)) {
+                    /* everything beside EOF is an error */
+                    read_len = (size_t)-1;
+                }
+            }
+        }
+        APR_BUCKET_REMOVE(b);
+        apr_bucket_delete(b);
+    }
+    
+    return read_len;
+}
+
+apr_status_t md_json_readb(md_json_t **pjson, apr_pool_t *pool, apr_bucket_brigade *bb)
+{
+    json_error_t error;
+    json_t *j;
+    
+    j = json_load_callback(load_cb, bb, 0, &error);
+    if (j) {
+        *pjson = json_create(pool, j);
+    } else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, pool,
+                      "failed to load JSON file: %s (line %d:%d)",
+                      error.text, error.line, error.column);
+    }
+    return (j && *pjson) ? APR_SUCCESS : APR_EINVAL;
+}
+
+static size_t load_file_cb(void *data, size_t max_len, void *baton)
+{
+    apr_file_t *f = baton;
+    apr_size_t len = max_len;
+    apr_status_t rv;
+    
+    rv = apr_file_read(f, data, &len);
+    if (APR_SUCCESS == rv) {
+        return len;
+    }
+    else if (APR_EOF == rv) {
+        return 0;
+    }
+    return (size_t)-1;
+}
+
+apr_status_t md_json_readf(md_json_t **pjson, apr_pool_t *p, const char *fpath)
+{
+    apr_file_t *f;
+    json_t *j;
+    apr_status_t rv;
+    json_error_t error;
+    
+    rv = apr_file_open(&f, fpath, APR_FOPEN_READ, 0, p);
+    if (rv != APR_SUCCESS) {
+        return rv;
+    }
+
+    j = json_load_callback(load_file_cb, f, 0, &error);
+    if (j) {
+        *pjson = json_create(p, j);
+    }
+    else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p,
+                      "failed to load JSON file %s: %s (line %d:%d)",
+                      fpath, error.text, error.line, error.column);
+    }
+
+    apr_file_close(f);
+    return (j && *pjson) ? APR_SUCCESS : APR_EINVAL;
+}
+
+/**************************************************************************************************/
+/* http get */
+
+apr_status_t md_json_read_http(md_json_t **pjson, apr_pool_t *pool, const md_http_response_t *res)
+{
+    apr_status_t rv = APR_ENOENT;
+    const char *ctype, *p;
+
+    *pjson = NULL;
+    if (!res->body) goto cleanup;
+    ctype = md_util_parse_ct(res->req->pool, apr_table_get(res->headers, "content-type"));
+    if (!ctype) goto cleanup;
+    p = ctype + strlen(ctype) +1;
+    if (!strcmp(p - sizeof("/json"), "/json")
+        || !strcmp(p - sizeof("+json"), "+json")) {
+        rv = md_json_readb(pjson, pool, res->body);
+    }
+cleanup:
+    return rv;
+}
+
+typedef struct {
+    apr_status_t rv;
+    apr_pool_t *pool;
+    md_json_t *json;
+} resp_data;
+
+static apr_status_t json_resp_cb(const md_http_response_t *res, void *data)
+{
+    resp_data *resp = data;
+    return md_json_read_http(&resp->json, resp->pool, res);
+}
+
+apr_status_t md_json_http_get(md_json_t **pjson, apr_pool_t *pool,
+                              struct md_http_t *http, const char *url)
+{
+    apr_status_t rv;
+    resp_data resp;
+    
+    memset(&resp, 0, sizeof(resp));
+    resp.pool = pool;
+    
+    rv = md_http_GET_perform(http, url, NULL, json_resp_cb, &resp);
+    
+    if (rv == APR_SUCCESS) {
+        *pjson = resp.json;
+        return resp.rv;
+    }
+    *pjson = NULL;
+    return rv;
+}
+
+
+apr_status_t md_json_copy_to(md_json_t *dest, const md_json_t *src, ...)
+{
+    json_t *j;
+    va_list ap;
+    apr_status_t rv = APR_SUCCESS;
+    
+    va_start(ap, src);
+    j = jselect(src, ap);
+    va_end(ap);
+
+    if (j) {
+        va_start(ap, src);
+        rv = jselect_set(j, dest, ap);
+        va_end(ap);
+    }
+    return rv;
+}
+
+const char *md_json_dump_state(const md_json_t *json, apr_pool_t *p)
+{
+    if (!json) return "NULL";
+    return apr_psprintf(p, "%s, refc=%ld", md_json_type_name(json), (long)json->j->refcount);
+}
+
+apr_status_t md_json_set_timeperiod(const md_timeperiod_t *tp, md_json_t *json, ...)
+{
+    char ts[APR_RFC822_DATE_LEN];
+    json_t *jn, *j;
+    va_list ap;
+    const char *key;
+    apr_status_t rv;
+    
+    if (tp && tp->start && tp->end) {
+        jn = json_object();
+        apr_rfc822_date(ts, tp->start);
+        json_object_set_new(jn, "from", json_string(ts));
+        apr_rfc822_date(ts, tp->end);
+        json_object_set_new(jn, "until", json_string(ts));
+        
+        va_start(ap, json);
+        rv = jselect_set_new(jn, json, ap);
+        va_end(ap);
+        return rv;
+    }
+    else {
+        va_start(ap, json);
+        j = jselect_parent(&key, 0, json, ap);
+        va_end(ap);
+        
+        if (key && j && json_is_object(j)) {
+            json_object_del(j, key);
+        }
+        return APR_SUCCESS;
+    }
+}
+
+apr_status_t md_json_get_timeperiod(md_timeperiod_t *tp, md_json_t *json, ...)
+{
+    json_t *j, *jts;
+    va_list ap;
+    
+    va_start(ap, json);
+    j = jselect(json, ap);
+    va_end(ap);
+    
+    memset(tp, 0, sizeof(*tp));
+    if (!j) goto not_found;
+    jts = json_object_get(j, "from");
+    if (!jts || !json_is_string(jts)) goto not_found;
+    tp->start = apr_date_parse_rfc(json_string_value(jts)); 
+    jts = json_object_get(j, "until");
+    if (!jts || !json_is_string(jts)) goto not_found;
+    tp->end = apr_date_parse_rfc(json_string_value(jts)); 
+    return APR_SUCCESS;
+not_found:
+    return APR_ENOENT;
+}
diff --git a/modules/md/md_json.h b/modules/md/md_json.h
new file mode 100644
index 0000000..50b8828
--- /dev/null
+++ b/modules/md/md_json.h
@@ -0,0 +1,157 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_json_h
+#define mod_md_md_json_h
+
+#include <apr_file_io.h>
+
+struct apr_bucket_brigade;
+struct apr_file_t;
+
+struct md_http_t;
+struct md_http_response_t;
+struct md_timeperiod_t;
+
+typedef struct md_json_t md_json_t;
+
+typedef enum {
+    MD_JSON_TYPE_OBJECT,
+    MD_JSON_TYPE_ARRAY,
+    MD_JSON_TYPE_STRING,
+    MD_JSON_TYPE_REAL,
+    MD_JSON_TYPE_INT,
+    MD_JSON_TYPE_BOOL,
+    MD_JSON_TYPE_NULL,
+} md_json_type_t;
+
+
+typedef enum {
+    MD_JSON_FMT_COMPACT,
+    MD_JSON_FMT_INDENT,
+} md_json_fmt_t;
+
+md_json_t *md_json_create(apr_pool_t *pool);
+void md_json_destroy(md_json_t *json);
+
+md_json_t *md_json_copy(apr_pool_t *pool, const md_json_t *json);
+md_json_t *md_json_clone(apr_pool_t *pool, const md_json_t *json);
+
+
+int md_json_has_key(const md_json_t *json, ...);
+int md_json_is(const md_json_type_t type, md_json_t *json, ...);
+
+/* boolean manipulation */
+int md_json_getb(const md_json_t *json, ...);
+apr_status_t md_json_setb(int value, md_json_t *json, ...);
+
+/* number manipulation */
+double md_json_getn(const md_json_t *json, ...);
+apr_status_t md_json_setn(double value, md_json_t *json, ...);
+
+/* long manipulation */
+long md_json_getl(const md_json_t *json, ...);
+apr_status_t md_json_setl(long value, md_json_t *json, ...);
+
+/* string manipulation */
+md_json_t *md_json_create_s(apr_pool_t *pool, const char *s);
+const char *md_json_gets(const md_json_t *json, ...);
+const char *md_json_dups(apr_pool_t *p, const md_json_t *json, ...);
+apr_status_t md_json_sets(const char *s, md_json_t *json, ...);
+
+/* timestamp manipulation */
+apr_time_t md_json_get_time(const md_json_t *json, ...);
+apr_status_t md_json_set_time(apr_time_t value, md_json_t *json, ...);
+
+/* json manipulation */
+md_json_t *md_json_getj(md_json_t *json, ...);
+md_json_t *md_json_dupj(apr_pool_t *p, const md_json_t *json, ...);
+const md_json_t *md_json_getcj(const md_json_t *json, ...);
+apr_status_t md_json_setj(const md_json_t *value, md_json_t *json, ...);
+apr_status_t md_json_addj(const md_json_t *value, md_json_t *json, ...);
+apr_status_t md_json_insertj(md_json_t *value, size_t index, md_json_t *json, ...);
+
+/* Array/Object manipulation */
+apr_status_t md_json_clr(md_json_t *json, ...);
+apr_status_t md_json_del(md_json_t *json, ...);
+
+/* Remove all array elements beyond max_elements */ 
+apr_size_t md_json_limita(size_t max_elements, md_json_t *json, ...);
+
+/* conversion function from and to json */
+typedef apr_status_t md_json_to_cb(void *value, md_json_t *json, apr_pool_t *p, void *baton);
+typedef apr_status_t md_json_from_cb(void **pvalue, md_json_t *json, apr_pool_t *p, void *baton);
+
+/* identity pass through from json to json */
+apr_status_t md_json_pass_to(void *value, md_json_t *json, apr_pool_t *p, void *baton);
+apr_status_t md_json_pass_from(void **pvalue, md_json_t *json, apr_pool_t *p, void *baton);
+
+/* conversions from json to json in specified pool */
+apr_status_t md_json_clone_to(void *value, md_json_t *json, apr_pool_t *p, void *baton);
+apr_status_t md_json_clone_from(void **pvalue, const md_json_t *json, apr_pool_t *p, void *baton);
+
+/* Manipulating/Iteration on generic Arrays */
+apr_status_t md_json_geta(apr_array_header_t *a, md_json_from_cb *cb, 
+                          void *baton, const md_json_t *json, ...);
+apr_status_t md_json_seta(apr_array_header_t *a, md_json_to_cb *cb, 
+                          void *baton, md_json_t *json, ...);
+
+/* Called on each array element, aborts iteration when returning 0 */
+typedef int md_json_itera_cb(void *baton, size_t index, md_json_t *json);
+int md_json_itera(md_json_itera_cb *cb, void *baton, md_json_t *json, ...);
+
+/* Called on each object key, aborts iteration when returning 0 */
+typedef int md_json_iterkey_cb(void *baton, const char* key, md_json_t *json);
+int md_json_iterkey(md_json_iterkey_cb *cb, void *baton, md_json_t *json, ...);
+
+/* Manipulating Object String values */
+apr_status_t md_json_gets_dict(apr_table_t *dict, const md_json_t *json, ...);
+apr_status_t md_json_sets_dict(apr_table_t *dict, md_json_t *json, ...);
+
+/* Manipulating String Arrays */
+apr_status_t md_json_getsa(apr_array_header_t *a, const md_json_t *json, ...);
+apr_status_t md_json_dupsa(apr_array_header_t *a, apr_pool_t *p, md_json_t *json, ...);
+apr_status_t md_json_setsa(apr_array_header_t *a, md_json_t *json, ...);
+
+/* serialization & parsing */
+apr_status_t md_json_writeb(const md_json_t *json, md_json_fmt_t fmt, struct apr_bucket_brigade *bb);
+const char *md_json_writep(const md_json_t *json, apr_pool_t *p, md_json_fmt_t fmt);
+apr_status_t md_json_writef(const md_json_t *json, apr_pool_t *p, 
+                            md_json_fmt_t fmt, struct apr_file_t *f);
+apr_status_t md_json_fcreatex(const md_json_t *json, apr_pool_t *p, md_json_fmt_t fmt, 
+                              const char *fpath, apr_fileperms_t perms);
+apr_status_t md_json_freplace(const md_json_t *json, apr_pool_t *p, md_json_fmt_t fmt, 
+                              const char *fpath, apr_fileperms_t perms);
+
+apr_status_t md_json_readb(md_json_t **pjson, apr_pool_t *pool, struct apr_bucket_brigade *bb);
+apr_status_t md_json_readd(md_json_t **pjson, apr_pool_t *pool, const char *data, size_t data_len);
+apr_status_t md_json_readf(md_json_t **pjson, apr_pool_t *pool, const char *fpath);
+
+
+/* http retrieval */
+apr_status_t md_json_http_get(md_json_t **pjson, apr_pool_t *pool,
+                              struct md_http_t *http, const char *url);
+apr_status_t md_json_read_http(md_json_t **pjson, apr_pool_t *pool, 
+                               const struct md_http_response_t *res);
+
+apr_status_t md_json_copy_to(md_json_t *dest, const md_json_t *src, ...);
+
+const char *md_json_dump_state(const md_json_t *json, apr_pool_t *p);
+
+apr_status_t md_json_set_timeperiod(const struct md_timeperiod_t *tp, md_json_t *json, ...);
+apr_status_t md_json_get_timeperiod(struct md_timeperiod_t *tp, md_json_t *json, ...);
+
+#endif /* md_json_h */
diff --git a/modules/md/md_jws.c b/modules/md/md_jws.c
new file mode 100644
index 0000000..c0e8c1b
--- /dev/null
+++ b/modules/md/md_jws.c
@@ -0,0 +1,148 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_tables.h>
+#include <apr_buckets.h>
+
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_jws.h"
+#include "md_log.h"
+#include "md_util.h"
+
+apr_status_t md_jws_get_jwk(md_json_t **pjwk, apr_pool_t *p, struct md_pkey_t *pkey)
+{
+    md_json_t *jwk;
+
+    if (!pkey) return APR_EINVAL;
+
+    jwk = md_json_create(p);
+    md_json_sets(md_pkey_get_rsa_e64(pkey, p), jwk, "e", NULL);
+    md_json_sets("RSA", jwk, "kty", NULL);
+    md_json_sets(md_pkey_get_rsa_n64(pkey, p), jwk, "n", NULL);
+    *pjwk = jwk;
+    return APR_SUCCESS;
+}
+
+apr_status_t md_jws_sign(md_json_t **pmsg, apr_pool_t *p,
+                         md_data_t *payload, md_json_t *prot_fields,
+                         struct md_pkey_t *pkey, const char *key_id)
+{
+    md_json_t *msg, *jprotected, *jwk;
+    const char *prot64, *pay64, *sign64, *sign, *prot;
+    md_data_t data;
+    apr_status_t rv;
+
+    msg = md_json_create(p);
+    jprotected = md_json_clone(p, prot_fields);
+    md_json_sets("RS256", jprotected, "alg", NULL);
+    if (key_id) {
+        md_json_sets(key_id, jprotected, "kid", NULL);
+    }
+    else {
+        rv = md_jws_get_jwk(&jwk, p, pkey);
+        if (APR_SUCCESS != rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, p, "get jwk");
+            goto cleanup;
+        }
+        md_json_setj(jwk, jprotected, "jwk", NULL);
+    }
+
+    prot = md_json_writep(jprotected, p, MD_JSON_FMT_COMPACT);
+    if (!prot) {
+        rv = APR_EINVAL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, p, "serialize protected");
+        goto cleanup;
+    }
+
+    md_data_init(&data, prot, strlen(prot));
+    prot64 = md_util_base64url_encode(&data, p);
+    md_json_sets(prot64, msg, "protected", NULL);
+
+    pay64 = md_util_base64url_encode(payload, p);
+    md_json_sets(pay64, msg, "payload", NULL);
+    sign = apr_psprintf(p, "%s.%s", prot64, pay64);
+
+    rv = md_crypt_sign64(&sign64, pkey, p, sign, strlen(sign));
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, p, "jwk signed message");
+        goto cleanup;
+    }
+    md_json_sets(sign64, msg, "signature", NULL);
+
+cleanup:
+    *pmsg = (APR_SUCCESS == rv)? msg : NULL;
+    return rv;
+}
+
+apr_status_t md_jws_pkey_thumb(const char **pthumb, apr_pool_t *p, struct md_pkey_t *pkey)
+{
+    const char *e64, *n64, *s;
+    md_data_t data;
+    apr_status_t rv;
+    
+    e64 = md_pkey_get_rsa_e64(pkey, p);
+    n64 = md_pkey_get_rsa_n64(pkey, p);
+    if (!e64 || !n64) {
+        return APR_EINVAL;
+    }
+
+    /* whitespace and order is relevant, since we hand out a digest of this */
+    s = apr_psprintf(p, "{\"e\":\"%s\",\"kty\":\"RSA\",\"n\":\"%s\"}", e64, n64);
+    md_data_init_str(&data, s);
+    rv = md_crypt_sha256_digest64(pthumb, p, &data);
+    return rv;
+}
+
+apr_status_t md_jws_hmac(md_json_t **pmsg, apr_pool_t *p,
+                         md_data_t *payload, md_json_t *prot_fields,
+                         const md_data_t *hmac_key)
+{
+    md_json_t *msg, *jprotected;
+    const char *prot64, *pay64, *mac64, *sign, *prot;
+    md_data_t data;
+    apr_status_t rv;
+
+    msg = md_json_create(p);
+    jprotected = md_json_clone(p, prot_fields);
+    md_json_sets("HS256", jprotected, "alg", NULL);
+    prot = md_json_writep(jprotected, p, MD_JSON_FMT_COMPACT);
+    if (!prot) {
+        rv = APR_EINVAL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, p, "serialize protected");
+        goto cleanup;
+    }
+
+    md_data_init(&data, prot, strlen(prot));
+    prot64 = md_util_base64url_encode(&data, p);
+    md_json_sets(prot64, msg, "protected", NULL);
+
+    pay64 = md_util_base64url_encode(payload, p);
+    md_json_sets(pay64, msg, "payload", NULL);
+    sign = apr_psprintf(p, "%s.%s", prot64, pay64);
+
+    rv = md_crypt_hmac64(&mac64, hmac_key, p, sign, strlen(sign));
+    if (APR_SUCCESS != rv) {
+        goto cleanup;
+    }
+    md_json_sets(mac64, msg, "signature", NULL);
+
+cleanup:
+    *pmsg = (APR_SUCCESS == rv)? msg : NULL;
+    return rv;
+}
diff --git a/modules/md/md_jws.h b/modules/md/md_jws.h
new file mode 100644
index 0000000..466f2df
--- /dev/null
+++ b/modules/md/md_jws.h
@@ -0,0 +1,52 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_jws_h
+#define mod_md_md_jws_h
+
+struct apr_table_t;
+struct md_json_t;
+struct md_pkey_t;
+struct md_data_t;
+
+/**
+ * Get the JSON value of the 'jwk' field for the given key.
+ */
+apr_status_t md_jws_get_jwk(md_json_t **pjwk, apr_pool_t *p, struct md_pkey_t *pkey);
+
+/**
+ * Get the JWS key signed JSON message with given payload and protected fields, signed
+ * using the given key and optional key_id.
+ */
+apr_status_t md_jws_sign(md_json_t **pmsg, apr_pool_t *p,
+                         struct md_data_t *payload, md_json_t *prot_fields,
+                         struct md_pkey_t *pkey, const char *key_id);
+/**
+ * Get the 'Thumbprint' as defined in RFC8555 for the given key in
+ * base64 encoding.
+ */
+apr_status_t md_jws_pkey_thumb(const char **pthumb64, apr_pool_t *p, struct md_pkey_t *pkey);
+
+/**
+ * Get the JWS HS256 signed message for given payload and protected fields,
+ * using the base64 encoded MAC key.
+ */
+apr_status_t md_jws_hmac(md_json_t **pmsg, apr_pool_t *p,
+                         struct md_data_t *payload, md_json_t *prot_fields,
+                         const struct md_data_t *hmac_key);
+
+
+#endif /* md_jws_h */
diff --git a/modules/md/md_log.c b/modules/md/md_log.c
new file mode 100644
index 0000000..d236e0f
--- /dev/null
+++ b/modules/md/md_log.c
@@ -0,0 +1,78 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_buckets.h>
+
+#include "md_log.h"
+
+#define LOG_BUFFER_LEN  1024
+
+static const char *level_names[] = {
+    "emergency",
+    "alert",
+    "crit",
+    "err",
+    "warning",
+    "notice",
+    "info",
+    "debug",
+    "trace1",
+    "trace2",
+    "trace3",
+    "trace4",
+    "trace5",
+    "trace6",
+    "trace7",
+    "trace8",
+};
+
+const char *md_log_level_name(md_log_level_t level)
+{
+    return level_names[level];
+}
+
+static md_log_print_cb *log_printv;
+static md_log_level_cb *log_level;
+static void *log_baton;
+
+void md_log_set(md_log_level_cb *level_cb, md_log_print_cb *print_cb, void *baton)
+{
+    log_printv = print_cb;
+    log_level = level_cb;
+    log_baton = baton;
+}
+
+int md_log_is_level(apr_pool_t *p, md_log_level_t level)
+{
+    if (!log_level) {
+        return 0;
+    }
+    return log_level(log_baton, p, level);
+}
+
+void md_log_perror(const char *file, int line, md_log_level_t level, 
+                   apr_status_t rv, apr_pool_t *p, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    if (log_printv) {
+        log_printv(file, line, level, rv, log_baton, p, fmt, ap);
+    }
+    va_end(ap);
+}
diff --git a/modules/md/md_log.h b/modules/md/md_log.h
new file mode 100644
index 0000000..19e688f
--- /dev/null
+++ b/modules/md/md_log.h
@@ -0,0 +1,60 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_log_h
+#define mod_md_md_log_h
+
+typedef enum {
+    MD_LOG_EMERG,
+    MD_LOG_ALERT,
+    MD_LOG_CRIT,
+    MD_LOG_ERR, 
+    MD_LOG_WARNING, 
+    MD_LOG_NOTICE, 
+    MD_LOG_INFO, 
+    MD_LOG_DEBUG, 
+    MD_LOG_TRACE1, 
+    MD_LOG_TRACE2, 
+    MD_LOG_TRACE3, 
+    MD_LOG_TRACE4, 
+    MD_LOG_TRACE5, 
+    MD_LOG_TRACE6, 
+    MD_LOG_TRACE7, 
+    MD_LOG_TRACE8, 
+} md_log_level_t;
+
+#define MD_LOG_MARK     __FILE__,__LINE__
+
+#ifndef APLOGNO
+#define APLOGNO(n)              "AH" #n ": "
+#endif
+
+const char *md_log_level_name(md_log_level_t level);
+
+int md_log_is_level(apr_pool_t *p, md_log_level_t level);
+
+void md_log_perror(const char *file, int line, md_log_level_t level, 
+                   apr_status_t rv, apr_pool_t *p, const char *fmt, ...)
+                                __attribute__((format(printf,6,7)));
+
+typedef int md_log_level_cb(void *baton, apr_pool_t *p, md_log_level_t level);
+
+typedef void md_log_print_cb(const char *file, int line, md_log_level_t level, 
+                apr_status_t rv, void *baton, apr_pool_t *p, const char *fmt, va_list ap);
+
+void md_log_set(md_log_level_cb *level_cb, md_log_print_cb *print_cb, void *baton);
+
+#endif /* md_log_h */
diff --git a/modules/md/md_ocsp.c b/modules/md/md_ocsp.c
new file mode 100644
index 0000000..8cbf05b
--- /dev/null
+++ b/modules/md/md_ocsp.c
@@ -0,0 +1,1063 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_buckets.h>
+#include <apr_hash.h>
+#include <apr_time.h>
+#include <apr_date.h>
+#include <apr_strings.h>
+#include <apr_thread_mutex.h>
+
+#include <openssl/err.h>
+#include <openssl/evp.h>
+#include <openssl/ocsp.h>
+#include <openssl/pem.h>
+#include <openssl/x509v3.h>
+
+#if defined(LIBRESSL_VERSION_NUMBER)
+/* Missing from LibreSSL */
+#define MD_USE_OPENSSL_PRE_1_1_API (LIBRESSL_VERSION_NUMBER < 0x2070000f)
+#else /* defined(LIBRESSL_VERSION_NUMBER) */
+#define MD_USE_OPENSSL_PRE_1_1_API (OPENSSL_VERSION_NUMBER < 0x10100000L)
+#endif
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_event.h"
+#include "md_json.h"
+#include "md_log.h"
+#include "md_http.h"
+#include "md_json.h"
+#include "md_result.h"
+#include "md_status.h"
+#include "md_store.h"
+#include "md_util.h"
+#include "md_ocsp.h"
+
+#define MD_OCSP_ID_LENGTH   SHA_DIGEST_LENGTH
+   
+struct md_ocsp_reg_t {
+    apr_pool_t *p;
+    md_store_t *store;
+    const char *user_agent;
+    const char *proxy_url;
+    apr_hash_t *id_by_external_id;
+    apr_hash_t *ostat_by_id;
+    apr_thread_mutex_t *mutex;
+    md_timeslice_t renew_window;
+    md_job_notify_cb *notify;
+    void *notify_ctx;
+    apr_time_t min_delay;
+};
+
+typedef struct md_ocsp_status_t md_ocsp_status_t; 
+struct md_ocsp_status_t {
+    md_data_t id;
+    const char *hexid;
+    const char *hex_sha256;
+    OCSP_CERTID *certid;
+    const char *responder_url;
+    
+    apr_time_t next_run;      /* when the responder shall be asked again */
+    int errors;               /* consecutive failed attempts */
+
+    md_ocsp_cert_stat_t resp_stat;
+    md_data_t resp_der;
+    md_timeperiod_t resp_valid;
+    
+    md_data_t req_der;
+    OCSP_REQUEST *ocsp_req;
+    md_ocsp_reg_t *reg;
+
+    const char *md_name;
+    const char *file_name;
+    
+    apr_time_t resp_mtime;
+    apr_time_t resp_last_check;
+};
+
+typedef struct md_ocsp_id_map_t md_ocsp_id_map_t;
+struct md_ocsp_id_map_t {
+    md_data_t id;
+    md_data_t external_id;
+};
+
+static void md_openssl_free(void *d)
+{
+    OPENSSL_free(d);
+}
+
+const char *md_ocsp_cert_stat_name(md_ocsp_cert_stat_t stat)
+{
+    switch (stat) {
+        case MD_OCSP_CERT_ST_GOOD: return "good";
+        case MD_OCSP_CERT_ST_REVOKED: return "revoked";
+        default: return "unknown";
+    }
+}
+
+md_ocsp_cert_stat_t md_ocsp_cert_stat_value(const char *name)
+{
+    if (name && !strcmp("good", name)) return MD_OCSP_CERT_ST_GOOD;
+    if (name && !strcmp("revoked", name)) return MD_OCSP_CERT_ST_REVOKED;
+    return MD_OCSP_CERT_ST_UNKNOWN;
+}
+
+apr_status_t md_ocsp_init_id(md_data_t *id, apr_pool_t *p, const md_cert_t *cert)
+{
+    unsigned char iddata[SHA_DIGEST_LENGTH];
+    X509 *x = md_cert_get_X509(cert);
+    unsigned int ulen = 0;
+    
+    md_data_null(id);
+    if (X509_digest(x, EVP_sha1(), iddata, &ulen) != 1) {
+        return APR_EGENERAL;
+    }
+    md_data_assign_pcopy(id, (const char*)iddata, ulen, p);
+    return APR_SUCCESS;
+}
+
+static void ostat_req_cleanup(md_ocsp_status_t *ostat)
+{
+    if (ostat->ocsp_req) {
+        OCSP_REQUEST_free(ostat->ocsp_req);
+        ostat->ocsp_req = NULL;
+    }
+    md_data_clear(&ostat->req_der);
+}
+
+static int ostat_cleanup(void *ctx, const void *key, apr_ssize_t klen, const void *val)
+{
+    md_ocsp_reg_t *reg = ctx;
+    md_ocsp_status_t *ostat = (md_ocsp_status_t *)val;
+    
+    (void)reg;
+    (void)key;
+    (void)klen;
+    ostat_req_cleanup(ostat);
+    if (ostat->certid) {
+        OCSP_CERTID_free(ostat->certid);
+        ostat->certid = NULL;
+    }
+    md_data_clear(&ostat->resp_der);
+    return 1;
+}
+
+static int ostat_should_renew(md_ocsp_status_t *ostat) 
+{
+    md_timeperiod_t renewal;
+    
+    renewal = md_timeperiod_slice_before_end(&ostat->resp_valid, &ostat->reg->renew_window);
+    return md_timeperiod_has_started(&renewal, apr_time_now());
+}  
+
+static apr_status_t ostat_set(md_ocsp_status_t *ostat, md_ocsp_cert_stat_t stat,
+                              md_data_t *der, md_timeperiod_t *valid, apr_time_t mtime)
+{
+    apr_status_t rv;
+
+    rv = md_data_assign_copy(&ostat->resp_der, der->data, der->len);
+    if (APR_SUCCESS != rv) goto cleanup;
+
+    ostat->resp_stat = stat;
+    ostat->resp_valid = *valid;
+    ostat->resp_mtime = mtime;
+    
+    ostat->errors = 0;
+    ostat->next_run = md_timeperiod_slice_before_end(
+        &ostat->resp_valid, &ostat->reg->renew_window).start;
+    
+cleanup:
+    return rv;
+}
+
+static apr_status_t ostat_from_json(md_ocsp_cert_stat_t *pstat, 
+                                    md_data_t *resp_der, md_timeperiod_t *resp_valid, 
+                                    md_json_t *json, apr_pool_t *p)
+{
+    const char *s;
+    md_timeperiod_t valid;
+    apr_status_t rv = APR_ENOENT;
+    
+    memset(resp_der, 0, sizeof(*resp_der));
+    memset(resp_valid, 0, sizeof(*resp_valid));
+    s = md_json_dups(p, json, MD_KEY_VALID, MD_KEY_FROM, NULL);
+    if (s && *s) valid.start = apr_date_parse_rfc(s);
+    s = md_json_dups(p, json, MD_KEY_VALID, MD_KEY_UNTIL, NULL);
+    if (s && *s) valid.end = apr_date_parse_rfc(s);
+    s = md_json_dups(p, json, MD_KEY_RESPONSE, NULL);
+    if (!s || !*s) goto cleanup;
+    md_util_base64url_decode(resp_der, s, p);
+    *pstat = md_ocsp_cert_stat_value(md_json_gets(json, MD_KEY_STATUS, NULL));
+    *resp_valid = valid;
+    rv = APR_SUCCESS;
+cleanup:
+    return rv;
+}
+
+static void ostat_to_json(md_json_t *json, md_ocsp_cert_stat_t stat,
+                          const md_data_t *resp_der, const md_timeperiod_t *resp_valid, 
+                          apr_pool_t *p)
+{
+    const char *s = NULL;
+
+    if (resp_der->len > 0) {
+        md_json_sets(md_util_base64url_encode(resp_der, p), json, MD_KEY_RESPONSE, NULL);
+        s = md_ocsp_cert_stat_name(stat);
+        if (s) md_json_sets(s, json, MD_KEY_STATUS, NULL);
+        md_json_set_timeperiod(resp_valid, json, MD_KEY_VALID, NULL);
+    }
+}
+
+static apr_status_t ocsp_status_refresh(md_ocsp_status_t *ostat, apr_pool_t *ptemp)
+{
+    md_store_t *store = ostat->reg->store;
+    md_json_t *jprops;
+    apr_time_t mtime;
+    apr_status_t rv = APR_EAGAIN;
+    md_data_t resp_der;
+    md_timeperiod_t resp_valid;
+    md_ocsp_cert_stat_t resp_stat;
+    /* Check if the store holds a newer response than the one we have */
+    mtime = md_store_get_modified(store, MD_SG_OCSP, ostat->md_name, ostat->file_name, ptemp);
+    if (mtime <= ostat->resp_mtime) goto cleanup;
+    rv = md_store_load_json(store, MD_SG_OCSP, ostat->md_name, ostat->file_name, &jprops, ptemp);
+    if (APR_SUCCESS != rv) goto cleanup;
+    rv = ostat_from_json(&resp_stat, &resp_der, &resp_valid, jprops, ptemp);
+    if (APR_SUCCESS != rv) goto cleanup;
+    rv = ostat_set(ostat, resp_stat, &resp_der, &resp_valid, mtime);
+    if (APR_SUCCESS != rv) goto cleanup;
+cleanup:
+    return rv;
+}
+
+
+static apr_status_t ocsp_status_save(md_ocsp_cert_stat_t stat, const md_data_t *resp_der, 
+                                     const md_timeperiod_t *resp_valid,
+                                     md_ocsp_status_t *ostat, apr_pool_t *ptemp)
+{
+    md_store_t *store = ostat->reg->store;
+    md_json_t *jprops;
+    apr_time_t mtime;
+    apr_status_t rv;
+    
+    jprops = md_json_create(ptemp);
+    ostat_to_json(jprops, stat, resp_der, resp_valid, ptemp);
+    rv = md_store_save_json(store, ptemp, MD_SG_OCSP, ostat->md_name, ostat->file_name, jprops, 0);
+    if (APR_SUCCESS != rv) goto cleanup;
+    mtime = md_store_get_modified(store, MD_SG_OCSP, ostat->md_name, ostat->file_name, ptemp);
+    if (mtime) ostat->resp_mtime = mtime;
+cleanup:
+    return rv;
+}
+
+static apr_status_t ocsp_reg_cleanup(void *data)
+{
+    md_ocsp_reg_t *reg = data;
+    
+    /* free all OpenSSL structures that we hold */
+    apr_hash_do(ostat_cleanup, reg, reg->ostat_by_id);
+    return APR_SUCCESS;
+}
+
+apr_status_t md_ocsp_reg_make(md_ocsp_reg_t **preg, apr_pool_t *p, md_store_t *store, 
+                              const md_timeslice_t *renew_window,
+                              const char *user_agent, const char *proxy_url,
+                              apr_time_t min_delay)
+{
+    md_ocsp_reg_t *reg;
+    apr_status_t rv = APR_SUCCESS;
+    
+    reg = apr_palloc(p, sizeof(*reg));
+    if (!reg) {
+        rv = APR_ENOMEM;
+        goto cleanup;
+    }
+    reg->p = p;
+    reg->store = store;
+    reg->user_agent = user_agent;
+    reg->proxy_url = proxy_url;
+    reg->id_by_external_id = apr_hash_make(p);
+    reg->ostat_by_id = apr_hash_make(p);
+    reg->renew_window = *renew_window;
+    reg->min_delay = min_delay;
+    
+    rv = apr_thread_mutex_create(&reg->mutex, APR_THREAD_MUTEX_NESTED, p);
+    if (APR_SUCCESS != rv) goto cleanup;
+
+    apr_pool_cleanup_register(p, reg, ocsp_reg_cleanup, apr_pool_cleanup_null);
+cleanup:
+    *preg = (APR_SUCCESS == rv)? reg : NULL;
+    return rv;
+}
+
+apr_status_t md_ocsp_prime(md_ocsp_reg_t *reg, const char *ext_id, apr_size_t ext_id_len,
+                           md_cert_t *cert, md_cert_t *issuer, const md_t *md)
+{
+    md_ocsp_status_t *ostat;
+    const char *name;
+    md_data_t id;
+    apr_status_t rv = APR_SUCCESS;
+    
+    /* Called during post_config. no mutex protection needed */
+    name = md? md->name : MD_OTHER;
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, reg->p,
+                  "md[%s]: priming OCSP status", name);
+
+    rv = md_ocsp_init_id(&id, reg->p, cert);
+    if (APR_SUCCESS != rv) goto cleanup;
+
+    ostat = apr_hash_get(reg->ostat_by_id, id.data, (apr_ssize_t)id.len);
+    if (ostat) goto cleanup; /* already seen it, cert is used in >1 server_rec */
+
+    ostat = apr_pcalloc(reg->p, sizeof(*ostat));
+    ostat->id = id;
+    ostat->reg = reg;
+    ostat->md_name = name;
+    md_data_to_hex(&ostat->hexid, 0, reg->p, &ostat->id);
+    ostat->file_name = apr_psprintf(reg->p, "ocsp-%s.json", ostat->hexid);
+    rv = md_cert_to_sha256_fingerprint(&ostat->hex_sha256, cert, reg->p); 
+    if (APR_SUCCESS != rv) goto cleanup;
+
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, reg->p, 
+                  "md[%s]: getting ocsp responder from cert", name);
+    rv = md_cert_get_ocsp_responder_url(&ostat->responder_url, reg->p, cert);
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, reg->p,
+                      "md[%s]: certificate with serial %s has no OCSP responder URL",
+                      name, md_cert_get_serial_number(cert, reg->p));
+        goto cleanup;
+    }
+
+    ostat->certid = OCSP_cert_to_id(NULL, md_cert_get_X509(cert), md_cert_get_X509(issuer));
+    if (!ostat->certid) {
+        rv = APR_EGENERAL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, reg->p, 
+                      "md[%s]: unable to create OCSP certid for certificate with serial %s", 
+                      name, md_cert_get_serial_number(cert, reg->p));
+        goto cleanup;
+    }
+    
+    /* See, if we have something in store */
+    ocsp_status_refresh(ostat, reg->p);
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, reg->p, 
+                  "md[%s]: adding ocsp info (responder=%s)", 
+                  name, ostat->responder_url);
+    apr_hash_set(reg->ostat_by_id, ostat->id.data, (apr_ssize_t)ostat->id.len, ostat);
+    if (ext_id) {
+        md_ocsp_id_map_t *id_map;
+
+        id_map = apr_pcalloc(reg->p, sizeof(*id_map));
+        id_map->id = id;
+        md_data_assign_pcopy(&id_map->external_id, ext_id, ext_id_len, reg->p);
+        /* check for collision/uniqness? */
+        apr_hash_set(reg->id_by_external_id, id_map->external_id.data,
+                     (apr_ssize_t)id_map->external_id.len, id_map);
+    }
+    rv = APR_SUCCESS;
+cleanup:
+    return rv;
+}
+
+apr_status_t md_ocsp_get_status(md_ocsp_copy_der *cb, void *userdata, md_ocsp_reg_t *reg,
+                                const char *ext_id, apr_size_t ext_id_len,
+                                apr_pool_t *p, const md_t *md)
+{
+    md_ocsp_status_t *ostat;
+    const char *name;
+    apr_status_t rv = APR_SUCCESS;
+    md_ocsp_id_map_t *id_map;
+    const char *id;
+    apr_size_t id_len;
+    int locked = 0;
+
+    (void)p;
+    (void)md;
+    name = md? md->name : MD_OTHER;
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, reg->p, 
+                  "md[%s]: OCSP, get_status", name);
+
+    id_map = apr_hash_get(reg->id_by_external_id, ext_id, (apr_ssize_t)ext_id_len);
+    id = id_map? id_map->id.data : ext_id;
+    id_len = id_map? id_map->id.len : ext_id_len;
+    ostat = apr_hash_get(reg->ostat_by_id, id, (apr_ssize_t)id_len);
+    if (!ostat) {
+        rv = APR_ENOENT;
+        goto cleanup;
+    }
+    
+    /* While the ostat instance itself always exists, the response data it holds
+     * may vary over time and we need locked access to make a copy. */
+    apr_thread_mutex_lock(reg->mutex);
+    locked = 1;
+    
+    if (ostat->resp_der.len <= 0) {
+        /* No response known, check store for new response. */
+        ocsp_status_refresh(ostat, p);
+        if (ostat->resp_der.len <= 0) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, reg->p, 
+                          "md[%s]: OCSP, no response available", name);
+            cb(NULL, 0, userdata);
+            goto cleanup;
+        }
+    }
+    /* We have a response */
+    if (ostat_should_renew(ostat)) {
+        /* But it is up for renewal. A watchdog should be busy with
+         * retrieving a new one. In case of outages, this might take
+         * a while, however. Pace the frequency of checks with the
+         * urgency of a new response based on the remaining time. */
+        long secs = (long)apr_time_sec(md_timeperiod_remaining(&ostat->resp_valid, apr_time_now()));
+        apr_time_t waiting_time; 
+        
+        /* every hour, every minute, every second */
+        waiting_time = ((secs >= MD_SECS_PER_DAY)?
+                        apr_time_from_sec(60 * 60) : ((secs >= 60)? 
+                        apr_time_from_sec(60) : apr_time_from_sec(1)));
+        if ((apr_time_now() - ostat->resp_last_check) >= waiting_time) {
+            ostat->resp_last_check = apr_time_now();
+            ocsp_status_refresh(ostat, p);
+        }
+    }
+
+    cb((const unsigned char*)ostat->resp_der.data, ostat->resp_der.len, userdata);
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, reg->p,
+                  "md[%s]: OCSP, provided %ld bytes of response",
+                  name, (long)ostat->resp_der.len);
+cleanup:
+    if (locked) apr_thread_mutex_unlock(reg->mutex);
+    return rv;
+}
+
+static void ocsp_get_meta(md_ocsp_cert_stat_t *pstat, md_timeperiod_t *pvalid, 
+                          md_ocsp_reg_t *reg, md_ocsp_status_t *ostat, apr_pool_t *p)
+{
+    apr_thread_mutex_lock(reg->mutex);
+    if (ostat->resp_der.len <= 0) {
+        /* No response known, check the store if out watchdog retrieved one 
+         * in the meantime. */
+        ocsp_status_refresh(ostat, p);
+    }
+    *pvalid = ostat->resp_valid;
+    *pstat = ostat->resp_stat;
+    apr_thread_mutex_unlock(reg->mutex);
+}
+
+apr_status_t md_ocsp_get_meta(md_ocsp_cert_stat_t *pstat, md_timeperiod_t *pvalid,
+                              md_ocsp_reg_t *reg, const md_cert_t *cert,
+                              apr_pool_t *p, const md_t *md)
+{
+    md_ocsp_status_t *ostat;
+    const char *name;
+    apr_status_t rv;
+    md_timeperiod_t valid;
+    md_ocsp_cert_stat_t stat;
+    md_data_t id;
+    
+    (void)p;
+    (void)md;
+    name = md? md->name : MD_OTHER;
+    memset(&valid, 0, sizeof(valid));
+    stat = MD_OCSP_CERT_ST_UNKNOWN;
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, reg->p, 
+                  "md[%s]: OCSP, get_status", name);
+    
+    rv = md_ocsp_init_id(&id, p, cert);
+    if (APR_SUCCESS != rv) goto cleanup;
+    
+    ostat = apr_hash_get(reg->ostat_by_id, id.data, (apr_ssize_t)id.len);
+    if (!ostat) {
+        rv = APR_ENOENT;
+        goto cleanup;
+    }
+    ocsp_get_meta(&stat, &valid, reg, ostat, p);
+cleanup:
+    *pstat = stat;
+    *pvalid = valid;  
+    return rv;
+}
+
+apr_size_t md_ocsp_count(md_ocsp_reg_t *reg)
+{
+    return apr_hash_count(reg->ostat_by_id);
+}
+
+static const char *certid_as_hex(const OCSP_CERTID *certid, apr_pool_t *p)
+{
+    md_data_t der;
+    const char *hex;
+    
+    memset(&der, 0, sizeof(der));
+    der.len = (apr_size_t)i2d_OCSP_CERTID((OCSP_CERTID*)certid, (unsigned char**)&der.data);
+    der.free_data = md_openssl_free;
+    md_data_to_hex(&hex, 0, p, &der);
+    md_data_clear(&der);
+    return hex;
+}
+
+static const char *certid_summary(const OCSP_CERTID *certid, apr_pool_t *p)
+{
+    const char *serial, *issuer, *key, *s;
+    ASN1_INTEGER *aserial;
+    ASN1_OCTET_STRING *aname_hash, *akey_hash;
+    ASN1_OBJECT *amd_nid;
+    BIGNUM *bn; 
+    md_data_t data;
+    
+    serial = issuer = key = "???";
+    OCSP_id_get0_info(&aname_hash, &amd_nid, &akey_hash, &aserial, (OCSP_CERTID*)certid);
+    if (aname_hash) {
+        data.len = (apr_size_t)aname_hash->length;
+        data.data = (const char*)aname_hash->data;
+        md_data_to_hex(&issuer, 0, p, &data);
+    }
+    if (akey_hash) {
+        data.len = (apr_size_t)akey_hash->length;
+        data.data = (const char*)akey_hash->data;
+        md_data_to_hex(&key, 0, p, &data);
+    }
+    if (aserial) {
+        bn = ASN1_INTEGER_to_BN(aserial, NULL);
+        s = BN_bn2hex(bn);
+        serial = apr_pstrdup(p, s);
+        OPENSSL_free((void*)bn);
+        OPENSSL_free((void*)s);
+    }
+    return apr_psprintf(p, "certid[der=%s, issuer=%s, key=%s, serial=%s]",
+                        certid_as_hex(certid, p), issuer, key, serial);
+}
+
+static const char *certstatus_string(int status)
+{
+    switch (status) {
+        case V_OCSP_CERTSTATUS_GOOD: return "good";
+        case V_OCSP_CERTSTATUS_REVOKED: return "revoked";
+        case V_OCSP_CERTSTATUS_UNKNOWN: return "unknown";
+        default: return "???";
+    }
+
+}
+
+static const char *single_resp_summary(OCSP_SINGLERESP* resp, apr_pool_t *p)
+{
+    const OCSP_CERTID *certid;
+    int status, reason = 0;
+    ASN1_GENERALIZEDTIME *bup = NULL, *bnextup = NULL;
+    md_timeperiod_t valid;
+    
+#if MD_USE_OPENSSL_PRE_1_1_API
+    certid = resp->certId;
+#else
+    certid = OCSP_SINGLERESP_get0_id(resp);
+#endif
+    status = OCSP_single_get0_status(resp, &reason, NULL, &bup, &bnextup);
+    valid.start = bup? md_asn1_generalized_time_get(bup) : apr_time_now();
+    valid.end = md_asn1_generalized_time_get(bnextup);
+
+    return apr_psprintf(p, "ocsp-single-resp[%s, status=%s, reason=%d, valid=%s]",
+                        certid_summary(certid, p),
+                        certstatus_string(status), reason,
+                        md_timeperiod_print(p, &valid));
+}
+
+typedef struct {
+    apr_pool_t *p;
+    md_ocsp_status_t *ostat;
+    md_result_t *result;
+    md_job_t *job;
+} md_ocsp_update_t;
+
+static apr_status_t ostat_on_resp(const md_http_response_t *resp, void *baton)
+{
+    md_ocsp_update_t *update = baton;
+    md_ocsp_status_t *ostat = update->ostat;
+    md_http_request_t *req = resp->req;
+    OCSP_RESPONSE *ocsp_resp = NULL;
+    OCSP_BASICRESP *basic_resp = NULL;
+    OCSP_SINGLERESP *single_resp;
+    apr_status_t rv = APR_SUCCESS;
+    int n, breason = 0, bstatus;
+    ASN1_GENERALIZEDTIME *bup = NULL, *bnextup = NULL;
+    md_data_t der, new_der;
+    md_timeperiod_t valid;
+    md_ocsp_cert_stat_t nstat;
+    
+    der.data = new_der.data = NULL;
+    der.len  = new_der.len = 0;
+
+    md_result_activity_printf(update->result, "status of certid %s, reading response", 
+                              ostat->hexid);
+    if (APR_SUCCESS != (rv = apr_brigade_pflatten(resp->body, (char**)&der.data, 
+                                                  &der.len, req->pool))) {
+        goto cleanup;
+    }
+    if (NULL == (ocsp_resp = d2i_OCSP_RESPONSE(NULL, (const unsigned char**)&der.data, 
+                                               (long)der.len))) {
+        rv = APR_EINVAL;
+
+        md_result_set(update->result, rv,
+                      apr_psprintf(req->pool, "req[%d] response body does not parse as "
+                                   "OCSP response, status=%d, body brigade length=%ld",
+                                   resp->req->id, resp->status, (long)der.len));
+        md_result_log(update->result, MD_LOG_DEBUG);
+        goto cleanup;
+    }
+    /* got a response! but what does it say? */
+    n = OCSP_response_status(ocsp_resp);
+    if (OCSP_RESPONSE_STATUS_SUCCESSFUL != n) {
+        rv = APR_EINVAL;
+        md_result_printf(update->result, rv, "OCSP response status is, unsuccessfully, %d", n);
+        md_result_log(update->result, MD_LOG_DEBUG);
+        goto cleanup;
+    }
+    basic_resp = OCSP_response_get1_basic(ocsp_resp);
+    if (!basic_resp) {
+        rv = APR_EINVAL;
+        md_result_set(update->result, rv, "OCSP response has no basicresponse");
+        md_result_log(update->result, MD_LOG_DEBUG);
+        goto cleanup;
+    }
+    /* The notion of nonce enabled freshness in OCSP responses, e.g. that the response
+     * contains the signed nonce we sent to the responder, does not scale well. Responders
+     * like to return cached response bytes and therefore do not add a nonce to it.
+     * So, in reality, we can only detect a mismatch when present and otherwise have
+     * to accept it. */
+    switch ((n = OCSP_check_nonce(ostat->ocsp_req, basic_resp))) {
+        case 1:
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, req->pool,
+                          "req[%d]: OCSP response nonce does match", req->id);
+            break;
+        case 0:
+            rv = APR_EINVAL;
+            md_result_printf(update->result, rv, "OCSP nonce mismatch in response", n);
+            md_result_log(update->result, MD_LOG_WARNING);
+            goto cleanup;
+            
+        case -1:
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, req->pool,
+                          "req[%d]: OCSP response did not return the nonce", req->id);
+            break;
+        default:
+            break;
+    }
+    
+    if (!OCSP_resp_find_status(basic_resp, ostat->certid, &bstatus,
+                               &breason, NULL, &bup, &bnextup)) {
+        const char *prefix, *slist = "", *sep = "";
+        int i;
+        
+        rv = APR_EINVAL;
+        prefix = apr_psprintf(req->pool, "OCSP response, no matching status reported for  %s",
+                              certid_summary(ostat->certid, req->pool));
+        for (i = 0; i < OCSP_resp_count(basic_resp); ++i) {
+            single_resp = OCSP_resp_get0(basic_resp, i);
+            slist = apr_psprintf(req->pool, "%s%s%s", slist, sep, 
+                                 single_resp_summary(single_resp, req->pool));
+            sep = ", ";
+        }
+        md_result_printf(update->result, rv, "%s, status list [%s]", prefix, slist);
+        md_result_log(update->result, MD_LOG_DEBUG);
+        goto cleanup;
+    }
+    if (V_OCSP_CERTSTATUS_UNKNOWN == bstatus) {
+        rv = APR_ENOENT;
+        md_result_set(update->result, rv, "OCSP basicresponse says cert is unknown");
+        md_result_log(update->result, MD_LOG_DEBUG);
+        goto cleanup;
+    }
+    if (!bnextup) {
+        rv = APR_EINVAL;
+        md_result_set(update->result, rv, "OCSP basicresponse reports not valid dates");
+        md_result_log(update->result, MD_LOG_DEBUG);
+        goto cleanup;
+    }
+    
+    /* Coming here, we have a response for our certid and it is either GOOD
+     * or REVOKED. Both cases we want to remember and use in stapling. */
+    n = i2d_OCSP_RESPONSE(ocsp_resp, (unsigned char**)&new_der.data);
+    if (n <= 0) {
+        rv = APR_EGENERAL;
+        md_result_set(update->result, rv, "error DER encoding OCSP response");
+        md_result_log(update->result, MD_LOG_WARNING);
+        goto cleanup;
+    }
+    new_der.len = (apr_size_t)n;
+    new_der.free_data = md_openssl_free;
+    nstat = (bstatus == V_OCSP_CERTSTATUS_GOOD)? MD_OCSP_CERT_ST_GOOD : MD_OCSP_CERT_ST_REVOKED;
+    valid.start = bup? md_asn1_generalized_time_get(bup) : apr_time_now();
+    valid.end = md_asn1_generalized_time_get(bnextup);
+    
+    /* First, update the instance with a copy */
+    apr_thread_mutex_lock(ostat->reg->mutex);
+    ostat_set(ostat, nstat, &new_der, &valid, apr_time_now());
+    apr_thread_mutex_unlock(ostat->reg->mutex);
+    
+    /* Next, save the original response */
+    rv = ocsp_status_save(nstat, &new_der, &valid, ostat, req->pool); 
+    if (APR_SUCCESS != rv) {
+        md_result_set(update->result, rv, "error saving OCSP status");
+        md_result_log(update->result, MD_LOG_ERR);
+        goto cleanup;
+    }
+    
+    md_result_printf(update->result, rv, "certificate status is %s, status valid %s", 
+                     (nstat == MD_OCSP_CERT_ST_GOOD)? "GOOD" : "REVOKED",
+                     md_timeperiod_print(req->pool, &ostat->resp_valid));
+    md_result_log(update->result, MD_LOG_DEBUG);
+
+cleanup:
+    md_data_clear(&new_der);
+    if (basic_resp) OCSP_BASICRESP_free(basic_resp);
+    if (ocsp_resp) OCSP_RESPONSE_free(ocsp_resp);
+    return rv;
+}
+
+static apr_status_t ostat_on_req_status(const md_http_request_t *req, apr_status_t status, 
+                                        void *baton)
+{
+    md_ocsp_update_t *update = baton;
+    md_ocsp_status_t *ostat = update->ostat;
+
+    (void)req;
+    md_job_end_run(update->job, update->result);
+    if (APR_SUCCESS != status) {
+        ++ostat->errors;
+        ostat->next_run = apr_time_now() + md_job_delay_on_errors(update->job, ostat->errors, NULL);
+        md_result_printf(update->result, status, "OCSP status update failed (%d. time)",  
+                         ostat->errors);
+        md_result_log(update->result, MD_LOG_DEBUG);
+        md_job_log_append(update->job, "ocsp-error", 
+                          update->result->problem, update->result->detail);
+        md_event_holler("ocsp-errored", update->job->mdomain, update->job, update->result, update->p);
+        goto cleanup;
+    }
+    md_event_holler("ocsp-renewed", update->job->mdomain, update->job, update->result, update->p);
+
+cleanup:
+    md_job_save(update->job, update->result, update->p);
+    ostat_req_cleanup(ostat);
+    return APR_SUCCESS;
+}
+
+typedef struct {
+    md_ocsp_reg_t *reg;
+    apr_array_header_t *todos;
+    apr_pool_t *ptemp;
+    apr_time_t time;
+    int max_parallel;
+} md_ocsp_todo_ctx_t;
+
+static apr_status_t ocsp_req_make(OCSP_REQUEST **pocsp_req, OCSP_CERTID *certid)
+{
+    OCSP_REQUEST *req = NULL;
+    OCSP_CERTID *id_copy = NULL;
+    apr_status_t rv = APR_ENOMEM;
+
+    req = OCSP_REQUEST_new();
+    if (!req) goto cleanup;
+    id_copy = OCSP_CERTID_dup(certid);
+    if (!id_copy) goto cleanup;
+    if (!OCSP_request_add0_id(req, id_copy)) goto cleanup;
+    id_copy = NULL;
+    OCSP_request_add1_nonce(req, 0, -1);
+    rv = APR_SUCCESS;
+cleanup:
+    if (id_copy) OCSP_CERTID_free(id_copy);
+    if (APR_SUCCESS != rv && req) {
+        OCSP_REQUEST_free(req);
+        req = NULL;
+    }
+    *pocsp_req = req;
+    return rv;
+}
+
+static apr_status_t ocsp_req_assign_der(md_data_t *d, OCSP_REQUEST *ocsp_req)
+{
+    int len;
+
+    md_data_clear(d);
+    len = i2d_OCSP_REQUEST(ocsp_req, (unsigned char**)&d->data);
+    if (len < 0) return APR_ENOMEM;
+    d->len = (apr_size_t)len;
+    d->free_data = md_openssl_free;
+    return APR_SUCCESS;
+}
+
+static apr_status_t next_todo(md_http_request_t **preq, void *baton, 
+                              md_http_t *http, int in_flight)
+{
+    md_ocsp_todo_ctx_t *ctx = baton;
+    md_ocsp_update_t *update, **pupdate;    
+    md_ocsp_status_t *ostat;
+    md_http_request_t *req = NULL;
+    apr_status_t rv = APR_ENOENT;
+    apr_table_t *headers;
+
+    if (in_flight < ctx->max_parallel) {
+        pupdate = apr_array_pop(ctx->todos);
+        if (pupdate) {
+            update = *pupdate;
+            ostat = update->ostat;
+            
+            update->job = md_ocsp_job_make(ctx->reg, ostat->md_name, update->p);
+            md_job_load(update->job);
+            md_job_start_run(update->job, update->result, ctx->reg->store);
+             
+            if (!ostat->ocsp_req) {
+                rv = ocsp_req_make(&ostat->ocsp_req, ostat->certid);
+                if (APR_SUCCESS != rv) goto cleanup;
+            }
+            if (0 == ostat->req_der.len) {
+                rv = ocsp_req_assign_der(&ostat->req_der, ostat->ocsp_req);
+                if (APR_SUCCESS != rv) goto cleanup;
+            }
+            md_result_activity_printf(update->result, "status of certid %s, "
+                                      "contacting %s", ostat->hexid, ostat->responder_url);
+            headers = apr_table_make(ctx->ptemp, 5);
+            apr_table_set(headers, "Expect", "");
+            rv = md_http_POSTd_create(&req, http, ostat->responder_url, headers, 
+                                      "application/ocsp-request", &ostat->req_der);
+            if (APR_SUCCESS != rv) goto cleanup;
+            md_http_set_on_status_cb(req, ostat_on_req_status, update);
+            md_http_set_on_response_cb(req, ostat_on_resp, update);
+            rv = APR_SUCCESS;
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, req->pool,
+                          "scheduling OCSP request[%d] for %s, %d request in flight",
+                          req->id, ostat->md_name, in_flight);
+        }
+    }
+cleanup:
+    *preq = (APR_SUCCESS == rv)? req : NULL;
+    return rv;
+}
+
+static int select_updates(void *baton, const void *key, apr_ssize_t klen, const void *val)
+{
+    md_ocsp_todo_ctx_t *ctx = baton;
+    md_ocsp_status_t *ostat = (md_ocsp_status_t *)val;
+    md_ocsp_update_t *update;
+    
+    (void)key;
+    (void)klen;
+    if (ostat->next_run <= ctx->time) {
+        update = apr_pcalloc(ctx->ptemp, sizeof(*update));
+        update->p = ctx->ptemp;
+        update->ostat = ostat;
+        update->result = md_result_md_make(update->p, ostat->md_name);
+        update->job = NULL;
+        APR_ARRAY_PUSH(ctx->todos, md_ocsp_update_t*) = update;
+    }
+    return 1;
+}
+
+static int select_next_run(void *baton, const void *key, apr_ssize_t klen, const void *val)
+{
+    md_ocsp_todo_ctx_t *ctx = baton;
+    md_ocsp_status_t *ostat = (md_ocsp_status_t *)val;
+    
+    (void)key;
+    (void)klen;
+    if (ostat->next_run < ctx->time && ostat->next_run > apr_time_now()) {
+        ctx->time = ostat->next_run;
+    }
+    return 1;
+}
+
+void md_ocsp_renew(md_ocsp_reg_t *reg, apr_pool_t *p, apr_pool_t *ptemp, apr_time_t *pnext_run)
+{
+    md_ocsp_todo_ctx_t ctx;
+    md_http_t *http;
+    apr_status_t rv = APR_SUCCESS;
+    
+    (void)p;
+    (void)pnext_run;
+    
+    ctx.reg = reg;
+    ctx.ptemp = ptemp;
+    ctx.todos = apr_array_make(ptemp, (int)md_ocsp_count(reg), sizeof(md_ocsp_status_t*));
+    ctx.max_parallel = 6; /* the magic number in HTTP */
+    
+    /* Create a list of update tasks that are needed now or in the next minute */
+    ctx.time = apr_time_now() + apr_time_from_sec(60);;
+    apr_hash_do(select_updates, &ctx, reg->ostat_by_id);
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, 
+                  "OCSP status updates due: %d",  ctx.todos->nelts);
+    if (!ctx.todos->nelts) goto cleanup;
+    
+    rv = md_http_create(&http, ptemp, reg->user_agent, reg->proxy_url);
+    if (APR_SUCCESS != rv) goto cleanup;
+    
+    rv = md_http_multi_perform(http, next_todo, &ctx);
+
+cleanup:
+    /* When do we need to run next? *pnext_run contains the planned schedule from
+     * the watchdog. We can make that earlier if we need it. */
+    ctx.time = *pnext_run;
+    apr_hash_do(select_next_run, &ctx, reg->ostat_by_id);
+
+    /* sanity check and return */
+    if (ctx.time < apr_time_now()) ctx.time = apr_time_now() + apr_time_from_sec(1);
+    *pnext_run = ctx.time;
+
+    if (APR_SUCCESS != rv && APR_ENOENT != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "ocsp_renew done");
+    }
+    return;
+}
+
+apr_status_t md_ocsp_remove_responses_older_than(md_ocsp_reg_t *reg, apr_pool_t *p, 
+                                                 apr_time_t timestamp)
+{
+    return md_store_remove_not_modified_since(reg->store, p, timestamp, 
+                                              MD_SG_OCSP, "*", "ocsp*.json");
+}
+
+typedef struct {
+    apr_pool_t *p;
+    md_ocsp_reg_t *reg;
+    int good;
+    int revoked;
+    int unknown;
+} ocsp_summary_ctx_t;
+
+static int add_to_summary(void *baton, const void *key, apr_ssize_t klen, const void *val)
+{
+    ocsp_summary_ctx_t *ctx = baton;
+    md_ocsp_status_t *ostat = (md_ocsp_status_t *)val;
+    md_ocsp_cert_stat_t stat;
+    md_timeperiod_t valid;
+    
+    (void)key;
+    (void)klen;
+    ocsp_get_meta(&stat, &valid, ctx->reg, ostat, ctx->p);
+    switch (stat) {
+        case MD_OCSP_CERT_ST_GOOD: ++ctx->good; break;
+        case MD_OCSP_CERT_ST_REVOKED: ++ctx->revoked; break;
+        case MD_OCSP_CERT_ST_UNKNOWN: ++ctx->unknown; break;
+    }
+    return 1;
+}
+
+void  md_ocsp_get_summary(md_json_t **pjson, md_ocsp_reg_t *reg, apr_pool_t *p)
+{
+    md_json_t *json;
+    ocsp_summary_ctx_t ctx;
+    
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.p = p;
+    ctx.reg = reg;
+    apr_hash_do(add_to_summary, &ctx, reg->ostat_by_id);
+
+    json = md_json_create(p);
+    md_json_setl(ctx.good+ctx.revoked+ctx.unknown, json, MD_KEY_TOTAL, NULL);
+    md_json_setl(ctx.good, json, MD_KEY_GOOD, NULL);
+    md_json_setl(ctx.revoked, json, MD_KEY_REVOKED, NULL);
+    md_json_setl(ctx.unknown, json, MD_KEY_UNKNOWN, NULL);
+    *pjson = json;
+}
+
+static apr_status_t job_loadj(md_json_t **pjson, const char *name, 
+                              md_ocsp_reg_t *reg, apr_pool_t *p)
+{
+    return md_store_load_json(reg->store, MD_SG_OCSP, name, MD_FN_JOB, pjson, p);
+}
+
+typedef struct {
+    apr_pool_t *p;
+    md_ocsp_reg_t *reg;
+    apr_array_header_t *ostats;
+} ocsp_status_ctx_t;
+
+static md_json_t *mk_jstat(md_ocsp_status_t *ostat, md_ocsp_reg_t *reg, apr_pool_t *p)
+{
+    md_ocsp_cert_stat_t stat;
+    md_timeperiod_t valid, renewal;
+    md_json_t *json, *jobj;
+    apr_status_t rv;
+    
+    json = md_json_create(p);
+    md_json_sets(ostat->md_name, json, MD_KEY_DOMAIN, NULL);
+    md_json_sets(ostat->hexid, json, MD_KEY_ID, NULL);
+    ocsp_get_meta(&stat, &valid, reg, ostat, p);
+    md_json_sets(md_ocsp_cert_stat_name(stat), json, MD_KEY_STATUS, NULL);
+    md_json_sets(ostat->hex_sha256, json, MD_KEY_CERT, MD_KEY_SHA256_FINGERPRINT, NULL);
+    md_json_sets(ostat->responder_url, json, MD_KEY_URL, NULL);
+    md_json_set_timeperiod(&valid, json, MD_KEY_VALID, NULL);
+    renewal = md_timeperiod_slice_before_end(&valid, &reg->renew_window);
+    md_json_set_time(renewal.start, json, MD_KEY_RENEW_AT, NULL);
+    if ((MD_OCSP_CERT_ST_UNKNOWN == stat) || renewal.start < apr_time_now()) {
+        /* We have no answer yet, or it should be in renew now. Add job information */
+        rv = job_loadj(&jobj, ostat->md_name, reg, p);
+        if (APR_SUCCESS == rv) {
+            md_json_setj(jobj, json, MD_KEY_RENEWAL, NULL);
+        }
+    }
+    return json;
+}
+
+static int add_ostat(void *baton, const void *key, apr_ssize_t klen, const void *val)
+{
+    ocsp_status_ctx_t *ctx = baton;
+    const md_ocsp_status_t *ostat = val;
+    
+    (void)key;
+    (void)klen;
+    APR_ARRAY_PUSH(ctx->ostats, const md_ocsp_status_t*) = ostat;
+    return 1;
+}
+
+static int md_ostat_cmp(const void *v1, const void *v2)
+{
+    int n;
+    n = strcmp((*(md_ocsp_status_t**)v1)->md_name, (*(md_ocsp_status_t**)v2)->md_name);
+    if (!n) {
+        n = strcmp((*(md_ocsp_status_t**)v1)->hexid, (*(md_ocsp_status_t**)v2)->hexid);
+    }
+    return n;
+}
+
+void md_ocsp_get_status_all(md_json_t **pjson, md_ocsp_reg_t *reg, apr_pool_t *p)
+{
+    md_json_t *json;
+    ocsp_status_ctx_t ctx;
+    md_ocsp_status_t *ostat;
+    int i;
+    
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.p = p;
+    ctx.reg = reg;
+    ctx.ostats = apr_array_make(p, (int)apr_hash_count(reg->ostat_by_id), sizeof(md_ocsp_status_t*));
+    json = md_json_create(p);
+    
+    apr_hash_do(add_ostat, &ctx, reg->ostat_by_id);
+    qsort(ctx.ostats->elts, (size_t)ctx.ostats->nelts, sizeof(md_json_t*), md_ostat_cmp);
+    
+    for (i = 0; i < ctx.ostats->nelts; ++i) {
+        ostat = APR_ARRAY_IDX(ctx.ostats, i, md_ocsp_status_t*);
+        md_json_addj(mk_jstat(ostat, reg, p), json, MD_KEY_OCSPS, NULL);
+    }
+    *pjson = json;
+}
+
+md_job_t *md_ocsp_job_make(md_ocsp_reg_t *ocsp, const char *mdomain, apr_pool_t *p)
+{
+    return md_job_make(p, ocsp->store, MD_SG_OCSP, mdomain, ocsp->min_delay);
+}
diff --git a/modules/md/md_ocsp.h b/modules/md/md_ocsp.h
new file mode 100644
index 0000000..c91dc54
--- /dev/null
+++ b/modules/md/md_ocsp.h
@@ -0,0 +1,71 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef md_ocsp_h
+#define md_ocsp_h
+
+struct md_data_t;
+struct md_job_t;
+struct md_json_t;
+struct md_result_t;
+struct md_store_t;
+struct md_timeslice_t;
+
+typedef enum {
+    MD_OCSP_CERT_ST_UNKNOWN,
+    MD_OCSP_CERT_ST_GOOD,
+    MD_OCSP_CERT_ST_REVOKED,
+} md_ocsp_cert_stat_t;
+
+const char *md_ocsp_cert_stat_name(md_ocsp_cert_stat_t stat);
+md_ocsp_cert_stat_t md_ocsp_cert_stat_value(const char *name);
+
+typedef struct md_ocsp_reg_t md_ocsp_reg_t;
+
+apr_status_t md_ocsp_reg_make(md_ocsp_reg_t **preg, apr_pool_t *p,
+                              struct md_store_t *store, 
+                              const md_timeslice_t *renew_window,
+                              const char *user_agent, const char *proxy_url,
+                              apr_time_t min_delay);
+
+apr_status_t md_ocsp_init_id(struct md_data_t *id, apr_pool_t *p, const md_cert_t *cert);
+
+apr_status_t md_ocsp_prime(md_ocsp_reg_t *reg, const char *ext_id, apr_size_t ext_id_len,
+                           md_cert_t *x, md_cert_t *issuer, const md_t *md);
+
+typedef void md_ocsp_copy_der(const unsigned char *der, apr_size_t der_len, void *userdata);
+
+apr_status_t md_ocsp_get_status(md_ocsp_copy_der *cb, void *userdata, md_ocsp_reg_t *reg,
+                                const char *ext_id, apr_size_t ext_id_len,
+                                apr_pool_t *p, const md_t *md);
+
+apr_status_t md_ocsp_get_meta(md_ocsp_cert_stat_t *pstat, md_timeperiod_t *pvalid,
+                              md_ocsp_reg_t *reg, const md_cert_t *cert,
+                              apr_pool_t *p, const md_t *md);
+
+apr_size_t md_ocsp_count(md_ocsp_reg_t *reg);
+
+void md_ocsp_renew(md_ocsp_reg_t *reg, apr_pool_t *p, apr_pool_t *ptemp, apr_time_t *pnext_run);
+
+apr_status_t md_ocsp_remove_responses_older_than(md_ocsp_reg_t *reg, apr_pool_t *p, 
+                                                 apr_time_t timestamp);
+
+void md_ocsp_get_summary(struct md_json_t **pjson, md_ocsp_reg_t *reg, apr_pool_t *p);
+void md_ocsp_get_status_all(struct md_json_t **pjson, md_ocsp_reg_t *reg, apr_pool_t *p);
+
+struct md_job_t *md_ocsp_job_make(md_ocsp_reg_t *ocsp, const char *mdomain, apr_pool_t *p);
+
+#endif /* md_ocsp_h */
diff --git a/modules/md/md_reg.c b/modules/md/md_reg.c
new file mode 100644
index 0000000..8bceb0e
--- /dev/null
+++ b/modules/md/md_reg.c
@@ -0,0 +1,1323 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_hash.h>
+#include <apr_strings.h>
+#include <apr_uri.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_event.h"
+#include "md_log.h"
+#include "md_json.h"
+#include "md_result.h"
+#include "md_reg.h"
+#include "md_store.h"
+#include "md_status.h"
+#include "md_tailscale.h"
+#include "md_util.h"
+
+#include "md_acme.h"
+#include "md_acme_acct.h"
+
+struct md_reg_t {
+    apr_pool_t *p;
+    struct md_store_t *store;
+    struct apr_hash_t *protos;
+    struct apr_hash_t *certs;
+    int can_http;
+    int can_https;
+    const char *proxy_url;
+    const char *ca_file;
+    int domains_frozen;
+    md_timeslice_t *renew_window;
+    md_timeslice_t *warn_window;
+    md_job_notify_cb *notify;
+    void *notify_ctx;
+    apr_time_t min_delay;
+    int retry_failover;
+    int use_store_locks;
+    apr_time_t lock_wait_timeout;
+};
+
+/**************************************************************************************************/
+/* life cycle */
+
+static apr_status_t load_props(md_reg_t *reg, apr_pool_t *p)
+{
+    md_json_t *json;
+    apr_status_t rv;
+    
+    rv = md_store_load(reg->store, MD_SG_NONE, NULL, MD_FN_HTTPD_JSON, 
+                       MD_SV_JSON, (void**)&json, p);
+    if (APR_SUCCESS == rv) {
+        if (md_json_has_key(json, MD_KEY_PROTO, MD_KEY_HTTP, NULL)) {
+            reg->can_http = md_json_getb(json, MD_KEY_PROTO, MD_KEY_HTTP, NULL);
+        }
+        if (md_json_has_key(json, MD_KEY_PROTO, MD_KEY_HTTPS, NULL)) {
+            reg->can_https = md_json_getb(json, MD_KEY_PROTO, MD_KEY_HTTPS, NULL);
+        }
+    }
+    else if (APR_STATUS_IS_ENOENT(rv)) {
+        rv = APR_SUCCESS;
+    }
+    return rv;
+}
+
+apr_status_t md_reg_create(md_reg_t **preg, apr_pool_t *p, struct md_store_t *store,
+                           const char *proxy_url, const char *ca_file,
+                           apr_time_t min_delay, int retry_failover,
+                           int use_store_locks, apr_time_t lock_wait_timeout)
+{
+    md_reg_t *reg;
+    apr_status_t rv;
+    
+    reg = apr_pcalloc(p, sizeof(*reg));
+    reg->p = p;
+    reg->store = store;
+    reg->protos = apr_hash_make(p);
+    reg->certs = apr_hash_make(p);
+    reg->can_http = 1;
+    reg->can_https = 1;
+    reg->proxy_url = proxy_url? apr_pstrdup(p, proxy_url) : NULL;
+    reg->ca_file = (ca_file && apr_strnatcasecmp("none", ca_file))?
+                    apr_pstrdup(p, ca_file) : NULL;
+    reg->min_delay = min_delay;
+    reg->retry_failover = retry_failover;
+    reg->use_store_locks = use_store_locks;
+    reg->lock_wait_timeout = lock_wait_timeout;
+
+    md_timeslice_create(&reg->renew_window, p, MD_TIME_LIFE_NORM, MD_TIME_RENEW_WINDOW_DEF); 
+    md_timeslice_create(&reg->warn_window, p, MD_TIME_LIFE_NORM, MD_TIME_WARN_WINDOW_DEF); 
+    
+    if (APR_SUCCESS == (rv = md_acme_protos_add(reg->protos, p))
+        && APR_SUCCESS == (rv = md_tailscale_protos_add(reg->protos, p))) {
+        rv = load_props(reg, p);
+    }
+    
+    *preg = (rv == APR_SUCCESS)? reg : NULL;
+    return rv;
+}
+
+struct md_store_t *md_reg_store_get(md_reg_t *reg)
+{
+    return reg->store;
+}
+
+/**************************************************************************************************/
+/* checks */
+
+static apr_status_t check_values(md_reg_t *reg, apr_pool_t *p, const md_t *md, int fields)
+{
+    apr_status_t rv = APR_SUCCESS;
+    const char *err = NULL;
+    
+    if (MD_UPD_DOMAINS & fields) {
+        const md_t *other;
+        const char *domain;
+        int i;
+        
+        if (!md->domains || md->domains->nelts <= 0) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, APR_EINVAL, p, 
+                          "empty domain list: %s", md->name);
+            return APR_EINVAL;
+        }
+        
+        for (i = 0; i < md->domains->nelts; ++i) {
+            domain = APR_ARRAY_IDX(md->domains, i, const char *);
+            if (!md_dns_is_name(p, domain, 1) && !md_dns_is_wildcard(p, domain)) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, APR_EINVAL, p, 
+                              "md %s with invalid domain name: %s", md->name, domain);
+                return APR_EINVAL;
+            }
+        }
+
+        if (NULL != (other = md_reg_find_overlap(reg, md, &domain, p))) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, APR_EINVAL, p, 
+                          "md %s shares domain '%s' with md %s", 
+                          md->name, domain, other->name);
+            return APR_EINVAL;
+        }
+    }
+    
+    if (MD_UPD_CONTACTS & fields) {
+        const char *contact;
+        int i;
+
+        for (i = 0; i < md->contacts->nelts && !err; ++i) {
+            contact = APR_ARRAY_IDX(md->contacts, i, const char *);
+            rv = md_util_abs_uri_check(p, contact, &err);
+            
+            if (err) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, APR_EINVAL, p, 
+                              "contact for %s invalid (%s): %s", md->name, err, contact);
+                return APR_EINVAL;
+            }
+        }
+    }
+    
+    if ((MD_UPD_CA_URL & fields) && md->ca_urls) { /* setting to empty is ok */
+        int i;
+        const char *url;
+        for (i = 0; i < md->ca_urls->nelts; ++i) {
+            url = APR_ARRAY_IDX(md->ca_urls, i, const char*);
+            rv = md_util_abs_uri_check(p, url, &err);
+            if (err) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, APR_EINVAL, p,
+                              "CA url for %s invalid (%s): %s", md->name, err, url);
+                return APR_EINVAL;
+            }
+        }
+    }
+    
+    if ((MD_UPD_CA_PROTO & fields) && md->ca_proto) { /* setting to empty is ok */
+        /* Do we want to restrict this to "known" protocols? */
+    }
+    
+    if ((MD_UPD_CA_ACCOUNT & fields) && md->ca_account) { /* setting to empty is ok */
+        /* hmm, in case we know the protocol, some checks could be done */
+    }
+
+    if ((MD_UPD_AGREEMENT & fields) && md->ca_agreement
+        && strcmp("accepted", md->ca_agreement)) { /* setting to empty is ok */
+        rv = md_util_abs_uri_check(p, md->ca_agreement, &err);
+        if (err) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, APR_EINVAL, p, 
+                          "CA url for %s invalid (%s): %s", md->name, err, md->ca_agreement);
+            return APR_EINVAL;
+        }
+    }
+
+    return rv;
+}
+
+/**************************************************************************************************/
+/* state assessment */
+
+static apr_status_t state_init(md_reg_t *reg, apr_pool_t *p, md_t *md)
+{
+    md_state_t state = MD_S_COMPLETE;
+    const char *state_descr = NULL;
+    const md_pubcert_t *pub;
+    const md_cert_t *cert;
+    const md_pkey_spec_t *spec;
+    apr_status_t rv = APR_SUCCESS;
+    int i;
+
+    if (md->renew_window == NULL) md->renew_window = reg->renew_window;
+    if (md->warn_window == NULL) md->warn_window = reg->warn_window;
+
+    if (md->domains && md->domains->pool != p) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p,
+                      "md{%s}: state_init called with foreign pool", md->name);
+    }
+
+    for (i = 0; i < md_cert_count(md); ++i) {
+        spec = md_pkeys_spec_get(md->pks, i);
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, rv, p,
+                      "md{%s}: check cert %s", md->name, md_pkey_spec_name(spec));
+        rv = md_reg_get_pubcert(&pub, reg, md, i, p);
+        if (APR_SUCCESS == rv) {
+            cert = APR_ARRAY_IDX(pub->certs, 0, const md_cert_t*);
+            if (!md_is_covered_by_alt_names(md, pub->alt_names)) {
+                state = MD_S_INCOMPLETE;
+                state_descr = apr_psprintf(p, "certificate(%s) does not cover all domains.",
+                                           md_pkey_spec_name(spec));
+                goto cleanup;
+            }
+            if (!md->must_staple != !md_cert_must_staple(cert)) {
+                state = MD_S_INCOMPLETE;
+                state_descr = apr_psprintf(p, "'must-staple' is%s requested, but "
+                              "certificate(%s) has it%s enabled.",
+                              md->must_staple? "" : " not",
+                              md_pkey_spec_name(spec),
+                              !md->must_staple? "" : " not");
+                goto cleanup;
+            }
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p, "md{%s}: certificate(%d) is ok",
+                          md->name, i);
+        }
+        else if (APR_STATUS_IS_ENOENT(rv)) {
+            state = MD_S_INCOMPLETE;
+            state_descr = apr_psprintf(p, "certificate(%s) is missing",
+                                       md_pkey_spec_name(spec));
+            rv = APR_SUCCESS;
+            goto cleanup;
+        }
+        else {
+            state = MD_S_ERROR;
+            state_descr = "error initializing";
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, p, "md{%s}: error", md->name);
+            goto cleanup;
+        }
+    }
+
+cleanup:
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, rv, p, "md{%s}: state=%d, %s",
+                  md->name, state, state_descr);
+    md->state = state;
+    md->state_descr = state_descr;
+    return rv;
+}
+
+/**************************************************************************************************/
+/* iteration */
+
+typedef struct {
+    md_reg_t *reg;
+    md_reg_do_cb *cb;
+    void *baton;
+    const char *exclude;
+    const void *result;
+} reg_do_ctx;
+
+static int reg_md_iter(void *baton, md_store_t *store, md_t *md, apr_pool_t *ptemp)
+{
+    reg_do_ctx *ctx = baton;
+    
+    (void)store;
+    if (!ctx->exclude || strcmp(ctx->exclude, md->name)) {
+        state_init(ctx->reg, ptemp, (md_t*)md);
+        return ctx->cb(ctx->baton, ctx->reg, md);
+    }
+    return 1;
+}
+
+static int reg_do(md_reg_do_cb *cb, void *baton, md_reg_t *reg, apr_pool_t *p, const char *exclude)
+{
+    reg_do_ctx ctx;
+    
+    ctx.reg = reg;
+    ctx.cb = cb;
+    ctx.baton = baton;
+    ctx.exclude = exclude;
+    return md_store_md_iter(reg_md_iter, &ctx, reg->store, p, MD_SG_DOMAINS, "*");
+}
+
+
+int md_reg_do(md_reg_do_cb *cb, void *baton, md_reg_t *reg, apr_pool_t *p)
+{
+    return reg_do(cb, baton, reg, p, NULL);
+}
+
+/**************************************************************************************************/
+/* lookup */
+
+md_t *md_reg_get(md_reg_t *reg, const char *name, apr_pool_t *p)
+{
+    md_t *md;
+    
+    if (APR_SUCCESS == md_load(reg->store, MD_SG_DOMAINS, name, &md, p)) {
+        state_init(reg, p, md);
+        return md;
+    }
+    return NULL;
+}
+
+typedef struct {
+    const char *domain;
+    md_t *md;
+} find_domain_ctx;
+
+static int find_domain(void *baton, md_reg_t *reg, md_t *md)
+{
+    find_domain_ctx *ctx = baton;
+    
+    (void)reg;
+    if (md_contains(md, ctx->domain, 0)) {
+        ctx->md = md;
+        return 0;
+    }
+    return 1;
+}
+
+md_t *md_reg_find(md_reg_t *reg, const char *domain, apr_pool_t *p)
+{
+    find_domain_ctx ctx;
+
+    ctx.domain = domain;
+    ctx.md = NULL;
+    
+    md_reg_do(find_domain, &ctx, reg, p);
+    if (ctx.md) {
+        state_init(reg, p, ctx.md);
+    }
+    return ctx.md;
+}
+
+typedef struct {
+    const md_t *md_checked;
+    md_t *md;
+    const char *s;
+} find_overlap_ctx;
+
+static int find_overlap(void *baton, md_reg_t *reg, md_t *md)
+{
+    find_overlap_ctx *ctx = baton;
+    const char *overlap;
+    
+    (void)reg;
+    if ((overlap = md_common_name(ctx->md_checked, md))) {
+        ctx->md = md;
+        ctx->s = overlap;
+        return 0;
+    }
+    return 1;
+}
+
+md_t *md_reg_find_overlap(md_reg_t *reg, const md_t *md, const char **pdomain, apr_pool_t *p)
+{
+    find_overlap_ctx ctx;
+    
+    ctx.md_checked = md;
+    ctx.md = NULL;
+    ctx.s = NULL;
+    
+    reg_do(find_overlap, &ctx, reg, p, md->name);
+    if (pdomain && ctx.s) {
+        *pdomain = ctx.s;
+    }
+    if (ctx.md) {
+        state_init(reg, p, ctx.md);
+    }
+    return ctx.md;
+}
+
+/**************************************************************************************************/
+/* manipulation */
+
+static apr_status_t p_md_add(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_reg_t *reg = baton;
+    apr_status_t rv = APR_SUCCESS;
+    md_t *md, *mine;
+    int do_check;
+    
+    md = va_arg(ap, md_t *);
+    do_check = va_arg(ap, int);
+
+    if (reg->domains_frozen) return APR_EACCES; 
+    mine = md_clone(ptemp, md);
+    if (do_check && APR_SUCCESS != (rv = check_values(reg, ptemp, md, MD_UPD_ALL))) goto leave;
+    if (APR_SUCCESS != (rv = state_init(reg, ptemp, mine))) goto leave;
+    rv = md_save(reg->store, p, MD_SG_DOMAINS, mine, 1);
+leave:
+    return rv;
+}
+
+static apr_status_t add_md(md_reg_t *reg, md_t *md, apr_pool_t *p, int do_checks)
+{
+    return md_util_pool_vdo(p_md_add, reg, p, md, do_checks, NULL);
+}
+
+apr_status_t md_reg_add(md_reg_t *reg, md_t *md, apr_pool_t *p)
+{
+    return add_md(reg, md, p, 1);
+}
+
+static apr_status_t p_md_update(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_reg_t *reg = baton;
+    apr_status_t rv = APR_SUCCESS;
+    const char *name;
+    const md_t *md, *updates;
+    int fields, do_checks;
+    md_t *nmd;
+    
+    name = va_arg(ap, const char *);
+    updates = va_arg(ap, const md_t *);
+    fields = va_arg(ap, int);
+    do_checks = va_arg(ap, int);
+    
+    if (NULL == (md = md_reg_get(reg, name, ptemp))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, APR_ENOENT, ptemp, "md %s", name);
+        return APR_ENOENT;
+    }
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, ptemp, "md[%s]: update store", name);
+    
+    if (do_checks && APR_SUCCESS != (rv = check_values(reg, ptemp, updates, fields))) {
+        return rv;
+    }
+    
+    if (reg->domains_frozen) return APR_EACCES; 
+    nmd = md_copy(ptemp, md);
+    if (MD_UPD_DOMAINS & fields) {
+        nmd->domains = updates->domains;
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update domains: %s", name);
+    }
+    if (MD_UPD_CA_URL & fields) {
+        nmd->ca_urls = (updates->ca_urls?
+                        apr_array_copy(p, updates->ca_urls) : NULL);
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update ca url: %s", name);
+    }
+    if (MD_UPD_CA_PROTO & fields) {
+        nmd->ca_proto = updates->ca_proto;
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update ca protocol: %s", name);
+    }
+    if (MD_UPD_CA_ACCOUNT & fields) {
+        nmd->ca_account = updates->ca_account;
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update account: %s", name);
+    }
+    if (MD_UPD_CONTACTS & fields) {
+        nmd->contacts = updates->contacts;
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update contacts: %s", name);
+    }
+    if (MD_UPD_AGREEMENT & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update agreement: %s", name);
+        nmd->ca_agreement = updates->ca_agreement;
+    }
+    if (MD_UPD_DRIVE_MODE & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update drive-mode: %s", name);
+        nmd->renew_mode = updates->renew_mode;
+    }
+    if (MD_UPD_RENEW_WINDOW & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update renew-window: %s", name);
+        *nmd->renew_window = *updates->renew_window;
+    }
+    if (MD_UPD_WARN_WINDOW & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update warn-window: %s", name);
+        *nmd->warn_window = *updates->warn_window;
+    }
+    if (MD_UPD_CA_CHALLENGES & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update ca challenges: %s", name);
+        nmd->ca_challenges = (updates->ca_challenges? 
+                              apr_array_copy(p, updates->ca_challenges) : NULL);
+    }
+    if (MD_UPD_PKEY_SPEC & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update pkey spec: %s", name);
+        nmd->pks = md_pkeys_spec_clone(p, updates->pks);
+    }
+    if (MD_UPD_REQUIRE_HTTPS & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update require-https: %s", name);
+        nmd->require_https = updates->require_https;
+    }
+    if (MD_UPD_TRANSITIVE & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update transitive: %s", name);
+        nmd->transitive = updates->transitive;
+    }
+    if (MD_UPD_MUST_STAPLE & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update must-staple: %s", name);
+        nmd->must_staple = updates->must_staple;
+    }
+    if (MD_UPD_PROTO & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update proto: %s", name);
+        nmd->acme_tls_1_domains = updates->acme_tls_1_domains;
+    }
+    if (MD_UPD_STAPLING & fields) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "update stapling: %s", name);
+        nmd->stapling = updates->stapling;
+    }
+    
+    if (fields && APR_SUCCESS == (rv = md_save(reg->store, p, MD_SG_DOMAINS, nmd, 0))) {
+        rv = state_init(reg, ptemp, nmd);
+    }
+    return rv;
+}
+
+apr_status_t md_reg_update(md_reg_t *reg, apr_pool_t *p, 
+                           const char *name, const md_t *md, int fields, 
+                           int do_checks)
+{
+    return md_util_pool_vdo(p_md_update, reg, p, name, md, fields, do_checks, NULL);
+}
+
+apr_status_t md_reg_delete_acct(md_reg_t *reg, apr_pool_t *p, const char *acct_id) 
+{
+    apr_status_t rv = APR_SUCCESS;
+    
+    rv = md_store_remove(reg->store, MD_SG_ACCOUNTS, acct_id, MD_FN_ACCOUNT, p, 1);
+    if (APR_SUCCESS == rv) {
+        md_store_remove(reg->store, MD_SG_ACCOUNTS, acct_id, MD_FN_ACCT_KEY, p, 1);
+    }
+    return rv;
+}
+
+/**************************************************************************************************/
+/* certificate related */
+
+static apr_status_t pubcert_load(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_reg_t *reg = baton;
+    apr_array_header_t *certs;
+    md_pubcert_t *pubcert, **ppubcert;
+    const md_t *md;
+    int index;
+    const md_cert_t *cert;
+    md_cert_state_t cert_state;
+    md_store_group_t group;
+    apr_status_t rv;
+    
+    ppubcert = va_arg(ap, md_pubcert_t **);
+    group = (md_store_group_t)va_arg(ap, int);
+    md = va_arg(ap, const md_t *);
+    index = va_arg(ap, int);
+    
+    if (md->cert_files && md->cert_files->nelts) {
+        rv = md_chain_fload(&certs, p, APR_ARRAY_IDX(md->cert_files, index, const char *));
+    }
+    else {
+        md_pkey_spec_t *spec = md_pkeys_spec_get(md->pks, index);;
+        rv = md_pubcert_load(reg->store, group, md->name, spec, &certs, p);
+    }
+    if (APR_SUCCESS != rv) goto leave;
+    if (certs->nelts == 0) {
+        rv = APR_ENOENT;
+        goto leave;
+    }
+
+    pubcert = apr_pcalloc(p, sizeof(*pubcert));
+    pubcert->certs = certs;
+    cert = APR_ARRAY_IDX(certs, 0, const md_cert_t *);
+    if (APR_SUCCESS != (rv = md_cert_get_alt_names(&pubcert->alt_names, cert, p))) goto leave;
+    switch ((cert_state = md_cert_state_get(cert))) {
+        case MD_CERT_VALID:
+        case MD_CERT_EXPIRED:
+            break;
+        default:
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, APR_EINVAL, ptemp, 
+                          "md %s has unexpected cert state: %d", md->name, cert_state);
+            rv = APR_ENOTIMPL;
+            break;
+    }
+leave:
+    *ppubcert = (APR_SUCCESS == rv)? pubcert : NULL;
+    return rv;
+}
+
+apr_status_t md_reg_get_pubcert(const md_pubcert_t **ppubcert, md_reg_t *reg, 
+                                const md_t *md, int i, apr_pool_t *p)
+{
+    apr_status_t rv = APR_SUCCESS;
+    const md_pubcert_t *pubcert;
+    const char *name;
+
+    name = apr_psprintf(p, "%s[%d]", md->name, i);
+    pubcert = apr_hash_get(reg->certs, name, (apr_ssize_t)strlen(name));
+    if (!pubcert && !reg->domains_frozen) {
+        rv = md_util_pool_vdo(pubcert_load, reg, reg->p, &pubcert, MD_SG_DOMAINS, md, i, NULL);
+        if (APR_STATUS_IS_ENOENT(rv)) {
+            /* We cache it missing with an empty record */
+            pubcert = apr_pcalloc(reg->p, sizeof(*pubcert));
+        }
+        else if (APR_SUCCESS != rv) goto leave;
+        if (p != reg->p) name = apr_pstrdup(reg->p, name);
+        apr_hash_set(reg->certs, name, (apr_ssize_t)strlen(name), pubcert);
+    }
+leave:
+    if (APR_SUCCESS == rv && (!pubcert || !pubcert->certs)) {
+        rv = APR_ENOENT;
+    }
+    *ppubcert = (APR_SUCCESS == rv)? pubcert : NULL;
+    return rv;
+}
+
+apr_status_t md_reg_get_cred_files(const char **pkeyfile, const char **pcertfile,
+                                   md_reg_t *reg, md_store_group_t group, 
+                                   const md_t *md, md_pkey_spec_t *spec, apr_pool_t *p)
+{
+    apr_status_t rv;
+    
+    rv = md_store_get_fname(pkeyfile, reg->store, group, md->name, md_pkey_filename(spec, p), p);
+    if (APR_SUCCESS != rv) return rv;
+    if (!md_file_exists(*pkeyfile, p)) return APR_ENOENT;
+    rv = md_store_get_fname(pcertfile, reg->store, group, md->name, md_chain_filename(spec, p), p);
+    if (APR_SUCCESS != rv) return rv;
+    if (!md_file_exists(*pcertfile, p)) return APR_ENOENT;
+    return APR_SUCCESS;
+}
+
+apr_time_t md_reg_valid_until(md_reg_t *reg, const md_t *md, apr_pool_t *p)
+{
+    const md_pubcert_t *pub;
+    const md_cert_t *cert;
+    int i;
+    apr_time_t t, valid_until = 0;
+    apr_status_t rv;
+    
+    for (i = 0; i < md_cert_count(md); ++i) {
+        rv = md_reg_get_pubcert(&pub, reg, md, i, p);
+        if (APR_SUCCESS == rv) {
+            cert = APR_ARRAY_IDX(pub->certs, 0, const md_cert_t*);
+            t = md_cert_get_not_after(cert);
+            if (valid_until == 0 || t < valid_until) {
+                valid_until = t;
+            }
+        }
+    }
+    return valid_until;
+}
+
+apr_time_t md_reg_renew_at(md_reg_t *reg, const md_t *md, apr_pool_t *p)
+{
+    const md_pubcert_t *pub;
+    const md_cert_t *cert;
+    md_timeperiod_t certlife, renewal;
+    int i;
+    apr_time_t renew_at = 0;
+    apr_status_t rv;
+    
+    if (md->state == MD_S_INCOMPLETE) return apr_time_now();
+    for (i = 0; i < md_cert_count(md); ++i) {
+        rv = md_reg_get_pubcert(&pub, reg, md, i, p);
+        if (APR_STATUS_IS_ENOENT(rv)) return apr_time_now();
+        if (APR_SUCCESS == rv) {
+            cert = APR_ARRAY_IDX(pub->certs, 0, const md_cert_t*);
+            certlife.start = md_cert_get_not_before(cert);
+            certlife.end = md_cert_get_not_after(cert);
+
+            renewal = md_timeperiod_slice_before_end(&certlife, md->renew_window);
+            if (md_log_is_level(p, MD_LOG_TRACE1)) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, p, 
+                              "md[%s]: certificate(%d) valid[%s] renewal[%s]", 
+                              md->name, i,  
+                              md_timeperiod_print(p, &certlife),
+                              md_timeperiod_print(p, &renewal));
+            }
+            
+            if (renew_at == 0 || renewal.start < renew_at) {
+                renew_at = renewal.start; 
+            }
+        }
+    }
+    return renew_at;
+}
+
+int md_reg_should_renew(md_reg_t *reg, const md_t *md, apr_pool_t *p) 
+{
+    apr_time_t renew_at;
+    
+    renew_at = md_reg_renew_at(reg, md, p);
+    return renew_at && (renew_at <= apr_time_now());
+}
+
+int md_reg_should_warn(md_reg_t *reg, const md_t *md, apr_pool_t *p)
+{
+    const md_pubcert_t *pub;
+    const md_cert_t *cert;
+    md_timeperiod_t certlife, warn;
+    int i;
+    apr_status_t rv;
+    
+    if (md->state == MD_S_INCOMPLETE) return 0;
+    for (i = 0; i < md_cert_count(md); ++i) {
+        rv = md_reg_get_pubcert(&pub, reg, md, i, p);
+        if (APR_STATUS_IS_ENOENT(rv)) return 0;
+        if (APR_SUCCESS == rv) {
+            cert = APR_ARRAY_IDX(pub->certs, 0, const md_cert_t*);
+            certlife.start = md_cert_get_not_before(cert);
+            certlife.end = md_cert_get_not_after(cert);
+            
+            warn = md_timeperiod_slice_before_end(&certlife, md->warn_window);
+            if (md_log_is_level(p, MD_LOG_TRACE1)) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, p, 
+                              "md[%s]: certificate(%d) life[%s] warn[%s]", 
+                              md->name, i,  
+                              md_timeperiod_print(p, &certlife),
+                              md_timeperiod_print(p, &warn));
+            }
+            if (md_timeperiod_has_started(&warn, apr_time_now())) {
+                return 1;
+            }
+        }
+    }
+    return 0;
+}
+
+/**************************************************************************************************/
+/* syncing */
+
+apr_status_t md_reg_set_props(md_reg_t *reg, apr_pool_t *p, int can_http, int can_https)
+{
+    if (reg->can_http != can_http || reg->can_https != can_https) {
+        md_json_t *json;
+        
+        if (reg->domains_frozen) return APR_EACCES; 
+        reg->can_http = can_http;
+        reg->can_https = can_https;
+        
+        json = md_json_create(p);
+        md_json_setb(can_http, json, MD_KEY_PROTO, MD_KEY_HTTP, NULL);
+        md_json_setb(can_https, json, MD_KEY_PROTO, MD_KEY_HTTPS, NULL);
+        
+        return md_store_save(reg->store, p, MD_SG_NONE, NULL, MD_FN_HTTPD_JSON, MD_SV_JSON, json, 0);
+    }
+    return APR_SUCCESS;
+}
+
+static md_t *find_closest_match(apr_array_header_t *mds, const md_t *md)
+{
+    md_t *candidate, *m;
+    apr_size_t cand_n, n;
+    int i;
+    
+    candidate = md_get_by_name(mds, md->name);
+    if (!candidate) {
+        /* try to find an instance that contains all domain names from md */ 
+        for (i = 0; i < mds->nelts; ++i) {
+            m = APR_ARRAY_IDX(mds, i, md_t *);
+            if (md_contains_domains(m, md)) {
+                return m;
+            }
+        }
+        /* no matching name and no md in the list has all domains.
+         * We consider that managed domain as closest match that contains at least one
+         * domain name from md, ONLY if there is no other one that also has.
+         */
+        cand_n = 0;
+        for (i = 0; i < mds->nelts; ++i) {
+            m = APR_ARRAY_IDX(mds, i, md_t *);
+            n = md_common_name_count(md, m);
+            if (n > cand_n) {
+                candidate = m;
+                cand_n = n;
+            }
+        }
+    }
+    return candidate;
+}
+
+typedef struct {
+    apr_pool_t *p;
+    apr_array_header_t *master_mds;
+    apr_array_header_t *store_names;
+    apr_array_header_t *maybe_new_mds;
+    apr_array_header_t *new_mds;
+    apr_array_header_t *unassigned_mds;
+} sync_ctx_v2;
+
+static int iter_add_name(void *baton, const char *dir, const char *name, 
+                         md_store_vtype_t vtype, void *value, apr_pool_t *ptemp)
+{
+    sync_ctx_v2 *ctx = baton;
+    
+    (void)dir;
+    (void)value;
+    (void)ptemp;
+    (void)vtype;
+    APR_ARRAY_PUSH(ctx->store_names, const char*) = apr_pstrdup(ctx->p, name);
+    return APR_SUCCESS;
+}
+
+/* A better scaling version:
+ *  1. The consistency of the MDs in 'master_mds' has already been verified. E.g.
+ *     that no domain lists overlap etc.
+ *  2. All MD storage that exists will be overwritten by the settings we have.
+ *     And "exists" meaning that "store/MD_SG_DOMAINS/name" exists.
+ *  3. For MDs that have no directory in "store/MD_SG_DOMAINS", we load all MDs
+ *     outside the list of known names from MD_SG_DOMAINS. In this list, we
+ *     look for the MD with the most domain overlap. 
+ *      - if we find it, we assume this is a rename and move the old MD to the new name.
+ *      - if not, MD is completely new.
+ *  4. Any MD in store that does not match the "master_mds" will just be left as is. 
+ */
+apr_status_t md_reg_sync_start(md_reg_t *reg, apr_array_header_t *master_mds, apr_pool_t *p) 
+{
+    sync_ctx_v2 ctx;
+    apr_status_t rv;
+    md_t *md, *oldmd;
+    const char *name;
+    int i, idx;
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, "sync MDs, start");
+     
+    ctx.p = p;
+    ctx.master_mds = master_mds;
+    ctx.store_names = apr_array_make(p, master_mds->nelts + 100, sizeof(const char*));
+    ctx.maybe_new_mds = apr_array_make(p, master_mds->nelts, sizeof(md_t*));
+    ctx.new_mds = apr_array_make(p, master_mds->nelts, sizeof(md_t*));
+    ctx.unassigned_mds = apr_array_make(p, master_mds->nelts, sizeof(md_t*));
+    
+    rv = md_store_iter_names(iter_add_name, &ctx, reg->store, p, MD_SG_DOMAINS, "*");
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "listing existing store MD names"); 
+        goto leave;
+    }
+    
+    /* Get all MDs that are not already present in store */
+    for (i = 0; i < ctx.master_mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(ctx.master_mds, i, md_t*);
+        idx = md_array_str_index(ctx.store_names, md->name, 0, 1);
+        if (idx < 0) {
+            APR_ARRAY_PUSH(ctx.maybe_new_mds, md_t*) = md;
+            md_array_remove_at(ctx.store_names, idx);
+        }
+    }
+    
+    if (ctx.maybe_new_mds->nelts == 0) goto leave; /* none new */
+    if (ctx.store_names->nelts == 0) goto leave;   /* all new */
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, 
+                  "sync MDs, %d potentially new MDs detected, looking for renames among "
+                  "the %d unassigned store domains", (int)ctx.maybe_new_mds->nelts,
+                  (int)ctx.store_names->nelts);
+    for (i = 0; i < ctx.store_names->nelts; ++i) {
+        name = APR_ARRAY_IDX(ctx.store_names, i, const char*);
+        if (APR_SUCCESS == md_load(reg->store, MD_SG_DOMAINS, name, &md, p)) {
+            APR_ARRAY_PUSH(ctx.unassigned_mds, md_t*) = md;
+        } 
+    }
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, 
+                  "sync MDs, %d MDs maybe new, checking store", (int)ctx.maybe_new_mds->nelts);
+    for (i = 0; i < ctx.maybe_new_mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(ctx.maybe_new_mds, i, md_t*);
+        oldmd = find_closest_match(ctx.unassigned_mds, md);
+        if (oldmd) {
+            /* found the rename, move the domains and possible staging directory */
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, 
+                          "sync MDs, found MD %s under previous name %s", md->name, oldmd->name);
+            rv = md_store_rename(reg->store, p, MD_SG_DOMAINS, oldmd->name, md->name);
+            if (APR_SUCCESS != rv) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, 
+                              "sync MDs, renaming MD %s to %s failed", oldmd->name, md->name);
+                /* ignore it? */
+            }
+            md_store_rename(reg->store, p, MD_SG_STAGING, oldmd->name, md->name);
+            md_array_remove(ctx.unassigned_mds, oldmd);
+        }
+        else {
+            APR_ARRAY_PUSH(ctx.new_mds, md_t*) = md;
+        }
+    }
+
+leave:
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, 
+                  "sync MDs, %d existing, %d moved, %d new.", 
+                  (int)ctx.master_mds->nelts - ctx.maybe_new_mds->nelts,
+                  (int)ctx.maybe_new_mds->nelts - ctx.new_mds->nelts,
+                  (int)ctx.new_mds->nelts);
+    return rv;
+}
+
+/** 
+ * Finish syncing an MD with the store. 
+ * 1. if there are changed properties (or if the MD is new), save it.
+ * 2. read any existing certificate and init the state of the memory MD
+ */
+apr_status_t md_reg_sync_finish(md_reg_t *reg, md_t *md, apr_pool_t *p, apr_pool_t *ptemp)
+{
+    md_t *old;
+    apr_status_t rv;
+    int changed = 1;
+    md_proto_t *proto;
+    
+    if (!md->ca_proto) {
+        md->ca_proto = MD_PROTO_ACME;
+    }
+    proto = apr_hash_get(reg->protos, md->ca_proto, (apr_ssize_t)strlen(md->ca_proto));
+    if (!proto) {
+        rv = APR_ENOTIMPL;
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, ptemp,
+                      "[%s] uses unknown CA protocol '%s'",
+                      md->name, md->ca_proto);
+        goto leave;
+    }
+    rv = proto->complete_md(md, p);
+    if (APR_SUCCESS != rv) goto leave;
+
+    rv = state_init(reg, p, md);
+    if (APR_SUCCESS != rv) goto leave;
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, ptemp, "loading md %s", md->name);
+    if (APR_SUCCESS == md_load(reg->store, MD_SG_DOMAINS, md->name, &old, ptemp)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, ptemp, "loaded md %s", md->name);
+        /* Some parts are kept from old, lacking new values */
+        if ((!md->contacts || apr_is_empty_array(md->contacts)) && old->contacts) {
+            md->contacts = md_array_str_clone(p, old->contacts);
+        } 
+        if (md->ca_challenges && old->ca_challenges) {
+            if (!md_array_str_eq(md->ca_challenges, old->ca_challenges, 0)) {
+                md->ca_challenges = md_array_str_compact(p, md->ca_challenges, 0);
+            }
+        }
+        if (!md->ca_effective && old->ca_effective) {
+            md->ca_effective = apr_pstrdup(p, old->ca_effective);
+        }
+        if (!md->ca_account && old->ca_account) {
+            md->ca_account = apr_pstrdup(p, old->ca_account);
+        }
+        
+        /* if everything remains the same, spare the write back */
+        if (!MD_VAL_UPDATE(md, old, state)
+            && md_array_str_eq(md->ca_urls, old->ca_urls, 0)
+            && !MD_SVAL_UPDATE(md, old, ca_proto)
+            && !MD_SVAL_UPDATE(md, old, ca_agreement)
+            && !MD_VAL_UPDATE(md, old, transitive)
+            && md_equal_domains(md, old, 1)
+            && !MD_VAL_UPDATE(md, old, renew_mode)
+            && md_timeslice_eq(md->renew_window, old->renew_window)
+            && md_timeslice_eq(md->warn_window, old->warn_window)
+            && md_pkeys_spec_eq(md->pks, old->pks)
+            && !MD_VAL_UPDATE(md, old, require_https)
+            && !MD_VAL_UPDATE(md, old, must_staple)
+            && md_array_str_eq(md->acme_tls_1_domains, old->acme_tls_1_domains, 0)
+            && !MD_VAL_UPDATE(md, old, stapling)
+            && md_array_str_eq(md->contacts, old->contacts, 0)
+            && md_array_str_eq(md->cert_files, old->cert_files, 0)
+            && md_array_str_eq(md->pkey_files, old->pkey_files, 0)
+            && md_array_str_eq(md->ca_challenges, old->ca_challenges, 0)) {
+            changed = 0;
+        }
+    }
+    if (changed) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, ptemp, "saving md %s", md->name);
+        rv = md_save(reg->store, ptemp, MD_SG_DOMAINS, md, 0);
+    }
+leave:
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, ptemp, "sync MDs, finish done");
+    return rv;
+}
+
+apr_status_t md_reg_remove(md_reg_t *reg, apr_pool_t *p, const char *name, int archive)
+{
+    if (reg->domains_frozen) return APR_EACCES; 
+    return md_store_move(reg->store, p, MD_SG_DOMAINS, MD_SG_ARCHIVE, name, archive);
+}
+
+typedef struct {
+    md_reg_t *reg;
+    apr_pool_t *p;
+    apr_array_header_t *mds;
+} cleanup_challenge_ctx;
+ 
+static apr_status_t cleanup_challenge_inspector(void *baton, const char *dir, const char *name, 
+                                                md_store_vtype_t vtype, void *value, 
+                                                apr_pool_t *ptemp)
+{
+    cleanup_challenge_ctx *ctx = baton;
+    const md_t *md;
+    int i, used;
+    apr_status_t rv;
+    
+    (void)value;
+    (void)vtype;
+    (void)dir;
+    for (used = 0, i = 0; i < ctx->mds->nelts && !used; ++i) {
+        md = APR_ARRAY_IDX(ctx->mds, i, const md_t *);
+        used = !strcmp(name, md->name);
+    }
+    if (!used) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, ptemp, 
+                      "challenges/%s: not in use, purging", name);
+        rv = md_store_purge(ctx->reg->store, ctx->p, MD_SG_CHALLENGES, name);
+        if (APR_SUCCESS != rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, rv, ptemp, 
+                          "challenges/%s: unable to purge", name);
+        }
+    }
+    return APR_SUCCESS;
+}
+
+apr_status_t md_reg_cleanup_challenges(md_reg_t *reg, apr_pool_t *p, apr_pool_t *ptemp, 
+                                       apr_array_header_t *mds)
+{
+    apr_status_t rv;
+    cleanup_challenge_ctx ctx;
+
+    (void)p;
+    ctx.reg = reg;
+    ctx.p = ptemp;
+    ctx.mds = mds;
+    rv = md_store_iter_names(cleanup_challenge_inspector, &ctx, reg->store, ptemp, 
+                             MD_SG_CHALLENGES, "*");
+    return rv;
+}
+
+
+/**************************************************************************************************/
+/* driving */
+
+static apr_status_t run_init(void *baton, apr_pool_t *p, ...)
+{
+    va_list ap;
+    md_reg_t *reg = baton;
+    const md_t *md;
+    md_proto_driver_t *driver, **pdriver;
+    md_result_t *result;
+    apr_table_t *env;
+    const char *s;
+    int preload;
+    
+    (void)p;
+    va_start(ap, p);
+    pdriver = va_arg(ap, md_proto_driver_t **);
+    md = va_arg(ap, const md_t *);
+    preload = va_arg(ap, int);
+    env = va_arg(ap, apr_table_t *);
+    result = va_arg(ap, md_result_t *); 
+    va_end(ap);
+    
+    *pdriver = driver = apr_pcalloc(p, sizeof(*driver));
+
+    driver->p = p;
+    driver->env = env? apr_table_copy(p, env) : apr_table_make(p, 10);
+    driver->reg = reg;
+    driver->store = md_reg_store_get(reg);
+    driver->proxy_url = reg->proxy_url;
+    driver->ca_file = reg->ca_file;
+    driver->md = md;
+    driver->can_http = reg->can_http;
+    driver->can_https = reg->can_https;
+    
+    s = apr_table_get(driver->env, MD_KEY_ACTIVATION_DELAY);
+    if (!s || APR_SUCCESS != md_duration_parse(&driver->activation_delay, s, "d")) {
+        driver->activation_delay = 0;
+    }
+
+    if (!md->ca_proto) {
+        md_result_printf(result, APR_EGENERAL, "CA protocol is not defined"); 
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, 0, p, "md[%s]: %s", md->name, result->detail);
+        goto leave;
+    }
+    
+    driver->proto = apr_hash_get(reg->protos, md->ca_proto, (apr_ssize_t)strlen(md->ca_proto));
+    if (!driver->proto) {
+        md_result_printf(result, APR_EGENERAL, "Unknown CA protocol '%s'", md->ca_proto); 
+        goto leave;
+    }
+    
+    if (preload) {
+        result->status = driver->proto->init_preload(driver, result);
+    }
+    else {
+        result->status = driver->proto->init(driver, result);
+    }
+
+leave:
+    if (APR_SUCCESS != result->status) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_WARNING, result->status, p, "md[%s]: %s", md->name, 
+                      result->detail? result->detail : "<see error log for details>");
+    }
+    else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, "%s: init done", md->name);
+    }
+    return result->status;
+}
+
+static apr_status_t run_test_init(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    const md_t *md;
+    apr_table_t *env;
+    md_result_t *result;
+    md_proto_driver_t *driver;
+    
+    (void)p;
+    md = va_arg(ap, const md_t *);
+    env = va_arg(ap, apr_table_t *);
+    result = va_arg(ap, md_result_t *); 
+
+    return run_init(baton, ptemp, &driver, md, 0, env, result, NULL);
+}
+
+apr_status_t md_reg_test_init(md_reg_t *reg, const md_t *md, struct apr_table_t *env, 
+                              md_result_t *result, apr_pool_t *p)
+{
+    return md_util_pool_vdo(run_test_init, reg, p, md, env, result, NULL);
+}
+
+static apr_status_t run_renew(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_reg_t *reg = baton;
+    const md_t *md;
+    int reset, attempt;
+    md_proto_driver_t *driver;
+    apr_table_t *env;
+    apr_status_t rv;
+    md_result_t *result;
+    
+    (void)p;
+    md = va_arg(ap, const md_t *);
+    env = va_arg(ap, apr_table_t *);
+    reset = va_arg(ap, int); 
+    attempt = va_arg(ap, int);
+    result = va_arg(ap, md_result_t *);
+
+    rv = run_init(reg, ptemp, &driver, md, 0, env, result, NULL);
+    if (APR_SUCCESS == rv) { 
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, ptemp, "%s: run staging", md->name);
+        driver->reset = reset;
+        driver->attempt = attempt;
+        driver->retry_failover = reg->retry_failover;
+        rv = driver->proto->renew(driver, result);
+    }
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, ptemp, "%s: staging done", md->name);
+    return rv;
+}
+
+apr_status_t md_reg_renew(md_reg_t *reg, const md_t *md, apr_table_t *env, 
+                          int reset, int attempt,
+                          md_result_t *result, apr_pool_t *p)
+{
+    return md_util_pool_vdo(run_renew, reg, p, md, env, reset, attempt, result, NULL);
+}
+
+static apr_status_t run_load_staging(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_reg_t *reg = baton;
+    const md_t *md;
+    md_proto_driver_t *driver;
+    md_result_t *result;
+    apr_table_t *env;
+    md_job_t *job;
+    apr_status_t rv;
+    
+    /* For the MD,  check if something is in the STAGING area. If none is there, 
+     * return that status. Otherwise ask the protocol driver to preload it into
+     * a new, temporary area. 
+     * If that succeeds, we move the TEMP area over the DOMAINS (causing the 
+     * existing one go to ARCHIVE).
+     * Finally, we clean up the data from CHALLENGES and STAGING.
+     */
+    md = va_arg(ap, const md_t*);
+    env =  va_arg(ap, apr_table_t*);
+    result =  va_arg(ap, md_result_t*);
+    
+    if (APR_STATUS_IS_ENOENT(rv = md_load(reg->store, MD_SG_STAGING, md->name, NULL, ptemp))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, ptemp, "%s: nothing staged", md->name);
+        goto out;
+    }
+    
+    rv = run_init(baton, ptemp, &driver, md, 1, env, result, NULL);
+    if (APR_SUCCESS != rv) goto out;
+    
+    apr_hash_set(reg->certs, md->name, (apr_ssize_t)strlen(md->name), NULL);
+    md_result_activity_setn(result, "preloading staged to tmp");
+    rv = driver->proto->preload(driver, MD_SG_TMP, result);
+    if (APR_SUCCESS != rv) goto out;
+
+    /* If we had a job saved in STAGING, copy it over too */
+    job = md_reg_job_make(reg, md->name, ptemp);
+    if (APR_SUCCESS == md_job_load(job)) {
+        md_job_set_group(job, MD_SG_TMP);
+        md_job_save(job, NULL, ptemp);
+    }
+    
+    /* swap */
+    md_result_activity_setn(result, "moving tmp to become new domains");
+    rv = md_store_move(reg->store, p, MD_SG_TMP, MD_SG_DOMAINS, md->name, 1);
+    if (APR_SUCCESS != rv) {
+        md_result_set(result, rv, NULL);
+        goto out;
+    }
+    
+    md_store_purge(reg->store, p, MD_SG_STAGING, md->name);
+    md_store_purge(reg->store, p, MD_SG_CHALLENGES, md->name);
+    md_result_set(result, APR_SUCCESS, "new certificate successfully saved in domains");
+    md_event_holler("installed", md->name, job, result, ptemp);
+    if (job->dirty) md_job_save(job, result, ptemp);
+    
+out:
+    if (!APR_STATUS_IS_ENOENT(rv)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, ptemp, "%s: load done", md->name);
+    }
+    return rv;
+}
+
+apr_status_t md_reg_load_staging(md_reg_t *reg, const md_t *md, apr_table_t *env, 
+                                 md_result_t *result, apr_pool_t *p)
+{
+    if (reg->domains_frozen) return APR_EACCES;
+    return md_util_pool_vdo(run_load_staging, reg, p, md, env, result, NULL);
+}
+
+apr_status_t md_reg_load_stagings(md_reg_t *reg, apr_array_header_t *mds,
+                                  apr_table_t *env, apr_pool_t *p)
+{
+    apr_status_t rv = APR_SUCCESS;
+    md_t *md;
+    md_result_t *result;
+    int i;
+
+    for (i = 0; i < mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(mds, i, md_t *);
+        result = md_result_md_make(p, md->name);
+        rv = md_reg_load_staging(reg, md, env, result, p);
+        if (APR_SUCCESS == rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_INFO, rv, p, APLOGNO(10068)
+                          "%s: staged set activated", md->name);
+        }
+        else if (!APR_STATUS_IS_ENOENT(rv)) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, APLOGNO(10069)
+                          "%s: error loading staged set", md->name);
+        }
+    }
+
+    return rv;
+}
+
+apr_status_t md_reg_lock_global(md_reg_t *reg, apr_pool_t *p)
+{
+    apr_status_t rv = APR_SUCCESS;
+
+    if (reg->use_store_locks) {
+        rv = md_store_lock_global(reg->store, p, reg->lock_wait_timeout);
+        if (APR_SUCCESS != rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p,
+                          "unable to acquire global store lock");
+        }
+    }
+    return rv;
+}
+
+void md_reg_unlock_global(md_reg_t *reg, apr_pool_t *p)
+{
+    if (reg->use_store_locks) {
+        md_store_unlock_global(reg->store, p);
+    }
+}
+
+apr_status_t md_reg_freeze_domains(md_reg_t *reg, apr_array_header_t *mds)
+{
+    apr_status_t rv = APR_SUCCESS;
+    md_t *md;
+    const md_pubcert_t *pubcert;
+    int i, j;
+    
+    assert(!reg->domains_frozen);
+    /* prefill the certs cache for all mds */
+    for (i = 0; i < mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(mds, i, md_t*);
+        for (j = 0; j < md_cert_count(md); ++j) {
+            rv = md_reg_get_pubcert(&pubcert, reg, md, i, reg->p);
+            if (APR_SUCCESS != rv && !APR_STATUS_IS_ENOENT(rv)) goto leave;
+        }
+    }
+    reg->domains_frozen = 1;
+leave:
+    return rv;
+}
+
+void md_reg_set_renew_window_default(md_reg_t *reg, md_timeslice_t *renew_window)
+{
+    *reg->renew_window = *renew_window;
+}
+
+void md_reg_set_warn_window_default(md_reg_t *reg, md_timeslice_t *warn_window)
+{
+    *reg->warn_window = *warn_window;
+}
+
+md_job_t *md_reg_job_make(md_reg_t *reg, const char *mdomain, apr_pool_t *p)
+{
+    return md_job_make(p, reg->store, MD_SG_STAGING, mdomain, reg->min_delay);
+}
diff --git a/modules/md/md_reg.h b/modules/md/md_reg.h
new file mode 100644
index 0000000..58ee16a
--- /dev/null
+++ b/modules/md/md_reg.h
@@ -0,0 +1,313 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_reg_h
+#define mod_md_md_reg_h
+
+struct apr_hash_t;
+struct apr_array_header_t;
+struct md_pkey_t;
+struct md_cert_t;
+struct md_result_t;
+struct md_pkey_spec_t;
+
+#include "md_store.h"
+
+/**
+ * A registry for managed domains with a md_store_t as persistence.
+ *
+ */
+typedef struct md_reg_t md_reg_t;
+
+/**
+ * Create the MD registry, using the pool and store.
+ * @param preg on APR_SUCCESS, the create md_reg_t
+ * @param pm memory pool to use for creation
+ * @param store the store to base on
+ * @param proxy_url optional URL of a proxy to use for requests
+ * @param ca_file  optioinal CA trust anchor file to use
+ * @param min_delay minimum delay between renewal attempts for a domain
+ * @param retry_failover numer of failed renewals attempt to fail over to alternate ACME ca
+ */
+apr_status_t md_reg_create(md_reg_t **preg, apr_pool_t *pm, md_store_t *store,
+                           const char *proxy_url, const char *ca_file,
+                           apr_time_t min_delay, int retry_failover,
+                           int use_store_locks, apr_time_t lock_wait_timeout);
+
+md_store_t *md_reg_store_get(md_reg_t *reg);
+
+apr_status_t md_reg_set_props(md_reg_t *reg, apr_pool_t *p, int can_http, int can_https);
+
+/**
+ * Add a new md to the registry. This will check the name for uniqueness and
+ * that domain names do not overlap with already existing mds.
+ */
+apr_status_t md_reg_add(md_reg_t *reg, md_t *md, apr_pool_t *p);
+
+/**
+ * Find the md, if any, that contains the given domain name. 
+ * NULL if none found.
+ */
+md_t *md_reg_find(md_reg_t *reg, const char *domain, apr_pool_t *p);
+
+/**
+ * Find one md, which domain names overlap with the given md and that has a different
+ * name. There may be more than one existing md that overlaps. It is not defined
+ * which one will be returned. 
+ */
+md_t *md_reg_find_overlap(md_reg_t *reg, const md_t *md, const char **pdomain, apr_pool_t *p);
+
+/**
+ * Get the md with the given unique name. NULL if it does not exist.
+ * Will update the md->state.
+ */
+md_t *md_reg_get(md_reg_t *reg, const char *name, apr_pool_t *p);
+
+/**
+ * Callback invoked for every md in the registry. If 0 is returned, iteration stops.
+ */
+typedef int md_reg_do_cb(void *baton, md_reg_t *reg, md_t *md);
+
+/**
+ * Invoke callback for all mds in this registry. Order is not guaranteed.
+ * If the callback returns 0, iteration stops. Returns 0 if iteration was
+ * aborted.
+ */
+int md_reg_do(md_reg_do_cb *cb, void *baton, md_reg_t *reg, apr_pool_t *p);
+
+/**
+ * Bitmask for fields that are updated.
+ */
+#define MD_UPD_DOMAINS       0x00001
+#define MD_UPD_CA_URL        0x00002
+#define MD_UPD_CA_PROTO      0x00004
+#define MD_UPD_CA_ACCOUNT    0x00008
+#define MD_UPD_CONTACTS      0x00010
+#define MD_UPD_AGREEMENT     0x00020
+#define MD_UPD_DRIVE_MODE    0x00080
+#define MD_UPD_RENEW_WINDOW  0x00100
+#define MD_UPD_CA_CHALLENGES 0x00200
+#define MD_UPD_PKEY_SPEC     0x00400
+#define MD_UPD_REQUIRE_HTTPS 0x00800
+#define MD_UPD_TRANSITIVE    0x01000
+#define MD_UPD_MUST_STAPLE   0x02000
+#define MD_UPD_PROTO         0x04000
+#define MD_UPD_WARN_WINDOW   0x08000
+#define MD_UPD_STAPLING      0x10000
+#define MD_UPD_ALL           0x7FFFFFFF
+
+/**
+ * Update the given fields for the managed domain. Take the new
+ * values from the given md, all other values remain unchanged.
+ */
+apr_status_t md_reg_update(md_reg_t *reg, apr_pool_t *p, 
+                           const char *name, const md_t *md, 
+                           int fields, int check_consistency);
+
+/**
+ * Get the chain of public certificates of the managed domain md, starting with the cert
+ * of the domain and going up the issuers. Returns APR_ENOENT when not available. 
+ */
+apr_status_t md_reg_get_pubcert(const md_pubcert_t **ppubcert, md_reg_t *reg, 
+                                const md_t *md, int i, apr_pool_t *p);
+
+/**
+ * Get the filenames of private key and pubcert of the MD - if they exist.
+ * @return APR_ENOENT if one or both do not exist.
+ */
+apr_status_t md_reg_get_cred_files(const char **pkeyfile, const char **pcertfile,
+                                   md_reg_t *reg, md_store_group_t group, 
+                                   const md_t *md, struct md_pkey_spec_t *spec, apr_pool_t *p);
+
+/**
+ * Synchronize the given master mds with the store.
+ */
+apr_status_t md_reg_sync_start(md_reg_t *reg, apr_array_header_t *master_mds, apr_pool_t *p);
+
+/**
+ * Re-compute the state of the MD, given current store contents.
+ */
+apr_status_t md_reg_sync_finish(md_reg_t *reg, md_t *md, apr_pool_t *p, apr_pool_t *ptemp);
+
+
+apr_status_t md_reg_remove(md_reg_t *reg, apr_pool_t *p, const char *name, int archive);
+
+/**
+ * Delete the account from the local store.
+ */
+apr_status_t md_reg_delete_acct(md_reg_t *reg, apr_pool_t *p, const char *acct_id);
+
+
+/**
+ * Cleanup any challenges that are no longer in use.
+ * 
+ * @param reg   the registry
+ * @param p     pool for permanent storage
+ * @param ptemp pool for temporary storage
+ * @param mds   the list of configured MDs
+ */
+apr_status_t md_reg_cleanup_challenges(md_reg_t *reg, apr_pool_t *p, apr_pool_t *ptemp, 
+                                       apr_array_header_t *mds);
+
+/**
+ * Mark all information from group MD_SG_DOMAINS as readonly, deny future modifications 
+ * (MD_SG_STAGING and MD_SG_CHALLENGES remain writeable). For the given MDs, cache
+ * the public information (MDs themselves and their pubcerts or lack of).
+ */
+apr_status_t md_reg_freeze_domains(md_reg_t *reg, apr_array_header_t *mds);
+
+/**
+ * Return if the certificate of the MD should be renewed. This includes reaching
+ * the renewal window of an otherwise valid certificate. It return also !0 iff
+ * no certificate has been obtained yet.
+ */
+int md_reg_should_renew(md_reg_t *reg, const md_t *md, apr_pool_t *p);
+
+/**
+ * Return the timestamp when the certificate should be renewed. A value of 0
+ * indicates that that renewal is not configured (see renew_mode).
+ */
+apr_time_t md_reg_renew_at(md_reg_t *reg, const md_t *md, apr_pool_t *p);
+
+/**
+ * Return the timestamp up to which *all* certificates for the MD can be used.
+ * A value of 0 indicates that there is no certificate.
+ */
+apr_time_t md_reg_valid_until(md_reg_t *reg, const md_t *md, apr_pool_t *p);
+
+/**
+ * Return if a warning should be issued about the certificate expiration. 
+ * This applies the configured warn window to the remaining lifetime of the 
+ * current certiciate. If no certificate is present, this returns 0.
+ */
+int md_reg_should_warn(md_reg_t *reg, const md_t *md, apr_pool_t *p);
+
+/**************************************************************************************************/
+/* protocol drivers */
+
+typedef struct md_proto_t md_proto_t;
+
+typedef struct md_proto_driver_t md_proto_driver_t;
+
+/** 
+ * Operating environment for a protocol driver. This is valid only for the
+ * duration of one run (init + renew, init + preload).
+ */
+struct md_proto_driver_t {
+    const md_proto_t *proto;
+    apr_pool_t *p;
+    void *baton;
+    struct apr_table_t *env;
+
+    md_reg_t *reg;
+    md_store_t *store;
+    const char *proxy_url;
+    const char *ca_file;
+    const md_t *md;
+
+    int can_http;
+    int can_https;
+    int reset;
+    int attempt;
+    int retry_failover;
+    apr_interval_time_t activation_delay;
+};
+
+typedef apr_status_t md_proto_init_cb(md_proto_driver_t *driver, struct md_result_t *result);
+typedef apr_status_t md_proto_renew_cb(md_proto_driver_t *driver, struct md_result_t *result);
+typedef apr_status_t md_proto_init_preload_cb(md_proto_driver_t *driver, struct md_result_t *result);
+typedef apr_status_t md_proto_preload_cb(md_proto_driver_t *driver, 
+                                         md_store_group_t group, struct md_result_t *result);
+typedef apr_status_t md_proto_complete_md_cb(md_t *md, apr_pool_t *p);
+
+struct md_proto_t {
+    const char *protocol;
+    md_proto_init_cb *init;
+    md_proto_renew_cb *renew;
+    md_proto_init_preload_cb *init_preload;
+    md_proto_preload_cb *preload;
+    md_proto_complete_md_cb *complete_md;
+};
+
+/**
+ * Run a test initialization of the renew protocol for the given MD. This verifies
+ * basic parameter settings and is expected to return a description of encountered
+ * problems in <pmessage> when != APR_SUCCESS.
+ * A message return is allocated fromt the given pool.
+ */
+apr_status_t md_reg_test_init(md_reg_t *reg, const md_t *md, struct apr_table_t *env, 
+                              struct md_result_t *result, apr_pool_t *p);
+
+/**
+ * Obtain new credentials for the given managed domain in STAGING.
+ * @param reg the registry instance
+ * @param md the mdomain to renew
+ * @param env global environment of settings
+ * @param reset != 0 if any previous, partial information should be wiped
+ * @param attempt the number of attempts made this far (for this md)
+ * @param result for reporting results of the renewal
+ * @param p the memory pool to use
+ * @return APR_SUCCESS if new credentials have been staged successfully
+ */
+apr_status_t md_reg_renew(md_reg_t *reg, const md_t *md, 
+                          struct apr_table_t *env, int reset, int attempt,
+                          struct md_result_t *result, apr_pool_t *p);
+
+/**
+ * Load a new set of credentials for the managed domain from STAGING - if it exists. 
+ * This will archive any existing credential data and make the staged set the new one
+ * in DOMAINS.
+ * If staging is incomplete or missing, the load will fail and all credentials remain
+ * as they are.
+ *
+ * @return APR_SUCCESS on loading new data, APR_ENOENT when nothing is staged, error otherwise.
+ */
+apr_status_t md_reg_load_staging(md_reg_t *reg, const md_t *md, struct apr_table_t *env, 
+                                 struct md_result_t *result, apr_pool_t *p);
+
+/**
+ * Check given MDomains for new data in staging areas and, if it exists, load
+ * the new credentials. On encountering errors, leave the credentails as
+ * they are.
+ */
+apr_status_t md_reg_load_stagings(md_reg_t *reg, apr_array_header_t *mds,
+                                  apr_table_t *env, apr_pool_t *p);
+
+void md_reg_set_renew_window_default(md_reg_t *reg, md_timeslice_t *renew_window);
+void md_reg_set_warn_window_default(md_reg_t *reg, md_timeslice_t *warn_window);
+
+struct md_job_t *md_reg_job_make(md_reg_t *reg, const char *mdomain, apr_pool_t *p);
+
+/**
+ * Acquire a cooperative, global lock on registry modifications. Will
+ * do nothing if locking is not configured.
+ *
+ * This will only prevent other children/processes/cluster nodes from
+ * doing the same and does not protect individual store functions from
+ * being called without it.
+ * @param reg the registy
+ * @param p memory pool to use
+ * @param max_wait maximum time to wait in order to acquire
+ * @return APR_SUCCESS when lock was obtained
+ */
+apr_status_t md_reg_lock_global(md_reg_t *reg, apr_pool_t *p);
+
+/**
+ * Realease the global registry lock. Will do nothing if there is no lock.
+ */
+void md_reg_unlock_global(md_reg_t *reg, apr_pool_t *p);
+
+#endif /* mod_md_md_reg_h */
diff --git a/modules/md/md_result.c b/modules/md/md_result.c
new file mode 100644
index 0000000..64a2f70
--- /dev/null
+++ b/modules/md/md_result.c
@@ -0,0 +1,285 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_date.h>
+#include <apr_time.h>
+#include <apr_strings.h>
+
+#include "md.h"
+#include "md_json.h"
+#include "md_log.h"
+#include "md_result.h"
+
+static const char *dup_trim(apr_pool_t *p, const char *s)
+{
+    char *d = apr_pstrdup(p, s);
+    if (d) apr_collapse_spaces(d, d);
+    return d;
+}
+
+md_result_t *md_result_make(apr_pool_t *p, apr_status_t status)
+{
+    md_result_t *result;
+    
+    result = apr_pcalloc(p, sizeof(*result));
+    result->p = p;
+    result->md_name = MD_OTHER;
+    result->status = status;
+    return result;
+}
+
+md_result_t *md_result_md_make(apr_pool_t *p, const char *md_name)
+{
+    md_result_t *result = md_result_make(p, APR_SUCCESS);
+    result->md_name = md_name;
+    return result;
+}
+
+void md_result_reset(md_result_t *result)
+{
+    apr_pool_t *p = result->p;
+    memset(result, 0, sizeof(*result));
+    result->p = p;
+}
+
+static void on_change(md_result_t *result)
+{
+    if (result->on_change) result->on_change(result, result->on_change_data);
+}
+
+void md_result_activity_set(md_result_t *result, const char *activity)
+{
+    md_result_activity_setn(result, activity? apr_pstrdup(result->p, activity) : NULL);
+}
+
+void md_result_activity_setn(md_result_t *result, const char *activity)
+{
+    result->activity = activity;
+    result->problem = result->detail = NULL;
+    result->subproblems = NULL;
+    on_change(result);
+}
+
+void md_result_activity_printf(md_result_t *result, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    md_result_activity_setn(result, apr_pvsprintf(result->p, fmt, ap));
+    va_end(ap);
+}
+
+void md_result_set(md_result_t *result, apr_status_t status, const char *detail)
+{
+    result->status = status;
+    result->problem = NULL;
+    result->detail = detail? apr_pstrdup(result->p, detail) : NULL;
+    result->subproblems = NULL;
+    on_change(result);
+}
+
+void md_result_problem_set(md_result_t *result, apr_status_t status,
+                           const char *problem, const char *detail, 
+                           const md_json_t *subproblems)
+{
+    result->status = status;
+    result->problem = dup_trim(result->p, problem);
+    result->detail = apr_pstrdup(result->p, detail);
+    result->subproblems = subproblems? md_json_clone(result->p, subproblems) : NULL;
+    on_change(result);
+}
+
+void md_result_problem_printf(md_result_t *result, apr_status_t status,
+                              const char *problem, const char *fmt, ...)
+{
+    va_list ap;
+
+    result->status = status;
+    result->problem = dup_trim(result->p, problem);
+
+    va_start(ap, fmt);
+    result->detail = apr_pvsprintf(result->p, fmt, ap);
+    va_end(ap);
+    result->subproblems = NULL;
+    on_change(result);
+}
+
+void md_result_printf(md_result_t *result, apr_status_t status, const char *fmt, ...)
+{
+    va_list ap;
+
+    result->status = status;
+    va_start(ap, fmt);
+    result->detail = apr_pvsprintf(result->p, fmt, ap);
+    va_end(ap);
+    result->subproblems = NULL;
+    on_change(result);
+}
+
+void md_result_delay_set(md_result_t *result, apr_time_t ready_at)
+{
+    result->ready_at = ready_at;
+    on_change(result);
+}
+
+md_result_t*md_result_from_json(const struct md_json_t *json, apr_pool_t *p)
+{
+    md_result_t *result;
+    const char *s;
+    
+    result = md_result_make(p, APR_SUCCESS);
+    result->status = (int)md_json_getl(json, MD_KEY_STATUS, NULL);
+    result->problem = md_json_dups(p, json, MD_KEY_PROBLEM, NULL);
+    result->detail = md_json_dups(p, json, MD_KEY_DETAIL, NULL);
+    result->activity = md_json_dups(p, json, MD_KEY_ACTIVITY, NULL);
+    s = md_json_dups(p, json, MD_KEY_VALID_FROM, NULL);
+    if (s && *s) result->ready_at = apr_date_parse_rfc(s);
+    result->subproblems = md_json_dupj(p, json, MD_KEY_SUBPROBLEMS, NULL);
+    return result;
+}
+
+struct md_json_t *md_result_to_json(const md_result_t *result, apr_pool_t *p)
+{
+    md_json_t *json;
+    char ts[APR_RFC822_DATE_LEN];
+   
+    json = md_json_create(p);
+    md_json_setl(result->status, json, MD_KEY_STATUS, NULL);
+    if (result->status > 0) {
+        char buffer[HUGE_STRING_LEN];
+        apr_strerror(result->status, buffer, sizeof(buffer));
+        md_json_sets(buffer, json, "status-description", NULL);
+    }
+    if (result->problem) md_json_sets(result->problem, json, MD_KEY_PROBLEM, NULL);
+    if (result->detail) md_json_sets(result->detail, json, MD_KEY_DETAIL, NULL);
+    if (result->activity) md_json_sets(result->activity, json, MD_KEY_ACTIVITY, NULL);
+    if (result->ready_at > 0) {
+        apr_rfc822_date(ts, result->ready_at);
+        md_json_sets(ts, json, MD_KEY_VALID_FROM, NULL);
+    }
+    if (result->subproblems) {
+        md_json_setj(result->subproblems, json, MD_KEY_SUBPROBLEMS, NULL);
+    }
+    return json;
+}
+
+static int str_cmp(const char *s1, const char *s2)
+{
+    if (s1 == s2) return 0;
+    if (!s1) return -1;
+    if (!s2) return 1;
+    return strcmp(s1, s2);
+}
+
+int md_result_cmp(const md_result_t *r1, const md_result_t *r2)
+{
+    int n;
+    if (r1 == r2) return 0;
+    if (!r1) return -1;
+    if (!r2) return 1;
+    if ((n = r1->status - r2->status)) return n;
+    if ((n = str_cmp(r1->problem, r2->problem))) return n;
+    if ((n = str_cmp(r1->detail, r2->detail))) return n;
+    if ((n = str_cmp(r1->activity, r2->activity))) return n;
+    return (int)(r1->ready_at - r2->ready_at);
+}
+
+void md_result_assign(md_result_t *dest, const md_result_t *src)
+{
+   dest->status = src->status;
+   dest->problem = src->problem;
+   dest->detail = src->detail;
+   dest->activity = src->activity;
+   dest->ready_at = src->ready_at;
+   dest->subproblems = src->subproblems;
+}
+
+void md_result_dup(md_result_t *dest, const md_result_t *src)
+{
+   dest->status = src->status;
+   dest->problem = src->problem? dup_trim(dest->p, src->problem) : NULL; 
+   dest->detail = src->detail? apr_pstrdup(dest->p, src->detail) : NULL; 
+   dest->activity = src->activity? apr_pstrdup(dest->p, src->activity) : NULL; 
+   dest->ready_at = src->ready_at;
+   dest->subproblems = src->subproblems? md_json_clone(dest->p, src->subproblems) : NULL;
+   on_change(dest);
+}
+
+void md_result_log(md_result_t *result, unsigned int level)
+{
+    if (md_log_is_level(result->p, (md_log_level_t)level)) {
+        const char *sep = "";
+        const char *msg = "";
+        
+        if (result->md_name) {
+            msg = apr_psprintf(result->p, "md[%s]", result->md_name);
+            sep = " ";
+        }
+        if (result->activity) {
+            msg = apr_psprintf(result->p, "%s%swhile[%s]", msg, sep, result->activity);
+            sep = " ";
+        }
+        if (result->problem) {
+            msg = apr_psprintf(result->p, "%s%sproblem[%s]", msg, sep, result->problem);
+            sep = " ";
+        }
+        if (result->detail) {
+            msg = apr_psprintf(result->p, "%s%sdetail[%s]", msg, sep, result->detail);
+            sep = " ";
+        }
+        if (result->subproblems) {
+            msg = apr_psprintf(result->p, "%s%ssubproblems[%s]", msg, sep, 
+                md_json_writep(result->subproblems, result->p, MD_JSON_FMT_COMPACT));
+            sep = " ";
+        }
+        md_log_perror(MD_LOG_MARK, (md_log_level_t)level, result->status, result->p, "%s", msg);
+    }
+}
+
+void md_result_on_change(md_result_t *result, md_result_change_cb *cb, void *data)
+{
+    result->on_change = cb;
+    result->on_change_data = data;
+}
+
+apr_status_t md_result_raise(md_result_t *result, const char *event, apr_pool_t *p)
+{
+    if (result->on_raise) return result->on_raise(result, result->on_raise_data, event, p);
+    return APR_SUCCESS;
+}
+
+void md_result_holler(md_result_t *result, const char *event, apr_pool_t *p)
+{
+    if (result->on_holler) result->on_holler(result, result->on_holler_data, event, p);
+}
+
+void md_result_on_raise(md_result_t *result, md_result_raise_cb *cb, void *data)
+{
+    result->on_raise = cb;
+    result->on_raise_data = data;
+}
+
+void md_result_on_holler(md_result_t *result, md_result_holler_cb *cb, void *data)
+{
+    result->on_holler = cb;
+    result->on_holler_data = data;
+}
diff --git a/modules/md/md_result.h b/modules/md/md_result.h
new file mode 100644
index 0000000..e83bdd2
--- /dev/null
+++ b/modules/md/md_result.h
@@ -0,0 +1,87 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_result_h
+#define mod_md_md_result_h
+
+struct md_json_t;
+struct md_t;
+
+typedef struct md_result_t md_result_t;
+
+typedef void md_result_change_cb(md_result_t *result, void *data);
+typedef apr_status_t md_result_raise_cb(md_result_t *result, void *data, const char *event, apr_pool_t *p);
+typedef void md_result_holler_cb(md_result_t *result, void *data, const char *event, apr_pool_t *p);
+
+struct md_result_t {
+    apr_pool_t *p;
+    const char *md_name;
+    apr_status_t status;
+    const char *problem;
+    const char *detail;
+    const struct md_json_t *subproblems;
+    const char *activity;
+    apr_time_t ready_at;
+    md_result_change_cb *on_change;
+    void *on_change_data;
+    md_result_raise_cb *on_raise;
+    void *on_raise_data;
+    md_result_holler_cb *on_holler;
+    void *on_holler_data;
+};
+
+md_result_t *md_result_make(apr_pool_t *p, apr_status_t status);
+md_result_t *md_result_md_make(apr_pool_t *p, const char *md_name);
+void md_result_reset(md_result_t *result);
+
+void md_result_activity_set(md_result_t *result, const char *activity);
+void md_result_activity_setn(md_result_t *result, const char *activity);
+void md_result_activity_printf(md_result_t *result, const char *fmt, ...);
+
+void md_result_set(md_result_t *result, apr_status_t status, const char *detail);
+void md_result_problem_set(md_result_t *result, apr_status_t status, 
+                           const char *problem, const char *detail, 
+                           const struct md_json_t *subproblems);
+void md_result_problem_printf(md_result_t *result, apr_status_t status,
+                              const char *problem, const char *fmt, ...);
+
+#define MD_RESULT_LOG_ID(logno)       "urn:org:apache:httpd:log:"logno
+
+void md_result_printf(md_result_t *result, apr_status_t status, const char *fmt, ...);
+
+void md_result_delay_set(md_result_t *result, apr_time_t ready_at);
+
+md_result_t*md_result_from_json(const struct md_json_t *json, apr_pool_t *p);
+struct md_json_t *md_result_to_json(const md_result_t *result, apr_pool_t *p);
+
+int md_result_cmp(const md_result_t *r1, const md_result_t *r2);
+
+void md_result_assign(md_result_t *dest, const md_result_t *src);
+void md_result_dup(md_result_t *dest, const md_result_t *src);
+
+void md_result_log(md_result_t *result, unsigned int level);
+
+void md_result_on_change(md_result_t *result, md_result_change_cb *cb, void *data);
+
+/* events in the context of a result genesis */
+
+apr_status_t md_result_raise(md_result_t *result, const char *event, apr_pool_t *p);
+void md_result_holler(md_result_t *result, const char *event, apr_pool_t *p);
+
+void md_result_on_raise(md_result_t *result, md_result_raise_cb *cb, void *data);
+void md_result_on_holler(md_result_t *result, md_result_holler_cb *cb, void *data);
+
+#endif /* mod_md_md_result_h */
diff --git a/modules/md/md_status.c b/modules/md/md_status.c
new file mode 100644
index 0000000..936c653
--- /dev/null
+++ b/modules/md/md_status.c
@@ -0,0 +1,653 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_tables.h>
+#include <apr_time.h>
+#include <apr_date.h>
+
+#include "md_json.h"
+#include "md.h"
+#include "md_acme.h"
+#include "md_crypt.h"
+#include "md_event.h"
+#include "md_log.h"
+#include "md_ocsp.h"
+#include "md_store.h"
+#include "md_result.h"
+#include "md_reg.h"
+#include "md_util.h"
+#include "md_status.h"
+
+#define MD_STATUS_WITH_SCTS     0
+
+/**************************************************************************************************/
+/* certificate status information */
+
+static apr_status_t status_get_cert_json(md_json_t **pjson, const md_cert_t *cert, apr_pool_t *p)
+{
+    const char *finger;
+    apr_status_t rv = APR_SUCCESS;
+    md_timeperiod_t valid;
+    md_json_t *json;
+    
+    json = md_json_create(p);
+    valid.start = md_cert_get_not_before(cert);
+    valid.end = md_cert_get_not_after(cert);
+    md_json_set_timeperiod(&valid, json, MD_KEY_VALID, NULL);
+    md_json_sets(md_cert_get_serial_number(cert, p), json, MD_KEY_SERIAL, NULL);
+    if (APR_SUCCESS != (rv = md_cert_to_sha256_fingerprint(&finger, cert, p))) goto leave;
+    md_json_sets(finger, json, MD_KEY_SHA256_FINGERPRINT, NULL);
+
+#if MD_STATUS_WITH_SCTS
+    do {
+        apr_array_header_t *scts;
+        const char *hex;
+        const md_sct *sct;
+        md_json_t *sctj;
+        int i;
+        
+        scts = apr_array_make(p, 5, sizeof(const md_sct*));
+        if (APR_SUCCESS == md_cert_get_ct_scts(scts, p, cert)) {
+            for (i = 0; i < scts->nelts; ++i) {
+                sct = APR_ARRAY_IDX(scts, i, const md_sct*);
+                sctj = md_json_create(p);
+                
+                apr_rfc822_date(ts, sct->timestamp);
+                md_json_sets(ts, sctj, "signed", NULL);
+                md_json_setl(sct->version, sctj, MD_KEY_VERSION, NULL);
+                md_data_to_hex(&hex, 0, p, sct->logid);
+                md_json_sets(hex, sctj, "logid", NULL);
+                md_data_to_hex(&hex, 0, p, sct->signature);
+                md_json_sets(hex, sctj, "signature", NULL);
+                md_json_sets(md_nid_get_sname(sct->signature_type_nid), sctj, "signature-type", NULL);
+                md_json_addj(sctj, json, "scts", NULL);
+            }
+        }
+    while (0);
+#endif
+leave:
+    *pjson = (APR_SUCCESS == rv)? json : NULL;
+    return rv;
+}
+
+static apr_status_t job_loadj(md_json_t **pjson, md_store_group_t group, const char *name,
+                              struct md_reg_t *reg, int with_log, apr_pool_t *p)
+{
+    apr_status_t rv;
+
+    md_store_t *store = md_reg_store_get(reg);
+    rv = md_store_load_json(store, group, name, MD_FN_JOB, pjson, p);
+    if (APR_SUCCESS == rv && !with_log) md_json_del(*pjson, MD_KEY_LOG, NULL);
+    return rv;
+}
+
+static apr_status_t status_get_cert_json_ex(
+    md_json_t **pjson,
+    const md_cert_t *cert,
+    const md_t *md,
+    md_reg_t *reg,
+    md_ocsp_reg_t *ocsp,
+    int with_logs,
+    apr_pool_t *p)
+{
+    md_json_t *certj, *jobj;
+    md_timeperiod_t ocsp_valid;
+    md_ocsp_cert_stat_t cert_stat;
+    apr_status_t rv;
+
+    if (APR_SUCCESS != (rv = status_get_cert_json(&certj, cert, p))) goto leave;
+    if (md->stapling && ocsp) {
+        rv = md_ocsp_get_meta(&cert_stat, &ocsp_valid, ocsp, cert, p, md);
+        if (APR_SUCCESS == rv) {
+            md_json_sets(md_ocsp_cert_stat_name(cert_stat), certj, MD_KEY_OCSP, MD_KEY_STATUS, NULL);
+            md_json_set_timeperiod(&ocsp_valid, certj, MD_KEY_OCSP, MD_KEY_VALID, NULL);
+        }
+        else if (!APR_STATUS_IS_ENOENT(rv)) goto leave;
+        rv = APR_SUCCESS;
+        if (APR_SUCCESS == job_loadj(&jobj, MD_SG_OCSP, md->name, reg, with_logs, p)) {
+            md_json_setj(jobj, certj, MD_KEY_OCSP, MD_KEY_RENEWAL, NULL);
+        }
+    }
+leave:
+    *pjson = (APR_SUCCESS == rv)? certj : NULL;
+    return rv;
+}
+
+static int get_cert_count(const md_t *md, int from_staging)
+{
+    if (!from_staging && md->cert_files && md->cert_files->nelts) {
+        return md->cert_files->nelts;
+    }
+    return md_pkeys_spec_count(md->pks);
+}
+
+static const char *get_cert_name(const md_t *md, int i, int from_staging, apr_pool_t *p)
+{
+    if (!from_staging && md->cert_files && md->cert_files->nelts) {
+        /* static files configured, not from staging, used index names */
+        return apr_psprintf(p, "%d", i);
+    }
+    return md_pkey_spec_name(md_pkeys_spec_get(md->pks, i));
+}
+
+static apr_status_t status_get_certs_json(md_json_t **pjson, apr_array_header_t *certs,
+                                          int from_staging,
+                                          const md_t *md, md_reg_t *reg,  
+                                          md_ocsp_reg_t *ocsp, int with_logs,
+                                          apr_pool_t *p)
+{
+    md_json_t *json, *certj;
+    md_timeperiod_t certs_valid = {0, 0}, valid;
+    md_cert_t *cert;
+    int i;
+    apr_status_t rv = APR_SUCCESS;   
+    
+    json = md_json_create(p);
+    for (i = 0; i < get_cert_count(md, from_staging); ++i) {
+        cert = APR_ARRAY_IDX(certs, i, md_cert_t*);
+        if (!cert) continue;
+
+        rv = status_get_cert_json_ex(&certj, cert, md, reg, ocsp, with_logs, p);
+        if (APR_SUCCESS != rv) goto leave;
+        valid = md_cert_get_valid(cert);
+        certs_valid = i? md_timeperiod_common(&certs_valid, &valid) : valid;
+        md_json_setj(certj, json, get_cert_name(md, i, from_staging, p), NULL);
+    }
+    
+    if (certs_valid.start) {
+        md_json_set_timeperiod(&certs_valid, json, MD_KEY_VALID, NULL);
+    }
+leave:
+    *pjson = (APR_SUCCESS == rv)? json : NULL;
+    return rv;
+}
+
+static apr_status_t get_staging_certs_json(md_json_t **pjson, const md_t *md, 
+                                           md_reg_t *reg, apr_pool_t *p)
+{ 
+    md_pkey_spec_t *spec;
+    int i;
+    apr_array_header_t *chain, *certs;
+    const md_cert_t *cert;
+    apr_status_t rv;
+    
+    certs = apr_array_make(p, 5, sizeof(md_cert_t*));
+    for (i = 0; i < get_cert_count(md, 1); ++i) {
+        spec = md_pkeys_spec_get(md->pks, i);
+        cert = NULL;
+        rv = md_pubcert_load(md_reg_store_get(reg), MD_SG_STAGING, md->name, spec, &chain, p);
+        if (APR_SUCCESS == rv) {
+            cert = APR_ARRAY_IDX(chain, 0, const md_cert_t*);
+        }
+        APR_ARRAY_PUSH(certs, const md_cert_t*) = cert;
+    }
+    return status_get_certs_json(pjson, certs, 1, md, reg, NULL, 0, p);
+}
+
+static apr_status_t status_get_md_json(md_json_t **pjson, const md_t *md, 
+                                       md_reg_t *reg, md_ocsp_reg_t *ocsp, 
+                                       int with_logs, apr_pool_t *p)
+{
+    md_json_t *mdj, *certsj, *jobj;
+    int renew;
+    const md_pubcert_t *pubcert;
+    const md_cert_t *cert = NULL;
+    apr_array_header_t *certs;
+    apr_status_t rv = APR_SUCCESS;
+    apr_time_t renew_at;
+    int i;
+
+    mdj = md_to_public_json(md, p);
+    certs = apr_array_make(p, 5, sizeof(md_cert_t*));
+    for (i = 0; i < get_cert_count(md, 0); ++i) {
+        cert = NULL;
+        if (APR_SUCCESS == md_reg_get_pubcert(&pubcert, reg, md, i, p)) {
+            cert = APR_ARRAY_IDX(pubcert->certs, 0, const md_cert_t*);
+        }
+        APR_ARRAY_PUSH(certs, const md_cert_t*) = cert;
+    }
+    
+    rv = status_get_certs_json(&certsj, certs, 0, md, reg, ocsp, with_logs, p);
+    if (APR_SUCCESS != rv) goto leave;
+    md_json_setj(certsj, mdj, MD_KEY_CERT, NULL);
+    
+    renew_at = md_reg_renew_at(reg, md, p);
+    if (renew_at > 0) {
+        md_json_set_time(renew_at, mdj, MD_KEY_RENEW_AT, NULL);
+    }
+    
+    md_json_setb(md->stapling, mdj, MD_KEY_STAPLING, NULL);
+    md_json_setb(md->watched, mdj, MD_KEY_WATCHED, NULL);
+    renew = md_reg_should_renew(reg, md, p);
+    if (renew) {
+        md_json_setb(renew, mdj, MD_KEY_RENEW, NULL);
+        rv = job_loadj(&jobj, MD_SG_STAGING, md->name, reg, with_logs, p);
+        if (APR_SUCCESS == rv) {
+            if (APR_SUCCESS == get_staging_certs_json(&certsj, md, reg, p)) {
+                md_json_setj(certsj, jobj, MD_KEY_CERT, NULL);
+            }
+            md_json_setj(jobj, mdj, MD_KEY_RENEWAL, NULL);
+        }
+        else if (APR_STATUS_IS_ENOENT(rv)) rv = APR_SUCCESS;
+        else goto leave;
+    }
+    
+leave:
+    if (APR_SUCCESS != rv) {
+        md_json_setl(rv, mdj, MD_KEY_ERROR, NULL);
+    }
+    *pjson = mdj;
+    return rv;
+}
+
+apr_status_t md_status_get_md_json(md_json_t **pjson, const md_t *md, 
+                                   md_reg_t *reg, md_ocsp_reg_t *ocsp, apr_pool_t *p)
+{
+    return status_get_md_json(pjson, md, reg, ocsp, 1, p);
+}
+
+apr_status_t md_status_get_json(md_json_t **pjson, apr_array_header_t *mds, 
+                                md_reg_t *reg, md_ocsp_reg_t *ocsp, apr_pool_t *p) 
+{
+    md_json_t *json, *mdj;
+    const md_t *md;
+    int i;
+    
+    json = md_json_create(p);
+    md_json_sets(MOD_MD_VERSION, json, MD_KEY_VERSION, NULL);
+    for (i = 0; i < mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(mds, i, const md_t *);
+        status_get_md_json(&mdj, md, reg, ocsp, 0, p);
+        md_json_addj(mdj, json, MD_KEY_MDS, NULL);
+    }
+    *pjson = json;
+    return APR_SUCCESS;
+}
+
+/**************************************************************************************************/
+/* drive job persistence */
+
+md_job_t *md_job_make(apr_pool_t *p, md_store_t *store,
+                      md_store_group_t group, const char *name,
+                      apr_time_t min_delay)
+{
+    md_job_t *job = apr_pcalloc(p, sizeof(*job));
+    job->group = group;
+    job->mdomain = apr_pstrdup(p, name);
+    job->store = store;
+    job->p = p;
+    job->max_log = 128;
+    job->min_delay = min_delay;
+    return job;
+}
+
+void md_job_set_group(md_job_t *job, md_store_group_t group)
+{
+    job->group = group;
+}
+
+static void md_job_from_json(md_job_t *job, md_json_t *json, apr_pool_t *p)
+{
+    const char *s;
+    
+    /* not good, this is malloced from a temp pool */
+    /*job->mdomain = md_json_gets(json, MD_KEY_NAME, NULL);*/
+    job->finished = md_json_getb(json, MD_KEY_FINISHED, NULL);
+    job->notified = md_json_getb(json, MD_KEY_NOTIFIED, NULL);
+    job->notified_renewed = md_json_getb(json, MD_KEY_NOTIFIED_RENEWED, NULL);
+    s = md_json_dups(p, json, MD_KEY_NEXT_RUN, NULL);
+    if (s && *s) job->next_run = apr_date_parse_rfc(s);
+    s = md_json_dups(p, json, MD_KEY_LAST_RUN, NULL);
+    if (s && *s) job->last_run = apr_date_parse_rfc(s);
+    s = md_json_dups(p, json, MD_KEY_VALID_FROM, NULL);
+    if (s && *s) job->valid_from = apr_date_parse_rfc(s);
+    job->error_runs = (int)md_json_getl(json, MD_KEY_ERRORS, NULL);
+    if (md_json_has_key(json, MD_KEY_LAST, NULL)) {
+        job->last_result = md_result_from_json(md_json_getcj(json, MD_KEY_LAST, NULL), p);
+    }
+    job->log = md_json_getj(json, MD_KEY_LOG, NULL);
+}
+
+static void job_to_json(md_json_t *json, const md_job_t *job, 
+                        md_result_t *result, apr_pool_t *p)
+{
+    char ts[APR_RFC822_DATE_LEN];
+
+    md_json_sets(job->mdomain, json, MD_KEY_NAME, NULL);
+    md_json_setb(job->finished, json, MD_KEY_FINISHED, NULL);
+    md_json_setb(job->notified, json, MD_KEY_NOTIFIED, NULL);
+    md_json_setb(job->notified_renewed, json, MD_KEY_NOTIFIED_RENEWED, NULL);
+    if (job->next_run > 0) {
+        apr_rfc822_date(ts, job->next_run);
+        md_json_sets(ts, json, MD_KEY_NEXT_RUN, NULL);
+    }
+    if (job->last_run > 0) {
+        apr_rfc822_date(ts, job->last_run);
+        md_json_sets(ts, json, MD_KEY_LAST_RUN, NULL);
+    }
+    if (job->valid_from > 0) {
+        apr_rfc822_date(ts, job->valid_from);
+        md_json_sets(ts, json, MD_KEY_VALID_FROM, NULL);
+    }
+    md_json_setl(job->error_runs, json, MD_KEY_ERRORS, NULL);
+    if (!result) result = job->last_result;
+    if (result) {
+        md_json_setj(md_result_to_json(result, p), json, MD_KEY_LAST, NULL);
+    }
+    if (job->log) md_json_setj(job->log, json, MD_KEY_LOG, NULL);
+}
+
+apr_status_t md_job_load(md_job_t *job)
+{
+    md_json_t *jprops;
+    apr_status_t rv;
+    
+    rv = md_store_load_json(job->store, job->group, job->mdomain, MD_FN_JOB, &jprops, job->p);
+    if (APR_SUCCESS == rv) {
+        md_job_from_json(job, jprops, job->p);
+    }
+    return rv;
+}
+
+apr_status_t md_job_save(md_job_t *job, md_result_t *result, apr_pool_t *p)
+{
+    md_json_t *jprops;
+    apr_status_t rv;
+    
+    jprops = md_json_create(p);
+    job_to_json(jprops, job, result, p);
+    rv = md_store_save_json(job->store, p, job->group, job->mdomain, MD_FN_JOB, jprops, 0);
+    if (APR_SUCCESS == rv) job->dirty = 0;
+    return rv;
+}
+
+void md_job_log_append(md_job_t *job, const char *type, 
+                       const char *status, const char *detail)
+{
+    md_json_t *entry;
+    char ts[APR_RFC822_DATE_LEN];
+    
+    entry = md_json_create(job->p);
+    apr_rfc822_date(ts, apr_time_now());
+    md_json_sets(ts, entry, MD_KEY_WHEN, NULL);
+    md_json_sets(type, entry, MD_KEY_TYPE, NULL);
+    if (status) md_json_sets(status, entry, MD_KEY_STATUS, NULL);
+    if (detail) md_json_sets(detail, entry, MD_KEY_DETAIL, NULL);
+    if (!job->log) job->log = md_json_create(job->p);
+    md_json_insertj(entry, 0, job->log, MD_KEY_ENTRIES, NULL);
+    md_json_limita(job->max_log, job->log, MD_KEY_ENTRIES, NULL);
+    job->dirty = 1;
+}
+
+typedef struct {
+    md_job_t *job;
+    const char *type;
+    md_json_t *entry;
+    size_t index;
+} log_find_ctx;
+
+static int find_first_log_entry(void *baton, size_t index, md_json_t *entry)
+{
+    log_find_ctx *ctx = baton;
+    const char *etype;
+    
+    etype = md_json_gets(entry, MD_KEY_TYPE, NULL);
+    if (etype == ctx->type || (etype && ctx->type && !strcmp(etype, ctx->type))) {
+        ctx->entry = entry;
+        ctx->index = index;
+        return 0;
+    }
+    return 1;
+}
+
+md_json_t *md_job_log_get_latest(md_job_t *job, const char *type)
+
+{
+    log_find_ctx ctx;
+
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.job = job;
+    ctx.type = type;
+    if (job->log) md_json_itera(find_first_log_entry, &ctx, job->log, MD_KEY_ENTRIES, NULL);
+    return ctx.entry;
+}
+
+apr_time_t md_job_log_get_time_of_latest(md_job_t *job, const char *type)
+{
+    md_json_t *entry;
+    const char *s;
+    
+    entry = md_job_log_get_latest(job, type);
+    if (entry) {
+        s = md_json_gets(entry, MD_KEY_WHEN, NULL);
+        if (s) return apr_date_parse_rfc(s);
+    }
+    return 0;
+}
+
+void  md_status_take_stock(md_json_t **pjson, apr_array_header_t *mds, 
+                           md_reg_t *reg, apr_pool_t *p)
+{
+    const md_t *md;
+    md_job_t *job;
+    int i, complete, renewing, errored, ready, total;
+    md_json_t *json;
+
+    json = md_json_create(p);
+    complete = renewing = errored = ready = total = 0;
+    for (i = 0; i < mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(mds, i, const md_t *);
+        ++total;
+        switch (md->state) {
+            case MD_S_COMPLETE: ++complete; /* fall through */
+            case MD_S_INCOMPLETE:
+                if (md_reg_should_renew(reg, md, p)) {
+                    ++renewing;
+                    job = md_reg_job_make(reg, md->name, p);
+                    if (APR_SUCCESS == md_job_load(job)) {
+                        if (job->error_runs > 0 
+                            || (job->last_result && job->last_result->status != APR_SUCCESS)) {
+                            ++errored;
+                        }
+                        else if (job->finished) {
+                            ++ready;
+                        }
+                    }
+                }
+                break;
+            default: ++errored; break;
+        }
+    }
+    md_json_setl(total, json, MD_KEY_TOTAL, NULL);
+    md_json_setl(complete, json, MD_KEY_COMPLETE, NULL);
+    md_json_setl(renewing, json, MD_KEY_RENEWING, NULL);
+    md_json_setl(errored, json, MD_KEY_ERRORED, NULL);
+    md_json_setl(ready, json, MD_KEY_READY, NULL);
+    *pjson = json;
+}
+
+typedef struct {
+    apr_pool_t *p;
+    md_job_t *job;
+    md_store_t *store;
+    md_result_t *last;
+    apr_time_t last_save;
+} md_job_result_ctx;
+
+static void job_result_update(md_result_t *result, void *data)
+{
+    md_job_result_ctx *ctx = data;
+    apr_time_t now;
+    const char *msg, *sep;
+    
+    if (md_result_cmp(ctx->last, result)) {
+        now = apr_time_now();
+        md_result_assign(ctx->last, result);
+        if (result->activity || result->problem || result->detail) {
+            msg = sep = "";
+            if (result->activity) {
+                msg = apr_psprintf(result->p, "%s", result->activity);
+                sep = ": ";
+            }
+            if (result->detail) {
+                msg = apr_psprintf(result->p, "%s%s%s", msg, sep, result->detail);
+                sep = ", ";
+            }
+            if (result->problem) {
+                msg = apr_psprintf(result->p, "%s%sproblem: %s", msg, sep, result->problem);
+                sep = " ";
+            }
+            md_job_log_append(ctx->job, "progress", NULL, msg);
+
+            if (ctx->store && apr_time_as_msec(now - ctx->last_save) > 500) {
+                md_job_save(ctx->job, result, ctx->p);
+                ctx->last_save = now;
+            }
+        }
+    }
+}
+
+static apr_status_t job_result_raise(md_result_t *result, void *data, const char *event, apr_pool_t *p)
+{
+    md_job_result_ctx *ctx = data;
+    (void)p;
+    if (result == ctx->job->observing) {
+        return md_job_notify(ctx->job, event, result);
+    }
+    return APR_SUCCESS;
+}
+
+static void job_result_holler(md_result_t *result, void *data, const char *event, apr_pool_t *p)
+{
+    md_job_result_ctx *ctx = data;
+    if (result == ctx->job->observing) {
+        md_event_holler(event, ctx->job->mdomain, ctx->job, result, p);
+    }
+}
+
+static void job_observation_start(md_job_t *job, md_result_t *result, md_store_t *store)
+{
+    md_job_result_ctx *ctx;
+
+    if (job->observing) md_result_on_change(job->observing, NULL, NULL);
+    job->observing = result;
+    
+    ctx = apr_pcalloc(result->p, sizeof(*ctx));
+    ctx->p = result->p;
+    ctx->job = job;
+    ctx->store = store;
+    ctx->last = md_result_md_make(result->p, APR_SUCCESS);
+    md_result_assign(ctx->last, result);
+    md_result_on_change(result, job_result_update, ctx);
+    md_result_on_raise(result, job_result_raise, ctx);
+    md_result_on_holler(result, job_result_holler, ctx);
+}
+
+static void job_observation_end(md_job_t *job)
+{
+    if (job->observing) md_result_on_change(job->observing, NULL, NULL);
+    job->observing = NULL; 
+} 
+
+void md_job_start_run(md_job_t *job, md_result_t *result, md_store_t *store)
+{
+    job->fatal_error = 0;
+    job->last_run = apr_time_now();
+    job_observation_start(job, result, store);
+    md_job_log_append(job, "starting", NULL, NULL);
+}
+
+apr_time_t md_job_delay_on_errors(md_job_t *job, int err_count, const char *last_problem)
+{
+    apr_time_t delay = 0, max_delay = apr_time_from_sec(24*60*60); /* daily */
+    unsigned char c;
+
+    if (last_problem && md_acme_problem_is_input_related(last_problem)) {
+        /* If ACME server reported a problem and that problem indicates that our
+         * input values, e.g. our configuration, has something wrong, we always
+         * go to max delay as frequent retries are unlikely to resolve the situation.
+         * However, we should nevertheless retry daily, bc. it might be that there
+         * is a bug in the server. Unlikely, but... */
+        delay = max_delay;
+    }
+    else if (err_count > 0) {
+        /* back off duration, depending on the errors we encounter in a row */
+        delay = job->min_delay << (err_count - 1);
+        if (delay > max_delay) {
+            delay = max_delay;
+        }
+    }
+    if (delay > 0) {
+        /* jitter the delay by +/- 0-50%.
+         * Background: we see retries of jobs being too regular (e.g. all at midnight),
+         * possibly cumulating from many installations that restart their Apache at a
+         * fixed hour. This can contribute to an overload at the CA and a continuation
+         * of failure.
+         */
+        md_rand_bytes(&c, sizeof(c), job->p);
+        delay += apr_time_from_sec((apr_time_sec(delay) * (c - 128)) / 256);
+    }
+    return delay;
+}
+
+void md_job_end_run(md_job_t *job, md_result_t *result)
+{
+    if (APR_SUCCESS == result->status) {
+        job->finished = 1;
+        job->valid_from = result->ready_at;
+        job->error_runs = 0;
+        job->dirty = 1;
+        md_job_log_append(job, "finished", NULL, NULL);
+    }
+    else {
+        ++job->error_runs;
+        job->dirty = 1;
+        job->next_run = apr_time_now() + md_job_delay_on_errors(job, job->error_runs, result->problem);
+    }
+    job_observation_end(job);
+}
+
+void md_job_retry_at(md_job_t *job, apr_time_t later)
+{
+    job->next_run = later;
+    job->dirty = 1;
+}
+
+apr_status_t md_job_notify(md_job_t *job, const char *reason, md_result_t *result)
+{
+    apr_status_t rv;
+    
+    md_result_set(result, APR_SUCCESS, NULL);
+    rv = md_event_raise(reason, job->mdomain, job, result, job->p);
+    job->dirty = 1;
+    if (APR_SUCCESS == rv && APR_SUCCESS == result->status) {
+        job->notified = 1;
+        if (!strcmp("renewed", reason)) {
+            job->notified_renewed = 1;
+        }
+    }
+    else {
+        ++job->error_runs;
+        job->next_run = apr_time_now() + md_job_delay_on_errors(job, job->error_runs, result->problem);
+    }
+    return result->status;
+}
+
diff --git a/modules/md/md_status.h b/modules/md/md_status.h
new file mode 100644
index 0000000..f4d09bd
--- /dev/null
+++ b/modules/md/md_status.h
@@ -0,0 +1,126 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef md_status_h
+#define md_status_h
+
+struct md_json_t;
+struct md_reg_t;
+struct md_result_t;
+struct md_ocsp_reg_t;
+
+#include "md_store.h"
+
+/** 
+ * Get a JSON summary of the MD and its status (certificates, jobs, etc.).
+ */
+apr_status_t md_status_get_md_json(struct md_json_t **pjson, const md_t *md, 
+                                   struct md_reg_t *reg, struct md_ocsp_reg_t *ocsp,
+                                   apr_pool_t *p);
+
+/** 
+ * Get a JSON summary of all MDs and their status.
+ */
+apr_status_t md_status_get_json(struct md_json_t **pjson, apr_array_header_t *mds, 
+                                struct md_reg_t *reg, struct md_ocsp_reg_t *ocsp,
+                                apr_pool_t *p);
+
+/**
+ * Take stock of all MDs given for a short overview. The JSON returned
+ * will carry integers for MD_KEY_COMPLETE, MD_KEY_RENEWING, 
+ * MD_KEY_ERRORED, MD_KEY_READY and MD_KEY_TOTAL.
+ */
+void  md_status_take_stock(struct md_json_t **pjson, apr_array_header_t *mds, 
+                           struct md_reg_t *reg, apr_pool_t *p);
+
+
+typedef struct md_job_t md_job_t;
+
+struct md_job_t {
+    md_store_group_t group;/* group where job is persisted */
+    const char *mdomain;   /* Name of the MD this job is about */
+    md_store_t *store;     /* store where it is persisted */
+    apr_pool_t *p;     
+    apr_time_t next_run;   /* Time this job wants to be processed next */
+    apr_time_t last_run;   /* Time this job ran last (or 0) */
+    struct md_result_t *last_result; /* Result from last run */
+    int finished;          /* true iff the job finished successfully */
+    int notified;          /* true iff notifications were handled successfully */
+    int notified_renewed;  /* true iff a 'renewed' notification was handled successfully */
+    apr_time_t valid_from; /* at which time the finished job results become valid, 0 if immediate */
+    int error_runs;        /* Number of errored runs of an unfinished job */
+    int fatal_error;       /* a fatal error is remedied by retrying */
+    md_json_t *log;        /* array of log objects with minimum fields
+                              MD_KEY_WHEN (timestamp) and MD_KEY_TYPE (string) */
+    apr_size_t max_log;    /* max number of log entries, new ones replace oldest */
+    int dirty;
+    struct md_result_t *observing;
+    apr_time_t min_delay;  /* smallest delay a repeated attempt should have */
+};
+
+/**
+ * Create a new job instance for the given MD name. 
+ * Job load/save will work using the name.
+ */
+md_job_t *md_job_make(apr_pool_t *p, md_store_t *store, 
+                      md_store_group_t group, const char *name,
+                      apr_time_t min_delay);
+
+void md_job_set_group(md_job_t *job, md_store_group_t group);
+
+/**
+ * Update the job from storage in <group>/job->mdomain.
+ */
+apr_status_t md_job_load(md_job_t *job);
+
+/**
+ * Update storage from job in <group>/job->mdomain.
+ */
+apr_status_t md_job_save(md_job_t *job, struct md_result_t *result, apr_pool_t *p);
+
+/**
+ * Append to the job's log. Timestamp is automatically added.
+ * @param type          type of log entry
+ * @param status        status of entry (maybe NULL)
+ * @param detail        description of what happened
+ */
+void md_job_log_append(md_job_t *job, const char *type, 
+                       const char *status, const char *detail);
+
+/**
+ * Retrieve the latest log entry of a certain type.
+ */
+md_json_t *md_job_log_get_latest(md_job_t *job, const char *type);
+
+/**
+ * Get the time the latest log entry of the given type happened, or 0 if
+ * none is found.
+ */
+apr_time_t md_job_log_get_time_of_latest(md_job_t *job, const char *type);
+
+void md_job_start_run(md_job_t *job, struct md_result_t *result, md_store_t *store);
+void md_job_end_run(md_job_t *job, struct md_result_t *result);
+void md_job_retry_at(md_job_t *job, apr_time_t later);
+
+/**
+ * Given the number of errors and the last problem encountered,
+ * recommend a delay for the next attempt of job
+ */
+apr_time_t md_job_delay_on_errors(md_job_t *job, int err_count, const char *last_problem);
+
+apr_status_t md_job_notify(md_job_t *job, const char *reason, struct md_result_t *result);
+
+#endif /* md_status_h */
diff --git a/modules/md/md_store.c b/modules/md/md_store.c
new file mode 100644
index 0000000..59dbd67
--- /dev/null
+++ b/modules/md/md_store.c
@@ -0,0 +1,385 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_file_info.h>
+#include <apr_file_io.h>
+#include <apr_fnmatch.h>
+#include <apr_hash.h>
+#include <apr_strings.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_log.h"
+#include "md_json.h"
+#include "md_store.h"
+#include "md_util.h"
+
+/**************************************************************************************************/
+/* generic callback handling */
+
+#define ASPECT_MD           "md.json"
+#define ASPECT_CERT         "cert.pem"
+#define ASPECT_PKEY         "key.pem"
+#define ASPECT_CHAIN        "chain.pem"
+
+#define GNAME_ACCOUNTS     
+#define GNAME_CHALLENGES   
+#define GNAME_DOMAINS      
+#define GNAME_STAGING      
+#define GNAME_ARCHIVE      
+
+static const char *GROUP_NAME[] = {
+    "none",
+    "accounts",
+    "challenges",
+    "domains",
+    "staging",
+    "archive",
+    "tmp",
+    "ocsp",
+    NULL
+};
+
+const char *md_store_group_name(unsigned int group)
+{
+    if (group < sizeof(GROUP_NAME)/sizeof(GROUP_NAME[0])) {
+        return GROUP_NAME[group];
+    }
+    return "UNKNOWN";
+}
+
+apr_status_t md_store_load(md_store_t *store, md_store_group_t group, 
+                           const char *name, const char *aspect, 
+                           md_store_vtype_t vtype, void **pdata, 
+                           apr_pool_t *p)
+{
+    return store->load(store, group, name, aspect, vtype, pdata, p);
+}
+
+apr_status_t md_store_save(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                           const char *name, const char *aspect, 
+                           md_store_vtype_t vtype, void *data, 
+                           int create)
+{
+    return store->save(store, p, group, name, aspect, vtype, data, create);
+}
+
+apr_status_t md_store_remove(md_store_t *store, md_store_group_t group, 
+                             const char *name, const char *aspect, 
+                             apr_pool_t *p, int force)
+{
+    return store->remove(store, group, name, aspect, p, force);
+}
+
+apr_status_t md_store_purge(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                             const char *name)
+{
+    return store->purge(store, p, group, name);
+}
+
+apr_status_t md_store_iter(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                           apr_pool_t *p, md_store_group_t group, const char *pattern, 
+                           const char *aspect, md_store_vtype_t vtype)
+{
+    return store->iterate(inspect, baton, store, p, group, pattern, aspect, vtype);
+}
+
+apr_status_t md_store_load_json(md_store_t *store, md_store_group_t group, 
+                                const char *name, const char *aspect, 
+                                struct md_json_t **pdata, apr_pool_t *p)
+{
+    return md_store_load(store, group, name, aspect, MD_SV_JSON, (void**)pdata, p);
+}
+
+apr_status_t md_store_save_json(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                                const char *name, const char *aspect, 
+                                struct md_json_t *data, int create)
+{
+    return md_store_save(store, p, group, name, aspect, MD_SV_JSON, (void*)data, create);
+}
+
+apr_status_t md_store_move(md_store_t *store, apr_pool_t *p, 
+                           md_store_group_t from, md_store_group_t to,
+                           const char *name, int archive)
+{
+    return store->move(store, p, from, to, name, archive);
+}
+
+apr_status_t md_store_get_fname(const char **pfname, 
+                                md_store_t *store, md_store_group_t group, 
+                                const char *name, const char *aspect, 
+                                apr_pool_t *p)
+{
+    if (store->get_fname) {
+        return store->get_fname(pfname, store, group, name, aspect, p);
+    }
+    return APR_ENOTIMPL;
+}
+
+int md_store_is_newer(md_store_t *store, md_store_group_t group1, md_store_group_t group2,  
+                      const char *name, const char *aspect, apr_pool_t *p)
+{
+    return store->is_newer(store, group1, group2, name, aspect, p);
+}
+
+apr_time_t md_store_get_modified(md_store_t *store, md_store_group_t group,  
+                                 const char *name, const char *aspect, apr_pool_t *p)
+{
+    return store->get_modified(store, group, name, aspect, p);
+}
+
+apr_status_t md_store_iter_names(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                                 apr_pool_t *p, md_store_group_t group, const char *pattern)
+{
+    return store->iterate_names(inspect, baton, store, p, group, pattern);
+}
+
+apr_status_t md_store_remove_not_modified_since(md_store_t *store, apr_pool_t *p, 
+                                                apr_time_t modified,
+                                                md_store_group_t group, 
+                                                const char *name, 
+                                                const char *aspect)
+{
+    return store->remove_nms(store, p, modified, group, name, aspect);
+}
+
+apr_status_t md_store_rename(md_store_t *store, apr_pool_t *p,
+                             md_store_group_t group, const char *name, const char *to)
+{
+    return store->rename(store, p, group, name, to);
+}
+
+/**************************************************************************************************/
+/* convenience */
+
+typedef struct {
+    md_store_t *store;
+    md_store_group_t group;
+} md_group_ctx;
+
+apr_status_t md_load(md_store_t *store, md_store_group_t group, 
+                     const char *name, md_t **pmd, apr_pool_t *p)
+{
+    md_json_t *json;
+    apr_status_t rv;
+    
+    rv = md_store_load_json(store, group, name, MD_FN_MD, pmd? &json : NULL, p);
+    if (APR_SUCCESS == rv) {
+        if (pmd) {
+            *pmd = md_from_json(json, p);
+        }
+        return APR_SUCCESS;
+    }
+    return rv;
+}
+
+static apr_status_t p_save(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_group_ctx *ctx = baton;
+    md_json_t *json;
+    md_t *md;
+    int create;
+    
+    md = va_arg(ap, md_t *);
+    create = va_arg(ap, int);
+
+    json = md_to_json(md, ptemp);
+    assert(json);
+    assert(md->name);
+    return md_store_save_json(ctx->store, p, ctx->group, md->name, MD_FN_MD, json, create);
+}
+
+apr_status_t md_save(md_store_t *store, apr_pool_t *p, 
+                     md_store_group_t group, md_t *md, int create)
+{
+    md_group_ctx ctx;
+    
+    ctx.store = store;
+    ctx.group = group;
+    return md_util_pool_vdo(p_save, &ctx, p, md, create, NULL);
+}
+
+static apr_status_t p_remove(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_group_ctx *ctx = baton;
+    const char *name;
+    int force;
+    
+    (void)p;
+    name = va_arg(ap, const char *);
+    force = va_arg(ap, int);
+
+    assert(name);
+    return md_store_remove(ctx->store, ctx->group, name, MD_FN_MD, ptemp, force);
+}
+
+apr_status_t md_remove(md_store_t *store, apr_pool_t *p, 
+                       md_store_group_t group, const char *name, int force)
+{
+    md_group_ctx ctx;
+    
+    ctx.store = store;
+    ctx.group = group;
+    return md_util_pool_vdo(p_remove, &ctx, p, name, force, NULL);
+}
+
+int md_is_newer(md_store_t *store, md_store_group_t group1, md_store_group_t group2,  
+                      const char *name, apr_pool_t *p)
+{
+    return md_store_is_newer(store, group1, group2, name, MD_FN_MD, p);
+}
+
+
+typedef struct {
+    apr_pool_t *p;
+    apr_array_header_t *mds;
+} md_load_ctx;
+
+static const char *pk_filename(const char *keyname, const char *base, apr_pool_t *p)
+{
+    char *s, *t;
+    /* We also run on various filesystems with difference upper/lower preserve matching
+     * rules. Normalize the names we use, since private key specifications are basically
+     * user input. */
+    s = (keyname && apr_strnatcasecmp("rsa", keyname))?
+        apr_pstrcat(p, base, ".", keyname, ".pem", NULL)
+        : apr_pstrcat(p, base, ".pem", NULL);
+    for (t = s; *t; t++ )
+        *t = (char)apr_tolower(*t);
+    return s;
+}
+
+const char *md_pkey_filename(md_pkey_spec_t *spec, apr_pool_t *p)
+{
+    return pk_filename(md_pkey_spec_name(spec), "privkey", p);
+}
+
+const char *md_chain_filename(md_pkey_spec_t *spec, apr_pool_t *p)
+{
+    return pk_filename(md_pkey_spec_name(spec), "pubcert", p);
+}
+
+apr_status_t md_pkey_load(md_store_t *store, md_store_group_t group, const char *name, 
+                          md_pkey_spec_t *spec, md_pkey_t **ppkey, apr_pool_t *p)
+{
+    const char *fname = md_pkey_filename(spec, p);
+    return md_store_load(store, group, name, fname, MD_SV_PKEY, (void**)ppkey, p);
+}
+
+apr_status_t md_pkey_save(md_store_t *store, apr_pool_t *p, md_store_group_t group, const char *name, 
+                          md_pkey_spec_t *spec, struct md_pkey_t *pkey, int create)
+{
+    const char *fname = md_pkey_filename(spec, p);
+    return md_store_save(store, p, group, name, fname, MD_SV_PKEY, pkey, create);
+}
+
+apr_status_t md_pubcert_load(md_store_t *store, md_store_group_t group, const char *name, 
+                             md_pkey_spec_t *spec, struct apr_array_header_t **ppubcert, 
+                             apr_pool_t *p)
+{
+    const char *fname = md_chain_filename(spec, p);
+    return md_store_load(store, group, name, fname, MD_SV_CHAIN, (void**)ppubcert, p);
+}
+
+apr_status_t md_pubcert_save(md_store_t *store, apr_pool_t *p, 
+                             md_store_group_t group, const char *name, 
+                             md_pkey_spec_t *spec, struct apr_array_header_t *pubcert, int create)
+{
+    const char *fname = md_chain_filename(spec, p);
+    return md_store_save(store, p, group, name, fname, MD_SV_CHAIN, pubcert, create);
+}
+
+apr_status_t md_creds_load(md_store_t *store, md_store_group_t group, const char *name, 
+                           md_pkey_spec_t *spec, md_credentials_t **pcreds, apr_pool_t *p)
+{
+    md_credentials_t *creds = apr_pcalloc(p, sizeof(*creds));
+    apr_status_t rv;
+    
+    creds->spec = spec;
+    if (APR_SUCCESS != (rv = md_pkey_load(store, group, name, spec, &creds->pkey, p))) {
+        goto leave;
+    }
+    /* chain is optional */
+    rv = md_pubcert_load(store, group, name, spec, &creds->chain, p);
+    if (APR_STATUS_IS_ENOENT(rv)) rv = APR_SUCCESS;
+leave:
+    *pcreds = (APR_SUCCESS == rv)? creds : NULL;
+    return rv;
+}
+
+apr_status_t md_creds_save(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                           const char *name, md_credentials_t *creds, int create)
+{
+    apr_status_t rv;
+
+    if (APR_SUCCESS != (rv = md_pkey_save(store, p, group, name, creds->spec, creds->pkey, create))) {
+        goto leave;
+    }
+    rv = md_pubcert_save(store, p, group, name, creds->spec, creds->chain, create);
+leave:
+    return rv;
+}
+
+typedef struct {
+    md_store_t *store;
+    md_store_group_t group;
+    const char *pattern;
+    const char *aspect;
+    md_store_md_inspect *inspect;
+    void *baton;
+} inspect_md_ctx;
+
+static int insp_md(void *baton, const char *name, const char *aspect, 
+                   md_store_vtype_t vtype, void *value, apr_pool_t *ptemp)
+{
+    inspect_md_ctx *ctx = baton;
+    
+    if (!strcmp(MD_FN_MD, aspect) && vtype == MD_SV_JSON) {
+        md_t *md = md_from_json(value, ptemp);
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, ptemp, "inspecting md at: %s", name);
+        return ctx->inspect(ctx->baton, ctx->store, md, ptemp);
+    }
+    return 1;
+}
+
+apr_status_t md_store_md_iter(md_store_md_inspect *inspect, void *baton, md_store_t *store, 
+                              apr_pool_t *p, md_store_group_t group, const char *pattern)
+{
+    inspect_md_ctx ctx;
+    
+    ctx.store = store;
+    ctx.group = group;
+    ctx.inspect = inspect;
+    ctx.baton = baton;
+    
+    return md_store_iter(insp_md, &ctx, store, p, group, pattern, MD_FN_MD, MD_SV_JSON);
+}
+
+apr_status_t md_store_lock_global(md_store_t *store, apr_pool_t *p, apr_time_t max_wait)
+{
+    return store->lock_global(store, p, max_wait);
+}
+
+void md_store_unlock_global(md_store_t *store, apr_pool_t *p)
+{
+    store->unlock_global(store, p);
+}
diff --git a/modules/md/md_store.h b/modules/md/md_store.h
new file mode 100644
index 0000000..73c840f
--- /dev/null
+++ b/modules/md/md_store.h
@@ -0,0 +1,343 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_store_h
+#define mod_md_md_store_h
+
+struct apr_array_header_t;
+struct md_cert_t;
+struct md_pkey_t;
+struct md_pkey_spec_t;
+
+const char *md_store_group_name(unsigned int group);
+
+typedef struct md_store_t md_store_t;
+
+/**
+ * A store for domain related data.
+ *
+ * The Key for a piece of data is the set of 3 items
+ *   <group> + <domain> + <aspect>
+ *
+ * Examples:
+ * "domains" + "greenbytes.de" + "pubcert.pem"
+ * "ocsp" + "greenbytes.de" + "ocsp-XXXXX.json"
+ *
+ * Storage groups are pre-defined, domain and aspect names can be freely chosen.
+ *
+ * Groups reflect use cases and come with security restrictions. The groups 
+ * DOMAINS, ARCHIVE and NONE are only accessible during the startup 
+ * phase of httpd.
+ *
+ * Private key are stored unencrypted only in restricted groups. Meaning that certificate
+ * keys in group DOMAINS are not encrypted, but only readable at httpd start/reload.
+ * Keys in unrestricted groups are encrypted using a pass phrase generated once and stored
+ * in NONE.
+ */
+
+/** Value types handled by a store */
+typedef enum {
+    MD_SV_TEXT,         /* plain text, value is (char*) */
+    MD_SV_JSON,         /* JSON serialization, value is (md_json_t*) */
+    MD_SV_CERT,         /* PEM x509 certificate, value is (md_cert_t*) */
+    MD_SV_PKEY,         /* PEM private key, value is (md_pkey_t*) */
+    MD_SV_CHAIN,        /* list of PEM x509 certificates, value is 
+                           (apr_array_header_t*) of (md_cert*) */
+} md_store_vtype_t;
+
+/** Store storage groups */
+typedef enum {
+    MD_SG_NONE,         /* top level of store, name MUST be NULL in calls */
+    MD_SG_ACCOUNTS,     /* ACME accounts */
+    MD_SG_CHALLENGES,   /* challenge response data for a domain */ 
+    MD_SG_DOMAINS,      /* live certificates and settings for a domain */
+    MD_SG_STAGING,      /* staged set of certificate and settings, maybe incomplete */
+    MD_SG_ARCHIVE,      /* Archived live sets of a domain */
+    MD_SG_TMP,          /* temporary domain storage */
+    MD_SG_OCSP,         /* OCSP stapling related domain data */
+    MD_SG_COUNT,        /* number of storage groups, used in setups */
+} md_store_group_t;
+
+#define MD_FN_MD                "md.json"
+#define MD_FN_JOB               "job.json"
+#define MD_FN_HTTPD_JSON        "httpd.json"
+
+/* The corresponding names for current cert & key files are constructed
+ * in md_store and md_crypt.
+ */
+
+/* These three legacy filenames are only used in md_store_fs to
+ * upgrade 1.0 directories.  They should not be used for any other
+ * purpose.
+ */
+#define MD_FN_PRIVKEY           "privkey.pem"
+#define MD_FN_PUBCERT           "pubcert.pem"
+#define MD_FN_CERT              "cert.pem"
+
+/**
+ * Load the JSON value at key "group/name/aspect", allocated from pool p.
+ * @return APR_ENOENT if there is no such value
+ */
+apr_status_t md_store_load_json(md_store_t *store, md_store_group_t group, 
+                                const char *name, const char *aspect, 
+                                struct md_json_t **pdata, apr_pool_t *p);
+/**
+ * Save the JSON value at key "group/name/aspect". If create != 0, fail if there
+ * already is a value for this key.
+ */
+apr_status_t md_store_save_json(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                                const char *name, const char *aspect, 
+                                struct md_json_t *data, int create);
+
+/**
+ * Load the value of type at key "group/name/aspect", allocated from pool p. Usually, the
+ * type is expected to be the same as used in saving the value. Some conversions will work,
+ * others will fail the format.
+ * @return APR_ENOENT if there is no such value
+ */
+apr_status_t md_store_load(md_store_t *store, md_store_group_t group, 
+                           const char *name, const char *aspect, 
+                           md_store_vtype_t vtype, void **pdata, 
+                           apr_pool_t *p);
+/**
+ * Save the JSON value at key "group/name/aspect". If create != 0, fail if there
+ * already is a value for this key. The provided data MUST be of the correct type.
+ */
+apr_status_t md_store_save(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                           const char *name, const char *aspect, 
+                           md_store_vtype_t vtype, void *data, 
+                           int create);
+
+/**
+ * Remove the value stored at key "group/name/aspect". Unless force != 0, a missing
+ * value will cause the call to fail with APR_ENOENT.
+ */ 
+apr_status_t md_store_remove(md_store_t *store, md_store_group_t group, 
+                             const char *name, const char *aspect, 
+                             apr_pool_t *p, int force);
+/**
+ * Remove everything matching key "group/name".
+ */ 
+apr_status_t md_store_purge(md_store_t *store, apr_pool_t *p, 
+                            md_store_group_t group, const char *name);
+
+/**
+ * Remove all items matching the name/aspect patterns that have not been
+ * modified since the given timestamp.
+ */
+apr_status_t md_store_remove_not_modified_since(md_store_t *store, apr_pool_t *p, 
+                                                apr_time_t modified,
+                                                md_store_group_t group, 
+                                                const char *name, 
+                                                const char *aspect);
+
+/**
+ * inspect callback function. Invoked for each matched value. Values allocated from
+ * ptemp may disappear any time after the call returned. If this function returns
+ * 0, the iteration is aborted. 
+ */
+typedef int md_store_inspect(void *baton, const char *name, const char *aspect, 
+                             md_store_vtype_t vtype, void *value, apr_pool_t *ptemp);
+
+/**
+ * Iterator over all existing values matching the name pattern. Patterns are evaluated
+ * using apr_fnmatch() without flags.
+ */
+apr_status_t md_store_iter(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                           apr_pool_t *p, md_store_group_t group, const char *pattern, 
+                           const char *aspect, md_store_vtype_t vtype);
+
+/**
+ * Move everything matching key "from/name" from one group to another. If archive != 0,
+ * move any existing "to/name" into a new "archive/new_name" location.
+ */
+apr_status_t md_store_move(md_store_t *store, apr_pool_t *p,
+                           md_store_group_t from, md_store_group_t to,
+                           const char *name, int archive);
+
+/**
+ * Rename a group member.
+ */
+apr_status_t md_store_rename(md_store_t *store, apr_pool_t *p,
+                             md_store_group_t group, const char *name, const char *to);
+
+/**
+ * Get the filename of an item stored in "group/name/aspect". The item does
+ * not have to exist.
+ */
+apr_status_t md_store_get_fname(const char **pfname, 
+                                md_store_t *store, md_store_group_t group, 
+                                const char *name, const char *aspect, 
+                                apr_pool_t *p);
+
+/**
+ * Make a compare on the modification time of "group1/name/aspect" vs. "group2/name/aspect".
+ */
+int md_store_is_newer(md_store_t *store, md_store_group_t group1, md_store_group_t group2,  
+                      const char *name, const char *aspect, apr_pool_t *p);
+
+/**
+ * Iterate over all names that exist in a group, e.g. there are items matching
+ * "group/pattern". The inspect function is called with the name and NULL aspect
+ * and value.
+ */
+apr_status_t md_store_iter_names(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                                 apr_pool_t *p, md_store_group_t group, const char *pattern);
+
+/**
+ * Get the modification time of the item store under "group/name/aspect".
+ * @return modification time or 0 if the item does not exist.
+ */
+apr_time_t md_store_get_modified(md_store_t *store, md_store_group_t group,  
+                                 const char *name, const char *aspect, apr_pool_t *p);
+
+/**
+ * Acquire a cooperative, global lock on store modifications.
+
+ * This will only prevent other children/processes/cluster nodes from
+ * doing the same and does not protect individual store functions from
+ * being called without it.
+ * @param store the store
+ * @param p memory pool to use
+ * @param max_wait maximum time to wait in order to acquire
+ * @return APR_SUCCESS when lock was obtained
+ */
+apr_status_t md_store_lock_global(md_store_t *store, apr_pool_t *p, apr_time_t max_wait);
+
+/**
+ * Realease the global store lock. Will do nothing if there is no lock.
+ */
+void md_store_unlock_global(md_store_t *store, apr_pool_t *p);
+
+/**************************************************************************************************/
+/* Storage handling utils */
+
+apr_status_t md_load(md_store_t *store, md_store_group_t group, 
+                     const char *name, md_t **pmd, apr_pool_t *p);
+apr_status_t md_save(struct md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                     md_t *md, int create);
+apr_status_t md_remove(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                     const char *name, int force);
+
+int md_is_newer(md_store_t *store, md_store_group_t group1, md_store_group_t group2,  
+                const char *name, apr_pool_t *p);
+
+typedef int md_store_md_inspect(void *baton, md_store_t *store, md_t *md, apr_pool_t *ptemp);
+
+apr_status_t md_store_md_iter(md_store_md_inspect *inspect, void *baton, md_store_t *store, 
+                              apr_pool_t *p, md_store_group_t group, const char *pattern);
+
+
+const char *md_pkey_filename(struct md_pkey_spec_t *spec, apr_pool_t *p);
+const char *md_chain_filename(struct md_pkey_spec_t *spec, apr_pool_t *p);
+
+apr_status_t md_pkey_load(md_store_t *store, md_store_group_t group, 
+                          const char *name, struct md_pkey_spec_t *spec,
+                          struct md_pkey_t **ppkey, apr_pool_t *p);
+apr_status_t md_pkey_save(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                          const char *name, struct md_pkey_spec_t *spec,
+                          struct md_pkey_t *pkey, int create);
+
+apr_status_t md_pubcert_load(md_store_t *store, md_store_group_t group, const char *name, 
+                             struct md_pkey_spec_t *spec, struct apr_array_header_t **ppubcert, 
+                             apr_pool_t *p);
+apr_status_t md_pubcert_save(md_store_t *store, apr_pool_t *p, 
+                             md_store_group_t group, const char *name, 
+                             struct md_pkey_spec_t *spec, 
+                             struct apr_array_header_t *pubcert, int create);
+
+/**************************************************************************************************/
+/* X509 complete credentials */
+
+typedef struct md_credentials_t md_credentials_t;
+struct md_credentials_t {
+    struct md_pkey_spec_t *spec;
+    struct md_pkey_t *pkey;
+    struct apr_array_header_t *chain;
+};
+
+apr_status_t md_creds_load(md_store_t *store, md_store_group_t group, const char *name, 
+                           struct md_pkey_spec_t *spec, md_credentials_t **pcreds, apr_pool_t *p);
+apr_status_t md_creds_save(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                           const char *name, md_credentials_t *creds, int create);
+
+/**************************************************************************************************/
+/* implementation interface */
+
+typedef apr_status_t md_store_load_cb(md_store_t *store, md_store_group_t group, 
+                                      const char *name, const char *aspect, 
+                                      md_store_vtype_t vtype, void **pvalue, 
+                                      apr_pool_t *p);
+typedef apr_status_t md_store_save_cb(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                                      const char *name, const char *aspect, 
+                                      md_store_vtype_t vtype, void *value, 
+                                      int create);
+typedef apr_status_t md_store_remove_cb(md_store_t *store, md_store_group_t group, 
+                                        const char *name, const char *aspect,  
+                                        apr_pool_t *p, int force);
+typedef apr_status_t md_store_purge_cb(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                                        const char *name);
+
+typedef apr_status_t md_store_iter_cb(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                                      apr_pool_t *p, md_store_group_t group, const char *pattern,
+                                      const char *aspect, md_store_vtype_t vtype);
+
+typedef apr_status_t md_store_names_iter_cb(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                                            apr_pool_t *p, md_store_group_t group, const char *pattern);
+
+typedef apr_status_t md_store_move_cb(md_store_t *store, apr_pool_t *p, md_store_group_t from, 
+                                      md_store_group_t to, const char *name, int archive);
+
+typedef apr_status_t md_store_rename_cb(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                                        const char *from, const char *to);
+
+typedef apr_status_t md_store_get_fname_cb(const char **pfname, 
+                                           md_store_t *store, md_store_group_t group, 
+                                           const char *name, const char *aspect, 
+                                           apr_pool_t *p);
+
+typedef int md_store_is_newer_cb(md_store_t *store, 
+                                 md_store_group_t group1, md_store_group_t group2,  
+                                 const char *name, const char *aspect, apr_pool_t *p);
+
+typedef apr_time_t md_store_get_modified_cb(md_store_t *store, md_store_group_t group,  
+                                            const char *name, const char *aspect, apr_pool_t *p);
+
+typedef apr_status_t md_store_remove_nms_cb(md_store_t *store, apr_pool_t *p, 
+                                            apr_time_t modified, md_store_group_t group, 
+                                            const char *name, const char *aspect);
+typedef apr_status_t md_store_lock_global_cb(md_store_t *store, apr_pool_t *p, apr_time_t max_wait);
+typedef void md_store_unlock_global_cb(md_store_t *store, apr_pool_t *p);
+
+struct md_store_t {
+    md_store_save_cb *save;
+    md_store_load_cb *load;
+    md_store_remove_cb *remove;
+    md_store_move_cb *move;
+    md_store_rename_cb *rename;
+    md_store_iter_cb *iterate;
+    md_store_names_iter_cb *iterate_names;
+    md_store_purge_cb *purge;
+    md_store_get_fname_cb *get_fname;
+    md_store_is_newer_cb *is_newer;
+    md_store_get_modified_cb *get_modified;
+    md_store_remove_nms_cb *remove_nms;
+    md_store_lock_global_cb *lock_global;
+    md_store_unlock_global_cb *unlock_global;
+};
+
+
+#endif /* mod_md_md_store_h */
diff --git a/modules/md/md_store_fs.c b/modules/md/md_store_fs.c
new file mode 100644
index 0000000..35c24b4
--- /dev/null
+++ b/modules/md/md_store_fs.c
@@ -0,0 +1,1169 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_file_info.h>
+#include <apr_file_io.h>
+#include <apr_fnmatch.h>
+#include <apr_hash.h>
+#include <apr_strings.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_log.h"
+#include "md_store.h"
+#include "md_store_fs.h"
+#include "md_util.h"
+#include "md_version.h"
+
+/**************************************************************************************************/
+/* file system based implementation of md_store_t */
+
+#define MD_STORE_VERSION        3
+#define MD_FS_LOCK_NAME         "store.lock"
+
+typedef struct {
+    apr_fileperms_t dir;
+    apr_fileperms_t file;
+} perms_t;
+
+typedef struct md_store_fs_t md_store_fs_t;
+struct md_store_fs_t {
+    md_store_t s;
+    
+    const char *base;       /* base directory of store */
+    perms_t def_perms;
+    perms_t group_perms[MD_SG_COUNT];
+    md_store_fs_cb *event_cb;
+    void *event_baton;
+    
+    md_data_t key;
+    int plain_pkey[MD_SG_COUNT];
+    
+    int port_80;
+    int port_443;
+
+    apr_file_t *global_lock;
+};
+
+#define FS_STORE(store)     (md_store_fs_t*)(((char*)store)-offsetof(md_store_fs_t, s))
+#define FS_STORE_JSON       "md_store.json"
+#define FS_STORE_KLEN       48
+
+static apr_status_t fs_load(md_store_t *store, md_store_group_t group, 
+                            const char *name, const char *aspect,  
+                            md_store_vtype_t vtype, void **pvalue, apr_pool_t *p);
+static apr_status_t fs_save(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                            const char *name, const char *aspect,  
+                            md_store_vtype_t vtype, void *value, int create);
+static apr_status_t fs_remove(md_store_t *store, md_store_group_t group, 
+                              const char *name, const char *aspect, 
+                              apr_pool_t *p, int force);
+static apr_status_t fs_purge(md_store_t *store, apr_pool_t *p, 
+                             md_store_group_t group, const char *name);
+static apr_status_t fs_remove_nms(md_store_t *store, apr_pool_t *p, 
+                                  apr_time_t modified, md_store_group_t group, 
+                                  const char *name, const char *aspect);
+static apr_status_t fs_move(md_store_t *store, apr_pool_t *p, 
+                            md_store_group_t from, md_store_group_t to, 
+                            const char *name, int archive);
+static apr_status_t fs_rename(md_store_t *store, apr_pool_t *p, 
+                            md_store_group_t group, const char *from, const char *to);
+static apr_status_t fs_iterate(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                               apr_pool_t *p, md_store_group_t group,  const char *pattern,
+                               const char *aspect, md_store_vtype_t vtype);
+static apr_status_t fs_iterate_names(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                                     apr_pool_t *p, md_store_group_t group, const char *pattern);
+
+static apr_status_t fs_get_fname(const char **pfname, 
+                                 md_store_t *store, md_store_group_t group, 
+                                 const char *name, const char *aspect, 
+                                 apr_pool_t *p);
+static int fs_is_newer(md_store_t *store, md_store_group_t group1, md_store_group_t group2,  
+                       const char *name, const char *aspect, apr_pool_t *p);
+
+static apr_time_t fs_get_modified(md_store_t *store, md_store_group_t group,  
+                                  const char *name, const char *aspect, apr_pool_t *p);
+
+static apr_status_t fs_lock_global(md_store_t *store, apr_pool_t *p, apr_time_t max_wait);
+static void fs_unlock_global(md_store_t *store, apr_pool_t *p);
+
+static apr_status_t init_store_file(md_store_fs_t *s_fs, const char *fname, 
+                                    apr_pool_t *p, apr_pool_t *ptemp)
+{
+    md_json_t *json = md_json_create(p);
+    const char *key64;
+    apr_status_t rv;
+    
+    md_json_setn(MD_STORE_VERSION, json, MD_KEY_STORE, MD_KEY_VERSION, NULL);
+
+    md_data_pinit(&s_fs->key, FS_STORE_KLEN, p);
+    if (APR_SUCCESS != (rv = md_rand_bytes((unsigned char*)s_fs->key.data, s_fs->key.len, p))) {
+        return rv;
+    }
+        
+    key64 = md_util_base64url_encode(&s_fs->key, ptemp);
+    md_json_sets(key64, json, MD_KEY_KEY, NULL);
+    rv = md_json_fcreatex(json, ptemp, MD_JSON_FMT_INDENT, fname, MD_FPROT_F_UONLY);
+    memset((char*)key64, 0, strlen(key64));
+
+    return rv;
+}
+
+static apr_status_t rename_pkey(void *baton, apr_pool_t *p, apr_pool_t *ptemp, 
+                                const char *dir, const char *name, 
+                                apr_filetype_e ftype)
+{
+    const char *from, *to;
+    apr_status_t rv = APR_SUCCESS;
+    
+    (void)baton;
+    (void)ftype;
+    if (   MD_OK(md_util_path_merge(&from, ptemp, dir, name, NULL))
+        && MD_OK(md_util_path_merge(&to, ptemp, dir, MD_FN_PRIVKEY, NULL))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, p, "renaming %s/%s to %s", 
+                      dir, name, MD_FN_PRIVKEY);
+        return apr_file_rename(from, to, ptemp);
+    }
+    return rv;
+}
+
+static apr_status_t mk_pubcert(void *baton, apr_pool_t *p, apr_pool_t *ptemp, 
+                               const char *dir, const char *name, 
+                               apr_filetype_e ftype)
+{
+    md_cert_t *cert;
+    apr_array_header_t *chain, *pubcert;
+    const char *fname, *fpubcert;
+    apr_status_t rv = APR_SUCCESS;
+    
+    (void)baton;
+    (void)ftype;
+    (void)p;
+    if (   MD_OK(md_util_path_merge(&fpubcert, ptemp, dir, MD_FN_PUBCERT, NULL))
+        && APR_STATUS_IS_ENOENT(rv = md_chain_fload(&pubcert, ptemp, fpubcert))
+        && MD_OK(md_util_path_merge(&fname, ptemp, dir, name, NULL))
+        && MD_OK(md_cert_fload(&cert, ptemp, fname))
+        && MD_OK(md_util_path_merge(&fname, ptemp, dir, "chain.pem", NULL))) {
+        
+        rv = md_chain_fload(&chain, ptemp, fname);
+        if (APR_STATUS_IS_ENOENT(rv)) {
+            chain = apr_array_make(ptemp, 1, sizeof(md_cert_t*));
+            rv = APR_SUCCESS;
+        }
+        if (APR_SUCCESS == rv) {
+            pubcert = apr_array_make(ptemp, chain->nelts + 1, sizeof(md_cert_t*));
+            APR_ARRAY_PUSH(pubcert, md_cert_t *) = cert;
+            apr_array_cat(pubcert, chain);
+            rv = md_chain_fsave(pubcert, ptemp, fpubcert, MD_FPROT_F_UONLY);
+        }
+    }
+    return rv;
+}
+
+static apr_status_t upgrade_from_1_0(md_store_fs_t *s_fs, apr_pool_t *p, apr_pool_t *ptemp)
+{
+    md_store_group_t g;
+    apr_status_t rv = APR_SUCCESS;
+    
+    (void)ptemp;
+    /* Migrate pkey.pem -> privkey.pem */
+    for (g = MD_SG_NONE; g < MD_SG_COUNT && APR_SUCCESS == rv; ++g) {
+        rv = md_util_files_do(rename_pkey, s_fs, p, s_fs->base, 
+                              md_store_group_name(g), "*", "pkey.pem", NULL);
+    }
+    /* Generate fullcert.pem from cert.pem and chain.pem where missing */
+    rv = md_util_files_do(mk_pubcert, s_fs, p, s_fs->base, 
+                          md_store_group_name(MD_SG_DOMAINS), "*", MD_FN_CERT, NULL);
+    rv = md_util_files_do(mk_pubcert, s_fs, p, s_fs->base, 
+                          md_store_group_name(MD_SG_ARCHIVE), "*", MD_FN_CERT, NULL);
+    
+    return rv;
+}
+
+static apr_status_t read_store_file(md_store_fs_t *s_fs, const char *fname, 
+                                    apr_pool_t *p, apr_pool_t *ptemp)
+{
+    md_json_t *json;
+    const char *key64;
+    apr_status_t rv;
+    double store_version;
+    
+    if (MD_OK(md_json_readf(&json, p, fname))) {
+        store_version = md_json_getn(json, MD_KEY_STORE, MD_KEY_VERSION, NULL);
+        if (store_version <= 0.0) {
+            /* ok, an old one, compatible to 1.0 */
+            store_version = 1.0;
+        }
+        if (store_version > MD_STORE_VERSION) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "version too new: %f", store_version);
+            return APR_EINVAL;
+        }
+
+        key64 = md_json_dups(p, json, MD_KEY_KEY, NULL);
+        if (!key64) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "missing key: %s", MD_KEY_KEY);
+            return APR_EINVAL;
+        }
+        
+        md_util_base64url_decode(&s_fs->key, key64, p);
+        if (s_fs->key.len != FS_STORE_KLEN) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, 0, p, "key length unexpected: %" APR_SIZE_T_FMT, 
+                          s_fs->key.len);
+            return APR_EINVAL;
+        }
+
+        /* Need to migrate format? */
+        if (store_version < MD_STORE_VERSION) {
+            if (store_version <= 1.0) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, "migrating store v1 -> v2");
+                rv = upgrade_from_1_0(s_fs, p, ptemp);
+            }
+            if (store_version <= 2.0) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, "migrating store v2 -> v3");
+                md_json_del(json, MD_KEY_VERSION, NULL);
+            }
+            
+            if (APR_SUCCESS == rv) {
+                md_json_setn(MD_STORE_VERSION, json, MD_KEY_STORE, MD_KEY_VERSION, NULL);
+                rv = md_json_freplace(json, ptemp, MD_JSON_FMT_INDENT, fname, MD_FPROT_F_UONLY);
+            }
+            md_log_perror(MD_LOG_MARK, MD_LOG_INFO, rv, p, "migrated store");
+        } 
+    }
+    return rv;
+}
+
+static apr_status_t setup_store_file(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_fs_t *s_fs = baton;
+    const char *fname;
+    apr_status_t rv;
+
+    (void)ap;
+    s_fs->plain_pkey[MD_SG_DOMAINS] = 1;
+    /* Added: the encryption of tls-alpn-01 certificate keys is not a security issue
+     * for these self-signed, short-lived certificates. Having them unencrypted let's
+     * use pass around the files insteak of an *SSL implementation dependent PKEY_something.
+     */
+    s_fs->plain_pkey[MD_SG_CHALLENGES] = 1;
+    s_fs->plain_pkey[MD_SG_TMP] = 1;
+    
+    if (!MD_OK(md_util_path_merge(&fname, ptemp, s_fs->base, FS_STORE_JSON, NULL))) {
+        return rv;
+    }
+    
+read:
+    if (MD_OK(md_util_is_file(fname, ptemp))) {
+        rv = read_store_file(s_fs, fname, p, ptemp);
+    }
+    else if (APR_STATUS_IS_ENOENT(rv)
+        && APR_STATUS_IS_EEXIST(rv = init_store_file(s_fs, fname, p, ptemp))) {
+        goto read;
+    }
+    return rv;
+}
+
+apr_status_t md_store_fs_init(md_store_t **pstore, apr_pool_t *p, const char *path)
+{
+    md_store_fs_t *s_fs;
+    apr_status_t rv = APR_SUCCESS;
+    
+    s_fs = apr_pcalloc(p, sizeof(*s_fs));
+
+    s_fs->s.load = fs_load;
+    s_fs->s.save = fs_save;
+    s_fs->s.remove = fs_remove;
+    s_fs->s.move = fs_move;
+    s_fs->s.rename = fs_rename;
+    s_fs->s.purge = fs_purge;
+    s_fs->s.iterate = fs_iterate;
+    s_fs->s.iterate_names = fs_iterate_names;
+    s_fs->s.get_fname = fs_get_fname;
+    s_fs->s.is_newer = fs_is_newer;
+    s_fs->s.get_modified = fs_get_modified;
+    s_fs->s.remove_nms = fs_remove_nms;
+    s_fs->s.lock_global = fs_lock_global;
+    s_fs->s.unlock_global = fs_unlock_global;
+
+    /* by default, everything is only readable by the current user */ 
+    s_fs->def_perms.dir = MD_FPROT_D_UONLY;
+    s_fs->def_perms.file = MD_FPROT_F_UONLY;
+
+    /* Account information needs to be accessible to httpd child processes.
+     * private keys are, similar to staging, encrypted. */
+    s_fs->group_perms[MD_SG_ACCOUNTS].dir = MD_FPROT_D_UALL_WREAD;
+    s_fs->group_perms[MD_SG_ACCOUNTS].file = MD_FPROT_F_UALL_WREAD;
+    s_fs->group_perms[MD_SG_STAGING].dir = MD_FPROT_D_UALL_WREAD;
+    s_fs->group_perms[MD_SG_STAGING].file = MD_FPROT_F_UALL_WREAD;
+    /* challenges dir and files are readable by all, no secrets involved */ 
+    s_fs->group_perms[MD_SG_CHALLENGES].dir = MD_FPROT_D_UALL_WREAD;
+    s_fs->group_perms[MD_SG_CHALLENGES].file = MD_FPROT_F_UALL_WREAD;
+    /* OCSP data is readable by all, no secrets involved */ 
+    s_fs->group_perms[MD_SG_OCSP].dir = MD_FPROT_D_UALL_WREAD;
+    s_fs->group_perms[MD_SG_OCSP].file = MD_FPROT_F_UALL_WREAD;
+
+    s_fs->base = apr_pstrdup(p, path);
+
+    rv = md_util_is_dir(s_fs->base, p);
+    if (APR_STATUS_IS_ENOENT(rv)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_INFO, rv, p,
+            "store directory does not exist, creating %s", s_fs->base);
+        rv = apr_dir_make_recursive(s_fs->base, s_fs->def_perms.dir, p);
+        if (APR_SUCCESS != rv) goto cleanup;
+        rv = apr_file_perms_set(s_fs->base, MD_FPROT_D_UALL_WREAD);
+        if (APR_STATUS_IS_ENOTIMPL(rv)) {
+            rv = APR_SUCCESS;
+        }
+        if (APR_SUCCESS != rv) goto cleanup;
+    }
+    else if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, p,
+            "not a plain directory, maybe a symlink? %s", s_fs->base);
+    }
+
+    rv = md_util_pool_vdo(setup_store_file, s_fs, p, NULL);
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "init fs store at %s", s_fs->base);
+    }
+cleanup:
+    *pstore = (rv == APR_SUCCESS)? &(s_fs->s) : NULL;
+    return rv;
+}
+
+apr_status_t md_store_fs_default_perms_set(md_store_t *store, 
+                                           apr_fileperms_t file_perms,
+                                           apr_fileperms_t dir_perms)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    
+    s_fs->def_perms.file = file_perms;
+    s_fs->def_perms.dir = dir_perms;
+    return APR_SUCCESS;
+}
+
+apr_status_t md_store_fs_group_perms_set(md_store_t *store, md_store_group_t group, 
+                                         apr_fileperms_t file_perms,
+                                         apr_fileperms_t dir_perms)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    
+    if (group >= (sizeof(s_fs->group_perms)/sizeof(s_fs->group_perms[0]))) {
+        return APR_ENOTIMPL;
+    }
+    s_fs->group_perms[group].file = file_perms;
+    s_fs->group_perms[group].dir = dir_perms;
+    return APR_SUCCESS;
+}
+
+apr_status_t md_store_fs_set_event_cb(struct md_store_t *store, md_store_fs_cb *cb, void *baton)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    
+    s_fs->event_cb = cb;
+    s_fs->event_baton = baton;
+    return APR_SUCCESS;
+}
+
+static const perms_t *gperms(md_store_fs_t *s_fs, md_store_group_t group)
+{
+    if (group >= (sizeof(s_fs->group_perms)/sizeof(s_fs->group_perms[0]))
+        || !s_fs->group_perms[group].dir) {
+        return &s_fs->def_perms;
+    }
+    return &s_fs->group_perms[group];
+}
+
+static apr_status_t fs_get_fname(const char **pfname, 
+                                 md_store_t *store, md_store_group_t group, 
+                                 const char *name, const char *aspect, 
+                                 apr_pool_t *p)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    if (group == MD_SG_NONE) {
+        return md_util_path_merge(pfname, p, s_fs->base, aspect, NULL);
+    }
+    return md_util_path_merge(pfname, p, 
+                              s_fs->base, md_store_group_name(group), name, aspect, NULL);
+}
+
+static apr_status_t fs_get_dname(const char **pdname, 
+                                 md_store_t *store, md_store_group_t group, 
+                                 const char *name, apr_pool_t *p)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    if (group == MD_SG_NONE) {
+        *pdname = s_fs->base;
+        return APR_SUCCESS;
+    }
+    return md_util_path_merge(pdname, p, s_fs->base, md_store_group_name(group), name, NULL);
+}
+
+static void get_pass(const char **ppass, apr_size_t *plen, 
+                     md_store_fs_t *s_fs, md_store_group_t group)
+{
+    if (s_fs->plain_pkey[group]) {
+        *ppass = NULL;
+        *plen = 0;
+    }
+    else {
+        *ppass = (const char *)s_fs->key.data;
+        *plen = s_fs->key.len;
+    }
+}
+ 
+static apr_status_t fs_fload(void **pvalue, md_store_fs_t *s_fs, const char *fpath, 
+                             md_store_group_t group, md_store_vtype_t vtype, 
+                             apr_pool_t *p, apr_pool_t *ptemp)
+{
+    apr_status_t rv;
+    const char *pass;
+    apr_size_t pass_len;
+    
+    if (pvalue != NULL) {
+        switch (vtype) {
+            case MD_SV_TEXT:
+                rv = md_text_fread8k((const char **)pvalue, p, fpath);
+                break;
+            case MD_SV_JSON:
+                rv = md_json_readf((md_json_t **)pvalue, p, fpath);
+                break;
+            case MD_SV_CERT:
+                rv = md_cert_fload((md_cert_t **)pvalue, p, fpath);
+                break;
+            case MD_SV_PKEY:
+                get_pass(&pass, &pass_len, s_fs, group);
+                rv = md_pkey_fload((md_pkey_t **)pvalue, p, pass, pass_len, fpath);
+                break;
+            case MD_SV_CHAIN:
+                rv = md_chain_fload((apr_array_header_t **)pvalue, p, fpath);
+                break;
+            default:
+                rv = APR_ENOTIMPL;
+                break;
+        }
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, ptemp, 
+                      "loading type %d from %s", vtype, fpath);
+    }
+    else { /* check for existence only */
+        rv = md_util_is_file(fpath, p);
+    }
+    return rv;
+}
+
+static apr_status_t pfs_load(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_fs_t *s_fs = baton;
+    const char *fpath, *name, *aspect;
+    md_store_vtype_t vtype;
+    md_store_group_t group;
+    void **pvalue;
+    apr_status_t rv;
+    
+    group = (md_store_group_t)va_arg(ap, int);
+    name = va_arg(ap, const char *);
+    aspect = va_arg(ap, const char *);
+    vtype = (md_store_vtype_t)va_arg(ap, int);
+    pvalue= va_arg(ap, void **);
+        
+    if (MD_OK(fs_get_fname(&fpath, &s_fs->s, group, name, aspect, ptemp))) {
+        rv = fs_fload(pvalue, s_fs, fpath, group, vtype, p, ptemp);
+    }
+    return rv;
+}
+
+static apr_status_t dispatch(md_store_fs_t *s_fs, md_store_fs_ev_t ev, unsigned int group, 
+                             const char *fname, apr_filetype_e ftype, apr_pool_t *p)
+{
+    (void)ev;
+    if (s_fs->event_cb) {
+        return s_fs->event_cb(s_fs->event_baton, &s_fs->s, MD_S_FS_EV_CREATED, 
+                              group, fname, ftype, p);
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t mk_group_dir(const char **pdir, md_store_fs_t *s_fs, 
+                                 md_store_group_t group, const char *name,
+                                 apr_pool_t *p)
+{
+    const perms_t *perms;
+    apr_status_t rv;
+    
+    perms = gperms(s_fs, group);
+
+    *pdir = NULL;
+    rv = fs_get_dname(pdir, &s_fs->s, group, name, p);
+    if ((APR_SUCCESS != rv) || (MD_SG_NONE == group)) goto cleanup;
+
+    rv = md_util_is_dir(*pdir, p);
+    if (APR_STATUS_IS_ENOENT(rv)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, p, "not a directory, creating %s", *pdir);
+        rv = apr_dir_make_recursive(*pdir, perms->dir, p);
+        if (APR_SUCCESS != rv) goto cleanup;
+        dispatch(s_fs, MD_S_FS_EV_CREATED, group, *pdir, APR_DIR, p);
+    }
+
+    rv = apr_file_perms_set(*pdir, perms->dir);
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, p, "mk_group_dir %s perm set", *pdir);
+    if (APR_STATUS_IS_ENOTIMPL(rv)) {
+        rv = APR_SUCCESS;
+    }
+cleanup:
+    if (APR_SUCCESS != rv) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "mk_group_dir %d %s",
+            group, (*pdir? *pdir : (name? name : "(null)")));
+    }
+    return rv;
+}
+
+static apr_status_t pfs_is_newer(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_fs_t *s_fs = baton;
+    const char *fname1, *fname2, *name, *aspect;
+    md_store_group_t group1, group2;
+    apr_finfo_t inf1, inf2;
+    int *pnewer;
+    apr_status_t rv;
+    
+    (void)p;
+    group1 = (md_store_group_t)va_arg(ap, int);
+    group2 = (md_store_group_t)va_arg(ap, int);
+    name = va_arg(ap, const char*);
+    aspect = va_arg(ap, const char*);
+    pnewer = va_arg(ap, int*);
+    
+    *pnewer = 0;
+    if (   MD_OK(fs_get_fname(&fname1, &s_fs->s, group1, name, aspect, ptemp))
+        && MD_OK(fs_get_fname(&fname2, &s_fs->s, group2, name, aspect, ptemp))
+        && MD_OK(apr_stat(&inf1, fname1, APR_FINFO_MTIME, ptemp))
+        && MD_OK(apr_stat(&inf2, fname2, APR_FINFO_MTIME, ptemp))) {
+        *pnewer = inf1.mtime > inf2.mtime;
+    }
+
+    return rv;
+}
+
+static int fs_is_newer(md_store_t *store, md_store_group_t group1, md_store_group_t group2,  
+                       const char *name, const char *aspect, apr_pool_t *p)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    int newer = 0;
+    apr_status_t rv;
+    
+    rv = md_util_pool_vdo(pfs_is_newer, s_fs, p, group1, group2, name, aspect, &newer, NULL);
+    if (APR_SUCCESS == rv) {
+        return newer;
+    }
+    return 0;
+}
+
+static apr_status_t pfs_get_modified(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_fs_t *s_fs = baton;
+    const char *fname, *name, *aspect;
+    md_store_group_t group;
+    apr_finfo_t inf;
+    apr_time_t *pmtime;
+    apr_status_t rv;
+    
+    (void)p;
+    group = (md_store_group_t)va_arg(ap, int);
+    name = va_arg(ap, const char*);
+    aspect = va_arg(ap, const char*);
+    pmtime = va_arg(ap, apr_time_t*);
+    
+    *pmtime = 0;
+    if (   MD_OK(fs_get_fname(&fname, &s_fs->s, group, name, aspect, ptemp))
+        && MD_OK(apr_stat(&inf, fname, APR_FINFO_MTIME, ptemp))) {
+        *pmtime = inf.mtime;
+    }
+
+    return rv;
+}
+
+static apr_time_t fs_get_modified(md_store_t *store, md_store_group_t group,  
+                                  const char *name, const char *aspect, apr_pool_t *p)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    apr_time_t mtime;
+    apr_status_t rv;
+    
+    rv = md_util_pool_vdo(pfs_get_modified, s_fs, p, group, name, aspect, &mtime, NULL);
+    if (APR_SUCCESS == rv) {
+        return mtime;
+    }
+    return 0;
+}
+ 
+static apr_status_t pfs_save(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_fs_t *s_fs = baton;
+    const char *gdir, *dir, *fpath, *name, *aspect;
+    md_store_vtype_t vtype;
+    md_store_group_t group;
+    void *value;
+    int create;
+    apr_status_t rv;
+    const perms_t *perms;
+    const char *pass;
+    apr_size_t pass_len;
+    
+    group = (md_store_group_t)va_arg(ap, int);
+    name = va_arg(ap, const char*);
+    aspect = va_arg(ap, const char*);
+    vtype = (md_store_vtype_t)va_arg(ap, int);
+    value = va_arg(ap, void *);
+    create = va_arg(ap, int);
+    
+    perms = gperms(s_fs, group);
+    
+    if (   MD_OK(mk_group_dir(&gdir, s_fs, group, NULL, p)) 
+        && MD_OK(mk_group_dir(&dir, s_fs, group, name, p))
+        && MD_OK(md_util_path_merge(&fpath, ptemp, dir, aspect, NULL))) {
+        
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, 0, ptemp, "storing in %s", fpath);
+        switch (vtype) {
+            case MD_SV_TEXT:
+                rv = (create? md_text_fcreatex(fpath, perms->file, p, value)
+                      : md_text_freplace(fpath, perms->file, p, value));
+                break;
+            case MD_SV_JSON:
+                rv = (create? md_json_fcreatex((md_json_t *)value, p, MD_JSON_FMT_INDENT, 
+                                               fpath, perms->file)
+                      : md_json_freplace((md_json_t *)value, p, MD_JSON_FMT_INDENT, 
+                                         fpath, perms->file));
+                break;
+            case MD_SV_CERT:
+                rv = md_cert_fsave((md_cert_t *)value, ptemp, fpath, perms->file);
+                break;
+            case MD_SV_PKEY:
+                /* Take care that we write private key with access only to the user,
+                 * unless we write the key encrypted */
+                get_pass(&pass, &pass_len, s_fs, group);
+                rv = md_pkey_fsave((md_pkey_t *)value, ptemp, pass, pass_len, 
+                                   fpath, (pass && pass_len)? perms->file : MD_FPROT_F_UONLY);
+                break;
+            case MD_SV_CHAIN:
+                rv = md_chain_fsave((apr_array_header_t*)value, ptemp, fpath, perms->file);
+                break;
+            default:
+                return APR_ENOTIMPL;
+        }
+        if (APR_SUCCESS == rv) {
+            rv = dispatch(s_fs, MD_S_FS_EV_CREATED, group, fpath, APR_REG, p);
+        }
+    }
+    return rv;
+}
+
+static apr_status_t pfs_remove(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_fs_t *s_fs = baton;
+    const char *dir, *name, *fpath, *groupname, *aspect;
+    apr_status_t rv;
+    int force;
+    apr_finfo_t info;
+    md_store_group_t group;
+    
+    (void)p;
+    group = (md_store_group_t)va_arg(ap, int);
+    name = va_arg(ap, const char*);
+    aspect = va_arg(ap, const char *);
+    force = va_arg(ap, int);
+    
+    groupname = md_store_group_name(group);
+    
+    if (   MD_OK(md_util_path_merge(&dir, ptemp, s_fs->base, groupname, name, NULL))
+        && MD_OK(md_util_path_merge(&fpath, ptemp, dir, aspect, NULL))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, ptemp, "start remove of md %s/%s/%s", 
+                      groupname, name, aspect);
+
+        if (!MD_OK(apr_stat(&info, dir, APR_FINFO_TYPE, ptemp))) {
+            if (APR_ENOENT == rv && force) {
+                return APR_SUCCESS;
+            }
+            return rv;
+        }
+    
+        rv = apr_file_remove(fpath, ptemp);
+        if (APR_ENOENT == rv && force) {
+            rv = APR_SUCCESS;
+        }
+    }
+    return rv;
+}
+
+static apr_status_t fs_load(md_store_t *store, md_store_group_t group, 
+                            const char *name, const char *aspect,  
+                            md_store_vtype_t vtype, void **pvalue, apr_pool_t *p)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    return md_util_pool_vdo(pfs_load, s_fs, p, group, name, aspect, vtype, pvalue, NULL);
+}
+
+static apr_status_t fs_save(md_store_t *store, apr_pool_t *p, md_store_group_t group, 
+                            const char *name, const char *aspect,  
+                            md_store_vtype_t vtype, void *value, int create)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    return md_util_pool_vdo(pfs_save, s_fs, p, group, name, aspect, 
+                            vtype, value, create, NULL);
+}
+
+static apr_status_t fs_remove(md_store_t *store, md_store_group_t group, 
+                              const char *name, const char *aspect, 
+                              apr_pool_t *p, int force)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    return md_util_pool_vdo(pfs_remove, s_fs, p, group, name, aspect, force, NULL);
+}
+
+static apr_status_t pfs_purge(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_fs_t *s_fs = baton;
+    const char *dir, *name, *groupname;
+    md_store_group_t group;
+    apr_status_t rv;
+    
+    (void)p;
+    group = (md_store_group_t)va_arg(ap, int);
+    name = va_arg(ap, const char*);
+    
+    groupname = md_store_group_name(group);
+
+    if (MD_OK(md_util_path_merge(&dir, ptemp, s_fs->base, groupname, name, NULL))) {
+        /* Remove all files in dir, there should be no sub-dirs */
+        rv = md_util_rm_recursive(dir, ptemp, 1);
+    }
+    if (!APR_STATUS_IS_ENOENT(rv)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE2, rv, ptemp, "purge %s/%s (%s)", groupname, name, dir);
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t fs_purge(md_store_t *store, apr_pool_t *p, 
+                             md_store_group_t group, const char *name)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    return md_util_pool_vdo(pfs_purge, s_fs, p, group, name, NULL);
+}
+
+/**************************************************************************************************/
+/* iteration */
+
+typedef struct {
+    md_store_fs_t *s_fs;
+    md_store_group_t group;
+    const char *pattern;
+    const char *aspect;
+    md_store_vtype_t vtype;
+    md_store_inspect *inspect;
+    const char *dirname;
+    void *baton;
+    apr_time_t ts;
+} inspect_ctx;
+
+static apr_status_t insp(void *baton, apr_pool_t *p, apr_pool_t *ptemp, 
+                         const char *dir, const char *name, apr_filetype_e ftype)
+{
+    inspect_ctx *ctx = baton;
+    apr_status_t rv;
+    void *value;
+    const char *fpath;
+ 
+    (void)ftype;   
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, ptemp, "inspecting value at: %s/%s", dir, name);
+    if (APR_SUCCESS == (rv = md_util_path_merge(&fpath, ptemp, dir, name, NULL))) {
+        rv = fs_fload(&value, ctx->s_fs, fpath, ctx->group, ctx->vtype, p, ptemp);
+        if (APR_SUCCESS == rv 
+            && !ctx->inspect(ctx->baton, ctx->dirname, name, ctx->vtype, value, p)) {
+            return APR_EOF;
+        }
+        else if (APR_STATUS_IS_ENOENT(rv)) {
+            rv = APR_SUCCESS;
+        }
+    } 
+    return rv;
+}
+
+static apr_status_t insp_dir(void *baton, apr_pool_t *p, apr_pool_t *ptemp, 
+                             const char *dir, const char *name, apr_filetype_e ftype)
+{
+    inspect_ctx *ctx = baton;
+    apr_status_t rv;
+    const char *fpath;
+ 
+    (void)ftype;
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, ptemp, "inspecting dir at: %s/%s", dir, name);
+    if (MD_OK(md_util_path_merge(&fpath, p, dir, name, NULL))) {
+        ctx->dirname = name;
+        rv = md_util_files_do(insp, ctx, p, fpath, ctx->aspect, NULL);
+        if (APR_STATUS_IS_ENOENT(rv)) {
+            rv = APR_SUCCESS;
+        }
+    } 
+    return rv;
+}
+
+static apr_status_t fs_iterate(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                               apr_pool_t *p, md_store_group_t group, const char *pattern, 
+                               const char *aspect, md_store_vtype_t vtype)
+{
+    const char *groupname;
+    apr_status_t rv;
+    inspect_ctx ctx;
+    
+    ctx.s_fs = FS_STORE(store);
+    ctx.group = group;
+    ctx.pattern = pattern;
+    ctx.aspect = aspect;
+    ctx.vtype = vtype;
+    ctx.inspect = inspect;
+    ctx.baton = baton;
+    groupname = md_store_group_name(group);
+
+    rv = md_util_files_do(insp_dir, &ctx, p, ctx.s_fs->base, groupname, pattern, NULL);
+    
+    return rv;
+}
+
+static apr_status_t insp_name(void *baton, apr_pool_t *p, apr_pool_t *ptemp, 
+                              const char *dir, const char *name, apr_filetype_e ftype)
+{
+    inspect_ctx *ctx = baton;
+    
+    (void)ftype;
+    (void)p;
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, ptemp, "inspecting name at: %s/%s", dir, name);
+    return ctx->inspect(ctx->baton, dir, name, 0, NULL, ptemp);
+}
+
+static apr_status_t fs_iterate_names(md_store_inspect *inspect, void *baton, md_store_t *store, 
+                                     apr_pool_t *p, md_store_group_t group, const char *pattern)
+{
+    const char *groupname;
+    apr_status_t rv;
+    inspect_ctx ctx;
+    
+    ctx.s_fs = FS_STORE(store);
+    ctx.group = group;
+    ctx.pattern = pattern;
+    ctx.inspect = inspect;
+    ctx.baton = baton;
+    groupname = md_store_group_name(group);
+
+    rv = md_util_files_do(insp_name, &ctx, p, ctx.s_fs->base, groupname, pattern, NULL);
+    
+    return rv;
+}
+
+static apr_status_t remove_nms_file(void *baton, apr_pool_t *p, apr_pool_t *ptemp, 
+                                    const char *dir, const char *name, apr_filetype_e ftype)
+{
+    inspect_ctx *ctx = baton;
+    const char *fname;
+    apr_finfo_t inf;
+    apr_status_t rv = APR_SUCCESS;
+
+    (void)p;
+    if (APR_DIR == ftype) goto leave;
+    if (APR_SUCCESS != (rv = md_util_path_merge(&fname, ptemp, dir, name, NULL))) goto leave;
+    if (APR_SUCCESS != (rv = apr_stat(&inf, fname, APR_FINFO_MTIME, ptemp))) goto leave;
+    if (inf.mtime >= ctx->ts) goto leave;
+
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, ptemp, "remove_nms file: %s/%s", dir, name);
+    rv = apr_file_remove(fname, ptemp);
+
+leave:
+    return rv;
+}
+
+static apr_status_t remove_nms_dir(void *baton, apr_pool_t *p, apr_pool_t *ptemp, 
+                                   const char *dir, const char *name, apr_filetype_e ftype)
+{
+    inspect_ctx *ctx = baton;
+    apr_status_t rv;
+    const char *fpath;
+ 
+    (void)ftype;
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, ptemp, "remove_nms dir at: %s/%s", dir, name);
+    if (MD_OK(md_util_path_merge(&fpath, p, dir, name, NULL))) {
+        ctx->dirname = name;
+        rv = md_util_files_do(remove_nms_file, ctx, p, fpath, ctx->aspect, NULL);
+        if (APR_STATUS_IS_ENOENT(rv)) {
+            rv = APR_SUCCESS;
+        }
+    } 
+    return rv;
+}
+
+static apr_status_t fs_remove_nms(md_store_t *store, apr_pool_t *p, 
+                                  apr_time_t modified, md_store_group_t group, 
+                                  const char *name, const char *aspect)
+{
+    const char *groupname;
+    apr_status_t rv;
+    inspect_ctx ctx;
+    
+    ctx.s_fs = FS_STORE(store);
+    ctx.group = group;
+    ctx.pattern = name;
+    ctx.aspect = aspect;
+    ctx.ts = modified;
+    groupname = md_store_group_name(group);
+
+    rv = md_util_files_do(remove_nms_dir, &ctx, p, ctx.s_fs->base, groupname, name, NULL);
+    
+    return rv;
+}
+
+/**************************************************************************************************/
+/* moving */
+
+static apr_status_t pfs_move(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_fs_t *s_fs = baton;
+    const char *name, *from_group, *to_group, *from_dir, *to_dir, *arch_dir, *dir;
+    md_store_group_t from, to;
+    int archive;
+    apr_status_t rv;
+    
+    (void)p;
+    from = (md_store_group_t)va_arg(ap, int);
+    to = (md_store_group_t)va_arg(ap, int);
+    name = va_arg(ap, const char*);
+    archive = va_arg(ap, int);
+    
+    from_group = md_store_group_name(from);
+    to_group = md_store_group_name(to);
+    if (!strcmp(from_group, to_group)) {
+        return APR_EINVAL;
+    }
+
+    if (   !MD_OK(md_util_path_merge(&from_dir, ptemp, s_fs->base, from_group, name, NULL))
+        || !MD_OK(md_util_path_merge(&to_dir, ptemp, s_fs->base, to_group, name, NULL))) {
+        goto out;
+    }
+    
+    if (!MD_OK(md_util_is_dir(from_dir, ptemp))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, ptemp, "source is no dir: %s", from_dir);
+        goto out;
+    }
+    
+    if (MD_OK(archive? md_util_is_dir(to_dir, ptemp) : APR_ENOENT)) {
+        int n = 1;
+        const char *narch_dir;
+
+        if (    !MD_OK(md_util_path_merge(&dir, ptemp, s_fs->base, 
+                                          md_store_group_name(MD_SG_ARCHIVE), NULL))
+            || !MD_OK(apr_dir_make_recursive(dir, MD_FPROT_D_UONLY, ptemp))
+            || !MD_OK(md_util_path_merge(&arch_dir, ptemp, dir, name, NULL))) {
+            goto out;
+        }
+        
+#ifdef WIN32
+        /* WIN32 and handling of files/dirs. What can one say? */
+        
+        while (n < 1000) {
+            narch_dir = apr_psprintf(ptemp, "%s.%d", arch_dir, n);
+            rv = md_util_is_dir(narch_dir, ptemp);
+            if (APR_STATUS_IS_ENOENT(rv)) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, ptemp, "using archive dir: %s", 
+                              narch_dir);
+                break;
+            }
+            else {
+                ++n;
+                narch_dir = NULL;
+            }
+        }
+
+#else   /* ifdef WIN32 */
+
+        while (n < 1000) {
+            narch_dir = apr_psprintf(ptemp, "%s.%d", arch_dir, n);
+            if (MD_OK(apr_dir_make(narch_dir, MD_FPROT_D_UONLY, ptemp))) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, ptemp, "using archive dir: %s", 
+                              narch_dir);
+                break;
+            }
+            else if (APR_EEXIST == rv) {
+                ++n;
+                narch_dir = NULL;
+            }
+            else {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, ptemp, "creating archive dir: %s", 
+                              narch_dir);
+                goto out;
+            }
+        }
+         
+#endif   /* ifdef WIN32 (else part) */
+        
+        if (!narch_dir) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, ptemp, "ran out of numbers less than 1000 "
+                          "while looking for an available one in %s to archive the data "
+                          "from %s. Either something is generally wrong or you need to "
+                          "clean up some of those directories.", arch_dir, from_dir);
+            rv = APR_EGENERAL;
+            goto out;
+        }
+        
+        if (!MD_OK(apr_file_rename(to_dir, narch_dir, ptemp))) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, ptemp, "rename from %s to %s",
+                              to_dir, narch_dir);
+                goto out;
+        }
+        if (!MD_OK(apr_file_rename(from_dir, to_dir, ptemp))) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, ptemp, "rename from %s to %s",
+                          from_dir, to_dir);
+            apr_file_rename(narch_dir, to_dir, ptemp);
+            goto out;
+        }
+        if (MD_OK(dispatch(s_fs, MD_S_FS_EV_MOVED, to, to_dir, APR_DIR, ptemp))) {
+            rv = dispatch(s_fs, MD_S_FS_EV_MOVED, MD_SG_ARCHIVE, narch_dir, APR_DIR, ptemp);
+        }
+    }
+    else if (APR_STATUS_IS_ENOENT(rv)) {
+        if (APR_SUCCESS != (rv = apr_file_rename(from_dir, to_dir, ptemp))) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, ptemp, "rename from %s to %s",
+                          from_dir, to_dir);
+            goto out;
+        }
+    }
+    else {
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, rv, ptemp, "target is no dir: %s", to_dir);
+        goto out;
+    }
+    
+out:
+    return rv;
+}
+
+static apr_status_t fs_move(md_store_t *store, apr_pool_t *p, 
+                            md_store_group_t from, md_store_group_t to, 
+                            const char *name, int archive)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    return md_util_pool_vdo(pfs_move, s_fs, p, from, to, name, archive, NULL);
+}
+
+static apr_status_t pfs_rename(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_store_fs_t *s_fs = baton;
+    const char *group_name, *from_dir, *to_dir;
+    md_store_group_t group;
+    const char *from, *to;
+    apr_status_t rv;
+    
+    (void)p;
+    group = (md_store_group_t)va_arg(ap, int);
+    from = va_arg(ap, const char*);
+    to = va_arg(ap, const char*);
+    
+    group_name = md_store_group_name(group);
+    if (   !MD_OK(md_util_path_merge(&from_dir, ptemp, s_fs->base, group_name, from, NULL))
+        || !MD_OK(md_util_path_merge(&to_dir, ptemp, s_fs->base, group_name, to, NULL))) {
+        goto out;
+    }
+    
+    if (APR_SUCCESS != (rv = apr_file_rename(from_dir, to_dir, ptemp))
+        && !APR_STATUS_IS_ENOENT(rv)) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, ptemp, "rename from %s to %s",
+                      from_dir, to_dir);
+        goto out;
+    }
+out:
+    return rv;
+}
+
+static apr_status_t fs_rename(md_store_t *store, apr_pool_t *p, 
+                            md_store_group_t group, const char *from, const char *to)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    return md_util_pool_vdo(pfs_rename, s_fs, p, group, from, to, NULL);
+}
+
+static apr_status_t fs_lock_global(md_store_t *store, apr_pool_t *p, apr_time_t max_wait)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+    apr_status_t rv;
+    const char *lpath;
+    apr_time_t end;
+
+    if (s_fs->global_lock) {
+        rv = APR_EEXIST;
+        md_log_perror(MD_LOG_MARK, MD_LOG_ERR, rv, p, "already locked globally");
+        goto cleanup;
+    }
+
+    rv = md_util_path_merge(&lpath, p, s_fs->base, MD_FS_LOCK_NAME, NULL);
+    if (APR_SUCCESS != rv) goto cleanup;
+    end = apr_time_now() + max_wait;
+
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, 0, p,
+                  "acquire global lock: %s", lpath);
+    while (apr_time_now() < end) {
+        rv = apr_file_open(&s_fs->global_lock, lpath,
+                           (APR_FOPEN_WRITE|APR_FOPEN_CREATE),
+                           MD_FPROT_F_UALL_GREAD, p);
+        if (APR_SUCCESS != rv) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, p,
+                          "unable to create/open lock file: %s",
+                          lpath);
+            goto next_try;
+        }
+        rv = apr_file_lock(s_fs->global_lock,
+                           APR_FLOCK_EXCLUSIVE|APR_FLOCK_NONBLOCK);
+        if (APR_SUCCESS == rv) {
+            goto cleanup;
+        }
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, p,
+                      "unable to obtain lock on: %s",
+                      lpath);
+
+    next_try:
+        if (s_fs->global_lock) {
+            apr_file_close(s_fs->global_lock);
+            s_fs->global_lock = NULL;
+        }
+        apr_sleep(apr_time_from_msec(100));
+    }
+    rv = APR_EGENERAL;
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, p,
+                  "acquire global lock: %s", lpath);
+
+cleanup:
+    return rv;
+}
+
+static void fs_unlock_global(md_store_t *store, apr_pool_t *p)
+{
+    md_store_fs_t *s_fs = FS_STORE(store);
+
+    (void)p;
+    if (s_fs->global_lock) {
+        apr_file_close(s_fs->global_lock);
+        s_fs->global_lock = NULL;
+    }
+}
diff --git a/modules/md/md_store_fs.h b/modules/md/md_store_fs.h
new file mode 100644
index 0000000..dcdb897
--- /dev/null
+++ b/modules/md/md_store_fs.h
@@ -0,0 +1,65 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_store_fs_h
+#define mod_md_md_store_fs_h
+
+struct md_store_t;
+
+/** 
+ * Default file permissions set by the store, user only read/write(/exec),
+ * if so supported by the apr. 
+ */
+#define MD_FPROT_F_UONLY      (APR_FPROT_UREAD|APR_FPROT_UWRITE)
+#define MD_FPROT_D_UONLY      (MD_FPROT_F_UONLY|APR_FPROT_UEXECUTE)
+
+/**
+ * User has all permission, group can read, other none
+ */
+#define MD_FPROT_F_UALL_GREAD (MD_FPROT_F_UONLY|APR_FPROT_GREAD)
+#define MD_FPROT_D_UALL_GREAD (MD_FPROT_D_UONLY|APR_FPROT_GREAD|APR_FPROT_GEXECUTE)
+
+/**
+ * User has all permission, group and others can read
+ */
+#define MD_FPROT_F_UALL_WREAD (MD_FPROT_F_UALL_GREAD|APR_FPROT_WREAD)
+#define MD_FPROT_D_UALL_WREAD (MD_FPROT_D_UALL_GREAD|APR_FPROT_WREAD|APR_FPROT_WEXECUTE)
+
+apr_status_t md_store_fs_init(struct md_store_t **pstore, apr_pool_t *p, 
+                              const char *path);
+
+
+apr_status_t md_store_fs_default_perms_set(struct md_store_t *store, 
+                                           apr_fileperms_t file_perms,
+                                           apr_fileperms_t dir_perms);
+apr_status_t md_store_fs_group_perms_set(struct md_store_t *store, 
+                                         md_store_group_t group, 
+                                         apr_fileperms_t file_perms,
+                                         apr_fileperms_t dir_perms);
+
+typedef enum {
+    MD_S_FS_EV_CREATED,
+    MD_S_FS_EV_MOVED,
+} md_store_fs_ev_t; 
+
+typedef apr_status_t md_store_fs_cb(void *baton, struct md_store_t *store,
+                                    md_store_fs_ev_t ev, unsigned int group, 
+                                    const char *fname, apr_filetype_e ftype,  
+                                    apr_pool_t *p);
+                                    
+apr_status_t md_store_fs_set_event_cb(struct md_store_t *store, md_store_fs_cb *cb, void *baton);
+
+#endif /* mod_md_md_store_fs_h */
diff --git a/modules/md/md_tailscale.c b/modules/md/md_tailscale.c
new file mode 100644
index 0000000..c8d2bad
--- /dev/null
+++ b/modules/md/md_tailscale.c
@@ -0,0 +1,383 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_hash.h>
+#include <apr_uri.h>
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_json.h"
+#include "md_http.h"
+#include "md_log.h"
+#include "md_result.h"
+#include "md_reg.h"
+#include "md_store.h"
+#include "md_util.h"
+
+#include "md_tailscale.h"
+
+typedef struct {
+    apr_pool_t *pool;
+    md_proto_driver_t *driver;
+    const char *unix_socket_path;
+    md_t *md;
+    apr_array_header_t *chain;
+    md_pkey_t *pkey;
+} ts_ctx_t;
+
+static apr_status_t ts_init(md_proto_driver_t *d, md_result_t *result)
+{
+    ts_ctx_t *ts_ctx;
+    apr_uri_t uri;
+    const char *ca_url;
+    apr_status_t rv = APR_SUCCESS;
+
+    md_result_set(result, APR_SUCCESS, NULL);
+    ts_ctx = apr_pcalloc(d->p, sizeof(*ts_ctx));
+    ts_ctx->pool = d->p;
+    ts_ctx->driver = d;
+    ts_ctx->chain = apr_array_make(d->p, 5, sizeof(md_cert_t *));
+
+    ca_url = (d->md->ca_urls && !apr_is_empty_array(d->md->ca_urls))?
+                APR_ARRAY_IDX(d->md->ca_urls, 0, const char*) : NULL;
+    if (!ca_url) {
+        ca_url = MD_TAILSCALE_DEF_URL;
+    }
+    rv = apr_uri_parse(d->p, ca_url, &uri);
+    if (APR_SUCCESS != rv) {
+        md_result_printf(result, rv, "error parsing CA URL `%s`", ca_url);
+        goto leave;
+    }
+    if (uri.scheme && uri.scheme[0] && strcmp("file", uri.scheme)) {
+        rv = APR_ENOTIMPL;
+        md_result_printf(result, rv, "non `file` URLs not supported, CA URL is `%s`",
+                         ca_url);
+        goto leave;
+    }
+    if (uri.hostname && uri.hostname[0] && strcmp("localhost", uri.hostname)) {
+        rv = APR_ENOTIMPL;
+        md_result_printf(result, rv, "non `localhost` URLs not supported, CA URL is `%s`",
+                         ca_url);
+        goto leave;
+    }
+    ts_ctx->unix_socket_path = uri.path;
+    d->baton = ts_ctx;
+
+leave:
+    return rv;
+}
+
+static apr_status_t ts_preload_init(md_proto_driver_t *d, md_result_t *result)
+{
+    return ts_init(d, result);
+}
+
+static apr_status_t ts_preload(md_proto_driver_t *d,
+                               md_store_group_t load_group, md_result_t *result)
+{
+    apr_status_t rv;
+    md_t *md;
+    md_credentials_t *creds;
+    md_pkey_spec_t *pkspec;
+    apr_array_header_t *all_creds;
+    const char *name;
+    int i;
+
+    name = d->md->name;
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: preload start", name);
+    /* Load data from MD_SG_STAGING and save it into "load_group".
+     */
+    if (APR_SUCCESS != (rv = md_load(d->store, MD_SG_STAGING, name, &md, d->p))) {
+        md_result_set(result, rv, "loading staged md.json");
+        goto leave;
+    }
+
+     /* tailscale generates one cert+key with key specification being whatever
+      * it chooses. Use the NULL spec here.
+      */
+    all_creds = apr_array_make(d->p, 5, sizeof(md_credentials_t*));
+    pkspec = NULL;
+    if (APR_SUCCESS != (rv = md_creds_load(d->store, MD_SG_STAGING, name, pkspec, &creds, d->p))) {
+        md_result_printf(result, rv, "loading staged credentials");
+        goto leave;
+    }
+    if (!creds->chain) {
+        rv = APR_ENOENT;
+        md_result_printf(result, rv, "no certificate in staged credentials");
+        goto leave;
+    }
+    if (APR_SUCCESS != (rv = md_check_cert_and_pkey(creds->chain, creds->pkey))) {
+        md_result_printf(result, rv, "certificate and private key do not match in staged credentials");
+        goto leave;
+    }
+    APR_ARRAY_PUSH(all_creds, md_credentials_t*) = creds;
+
+    md_result_activity_setn(result, "purging store tmp space");
+    rv = md_store_purge(d->store, d->p, load_group, name);
+    if (APR_SUCCESS != rv) {
+        md_result_set(result, rv, NULL);
+        goto leave;
+    }
+
+    md_result_activity_setn(result, "saving staged md/privkey/pubcert");
+    if (APR_SUCCESS != (rv = md_save(d->store, d->p, load_group, md, 1))) {
+        md_result_set(result, rv, "writing md.json");
+        goto leave;
+    }
+
+    for (i = 0; i < all_creds->nelts; ++i) {
+        creds = APR_ARRAY_IDX(all_creds, i, md_credentials_t*);
+        if (APR_SUCCESS != (rv = md_creds_save(d->store, d->p, load_group, name, creds, 1))) {
+            md_result_printf(result, rv, "writing credentials #%d", i);
+            goto leave;
+        }
+    }
+
+    md_result_set(result, APR_SUCCESS, "saved staged data successfully");
+
+leave:
+    md_result_log(result, MD_LOG_DEBUG);
+    return rv;
+}
+
+static apr_status_t rv_of_response(const md_http_response_t *res)
+{
+    switch (res->status) {
+        case 200:
+            return APR_SUCCESS;
+        case 400:
+            return APR_EINVAL;
+        case 401: /* sectigo returns this instead of 403 */
+        case 403:
+            return APR_EACCES;
+        case 404:
+            return APR_ENOENT;
+        default:
+            return APR_EGENERAL;
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t on_get_cert(const md_http_response_t *res, void *baton)
+{
+    ts_ctx_t *ts_ctx = baton;
+    apr_status_t rv;
+
+    rv = rv_of_response(res);
+    if (APR_SUCCESS != rv) goto leave;
+    apr_array_clear(ts_ctx->chain);
+    rv = md_cert_chain_read_http(ts_ctx->chain, ts_ctx->pool, res);
+    if (APR_SUCCESS != rv) goto leave;
+
+leave:
+    return rv;
+}
+
+static apr_status_t on_get_key(const md_http_response_t *res, void *baton)
+{
+    ts_ctx_t *ts_ctx = baton;
+    apr_status_t rv;
+
+    rv = rv_of_response(res);
+    if (APR_SUCCESS != rv) goto leave;
+    rv = md_pkey_read_http(&ts_ctx->pkey, ts_ctx->pool, res);
+    if (APR_SUCCESS != rv) goto leave;
+
+leave:
+    return rv;
+}
+
+static apr_status_t ts_renew(md_proto_driver_t *d, md_result_t *result)
+{
+    const char *name, *domain, *url;
+    apr_status_t rv = APR_ENOENT;
+    ts_ctx_t *ts_ctx = d->baton;
+    md_http_t *http;
+    const md_pubcert_t *pubcert;
+    md_cert_t *old_cert, *new_cert;
+    int reset_staging = d->reset;
+
+    /* "renewing" the certificate from tailscale. Since tailscale has its
+     * own ideas on when to do this, we can only inspect the certificate
+     * it gives us and see if it is different from the current one we have.
+     * (if we have any. first time, lacking a cert, any it gives us is
+     *  considered as 'renewed'.)
+     */
+    name = d->md->name;
+    md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: renewing cert", name);
+
+    /* When not explicitly told to reset, we check the existing data. If
+     * it is incomplete or old, we trigger the reset for a clean start. */
+    if (!reset_staging) {
+        md_result_activity_setn(result, "Checking staging area");
+        rv = md_load(d->store, MD_SG_STAGING, d->md->name, &ts_ctx->md, d->p);
+        if (APR_SUCCESS == rv) {
+            /* So, we have a copy in staging, but is it a recent or an old one? */
+            if (md_is_newer(d->store, MD_SG_DOMAINS, MD_SG_STAGING, d->md->name, d->p)) {
+                reset_staging = 1;
+            }
+        }
+        else if (APR_STATUS_IS_ENOENT(rv)) {
+            reset_staging = 1;
+            rv = APR_SUCCESS;
+        }
+    }
+
+    if (reset_staging) {
+        md_result_activity_setn(result, "Resetting staging area");
+        /* reset the staging area for this domain */
+        rv = md_store_purge(d->store, d->p, MD_SG_STAGING, d->md->name);
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE1, rv, d->p,
+                      "%s: reset staging area", d->md->name);
+        if (APR_SUCCESS != rv && !APR_STATUS_IS_ENOENT(rv)) {
+            md_result_printf(result, rv, "resetting staging area");
+            goto leave;
+        }
+        rv = APR_SUCCESS;
+        ts_ctx->md = NULL;
+    }
+
+    if (!ts_ctx->md || !md_array_str_eq(ts_ctx->md->ca_urls, d->md->ca_urls, 1)) {
+        md_result_activity_printf(result, "Resetting staging for %s", d->md->name);
+        /* re-initialize staging */
+        md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, d->p, "%s: setup staging", d->md->name);
+        md_store_purge(d->store, d->p, MD_SG_STAGING, d->md->name);
+        ts_ctx->md = md_copy(d->p, d->md);
+        rv = md_save(d->store, d->p, MD_SG_STAGING, ts_ctx->md, 0);
+        if (APR_SUCCESS != rv) {
+            md_result_printf(result, rv, "Saving MD information in staging area.");
+            md_result_log(result, MD_LOG_ERR);
+            goto leave;
+        }
+    }
+
+    if (!ts_ctx->unix_socket_path) {
+        rv = APR_ENOTIMPL;
+        md_result_set(result, rv, "only unix sockets are supported for tailscale connections");
+        goto leave;
+    }
+
+    rv = md_util_is_unix_socket(ts_ctx->unix_socket_path, d->p);
+    if (APR_SUCCESS != rv) {
+        md_result_printf(result, rv, "tailscale socket not available, may not be up: %s",
+                         ts_ctx->unix_socket_path);
+        goto leave;
+    }
+
+    rv = md_http_create(&http, d->p,
+                        apr_psprintf(d->p, "Apache mod_md/%s", MOD_MD_VERSION),
+                        NULL);
+    if (APR_SUCCESS != rv) {
+        md_result_set(result, rv, "creating http context");
+        goto leave;
+    }
+    md_http_set_unix_socket_path(http, ts_ctx->unix_socket_path);
+
+    domain = (d->md->domains->nelts > 0)?
+              APR_ARRAY_IDX(d->md->domains, 0, const char*) : NULL;
+    if (!domain) {
+        rv = APR_EINVAL;
+        md_result_set(result, rv, "no domain names available");
+    }
+
+    url = apr_psprintf(d->p, "http://localhost/localapi/v0/cert/%s?type=crt",
+                       domain);
+    rv = md_http_GET_perform(http, url, NULL, on_get_cert, ts_ctx);
+    if (APR_SUCCESS != rv) {
+        md_result_set(result, rv, "retrieving certificate from tailscale");
+        goto leave;
+    }
+    if (ts_ctx->chain->nelts <= 0) {
+        rv = APR_ENOENT;
+        md_result_set(result, rv, "tailscale returned no certificates");
+        goto leave;
+    }
+
+    /* Got the key and the chain, is it new? */
+    rv = md_reg_get_pubcert(&pubcert, d->reg,d->md, 0, d->p);
+    if (APR_SUCCESS == rv) {
+        old_cert = APR_ARRAY_IDX(pubcert->certs, 0, md_cert_t*);
+        new_cert = APR_ARRAY_IDX(ts_ctx->chain, 0, md_cert_t*);
+        if (md_certs_are_equal(old_cert, new_cert)) {
+            /* tailscale has not renewed the certificate, yet */
+            rv = APR_ENOENT;
+            md_result_set(result, rv, "tailscale has not renewed the certificate yet");
+            /* let's check this daily */
+            md_result_delay_set(result, apr_time_now() + apr_time_from_sec(MD_SECS_PER_DAY));
+            goto leave;
+        }
+    }
+
+    /* We have a new certificate (or had none before).
+     * Get the key and store both in STAGING.
+     */
+    url = apr_psprintf(d->p, "http://localhost/localapi/v0/cert/%s?type=key",
+                       domain);
+    rv = md_http_GET_perform(http, url, NULL, on_get_key, ts_ctx);
+    if (APR_SUCCESS != rv) {
+        md_result_set(result, rv, "retrieving key from tailscale");
+        goto leave;
+    }
+
+    rv = md_pkey_save(d->store, d->p, MD_SG_STAGING, name, NULL, ts_ctx->pkey, 1);
+    if (APR_SUCCESS != rv) {
+        md_result_set(result, rv, "saving private key");
+        goto leave;
+    }
+
+    rv = md_pubcert_save(d->store, d->p, MD_SG_STAGING, name,
+                         NULL, ts_ctx->chain, 1);
+    if (APR_SUCCESS != rv) {
+        md_result_printf(result, rv, "saving new certificate chain.");
+        goto leave;
+    }
+
+    md_result_set(result, APR_SUCCESS,
+        "A new tailscale certificate has been retrieved successfully and can "
+        "be used. A graceful server restart is recommended.");
+
+leave:
+    md_result_log(result, MD_LOG_DEBUG);
+    return rv;
+}
+
+static apr_status_t ts_complete_md(md_t *md, apr_pool_t *p)
+{
+    (void)p;
+    if (!md->ca_urls) {
+        md->ca_urls = apr_array_make(p, 3, sizeof(const char *));
+        APR_ARRAY_PUSH(md->ca_urls, const char*) = MD_TAILSCALE_DEF_URL;
+    }
+    return APR_SUCCESS;
+}
+
+
+static md_proto_t TAILSCALE_PROTO = {
+    MD_PROTO_TAILSCALE, ts_init, ts_renew,
+    ts_preload_init, ts_preload, ts_complete_md,
+};
+
+apr_status_t md_tailscale_protos_add(apr_hash_t *protos, apr_pool_t *p)
+{
+    (void)p;
+    apr_hash_set(protos, MD_PROTO_TAILSCALE, sizeof(MD_PROTO_TAILSCALE)-1, &TAILSCALE_PROTO);
+    return APR_SUCCESS;
+}
diff --git a/modules/md/md_tailscale.h b/modules/md/md_tailscale.h
new file mode 100644
index 0000000..67a874d
--- /dev/null
+++ b/modules/md/md_tailscale.h
@@ -0,0 +1,25 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_tailscale_h
+#define mod_md_md_tailscale_h
+
+#define MD_PROTO_TAILSCALE      "tailscale"
+
+apr_status_t md_tailscale_protos_add(struct apr_hash_t *protos, apr_pool_t *p);
+
+#endif /* mod_md_md_tailscale_h */
+
diff --git a/modules/md/md_time.c b/modules/md/md_time.c
new file mode 100644
index 0000000..268ca83
--- /dev/null
+++ b/modules/md/md_time.c
@@ -0,0 +1,325 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <stdio.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_time.h>
+
+#include "md.h"
+#include "md_time.h"
+
+apr_time_t md_timeperiod_length(const md_timeperiod_t *period)
+{
+    return (period->start < period->end)? (period->end - period->start) : 0;
+}
+
+int md_timeperiod_contains(const md_timeperiod_t *period, apr_time_t time)
+{
+    return md_timeperiod_has_started(period, time) 
+        && !md_timeperiod_has_ended(period, time);
+}
+
+int md_timeperiod_has_started(const md_timeperiod_t *period, apr_time_t time)
+{
+    return (time >= period->start);
+}
+
+int md_timeperiod_has_ended(const md_timeperiod_t *period, apr_time_t time)
+{
+    return (time >= period->start) && (time <= period->end);
+}
+
+apr_interval_time_t md_timeperiod_remaining(const md_timeperiod_t *period, apr_time_t time)
+{
+    if (time < period->start) return md_timeperiod_length(period);
+    if (time < period->end) return period->end - time;
+    return 0;
+}
+
+char *md_timeperiod_print(apr_pool_t *p, const md_timeperiod_t *period)
+{
+    char tstart[APR_RFC822_DATE_LEN];
+    char tend[APR_RFC822_DATE_LEN];
+
+    apr_rfc822_date(tstart, period->start);
+    apr_rfc822_date(tend, period->end);
+    return apr_pstrcat(p, tstart, " - ", tend, NULL);
+}
+
+static const char *duration_print(apr_pool_t *p, int roughly, apr_interval_time_t duration)
+{
+    const char *s = "", *sep = "";
+    long days = (long)(apr_time_sec(duration) / MD_SECS_PER_DAY);
+    int rem = (int)(apr_time_sec(duration) % MD_SECS_PER_DAY);
+    
+    s = roughly? "~" : "";
+    if (days > 0) {
+        s = apr_psprintf(p, "%s%ld days", s, days);
+        if (roughly) return s;
+        sep = " ";
+    }
+    if (rem > 0) {
+        int hours = (rem / MD_SECS_PER_HOUR);
+        rem = (rem % MD_SECS_PER_HOUR);
+        if (hours > 0) {
+            s = apr_psprintf(p, "%s%s%d hours", s, sep, hours); 
+        if (roughly) return s;
+            sep = " "; 
+        }
+        if (rem > 0) {
+            int minutes = (rem / 60);
+            rem = (rem % 60);
+            if (minutes > 0) {
+                s = apr_psprintf(p, "%s%s%d minutes", s, sep, minutes); 
+                if (roughly) return s;
+                sep = " "; 
+            }
+            if (rem > 0) {
+                s = apr_psprintf(p, "%s%s%d seconds", s, sep, rem); 
+                if (roughly) return s;
+                sep = " "; 
+            }
+        }
+    }
+    else if (days == 0) {
+        s = "0 seconds";
+        if (duration != 0) {
+            s = apr_psprintf(p, "%d ms", (int)apr_time_msec(duration));
+        }
+    }
+    return s;
+}
+
+const char *md_duration_print(apr_pool_t *p, apr_interval_time_t duration)
+{
+    return duration_print(p, 0, duration);
+}
+
+const char *md_duration_roughly(apr_pool_t *p, apr_interval_time_t duration)
+{
+    return duration_print(p, 1, duration);
+}
+
+static const char *duration_format(apr_pool_t *p, apr_interval_time_t duration)
+{
+    const char *s = "0";
+    int units = (int)(apr_time_sec(duration) / MD_SECS_PER_DAY);
+    int rem = (int)(apr_time_sec(duration) % MD_SECS_PER_DAY);
+    
+    if (rem == 0) {
+        s = apr_psprintf(p, "%dd", units); 
+    }
+    else {
+        units = (int)(apr_time_sec(duration) / MD_SECS_PER_HOUR);
+        rem = (int)(apr_time_sec(duration) % MD_SECS_PER_HOUR);
+        if (rem == 0) {
+            s = apr_psprintf(p, "%dh", units); 
+        }
+        else {
+            units = (int)(apr_time_sec(duration) / 60);
+            rem = (int)(apr_time_sec(duration) % 60);
+            if (rem == 0) {
+                s = apr_psprintf(p, "%dmi", units); 
+            }
+            else {
+                units = (int)(apr_time_sec(duration));
+                rem = (int)(apr_time_msec(duration) % 1000);
+                if (rem == 0) {
+                    s = apr_psprintf(p, "%ds", units); 
+                }
+                else {
+                    s = apr_psprintf(p, "%dms", (int)(apr_time_msec(duration))); 
+                }
+            }
+        }
+    }
+    return s;
+}
+
+const char *md_duration_format(apr_pool_t *p, apr_interval_time_t duration)
+{
+    return duration_format(p, duration);
+}
+
+apr_status_t md_duration_parse(apr_interval_time_t *ptimeout, const char *value, 
+                               const char *def_unit)
+{
+    char *endp;
+    apr_int64_t n;
+    
+    n = apr_strtoi64(value, &endp, 10);
+    if (errno) {
+        return errno;
+    }
+    if (!endp || !*endp) {
+        if (!def_unit) def_unit = "s";
+    }
+    else if (endp == value) {
+        return APR_EINVAL;
+    }
+    else {
+        def_unit = endp;
+    }
+    
+    switch (*def_unit) {
+    case 'D':
+    case 'd':
+        *ptimeout = apr_time_from_sec(n * MD_SECS_PER_DAY);
+        break;
+    case 's':
+    case 'S':
+        *ptimeout = (apr_interval_time_t) apr_time_from_sec(n);
+        break;
+    case 'h':
+    case 'H':
+        /* Time is in hours */
+        *ptimeout = (apr_interval_time_t) apr_time_from_sec(n * MD_SECS_PER_HOUR);
+        break;
+    case 'm':
+    case 'M':
+        switch (*(++def_unit)) {
+        /* Time is in milliseconds */
+        case 's':
+        case 'S':
+            *ptimeout = (apr_interval_time_t) n * 1000;
+            break;
+        /* Time is in minutes */
+        case 'i':
+        case 'I':
+            *ptimeout = (apr_interval_time_t) apr_time_from_sec(n * 60);
+            break;
+        default:
+            return APR_EGENERAL;
+        }
+        break;
+    default:
+        return APR_EGENERAL;
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t percentage_parse(const char *value, int *ppercent)
+{
+    char *endp;
+    apr_int64_t n;
+    
+    n = apr_strtoi64(value, &endp, 10);
+    if (errno) {
+        return errno;
+    }
+    if (*endp == '%') {
+        if (n < 0) {
+            return APR_BADARG;
+        }
+        *ppercent = (int)n;
+        return APR_SUCCESS;
+    }
+    return APR_EINVAL;
+}
+
+apr_status_t md_timeslice_create(md_timeslice_t **pts, apr_pool_t *p,
+                                 apr_interval_time_t norm, apr_interval_time_t len)
+{
+    md_timeslice_t *ts;
+
+    ts = apr_pcalloc(p, sizeof(*ts));
+    ts->norm = norm;
+    ts->len = len;
+    *pts = ts;
+    return APR_SUCCESS;
+}
+
+const char *md_timeslice_parse(md_timeslice_t **pts, apr_pool_t *p, 
+                               const char *val, apr_interval_time_t norm)
+{
+    md_timeslice_t *ts;
+    int percent = 0;
+
+    *pts = NULL;
+    if (!val) {
+        return "cannot parse NULL value";
+    }
+
+    ts = apr_pcalloc(p, sizeof(*ts));
+    if (md_duration_parse(&ts->len, val, "d") == APR_SUCCESS) {
+        *pts = ts;
+        return NULL;
+    }
+    else {
+        switch (percentage_parse(val, &percent)) {
+            case APR_SUCCESS:
+                ts->norm = norm;
+                ts->len = apr_time_from_sec((apr_time_sec(norm) * percent / 100L));
+                *pts = ts;
+                return NULL;
+            case APR_BADARG:
+                return "percent must be less than 100";
+        }
+    }
+    return "has unrecognized format";
+}
+
+const char *md_timeslice_format(const md_timeslice_t *ts, apr_pool_t *p) {
+    if (ts->norm > 0) {
+        int percent = (int)(((long)apr_time_sec(ts->len)) * 100L 
+                            / ((long)apr_time_sec(ts->norm))); 
+        return apr_psprintf(p, "%d%%", percent);
+    }
+    return duration_format(p, ts->len);
+}
+
+md_timeperiod_t md_timeperiod_slice_before_end(const md_timeperiod_t *period, 
+                                               const md_timeslice_t *ts)
+{
+    md_timeperiod_t r;
+    apr_time_t duration = ts->len;
+    
+    if (ts->norm > 0) {
+        int percent = (int)(((long)apr_time_sec(ts->len)) * 100L 
+                            / ((long)apr_time_sec(ts->norm))); 
+        apr_time_t plen = md_timeperiod_length(period);
+        if (apr_time_sec(plen) > 100) {
+            duration = apr_time_from_sec(apr_time_sec(plen) * percent / 100);
+        }
+        else {
+            duration = plen * percent / 100;
+        }
+    }
+    r.start = period->end - duration;
+    r.end = period->end;
+    return r;
+}
+
+int md_timeslice_eq(const md_timeslice_t *ts1, const md_timeslice_t *ts2)
+{
+    if (ts1 == ts2) return 1;
+    if (!ts1 || !ts2) return 0;
+    return (ts1->norm == ts2->norm) && (ts1->len == ts2->len);
+}
+
+md_timeperiod_t md_timeperiod_common(const md_timeperiod_t *a, const md_timeperiod_t *b)
+{
+    md_timeperiod_t c;
+    
+    c.start = (a->start > b->start)? a->start : b->start;
+    c.end = (a->end < b->end)? a->end : b->end;
+    if (c.start > c.end) {
+        c.start = c.end = 0;
+    }
+    return c;
+}
diff --git a/modules/md/md_time.h b/modules/md/md_time.h
new file mode 100644
index 0000000..92bd9d8
--- /dev/null
+++ b/modules/md/md_time.h
@@ -0,0 +1,77 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_time_h
+#define mod_md_md_time_h
+
+#include <stdio.h>
+
+#define MD_SECS_PER_HOUR      (60*60)
+#define MD_SECS_PER_DAY       (24*MD_SECS_PER_HOUR)
+
+typedef struct md_timeperiod_t md_timeperiod_t;
+
+struct md_timeperiod_t {
+    apr_time_t start;
+    apr_time_t end;
+};
+
+apr_time_t md_timeperiod_length(const md_timeperiod_t *period);
+
+int md_timeperiod_contains(const md_timeperiod_t *period, apr_time_t time);
+int md_timeperiod_has_started(const md_timeperiod_t *period, apr_time_t time);
+int md_timeperiod_has_ended(const md_timeperiod_t *period, apr_time_t time);
+apr_interval_time_t md_timeperiod_remaining(const md_timeperiod_t *period, apr_time_t time);
+
+/**
+ * Return the timeperiod common between a and b. If both do not overlap, return {0,0}.
+ */
+md_timeperiod_t md_timeperiod_common(const md_timeperiod_t *a, const md_timeperiod_t *b);
+
+char *md_timeperiod_print(apr_pool_t *p, const md_timeperiod_t *period);
+
+/**
+ * Print a human readable form of the give duration in days/hours/min/sec 
+ */
+const char *md_duration_print(apr_pool_t *p, apr_interval_time_t duration);
+const char *md_duration_roughly(apr_pool_t *p, apr_interval_time_t duration);
+
+/**
+ * Parse a machine readable string duration in the form of NN[unit], where
+ * unit is d/h/mi/s/ms with the default given should the unit not be specified.
+ */
+apr_status_t md_duration_parse(apr_interval_time_t *ptimeout, const char *value, 
+                               const char *def_unit);
+const char *md_duration_format(apr_pool_t *p, apr_interval_time_t duration);
+
+typedef struct {
+    apr_interval_time_t norm; /* if > 0, normalized base length */
+    apr_interval_time_t len;  /* length of the timespan */
+} md_timeslice_t;
+
+apr_status_t md_timeslice_create(md_timeslice_t **pts, apr_pool_t *p,
+                                 apr_interval_time_t norm, apr_interval_time_t len); 
+
+int md_timeslice_eq(const md_timeslice_t *ts1, const md_timeslice_t *ts2);
+
+const char *md_timeslice_parse(md_timeslice_t **pts, apr_pool_t *p, 
+                              const char *val, apr_interval_time_t defnorm);
+const char *md_timeslice_format(const md_timeslice_t *ts, apr_pool_t *p);
+
+md_timeperiod_t md_timeperiod_slice_before_end(const md_timeperiod_t *period, 
+                                               const md_timeslice_t *ts);
+
+#endif /* md_util_h */
diff --git a/modules/md/md_util.c b/modules/md/md_util.c
new file mode 100644
index 0000000..884c0bb
--- /dev/null
+++ b/modules/md/md_util.c
@@ -0,0 +1,1561 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <stdio.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_portable.h>
+#include <apr_file_info.h>
+#include <apr_fnmatch.h>
+#include <apr_tables.h>
+#include <apr_uri.h>
+
+#if APR_HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+
+#include "md.h"
+#include "md_log.h"
+#include "md_util.h"
+
+/**************************************************************************************************/
+/* pool utils */
+
+apr_status_t md_util_pool_do(md_util_action *cb, void *baton, apr_pool_t *p)
+{
+    apr_pool_t *ptemp;
+    apr_status_t rv = apr_pool_create(&ptemp, p);
+    if (APR_SUCCESS == rv) {
+        apr_pool_tag(ptemp, "md_pool_do");
+        rv = cb(baton, p, ptemp);
+        apr_pool_destroy(ptemp);
+    }
+    return rv;
+}
+ 
+static apr_status_t pool_vado(md_util_vaction *cb, void *baton, apr_pool_t *p, va_list ap)
+{
+    apr_pool_t *ptemp;
+    apr_status_t rv;
+    
+    rv = apr_pool_create(&ptemp, p);
+    if (APR_SUCCESS == rv) {
+        apr_pool_tag(ptemp, "md_pool_vado");
+        rv = cb(baton, p, ptemp, ap);
+        apr_pool_destroy(ptemp);
+    }
+    return rv;
+}
+ 
+apr_status_t md_util_pool_vdo(md_util_vaction *cb, void *baton, apr_pool_t *p, ...)
+{
+    va_list ap;
+    apr_status_t rv;
+    
+    va_start(ap, p);
+    rv = pool_vado(cb, baton, p, ap);
+    va_end(ap);
+    return rv;
+}
+ 
+/**************************************************************************************************/
+/* data chunks */
+
+void md_data_pinit(md_data_t *d, apr_size_t len, apr_pool_t *p)
+{
+    md_data_null(d);
+    d->data = apr_pcalloc(p, len);
+    d->len = len;
+}
+
+md_data_t *md_data_pmake(apr_size_t len, apr_pool_t *p)
+{
+    md_data_t *d;
+    
+    d = apr_palloc(p, sizeof(*d));
+    md_data_pinit(d, len, p);
+    return d;
+}
+
+void md_data_init(md_data_t *d, const char *data, apr_size_t len)
+{
+    md_data_null(d);
+    d->len = len;
+    d->data = data;
+}
+
+void md_data_init_str(md_data_t *d, const char *str)
+{
+    md_data_init(d, str, strlen(str));
+}
+
+void md_data_null(md_data_t *d)
+{
+    memset(d, 0, sizeof(*d));
+}
+
+void md_data_clear(md_data_t *d)
+{
+    if (d) {
+        if (d->data && d->free_data) d->free_data((void*)d->data);
+        memset(d, 0, sizeof(*d));
+    }
+}
+
+md_data_t *md_data_make_pcopy(apr_pool_t *p, const char *data, apr_size_t len)
+{
+    md_data_t *d;
+
+    d = apr_palloc(p, sizeof(*d));
+    d->len = len;
+    d->data = len? apr_pmemdup(p, data, len) : NULL;
+    return d;
+}
+
+apr_status_t md_data_assign_copy(md_data_t *dest, const char *src, apr_size_t src_len)
+{
+    md_data_clear(dest);
+    if (src && src_len) {
+        dest->data = malloc(src_len);
+        if (!dest->data) return APR_ENOMEM;
+        memcpy((void*)dest->data, src, src_len);
+        dest->len = src_len;
+        dest->free_data = free;
+    }
+    return APR_SUCCESS;
+}
+
+void md_data_assign_pcopy(md_data_t *dest, const char *src, apr_size_t src_len, apr_pool_t *p)
+{
+    md_data_clear(dest);
+    dest->data = (src && src_len)? apr_pmemdup(p, src, src_len) : NULL;
+    dest->len = dest->data? src_len : 0;
+}
+
+static const char * const hex_const[] = {
+    "00", "01", "02", "03", "04", "05", "06", "07", "08", "09", "0a", "0b", "0c", "0d", "0e", "0f", 
+    "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "1a", "1b", "1c", "1d", "1e", "1f", 
+    "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "2a", "2b", "2c", "2d", "2e", "2f", 
+    "30", "31", "32", "33", "34", "35", "36", "37", "38", "39", "3a", "3b", "3c", "3d", "3e", "3f", 
+    "40", "41", "42", "43", "44", "45", "46", "47", "48", "49", "4a", "4b", "4c", "4d", "4e", "4f", 
+    "50", "51", "52", "53", "54", "55", "56", "57", "58", "59", "5a", "5b", "5c", "5d", "5e", "5f", 
+    "60", "61", "62", "63", "64", "65", "66", "67", "68", "69", "6a", "6b", "6c", "6d", "6e", "6f", 
+    "70", "71", "72", "73", "74", "75", "76", "77", "78", "79", "7a", "7b", "7c", "7d", "7e", "7f", 
+    "80", "81", "82", "83", "84", "85", "86", "87", "88", "89", "8a", "8b", "8c", "8d", "8e", "8f", 
+    "90", "91", "92", "93", "94", "95", "96", "97", "98", "99", "9a", "9b", "9c", "9d", "9e", "9f", 
+    "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", "a8", "a9", "aa", "ab", "ac", "ad", "ae", "af", 
+    "b0", "b1", "b2", "b3", "b4", "b5", "b6", "b7", "b8", "b9", "ba", "bb", "bc", "bd", "be", "bf", 
+    "c0", "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "ca", "cb", "cc", "cd", "ce", "cf", 
+    "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", "d8", "d9", "da", "db", "dc", "dd", "de", "df", 
+    "e0", "e1", "e2", "e3", "e4", "e5", "e6", "e7", "e8", "e9", "ea", "eb", "ec", "ed", "ee", "ef", 
+    "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", "f8", "f9", "fa", "fb", "fc", "fd", "fe", "ff", 
+};
+
+apr_status_t md_data_to_hex(const char **phex, char separator,
+                            apr_pool_t *p, const md_data_t *data)
+{
+    char *hex, *cp;
+    const char * x;
+    unsigned int i;
+    
+    cp = hex = apr_pcalloc(p, ((separator? 3 : 2) * data->len) + 1);
+    if (!hex) {
+        *phex = NULL;
+        return APR_ENOMEM;
+    }
+    for (i = 0; i < data->len; ++i) {
+        x = hex_const[(unsigned char)data->data[i]];
+        if (i && separator) *cp++ = separator;
+        *cp++ = x[0];
+        *cp++ = x[1];
+    }
+    *phex = hex;
+    return APR_SUCCESS;
+}
+
+/**************************************************************************************************/
+/* generic arrays */
+
+int md_array_remove_at(struct apr_array_header_t *a, int idx)
+{
+    char *ps, *pe;
+
+    if (idx < 0 || idx >= a->nelts) return 0;
+    if (idx+1 == a->nelts) {
+        --a->nelts;
+    }
+    else {
+        ps = (a->elts + (idx * a->elt_size));
+        pe = ps + a->elt_size;
+        memmove(ps, pe, (size_t)((a->nelts - (idx+1)) * a->elt_size));
+        --a->nelts;
+    }
+    return 1;
+}
+
+int md_array_remove(struct apr_array_header_t *a, void *elem)
+{
+    int i, n, m;
+    void **pe;
+    
+    assert(sizeof(void*) == a->elt_size);
+    n = i = 0;
+    while (i < a->nelts) {
+        pe = &APR_ARRAY_IDX(a, i, void*);
+        if (*pe == elem) {
+            m = a->nelts - (i+1);
+            if (m > 0) memmove(pe, pe+1, (unsigned)m*sizeof(void*));
+            a->nelts--;
+            n++;
+            continue;
+        }
+        ++i;
+    }
+    return n;
+}
+
+/**************************************************************************************************/
+/* string related */
+
+int md_array_is_empty(const struct apr_array_header_t *array)
+{
+    return (array == NULL) || (array->nelts == 0);
+}
+
+char *md_util_str_tolower(char *s)
+{
+    char *orig = s;
+    while (*s) {
+        *s = (char)apr_tolower(*s);
+        ++s;
+    }
+    return orig;
+}
+
+int md_array_str_index(const apr_array_header_t *array, const char *s, 
+                       int start, int case_sensitive)
+{
+    if (start >= 0) {
+        int i;
+        
+        for (i = start; i < array->nelts; i++) {
+            const char *p = APR_ARRAY_IDX(array, i, const char *);
+            if ((case_sensitive && !strcmp(p, s))
+                || (!case_sensitive && !apr_strnatcasecmp(p, s))) {
+                return i;
+            }
+        }
+    }
+    
+    return -1;
+}
+
+int md_array_str_eq(const struct apr_array_header_t *a1, 
+                    const struct apr_array_header_t *a2, int case_sensitive)
+{
+    int i;
+    const char *s1, *s2;
+    
+    if (a1 == a2) return 1;
+    if (!a1 || !a2) return 0;
+    if (a1->nelts != a2->nelts) return 0;
+    for (i = 0; i < a1->nelts; ++i) {
+        s1 = APR_ARRAY_IDX(a1, i, const char *);
+        s2 = APR_ARRAY_IDX(a2, i, const char *);
+        if ((case_sensitive && strcmp(s1, s2))
+            || (!case_sensitive && apr_strnatcasecmp(s1, s2))) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+apr_array_header_t *md_array_str_clone(apr_pool_t *p, apr_array_header_t *src)
+{
+    apr_array_header_t *dest = apr_array_make(p, src->nelts, sizeof(const char*));
+    if (dest) {
+        int i;
+        for (i = 0; i < src->nelts; i++) {
+            const char *s = APR_ARRAY_IDX(src, i, const char *);
+            APR_ARRAY_PUSH(dest, const char *) = apr_pstrdup(p, s); 
+        }
+    }
+    return dest;
+}
+
+struct apr_array_header_t *md_array_str_compact(apr_pool_t *p, struct apr_array_header_t *src,
+                                                int case_sensitive)
+{
+    apr_array_header_t *dest = apr_array_make(p, src->nelts, sizeof(const char*));
+    if (dest) {
+        const char *s;
+        int i;
+        for (i = 0; i < src->nelts; ++i) {
+            s = APR_ARRAY_IDX(src, i, const char *);
+            if (md_array_str_index(dest, s, 0, case_sensitive) < 0) {
+                APR_ARRAY_PUSH(dest, char *) = md_util_str_tolower(apr_pstrdup(p, s));
+            }
+        }
+    }
+    return dest;
+}
+
+apr_array_header_t *md_array_str_remove(apr_pool_t *p, apr_array_header_t *src, 
+                                        const char *exclude, int case_sensitive)
+{
+    apr_array_header_t *dest = apr_array_make(p, src->nelts, sizeof(const char*));
+    if (dest) {
+        int i;
+        for (i = 0; i < src->nelts; i++) {
+            const char *s = APR_ARRAY_IDX(src, i, const char *);
+            if (!exclude 
+                || (case_sensitive && strcmp(exclude, s))
+                || (!case_sensitive && apr_strnatcasecmp(exclude, s))) {
+                APR_ARRAY_PUSH(dest, const char *) = apr_pstrdup(p, s); 
+            }
+        }
+    }
+    return dest;
+}
+
+int md_array_str_add_missing(apr_array_header_t *dest, apr_array_header_t *src, int case_sensitive)
+{
+    int i, added = 0;
+    for (i = 0; i < src->nelts; i++) {
+        const char *s = APR_ARRAY_IDX(src, i, const char *);
+        if (md_array_str_index(dest, s, 0, case_sensitive) < 0) {
+            APR_ARRAY_PUSH(dest, const char *) = s;
+            ++added; 
+        }
+    }
+    return added;
+}
+
+/**************************************************************************************************/
+/* file system related */
+
+apr_status_t md_util_fopen(FILE **pf, const char *fn, const char *mode)
+{
+    *pf = fopen(fn, mode);
+    if (*pf == NULL) {
+        return errno;
+    }
+
+    return APR_SUCCESS;
+}
+
+apr_status_t md_util_fcreatex(apr_file_t **pf, const char *fn, 
+                              apr_fileperms_t perms, apr_pool_t *p)
+{
+    apr_status_t rv;
+    rv = apr_file_open(pf, fn, (APR_FOPEN_WRITE|APR_FOPEN_CREATE|APR_FOPEN_EXCL),
+                       perms, p);
+    if (APR_SUCCESS == rv) {
+        /* See <https://github.com/icing/mod_md/issues/117>
+         * Some people set umask 007 to deny all world read/writability to files
+         * created by apache. While this is a noble effort, we need the store files
+         * to have the permissions as specified. */
+        rv = apr_file_perms_set(fn, perms);
+        if (APR_STATUS_IS_ENOTIMPL(rv)) {
+            rv = APR_SUCCESS;
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_util_is_dir(const char *path, apr_pool_t *pool)
+{
+    apr_finfo_t info;
+    apr_status_t rv = apr_stat(&info, path, APR_FINFO_TYPE, pool);
+    if (rv == APR_SUCCESS) {
+        rv = (info.filetype == APR_DIR)? APR_SUCCESS : APR_EINVAL;
+    }
+    return rv;
+}
+
+apr_status_t md_util_is_file(const char *path, apr_pool_t *pool)
+{
+    apr_finfo_t info;
+    apr_status_t rv = apr_stat(&info, path, APR_FINFO_TYPE, pool);
+    if (rv == APR_SUCCESS) {
+        rv = (info.filetype == APR_REG)? APR_SUCCESS : APR_EINVAL;
+    }
+    return rv;
+}
+
+apr_status_t md_util_is_unix_socket(const char *path, apr_pool_t *pool)
+{
+    apr_finfo_t info;
+    apr_status_t rv = apr_stat(&info, path, APR_FINFO_TYPE, pool);
+    if (rv == APR_SUCCESS) {
+        rv = (info.filetype == APR_SOCK)? APR_SUCCESS : APR_EINVAL;
+    }
+    return rv;
+}
+
+int md_file_exists(const char *fname, apr_pool_t *p)
+{
+    return (fname && *fname && APR_SUCCESS == md_util_is_file(fname, p));
+}
+
+apr_status_t md_util_path_merge(const char **ppath, apr_pool_t *p, ...)
+{
+    const char *segment, *path;
+    va_list ap;
+    apr_status_t rv = APR_SUCCESS;
+    
+    va_start(ap, p);
+    path = va_arg(ap, char *);
+    while (path && APR_SUCCESS == rv && (segment = va_arg(ap, char *))) {
+        rv = apr_filepath_merge((char **)&path, path, segment, APR_FILEPATH_SECUREROOT , p);
+    }
+    va_end(ap);
+    
+    *ppath = (APR_SUCCESS == rv)? (path? path : "") : NULL;
+    return rv;
+}
+
+apr_status_t md_util_freplace(const char *fpath, apr_fileperms_t perms, apr_pool_t *p, 
+                              md_util_file_cb *write_cb, void *baton)
+{
+    apr_status_t rv = APR_EEXIST;
+    apr_file_t *f;
+    const char *tmp;
+    int i, max;
+    
+    tmp = apr_psprintf(p, "%s.tmp", fpath);
+    i = 0; max = 20;
+creat:
+    while (i < max && APR_EEXIST == (rv = md_util_fcreatex(&f, tmp, perms, p))) {
+        ++i;
+        apr_sleep(apr_time_from_msec(50));
+    } 
+    if (APR_EEXIST == rv 
+        && APR_SUCCESS == (rv = apr_file_remove(tmp, p))
+        && max <= 20) {
+        max *= 2;
+        goto creat;
+    }
+    
+    if (APR_SUCCESS == rv) {
+        rv = write_cb(baton, f, p);
+        apr_file_close(f);
+        
+        if (APR_SUCCESS == rv) {
+            rv = apr_file_rename(tmp, fpath, p);
+            if (APR_SUCCESS != rv) {
+                apr_file_remove(tmp, p);
+            }
+        }
+    }
+    return rv;
+}                            
+
+/**************************************************************************************************/
+/* text files */
+
+apr_status_t md_text_fread8k(const char **ptext, apr_pool_t *p, const char *fpath)
+{
+    apr_status_t rv;
+    apr_file_t *f;
+    char buffer[8 * 1024];
+
+    *ptext = NULL;
+    if (APR_SUCCESS == (rv = apr_file_open(&f, fpath, APR_FOPEN_READ, 0, p))) {
+        apr_size_t blen = sizeof(buffer)/sizeof(buffer[0]) - 1;
+        rv = apr_file_read_full(f, buffer, blen, &blen);
+        if (APR_SUCCESS == rv || APR_STATUS_IS_EOF(rv)) {
+            *ptext = apr_pstrndup(p, buffer, blen);
+            rv = APR_SUCCESS;
+        }
+        apr_file_close(f);
+    }
+    return rv;
+}
+
+static apr_status_t write_text(void *baton, struct apr_file_t *f, apr_pool_t *p)
+{
+    const char *text = baton;
+    apr_size_t len = strlen(text);
+    
+    (void)p;
+    return apr_file_write_full(f, text, len, &len);
+}
+
+apr_status_t md_text_fcreatex(const char *fpath, apr_fileperms_t perms, 
+                              apr_pool_t *p, const char *text)
+{
+    apr_status_t rv;
+    apr_file_t *f;
+    
+    rv = md_util_fcreatex(&f, fpath, perms, p);
+    if (APR_SUCCESS == rv) {
+        rv = write_text((void*)text, f, p);
+        apr_file_close(f);
+        /* See <https://github.com/icing/mod_md/issues/117>: when a umask
+         * is set, files need to be assigned permissions explicitly.
+         * Otherwise, as in the issues reported, it will break our access model. */
+        rv = apr_file_perms_set(fpath, perms);
+        if (APR_STATUS_IS_ENOTIMPL(rv)) {
+            rv = APR_SUCCESS;
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_text_freplace(const char *fpath, apr_fileperms_t perms, 
+                              apr_pool_t *p, const char *text)
+{
+    return md_util_freplace(fpath, perms, p, write_text, (void*)text);
+}
+
+typedef struct {
+    const char *path;
+    apr_array_header_t *patterns;
+    int follow_links;
+    void *baton;
+    md_util_fdo_cb *cb;
+} md_util_fwalk_t;
+
+static apr_status_t rm_recursive(const char *fpath, apr_pool_t *p, int max_level)
+{
+    apr_finfo_t info;
+    apr_status_t rv;
+    const char *npath;
+    
+    if (APR_SUCCESS != (rv = apr_stat(&info, fpath, (APR_FINFO_TYPE|APR_FINFO_LINK), p))) {
+        return rv;
+    }
+    
+    if (info.filetype == APR_DIR) {
+        if (max_level > 0) {
+            apr_dir_t *d;
+            
+            if (APR_SUCCESS == (rv = apr_dir_open(&d, fpath, p))) {
+            
+                while (APR_SUCCESS == rv && 
+                       APR_SUCCESS == (rv = apr_dir_read(&info, APR_FINFO_TYPE, d))) {
+                    if (!strcmp(".", info.name) || !strcmp("..", info.name)) {
+                        continue;
+                    }
+                    
+                    rv = md_util_path_merge(&npath, p, fpath, info.name, NULL);
+                    if (APR_SUCCESS == rv) {
+                        rv = rm_recursive(npath, p, max_level - 1);
+                    }
+                }
+                apr_dir_close(d);
+                if (APR_STATUS_IS_ENOENT(rv)) {
+                    rv = APR_SUCCESS;
+                }
+            }
+        }
+        if (APR_SUCCESS == rv) {
+            rv = apr_dir_remove(fpath, p);
+        }
+    }
+    else {
+        rv = apr_file_remove(fpath, p);
+    }
+    return rv;
+}
+
+static apr_status_t prm_recursive(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    int max_level = va_arg(ap, int);
+    
+    (void)p;
+    return rm_recursive(baton, ptemp, max_level); 
+}
+
+apr_status_t md_util_rm_recursive(const char *fpath, apr_pool_t *p, int max_level)
+{
+    return md_util_pool_vdo(prm_recursive, (void*)fpath, p, max_level, NULL);
+}
+
+static apr_status_t match_and_do(md_util_fwalk_t *ctx, const char *path, int depth, 
+                                 apr_pool_t *p, apr_pool_t *ptemp)
+{
+    apr_status_t rv = APR_SUCCESS;
+    const char *pattern, *npath;
+    apr_dir_t *d;
+    apr_finfo_t finfo;
+    int ndepth = depth + 1;
+    apr_int32_t wanted = (APR_FINFO_TYPE);
+
+    if (depth >= ctx->patterns->nelts) {
+        return APR_SUCCESS;
+    }
+    pattern = APR_ARRAY_IDX(ctx->patterns, depth, const char *);
+    
+    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, ptemp, "match_and_do "
+                  "path=%s depth=%d pattern=%s", path, depth, pattern);
+    rv = apr_dir_open(&d, path, ptemp);
+    if (APR_SUCCESS != rv) {
+        return rv;
+    }
+    
+    while (APR_SUCCESS == (rv = apr_dir_read(&finfo, wanted, d))) {
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, ptemp, "match_and_do "
+                      "candidate=%s", finfo.name);
+        if (!strcmp(".", finfo.name) || !strcmp("..", finfo.name)) {
+            continue;
+        } 
+        if (APR_SUCCESS == apr_fnmatch(pattern, finfo.name, 0)) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, ptemp, "match_and_do "
+                          "candidate=%s matches pattern", finfo.name);
+            if (ndepth < ctx->patterns->nelts) {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, ptemp, "match_and_do "
+                              "need to go deeper");
+                if (APR_DIR == finfo.filetype) { 
+                    /* deeper and deeper, irgendwo in der tiefe leuchtet ein licht */
+                    rv = md_util_path_merge(&npath, ptemp, path, finfo.name, NULL);
+                    if (APR_SUCCESS == rv) {
+                        rv = match_and_do(ctx, npath, ndepth, p, ptemp);
+                    }
+                }
+            }
+            else {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE4, 0, ptemp, "match_and_do "
+                              "invoking inspector on name=%s", finfo.name);
+                rv = ctx->cb(ctx->baton, p, ptemp, path, finfo.name, finfo.filetype);
+            }
+        }
+        if (APR_SUCCESS != rv) {
+            break;
+        }
+    }
+
+    if (APR_STATUS_IS_ENOENT(rv)) {
+        rv = APR_SUCCESS;
+    }
+
+    apr_dir_close(d);
+    return rv;
+}
+
+static apr_status_t files_do_start(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap)
+{
+    md_util_fwalk_t *ctx = baton;
+    const char *segment;
+
+    ctx->patterns = apr_array_make(ptemp, 5, sizeof(const char*));
+    
+    segment = va_arg(ap, char *);
+    while (segment) {
+        APR_ARRAY_PUSH(ctx->patterns, const char *) = segment;
+        segment = va_arg(ap, char *);
+    }
+    
+    return match_and_do(ctx, ctx->path, 0, p, ptemp);
+}
+
+apr_status_t md_util_files_do(md_util_fdo_cb *cb, void *baton, apr_pool_t *p,
+                              const char *path, ...)
+{
+    apr_status_t rv;
+    va_list ap;
+    md_util_fwalk_t ctx;
+
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.path = path;
+    ctx.follow_links = 1;
+    ctx.cb = cb;
+    ctx.baton = baton;
+    
+    va_start(ap, path);
+    rv = pool_vado(files_do_start, &ctx, p, ap);
+    va_end(ap);
+    
+    return rv;
+}
+
+static apr_status_t tree_do(void *baton, apr_pool_t *p, apr_pool_t *ptemp, const char *path)
+{
+    md_util_fwalk_t *ctx = baton;
+
+    apr_status_t rv = APR_SUCCESS;
+    const char *name, *fpath;
+    apr_filetype_e ftype;
+    apr_dir_t *d;
+    apr_int32_t wanted = APR_FINFO_TYPE;
+    apr_finfo_t finfo;
+
+    if (APR_SUCCESS == (rv = apr_dir_open(&d, path, ptemp))) {
+        while (APR_SUCCESS == (rv = apr_dir_read(&finfo, wanted, d))) {
+            name = finfo.name;
+            if (!strcmp(".", name) || !strcmp("..", name)) {
+                continue;
+            }
+
+            fpath = NULL;
+            ftype = finfo.filetype;
+            
+            if (APR_LNK == ftype && ctx->follow_links) {
+                rv = md_util_path_merge(&fpath, ptemp, path, name, NULL);
+                if (APR_SUCCESS == rv) {
+                    rv = apr_stat(&finfo, ctx->path, wanted, ptemp);
+                }
+            }
+            
+            if (APR_DIR == finfo.filetype) {
+                if (!fpath) {
+                    rv = md_util_path_merge(&fpath, ptemp, path, name, NULL);
+                }
+                if (APR_SUCCESS == rv) {
+                    rv = tree_do(ctx, p, ptemp, fpath);
+                    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, ptemp, "dir cb(%s/%s)", 
+                                  path, name);
+                    rv = ctx->cb(ctx->baton, p, ptemp, path, name, ftype);
+                }
+            }
+            else {
+                md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, rv, ptemp, "file cb(%s/%s)", 
+                              path, name);
+                rv = ctx->cb(ctx->baton, p, ptemp, path, name, finfo.filetype);
+            }
+        }
+
+        apr_dir_close(d);
+        
+        if (APR_STATUS_IS_ENOENT(rv)) {
+            rv = APR_SUCCESS;
+        }
+    }
+    return rv;
+}
+
+static apr_status_t tree_start_do(void *baton, apr_pool_t *p, apr_pool_t *ptemp)
+{
+    md_util_fwalk_t *ctx = baton;
+    apr_finfo_t info;
+    apr_status_t rv;
+    apr_int32_t wanted = ctx->follow_links? APR_FINFO_TYPE : (APR_FINFO_TYPE|APR_FINFO_LINK);
+    
+    rv = apr_stat(&info, ctx->path, wanted, ptemp);
+    if (rv == APR_SUCCESS) {
+        switch (info.filetype) {
+            case APR_DIR:
+                rv = tree_do(ctx, p, ptemp, ctx->path);
+                break;
+            default:
+                rv = APR_EINVAL;
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_util_tree_do(md_util_fdo_cb *cb, void *baton, apr_pool_t *p, 
+                             const char *path, int follow_links)
+{
+    apr_status_t rv;
+    md_util_fwalk_t ctx;
+
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.path = path;
+    ctx.follow_links = follow_links;
+    ctx.cb = cb;
+    ctx.baton = baton;
+    
+    rv = md_util_pool_do(tree_start_do, &ctx, p);
+    
+    return rv;
+}
+
+static apr_status_t rm_cb(void *baton, apr_pool_t *p, apr_pool_t *ptemp, 
+                          const char *path, const char *name, apr_filetype_e ftype)
+{
+    apr_status_t rv;
+    const char *fpath;
+    
+    (void)baton;
+    (void)p;
+    rv = md_util_path_merge(&fpath, ptemp, path, name, NULL);
+    if (APR_SUCCESS == rv) {
+        if (APR_DIR == ftype) {
+            rv = apr_dir_remove(fpath, ptemp);
+        }
+        else {
+            rv = apr_file_remove(fpath, ptemp);
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_util_ftree_remove(const char *path, apr_pool_t *p)
+{
+    apr_status_t rv = md_util_tree_do(rm_cb, NULL, p, path, 0);
+    if (APR_SUCCESS == rv) {
+        rv = apr_dir_remove(path, p);
+    }
+    return rv;
+}
+
+/* DNS name checks ********************************************************************************/
+
+int md_dns_is_name(apr_pool_t *p, const char *hostname, int need_fqdn)
+{
+    char c, last = 0;
+    const char *cp = hostname;
+    int dots = 0;
+    
+    /* Since we use the names in certificates, we need pure ASCII domain names
+     * and IDN need to be converted to unicode. */
+    while ((c = *cp++)) {
+        switch (c) {
+            case '.':
+                if (last == '.') {
+                    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, p, "dns name with ..: %s", 
+                                  hostname);
+                    return 0;
+                }
+                ++dots;
+                break;
+            case '-':
+                break;
+            default:
+                if (!apr_isalnum(c)) {
+                    md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, p, "dns invalid char %c: %s", 
+                                  c, hostname);
+                    return 0;
+                }
+                break;
+        }
+        last = c;
+    }
+    
+    if (last == '.') { /* DNS names may end with '.' */
+        --dots;
+    }
+    if (need_fqdn && dots <= 0) { /* do not accept just top level domains */
+        md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, p, "not a FQDN: %s", hostname);
+        return 0;
+    }
+    return 1; /* empty string not allowed */
+}
+
+int md_dns_is_wildcard(apr_pool_t *p, const char *domain)
+{
+    if (domain[0] != '*' || domain[1] != '.') return 0;
+    return md_dns_is_name(p, domain+2, 1);
+}
+
+int md_dns_matches(const char *pattern, const char *domain)
+{
+    const char *s;
+    
+    if (!apr_strnatcasecmp(pattern, domain)) return 1;
+    if (pattern[0] == '*' && pattern[1] == '.') {
+        s = strchr(domain, '.');
+        if (s && !apr_strnatcasecmp(pattern+1, s)) return 1;
+    }
+    return 0;
+}
+
+apr_array_header_t *md_dns_make_minimal(apr_pool_t *p, apr_array_header_t *domains)
+{
+    apr_array_header_t *minimal;
+    const char *domain, *pattern;
+    int i, j, duplicate;
+    
+    minimal = apr_array_make(p, domains->nelts, sizeof(const char *));
+    for (i = 0; i < domains->nelts; ++i) {
+        domain = APR_ARRAY_IDX(domains, i, const char*);
+        duplicate = 0;
+        /* is it matched in minimal already? */
+        for (j = 0; j < minimal->nelts; ++j) {
+            pattern = APR_ARRAY_IDX(minimal, j, const char*);
+            if (md_dns_matches(pattern, domain)) {
+                duplicate = 1;
+                break;
+            }
+        }
+        if (!duplicate) {
+            if (!md_dns_is_wildcard(p, domain)) {
+                /* plain name, will we see a wildcard that replaces it? */
+                for (j = i+1; j < domains->nelts; ++j) {
+                    pattern = APR_ARRAY_IDX(domains, j, const char*);
+                    if (md_dns_is_wildcard(p, pattern) && md_dns_matches(pattern, domain)) {
+                        duplicate = 1;
+                        break;
+                    }
+                }
+            }
+            if (!duplicate) {
+                APR_ARRAY_PUSH(minimal, const char *) = domain; 
+            }
+        }
+    }
+    return minimal;
+}
+
+int md_dns_domains_match(const apr_array_header_t *domains, const char *name)
+{
+    const char *domain;
+    int i;
+    
+    for (i = 0; i < domains->nelts; ++i) {
+        domain = APR_ARRAY_IDX(domains, i, const char*);
+        if (md_dns_matches(domain, name)) return 1;
+    }
+    return 0;
+}
+
+const char *md_util_schemify(apr_pool_t *p, const char *s, const char *def_scheme)
+{
+    const char *cp = s;
+    while (*cp) {
+        if (*cp == ':') {
+            /* could be an url scheme, leave unchanged */
+            return s;
+        }
+        else if (!apr_isalnum(*cp)) {
+            break;
+        }
+        ++cp;
+    }
+    return apr_psprintf(p, "%s:%s", def_scheme, s);
+}
+
+static apr_status_t uri_check(apr_uri_t *uri_parsed, apr_pool_t *p, 
+                              const char *uri, const char **perr)
+{
+    const char *s, *err = NULL;
+    apr_status_t rv;
+    
+    if (APR_SUCCESS != (rv = apr_uri_parse(p, uri, uri_parsed))) {
+        err = "not an uri";
+    }
+    else if (uri_parsed->scheme) {
+        if (strlen(uri_parsed->scheme) + 1 >= strlen(uri)) {
+            err = "missing uri identifier";
+        }
+        else if (!strncmp("http", uri_parsed->scheme, 4)) {
+            if (!uri_parsed->hostname) {
+                err = "missing hostname";
+            }
+            else if (!md_dns_is_name(p, uri_parsed->hostname, 0)) {
+                err = "invalid hostname";
+            }
+            if (uri_parsed->port_str 
+                && (!apr_isdigit(uri_parsed->port_str[0])
+                || uri_parsed->port == 0
+                || uri_parsed->port > 65353)) {
+                err = "invalid port";
+            }
+        }
+        else if (!strcmp("mailto", uri_parsed->scheme)) {
+            s = strchr(uri, '@');
+            if (!s) {
+                err = "missing @";
+            }
+            else if (strchr(s+1, '@')) {
+                err = "duplicate @";
+            }
+            else if (s == uri + strlen(uri_parsed->scheme) + 1) {
+                err = "missing local part";
+            }
+            else if (s == (uri + strlen(uri)-1)) {
+                err = "missing hostname";
+            }
+            else if (strstr(uri, "..")) {
+                err = "double period";
+            }
+        }
+    }
+    if (strchr(uri, ' ') || strchr(uri, '\t') ) {
+        err = "whitespace in uri";
+    }
+    
+    if (err) {
+        rv = APR_EINVAL;
+    }
+    *perr = err;
+    return rv;
+}
+
+apr_status_t md_util_abs_uri_check(apr_pool_t *p, const char *uri, const char **perr)
+{
+    apr_uri_t uri_parsed;
+    apr_status_t rv;
+
+    if (APR_SUCCESS == (rv = uri_check(&uri_parsed, p, uri, perr))) {
+        if (!uri_parsed.scheme) {
+            *perr = "missing uri scheme";
+            return APR_EINVAL;
+        }
+    }
+    return rv;
+}
+
+apr_status_t md_util_abs_http_uri_check(apr_pool_t *p, const char *uri, const char **perr)
+{
+    apr_uri_t uri_parsed;
+    apr_status_t rv;
+
+    if (APR_SUCCESS == (rv = uri_check(&uri_parsed, p, uri, perr))) {
+        if (!uri_parsed.scheme) {
+            *perr = "missing uri scheme";
+            return APR_EINVAL;
+        }
+        if (apr_strnatcasecmp("http", uri_parsed.scheme) 
+            && apr_strnatcasecmp("https", uri_parsed.scheme)) {
+            *perr = "uri scheme must be http or https";
+            return APR_EINVAL;
+        }
+    }
+    return rv;
+}
+
+/* try and retry for a while **********************************************************************/
+
+apr_status_t md_util_try(md_util_try_fn *fn, void *baton, int ignore_errs, 
+                         apr_interval_time_t timeout, apr_interval_time_t start_delay, 
+                         apr_interval_time_t max_delay, int backoff)
+{
+    apr_status_t rv;
+    apr_time_t now = apr_time_now();
+    apr_time_t giveup = now + timeout;
+    apr_interval_time_t nap_duration = start_delay? start_delay : apr_time_from_msec(100);
+    apr_interval_time_t nap_max = max_delay? max_delay : apr_time_from_sec(10);
+    apr_interval_time_t left;
+    int i = 0;
+    
+    while (1) {
+        if (APR_SUCCESS == (rv = fn(baton, i++))) {
+            break;
+        }
+        else if (!APR_STATUS_IS_EAGAIN(rv) && !ignore_errs) {
+            break;
+        }
+        
+        now = apr_time_now();
+        if (now > giveup) {
+            rv = APR_TIMEUP;
+            break;
+        }
+        
+        left = giveup - now;
+        if (nap_duration > left) {
+            nap_duration = left;
+        }
+        if (nap_duration > nap_max) {
+            nap_duration = nap_max;
+        }
+        
+        apr_sleep(nap_duration);
+        if (backoff) {
+            nap_duration *= 2;
+        } 
+    }
+    return rv;
+}
+
+/* execute process ********************************************************************************/
+
+apr_status_t md_util_exec(apr_pool_t *p, const char *cmd, const char * const *argv,
+                          apr_array_header_t *env, int *exit_code)
+{
+    apr_status_t rv;
+    apr_procattr_t *procattr;
+    apr_proc_t *proc;
+    apr_exit_why_e ewhy;
+    const char * const *envp = NULL;
+    char buffer[1024];
+    
+    *exit_code = 0;
+    if (!(proc = apr_pcalloc(p, sizeof(*proc)))) {
+        return APR_ENOMEM;
+    }
+    if (env && env->nelts > 0) {
+        apr_array_header_t *nenv;
+        
+        nenv = apr_array_copy(p, env);
+        APR_ARRAY_PUSH(nenv, const char *) = NULL;
+        envp = (const char * const *)nenv->elts;
+    }
+    if (   APR_SUCCESS == (rv = apr_procattr_create(&procattr, p))
+        && APR_SUCCESS == (rv = apr_procattr_io_set(procattr, APR_NO_FILE, 
+                                                    APR_NO_PIPE, APR_FULL_BLOCK))
+        && APR_SUCCESS == (rv = apr_procattr_cmdtype_set(procattr, APR_PROGRAM))
+        && APR_SUCCESS == (rv = apr_proc_create(proc, cmd, argv, envp, procattr, p))) {
+        
+        /* read stderr and log on INFO for possible fault analysis. */
+        while(APR_SUCCESS == (rv = apr_file_gets(buffer, sizeof(buffer)-1, proc->err))) {
+            md_log_perror(MD_LOG_MARK, MD_LOG_INFO, 0, p, "cmd(%s) stderr: %s", cmd, buffer);
+        }
+        if (!APR_STATUS_IS_EOF(rv)) goto out;
+        apr_file_close(proc->err);
+        
+        if (APR_CHILD_DONE == (rv = apr_proc_wait(proc, exit_code, &ewhy, APR_WAIT))) {
+            /* let's not dwell on exit stati, but core should signal something's bad */
+            if (*exit_code > 127 || APR_PROC_SIGNAL_CORE == ewhy) {
+                return APR_EINCOMPLETE;
+            }
+            return APR_SUCCESS;
+        }
+    }
+out:
+    return rv;
+}
+
+/* base64 url encoding ****************************************************************************/
+
+#define N6 (unsigned int)-1
+
+static const unsigned int BASE64URL_UINT6[] = {
+/*   0   1   2   3   4   5   6   7   8   9   a   b   c   d   e   f        */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, /*  0 */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, /*  1 */ 
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, 62, N6, N6, /*  2 */
+    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, N6, N6, N6, N6, N6, N6, /*  3 */ 
+    N6, 0,  1,  2,  3,  4,  5,  6,   7,  8,  9, 10, 11, 12, 13, 14, /*  4 */
+    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, N6, N6, N6, N6, 63, /*  5 */
+    N6, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /*  6 */
+    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, N6, N6, N6, N6, N6, /*  7 */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, /*  8 */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, /*  9 */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, /*  a */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, /*  b */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, /*  c */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, /*  d */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, /*  e */
+    N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6, N6  /*  f */
+};
+static const unsigned char BASE64URL_CHARS[] = {
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', /*  0 -  9 */
+    'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', /* 10 - 19 */
+    'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', /* 20 - 29 */
+    'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', /* 30 - 39 */
+    'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', /* 40 - 49 */
+    'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', /* 50 - 59 */
+    '8', '9', '-', '_', ' ', ' ', ' ', ' ', ' ', ' ', /* 60 - 69 */
+};
+
+#define BASE64URL_CHAR(x)    BASE64URL_CHARS[ (unsigned int)(x) & 0x3fu ]
+   
+apr_size_t md_util_base64url_decode(md_data_t *decoded, const char *encoded, 
+                                    apr_pool_t *pool)
+{
+    const unsigned char *e = (const unsigned char *)encoded;
+    const unsigned char *p = e;
+    unsigned char *d;
+    unsigned int n;
+    long len, mlen, remain, i;
+    
+    while (*p && BASE64URL_UINT6[ *p ] != N6) {
+        ++p;
+    }
+    len = (int)(p - e);
+    mlen = (len/4)*4;
+    decoded->data = apr_pcalloc(pool, (apr_size_t)len + 1);
+    
+    i = 0;
+    d = (unsigned char*)decoded->data;
+    for (; i < mlen; i += 4) {
+        n = ((BASE64URL_UINT6[ e[i+0] ] << 18) +
+             (BASE64URL_UINT6[ e[i+1] ] << 12) +
+             (BASE64URL_UINT6[ e[i+2] ] << 6) +
+             (BASE64URL_UINT6[ e[i+3] ]));
+        *d++ = (unsigned char)(n >> 16);
+        *d++ = (unsigned char)(n >> 8 & 0xffu);
+        *d++ = (unsigned char)(n & 0xffu);
+    }
+    remain = len - mlen;
+    switch (remain) {
+        case 2:
+            n = ((BASE64URL_UINT6[ e[mlen+0] ] << 18) +
+                 (BASE64URL_UINT6[ e[mlen+1] ] << 12));
+            *d++ = (unsigned char)(n >> 16);
+            remain = 1;
+            break;
+        case 3:
+            n = ((BASE64URL_UINT6[ e[mlen+0] ] << 18) +
+                 (BASE64URL_UINT6[ e[mlen+1] ] << 12) +
+                 (BASE64URL_UINT6[ e[mlen+2] ] << 6));
+            *d++ = (unsigned char)(n >> 16);
+            *d++ = (unsigned char)(n >> 8 & 0xffu);
+            remain = 2;
+            break;
+        default: /* do nothing */
+            break;
+    }
+    decoded->len = (apr_size_t)(mlen/4*3 + remain);
+    return decoded->len; 
+}
+
+const char *md_util_base64url_encode(const md_data_t *data, apr_pool_t *pool)
+{
+    int i, len = (int)data->len;
+    apr_size_t slen = ((data->len+2)/3)*4 + 1; /* 0 terminated */
+    const unsigned char *udata = (const unsigned char*)data->data;
+    unsigned char *enc, *p = apr_pcalloc(pool, slen);
+    
+    enc = p;
+    for (i = 0; i < len-2; i+= 3) {
+        *p++ = BASE64URL_CHAR( (udata[i]   >> 2) );
+        *p++ = BASE64URL_CHAR( (udata[i]   << 4) + (udata[i+1] >> 4) );
+        *p++ = BASE64URL_CHAR( (udata[i+1] << 2) + (udata[i+2] >> 6) );
+        *p++ = BASE64URL_CHAR( (udata[i+2]) );
+    }
+    
+    if (i < len) {
+        *p++ = BASE64URL_CHAR( (udata[i] >> 2) );
+        if (i == (len - 1)) {
+            *p++ = BASE64URL_CHARS[ ((unsigned int)udata[i] << 4) & 0x3fu ];
+        }
+        else {
+            *p++ = BASE64URL_CHAR( (udata[i] << 4) + (udata[i+1] >> 4) );
+            *p++ = BASE64URL_CHAR( (udata[i+1] << 2) );
+        }
+    }
+    *p++ = '\0';
+    return (char *)enc;
+}
+
+/*******************************************************************************
+ * link header handling 
+ ******************************************************************************/
+
+typedef struct {
+    const char *s;
+    apr_size_t slen;
+    apr_size_t i;
+    apr_size_t link_start;
+    apr_size_t link_len;
+    apr_size_t pn_start;
+    apr_size_t pn_len;
+    apr_size_t pv_start;
+    apr_size_t pv_len;
+} link_ctx;
+
+static int attr_char(char c) 
+{
+    switch (c) {
+        case '!':
+        case '#':
+        case '$':
+        case '&':
+        case '+':
+        case '-':
+        case '.':
+        case '^':
+        case '_':
+        case '`':
+        case '|':
+        case '~':
+            return 1;
+        default:
+            return apr_isalnum(c);
+    }
+}
+
+static int ptoken_char(char c) 
+{
+    switch (c) {
+        case '!':
+        case '#':
+        case '$':
+        case '&':
+        case '\'':
+        case '(':
+        case ')':
+        case '*':
+        case '+':
+        case '-':
+        case '.':
+        case '/':
+        case ':':
+        case '<':
+        case '=':
+        case '>':
+        case '?':
+        case '@':
+        case '[':
+        case ']':
+        case '^':
+        case '_':
+        case '`':
+        case '{':
+        case '|':
+        case '}':
+        case '~':
+            return 1;
+        default:
+            return apr_isalnum(c);
+    }
+}
+
+static int skip_ws(link_ctx *ctx)
+{
+    char c;
+    while (ctx->i < ctx->slen 
+           && (((c = ctx->s[ctx->i]) == ' ') || (c == '\t'))) {
+        ++ctx->i;
+    }
+    return (ctx->i < ctx->slen);
+}
+
+static int skip_nonws(link_ctx *ctx)
+{
+    char c;
+    while (ctx->i < ctx->slen 
+           && (((c = ctx->s[ctx->i]) != ' ') && (c != '\t'))) {
+        ++ctx->i;
+    }
+    return (ctx->i < ctx->slen);
+}
+
+static unsigned int find_chr(link_ctx *ctx, char c, apr_size_t *pidx)
+{
+    apr_size_t j;
+    for (j = ctx->i; j < ctx->slen; ++j) {
+        if (ctx->s[j] == c) {
+            *pidx = j;
+            return 1;
+        }
+    } 
+    return 0;
+}
+
+static int read_chr(link_ctx *ctx, char c)
+{
+    if (ctx->i < ctx->slen && ctx->s[ctx->i] == c) {
+        ++ctx->i;
+        return 1;
+    }
+    return 0;
+}
+
+static int skip_qstring(link_ctx *ctx)
+{
+    if (skip_ws(ctx) && read_chr(ctx, '\"')) {
+        apr_size_t end;
+        if (find_chr(ctx, '\"', &end)) {
+            ctx->i = end + 1;
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static int skip_ptoken(link_ctx *ctx)
+{
+    if (skip_ws(ctx)) {
+        apr_size_t i;
+        for (i = ctx->i; i < ctx->slen && ptoken_char(ctx->s[i]); ++i) {
+            /* nop */
+        }
+        if (i > ctx->i) {
+            ctx->i = i;
+            return 1;
+        }
+    }
+    return 0;
+}
+
+
+static int read_link(link_ctx *ctx)
+{
+    ctx->link_start = ctx->link_len = 0;
+    if (skip_ws(ctx) && read_chr(ctx, '<')) {
+        apr_size_t end;
+        if (find_chr(ctx, '>', &end)) {
+            ctx->link_start = ctx->i;
+            ctx->link_len = end - ctx->link_start;
+            ctx->i = end + 1;
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static int skip_pname(link_ctx *ctx)
+{
+    if (skip_ws(ctx)) {
+        apr_size_t i;
+        for (i = ctx->i; i < ctx->slen && attr_char(ctx->s[i]); ++i) {
+            /* nop */
+        }
+        if (i > ctx->i) {
+            ctx->i = i;
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static int skip_pvalue(link_ctx *ctx)
+{
+    if (skip_ws(ctx) && read_chr(ctx, '=')) {
+        ctx->pv_start = ctx->i;
+        if (skip_qstring(ctx) || skip_ptoken(ctx)) {
+            ctx->pv_len = ctx->i - ctx->pv_start;
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static int skip_param(link_ctx *ctx)
+{
+    if (skip_ws(ctx) && read_chr(ctx, ';')) {
+        ctx->pn_start = ctx->i;
+        ctx->pn_len = 0;
+        if (skip_pname(ctx)) {
+            ctx->pn_len = ctx->i - ctx->pn_start;
+            ctx->pv_len = 0;
+            skip_pvalue(ctx); /* value is optional */
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static int pv_contains(link_ctx *ctx, const char *s)
+{
+    apr_size_t pvstart = ctx->pv_start;
+    apr_size_t pvlen = ctx->pv_len;
+    
+    if (ctx->s[pvstart] == '\"' && pvlen > 1) {
+        ++pvstart;
+        pvlen -= 2;
+    }
+    if (pvlen > 0) {
+        apr_size_t slen = strlen(s);
+        link_ctx pvctx;
+        apr_size_t i;
+        
+        memset(&pvctx, 0, sizeof(pvctx));
+        pvctx.s = ctx->s + pvstart;
+        pvctx.slen = pvlen;
+
+        for (i = 0; i < pvctx.slen; i = pvctx.i) {
+            skip_nonws(&pvctx);
+            if ((pvctx.i - i) == slen && !strncmp(s, pvctx.s + i, slen)) {
+                return 1;
+            }
+            skip_ws(&pvctx);
+        }
+    }
+    return 0;
+}
+
+/* RFC 5988 <https://tools.ietf.org/html/rfc5988#section-6.2.1>
+  Link           = "Link" ":" #link-value
+  link-value     = "<" URI-Reference ">" *( ";" link-param )
+  link-param     = ( ( "rel" "=" relation-types )
+                 | ( "anchor" "=" <"> URI-Reference <"> )
+                 | ( "rev" "=" relation-types )
+                 | ( "hreflang" "=" Language-Tag )
+                 | ( "media" "=" ( MediaDesc | ( <"> MediaDesc <"> ) ) )
+                 | ( "title" "=" quoted-string )
+                 | ( "title*" "=" ext-value )
+                 | ( "type" "=" ( media-type | quoted-mt ) )
+                 | ( link-extension ) )
+  link-extension = ( parmname [ "=" ( ptoken | quoted-string ) ] )
+                 | ( ext-name-star "=" ext-value )
+  ext-name-star  = parmname "*" ; reserved for RFC2231-profiled
+                                ; extensions.  Whitespace NOT
+                                ; allowed in between.
+  ptoken         = 1*ptokenchar
+  ptokenchar     = "!" | "#" | "$" | "%" | "&" | "'" | "("
+                 | ")" | "*" | "+" | "-" | "." | "/" | DIGIT
+                 | ":" | "<" | "=" | ">" | "?" | "@" | ALPHA
+                 | "[" | "]" | "^" | "_" | "`" | "{" | "|"
+                 | "}" | "~"
+  media-type     = type-name "/" subtype-name
+  quoted-mt      = <"> media-type <">
+  relation-types = relation-type
+                 | <"> relation-type *( 1*SP relation-type ) <">
+  relation-type  = reg-rel-type | ext-rel-type
+  reg-rel-type   = LOALPHA *( LOALPHA | DIGIT | "." | "-" )
+  ext-rel-type   = URI
+  
+  and from <https://tools.ietf.org/html/rfc5987>
+  parmname      = 1*attr-char
+  attr-char     = ALPHA / DIGIT
+                   / "!" / "#" / "$" / "&" / "+" / "-" / "."
+                   / "^" / "_" / "`" / "|" / "~"
+ */
+
+typedef struct {
+    apr_pool_t *pool;
+    const char *relation;
+    const char *url;
+} find_ctx;
+
+static int find_url(void *baton, const char *key, const char *value)
+{
+    find_ctx *outer = baton;
+    
+    if (!apr_strnatcasecmp("link", key)) {
+        link_ctx ctx;
+        
+        memset(&ctx, 0, sizeof(ctx));
+        ctx.s = value;
+        ctx.slen = strlen(value);
+        
+        while (read_link(&ctx)) {
+            while (skip_param(&ctx)) {
+                if (ctx.pn_len == 3 && !strncmp("rel", ctx.s + ctx.pn_start, 3)
+                    && pv_contains(&ctx, outer->relation)) {
+                    /* this is the link relation we are looking for */
+                    outer->url = apr_pstrndup(outer->pool, ctx.s + ctx.link_start, ctx.link_len);
+                    return 0;
+                }
+            }
+        }
+    }
+    return 1;
+}
+
+const char *md_link_find_relation(const apr_table_t *headers, 
+                                  apr_pool_t *pool, const char *relation)
+{
+    find_ctx ctx;
+    
+    memset(&ctx, 0, sizeof(ctx));
+    ctx.pool = pool;
+    ctx.relation = relation;
+    
+    apr_table_do(find_url, &ctx, headers, NULL);
+    
+    return ctx.url;
+}
+
+const char *md_util_parse_ct(apr_pool_t *pool, const char *cth)
+{
+    char       *type;
+    const char *p;
+    apr_size_t  hlen;
+
+    if (!cth) return NULL;
+
+    for( p = cth; *p && *p != ' ' && *p != ';'; ++p)
+        ;
+    hlen = (apr_size_t)(p - cth);
+    type = apr_pcalloc( pool, hlen + 1 );
+    assert(type);
+    memcpy(type, cth, hlen);
+    type[hlen] = '\0';
+
+    return type;
+    /* Could parse and return parameters here, but we don't need any at present.
+     */
+}
diff --git a/modules/md/md_util.h b/modules/md/md_util.h
new file mode 100644
index 0000000..e430655
--- /dev/null
+++ b/modules/md/md_util.h
@@ -0,0 +1,253 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_util_h
+#define mod_md_md_util_h
+
+#include <stdio.h>
+#include <apr_file_io.h>
+
+struct apr_array_header_t;
+struct apr_table_t;
+
+/**************************************************************************************************/
+/* pool utils */
+
+typedef apr_status_t md_util_action(void *baton, apr_pool_t *p, apr_pool_t *ptemp);
+typedef apr_status_t md_util_vaction(void *baton, apr_pool_t *p, apr_pool_t *ptemp, va_list ap);
+
+apr_status_t md_util_pool_do(md_util_action *cb, void *baton, apr_pool_t *p); 
+apr_status_t md_util_pool_vdo(md_util_vaction *cb, void *baton, apr_pool_t *p, ...); 
+
+/**************************************************************************************************/
+/* data chunks */
+
+typedef void md_data_free_fn(void *data);
+
+typedef struct md_data_t md_data_t;
+struct md_data_t {
+    const char *data;
+    apr_size_t len;
+    md_data_free_fn *free_data;
+};
+
+/**
+ * Init the data to empty, overwriting any content.
+ */
+void md_data_null(md_data_t *d);
+
+/**
+ * Create a new md_data_t, providing `len` bytes allocated from pool `p`.
+ */
+md_data_t *md_data_pmake(apr_size_t len, apr_pool_t *p);
+/**
+ * Initialize md_data_t 'd', providing `len` bytes allocated from pool `p`.
+ */
+void md_data_pinit(md_data_t *d, apr_size_t len, apr_pool_t *p);
+/**
+ * Initialize md_data_t 'd', by borrowing 'len' bytes in `data` without copying.
+ * `d` will not take ownership.
+ */
+void md_data_init(md_data_t *d, const char *data, apr_size_t len);
+
+/**
+ * Initialize md_data_t 'd', by borrowing the NUL-terminated `str`.
+ * `d` will not take ownership.
+ */
+void md_data_init_str(md_data_t *d, const char *str);
+
+/**
+ * Free any present data and clear (NULL) it. Passing NULL is permitted.
+ */
+void md_data_clear(md_data_t *d);
+
+md_data_t *md_data_make_pcopy(apr_pool_t *p, const char *data, apr_size_t len);
+
+apr_status_t md_data_assign_copy(md_data_t *dest, const char *src, apr_size_t src_len);
+void md_data_assign_pcopy(md_data_t *dest, const char *src, apr_size_t src_len, apr_pool_t *p);
+
+apr_status_t md_data_to_hex(const char **phex, char separator,
+                            apr_pool_t *p, const md_data_t *data);
+
+/**************************************************************************************************/
+/* generic arrays */
+
+/**
+ * In an array of pointers, remove all entries == elem. Returns the number
+ * of entries removed.
+ */
+int md_array_remove(struct apr_array_header_t *a, void *elem);
+
+/* 
+ * Remove the ith entry from the array.
+ * @return != 0 iff an entry was removed, e.g. idx was not outside range 
+ */
+int md_array_remove_at(struct apr_array_header_t *a, int idx);
+
+/**************************************************************************************************/
+/* string related */
+char *md_util_str_tolower(char *s);
+
+/**
+ * Return != 0 iff array is either NULL or empty 
+ */ 
+int md_array_is_empty(const struct apr_array_header_t *array);
+
+int md_array_str_index(const struct apr_array_header_t *array, const char *s, 
+                       int start, int case_sensitive);
+
+int md_array_str_eq(const struct apr_array_header_t *a1, 
+                    const struct apr_array_header_t *a2, int case_sensitive);
+
+struct apr_array_header_t *md_array_str_clone(apr_pool_t *p, struct apr_array_header_t *array);
+
+/**
+ * Create a new array with duplicates removed.
+ */
+struct apr_array_header_t *md_array_str_compact(apr_pool_t *p, struct apr_array_header_t *src,
+                                                int case_sensitive);
+
+/**
+ * Create a new array with all occurrences of <exclude> removed.
+ */
+struct apr_array_header_t *md_array_str_remove(apr_pool_t *p, struct apr_array_header_t *src, 
+                                               const char *exclude, int case_sensitive);
+
+int md_array_str_add_missing(struct apr_array_header_t *dest, 
+                             struct apr_array_header_t *src, int case_sensitive);
+
+/**************************************************************************************************/
+/* process execution */
+
+apr_status_t md_util_exec(apr_pool_t *p, const char *cmd, const char * const *argv,
+                          struct apr_array_header_t *env, int *exit_code);
+
+/**************************************************************************************************/
+/* dns name check */
+
+/**
+ * Is a host/domain name using allowed characters. Not a wildcard.
+ * @param domain     name to check
+ * @param need_fqdn  iff != 0, check that domain contains '.'
+ * @return != 0 iff domain looks like  a non-wildcard, legal DNS domain name.
+ */
+int md_dns_is_name(apr_pool_t *p, const char *domain, int need_fqdn);
+
+/**
+ * Check if the given domain is a valid wildcard DNS name, e.g. *.example.org
+ * @param domain    name to check
+ * @return != 0 iff domain is a DNS wildcard.
+ */
+int md_dns_is_wildcard(apr_pool_t *p, const char *domain);
+
+/**
+ * Determine iff pattern matches domain, including case-ignore and wildcard domains.
+ * It is assumed that both names follow dns syntax.
+ * @return != 0 iff pattern matches domain
+ */ 
+int md_dns_matches(const char *pattern, const char *domain);
+
+/**
+ * Create a new array with the minimal set out of the given domain names that match all
+ * of them. If none of the domains is a wildcard, only duplicates are removed.
+ * If domains contain a wildcard, any name matching the wildcard will be removed.
+ */
+struct apr_array_header_t *md_dns_make_minimal(apr_pool_t *p, 
+                                               struct apr_array_header_t *domains);
+
+/**
+ * Determine if the given domains cover the name, including wildcard matching.
+ * @return != 0 iff name is matched by list of domains
+ */
+int md_dns_domains_match(const apr_array_header_t *domains, const char *name);
+
+/**************************************************************************************************/
+/* file system related */
+
+struct apr_file_t;
+struct apr_finfo_t;
+
+apr_status_t md_util_fopen(FILE **pf, const char *fn, const char *mode);
+
+apr_status_t md_util_fcreatex(struct apr_file_t **pf, const char *fn, 
+                              apr_fileperms_t perms, apr_pool_t *p);
+
+apr_status_t md_util_path_merge(const char **ppath, apr_pool_t *p, ...);
+
+apr_status_t md_util_is_dir(const char *path, apr_pool_t *pool);
+apr_status_t md_util_is_file(const char *path, apr_pool_t *pool);
+apr_status_t md_util_is_unix_socket(const char *path, apr_pool_t *pool);
+int md_file_exists(const char *fname, apr_pool_t *p);
+
+typedef apr_status_t md_util_file_cb(void *baton, struct apr_file_t *f, apr_pool_t *p);
+
+apr_status_t md_util_freplace(const char *fpath, apr_fileperms_t perms, apr_pool_t *p, 
+                              md_util_file_cb *write, void *baton);
+
+/** 
+ * Remove a file/directory and all files/directories contain up to max_level. If max_level == 0,
+ * only an empty directory or a file can be removed.
+ */
+apr_status_t md_util_rm_recursive(const char *fpath, apr_pool_t *p, int max_level);
+
+typedef apr_status_t md_util_fdo_cb(void *baton, apr_pool_t *p, apr_pool_t *ptemp, 
+                                         const char *dir, const char *name, 
+                                         apr_filetype_e ftype);
+                                         
+apr_status_t md_util_files_do(md_util_fdo_cb *cb, void *baton, apr_pool_t *p, 
+                              const char *path, ...);
+
+/**
+ * Depth first traversal of directory tree starting at path.
+ */
+apr_status_t md_util_tree_do(md_util_fdo_cb *cb, void *baton, apr_pool_t *p, 
+                             const char *path, int follow_links);
+
+apr_status_t md_util_ftree_remove(const char *path, apr_pool_t *p);
+
+apr_status_t md_text_fread8k(const char **ptext, apr_pool_t *p, const char *fpath);
+apr_status_t md_text_fcreatex(const char *fpath, apr_fileperms_t 
+                              perms, apr_pool_t *p, const char *text);
+apr_status_t md_text_freplace(const char *fpath, apr_fileperms_t perms, 
+                              apr_pool_t *p, const char *text); 
+
+/**************************************************************************************************/
+/* base64 url encodings */
+const char *md_util_base64url_encode(const md_data_t *data, apr_pool_t *pool);
+apr_size_t md_util_base64url_decode(md_data_t *decoded, const char *encoded, 
+                                    apr_pool_t *pool);
+
+/**************************************************************************************************/
+/* http/url related */
+const char *md_util_schemify(apr_pool_t *p, const char *s, const char *def_scheme);
+
+apr_status_t md_util_abs_uri_check(apr_pool_t *p, const char *s, const char **perr);
+apr_status_t md_util_abs_http_uri_check(apr_pool_t *p, const char *uri, const char **perr);
+
+const char *md_link_find_relation(const struct apr_table_t *headers, 
+                                  apr_pool_t *pool, const char *relation);
+
+const char *md_util_parse_ct(apr_pool_t *pool, const char *cth);
+/**************************************************************************************************/
+/* retry logic */
+
+typedef apr_status_t md_util_try_fn(void *baton, int i);
+
+apr_status_t md_util_try(md_util_try_fn *fn, void *baton, int ignore_errs,  
+                         apr_interval_time_t timeout, apr_interval_time_t start_delay, 
+                         apr_interval_time_t max_delay, int backoff);
+
+#endif /* md_util_h */
diff --git a/modules/md/md_version.h b/modules/md/md_version.h
new file mode 100644
index 0000000..a8f3ef2
--- /dev/null
+++ b/modules/md/md_version.h
@@ -0,0 +1,43 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_version_h
+#define mod_md_md_version_h
+
+#undef PACKAGE_VERSION
+#undef PACKAGE_TARNAME
+#undef PACKAGE_STRING
+#undef PACKAGE_NAME
+#undef PACKAGE_BUGREPORT
+
+/**
+ * @macro
+ * Version number of the md module as c string
+ */
+#define MOD_MD_VERSION "2.4.21"
+
+/**
+ * @macro
+ * Numerical representation of the version number of the md module
+ * release. This is a 24 bit number with 8 bits for major number, 8 bits
+ * for minor and 8 bits for patch. Version 1.2.3 becomes 0x010203.
+ */
+#define MOD_MD_VERSION_NUM 0x020415
+
+#define MD_ACME_DEF_URL         "https://acme-v02.api.letsencrypt.org/directory"
+#define MD_TAILSCALE_DEF_URL    "file://localhost/var/run/tailscale/tailscaled.sock"
+
+#endif /* mod_md_md_version_h */
diff --git a/modules/md/mod_md.c b/modules/md/mod_md.c
new file mode 100644
index 0000000..32dea4f
--- /dev/null
+++ b/modules/md/mod_md.c
@@ -0,0 +1,1535 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <assert.h>
+#include <apr_optional.h>
+#include <apr_strings.h>
+
+#include <mpm_common.h>
+#include <httpd.h>
+#include <http_core.h>
+#include <http_protocol.h>
+#include <http_request.h>
+#include <http_ssl.h>
+#include <http_log.h>
+#include <http_vhost.h>
+#include <ap_listen.h>
+
+#include "mod_status.h"
+
+#include "md.h"
+#include "md_curl.h"
+#include "md_crypt.h"
+#include "md_event.h"
+#include "md_http.h"
+#include "md_json.h"
+#include "md_store.h"
+#include "md_store_fs.h"
+#include "md_log.h"
+#include "md_ocsp.h"
+#include "md_result.h"
+#include "md_reg.h"
+#include "md_status.h"
+#include "md_util.h"
+#include "md_version.h"
+#include "md_acme.h"
+#include "md_acme_authz.h"
+
+#include "mod_md.h"
+#include "mod_md_config.h"
+#include "mod_md_drive.h"
+#include "mod_md_ocsp.h"
+#include "mod_md_os.h"
+#include "mod_md_status.h"
+
+static void md_hooks(apr_pool_t *pool);
+
+AP_DECLARE_MODULE(md) = {
+    STANDARD20_MODULE_STUFF,
+    NULL,                 /* func to create per dir config */
+    NULL,                 /* func to merge per dir config */
+    md_config_create_svr, /* func to create per server config */
+    md_config_merge_svr,  /* func to merge per server config */
+    md_cmds,              /* command handlers */
+    md_hooks,
+#if defined(AP_MODULE_FLAG_NONE)
+    AP_MODULE_FLAG_ALWAYS_MERGE
+#endif
+};
+
+/**************************************************************************************************/
+/* logging setup */
+
+static server_rec *log_server;
+
+static int log_is_level(void *baton, apr_pool_t *p, md_log_level_t level)
+{
+    (void)baton;
+    (void)p;
+    if (log_server) {
+        return APLOG_IS_LEVEL(log_server, (int)level);
+    }
+    return level <= MD_LOG_INFO;
+}
+
+#define LOG_BUF_LEN 16*1024
+
+static void log_print(const char *file, int line, md_log_level_t level,
+                      apr_status_t rv, void *baton, apr_pool_t *p, const char *fmt, va_list ap)
+{
+    if (log_is_level(baton, p, level)) {
+        char buffer[LOG_BUF_LEN];
+
+        memset(buffer, 0, sizeof(buffer));
+        apr_vsnprintf(buffer, LOG_BUF_LEN-1, fmt, ap);
+        buffer[LOG_BUF_LEN-1] = '\0';
+
+        if (log_server) {
+            ap_log_error(file, line, APLOG_MODULE_INDEX, (int)level, rv, log_server, "%s", buffer);
+        }
+        else {
+            ap_log_perror(file, line, APLOG_MODULE_INDEX, (int)level, rv, p, "%s", buffer);
+        }
+    }
+}
+
+/**************************************************************************************************/
+/* mod_ssl interface */
+
+static void init_ssl(void)
+{
+    /* nop */
+}
+
+/**************************************************************************************************/
+/* lifecycle */
+
+static apr_status_t cleanup_setups(void *dummy)
+{
+    (void)dummy;
+    log_server = NULL;
+    return APR_SUCCESS;
+}
+
+static void init_setups(apr_pool_t *p, server_rec *base_server)
+{
+    log_server = base_server;
+    apr_pool_cleanup_register(p, NULL, cleanup_setups, apr_pool_cleanup_null);
+}
+
+/**************************************************************************************************/
+/* notification handling */
+
+typedef struct {
+    const char *reason;         /* what the notification is about */
+    apr_time_t min_interim;     /* minimum time between notifying for this reason */
+} notify_rate;
+
+static notify_rate notify_rates[] = {
+    { "renewing", apr_time_from_sec(MD_SECS_PER_HOUR) }, /* once per hour */
+    { "renewed", apr_time_from_sec(MD_SECS_PER_DAY) }, /* once per day */
+    { "installed", apr_time_from_sec(MD_SECS_PER_DAY) }, /* once per day */
+    { "expiring", apr_time_from_sec(MD_SECS_PER_DAY) },     /* once per day */
+    { "errored", apr_time_from_sec(MD_SECS_PER_HOUR) },     /* once per hour */
+    { "ocsp-renewed", apr_time_from_sec(MD_SECS_PER_DAY) }, /* once per day */
+    { "ocsp-errored", apr_time_from_sec(MD_SECS_PER_HOUR) }, /* once per hour */
+};
+
+static apr_status_t notify(md_job_t *job, const char *reason,
+                           md_result_t *result, apr_pool_t *p, void *baton)
+{
+    md_mod_conf_t *mc = baton;
+    const char * const *argv;
+    const char *cmdline;
+    int exit_code;
+    apr_status_t rv = APR_SUCCESS;
+    apr_time_t min_interim = 0;
+    md_timeperiod_t since_last;
+    const char *log_msg_reason;
+    int i;
+
+    log_msg_reason = apr_psprintf(p, "message-%s", reason);
+    for (i = 0; i < (int)(sizeof(notify_rates)/sizeof(notify_rates[0])); ++i) {
+        if (!strcmp(reason, notify_rates[i].reason)) {
+            min_interim = notify_rates[i].min_interim;
+        }
+    }
+    if (min_interim > 0) {
+        since_last.start = md_job_log_get_time_of_latest(job, log_msg_reason);
+        since_last.end = apr_time_now();
+        if (since_last.start > 0 && md_timeperiod_length(&since_last) < min_interim) {
+            /* not enough time has passed since we sent the last notification
+             * for this reason. */
+            md_log_perror(MD_LOG_MARK, MD_LOG_DEBUG, 0, p, APLOGNO(10267)
+                "%s: rate limiting notification about '%s'", job->mdomain, reason);
+            return APR_SUCCESS;
+        }
+    }
+
+    if (!strcmp("renewed", reason)) {
+        if (mc->notify_cmd) {
+            cmdline = apr_psprintf(p, "%s %s", mc->notify_cmd, job->mdomain);
+            apr_tokenize_to_argv(cmdline, (char***)&argv, p);
+            rv = md_util_exec(p, argv[0], argv, NULL, &exit_code);
+
+            if (APR_SUCCESS == rv && exit_code) rv = APR_EGENERAL;
+            if (APR_SUCCESS != rv) {
+                md_result_problem_printf(result, rv, MD_RESULT_LOG_ID(APLOGNO(10108)),
+                                         "MDNotifyCmd %s failed with exit code %d.",
+                                         mc->notify_cmd, exit_code);
+                md_result_log(result, MD_LOG_ERR);
+                md_job_log_append(job, "notify-error", result->problem, result->detail);
+                return rv;
+            }
+        }
+        md_log_perror(MD_LOG_MARK, MD_LOG_NOTICE, 0, p, APLOGNO(10059)
+                     "The Managed Domain %s has been setup and changes "
+                     "will be activated on next (graceful) server restart.", job->mdomain);
+    }
+    if (mc->message_cmd) {
+        cmdline = apr_psprintf(p, "%s %s %s", mc->message_cmd, reason, job->mdomain);
+        apr_tokenize_to_argv(cmdline, (char***)&argv, p);
+        rv = md_util_exec(p, argv[0], argv, NULL, &exit_code);
+
+        if (APR_SUCCESS == rv && exit_code) rv = APR_EGENERAL;
+        if (APR_SUCCESS != rv) {
+            md_result_problem_printf(result, rv, MD_RESULT_LOG_ID(APLOGNO(10109)),
+                                     "MDMessageCmd %s failed with exit code %d.",
+                                     mc->message_cmd, exit_code);
+            md_result_log(result, MD_LOG_ERR);
+            md_job_log_append(job, "message-error", reason, result->detail);
+            return rv;
+        }
+    }
+
+    md_job_log_append(job, log_msg_reason, NULL, NULL);
+    return APR_SUCCESS;
+}
+
+static apr_status_t on_event(const char *event, const char *mdomain, void *baton, 
+                             md_job_t *job, md_result_t *result, apr_pool_t *p)
+{
+    (void)mdomain;
+    return notify(job, event, result, p, baton);
+}
+
+/**************************************************************************************************/
+/* store setup */
+
+static apr_status_t store_file_ev(void *baton, struct md_store_t *store,
+                                    md_store_fs_ev_t ev, unsigned int group,
+                                    const char *fname, apr_filetype_e ftype,
+                                    apr_pool_t *p)
+{
+    server_rec *s = baton;
+    apr_status_t rv;
+
+    (void)store;
+    ap_log_error(APLOG_MARK, APLOG_TRACE3, 0, s, "store event=%d on %s %s (group %d)",
+                 ev, (ftype == APR_DIR)? "dir" : "file", fname, group);
+
+    /* Directories in group CHALLENGES, STAGING and OCSP are written to
+     * under a different user. Give her ownership.
+     */
+    if (ftype == APR_DIR) {
+        switch (group) {
+            case MD_SG_CHALLENGES:
+            case MD_SG_STAGING:
+            case MD_SG_OCSP:
+                rv = md_make_worker_accessible(fname, p);
+                if (APR_ENOTIMPL != rv) {
+                    return rv;
+                }
+                break;
+            default:
+                break;
+        }
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t check_group_dir(md_store_t *store, md_store_group_t group,
+                                    apr_pool_t *p, server_rec *s)
+{
+    const char *dir;
+    apr_status_t rv;
+
+    if (APR_SUCCESS == (rv = md_store_get_fname(&dir, store, group, NULL, NULL, p))
+        && APR_SUCCESS == (rv = apr_dir_make_recursive(dir, MD_FPROT_D_UALL_GREAD, p))) {
+        rv = store_file_ev(s, store, MD_S_FS_EV_CREATED, group, dir, APR_DIR, p);
+    }
+    return rv;
+}
+
+static apr_status_t setup_store(md_store_t **pstore, md_mod_conf_t *mc,
+                                apr_pool_t *p, server_rec *s)
+{
+    const char *base_dir;
+    apr_status_t rv;
+
+    base_dir = ap_server_root_relative(p, mc->base_dir);
+
+    if (APR_SUCCESS != (rv = md_store_fs_init(pstore, p, base_dir))) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10046)"setup store for %s", base_dir);
+        goto leave;
+    }
+
+    md_store_fs_set_event_cb(*pstore, store_file_ev, s);
+    if (APR_SUCCESS != (rv = check_group_dir(*pstore, MD_SG_CHALLENGES, p, s))
+        || APR_SUCCESS != (rv = check_group_dir(*pstore, MD_SG_STAGING, p, s))
+        || APR_SUCCESS != (rv = check_group_dir(*pstore, MD_SG_ACCOUNTS, p, s))
+        || APR_SUCCESS != (rv = check_group_dir(*pstore, MD_SG_OCSP, p, s))
+        ) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10047)
+                     "setup challenges directory");
+        goto leave;
+    }
+
+leave:
+    return rv;
+}
+
+/**************************************************************************************************/
+/* post config handling */
+
+static void merge_srv_config(md_t *md, md_srv_conf_t *base_sc, apr_pool_t *p)
+{
+    const char *contact;
+
+    if (!md->sc) {
+        md->sc = base_sc;
+    }
+
+    if (!md->ca_urls && md->sc->ca_urls) {
+        md->ca_urls = apr_array_copy(p, md->sc->ca_urls);
+    }
+    if (!md->ca_proto) {
+        md->ca_proto = md_config_gets(md->sc, MD_CONFIG_CA_PROTO);
+    }
+    if (!md->ca_agreement) {
+        md->ca_agreement = md_config_gets(md->sc, MD_CONFIG_CA_AGREEMENT);
+    }
+    contact = md_config_gets(md->sc, MD_CONFIG_CA_CONTACT);
+    if (md->contacts && md->contacts->nelts > 0) {
+        /* set explicitly */
+    }
+    else if (contact && contact[0]) {
+        apr_array_clear(md->contacts);
+        APR_ARRAY_PUSH(md->contacts, const char *) =
+        md_util_schemify(p, contact, "mailto");
+    }
+    else if( md->sc->s->server_admin && strcmp(DEFAULT_ADMIN, md->sc->s->server_admin)) {
+        apr_array_clear(md->contacts);
+        APR_ARRAY_PUSH(md->contacts, const char *) =
+        md_util_schemify(p, md->sc->s->server_admin, "mailto");
+    }
+    if (md->renew_mode == MD_RENEW_DEFAULT) {
+        md->renew_mode = md_config_geti(md->sc, MD_CONFIG_DRIVE_MODE);
+    }
+    if (!md->renew_window) md_config_get_timespan(&md->renew_window, md->sc, MD_CONFIG_RENEW_WINDOW);
+    if (!md->warn_window) md_config_get_timespan(&md->warn_window, md->sc, MD_CONFIG_WARN_WINDOW);
+    if (md->transitive < 0) {
+        md->transitive = md_config_geti(md->sc, MD_CONFIG_TRANSITIVE);
+    }
+    if (!md->ca_challenges && md->sc->ca_challenges) {
+        md->ca_challenges = apr_array_copy(p, md->sc->ca_challenges);
+    }
+    if (md_pkeys_spec_is_empty(md->pks)) {
+        md->pks = md->sc->pks;
+    }
+    if (md->require_https < 0) {
+        md->require_https = md_config_geti(md->sc, MD_CONFIG_REQUIRE_HTTPS);
+    }
+    if (!md->ca_eab_kid) {
+        md->ca_eab_kid = md->sc->ca_eab_kid;
+        md->ca_eab_hmac = md->sc->ca_eab_hmac;
+    }
+    if (md->must_staple < 0) {
+        md->must_staple = md_config_geti(md->sc, MD_CONFIG_MUST_STAPLE);
+    }
+    if (md->stapling < 0) {
+        md->stapling = md_config_geti(md->sc, MD_CONFIG_STAPLING);
+    }
+}
+
+static apr_status_t check_coverage(md_t *md, const char *domain, server_rec *s,
+                                   int *pupdates, apr_pool_t *p)
+{
+    if (md_contains(md, domain, 0)) {
+        return APR_SUCCESS;
+    }
+    else if (md->transitive) {
+        APR_ARRAY_PUSH(md->domains, const char*) = apr_pstrdup(p, domain);
+        *pupdates |= MD_UPD_DOMAINS;
+        return APR_SUCCESS;
+    }
+    else {
+        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(10040)
+                     "Virtual Host %s:%d matches Managed Domain '%s', but the "
+                     "name/alias %s itself is not managed. A requested MD certificate "
+                     "will not match ServerName.",
+                     s->server_hostname, s->port, md->name, domain);
+        return APR_EINVAL;
+    }
+}
+
+static apr_status_t md_cover_server(md_t *md, server_rec *s, int *pupdates, apr_pool_t *p)
+{
+    apr_status_t rv;
+    const char *name;
+    int i;
+
+    if (APR_SUCCESS == (rv = check_coverage(md, s->server_hostname, s, pupdates, p))) {
+        ap_log_error(APLOG_MARK, APLOG_TRACE1, 0, s,
+                     "md[%s]: auto add, covers name %s", md->name, s->server_hostname);
+        for (i = 0; s->names && i < s->names->nelts; ++i) {
+            name = APR_ARRAY_IDX(s->names, i, const char*);
+            if (APR_SUCCESS != (rv = check_coverage(md, name, s, pupdates, p))) {
+                break;
+            }
+            ap_log_error(APLOG_MARK, APLOG_TRACE1, 0, s,
+                         "md[%s]: auto add, covers alias %s", md->name, name);
+        }
+    }
+    return rv;
+}
+
+static int uses_port(server_rec *s, int port)
+{
+    server_addr_rec *sa;
+    int match = 0;
+    for (sa = s->addrs; sa; sa = sa->next) {
+        if (sa->host_port == port) {
+            /* host_addr might be general (0.0.0.0) or specific, we count this as match */
+            match = 1;
+        }
+        else {
+            /* uses other port/wildcard */
+            return 0;
+        }
+    }
+    return match;
+}
+
+static apr_status_t detect_supported_protocols(md_mod_conf_t *mc, server_rec *s,
+                                               apr_pool_t *p, int log_level)
+{
+    ap_listen_rec *lr;
+    apr_sockaddr_t *sa;
+    int can_http, can_https;
+
+    if (mc->can_http >= 0 && mc->can_https >= 0) goto set_and_leave;
+
+    can_http = can_https = 0;
+    for (lr = ap_listeners; lr; lr = lr->next) {
+        for (sa = lr->bind_addr; sa; sa = sa->next) {
+            if  (sa->port == mc->local_80
+                 && (!lr->protocol || !strncmp("http", lr->protocol, 4))) {
+                can_http = 1;
+            }
+            else if (sa->port == mc->local_443
+                     && (!lr->protocol || !strncmp("http", lr->protocol, 4))) {
+                can_https = 1;
+            }
+        }
+    }
+    if (mc->can_http < 0) mc->can_http = can_http;
+    if (mc->can_https < 0) mc->can_https = can_https;
+    ap_log_error(APLOG_MARK, log_level, 0, s, APLOGNO(10037)
+                 "server seems%s reachable via http: and%s reachable via https:",
+                 mc->can_http? "" : " not", mc->can_https? "" : " not");
+set_and_leave:
+    return md_reg_set_props(mc->reg, p, mc->can_http, mc->can_https);
+}
+
+static server_rec *get_public_https_server(md_t *md, const char *domain, server_rec *base_server)
+{
+    md_srv_conf_t *sc;
+    md_mod_conf_t *mc;
+    server_rec *s;
+    server_rec *res = NULL;
+    request_rec r;
+    int i;
+    int check_port = 1;
+
+    sc = md_config_get(base_server);
+    mc = sc->mc;
+    memset(&r, 0, sizeof(r));
+
+    if (md->ca_challenges && md->ca_challenges->nelts > 0) {
+        /* skip the port check if "tls-alpn-01" is pre-configured */
+        check_port = !(md_array_str_index(md->ca_challenges, MD_AUTHZ_TYPE_TLSALPN01, 0, 0) >= 0);
+    }
+
+    if (check_port && !mc->can_https) return NULL;
+
+    /* find an ssl server matching domain from MD */
+    for (s = base_server; s; s = s->next) {
+        sc = md_config_get(s);
+        if (!sc || !sc->is_ssl || !sc->assigned) continue;
+        if (base_server == s && !mc->manage_base_server) continue;
+        if (base_server != s && check_port && mc->local_443 > 0 && !uses_port(s, mc->local_443)) continue;
+        for (i = 0; i < sc->assigned->nelts; ++i) {
+            if (md == APR_ARRAY_IDX(sc->assigned, i, md_t*)) {
+                r.server = s;
+                if (ap_matches_request_vhost(&r, domain, s->port)) {
+                    if (check_port) {
+                        return s;
+                    }
+                    else {
+                        /* there may be multiple matching servers because we ignore the port.
+                           if possible, choose a server that supports the acme-tls/1 protocol */
+                        if (ap_is_allowed_protocol(NULL, NULL, s, PROTO_ACME_TLS_1)) {
+                            return s;
+                        }
+                        res = s;
+                    }
+                }
+            }
+        }
+    }
+    return res;
+}
+
+static apr_status_t auto_add_domains(md_t *md, server_rec *base_server, apr_pool_t *p)
+{
+    md_srv_conf_t *sc;
+    server_rec *s;
+    apr_status_t rv = APR_SUCCESS;
+    int updates;
+
+    /* Ad all domain names used in SSL VirtualHosts, if not already there */
+    ap_log_error(APLOG_MARK, APLOG_TRACE1, 0, base_server,
+                 "md[%s]: auto add domains", md->name);
+    updates = 0;
+    for (s = base_server; s; s = s->next) {
+        sc = md_config_get(s);
+        if (!sc || !sc->is_ssl || !sc->assigned || sc->assigned->nelts != 1) continue;
+        if (md != APR_ARRAY_IDX(sc->assigned, 0, md_t*)) continue;
+        if (APR_SUCCESS != (rv = md_cover_server(md, s, &updates, p))) {
+            return rv;
+        }
+    }
+    return rv;
+}
+
+static void init_acme_tls_1_domains(md_t *md, server_rec *base_server)
+{
+    md_srv_conf_t *sc;
+    md_mod_conf_t *mc;
+    server_rec *s;
+    int i;
+    const char *domain;
+
+    /* Collect those domains that support the "acme-tls/1" protocol. This
+     * is part of the MD (and not tested dynamically), since challenge selection
+     * may be done outside the server, e.g. in the a2md command. */
+    sc = md_config_get(base_server);
+    mc = sc->mc;
+    apr_array_clear(md->acme_tls_1_domains);
+    for (i = 0; i < md->domains->nelts; ++i) {
+        domain = APR_ARRAY_IDX(md->domains, i, const char*);
+        s = get_public_https_server(md, domain, base_server);
+        /* If we did not find a specific virtualhost for md and manage
+         * the base_server, that one is inspected */
+        if (NULL == s && mc->manage_base_server) s = base_server;
+        if (NULL == s) {
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, base_server, APLOGNO(10168)
+                         "%s: no https server_rec found for %s", md->name, domain);
+            continue;
+        }
+        if (!ap_is_allowed_protocol(NULL, NULL, s, PROTO_ACME_TLS_1)) {
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, base_server, APLOGNO(10169)
+                         "%s: https server_rec for %s does not have protocol %s enabled",
+                         md->name, domain, PROTO_ACME_TLS_1);
+            continue;
+        }
+        APR_ARRAY_PUSH(md->acme_tls_1_domains, const char*) = domain;
+    }
+}
+
+static apr_status_t link_md_to_servers(md_mod_conf_t *mc, md_t *md, server_rec *base_server,
+                                       apr_pool_t *p)
+{
+    server_rec *s;
+    request_rec r;
+    md_srv_conf_t *sc;
+    int i;
+    const char *domain, *uri;
+
+    sc = md_config_get(base_server);
+
+    /* Assign the MD to all server_rec configs that it matches. If there already
+     * is an assigned MD not equal this one, the configuration is in error.
+     */
+    memset(&r, 0, sizeof(r));
+    for (s = base_server; s; s = s->next) {
+        if (!mc->manage_base_server && s == base_server) {
+            /* we shall not assign ourselves to the base server */
+            continue;
+        }
+
+        r.server = s;
+        for (i = 0; i < md->domains->nelts; ++i) {
+            domain = APR_ARRAY_IDX(md->domains, i, const char*);
+
+            if (ap_matches_request_vhost(&r, domain, s->port)
+                || (md_dns_is_wildcard(p, domain) && md_dns_matches(domain, s->server_hostname))) {
+                /* Create a unique md_srv_conf_t record for this server, if there is none yet */
+                sc = md_config_get_unique(s, p);
+                if (!sc->assigned) sc->assigned = apr_array_make(p, 2, sizeof(md_t*));
+
+                APR_ARRAY_PUSH(sc->assigned, md_t*) = md;
+                ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, base_server, APLOGNO(10041)
+                             "Server %s:%d matches md %s (config %s) for domain %s, "
+                             "has now %d MDs",
+                             s->server_hostname, s->port, md->name, sc->name,
+                             domain, (int)sc->assigned->nelts);
+
+                if (md->contacts && md->contacts->nelts > 0) {
+                    /* set explicitly */
+                }
+                else if (sc->ca_contact && sc->ca_contact[0]) {
+                    uri = md_util_schemify(p, sc->ca_contact, "mailto");
+                    if (md_array_str_index(md->contacts, uri, 0, 0) < 0) {
+                        APR_ARRAY_PUSH(md->contacts, const char *) = uri;
+                        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, base_server, APLOGNO(10044)
+                                     "%s: added contact %s", md->name, uri);
+                    }
+                }
+                else if (s->server_admin && strcmp(DEFAULT_ADMIN, s->server_admin)) {
+                    uri = md_util_schemify(p, s->server_admin, "mailto");
+                    if (md_array_str_index(md->contacts, uri, 0, 0) < 0) {
+                        APR_ARRAY_PUSH(md->contacts, const char *) = uri;
+                        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, base_server, APLOGNO(10237)
+                                     "%s: added contact %s", md->name, uri);
+                    }
+                }
+                break;
+            }
+        }
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t link_mds_to_servers(md_mod_conf_t *mc, server_rec *s, apr_pool_t *p)
+{
+    int i;
+    md_t *md;
+    apr_status_t rv = APR_SUCCESS;
+
+    apr_array_clear(mc->unused_names);
+    for (i = 0; i < mc->mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(mc->mds, i, md_t*);
+        if (APR_SUCCESS != (rv = link_md_to_servers(mc, md, s, p))) {
+            goto leave;
+        }
+    }
+leave:
+    return rv;
+}
+
+static apr_status_t merge_mds_with_conf(md_mod_conf_t *mc, apr_pool_t *p,
+                                        server_rec *base_server, int log_level)
+{
+    md_srv_conf_t *base_conf;
+    md_t *md, *omd;
+    const char *domain;
+    md_timeslice_t *ts;
+    apr_status_t rv = APR_SUCCESS;
+    int i, j;
+
+    /* The global module configuration 'mc' keeps a list of all configured MDomains
+     * in the server. This list is collected during configuration processing and,
+     * in the post config phase, get updated from all merged server configurations
+     * before the server starts processing.
+     */
+    base_conf = md_config_get(base_server);
+    md_config_get_timespan(&ts, base_conf, MD_CONFIG_RENEW_WINDOW);
+    if (ts) md_reg_set_renew_window_default(mc->reg, ts);
+    md_config_get_timespan(&ts, base_conf, MD_CONFIG_WARN_WINDOW);
+    if (ts) md_reg_set_warn_window_default(mc->reg, ts);
+
+    /* Complete the properties of the MDs, now that we have the complete, merged
+     * server configurations.
+     */
+    for (i = 0; i < mc->mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(mc->mds, i, md_t*);
+        merge_srv_config(md, base_conf, p);
+
+        /* Check that we have no overlap with the MDs already completed */
+        for (j = 0; j < i; ++j) {
+            omd = APR_ARRAY_IDX(mc->mds, j, md_t*);
+            if ((domain = md_common_name(md, omd)) != NULL) {
+                ap_log_error(APLOG_MARK, APLOG_ERR, 0, base_server, APLOGNO(10038)
+                             "two Managed Domains have an overlap in domain '%s'"
+                             ", first definition in %s(line %d), second in %s(line %d)",
+                             domain, md->defn_name, md->defn_line_number,
+                             omd->defn_name, omd->defn_line_number);
+                return APR_EINVAL;
+            }
+        }
+
+        if (md->cert_files && md->cert_files->nelts) {
+            if (!md->pkey_files || (md->cert_files->nelts != md->pkey_files->nelts)) {
+                ap_log_error(APLOG_MARK, APLOG_ERR, 0, base_server, APLOGNO(10170)
+                             "The Managed Domain '%s' "
+                             "needs one MDCertificateKeyFile for each MDCertificateFile.",
+                             md->name);
+                return APR_EINVAL;
+            }
+        }
+        else if (md->pkey_files && md->pkey_files->nelts 
+            && (!md->cert_files || !md->cert_files->nelts)) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, 0, base_server, APLOGNO(10171)
+                         "The Managed Domain '%s' "
+                         "has MDCertificateKeyFile(s) but no MDCertificateFile.",
+                         md->name);
+            return APR_EINVAL;
+        }
+
+        if (APLOG_IS_LEVEL(base_server, log_level)) {
+            ap_log_error(APLOG_MARK, log_level, 0, base_server, APLOGNO(10039)
+                         "Completed MD[%s, CA=%s, Proto=%s, Agreement=%s, renew-mode=%d "
+                         "renew_window=%s, warn_window=%s",
+                         md->name, md->ca_effective, md->ca_proto, md->ca_agreement, md->renew_mode,
+                         md->renew_window? md_timeslice_format(md->renew_window, p) : "unset",
+                         md->warn_window? md_timeslice_format(md->warn_window, p) : "unset");
+        }
+    }
+    return rv;
+}
+
+static apr_status_t check_invalid_duplicates(server_rec *base_server)
+{
+    server_rec *s;
+    md_srv_conf_t *sc;
+
+    ap_log_error( APLOG_MARK, APLOG_TRACE1, 0, base_server,
+                 "checking duplicate ssl assignments");
+    for (s = base_server; s; s = s->next) {
+        sc = md_config_get(s);
+        if (!sc || !sc->assigned) continue;
+
+        if (sc->assigned->nelts > 1 && sc->is_ssl) {
+            /* duplicate assignment to SSL VirtualHost, not allowed */
+            ap_log_error(APLOG_MARK, APLOG_ERR, 0, base_server, APLOGNO(10042)
+                         "conflict: %d MDs match to SSL VirtualHost %s, there can at most be one.",
+                         (int)sc->assigned->nelts, s->server_hostname);
+            return APR_EINVAL;
+        }
+    }
+    return APR_SUCCESS;
+}
+
+static apr_status_t check_usage(md_mod_conf_t *mc, md_t *md, server_rec *base_server,
+                                apr_pool_t *p, apr_pool_t *ptemp)
+{
+    server_rec *s;
+    md_srv_conf_t *sc;
+    apr_status_t rv = APR_SUCCESS;
+    int i, has_ssl;
+    apr_array_header_t *servers;
+
+    (void)p;
+    servers = apr_array_make(ptemp, 5, sizeof(server_rec*));
+    has_ssl = 0;
+    for (s = base_server; s; s = s->next) {
+        sc = md_config_get(s);
+        if (!sc || !sc->assigned) continue;
+        for (i = 0; i < sc->assigned->nelts; ++i) {
+            if (md == APR_ARRAY_IDX(sc->assigned, i, md_t*)) {
+                APR_ARRAY_PUSH(servers, server_rec*) = s;
+                if (sc->is_ssl) has_ssl = 1;
+            }
+        }
+    }
+
+    if (!has_ssl && md->require_https > MD_REQUIRE_OFF) {
+        /* We require https for this MD, but do we have a SSL vhost? */
+        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, base_server, APLOGNO(10105)
+                     "MD %s does not match any VirtualHost with 'SSLEngine on', "
+                     "but is configured to require https. This cannot work.", md->name);
+    }
+    if (apr_is_empty_array(servers)) {
+        if (md->renew_mode != MD_RENEW_ALWAYS) {
+            /* Not an error, but looks suspicious */
+            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, base_server, APLOGNO(10045)
+                         "No VirtualHost matches Managed Domain %s", md->name);
+            APR_ARRAY_PUSH(mc->unused_names, const char*)  = md->name;
+        }
+    }
+    return rv;
+}
+
+static int init_cert_watch_status(md_mod_conf_t *mc, apr_pool_t *p, apr_pool_t *ptemp, server_rec *s)
+{
+    md_t *md;
+    md_result_t *result;
+    int i, count;
+
+    /* Calculate the list of MD names which we need to watch:
+     * - all MDs that are used somewhere
+     * - all MDs in drive mode 'AUTO' that are not in 'unused_names'
+     */
+    count = 0;
+    result = md_result_make(ptemp, APR_SUCCESS);
+    for (i = 0; i < mc->mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(mc->mds, i, md_t*);
+        md_result_set(result, APR_SUCCESS, NULL);
+        md->watched = 0;
+        if (md->state == MD_S_ERROR) {
+            md_result_set(result, APR_EGENERAL,
+                          "in error state, unable to drive forward. This "
+                          "indicates an incomplete or inconsistent configuration. "
+                          "Please check the log for warnings in this regard.");
+            continue;
+        }
+
+        if (md->renew_mode == MD_RENEW_AUTO
+            && md_array_str_index(mc->unused_names, md->name, 0, 0) >= 0) {
+            /* This MD is not used in any virtualhost, do not watch */
+            continue;
+        }
+
+        if (md_will_renew_cert(md)) {
+            /* make a test init to detect early errors. */
+            md_reg_test_init(mc->reg, md, mc->env, result, p);
+            if (APR_SUCCESS != result->status && result->detail) {
+                apr_hash_set(mc->init_errors, md->name, APR_HASH_KEY_STRING, apr_pstrdup(p, result->detail));
+                ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(10173)
+                             "md[%s]: %s", md->name, result->detail);
+            }
+        }
+
+        md->watched = 1;
+        ++count;
+    }
+    return count;
+}
+
+static apr_status_t md_post_config_before_ssl(apr_pool_t *p, apr_pool_t *plog,
+                                              apr_pool_t *ptemp, server_rec *s)
+{
+    void *data = NULL;
+    const char *mod_md_init_key = "mod_md_init_counter";
+    md_srv_conf_t *sc;
+    md_mod_conf_t *mc;
+    apr_status_t rv = APR_SUCCESS;
+    int dry_run = 0, log_level = APLOG_DEBUG;
+    md_store_t *store;
+
+    apr_pool_userdata_get(&data, mod_md_init_key, s->process->pool);
+    if (data == NULL) {
+        /* At the first start, httpd makes a config check dry run. It
+         * runs all config hooks to check if it can. If so, it does
+         * this all again and starts serving requests.
+         *
+         * On a dry run, we therefore do all the cheap config things we
+         * need to do to find out if the settings are ok. More expensive
+         * things we delay to the real run.
+         */
+        dry_run = 1;
+        log_level = APLOG_TRACE1;
+        ap_log_error( APLOG_MARK, log_level, 0, s, APLOGNO(10070)
+                     "initializing post config dry run");
+        apr_pool_userdata_set((const void *)1, mod_md_init_key,
+                              apr_pool_cleanup_null, s->process->pool);
+    }
+    else {
+        ap_log_error( APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(10071)
+                     "mod_md (v%s), initializing...", MOD_MD_VERSION);
+    }
+
+    (void)plog;
+    init_setups(p, s);
+    md_log_set(log_is_level, log_print, NULL);
+
+    md_config_post_config(s, p);
+    sc = md_config_get(s);
+    mc = sc->mc;
+    mc->dry_run = dry_run;
+
+    md_event_init(p);
+    md_event_subscribe(on_event, mc);
+
+    rv = setup_store(&store, mc, p, s);
+    if (APR_SUCCESS != rv) goto leave;
+
+    rv = md_reg_create(&mc->reg, p, store, mc->proxy_url, mc->ca_certs,
+                       mc->min_delay, mc->retry_failover,
+                       mc->use_store_locks, mc->lock_wait_timeout);
+    if (APR_SUCCESS != rv) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10072) "setup md registry");
+        goto leave;
+    }
+
+    /* renew on 30% remaining /*/
+    rv = md_ocsp_reg_make(&mc->ocsp, p, store, mc->ocsp_renew_window,
+                          AP_SERVER_BASEVERSION, mc->proxy_url,
+                          mc->min_delay);
+    if (APR_SUCCESS != rv) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10196) "setup ocsp registry");
+        goto leave;
+    }
+
+    init_ssl();
+
+    /* How to bootstrap this module:
+     * 1. find out if we know if http: and/or https: requests will arrive
+     * 2. apply the now complete configuration settings to the MDs
+     * 3. Link MDs to the server_recs they are used in. Detect unused MDs.
+     * 4. Update the store with the MDs. Change domain names, create new MDs, etc.
+     *    Basically all MD properties that are configured directly.
+     *    WARNING: this may change the name of an MD. If an MD loses the first
+     *    of its domain names, it first gets the new first one as name. The
+     *    store will find the old settings and "recover" the previous name.
+     * 5. Load any staged data from previous driving.
+     * 6. on a dry run, this is all we do
+     * 7. Read back the MD properties that reflect the existence and aspect of
+     *    credentials that are in the store (or missing there).
+     *    Expiry times, MD state, etc.
+     * 8. Determine the list of MDs that need driving/supervision.
+     * 9. Cleanup any left-overs in registry/store that are no longer needed for
+     *    the list of MDs as we know it now.
+     * 10. If this list is non-empty, setup a watchdog to run.
+     */
+    /*1*/
+    if (APR_SUCCESS != (rv = detect_supported_protocols(mc, s, p, log_level))) goto leave;
+    /*2*/
+    if (APR_SUCCESS != (rv = merge_mds_with_conf(mc, p, s, log_level))) goto leave;
+    /*3*/
+    if (APR_SUCCESS != (rv = link_mds_to_servers(mc, s, p))) goto leave;
+    /*4*/
+    if (APR_SUCCESS != (rv = md_reg_lock_global(mc->reg, ptemp))) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10398)
+                     "unable to obtain global registry lock, "
+                     "renewed certificates may remain inactive on "
+                     "this httpd instance!");
+        /* FIXME: or should we fail the server start/reload here? */
+        rv = APR_SUCCESS;
+        goto leave;
+    }
+    if (APR_SUCCESS != (rv = md_reg_sync_start(mc->reg, mc->mds, ptemp))) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10073)
+                     "syncing %d mds to registry", mc->mds->nelts);
+        goto leave;
+    }
+    /*5*/
+    md_reg_load_stagings(mc->reg, mc->mds, mc->env, p);
+leave:
+    md_reg_unlock_global(mc->reg, ptemp);
+    return rv;
+}
+
+static apr_status_t md_post_config_after_ssl(apr_pool_t *p, apr_pool_t *plog,
+                                             apr_pool_t *ptemp, server_rec *s)
+{
+    md_srv_conf_t *sc;
+    apr_status_t rv = APR_SUCCESS;
+    md_mod_conf_t *mc;
+    int watched, i;
+    md_t *md;
+
+    (void)ptemp;
+    (void)plog;
+    sc = md_config_get(s);
+
+    /*6*/
+    if (!sc || !sc->mc || sc->mc->dry_run) goto leave;
+    mc = sc->mc;
+
+    /*7*/
+    if (APR_SUCCESS != (rv = check_invalid_duplicates(s))) {
+        goto leave;
+    }
+    apr_array_clear(mc->unused_names);
+    for (i = 0; i < mc->mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(mc->mds, i, md_t *);
+
+        ap_log_error( APLOG_MARK, APLOG_TRACE2, rv, s, "md{%s}: auto_add", md->name);
+        if (APR_SUCCESS != (rv = auto_add_domains(md, s, p))) {
+            goto leave;
+        }
+        init_acme_tls_1_domains(md, s);
+        ap_log_error( APLOG_MARK, APLOG_TRACE2, rv, s, "md{%s}: check_usage", md->name);
+        if (APR_SUCCESS != (rv = check_usage(mc, md, s, p, ptemp))) {
+            goto leave;
+        }
+        ap_log_error( APLOG_MARK, APLOG_TRACE2, rv, s, "md{%s}: sync_finish", md->name);
+        if (APR_SUCCESS != (rv = md_reg_sync_finish(mc->reg, md, p, ptemp))) {
+            ap_log_error( APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10172)
+                         "md[%s]: error syncing to store", md->name);
+            goto leave;
+        }
+    }
+    /*8*/
+    ap_log_error( APLOG_MARK, APLOG_TRACE2, rv, s, "init_cert_watch");
+    watched = init_cert_watch_status(mc, p, ptemp, s);
+    /*9*/
+    ap_log_error( APLOG_MARK, APLOG_TRACE2, rv, s, "cleanup challenges");
+    md_reg_cleanup_challenges(mc->reg, p, ptemp, mc->mds);
+
+    /* From here on, the domains in the registry are readonly
+     * and only staging/challenges may be manipulated */
+    md_reg_freeze_domains(mc->reg, mc->mds);
+
+    if (watched) {
+        /*10*/
+        ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(10074)
+                     "%d out of %d mds need watching", watched, mc->mds->nelts);
+
+        md_http_use_implementation(md_curl_get_impl(p));
+        rv = md_renew_start_watching(mc, s, p);
+    }
+    else {
+        ap_log_error( APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(10075) "no mds to supervise");
+    }
+
+    if (!mc->ocsp || md_ocsp_count(mc->ocsp) == 0) {
+        ap_log_error( APLOG_MARK, APLOG_TRACE1, 0, s, "no ocsp to manage");
+        goto leave;
+    }
+
+    md_http_use_implementation(md_curl_get_impl(p));
+    rv = md_ocsp_start_watching(mc, s, p);
+
+leave:
+    ap_log_error( APLOG_MARK, APLOG_TRACE2, rv, s, "post_config done");
+    return rv;
+}
+
+/**************************************************************************************************/
+/* connection context */
+
+typedef struct {
+    const char *protocol;
+} md_conn_ctx;
+
+static const char *md_protocol_get(const conn_rec *c)
+{
+    md_conn_ctx *ctx;
+
+    ctx = (md_conn_ctx*)ap_get_module_config(c->conn_config, &md_module);
+    return ctx? ctx->protocol : NULL;
+}
+
+/**************************************************************************************************/
+/* ALPN handling */
+
+static int md_protocol_propose(conn_rec *c, request_rec *r,
+                               server_rec *s,
+                               const apr_array_header_t *offers,
+                               apr_array_header_t *proposals)
+{
+    (void)s;
+    if (!r && offers && ap_ssl_conn_is_ssl(c)
+        && ap_array_str_contains(offers, PROTO_ACME_TLS_1)) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c,
+                      "proposing protocol '%s'", PROTO_ACME_TLS_1);
+        APR_ARRAY_PUSH(proposals, const char*) = PROTO_ACME_TLS_1;
+        return OK;
+    }
+    return DECLINED;
+}
+
+static int md_protocol_switch(conn_rec *c, request_rec *r, server_rec *s,
+                              const char *protocol)
+{
+    md_conn_ctx *ctx;
+
+    (void)s;
+    if (!r && ap_ssl_conn_is_ssl(c) && !strcmp(PROTO_ACME_TLS_1, protocol)) {
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c,
+                      "switching protocol '%s'", PROTO_ACME_TLS_1);
+        ctx = apr_pcalloc(c->pool, sizeof(*ctx));
+        ctx->protocol = PROTO_ACME_TLS_1;
+        ap_set_module_config(c->conn_config, &md_module, ctx);
+
+        c->keepalive = AP_CONN_CLOSE;
+        return OK;
+    }
+    return DECLINED;
+}
+
+
+/**************************************************************************************************/
+/* Access API to other httpd components */
+
+static void fallback_fnames(apr_pool_t *p, md_pkey_spec_t *kspec, char **keyfn, char **certfn )
+{
+    *keyfn  = apr_pstrcat(p, "fallback-", md_pkey_filename(kspec, p), NULL);
+    *certfn = apr_pstrcat(p, "fallback-", md_chain_filename(kspec, p), NULL);
+}
+
+static apr_status_t make_fallback_cert(md_store_t *store, const md_t *md, md_pkey_spec_t *kspec,
+                                       server_rec *s, apr_pool_t *p, char *keyfn, char *crtfn)
+{
+    md_pkey_t *pkey;
+    md_cert_t *cert;
+    apr_status_t rv;
+
+    if (APR_SUCCESS != (rv = md_pkey_gen(&pkey, p, kspec))
+        || APR_SUCCESS != (rv = md_store_save(store, p, MD_SG_DOMAINS, md->name,
+                                keyfn, MD_SV_PKEY, (void*)pkey, 0))
+        || APR_SUCCESS != (rv = md_cert_self_sign(&cert, "Apache Managed Domain Fallback",
+                                    md->domains, pkey, apr_time_from_sec(14 * MD_SECS_PER_DAY), p))
+        || APR_SUCCESS != (rv = md_store_save(store, p, MD_SG_DOMAINS, md->name,
+                                crtfn, MD_SV_CERT, (void*)cert, 0))) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10174)
+                     "%s: make fallback %s certificate", md->name, md_pkey_spec_name(kspec));
+    }
+    return rv;
+}
+
+static apr_status_t get_certificates(server_rec *s, apr_pool_t *p, int fallback,
+                                     apr_array_header_t **pcert_files,
+                                     apr_array_header_t **pkey_files)
+{
+    apr_status_t rv = APR_ENOENT;
+    md_srv_conf_t *sc;
+    md_reg_t *reg;
+    md_store_t *store;
+    const md_t *md;
+    apr_array_header_t *key_files, *chain_files;
+    const char *keyfile, *chainfile;
+    int i;
+
+    *pkey_files = *pcert_files = NULL;
+    key_files = apr_array_make(p, 5, sizeof(const char*));
+    chain_files = apr_array_make(p, 5, sizeof(const char*));
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(10113)
+                 "get_certificates called for vhost %s.", s->server_hostname);
+
+    sc = md_config_get(s);
+    if (!sc) {
+        ap_log_error(APLOG_MARK, APLOG_TRACE2, 0, s,
+                     "asked for certificate of server %s which has no md config",
+                     s->server_hostname);
+        return APR_ENOENT;
+    }
+
+    assert(sc->mc);
+    reg = sc->mc->reg;
+    assert(reg);
+
+    sc->is_ssl = 1;
+
+    if (!sc->assigned) {
+        /* With the new hooks in mod_ssl, we are invoked for all server_rec. It is
+         * therefore normal, when we have nothing to add here. */
+        return APR_ENOENT;
+    }
+    else if (sc->assigned->nelts != 1) {
+        if (!fallback) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(10238)
+                         "conflict: %d MDs match Virtualhost %s which uses SSL, however "
+                         "there can be at most 1.",
+                         (int)sc->assigned->nelts, s->server_hostname);
+        }
+        return APR_EINVAL;
+    }
+    md = APR_ARRAY_IDX(sc->assigned, 0, const md_t*);
+
+    if (md->cert_files && md->cert_files->nelts) {
+        apr_array_cat(chain_files, md->cert_files);
+        apr_array_cat(key_files, md->pkey_files);
+        rv = APR_SUCCESS;
+    }
+    else {
+        md_pkey_spec_t *spec;
+        
+        for (i = 0; i < md_cert_count(md); ++i) {
+            spec = md_pkeys_spec_get(md->pks, i);
+            rv = md_reg_get_cred_files(&keyfile, &chainfile, reg, MD_SG_DOMAINS, md, spec, p);
+            if (APR_SUCCESS == rv) {
+                APR_ARRAY_PUSH(key_files, const char*) = keyfile;
+                APR_ARRAY_PUSH(chain_files, const char*) = chainfile;
+            }
+            else if (APR_STATUS_IS_ENOENT(rv)) {
+                /* certificate for this pkey is not available, others might
+                 * if pkeys have been added for a running mdomain.
+                 * see issue #260 */
+                rv = APR_SUCCESS;
+            }
+            else if (!APR_STATUS_IS_ENOENT(rv)) {
+                ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10110)
+                             "retrieving credentials for MD %s (%s)",
+                             md->name, md_pkey_spec_name(spec));
+                return rv;
+            }
+        }
+
+        if (md_array_is_empty(key_files)) {
+            if (fallback) {
+                /* Provide temporary, self-signed certificate as fallback, so that
+                 * clients do not get obscure TLS handshake errors or will see a fallback
+                 * virtual host that is not intended to be served here. */
+                char *kfn, *cfn;
+
+                store = md_reg_store_get(reg);
+                assert(store);
+
+                for (i = 0; i < md_cert_count(md); ++i) {
+                    spec = md_pkeys_spec_get(md->pks, i);
+                    fallback_fnames(p, spec, &kfn, &cfn);
+
+                    md_store_get_fname(&keyfile, store, MD_SG_DOMAINS, md->name, kfn, p);
+                    md_store_get_fname(&chainfile, store, MD_SG_DOMAINS, md->name, cfn, p);
+                    if (!md_file_exists(keyfile, p) || !md_file_exists(chainfile, p)) {
+                        if (APR_SUCCESS != (rv = make_fallback_cert(store, md, spec, s, p, kfn, cfn))) {
+                            return rv;
+                        }
+                    }
+                    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(10116)
+                                 "%s: providing %s fallback certificate for server %s",
+                                 md->name, md_pkey_spec_name(spec), s->server_hostname);
+                    APR_ARRAY_PUSH(key_files, const char*) = keyfile;
+                    APR_ARRAY_PUSH(chain_files, const char*) = chainfile;
+                }
+                rv = APR_EAGAIN;
+                goto leave;
+            }
+        }
+    }
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, s, APLOGNO(10077)
+                 "%s[state=%d]: providing certificates for server %s",
+                 md->name, md->state, s->server_hostname);
+leave:
+    if (!md_array_is_empty(key_files) && !md_array_is_empty(chain_files)) {
+        *pkey_files = key_files;
+        *pcert_files = chain_files;
+    }
+    else if (APR_SUCCESS == rv) {
+        rv = APR_ENOENT;
+    }
+    return rv;
+}
+
+static int md_add_cert_files(server_rec *s, apr_pool_t *p,
+                             apr_array_header_t *cert_files,
+                             apr_array_header_t *key_files)
+{
+    apr_array_header_t *md_cert_files;
+    apr_array_header_t *md_key_files;
+    apr_status_t rv;
+
+    ap_log_error(APLOG_MARK, APLOG_TRACE1, 0, s, "hook ssl_add_cert_files for %s",
+                 s->server_hostname);
+    rv = get_certificates(s, p, 0, &md_cert_files, &md_key_files);
+    if (APR_SUCCESS == rv) {
+        if (!apr_is_empty_array(cert_files)) {
+            /* downgraded fromm WARNING to DEBUG, since installing separate certificates
+             * may be a valid use case. */
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(10084)
+                         "host '%s' is covered by a Managed Domain, but "
+                         "certificate/key files are already configured "
+                         "for it (most likely via SSLCertificateFile).",
+                         s->server_hostname);
+        }
+        ap_log_error(APLOG_MARK, APLOG_TRACE1, 0, s,
+                     "host '%s' is covered by a Managed Domaina and "
+                     "is being provided with %d key/certificate files.",
+                     s->server_hostname, md_cert_files->nelts);
+        apr_array_cat(cert_files, md_cert_files);
+        apr_array_cat(key_files, md_key_files);
+        return DONE;
+    }
+    return DECLINED;
+}
+
+static int md_add_fallback_cert_files(server_rec *s, apr_pool_t *p,
+                                      apr_array_header_t *cert_files,
+                                      apr_array_header_t *key_files)
+{
+    apr_array_header_t *md_cert_files;
+    apr_array_header_t *md_key_files;
+    apr_status_t rv;
+
+    ap_log_error(APLOG_MARK, APLOG_TRACE1, 0, s, "hook ssl_add_fallback_cert_files for %s",
+                 s->server_hostname);
+    rv = get_certificates(s, p, 1, &md_cert_files, &md_key_files);
+    if (APR_EAGAIN == rv) {
+        apr_array_cat(cert_files, md_cert_files);
+        apr_array_cat(key_files, md_key_files);
+        return DONE;
+    }
+    return DECLINED;
+}
+
+static int md_answer_challenge(conn_rec *c, const char *servername,
+                               const char **pcert_pem, const char **pkey_pem)
+{
+    const char *protocol;
+    int hook_rv = DECLINED;
+    apr_status_t rv = APR_ENOENT;
+    md_srv_conf_t *sc;
+    md_store_t *store;
+    char *cert_name, *pkey_name;
+    const char *cert_pem, *key_pem;
+    int i;
+
+    if (!servername
+        || !(protocol = md_protocol_get(c))
+        || strcmp(PROTO_ACME_TLS_1, protocol)) {
+        goto cleanup;
+    }
+    sc = md_config_get(c->base_server);
+    if (!sc || !sc->mc->reg) goto cleanup;
+
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c,
+                  "Answer challenge[tls-alpn-01] for %s", servername);
+    store = md_reg_store_get(sc->mc->reg);
+
+    for (i = 0; i < md_pkeys_spec_count( sc->pks ); i++) {
+        tls_alpn01_fnames(c->pool, md_pkeys_spec_get(sc->pks,i),
+                          &pkey_name, &cert_name);
+
+        rv = md_store_load(store, MD_SG_CHALLENGES, servername, cert_name, MD_SV_TEXT,
+                           (void**)&cert_pem, c->pool);
+        if (APR_STATUS_IS_ENOENT(rv)) continue;
+        if (APR_SUCCESS != rv) goto cleanup;
+
+        rv = md_store_load(store, MD_SG_CHALLENGES, servername, pkey_name, MD_SV_TEXT,
+                           (void**)&key_pem, c->pool);
+        if (APR_STATUS_IS_ENOENT(rv)) continue;
+        if (APR_SUCCESS != rv) goto cleanup;
+
+        ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c,
+                      "Found challenge cert %s, key %s for %s",
+                      cert_name, pkey_name, servername);
+        *pcert_pem = cert_pem;
+        *pkey_pem = key_pem;
+        hook_rv = OK;
+        break;
+    }
+
+    if (DECLINED == hook_rv) {
+        ap_log_cerror(APLOG_MARK, APLOG_INFO, rv, c, APLOGNO(10080)
+                      "%s: unknown tls-alpn-01 challenge host", servername);
+    }
+
+cleanup:
+    return hook_rv;
+}
+
+
+/**************************************************************************************************/
+/* ACME 'http-01' challenge responses */
+
+#define WELL_KNOWN_PREFIX           "/.well-known/"
+#define ACME_CHALLENGE_PREFIX       WELL_KNOWN_PREFIX"acme-challenge/"
+
+static int md_http_challenge_pr(request_rec *r)
+{
+    apr_bucket_brigade *bb;
+    const md_srv_conf_t *sc;
+    const char *name, *data;
+    md_reg_t *reg;
+    const md_t *md;
+    apr_status_t rv;
+
+    if (r->parsed_uri.path
+        && !strncmp(ACME_CHALLENGE_PREFIX, r->parsed_uri.path, sizeof(ACME_CHALLENGE_PREFIX)-1)) {
+        sc = ap_get_module_config(r->server->module_config, &md_module);
+        if (sc && sc->mc) {
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
+                          "access inside /.well-known/acme-challenge for %s%s",
+                          r->hostname, r->parsed_uri.path);
+            md = md_get_by_domain(sc->mc->mds, r->hostname);
+            name = r->parsed_uri.path + sizeof(ACME_CHALLENGE_PREFIX)-1;
+            reg = sc && sc->mc? sc->mc->reg : NULL;
+
+            if (md && md->ca_challenges
+                && md_array_str_index(md->ca_challenges, MD_AUTHZ_CHA_HTTP_01, 0, 1) < 0) {
+                /* The MD this challenge is for does not allow http-01 challanges,
+                 * we have to decline. See #279 for a setup example where this
+                 * is necessary.
+                 */
+                return DECLINED;
+            }
+
+            if (strlen(name) && !ap_strchr_c(name, '/') && reg) {
+                md_store_t *store = md_reg_store_get(reg);
+
+                rv = md_store_load(store, MD_SG_CHALLENGES, r->hostname,
+                                   MD_FN_HTTP01, MD_SV_TEXT, (void**)&data, r->pool);
+                ap_log_rerror(APLOG_MARK, APLOG_DEBUG, rv, r,
+                              "loading challenge for %s (%s)", r->hostname, r->uri);
+                if (APR_SUCCESS == rv) {
+                    apr_size_t len = strlen(data);
+
+                    if (r->method_number != M_GET) {
+                        return HTTP_NOT_IMPLEMENTED;
+                    }
+                    /* A GET on a challenge resource for a hostname we are
+                     * configured for. Let's send the content back */
+                    r->status = HTTP_OK;
+                    apr_table_setn(r->headers_out, "Content-Length", apr_ltoa(r->pool, (long)len));
+
+                    bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
+                    apr_brigade_write(bb, NULL, NULL, data, len);
+                    ap_pass_brigade(r->output_filters, bb);
+                    apr_brigade_cleanup(bb);
+
+                    return DONE;
+                }
+                else if (!md || md->renew_mode == MD_RENEW_MANUAL
+                    || (md->cert_files && md->cert_files->nelts
+                        && md->renew_mode == MD_RENEW_AUTO)) {
+                    /* The request hostname is not for a domain - or at least not for
+                     * a domain that we renew ourselves. We are not
+                     * the sole authority here for /.well-known/acme-challenge (see PR62189).
+                     * So, we decline to handle this and give others a chance to provide
+                     * the answer.
+                     */
+                    return DECLINED;
+                }
+                else if (APR_STATUS_IS_ENOENT(rv)) {
+                    return HTTP_NOT_FOUND;
+                }
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(10081)
+                              "loading challenge %s from store", name);
+                return HTTP_INTERNAL_SERVER_ERROR;
+            }
+        }
+    }
+    return DECLINED;
+}
+
+/**************************************************************************************************/
+/* Require Https hook */
+
+static int md_require_https_maybe(request_rec *r)
+{
+    const md_srv_conf_t *sc;
+    apr_uri_t uri;
+    const char *s, *host;
+    const md_t *md;
+    int status;
+
+    /* Requests outside the /.well-known path are subject to possible
+     * https: redirects or HSTS header additions.
+     */
+    sc = ap_get_module_config(r->server->module_config, &md_module);
+    if (!sc || !sc->assigned || !sc->assigned->nelts || !r->parsed_uri.path
+        || !strncmp(WELL_KNOWN_PREFIX, r->parsed_uri.path, sizeof(WELL_KNOWN_PREFIX)-1)) {
+        goto declined;
+    }
+
+    host = ap_get_server_name_for_url(r);
+    md = md_get_for_domain(r->server, host);
+    if (!md) goto declined;
+
+    if (ap_ssl_conn_is_ssl(r->connection)) {
+        /* Using https:
+         * if 'permanent' and no one else set a HSTS header already, do it */
+        if (md->require_https == MD_REQUIRE_PERMANENT
+            && sc->mc->hsts_header && !apr_table_get(r->headers_out, MD_HSTS_HEADER)) {
+            apr_table_setn(r->headers_out, MD_HSTS_HEADER, sc->mc->hsts_header);
+        }
+    }
+    else {
+        if (md->require_https > MD_REQUIRE_OFF) {
+            /* Not using https:, but require it. Redirect. */
+            if (r->method_number == M_GET) {
+                /* safe to use the old-fashioned codes */
+                status = ((MD_REQUIRE_PERMANENT == md->require_https)?
+                          HTTP_MOVED_PERMANENTLY : HTTP_MOVED_TEMPORARILY);
+            }
+            else {
+                /* these should keep the method unchanged on retry */
+                status = ((MD_REQUIRE_PERMANENT == md->require_https)?
+                          HTTP_PERMANENT_REDIRECT : HTTP_TEMPORARY_REDIRECT);
+            }
+
+            s = ap_construct_url(r->pool, r->uri, r);
+            if (APR_SUCCESS == apr_uri_parse(r->pool, s, &uri)) {
+                uri.scheme = (char*)"https";
+                uri.port = 443;
+                uri.port_str = (char*)"443";
+                uri.query = r->parsed_uri.query;
+                uri.fragment = r->parsed_uri.fragment;
+                s = apr_uri_unparse(r->pool, &uri, APR_URI_UNP_OMITUSERINFO);
+                if (s && *s) {
+                    apr_table_setn(r->headers_out, "Location", s);
+                    return status;
+                }
+            }
+        }
+    }
+declined:
+    return DECLINED;
+}
+
+/* Runs once per created child process. Perform any process
+ * related initialization here.
+ */
+static void md_child_init(apr_pool_t *pool, server_rec *s)
+{
+    (void)pool;
+    (void)s;
+}
+
+/* Install this module into the apache2 infrastructure.
+ */
+static void md_hooks(apr_pool_t *pool)
+{
+    static const char *const mod_ssl[] = { "mod_ssl.c", "mod_tls.c", NULL};
+    static const char *const mod_wd[] = { "mod_watchdog.c", NULL};
+
+    /* Leave the ssl initialization to mod_ssl or friends. */
+    md_acme_init(pool, AP_SERVER_BASEVERSION, 0);
+
+    ap_log_perror(APLOG_MARK, APLOG_TRACE1, 0, pool, "installing hooks");
+
+    /* Run once after configuration is set, before mod_ssl.
+     * Run again after mod_ssl is done.
+     */
+    ap_hook_post_config(md_post_config_before_ssl, NULL, mod_ssl, APR_HOOK_MIDDLE);
+    ap_hook_post_config(md_post_config_after_ssl, mod_ssl, mod_wd, APR_HOOK_LAST);
+
+    /* Run once after a child process has been created.
+     */
+    ap_hook_child_init(md_child_init, NULL, mod_ssl, APR_HOOK_MIDDLE);
+
+    /* answer challenges *very* early, before any configured authentication may strike */
+    ap_hook_post_read_request(md_require_https_maybe, mod_ssl, NULL, APR_HOOK_MIDDLE);
+    ap_hook_post_read_request(md_http_challenge_pr, NULL, NULL, APR_HOOK_MIDDLE);
+
+    ap_hook_protocol_propose(md_protocol_propose, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_protocol_switch(md_protocol_switch, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_protocol_get(md_protocol_get, NULL, NULL, APR_HOOK_MIDDLE);
+
+    /* Status request handlers and contributors */
+    ap_hook_post_read_request(md_http_cert_status, NULL, mod_ssl, APR_HOOK_MIDDLE);
+    APR_OPTIONAL_HOOK(ap, status_hook, md_domains_status_hook, NULL, NULL, APR_HOOK_MIDDLE);
+    APR_OPTIONAL_HOOK(ap, status_hook, md_ocsp_status_hook, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_handler(md_status_handler, NULL, NULL, APR_HOOK_MIDDLE);
+
+    ap_hook_ssl_answer_challenge(md_answer_challenge, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_ssl_add_cert_files(md_add_cert_files, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_ssl_add_fallback_cert_files(md_add_fallback_cert_files, NULL, NULL, APR_HOOK_MIDDLE);
+
+#if AP_MODULE_MAGIC_AT_LEAST(20120211, 105)
+    ap_hook_ssl_ocsp_prime_hook(md_ocsp_prime_status, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_ssl_ocsp_get_resp_hook(md_ocsp_provide_status, NULL, NULL, APR_HOOK_MIDDLE);
+#else
+#error "This version of mod_md requires Apache httpd 2.4.48 or newer."
+#endif /* AP_MODULE_MAGIC_AT_LEAST() */
+}
+
diff --git a/modules/md/mod_md.dep b/modules/md/mod_md.dep
new file mode 100644
index 0000000..0cbd691
--- /dev/null
+++ b/modules/md/mod_md.dep
@@ -0,0 +1,5 @@
+# Microsoft Developer Studio Generated Dependency File, included by mod_md.mak

+

+..\..\build\win32\httpd.rc : \

+	"..\..\include\ap_release.h"\

+	

diff --git a/modules/md/mod_md.dsp b/modules/md/mod_md.dsp
new file mode 100644
index 0000000..d99fb1c
--- /dev/null
+++ b/modules/md/mod_md.dsp
@@ -0,0 +1,223 @@
+# Microsoft Developer Studio Project File - Name="mod_md" - Package Owner=<4>

+# Microsoft Developer Studio Generated Build File, Format Version 6.00

+# ** DO NOT EDIT **

+

+# TARGTYPE "Win32 (x86) Dynamic-Link Library" 0x0102

+

+CFG=mod_md - Win32 Release

+!MESSAGE This is not a valid makefile. To build this project using NMAKE,

+!MESSAGE use the Export Makefile command and run

+!MESSAGE 

+!MESSAGE NMAKE /f "mod_md.mak".

+!MESSAGE 

+!MESSAGE You can specify a configuration when running NMAKE

+!MESSAGE by defining the macro CFG on the command line. For example:

+!MESSAGE 

+!MESSAGE NMAKE /f "mod_md.mak" CFG="mod_md - Win32 Release"

+!MESSAGE 

+!MESSAGE Possible choices for configuration are:

+!MESSAGE 

+!MESSAGE "mod_md - Win32 Release" (based on "Win32 (x86) Dynamic-Link Library")

+!MESSAGE "mod_md - Win32 Debug" (based on "Win32 (x86) Dynamic-Link Library")

+!MESSAGE 

+

+# Begin Project

+# PROP AllowPerConfigDependencies 0

+# PROP Scc_ProjName ""

+# PROP Scc_LocalPath ""

+CPP=cl.exe

+MTL=midl.exe

+RSC=rc.exe

+

+!IF  "$(CFG)" == "mod_md - Win32 Release"

+

+# PROP BASE Use_MFC 0

+# PROP BASE Use_Debug_Libraries 0

+# PROP BASE Output_Dir "Release"

+# PROP BASE Intermediate_Dir "Release"

+# PROP BASE Target_Dir ""

+# PROP Use_MFC 0

+# PROP Use_Debug_Libraries 0

+# PROP Output_Dir "Release"

+# PROP Intermediate_Dir "Release"

+# PROP Ignore_Export_Lib 0

+# PROP Target_Dir ""

+# ADD BASE CPP /nologo /MD /W3 /O2 /D "WIN32" /D "NDEBUG" /D "_WINDOWS" /D "ssize_t=long" /FD /c

+# ADD CPP /nologo /MD /W3 /O2 /Oy- /Zi /I "../../server/mpm/winnt" "/I ../ssl" /I "../../include" /I "../generators" /I "../../srclib/apr/include" /I "../../srclib/apr-util/include" /I "../../srclib/openssl/inc32" /I "../../srclib/jansson/include" /I "../../srclib/curl/include" /I "../core"   /D "NDEBUG" /D "WIN32" /D "_WINDOWS" /D "ssize_t=long" /Fd"Release\mod_md_src" /FD /c

+# ADD BASE MTL /nologo /D "NDEBUG" /win32

+# ADD MTL /nologo /D "NDEBUG" /mktyplib203 /win32

+# ADD BASE RSC /l 0x409 /d "NDEBUG"

+# ADD RSC /l 0x409 /fo"Release/mod_md.res" /i "../../include" /i "../../srclib/apr/include" /d "NDEBUG" /d "BIN_NAME=mod_md.so" /d "LONG_NAME=Letsencrypt module for Apache"

+BSC32=bscmake.exe

+# ADD BASE BSC32 /nologo

+# ADD BSC32 /nologo

+LINK32=link.exe

+# ADD BASE LINK32 kernel32.lib /nologo /subsystem:windows /dll /out:".\Release\mod_md.so" /base:@..\..\os\win32\BaseAddr.ref,mod_md.so

+# ADD LINK32 kernel32.lib libhttpd.lib libapr-1.lib libaprutil-1.lib ssleay32.lib libeay32.lib jansson.lib libcurl.lib /libpath:"../../srclib/apr/Release" /libpath:"../../srclib/apr-util/Release" /libpath:"../../Release/" /libpath:"../../srclib/openssl/out32dll" /libpath:"../../srclib/jansson/lib" /libpath:"../../srclib/curl/lib" /nologo /subsystem:windows /dll /incremental:no /debug /out:".\Release\mod_md.so" /base:@..\..\os\win32\BaseAddr.ref,mod_md.so /opt:ref

+# Begin Special Build Tool

+TargetPath=.\Release\mod_md.so

+SOURCE="$(InputPath)"

+PostBuild_Desc=Embed .manifest

+PostBuild_Cmds=if exist $(TargetPath).manifest mt.exe -manifest $(TargetPath).manifest -outputresource:$(TargetPath);2

+# End Special Build Tool

+

+!ELSEIF  "$(CFG)" == "mod_md - Win32 Debug"

+

+# PROP BASE Use_MFC 0

+# PROP BASE Use_Debug_Libraries 1

+# PROP BASE Output_Dir "Debug"

+# PROP BASE Intermediate_Dir "Debug"

+# PROP BASE Target_Dir ""

+# PROP Use_MFC 0

+# PROP Use_Debug_Libraries 1

+# PROP Output_Dir "Debug"

+# PROP Intermediate_Dir "Debug"

+# PROP Ignore_Export_Lib 0

+# PROP Target_Dir ""

+# ADD BASE CPP /nologo /MDd /W3 /EHsc /Zi /Od /D "WIN32" /D "_DEBUG" /D "_WINDOWS" /D "ssize_t=long" /FD /c

+# ADD CPP /nologo /MDd /W3 /EHsc /Zi /Od /I "../ssl" /I "../../include" /I "../../srclib/apr/include" /I "../generators" /I "../../srclib/apr-util/include" /I "../../srclib/openssl/inc32" /I "../../srclib/jansson/include" /I "../../srclib/curl/include" /I "../core" /src" /D "_DEBUG" /D "WIN32" /D "_WINDOWS" /D "ssize_t=long" /Fd"Debug\mod_md_src" /FD /c

+# ADD BASE MTL /nologo /D "_DEBUG" /win32

+# ADD MTL /nologo /D "_DEBUG" /mktyplib203 /win32

+# ADD BASE RSC /l 0x409 /d "_DEBUG"

+# ADD RSC /l 0x409 /fo"Debug/mod_md.res" /i "../../include" /i "../../srclib/apr/include" /d "_DEBUG" /d "BIN_NAME=mod_md.so" /d "LONG_NAME=md_module for Apache"

+BSC32=bscmake.exe

+# ADD BASE BSC32 /nologo

+# ADD BSC32 /nologo

+LINK32=link.exe

+# ADD BASE LINK32 kernel32.lib /nologo /subsystem:windows /dll /incremental:no /debug /out:".\Debug\mod_md.so" /base:@..\..\os\win32\BaseAddr.ref,mod_md.so

+# ADD LINK32 kernel32.lib libhttpd.lib libapr-1.lib libaprutil-1.lib ssleay32.lib libeay32.lib jansson_d.lib libcurl_debug.lib /nologo /subsystem:windows /dll /libpath:"../../srclib/openssl/out32dll" /libpath:"../../srclib/jansson/lib" /libpath:"../../srclib/curl/lib" /incremental:no /debug /out:".\Debug\mod_md.so" /base:@..\..\os\win32\BaseAddr.ref,mod_md.so

+# Begin Special Build Tool

+TargetPath=.\Debug\mod_md.so

+SOURCE="$(InputPath)"

+PostBuild_Desc=Embed .manifest

+PostBuild_Cmds=if exist $(TargetPath).manifest mt.exe -manifest $(TargetPath).manifest -outputresource:$(TargetPath);2

+# End Special Build Tool

+

+!ENDIF 

+

+# Begin Target

+

+# Name "mod_md - Win32 Release"

+# Name "mod_md - Win32 Debug"

+# Begin Source File

+

+SOURCE=./mod_md.c

+# End Source File

+# Begin Source File

+

+SOURCE=./mod_md_config.c

+# End Source File

+# Begin Source File

+

+SOURCE=./mod_md_drive.c

+# End Source File

+# Begin Source File

+

+SOURCE=./mod_md_ocsp.c

+# End Source File

+# Begin Source File

+

+SOURCE=./mod_md_os.c

+# End Source File

+# Begin Source File

+

+SOURCE=./mod_md_status.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_acme.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_acme_acct.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_acme_authz.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_acme_drive.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_acme_order.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_acmev2_drive.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_core.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_crypt.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_curl.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_http.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_event.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_json.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_jws.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_log.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_ocsp.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_reg.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_result.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_status.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_store.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_store_fs.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_tailscale.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_time.c

+# End Source File

+# Begin Source File

+

+SOURCE=./md_util.c

+# End Source File

+# Begin Source File

+

+SOURCE=..\..\build\win32\httpd.rc

+# End Source File

+# End Target

+# End Project

diff --git a/modules/md/mod_md.h b/modules/md/mod_md.h
new file mode 100644
index 0000000..805737d
--- /dev/null
+++ b/modules/md/mod_md.h
@@ -0,0 +1,20 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_mod_md_h
+#define mod_md_mod_md_h
+
+#endif /* mod_md_mod_md_h */
diff --git a/modules/md/mod_md.mak b/modules/md/mod_md.mak
new file mode 100644
index 0000000..9779e6b
--- /dev/null
+++ b/modules/md/mod_md.mak
@@ -0,0 +1,618 @@
+# Microsoft Developer Studio Generated NMAKE File, Based on mod_md.dsp

+!IF "$(CFG)" == ""

+CFG=mod_md - Win32 Release

+!MESSAGE No configuration specified. Defaulting to mod_md - Win32 Release.

+!ENDIF 

+

+!IF "$(CFG)" != "mod_md - Win32 Release" && "$(CFG)" != "mod_md - Win32 Debug"

+!MESSAGE Invalid configuration "$(CFG)" specified.

+!MESSAGE You can specify a configuration when running NMAKE

+!MESSAGE by defining the macro CFG on the command line. For example:

+!MESSAGE 

+!MESSAGE NMAKE /f "mod_md.mak" CFG="mod_md - Win32 Release"

+!MESSAGE 

+!MESSAGE Possible choices for configuration are:

+!MESSAGE 

+!MESSAGE "mod_md - Win32 Release" (based on "Win32 (x86) Dynamic-Link Library")

+!MESSAGE "mod_md - Win32 Debug" (based on "Win32 (x86) Dynamic-Link Library")

+!MESSAGE 

+!ERROR An invalid configuration is specified.

+!ENDIF 

+

+!IF "$(OS)" == "Windows_NT"

+NULL=

+!ELSE 

+NULL=nul

+!ENDIF 

+

+!IF "$(_HAVE_OSSL110)" == "1"

+SSLCRP=libcrypto

+SSLLIB=libssl

+SSLINC=/I ../../srclib/openssl/include

+SSLBIN=/libpath:../../srclib/openssl

+!ELSE 

+SSLCRP=libeay32

+SSLLIB=ssleay32

+SSLINC=/I ../../srclib/openssl/inc32

+SSLBIN=/libpath:../../srclib/openssl/out32dll

+!ENDIF 

+

+!IF  "$(CFG)" == "mod_md - Win32 Release"

+

+OUTDIR=.\Release

+INTDIR=.\Release

+# Begin Custom Macros

+OutDir=.\Release

+# End Custom Macros

+

+!IF "$(RECURSE)" == "0" 

+

+ALL : "$(OUTDIR)\mod_md.so"

+

+!ELSE 

+

+ALL : "libhttpd - Win32 Release" "libaprutil - Win32 Release" "libapr - Win32 Release" "$(OUTDIR)\mod_md.so"

+

+!ENDIF 

+

+!IF "$(RECURSE)" == "1" 

+CLEAN :"libapr - Win32 ReleaseCLEAN" "libaprutil - Win32 ReleaseCLEAN" "libhttpd - Win32 ReleaseCLEAN" 

+!ELSE 

+CLEAN :

+!ENDIF 

+	-@erase "$(INTDIR)\md_acme.obj"

+	-@erase "$(INTDIR)\md_acme_acct.obj"

+	-@erase "$(INTDIR)\md_acme_authz.obj"

+	-@erase "$(INTDIR)\md_acme_drive.obj"

+	-@erase "$(INTDIR)\md_acme_order.obj"

+	-@erase "$(INTDIR)\md_acmev2_drive.obj"

+	-@erase "$(INTDIR)\md_core.obj"

+	-@erase "$(INTDIR)\md_crypt.obj"

+	-@erase "$(INTDIR)\md_curl.obj"

+	-@erase "$(INTDIR)\md_event.obj"

+	-@erase "$(INTDIR)\md_http.obj"

+	-@erase "$(INTDIR)\md_json.obj"

+	-@erase "$(INTDIR)\md_jws.obj"

+	-@erase "$(INTDIR)\md_log.obj"

+	-@erase "$(INTDIR)\md_ocsp.obj"

+	-@erase "$(INTDIR)\md_reg.obj"

+	-@erase "$(INTDIR)\md_result.obj"

+	-@erase "$(INTDIR)\md_status.obj"

+	-@erase "$(INTDIR)\md_store.obj"

+	-@erase "$(INTDIR)\md_store_fs.obj"

+	-@erase "$(INTDIR)\md_tailscale.obj"

+	-@erase "$(INTDIR)\md_time.obj"

+	-@erase "$(INTDIR)\md_util.obj"

+	-@erase "$(INTDIR)\mod_md.obj"

+	-@erase "$(INTDIR)\mod_md.res"

+	-@erase "$(INTDIR)\mod_md_config.obj"

+	-@erase "$(INTDIR)\mod_md_drive.obj"

+	-@erase "$(INTDIR)\mod_md_status.obj"

+	-@erase "$(INTDIR)\mod_md_ocsp.obj"

+	-@erase "$(INTDIR)\mod_md_os.obj"

+	-@erase "$(INTDIR)\mod_md_src.idb"

+	-@erase "$(INTDIR)\mod_md_src.pdb"

+	-@erase "$(OUTDIR)\mod_md.exp"

+	-@erase "$(OUTDIR)\mod_md.lib"

+	-@erase "$(OUTDIR)\mod_md.pdb"

+	-@erase "$(OUTDIR)\mod_md.so"

+

+"$(OUTDIR)" :

+    if not exist "$(OUTDIR)/$(NULL)" mkdir "$(OUTDIR)"

+

+CPP=cl.exe

+CPP_PROJ=/nologo /MD /W3 /Zi /O2 /Oy- /I "../../server/mpm/winnt" /I "../../include" /I "../../srclib/apr/include" /I "../../srclib/apr-util/include" $(SSLINC) /I "../../srclib/jansson/include" /I "../../srclib/curl/include" /I "../ssl" /I "../core" /I "../generators" /D "NDEBUG" /D "WIN32" /D "_WINDOWS" /D ssize_t=long /Fo"$(INTDIR)\\" /Fd"$(INTDIR)\mod_md_src" /FD /I " ../ssl" /c 

+

+.c{$(INTDIR)}.obj::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.cpp{$(INTDIR)}.obj::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.cxx{$(INTDIR)}.obj::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.c{$(INTDIR)}.sbr::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.cpp{$(INTDIR)}.sbr::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.cxx{$(INTDIR)}.sbr::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+MTL=midl.exe

+MTL_PROJ=/nologo /D "NDEBUG" /mktyplib203 /win32 

+RSC=rc.exe

+RSC_PROJ=/l 0x409 /fo"$(INTDIR)\mod_md.res" /i "../../include" /i "../../srclib/apr/include" /d "NDEBUG" /d BIN_NAME=mod_md.so /d LONG_NAME=Letsencrypt module for Apache 

+BSC32=bscmake.exe

+BSC32_FLAGS=/nologo /o"$(OUTDIR)\mod_md.bsc" 

+BSC32_SBRS= \

+	

+LINK32=link.exe

+LINK32_FLAGS=kernel32.lib libhttpd.lib libapr-1.lib libaprutil-1.lib $(SSLCRP).lib $(SSLLIB).lib jansson.lib libcurl.lib /nologo /subsystem:windows /dll /incremental:no /pdb:"$(OUTDIR)\mod_md.pdb" /debug  /out:"$(OUTDIR)\mod_md.so" /implib:"$(OUTDIR)\mod_md.lib" /libpath:"../../srclib/apr/Release" /libpath:"../../srclib/apr-util/Release" /libpath:"../../Release/" $(SSLBIN) /libpath:"../../srclib/jansson/lib" /libpath:"../../srclib/curl/lib" /base:@..\..\os\win32\BaseAddr.ref,mod_md.so /opt:ref 

+LINK32_OBJS= \

+	"$(INTDIR)\mod_md.obj" \

+	"$(INTDIR)\mod_md_config.obj" \

+	"$(INTDIR)\mod_md_drive.obj" \

+	"$(INTDIR)\mod_md_ocsp.obj" \

+	"$(INTDIR)\mod_md_os.obj" \

+	"$(INTDIR)\mod_md_status.obj" \

+	"$(INTDIR)\md_core.obj" \

+	"$(INTDIR)\md_crypt.obj" \

+	"$(INTDIR)\md_curl.obj" \

+	"$(INTDIR)\md_event.obj" \

+	"$(INTDIR)\md_http.obj" \

+	"$(INTDIR)\md_json.obj" \

+	"$(INTDIR)\md_jws.obj" \

+	"$(INTDIR)\md_log.obj" \

+	"$(INTDIR)\md_ocsp.obj" \

+	"$(INTDIR)\md_reg.obj" \

+	"$(INTDIR)\md_result.obj" \

+	"$(INTDIR)\md_status.obj" \

+	"$(INTDIR)\md_store.obj" \

+	"$(INTDIR)\md_store_fs.obj" \

+	"$(INTDIR)\md_tailscale.obj" \

+	"$(INTDIR)\md_time.obj" \

+	"$(INTDIR)\md_util.obj" \

+	"$(INTDIR)\md_acme.obj" \

+	"$(INTDIR)\md_acme_acct.obj" \

+	"$(INTDIR)\md_acme_authz.obj" \

+	"$(INTDIR)\md_acme_drive.obj" \

+	"$(INTDIR)\md_acme_order.obj" \

+	"$(INTDIR)\md_acmev2_drive.obj" \

+	"$(INTDIR)\mod_md.res" \

+	"..\..\srclib\apr\Release\libapr-1.lib" \

+	"..\..\srclib\apr-util\Release\libaprutil-1.lib" \

+	"..\..\Release\libhttpd.lib"

+

+"$(OUTDIR)\mod_md.so" : "$(OUTDIR)" $(DEF_FILE) $(LINK32_OBJS)

+    $(LINK32) @<<

+  $(LINK32_FLAGS) $(LINK32_OBJS)

+<<

+

+TargetPath=.\Release\mod_md.so

+SOURCE="$(InputPath)"

+PostBuild_Desc=Embed .manifest

+DS_POSTBUILD_DEP=$(INTDIR)\postbld.dep

+

+ALL : $(DS_POSTBUILD_DEP)

+

+# Begin Custom Macros

+OutDir=.\Release

+# End Custom Macros

+

+$(DS_POSTBUILD_DEP) : "libhttpd - Win32 Release" "libaprutil - Win32 Release" "libapr - Win32 Release" "$(OUTDIR)\mod_md.so"

+   if exist .\Release\mod_md.so.manifest mt.exe -manifest .\Release\mod_md.so.manifest -outputresource:.\Release\mod_md.so;2

+	echo Helper for Post-build step > "$(DS_POSTBUILD_DEP)"

+

+!ELSEIF  "$(CFG)" == "mod_md - Win32 Debug"

+

+OUTDIR=.\Debug

+INTDIR=.\Debug

+# Begin Custom Macros

+OutDir=.\Debug

+# End Custom Macros

+

+!IF "$(RECURSE)" == "0" 

+

+ALL : "$(OUTDIR)\mod_md.so"

+

+!ELSE 

+

+ALL : "libhttpd - Win32 Debug" "libaprutil - Win32 Debug" "libapr - Win32 Debug" "$(OUTDIR)\mod_md.so"

+

+!ENDIF 

+

+!IF "$(RECURSE)" == "1" 

+CLEAN :"libapr - Win32 DebugCLEAN" "libaprutil - Win32 DebugCLEAN" "libhttpd - Win32 DebugCLEAN" 

+!ELSE 

+CLEAN :

+!ENDIF 

+	-@erase "$(INTDIR)\md_acme.obj"

+	-@erase "$(INTDIR)\md_acme_acct.obj"

+	-@erase "$(INTDIR)\md_acme_authz.obj"

+	-@erase "$(INTDIR)\md_acme_drive.obj"

+	-@erase "$(INTDIR)\md_acme_order.obj"

+	-@erase "$(INTDIR)\md_acmev2_drive.obj"

+	-@erase "$(INTDIR)\md_core.obj"

+	-@erase "$(INTDIR)\md_crypt.obj"

+	-@erase "$(INTDIR)\md_curl.obj"

+	-@erase "$(INTDIR)\md_event.obj"

+	-@erase "$(INTDIR)\md_http.obj"

+	-@erase "$(INTDIR)\md_json.obj"

+	-@erase "$(INTDIR)\md_jws.obj"

+	-@erase "$(INTDIR)\md_log.obj"

+	-@erase "$(INTDIR)\md_ocsp.obj"

+	-@erase "$(INTDIR)\md_reg.obj"

+	-@erase "$(INTDIR)\md_result.obj"

+	-@erase "$(INTDIR)\md_status.obj"

+	-@erase "$(INTDIR)\md_store.obj"

+	-@erase "$(INTDIR)\md_store_fs.obj"

+	-@erase "$(INTDIR)\md_tailscale.obj"

+	-@erase "$(INTDIR)\md_time.obj"

+	-@erase "$(INTDIR)\md_util.obj"

+	-@erase "$(INTDIR)\mod_md.obj"

+	-@erase "$(INTDIR)\mod_md.res"

+	-@erase "$(INTDIR)\mod_md_config.obj"

+	-@erase "$(INTDIR)\mod_md_drive.obj"

+	-@erase "$(INTDIR)\mod_md_status.obj"

+	-@erase "$(INTDIR)\mod_md_ocsp.obj"

+	-@erase "$(INTDIR)\mod_md_os.obj"

+	-@erase "$(INTDIR)\mod_md_src.idb"

+	-@erase "$(INTDIR)\mod_md_src.pdb"

+	-@erase "$(OUTDIR)\mod_md.exp"

+	-@erase "$(OUTDIR)\mod_md.lib"

+	-@erase "$(OUTDIR)\mod_md.pdb"

+	-@erase "$(OUTDIR)\mod_md.so"

+

+"$(OUTDIR)" :

+    if not exist "$(OUTDIR)/$(NULL)" mkdir "$(OUTDIR)"

+

+CPP=cl.exe

+CPP_PROJ=/nologo /MDd /W3 /Zi /Od /I "../../include" /I "../../srclib/apr/include" /I "../../srclib/apr-util/include" $(SSLINC) /I "../../srclib/jansson/include" /I "../../srclib/curl/include" /I "../core" /I "../generators" /I "../ssl" /D "_DEBUG" /D "WIN32" /D "_WINDOWS" /D ssize_t=long /Fo"$(INTDIR)\\" /Fd"$(INTDIR)\mod_md_src" /FD /EHsc /c 

+

+.c{$(INTDIR)}.obj::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.cpp{$(INTDIR)}.obj::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.cxx{$(INTDIR)}.obj::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.c{$(INTDIR)}.sbr::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.cpp{$(INTDIR)}.sbr::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+.cxx{$(INTDIR)}.sbr::

+   $(CPP) @<<

+   $(CPP_PROJ) $< 

+<<

+

+MTL=midl.exe

+MTL_PROJ=/nologo /D "_DEBUG" /mktyplib203 /win32 

+RSC=rc.exe

+RSC_PROJ=/l 0x409 /fo"$(INTDIR)\mod_md.res" /i "../../include" /i "../../srclib/apr/include" /d "_DEBUG" /d BIN_NAME=mod_md.so /d LONG_NAME=http2_module for Apache 

+BSC32=bscmake.exe

+BSC32_FLAGS=/nologo /o"$(OUTDIR)\mod_md.bsc" 

+BSC32_SBRS= \

+	

+LINK32=link.exe

+LINK32_FLAGS=kernel32.lib libhttpd.lib libapr-1.lib libaprutil-1.lib $(SSLCRP).lib $(SSLLIB).lib jansson_d.lib libcurl_debug.lib /nologo /subsystem:windows /dll /incremental:no /pdb:"$(OUTDIR)\mod_md.pdb" /debug  /out:"$(OUTDIR)\mod_md.so" /implib:"$(OUTDIR)\mod_md.lib" $(SSLBIN) /libpath:"../../srclib/jansson/lib" /libpath:"../../srclib/curl/lib" /base:@..\..\os\win32\BaseAddr.ref,mod_md.so 

+LINK32_OBJS= \

+	"$(INTDIR)\mod_md.obj" \

+	"$(INTDIR)\mod_md_config.obj" \

+	"$(INTDIR)\mod_md_drive.obj" \

+	"$(INTDIR)\mod_md_ocsp.obj" \

+	"$(INTDIR)\mod_md_os.obj" \

+	"$(INTDIR)\mod_md_status.obj" \

+	"$(INTDIR)\md_core.obj" \

+	"$(INTDIR)\md_crypt.obj" \

+	"$(INTDIR)\md_curl.obj" \

+	"$(INTDIR)\md_event.obj" \

+	"$(INTDIR)\md_http.obj" \

+	"$(INTDIR)\md_json.obj" \

+	"$(INTDIR)\md_jws.obj" \

+	"$(INTDIR)\md_log.obj" \

+	"$(INTDIR)\md_ocsp.obj" \

+	"$(INTDIR)\md_reg.obj" \

+	"$(INTDIR)\md_result.obj" \

+	"$(INTDIR)\md_status.obj" \

+	"$(INTDIR)\md_store.obj" \

+	"$(INTDIR)\md_store_fs.obj" \

+	"$(INTDIR)\md_tailscale.obj" \

+	"$(INTDIR)\md_time.obj" \

+	"$(INTDIR)\md_util.obj" \

+	"$(INTDIR)\md_acme.obj" \

+	"$(INTDIR)\md_acme_acct.obj" \

+	"$(INTDIR)\md_acme_authz.obj" \

+	"$(INTDIR)\md_acme_drive.obj" \

+	"$(INTDIR)\md_acme_order.obj" \

+	"$(INTDIR)\md_acmev2_drive.obj" \

+	"$(INTDIR)\mod_md.res" \

+	"..\..\srclib\apr\Debug\libapr-1.lib" \

+	"..\..\srclib\apr-util\Debug\libaprutil-1.lib" \

+	"..\..\Debug\libhttpd.lib"

+

+"$(OUTDIR)\mod_md.so" : "$(OUTDIR)" $(DEF_FILE) $(LINK32_OBJS)

+    $(LINK32) @<<

+  $(LINK32_FLAGS) $(LINK32_OBJS)

+<<

+

+TargetPath=.\Debug\mod_md.so

+SOURCE="$(InputPath)"

+PostBuild_Desc=Embed .manifest

+DS_POSTBUILD_DEP=$(INTDIR)\postbld.dep

+

+ALL : $(DS_POSTBUILD_DEP)

+

+# Begin Custom Macros

+OutDir=.\Debug

+# End Custom Macros

+

+$(DS_POSTBUILD_DEP) : "libhttpd - Win32 Debug" "libaprutil - Win32 Debug" "libapr - Win32 Debug" "$(OUTDIR)\mod_md.so"

+   if exist .\Debug\mod_md.so.manifest mt.exe -manifest .\Debug\mod_md.so.manifest -outputresource:.\Debug\mod_md.so;2

+	echo Helper for Post-build step > "$(DS_POSTBUILD_DEP)"

+

+!ENDIF 

+

+

+!IF "$(NO_EXTERNAL_DEPS)" != "1"

+!IF EXISTS("mod_md.dep")

+!INCLUDE "mod_md.dep"

+!ELSE 

+!MESSAGE Warning: cannot find "mod_md.dep"

+!ENDIF 

+!ENDIF 

+

+

+!IF "$(CFG)" == "mod_md - Win32 Release" || "$(CFG)" == "mod_md - Win32 Debug"

+

+!IF  "$(CFG)" == "mod_md - Win32 Release"

+

+"libapr - Win32 Release" : 

+   cd "..\..\srclib\apr"

+   $(MAKE) /$(MAKEFLAGS) /F ".\libapr.mak" CFG="libapr - Win32 Release" 

+   cd "..\..\modules\md"

+

+"libapr - Win32 ReleaseCLEAN" : 

+   cd "..\..\srclib\apr"

+   $(MAKE) /$(MAKEFLAGS) /F ".\libapr.mak" CFG="libapr - Win32 Release" RECURSE=1 CLEAN 

+   cd "..\..\modules\md"

+

+!ELSEIF  "$(CFG)" == "mod_md - Win32 Debug"

+

+"libapr - Win32 Debug" : 

+   cd "..\..\srclib\apr"

+   $(MAKE) /$(MAKEFLAGS) /F ".\libapr.mak" CFG="libapr - Win32 Debug" 

+   cd "..\..\modules\md"

+

+"libapr - Win32 DebugCLEAN" : 

+   cd "..\..\srclib\apr"

+   $(MAKE) /$(MAKEFLAGS) /F ".\libapr.mak" CFG="libapr - Win32 Debug" RECURSE=1 CLEAN 

+   cd "..\..\modules\md"

+

+!ENDIF 

+

+!IF  "$(CFG)" == "mod_md - Win32 Release"

+

+"libaprutil - Win32 Release" : 

+   cd "..\..\srclib\apr-util"

+   $(MAKE) /$(MAKEFLAGS) /F ".\libaprutil.mak" CFG="libaprutil - Win32 Release" 

+   cd "..\..\modules\md"

+

+"libaprutil - Win32 ReleaseCLEAN" : 

+   cd "..\..\srclib\apr-util"

+   $(MAKE) /$(MAKEFLAGS) /F ".\libaprutil.mak" CFG="libaprutil - Win32 Release" RECURSE=1 CLEAN 

+   cd "..\..\modules\md"

+

+!ELSEIF  "$(CFG)" == "mod_md - Win32 Debug"

+

+"libaprutil - Win32 Debug" : 

+   cd "..\..\srclib\apr-util"

+   $(MAKE) /$(MAKEFLAGS) /F ".\libaprutil.mak" CFG="libaprutil - Win32 Debug" 

+   cd "..\..\modules\md"

+

+"libaprutil - Win32 DebugCLEAN" : 

+   cd "..\..\srclib\apr-util"

+   $(MAKE) /$(MAKEFLAGS) /F ".\libaprutil.mak" CFG="libaprutil - Win32 Debug" RECURSE=1 CLEAN 

+   cd "..\..\modules\md"

+

+!ENDIF 

+

+!IF  "$(CFG)" == "mod_md - Win32 Release"

+

+"libhttpd - Win32 Release" : 

+   cd "..\.."

+   $(MAKE) /$(MAKEFLAGS) /F ".\libhttpd.mak" CFG="libhttpd - Win32 Release" 

+   cd ".\modules\md"

+

+"libhttpd - Win32 ReleaseCLEAN" : 

+   cd "..\.."

+   $(MAKE) /$(MAKEFLAGS) /F ".\libhttpd.mak" CFG="libhttpd - Win32 Release" RECURSE=1 CLEAN 

+   cd ".\modules\md"

+

+!ELSEIF  "$(CFG)" == "mod_md - Win32 Debug"

+

+"libhttpd - Win32 Debug" : 

+   cd "..\.."

+   $(MAKE) /$(MAKEFLAGS) /F ".\libhttpd.mak" CFG="libhttpd - Win32 Debug" 

+   cd ".\modules\md"

+

+"libhttpd - Win32 DebugCLEAN" : 

+   cd "..\.."

+   $(MAKE) /$(MAKEFLAGS) /F ".\libhttpd.mak" CFG="libhttpd - Win32 Debug" RECURSE=1 CLEAN 

+   cd ".\modules\md"

+

+!ENDIF 

+

+SOURCE=..\..\build\win32\httpd.rc

+

+!IF  "$(CFG)" == "mod_md - Win32 Release"

+

+

+"$(INTDIR)\mod_md.res" : $(SOURCE) "$(INTDIR)"

+	$(RSC) /l 0x409 /fo"$(INTDIR)\mod_md.res" /i "../../include" /i "../../srclib/apr/include" /i "../../build\win32" /d "NDEBUG" /d BIN_NAME="mod_md.so" /d LONG_NAME="md_module for Apache" $(SOURCE)

+

+

+!ELSEIF  "$(CFG)" == "mod_md - Win32 Debug"

+

+

+"$(INTDIR)\mod_md.res" : $(SOURCE) "$(INTDIR)"

+	$(RSC) /l 0x409 /fo"$(INTDIR)\mod_md.res" /i "../../include" /i "../../srclib/apr/include" /i "../../build\win32" /d "_DEBUG" /d BIN_NAME="mod_md.so" /d LONG_NAME="md_module for Apache" $(SOURCE)

+

+

+!ENDIF 

+

+SOURCE=./md_acme.c

+

+"$(INTDIR)\md_acme.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_acme_acct.c

+

+"$(INTDIR)\md_acme_acct.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_acme_authz.c

+

+"$(INTDIR)\md_acme_authz.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_acme_drive.c

+

+"$(INTDIR)\md_acme_drive.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_acme_order.c

+

+"$(INTDIR)\md_acme_order.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_acmev2_drive.c

+

+"$(INTDIR)\md_acmev2_drive.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_core.c

+

+"$(INTDIR)\md_core.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_crypt.c

+

+"$(INTDIR)\md_crypt.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_curl.c

+

+"$(INTDIR)\md_curl.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_event.c

+

+"$(INTDIR)\md_event.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_http.c

+

+"$(INTDIR)\md_http.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_json.c

+

+"$(INTDIR)\md_json.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_jws.c

+

+"$(INTDIR)\md_jws.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_log.c

+

+"$(INTDIR)\md_log.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_ocsp.c

+

+"$(INTDIR)\md_ocsp.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_reg.c

+

+"$(INTDIR)\md_reg.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_result.c

+

+"$(INTDIR)\md_result.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_status.c

+

+"$(INTDIR)\md_status.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_store.c

+

+"$(INTDIR)\md_store.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_store_fs.c

+

+"$(INTDIR)\md_store_fs.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_tailscale.c

+

+"$(INTDIR)\md_tailscale.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_time.c

+

+"$(INTDIR)\md_time.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./md_util.c

+

+"$(INTDIR)\md_util.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./mod_md.c

+

+"$(INTDIR)\mod_md.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./mod_md_config.c

+

+"$(INTDIR)\mod_md_config.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./mod_md_drive.c

+

+"$(INTDIR)\mod_md_drive.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./mod_md_ocsp.c

+

+"$(INTDIR)\mod_md_ocsp.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./mod_md_os.c

+

+"$(INTDIR)\mod_md_os.obj" : $(SOURCE) "$(INTDIR)"

+

+

+SOURCE=./mod_md_status.c

+

+"$(INTDIR)\mod_md_status.obj" : $(SOURCE) "$(INTDIR)"

+

+

+!ENDIF 

+

diff --git a/modules/md/mod_md_config.c b/modules/md/mod_md_config.c
new file mode 100644
index 0000000..e117b16
--- /dev/null
+++ b/modules/md/mod_md_config.c
@@ -0,0 +1,1388 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+
+#include <httpd.h>
+#include <http_core.h>
+#include <http_config.h>
+#include <http_log.h>
+#include <http_vhost.h>
+
+#include "md.h"
+#include "md_acme.h"
+#include "md_crypt.h"
+#include "md_log.h"
+#include "md_json.h"
+#include "md_util.h"
+#include "mod_md_private.h"
+#include "mod_md_config.h"
+
+#define MD_CMD_MD_SECTION     "<MDomainSet"
+#define MD_CMD_MD2_SECTION    "<MDomain"
+
+#define DEF_VAL     (-1)
+
+#ifndef MD_DEFAULT_BASE_DIR
+#define MD_DEFAULT_BASE_DIR "md"
+#endif
+
+static md_timeslice_t def_ocsp_keep_window = {
+    0,
+    MD_TIME_OCSP_KEEP_NORM,
+};
+
+static md_timeslice_t def_ocsp_renew_window = {
+    MD_TIME_LIFE_NORM,
+    MD_TIME_RENEW_WINDOW_DEF,
+};
+
+/* Default settings for the global conf */
+static md_mod_conf_t defmc = {
+    NULL,                      /* list of mds */
+#if AP_MODULE_MAGIC_AT_LEAST(20180906, 2)
+    NULL,                      /* base dirm by default state-dir-relative */
+#else
+    MD_DEFAULT_BASE_DIR,
+#endif
+    NULL,                      /* proxy url for outgoing http */
+    NULL,                      /* md_reg_t */
+    NULL,                      /* md_ocsp_reg_t */
+    80,                        /* local http: port */
+    443,                       /* local https: port */
+    -1,                        /* can http: */
+    -1,                        /* can https: */
+    0,                         /* manage base server */
+    MD_HSTS_MAX_AGE_DEFAULT,   /* hsts max-age */
+    NULL,                      /* hsts headers */
+    NULL,                      /* unused names */
+    NULL,                      /* init errors hash */
+    NULL,                      /* notify cmd */
+    NULL,                      /* message cmd */
+    NULL,                      /* env table */
+    0,                         /* dry_run flag */
+    1,                         /* server_status_enabled */
+    1,                         /* certificate_status_enabled */
+    &def_ocsp_keep_window,     /* default time to keep ocsp responses */
+    &def_ocsp_renew_window,    /* default time to renew ocsp responses */
+    "crt.sh",                  /* default cert checker site name */
+    "https://crt.sh?q=",       /* default cert checker site url */
+    NULL,                      /* CA cert file to use */
+    apr_time_from_sec(5),      /* minimum delay for retries */
+    13,                        /* retry_failover after 14 errors, with 5s delay ~ half a day */
+    0,                         /* store locks, disabled by default */
+    apr_time_from_sec(5),      /* max time to wait to obaint a store lock */
+};
+
+static md_timeslice_t def_renew_window = {
+    MD_TIME_LIFE_NORM,
+    MD_TIME_RENEW_WINDOW_DEF,
+};
+static md_timeslice_t def_warn_window = {
+    MD_TIME_LIFE_NORM,
+    MD_TIME_WARN_WINDOW_DEF,
+};
+
+/* Default server specific setting */
+static md_srv_conf_t defconf = {
+    "default",                 /* name */
+    NULL,                      /* server_rec */
+    &defmc,                    /* mc */
+    1,                         /* transitive */
+    MD_REQUIRE_OFF,            /* require https */
+    MD_RENEW_AUTO,             /* renew mode */
+    0,                         /* must staple */
+    NULL,                      /* pkey spec */
+    &def_renew_window,         /* renew window */
+    &def_warn_window,          /* warn window */
+    NULL,                      /* ca urls */
+    NULL,                      /* ca contact (email) */
+    MD_PROTO_ACME,             /* ca protocol */
+    NULL,                      /* ca agreemnent */
+    NULL,                      /* ca challenges array */
+    NULL,                      /* ca eab kid */
+    NULL,                      /* ca eab hmac */
+    0,                         /* stapling */
+    1,                         /* staple others */
+    NULL,                      /* dns01_cmd */
+    NULL,                      /* currently defined md */
+    NULL,                      /* assigned md, post config */
+    0,                         /* is_ssl, set during mod_ssl post_config */
+};
+
+static md_mod_conf_t *mod_md_config;
+
+static apr_status_t cleanup_mod_config(void *dummy)
+{
+    (void)dummy;
+    mod_md_config = NULL;
+    return APR_SUCCESS;
+}
+
+static md_mod_conf_t *md_mod_conf_get(apr_pool_t *pool, int create)
+{
+    if (mod_md_config) {
+        return mod_md_config; /* reused for lifetime of the pool */
+    }
+
+    if (create) {
+        mod_md_config = apr_pcalloc(pool, sizeof(*mod_md_config));
+        memcpy(mod_md_config, &defmc, sizeof(*mod_md_config));
+        mod_md_config->mds = apr_array_make(pool, 5, sizeof(const md_t *));
+        mod_md_config->unused_names = apr_array_make(pool, 5, sizeof(const md_t *));
+        mod_md_config->env = apr_table_make(pool, 10);
+        mod_md_config->init_errors = apr_hash_make(pool);
+         
+        apr_pool_cleanup_register(pool, NULL, cleanup_mod_config, apr_pool_cleanup_null);
+    }
+    
+    return mod_md_config;
+}
+
+#define CONF_S_NAME(s)  (s && s->server_hostname? s->server_hostname : "default")
+
+static void srv_conf_props_clear(md_srv_conf_t *sc)
+{
+    sc->transitive = DEF_VAL;
+    sc->require_https = MD_REQUIRE_UNSET;
+    sc->renew_mode = DEF_VAL;
+    sc->must_staple = DEF_VAL;
+    sc->pks = NULL;
+    sc->renew_window = NULL;
+    sc->warn_window = NULL;
+    sc->ca_urls = NULL;
+    sc->ca_contact = NULL;
+    sc->ca_proto = NULL;
+    sc->ca_agreement = NULL;
+    sc->ca_challenges = NULL;
+    sc->ca_eab_kid = NULL;
+    sc->ca_eab_hmac = NULL;
+    sc->stapling = DEF_VAL;
+    sc->staple_others = DEF_VAL;
+    sc->dns01_cmd = NULL;
+}
+
+static void srv_conf_props_copy(md_srv_conf_t *to, const md_srv_conf_t *from)
+{
+    to->transitive = from->transitive;
+    to->require_https = from->require_https;
+    to->renew_mode = from->renew_mode;
+    to->must_staple = from->must_staple;
+    to->pks = from->pks;
+    to->warn_window = from->warn_window;
+    to->renew_window = from->renew_window;
+    to->ca_urls = from->ca_urls;
+    to->ca_contact = from->ca_contact;
+    to->ca_proto = from->ca_proto;
+    to->ca_agreement = from->ca_agreement;
+    to->ca_challenges = from->ca_challenges;
+    to->ca_eab_kid = from->ca_eab_kid;
+    to->ca_eab_hmac = from->ca_eab_hmac;
+    to->stapling = from->stapling;
+    to->staple_others = from->staple_others;
+    to->dns01_cmd = from->dns01_cmd;
+}
+
+static void srv_conf_props_apply(md_t *md, const md_srv_conf_t *from, apr_pool_t *p)
+{
+    if (from->require_https != MD_REQUIRE_UNSET) md->require_https = from->require_https;
+    if (from->transitive != DEF_VAL) md->transitive = from->transitive;
+    if (from->renew_mode != DEF_VAL) md->renew_mode = from->renew_mode;
+    if (from->must_staple != DEF_VAL) md->must_staple = from->must_staple;
+    if (from->pks) md->pks = md_pkeys_spec_clone(p, from->pks);
+    if (from->renew_window) md->renew_window = from->renew_window;
+    if (from->warn_window) md->warn_window = from->warn_window;
+    if (from->ca_urls) md->ca_urls = apr_array_copy(p, from->ca_urls);
+    if (from->ca_proto) md->ca_proto = from->ca_proto;
+    if (from->ca_agreement) md->ca_agreement = from->ca_agreement;
+    if (from->ca_contact) {
+        apr_array_clear(md->contacts);
+        APR_ARRAY_PUSH(md->contacts, const char *) =
+            md_util_schemify(p, from->ca_contact, "mailto");
+    }
+    if (from->ca_challenges) md->ca_challenges = apr_array_copy(p, from->ca_challenges);
+    if (from->ca_eab_kid) md->ca_eab_kid = from->ca_eab_kid;
+    if (from->ca_eab_hmac) md->ca_eab_hmac = from->ca_eab_hmac;
+    if (from->stapling != DEF_VAL) md->stapling = from->stapling;
+    if (from->dns01_cmd) md->dns01_cmd = from->dns01_cmd;
+}
+
+void *md_config_create_svr(apr_pool_t *pool, server_rec *s)
+{
+    md_srv_conf_t *conf = (md_srv_conf_t *)apr_pcalloc(pool, sizeof(md_srv_conf_t));
+
+    conf->name = apr_pstrcat(pool, "srv[", CONF_S_NAME(s), "]", NULL);
+    conf->s = s;
+    conf->mc = md_mod_conf_get(pool, 1);
+
+    srv_conf_props_clear(conf);
+    
+    return conf;
+}
+
+static void *md_config_merge(apr_pool_t *pool, void *basev, void *addv)
+{
+    md_srv_conf_t *base = (md_srv_conf_t *)basev;
+    md_srv_conf_t *add = (md_srv_conf_t *)addv;
+    md_srv_conf_t *nsc;
+    char *name = apr_pstrcat(pool, "[", CONF_S_NAME(add->s), ", ", CONF_S_NAME(base->s), "]", NULL);
+    
+    nsc = (md_srv_conf_t *)apr_pcalloc(pool, sizeof(md_srv_conf_t));
+    nsc->name = name;
+    nsc->mc = add->mc? add->mc : base->mc;
+
+    nsc->transitive = (add->transitive != DEF_VAL)? add->transitive : base->transitive;
+    nsc->require_https = (add->require_https != MD_REQUIRE_UNSET)? add->require_https : base->require_https;
+    nsc->renew_mode = (add->renew_mode != DEF_VAL)? add->renew_mode : base->renew_mode;
+    nsc->must_staple = (add->must_staple != DEF_VAL)? add->must_staple : base->must_staple;
+    nsc->pks = (!md_pkeys_spec_is_empty(add->pks))? add->pks : base->pks;
+    nsc->renew_window = add->renew_window? add->renew_window : base->renew_window;
+    nsc->warn_window = add->warn_window? add->warn_window : base->warn_window;
+
+    nsc->ca_urls = add->ca_urls? apr_array_copy(pool, add->ca_urls)
+                    : (base->ca_urls? apr_array_copy(pool, base->ca_urls) : NULL);
+    nsc->ca_contact = add->ca_contact? add->ca_contact : base->ca_contact;
+    nsc->ca_proto = add->ca_proto? add->ca_proto : base->ca_proto;
+    nsc->ca_agreement = add->ca_agreement? add->ca_agreement : base->ca_agreement;
+    nsc->ca_challenges = (add->ca_challenges? apr_array_copy(pool, add->ca_challenges) 
+                    : (base->ca_challenges? apr_array_copy(pool, base->ca_challenges) : NULL));
+    nsc->ca_eab_kid = add->ca_eab_kid? add->ca_eab_kid : base->ca_eab_kid;
+    nsc->ca_eab_hmac = add->ca_eab_hmac? add->ca_eab_hmac : base->ca_eab_hmac;
+    nsc->stapling = (add->stapling != DEF_VAL)? add->stapling : base->stapling;
+    nsc->staple_others = (add->staple_others != DEF_VAL)? add->staple_others : base->staple_others;
+    nsc->dns01_cmd = (add->dns01_cmd)? add->dns01_cmd : base->dns01_cmd;
+    nsc->current = NULL;
+    
+    return nsc;
+}
+
+void *md_config_merge_svr(apr_pool_t *pool, void *basev, void *addv)
+{
+    return md_config_merge(pool, basev, addv);
+}
+
+static int inside_section(cmd_parms *cmd, const char *section) {
+    ap_directive_t *d;
+    for (d = cmd->directive->parent; d; d = d->parent) {
+       if (!ap_cstr_casecmp(d->directive, section)) {
+           return 1;
+       }
+    }
+    return 0; 
+}
+
+static int inside_md_section(cmd_parms *cmd) {
+    return (inside_section(cmd, MD_CMD_MD_SECTION) || inside_section(cmd, MD_CMD_MD2_SECTION));
+}
+
+static const char *md_section_check(cmd_parms *cmd) {
+    if (!inside_md_section(cmd)) {
+        return apr_pstrcat(cmd->pool, cmd->cmd->name, " is only valid inside a '",  
+                           MD_CMD_MD_SECTION, "' context, not here", NULL);
+    }
+    return NULL;
+}
+
+#define MD_LOC_GLOBAL (0x01)
+#define MD_LOC_MD     (0x02)
+#define MD_LOC_ELSE   (0x04)
+#define MD_LOC_ALL    (0x07)
+#define MD_LOC_NOT_MD (0x102)
+
+static const char *md_conf_check_location(cmd_parms *cmd, int flags)
+{
+    if (MD_LOC_GLOBAL == flags) {
+        return ap_check_cmd_context(cmd, GLOBAL_ONLY);
+    }
+    if (MD_LOC_NOT_MD == flags && inside_md_section(cmd)) {
+        return apr_pstrcat(cmd->pool, cmd->cmd->name, " is not allowed inside an '",  
+                           MD_CMD_MD_SECTION, "' context", NULL);
+    }
+    if (MD_LOC_MD == flags) {
+        return md_section_check(cmd);
+    }
+    else if ((MD_LOC_MD & flags) && inside_md_section(cmd)) {
+        return NULL;
+    } 
+    return ap_check_cmd_context(cmd, NOT_IN_DIRECTORY|NOT_IN_LOCATION);
+}
+
+static const char *set_on_off(int *pvalue, const char *s, apr_pool_t *p)
+{
+    if (!apr_strnatcasecmp("off", s)) {
+        *pvalue = 0;
+    }
+    else if (!apr_strnatcasecmp("on", s)) {
+        *pvalue = 1;
+    }
+    else {
+        return apr_pstrcat(p, "unknown '", s, 
+                           "', supported parameter values are 'on' and 'off'", NULL);
+    }
+    return NULL;
+}
+
+
+static void add_domain_name(apr_array_header_t *domains, const char *name, apr_pool_t *p)
+{
+    if (md_array_str_index(domains, name, 0, 0) < 0) {
+        APR_ARRAY_PUSH(domains, char *) = md_util_str_tolower(apr_pstrdup(p, name));
+    }
+}
+
+static const char *set_transitive(int *ptransitive, const char *value)
+{
+    if (!apr_strnatcasecmp("auto", value)) {
+        *ptransitive = 1;
+        return NULL;
+    }
+    else if (!apr_strnatcasecmp("manual", value)) {
+        *ptransitive = 0;
+        return NULL;
+    }
+    return "unknown value, use \"auto|manual\"";
+}
+
+static const char *md_config_sec_start(cmd_parms *cmd, void *mconfig, const char *arg)
+{
+    md_srv_conf_t *sc;
+    md_srv_conf_t save;
+    const char *endp;
+    const char *err, *name;
+    apr_array_header_t *domains;
+    md_t *md;
+    int transitive = -1;
+    
+    (void)mconfig;
+    if ((err = md_conf_check_location(cmd, MD_LOC_NOT_MD))) {
+        return err;
+    }
+        
+    sc = md_config_get(cmd->server);
+    endp = ap_strrchr_c(arg, '>');
+    if (endp == NULL) {
+        return  MD_CMD_MD_SECTION "> directive missing closing '>'";
+    }
+
+    arg = apr_pstrndup(cmd->pool, arg, (apr_size_t)(endp-arg));
+    if (!arg || !*arg) {
+        return MD_CMD_MD_SECTION " > section must specify a unique domain name";
+    }
+
+    name = ap_getword_conf(cmd->pool, &arg);
+    domains = apr_array_make(cmd->pool, 5, sizeof(const char *));
+    add_domain_name(domains, name, cmd->pool);
+    while (*arg != '\0') {
+        name = ap_getword_conf(cmd->pool, &arg);
+        if (NULL != set_transitive(&transitive, name)) {
+            add_domain_name(domains, name, cmd->pool);
+        }
+    }
+
+    if (domains->nelts == 0) {
+        return "needs at least one domain name";
+    }
+    
+    md = md_create(cmd->pool, domains);
+    if (transitive >= 0) {
+        md->transitive = transitive;
+    }
+    
+    /* Save the current settings in this srv_conf and apply+restore at the
+     * end of this section */
+    memcpy(&save, sc, sizeof(save));
+    srv_conf_props_clear(sc);
+    sc->current = md;
+    
+    if (NULL == (err = ap_walk_config(cmd->directive->first_child, cmd, cmd->context))) {
+        srv_conf_props_apply(md, sc, cmd->pool);
+        APR_ARRAY_PUSH(sc->mc->mds, const md_t *) = md;
+    }
+    
+    sc->current = NULL;
+    srv_conf_props_copy(sc, &save);
+    
+    return err;
+}
+
+static const char *md_config_sec_add_members(cmd_parms *cmd, void *dc, 
+                                             int argc, char *const argv[])
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+    int i;
+    
+    (void)dc;
+    if (NULL != (err = md_section_check(cmd))) {
+        if (argc == 1) {
+            /* only these values are allowed outside a section */
+            return set_transitive(&sc->transitive, argv[0]);
+        }
+        return err;
+    }
+    
+    assert(sc->current);
+    for (i = 0; i < argc; ++i) {
+        if (NULL != set_transitive(&sc->transitive, argv[i])) {
+            add_domain_name(sc->current->domains, argv[i], cmd->pool);
+        }
+    }
+    return NULL;
+}
+
+static const char *md_config_set_names(cmd_parms *cmd, void *dc, 
+                                       int argc, char *const argv[])
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    apr_array_header_t *domains = apr_array_make(cmd->pool, 5, sizeof(const char *));
+    const char *err;
+    md_t *md;
+    int i, transitive = -1;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_NOT_MD))) {
+        return err;
+    }
+
+    for (i = 0; i < argc; ++i) {
+        if (NULL != set_transitive(&transitive, argv[i])) {
+            add_domain_name(domains, argv[i], cmd->pool);
+        }
+    }
+    
+    if (domains->nelts == 0) {
+        return "needs at least one domain name";
+    }
+    md = md_create(cmd->pool, domains);
+
+    if (transitive >= 0) {
+        md->transitive = transitive;
+    }
+    
+    if (cmd->config_file) {
+        md->defn_name = cmd->config_file->name;
+        md->defn_line_number = cmd->config_file->line_number;
+    }
+
+    APR_ARRAY_PUSH(sc->mc->mds, md_t *) = md;
+
+    return NULL;
+}
+
+static const char *md_config_set_ca(cmd_parms *cmd, void *dc,
+                                    int argc, char *const argv[])
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err, *url;
+    int i;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    if (!sc->ca_urls) {
+        sc->ca_urls = apr_array_make(cmd->pool, 3, sizeof(const char *));
+    }
+    else {
+        apr_array_clear(sc->ca_urls);
+    }
+    for (i = 0; i < argc; ++i) {
+        if (APR_SUCCESS != md_get_ca_url_from_name(&url, cmd->pool, argv[i])) {
+            return url;
+        }
+        APR_ARRAY_PUSH(sc->ca_urls, const char *) = url;
+    }
+    return NULL;
+}
+
+static const char *md_config_set_contact(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    sc->ca_contact = value;
+    return NULL;
+}
+
+static const char *md_config_set_ca_proto(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    config->ca_proto = value;
+    return NULL;
+}
+
+static const char *md_config_set_agreement(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    config->ca_agreement = value;
+    return NULL;
+}
+
+static const char *md_config_set_renew_mode(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err;
+    md_renew_mode_t renew_mode;
+
+    (void)dc;
+    if (!apr_strnatcasecmp("auto", value) || !apr_strnatcasecmp("automatic", value)) {
+        renew_mode = MD_RENEW_AUTO;
+    }
+    else if (!apr_strnatcasecmp("always", value)) {
+        renew_mode = MD_RENEW_ALWAYS;
+    }
+    else if (!apr_strnatcasecmp("manual", value) || !apr_strnatcasecmp("stick", value)) {
+        renew_mode = MD_RENEW_MANUAL;
+    }
+    else {
+        return apr_pstrcat(cmd->pool, "unknown MDDriveMode ", value, NULL);
+    }
+    
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    config->renew_mode = renew_mode;
+    return NULL;
+}
+
+static const char *md_config_set_must_staple(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    return set_on_off(&config->must_staple, value, cmd->pool);
+}
+
+static const char *md_config_set_stapling(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    return set_on_off(&config->stapling, value, cmd->pool);
+}
+
+static const char *md_config_set_staple_others(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    return set_on_off(&config->staple_others, value, cmd->pool);
+}
+
+static const char *md_config_set_base_server(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err = md_conf_check_location(cmd, MD_LOC_NOT_MD);
+
+    (void)dc;
+    if (err) return err;
+    return set_on_off(&config->mc->manage_base_server, value, cmd->pool);
+}
+
+static const char *md_config_set_min_delay(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err = md_conf_check_location(cmd, MD_LOC_NOT_MD);
+    apr_time_t delay;
+
+    (void)dc;
+    if (err) return err;
+    if (md_duration_parse(&delay, value, "s") != APR_SUCCESS) {
+        return "unrecognized duration format";
+    }
+    config->mc->min_delay = delay;
+    return NULL;
+}
+
+static const char *md_config_set_retry_failover(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err = md_conf_check_location(cmd, MD_LOC_NOT_MD);
+    int retry_failover;
+
+    (void)dc;
+    if (err) return err;
+    retry_failover = atoi(value);
+    if (retry_failover <= 0) {
+        return "invalid argument, must be a number > 0";
+    }
+    config->mc->retry_failover = retry_failover;
+    return NULL;
+}
+
+static const char *md_config_set_store_locks(cmd_parms *cmd, void *dc, const char *s)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err = md_conf_check_location(cmd, MD_LOC_NOT_MD);
+    int use_store_locks;
+    apr_time_t wait_time = 0;
+
+    (void)dc;
+    if (err) {
+        return err;
+    }
+    else if (!apr_strnatcasecmp("off", s)) {
+        use_store_locks = 0;
+    }
+    else if (!apr_strnatcasecmp("on", s)) {
+        use_store_locks = 1;
+    }
+    else {
+        if (md_duration_parse(&wait_time, s, "s") != APR_SUCCESS) {
+            return "neither 'on', 'off' or a duration specified";
+        }
+        use_store_locks = (wait_time != 0);
+    }
+    config->mc->use_store_locks = use_store_locks;
+    if (wait_time) {
+        config->mc->lock_wait_timeout = wait_time;
+    }
+    return NULL;
+}
+
+static const char *md_config_set_require_https(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err;
+
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    (void)dc;
+    if (!apr_strnatcasecmp("off", value)) {
+        config->require_https = MD_REQUIRE_OFF;
+    }
+    else if (!apr_strnatcasecmp(MD_KEY_TEMPORARY, value)) {
+        config->require_https = MD_REQUIRE_TEMPORARY;
+    }
+    else if (!apr_strnatcasecmp(MD_KEY_PERMANENT, value)) {
+        config->require_https = MD_REQUIRE_PERMANENT;
+    }
+    else {
+        return apr_pstrcat(cmd->pool, "unknown '", value, 
+                           "', supported parameter values are 'temporary' and 'permanent'", NULL);
+    }
+    return NULL;
+}
+
+static const char *md_config_set_renew_window(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err;
+    
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    err = md_timeslice_parse(&config->renew_window, cmd->pool, value, MD_TIME_LIFE_NORM);
+    if (!err && config->renew_window->norm 
+        && (config->renew_window->len >= config->renew_window->norm)) {
+        err = "a length of 100% or more is not allowed.";
+    }
+    if (err) return apr_psprintf(cmd->pool, "MDRenewWindow %s", err);
+    return NULL;
+}
+
+static const char *md_config_set_warn_window(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err;
+    
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    err = md_timeslice_parse(&config->warn_window, cmd->pool, value, MD_TIME_LIFE_NORM);
+    if (!err && config->warn_window->norm 
+        && (config->warn_window->len >= config->warn_window->norm)) {
+        err = "a length of 100% or more is not allowed.";
+    }
+    if (err) return apr_psprintf(cmd->pool, "MDWarnWindow %s", err);
+    return NULL;
+}
+
+static const char *md_config_set_proxy(cmd_parms *cmd, void *arg, const char *value)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    if ((err = md_conf_check_location(cmd, MD_LOC_NOT_MD))) {
+        return err;
+    }
+    md_util_abs_http_uri_check(cmd->pool, value, &err);
+    if (err) {
+        return err;
+    }
+    sc->mc->proxy_url = value;
+    (void)arg;
+    return NULL;
+}
+
+static const char *md_config_set_store_dir(cmd_parms *cmd, void *arg, const char *value)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    if ((err = md_conf_check_location(cmd, MD_LOC_NOT_MD))) {
+        return err;
+    }
+    sc->mc->base_dir = value;
+    (void)arg;
+    return NULL;
+}
+
+static const char *set_port_map(md_mod_conf_t *mc, const char *value)
+{
+    int net_port, local_port;
+    const char *endp;
+
+    if (!strncmp("http:", value, sizeof("http:") - 1)) {
+        net_port = 80; endp = value + sizeof("http") - 1; 
+    }
+    else if (!strncmp("https:", value, sizeof("https:") - 1)) {
+        net_port = 443; endp = value + sizeof("https") - 1; 
+    }
+    else {
+        net_port = (int)apr_strtoi64(value, (char**)&endp, 10);
+        if (errno) {
+            return "unable to parse first port number";
+        }
+    }
+    if (!endp || *endp != ':') {
+        return "no ':' after first port number";
+    }
+    ++endp;
+    if (*endp == '-') {
+        local_port = 0;
+    }
+    else {
+        local_port = (int)apr_strtoi64(endp, (char**)&endp, 10);
+        if (errno) {
+            return "unable to parse second port number";
+        }
+        if (local_port <= 0 || local_port > 65535) {
+            return "invalid number for port map, must be in ]0,65535]";
+        }
+    }
+    switch (net_port) {
+        case 80:
+            mc->local_80 = local_port;
+            break;
+        case 443:
+            mc->local_443 = local_port;
+            break;
+        default:
+            return "mapped port number must be 80 or 443";
+    }
+    return NULL;
+}
+
+static const char *md_config_set_port_map(cmd_parms *cmd, void *arg, 
+                                          const char *v1, const char *v2)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    (void)arg;
+    if (!(err = md_conf_check_location(cmd, MD_LOC_NOT_MD))) {
+        err = set_port_map(sc->mc, v1);
+    }
+    if (!err && v2) {
+        err = set_port_map(sc->mc, v2);
+    }
+    return err;
+}
+
+static const char *md_config_set_cha_tyes(cmd_parms *cmd, void *dc, 
+                                          int argc, char *const argv[])
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    apr_array_header_t **pcha, *ca_challenges;
+    const char *err;
+    int i;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    pcha = &config->ca_challenges; 
+    
+    ca_challenges = *pcha;
+    if (ca_challenges) {
+        apr_array_clear(ca_challenges);
+    }
+    else {
+        *pcha = ca_challenges = apr_array_make(cmd->pool, 5, sizeof(const char *));
+    }
+    for (i = 0; i < argc; ++i) {
+        APR_ARRAY_PUSH(ca_challenges, const char *) = argv[i];
+    }
+    
+    return NULL;
+}
+
+static const char *md_config_set_pkeys(cmd_parms *cmd, void *dc, 
+                                       int argc, char *const argv[])
+{
+    md_srv_conf_t *config = md_config_get(cmd->server);
+    const char *err, *ptype;
+    apr_int64_t bits;
+    int i;
+    
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    if (argc <= 0) {
+        return "needs to specify the private key type";
+    }
+    
+    config->pks = md_pkeys_spec_make(cmd->pool);
+    for (i = 0; i < argc; ++i) {
+        ptype = argv[i];
+        if (!apr_strnatcasecmp("Default", ptype)) {
+            if (argc > 1) {
+                return "'Default' allows no other parameter";
+            }
+            md_pkeys_spec_add_default(config->pks);
+        }
+        else if (strlen(ptype) > 3
+            && (ptype[0] == 'R' || ptype[0] == 'r')
+            && (ptype[1] == 'S' || ptype[1] == 's')
+            && (ptype[2] == 'A' || ptype[2] == 'a')
+            && isdigit(ptype[3])) {
+            bits = (int)apr_atoi64(ptype+3);
+            if (bits < MD_PKEY_RSA_BITS_MIN) {
+                return apr_psprintf(cmd->pool,
+                                    "must be %d or higher in order to be considered safe.",
+                                    MD_PKEY_RSA_BITS_MIN);
+            }
+            if (bits >= INT_MAX) {
+                return apr_psprintf(cmd->pool, "is too large for an RSA key length.");
+            }
+            if (md_pkeys_spec_contains_rsa(config->pks)) {
+                return "two keys of type 'RSA' are not possible.";
+            }
+            md_pkeys_spec_add_rsa(config->pks, (unsigned int)bits);
+        }
+        else if (!apr_strnatcasecmp("RSA", ptype)) {
+            if (i+1 >= argc || !isdigit(argv[i+1][0])) {
+                bits = MD_PKEY_RSA_BITS_DEF;
+            }
+            else {
+                ++i;
+                bits = (int)apr_atoi64(argv[i]);
+                if (bits < MD_PKEY_RSA_BITS_MIN) {
+                    return apr_psprintf(cmd->pool, 
+                                        "must be %d or higher in order to be considered safe.", 
+                                        MD_PKEY_RSA_BITS_MIN);
+                }
+                if (bits >= INT_MAX) {
+                    return apr_psprintf(cmd->pool, "is too large for an RSA key length.");
+                }
+            }
+            if (md_pkeys_spec_contains_rsa(config->pks)) {
+                return "two keys of type 'RSA' are not possible.";
+            }
+            md_pkeys_spec_add_rsa(config->pks, (unsigned int)bits);
+        }
+        else {
+            if (md_pkeys_spec_contains_ec(config->pks, argv[i])) {
+                return apr_psprintf(cmd->pool, "two keys of type '%s' are not possible.", argv[i]);
+            }
+            md_pkeys_spec_add_ec(config->pks, argv[i]);
+        }
+    }
+    return NULL;
+}
+
+static const char *md_config_set_notify_cmd(cmd_parms *cmd, void *mconfig, const char *arg)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    if ((err = md_conf_check_location(cmd, MD_LOC_NOT_MD))) {
+        return err;
+    }
+    sc->mc->notify_cmd = arg;
+    (void)mconfig;
+    return NULL;
+}
+
+static const char *md_config_set_msg_cmd(cmd_parms *cmd, void *mconfig, const char *arg)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    if ((err = md_conf_check_location(cmd, MD_LOC_NOT_MD))) {
+        return err;
+    }
+    sc->mc->message_cmd = arg;
+    (void)mconfig;
+    return NULL;
+}
+
+static const char *md_config_set_dns01_cmd(cmd_parms *cmd, void *mconfig, const char *arg)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+
+    if (inside_md_section(cmd)) {
+        sc->dns01_cmd = arg;
+    } else {
+        apr_table_set(sc->mc->env, MD_KEY_CMD_DNS01, arg);
+    }
+
+    (void)mconfig;
+    return NULL;
+}
+
+static const char *md_config_add_cert_file(cmd_parms *cmd, void *mconfig, const char *arg)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err, *fpath;
+    
+    (void)mconfig;
+    if ((err = md_conf_check_location(cmd, MD_LOC_MD))) return err;
+    assert(sc->current);
+    fpath = ap_server_root_relative(cmd->pool, arg);
+    if (!fpath) return apr_psprintf(cmd->pool, "certificate file not found: %s", arg);
+    if (!sc->current->cert_files) {
+        sc->current->cert_files = apr_array_make(cmd->pool, 3, sizeof(char*));
+    }
+    APR_ARRAY_PUSH(sc->current->cert_files, const char*) = fpath;
+    return NULL;
+}
+
+static const char *md_config_add_key_file(cmd_parms *cmd, void *mconfig, const char *arg)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err, *fpath;
+    
+    (void)mconfig;
+    if ((err = md_conf_check_location(cmd, MD_LOC_MD))) return err;
+    assert(sc->current);
+    fpath = ap_server_root_relative(cmd->pool, arg);
+    if (!fpath) return apr_psprintf(cmd->pool, "certificate key file not found: %s", arg);
+    if (!sc->current->pkey_files) {
+        sc->current->pkey_files = apr_array_make(cmd->pool, 3, sizeof(char*));
+    }
+    APR_ARRAY_PUSH(sc->current->pkey_files, const char*) = fpath;
+    return NULL;
+}
+
+static const char *md_config_set_server_status(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    return set_on_off(&sc->mc->server_status_enabled, value, cmd->pool);
+}
+
+static const char *md_config_set_certificate_status(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    return set_on_off(&sc->mc->certificate_status_enabled, value, cmd->pool);
+}
+
+static const char *md_config_set_ocsp_keep_window(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    err = md_timeslice_parse(&sc->mc->ocsp_keep_window, cmd->pool, value, MD_TIME_OCSP_KEEP_NORM);
+    if (err) return apr_psprintf(cmd->pool, "MDStaplingKeepResponse %s", err);
+    return NULL;
+}
+
+static const char *md_config_set_ocsp_renew_window(cmd_parms *cmd, void *dc, const char *value)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    err = md_timeslice_parse(&sc->mc->ocsp_renew_window, cmd->pool, value, MD_TIME_LIFE_NORM);
+    if (!err && sc->mc->ocsp_renew_window->norm 
+        && (sc->mc->ocsp_renew_window->len >= sc->mc->ocsp_renew_window->norm)) {
+        err = "with a length of 100% or more is not allowed.";
+    }
+    if (err) return apr_psprintf(cmd->pool, "MDStaplingRenewWindow %s", err);
+    return NULL;
+}
+
+static const char *md_config_set_cert_check(cmd_parms *cmd, void *dc, 
+                                            const char *name, const char *url)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    sc->mc->cert_check_name = name;
+    sc->mc->cert_check_url = url;
+    return NULL;
+}
+
+static const char *md_config_set_activation_delay(cmd_parms *cmd, void *mconfig, const char *arg)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+    apr_interval_time_t delay;
+
+    (void)mconfig;
+    if ((err = md_conf_check_location(cmd, MD_LOC_NOT_MD))) {
+        return err;
+    }
+    if (md_duration_parse(&delay, arg, "d") != APR_SUCCESS) {
+        return "unrecognized duration format";
+    }
+    apr_table_set(sc->mc->env, MD_KEY_ACTIVATION_DELAY, md_duration_format(cmd->pool, delay));
+    return NULL;
+}
+
+static const char *md_config_set_ca_certs(cmd_parms *cmd, void *dc, const char *path)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+
+    (void)dc;
+    sc->mc->ca_certs = path;
+    return NULL;
+}
+
+static const char *md_config_set_eab(cmd_parms *cmd, void *dc,
+                                     const char *keyid, const char *hmac)
+{
+    md_srv_conf_t *sc = md_config_get(cmd->server);
+    const char *err;
+
+    (void)dc;
+    if ((err = md_conf_check_location(cmd, MD_LOC_ALL))) {
+        return err;
+    }
+    if (!hmac) {
+        if (!apr_strnatcasecmp("None", keyid)) {
+            keyid = "none";
+        }
+        else {
+            /* a JSON file keeping keyid and hmac */
+            const char *fpath;
+            apr_status_t rv;
+            md_json_t *json;
+
+            /* If only dumping the config, don't verify the file */
+            if (ap_state_query(AP_SQ_RUN_MODE) == AP_SQ_RM_CONFIG_DUMP) {
+                goto leave;
+            }
+
+            fpath = ap_server_root_relative(cmd->pool, keyid);
+            if (!fpath) {
+                return apr_pstrcat(cmd->pool, cmd->cmd->name,
+                                   ": Invalid file path ", keyid, NULL);
+            }
+            if (!md_file_exists(fpath, cmd->pool)) {
+                return apr_pstrcat(cmd->pool, cmd->cmd->name,
+                                   ": file not found: ", fpath, NULL);
+            }
+
+            rv = md_json_readf(&json, cmd->pool, fpath);
+            if (APR_SUCCESS != rv) {
+                return apr_pstrcat(cmd->pool, cmd->cmd->name,
+                                   ": error reading JSON file ", fpath, NULL);
+            }
+            keyid = md_json_gets(json, MD_KEY_KID, NULL);
+            if (!keyid || !*keyid) {
+                return apr_pstrcat(cmd->pool, cmd->cmd->name,
+                                   ": JSON does not contain '", MD_KEY_KID,
+                                   "' element in file ", fpath, NULL);
+            }
+            hmac = md_json_gets(json, MD_KEY_HMAC, NULL);
+            if (!hmac || !*hmac) {
+                return apr_pstrcat(cmd->pool, cmd->cmd->name,
+                                   ": JSON does not contain '", MD_KEY_HMAC,
+                                   "' element in file ", fpath, NULL);
+            }
+        }
+    }
+leave:
+    sc->ca_eab_kid = keyid;
+    sc->ca_eab_hmac = hmac;
+    return NULL;
+}
+
+const command_rec md_cmds[] = {
+    AP_INIT_TAKE_ARGV("MDCertificateAuthority", md_config_set_ca, NULL, RSRC_CONF,
+                      "URL(s) or known name(s) of CA issuing the certificates"),
+    AP_INIT_TAKE1("MDCertificateAgreement", md_config_set_agreement, NULL, RSRC_CONF, 
+                  "either 'accepted' or the URL of CA Terms-of-Service agreement you accept"),
+    AP_INIT_TAKE_ARGV("MDCAChallenges", md_config_set_cha_tyes, NULL, RSRC_CONF, 
+                      "A list of challenge types to be used."),
+    AP_INIT_TAKE1("MDCertificateProtocol", md_config_set_ca_proto, NULL, RSRC_CONF, 
+                  "Protocol used to obtain/renew certificates"),
+    AP_INIT_TAKE1("MDContactEmail", md_config_set_contact, NULL, RSRC_CONF,
+                  "Email address used for account registration"),
+    AP_INIT_TAKE1("MDDriveMode", md_config_set_renew_mode, NULL, RSRC_CONF, 
+                  "deprecated, older name for MDRenewMode"),
+    AP_INIT_TAKE1("MDRenewMode", md_config_set_renew_mode, NULL, RSRC_CONF, 
+                  "Controls how renewal of Managed Domain certificates shall be handled."),
+    AP_INIT_TAKE_ARGV("MDomain", md_config_set_names, NULL, RSRC_CONF, 
+                      "A group of server names with one certificate"),
+    AP_INIT_RAW_ARGS(MD_CMD_MD_SECTION, md_config_sec_start, NULL, RSRC_CONF, 
+                     "Container for a managed domain with common settings and certificate."),
+    AP_INIT_RAW_ARGS(MD_CMD_MD2_SECTION, md_config_sec_start, NULL, RSRC_CONF, 
+                     "Short form for <MDomainSet> container."),
+    AP_INIT_TAKE_ARGV("MDMember", md_config_sec_add_members, NULL, RSRC_CONF, 
+                      "Define domain name(s) part of the Managed Domain. Use 'auto' or "
+                      "'manual' to enable/disable auto adding names from virtual hosts."),
+    AP_INIT_TAKE_ARGV("MDMembers", md_config_sec_add_members, NULL, RSRC_CONF, 
+                      "Define domain name(s) part of the Managed Domain. Use 'auto' or "
+                      "'manual' to enable/disable auto adding names from virtual hosts."),
+    AP_INIT_TAKE1("MDMustStaple", md_config_set_must_staple, NULL, RSRC_CONF, 
+                  "Enable/Disable the Must-Staple flag for new certificates."),
+    AP_INIT_TAKE12("MDPortMap", md_config_set_port_map, NULL, RSRC_CONF, 
+                  "Declare the mapped ports 80 and 443 on the local server. E.g. 80:8000 "
+                  "to indicate that the server port 8000 is reachable as port 80 from the "
+                  "internet. Use 80:- to indicate that port 80 is not reachable from "
+                  "the outside."),
+    AP_INIT_TAKE_ARGV("MDPrivateKeys", md_config_set_pkeys, NULL, RSRC_CONF, 
+                  "set the type and parameters for private key generation"),
+    AP_INIT_TAKE1("MDHttpProxy", md_config_set_proxy, NULL, RSRC_CONF, 
+                  "URL of a HTTP(S) proxy to use for outgoing connections"),
+    AP_INIT_TAKE1("MDStoreDir", md_config_set_store_dir, NULL, RSRC_CONF, 
+                  "the directory for file system storage of managed domain data."),
+    AP_INIT_TAKE1("MDRenewWindow", md_config_set_renew_window, NULL, RSRC_CONF, 
+                  "Time length for renewal before certificate expires (defaults to days)."),
+    AP_INIT_TAKE1("MDRequireHttps", md_config_set_require_https, NULL, RSRC_CONF|OR_AUTHCFG, 
+                  "Redirect non-secure requests to the https: equivalent."),
+    AP_INIT_RAW_ARGS("MDNotifyCmd", md_config_set_notify_cmd, NULL, RSRC_CONF, 
+                  "Set the command to run when signup/renew of domain is complete."),
+    AP_INIT_TAKE1("MDBaseServer", md_config_set_base_server, NULL, RSRC_CONF, 
+                  "Allow managing of base server outside virtual hosts."),
+    AP_INIT_RAW_ARGS("MDChallengeDns01", md_config_set_dns01_cmd, NULL, RSRC_CONF, 
+                  "Set the command for setup/teardown of dns-01 challenges"),
+    AP_INIT_TAKE1("MDCertificateFile", md_config_add_cert_file, NULL, RSRC_CONF, 
+                  "set the static certificate (chain) file to use for this domain."),
+    AP_INIT_TAKE1("MDCertificateKeyFile", md_config_add_key_file, NULL, RSRC_CONF, 
+                  "set the static private key file to use for this domain."),
+    AP_INIT_TAKE1("MDServerStatus", md_config_set_server_status, NULL, RSRC_CONF, 
+                  "On to see Managed Domains in server-status."),
+    AP_INIT_TAKE1("MDCertificateStatus", md_config_set_certificate_status, NULL, RSRC_CONF, 
+                  "On to see Managed Domain expose /.httpd/certificate-status."),
+    AP_INIT_TAKE1("MDWarnWindow", md_config_set_warn_window, NULL, RSRC_CONF, 
+                  "When less time remains for a certificate, send our/log a warning (defaults to days)"),
+    AP_INIT_RAW_ARGS("MDMessageCmd", md_config_set_msg_cmd, NULL, RSRC_CONF, 
+                  "Set the command run when a message about a domain is issued."),
+    AP_INIT_TAKE1("MDStapling", md_config_set_stapling, NULL, RSRC_CONF, 
+                  "Enable/Disable OCSP Stapling for this/all Managed Domain(s)."),
+    AP_INIT_TAKE1("MDStapleOthers", md_config_set_staple_others, NULL, RSRC_CONF, 
+                  "Enable/Disable OCSP Stapling for certificates not in Managed Domains."),
+    AP_INIT_TAKE1("MDStaplingKeepResponse", md_config_set_ocsp_keep_window, NULL, RSRC_CONF, 
+                  "The amount of time to keep an OCSP response in the store."),
+    AP_INIT_TAKE1("MDStaplingRenewWindow", md_config_set_ocsp_renew_window, NULL, RSRC_CONF, 
+                  "Time length for renewal before OCSP responses expire (defaults to days)."),
+    AP_INIT_TAKE2("MDCertificateCheck", md_config_set_cert_check, NULL, RSRC_CONF, 
+                  "Set name and URL pattern for a certificate monitoring site."),
+    AP_INIT_TAKE1("MDActivationDelay", md_config_set_activation_delay, NULL, RSRC_CONF, 
+                  "How long to delay activation of new certificates"),
+    AP_INIT_TAKE1("MDCACertificateFile", md_config_set_ca_certs, NULL, RSRC_CONF,
+                  "Set the CA file to use for connections"),
+    AP_INIT_TAKE12("MDExternalAccountBinding", md_config_set_eab, NULL, RSRC_CONF,
+                  "Set the external account binding keyid and hmac values to use at CA"),
+    AP_INIT_TAKE1("MDRetryDelay", md_config_set_min_delay, NULL, RSRC_CONF,
+                  "Time length for first retry, doubled on every consecutive error."),
+    AP_INIT_TAKE1("MDRetryFailover", md_config_set_retry_failover, NULL, RSRC_CONF,
+                  "The number of errors before a failover to another CA is triggered."),
+    AP_INIT_TAKE1("MDStoreLocks", md_config_set_store_locks, NULL, RSRC_CONF,
+                  "Configure locking of store for updates."),
+
+    AP_INIT_TAKE1(NULL, NULL, NULL, RSRC_CONF, NULL)
+};
+
+apr_status_t md_config_post_config(server_rec *s, apr_pool_t *p)
+{
+    md_srv_conf_t *sc;
+    md_mod_conf_t *mc;
+
+    sc = md_config_get(s);
+    mc = sc->mc;
+
+    mc->hsts_header = NULL;
+    if (mc->hsts_max_age > 0) {
+        mc->hsts_header = apr_psprintf(p, "max-age=%d", mc->hsts_max_age);
+    }
+
+#if AP_MODULE_MAGIC_AT_LEAST(20180906, 2)
+    if (mc->base_dir == NULL) {
+        mc->base_dir = ap_state_dir_relative(p, MD_DEFAULT_BASE_DIR);
+    }
+#endif
+    
+    return APR_SUCCESS;
+}
+
+static md_srv_conf_t *config_get_int(server_rec *s, apr_pool_t *p)
+{
+    md_srv_conf_t *sc = (md_srv_conf_t *)ap_get_module_config(s->module_config, &md_module);
+    ap_assert(sc);
+    if (sc->s != s && p) {
+        sc = md_config_merge(p, &defconf, sc);
+        sc->s = s;
+        sc->name = apr_pstrcat(p, CONF_S_NAME(s), sc->name, NULL);
+        sc->mc = md_mod_conf_get(p, 1);
+        ap_set_module_config(s->module_config, &md_module, sc);
+    }
+    return sc;
+}
+
+md_srv_conf_t *md_config_get(server_rec *s)
+{
+    return config_get_int(s, NULL);
+}
+
+md_srv_conf_t *md_config_get_unique(server_rec *s, apr_pool_t *p)
+{
+    assert(p);
+    return config_get_int(s, p);
+}
+
+md_srv_conf_t *md_config_cget(conn_rec *c)
+{
+    return md_config_get(c->base_server);
+}
+
+const char *md_config_gets(const md_srv_conf_t *sc, md_config_var_t var)
+{
+    switch (var) {
+        case MD_CONFIG_CA_CONTACT:
+            return sc->ca_contact? sc->ca_contact : defconf.ca_contact;
+        case MD_CONFIG_CA_PROTO:
+            return sc->ca_proto? sc->ca_proto : defconf.ca_proto;
+        case MD_CONFIG_BASE_DIR:
+            return sc->mc->base_dir;
+        case MD_CONFIG_PROXY:
+            return sc->mc->proxy_url;
+        case MD_CONFIG_CA_AGREEMENT:
+            return sc->ca_agreement? sc->ca_agreement : defconf.ca_agreement;
+        case MD_CONFIG_NOTIFY_CMD:
+            return sc->mc->notify_cmd;
+        default:
+            return NULL;
+    }
+}
+
+int md_config_geti(const md_srv_conf_t *sc, md_config_var_t var)
+{
+    switch (var) {
+        case MD_CONFIG_DRIVE_MODE:
+            return (sc->renew_mode != DEF_VAL)? sc->renew_mode : defconf.renew_mode;
+        case MD_CONFIG_TRANSITIVE:
+            return (sc->transitive != DEF_VAL)? sc->transitive : defconf.transitive;
+        case MD_CONFIG_REQUIRE_HTTPS:
+            return (sc->require_https != MD_REQUIRE_UNSET)? sc->require_https : defconf.require_https;
+        case MD_CONFIG_MUST_STAPLE:
+            return (sc->must_staple != DEF_VAL)? sc->must_staple : defconf.must_staple;
+        case MD_CONFIG_STAPLING:
+            return (sc->stapling != DEF_VAL)? sc->stapling : defconf.stapling;
+        case MD_CONFIG_STAPLE_OTHERS:
+            return (sc->staple_others != DEF_VAL)? sc->staple_others : defconf.staple_others;
+        default:
+            return 0;
+    }
+}
+
+void md_config_get_timespan(md_timeslice_t **pspan, const md_srv_conf_t *sc, md_config_var_t var)
+{
+    switch (var) {
+        case MD_CONFIG_RENEW_WINDOW:
+            *pspan = sc->renew_window? sc->renew_window : defconf.renew_window;
+            break;
+        case MD_CONFIG_WARN_WINDOW:
+            *pspan = sc->warn_window? sc->warn_window : defconf.warn_window;
+            break;
+        default:
+            break;
+    }
+}
+
+const md_t *md_get_for_domain(server_rec *s, const char *domain)
+{
+    md_srv_conf_t *sc;
+    const md_t *md;
+    int i;
+    
+    sc = md_config_get(s);
+    for (i = 0; sc && sc->assigned && i < sc->assigned->nelts; ++i) {
+        md = APR_ARRAY_IDX(sc->assigned, i, const md_t*);
+        if (md_contains(md, domain, 0)) goto leave;
+    }
+    md = NULL;
+leave:
+    return md;
+}
+
diff --git a/modules/md/mod_md_config.h b/modules/md/mod_md_config.h
new file mode 100644
index 0000000..de42169
--- /dev/null
+++ b/modules/md/mod_md_config.h
@@ -0,0 +1,132 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_config_h
+#define mod_md_md_config_h
+
+struct apr_hash_t;
+struct md_store_t;
+struct md_reg_t;
+struct md_ocsp_reg_t;
+struct md_pkeys_spec_t;
+
+typedef enum {
+    MD_CONFIG_CA_CONTACT,
+    MD_CONFIG_CA_PROTO,
+    MD_CONFIG_BASE_DIR,
+    MD_CONFIG_CA_AGREEMENT,
+    MD_CONFIG_DRIVE_MODE,
+    MD_CONFIG_RENEW_WINDOW,
+    MD_CONFIG_WARN_WINDOW,
+    MD_CONFIG_TRANSITIVE,
+    MD_CONFIG_PROXY,
+    MD_CONFIG_REQUIRE_HTTPS,
+    MD_CONFIG_MUST_STAPLE,
+    MD_CONFIG_NOTIFY_CMD,
+    MD_CONFIG_MESSGE_CMD,
+    MD_CONFIG_STAPLING,
+    MD_CONFIG_STAPLE_OTHERS,
+} md_config_var_t;
+
+typedef struct md_mod_conf_t md_mod_conf_t;
+struct md_mod_conf_t {
+    apr_array_header_t *mds;           /* all md_t* defined in the config, shared */
+    const char *base_dir;              /* base dir for store */
+    const char *proxy_url;             /* proxy url to use (or NULL) */
+    struct md_reg_t *reg;              /* md registry instance */
+    struct md_ocsp_reg_t *ocsp;        /* ocsp status registry */
+
+    int local_80;                      /* On which port http:80 arrives */
+    int local_443;                     /* On which port https:443 arrives */
+    int can_http;                      /* Does someone listen to the local port 80 equivalent? */
+    int can_https;                     /* Does someone listen to the local port 443 equivalent? */
+    int manage_base_server;            /* If base server outside vhost may be managed */
+    int hsts_max_age;                  /* max-age of HSTS (rfc6797) header */
+    const char *hsts_header;           /* computed HTST header to use or NULL */
+    apr_array_header_t *unused_names;  /* post config, names of all MDs not assigned to a vhost */
+    struct apr_hash_t *init_errors;    /* init errors reported with MD name as key */
+
+    const char *notify_cmd;            /* notification command to execute on signup/renew */
+    const char *message_cmd;           /* message command to execute on signup/renew/warnings */
+    struct apr_table_t *env;           /* environment for operation */
+    int dry_run;                       /* != 0 iff config dry run */
+    int server_status_enabled;         /* if module should add to server-status handler */
+    int certificate_status_enabled;    /* if module should expose /.httpd/certificate-status */
+    md_timeslice_t *ocsp_keep_window;  /* time that we keep ocsp responses around */
+    md_timeslice_t *ocsp_renew_window; /* time before exp. that we start renewing ocsp resp. */
+    const char *cert_check_name;       /* name of the linked certificate check site */
+    const char *cert_check_url;        /* url "template for" checking a certificate */
+    const char *ca_certs;              /* root certificates to use for connections */
+    apr_time_t min_delay;              /* minimum delay for retries */
+    int retry_failover;                /* number of errors to trigger CA failover */
+    int use_store_locks;               /* use locks when updating store */
+    apr_time_t lock_wait_timeout;      /* fail after this time when unable to obtain lock */
+};
+
+typedef struct md_srv_conf_t {
+    const char *name;
+    const server_rec *s;               /* server this config belongs to */
+    md_mod_conf_t *mc;                 /* global config settings */
+    
+    int transitive;                    /* != 0 iff VirtualHost names/aliases are auto-added */
+    md_require_t require_https;        /* If MDs require https: access */
+    int renew_mode;                    /* mode of obtaining credentials */
+    int must_staple;                   /* certificates should set the OCSP Must Staple extension */
+    struct md_pkeys_spec_t *pks;       /* specification for private keys */
+    md_timeslice_t *renew_window;      /* time before expiration that starts renewal */
+    md_timeslice_t *warn_window;       /* time before expiration that warning are sent out */
+    
+    struct apr_array_header_t *ca_urls; /* urls of CAs */
+    const char *ca_contact;            /* contact email registered to account */
+    const char *ca_proto;              /* protocol used vs CA (e.g. ACME) */
+    const char *ca_agreement;          /* accepted agreement uri between CA and user */ 
+    struct apr_array_header_t *ca_challenges; /* challenge types configured */
+    const char *ca_eab_kid;            /* != NULL, external account binding keyid */
+    const char *ca_eab_hmac;           /* != NULL, external account binding hmac */
+
+    int stapling;                      /* OCSP stapling enabled */
+    int staple_others;                 /* Provide OCSP stapling for non-MD certificates */
+
+    const char *dns01_cmd;             /* DNS challenge command, override global command */
+
+    md_t *current;                     /* md currently defined in <MDomainSet xxx> section */
+    struct apr_array_header_t *assigned; /* post_config: MDs that apply to this server */
+    int is_ssl;                        /* SSLEngine is enabled here */
+} md_srv_conf_t;
+
+void *md_config_create_svr(apr_pool_t *pool, server_rec *s);
+void *md_config_merge_svr(apr_pool_t *pool, void *basev, void *addv);
+
+extern const command_rec md_cmds[];
+
+apr_status_t md_config_post_config(server_rec *s, apr_pool_t *p);
+
+/* Get the effective md configuration for the connection */
+md_srv_conf_t *md_config_cget(conn_rec *c);
+/* Get the effective md configuration for the server */
+md_srv_conf_t *md_config_get(server_rec *s);
+/* Get the effective md configuration for the server, but make it
+ * unique to this server_rec, so that any changes only affect this server */
+md_srv_conf_t *md_config_get_unique(server_rec *s, apr_pool_t *p);
+
+const char *md_config_gets(const md_srv_conf_t *config, md_config_var_t var);
+int md_config_geti(const md_srv_conf_t *config, md_config_var_t var);
+
+void md_config_get_timespan(md_timeslice_t **pspan, const md_srv_conf_t *sc, md_config_var_t var);
+
+const md_t *md_get_for_domain(server_rec *s, const char *domain);
+
+#endif /* md_config_h */
diff --git a/modules/md/mod_md_drive.c b/modules/md/mod_md_drive.c
new file mode 100644
index 0000000..5565f44
--- /dev/null
+++ b/modules/md/mod_md_drive.c
@@ -0,0 +1,345 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <apr_optional.h>
+#include <apr_hash.h>
+#include <apr_strings.h>
+#include <apr_date.h>
+
+#include <httpd.h>
+#include <http_core.h>
+#include <http_protocol.h>
+#include <http_request.h>
+#include <http_log.h>
+
+#include "mod_watchdog.h"
+
+#include "md.h"
+#include "md_curl.h"
+#include "md_crypt.h"
+#include "md_event.h"
+#include "md_http.h"
+#include "md_json.h"
+#include "md_status.h"
+#include "md_store.h"
+#include "md_store_fs.h"
+#include "md_log.h"
+#include "md_result.h"
+#include "md_reg.h"
+#include "md_util.h"
+#include "md_version.h"
+#include "md_acme.h"
+#include "md_acme_authz.h"
+
+#include "mod_md.h"
+#include "mod_md_private.h"
+#include "mod_md_config.h"
+#include "mod_md_status.h"
+#include "mod_md_drive.h"
+
+/**************************************************************************************************/
+/* watchdog based impl. */
+
+#define MD_RENEW_WATCHDOG_NAME   "_md_renew_"
+
+static APR_OPTIONAL_FN_TYPE(ap_watchdog_get_instance) *wd_get_instance;
+static APR_OPTIONAL_FN_TYPE(ap_watchdog_register_callback) *wd_register_callback;
+static APR_OPTIONAL_FN_TYPE(ap_watchdog_set_callback_interval) *wd_set_interval;
+
+struct md_renew_ctx_t {
+    apr_pool_t *p;
+    server_rec *s;
+    md_mod_conf_t *mc;
+    ap_watchdog_t *watchdog;
+    
+    apr_array_header_t *jobs;
+};
+
+static void process_drive_job(md_renew_ctx_t *dctx, md_job_t *job, apr_pool_t *ptemp)
+{
+    const md_t *md;
+    md_result_t *result = NULL;
+    apr_status_t rv;
+    
+    md_job_load(job);
+    /* Evaluate again on loaded value. Values will change when watchdog switches child process */
+    if (apr_time_now() < job->next_run) return;
+    
+    job->next_run = 0;
+    if (job->finished && job->notified_renewed) {
+        /* finished and notification handled, nothing to do. */
+        goto leave;
+    }
+    
+    md = md_get_by_name(dctx->mc->mds, job->mdomain);
+    AP_DEBUG_ASSERT(md);
+
+    result = md_result_md_make(ptemp, md->name);
+    if (job->last_result) md_result_assign(result, job->last_result);
+    
+    if (md->state == MD_S_MISSING_INFORMATION) {
+        /* Missing information, this will not change until configuration
+         * is changed and server reloaded. */
+        job->fatal_error = 1;
+        job->next_run = 0;
+        goto leave;
+    }
+    
+    if (md_will_renew_cert(md)) {
+        /* Renew the MDs credentials in a STAGING area. Might be invoked repeatedly 
+         * without discarding previous/intermediate results.
+         * Only returns SUCCESS when the renewal is complete, e.g. STAGING has a
+         * complete set of new credentials.
+         */
+        ap_log_error( APLOG_MARK, APLOG_DEBUG, 0, dctx->s, APLOGNO(10052) 
+                     "md(%s): state=%d, driving", job->mdomain, md->state);
+
+        if (!md_reg_should_renew(dctx->mc->reg, md, dctx->p)) {
+            ap_log_error( APLOG_MARK, APLOG_DEBUG, 0, dctx->s, APLOGNO(10053) 
+                         "md(%s): no need to renew", job->mdomain);
+            goto expiry;
+        }
+    
+        /* The (possibly configured) event handler may veto renewals. This
+         * is used in cluster installtations, see #233. */
+        rv = md_event_raise("renewing", md->name, job, result, ptemp);
+        if (APR_SUCCESS != rv) {
+                ap_log_error(APLOG_MARK, APLOG_INFO, 0, dctx->s, APLOGNO(10060)
+                             "%s: event-handler for 'renewing' returned %d, preventing renewal to proceed.",
+                             job->mdomain, rv);
+                goto leave;
+        }
+
+        md_job_start_run(job, result, md_reg_store_get(dctx->mc->reg));
+        md_reg_renew(dctx->mc->reg, md, dctx->mc->env, 0, job->error_runs, result, ptemp);
+        md_job_end_run(job, result);
+        
+        if (APR_SUCCESS == result->status) {
+            /* Finished jobs might take a while before the results become valid.
+             * If that is in the future, request to run then */
+            if (apr_time_now() < result->ready_at) {
+                md_job_retry_at(job, result->ready_at);
+                goto leave;
+            }
+            
+            if (!job->notified_renewed) {
+                md_job_save(job, result, ptemp);
+                md_job_notify(job, "renewed", result);
+            }
+        }
+        else {
+            ap_log_error( APLOG_MARK, APLOG_ERR, result->status, dctx->s, APLOGNO(10056) 
+                         "processing %s: %s", job->mdomain, result->detail);
+            md_job_log_append(job, "renewal-error", result->problem, result->detail);
+            md_event_holler("errored", job->mdomain, job, result, ptemp);
+            ap_log_error(APLOG_MARK, APLOG_INFO, 0, dctx->s, APLOGNO(10057) 
+                         "%s: encountered error for the %d. time, next run in %s",
+                         job->mdomain, job->error_runs, 
+                         md_duration_print(ptemp, job->next_run - apr_time_now()));
+        }
+    }
+
+expiry:
+    if (!job->finished && md_reg_should_warn(dctx->mc->reg, md, dctx->p)) {
+        ap_log_error( APLOG_MARK, APLOG_TRACE1, 0, dctx->s,
+                     "md(%s): warn about expiration", md->name);
+        md_job_start_run(job, result, md_reg_store_get(dctx->mc->reg));
+        md_job_notify(job, "expiring", result);
+        md_job_end_run(job, result);
+    }
+
+leave:
+    if (job->dirty && result) {
+        rv = md_job_save(job, result, ptemp);
+        ap_log_error(APLOG_MARK, APLOG_TRACE1, rv, dctx->s, "%s: saving job props", job->mdomain);
+    }
+}
+
+int md_will_renew_cert(const md_t *md)
+{
+    if (md->renew_mode == MD_RENEW_MANUAL) {
+        return 0;
+    }
+    else if (md->renew_mode == MD_RENEW_AUTO && md->cert_files && md->cert_files->nelts) {
+        return 0;
+    } 
+    return 1;
+}
+
+static apr_time_t next_run_default(void)
+{
+    /* we'd like to run at least twice a day by default */
+    return apr_time_now() + apr_time_from_sec(MD_SECS_PER_DAY / 2);
+}
+
+static apr_status_t run_watchdog(int state, void *baton, apr_pool_t *ptemp)
+{
+    md_renew_ctx_t *dctx = baton;
+    md_job_t *job;
+    apr_time_t next_run, wait_time;
+    int i;
+    
+    /* mod_watchdog invoked us as a single thread inside the whole server (on this machine).
+     * This might be a repeated run inside the same child (mod_watchdog keeps affinity as
+     * long as the child lives) or another/new child.
+     */
+    switch (state) {
+        case AP_WATCHDOG_STATE_STARTING:
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, dctx->s, APLOGNO(10054)
+                         "md watchdog start, auto drive %d mds", dctx->jobs->nelts);
+            break;
+            
+        case AP_WATCHDOG_STATE_RUNNING:
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, dctx->s, APLOGNO(10055)
+                         "md watchdog run, auto drive %d mds", dctx->jobs->nelts);
+                         
+            /* Process all drive jobs. They will update their next_run property
+             * and we schedule ourself at the earliest of all. A job may specify 0
+             * as next_run to indicate that it wants to participate in the normal
+             * regular runs. */
+            next_run = next_run_default();
+            for (i = 0; i < dctx->jobs->nelts; ++i) {
+                job = APR_ARRAY_IDX(dctx->jobs, i, md_job_t *);
+                
+                if (apr_time_now() >= job->next_run) {
+                    process_drive_job(dctx, job, ptemp);
+                }
+                
+                if (job->next_run && job->next_run < next_run) {
+                    next_run = job->next_run;
+                }
+            }
+
+            wait_time = next_run - apr_time_now();
+            if (APLOGdebug(dctx->s)) {
+                ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, dctx->s, APLOGNO(10107)
+                             "next run in %s", md_duration_print(ptemp, wait_time));
+            }
+            wd_set_interval(dctx->watchdog, wait_time, dctx, run_watchdog);
+            break;
+            
+        case AP_WATCHDOG_STATE_STOPPING:
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, dctx->s, APLOGNO(10058)
+                         "md watchdog stopping");
+            break;
+    }
+    
+    return APR_SUCCESS;
+}
+
+apr_status_t md_renew_start_watching(md_mod_conf_t *mc, server_rec *s, apr_pool_t *p)
+{
+    apr_allocator_t *allocator;
+    md_renew_ctx_t *dctx;
+    apr_pool_t *dctxp;
+    apr_status_t rv;
+    md_t *md;
+    md_job_t *job;
+    int i;
+    
+    /* We use mod_watchdog to run a single thread in one of the child processes
+     * to monitor the MDs marked as watched, using the const data in the list
+     * mc->mds of our MD structures.
+     *
+     * The data in mc cannot be changed, as we may spawn copies in new child processes
+     * of the original data at any time. The child which hosts the watchdog thread
+     * may also die or be recycled, which causes a new watchdog thread to run
+     * in another process with the original data.
+     * 
+     * Instead, we use our store to persist changes in group STAGING. This is
+     * kept writable to child processes, but the data stored there is not live.
+     * However, mod_watchdog makes sure that we only ever have a single thread in
+     * our server (on this machine) that writes there. Other processes, e.g. informing
+     * the user about progress, only read from there.
+     *
+     * All changes during driving an MD are stored as files in MG_SG_STAGING/<MD.name>.
+     * All will have "md.json" and "job.json". There may be a range of other files used
+     * by the protocol obtaining the certificate/keys.
+     * 
+     * 
+     */
+    wd_get_instance = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_get_instance);
+    wd_register_callback = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_register_callback);
+    wd_set_interval = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_set_callback_interval);
+    
+    if (!wd_get_instance || !wd_register_callback || !wd_set_interval) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, 0, s, APLOGNO(10061) "mod_watchdog is required");
+        return !OK;
+    }
+    
+    /* We want our own pool with own allocator to keep data across watchdog invocations.
+     * Since we'll run in a single watchdog thread, using our own allocator will prevent 
+     * any confusion in the parent pool. */
+    apr_allocator_create(&allocator);
+    apr_allocator_max_free_set(allocator, 1);
+    rv = apr_pool_create_ex(&dctxp, p, NULL, allocator);
+    if (rv != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10062) "md_renew_watchdog: create pool");
+        return rv;
+    }
+    apr_allocator_owner_set(allocator, dctxp);
+    apr_pool_tag(dctxp, "md_renew_watchdog");
+
+    dctx = apr_pcalloc(dctxp, sizeof(*dctx));
+    dctx->p = dctxp;
+    dctx->s = s;
+    dctx->mc = mc;
+    
+    dctx->jobs = apr_array_make(dctx->p, mc->mds->nelts, sizeof(md_job_t *));
+    for (i = 0; i < mc->mds->nelts; ++i) {
+        md = APR_ARRAY_IDX(mc->mds, i, md_t*);
+        if (!md || !md->watched) continue;
+        
+        job = md_reg_job_make(mc->reg, md->name, p);
+        APR_ARRAY_PUSH(dctx->jobs, md_job_t*) = job;
+        ap_log_error( APLOG_MARK, APLOG_TRACE1, 0, dctx->s,  
+                     "md(%s): state=%d, created drive job", md->name, md->state);
+        
+        md_job_load(job);
+        if (job->error_runs) {
+            /* Server has just restarted. If we encounter an MD job with errors
+             * on a previous driving, we purge its STAGING area.
+             * This will reset the driving for the MD. It may run into the same
+             * error again, or in case of race/confusion/our error/CA error, it
+             * might allow the MD to succeed by a fresh start.
+             */
+            ap_log_error( APLOG_MARK, APLOG_NOTICE, 0, dctx->s, APLOGNO(10064) 
+                         "md(%s): previous drive job showed %d errors, purging STAGING "
+                         "area to reset.", md->name, job->error_runs);
+            md_store_purge(md_reg_store_get(dctx->mc->reg), p, MD_SG_STAGING, md->name);
+            md_store_purge(md_reg_store_get(dctx->mc->reg), p, MD_SG_CHALLENGES, md->name);
+            job->error_runs = 0;
+        }
+    }
+
+    if (!dctx->jobs->nelts) {
+        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(10065)
+                     "no managed domain to drive, no watchdog needed.");
+        apr_pool_destroy(dctx->p);
+        return APR_SUCCESS;
+    }
+    
+    if (APR_SUCCESS != (rv = wd_get_instance(&dctx->watchdog, MD_RENEW_WATCHDOG_NAME, 0, 1, dctx->p))) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(10066) 
+                     "create md renew watchdog(%s)", MD_RENEW_WATCHDOG_NAME);
+        return rv;
+    }
+    rv = wd_register_callback(dctx->watchdog, 0, dctx, run_watchdog);
+    ap_log_error(APLOG_MARK, rv? APLOG_CRIT : APLOG_DEBUG, rv, s, APLOGNO(10067) 
+                 "register md renew watchdog(%s)", MD_RENEW_WATCHDOG_NAME);
+    return rv;
+}
diff --git a/modules/md/mod_md_drive.h b/modules/md/mod_md_drive.h
new file mode 100644
index 0000000..40d6d67
--- /dev/null
+++ b/modules/md/mod_md_drive.h
@@ -0,0 +1,35 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_drive_h
+#define mod_md_md_drive_h
+
+struct md_mod_conf_t;
+struct md_reg_t;
+
+typedef struct md_renew_ctx_t md_renew_ctx_t;
+
+int md_will_renew_cert(const md_t *md);
+
+/**
+ * Start driving the certificate renewal for MDs marked with watched.
+ */
+apr_status_t md_renew_start_watching(struct md_mod_conf_t *mc, server_rec *s, apr_pool_t *p);
+
+
+
+
+#endif /* mod_md_md_drive_h */
diff --git a/modules/md/mod_md_ocsp.c b/modules/md/mod_md_ocsp.c
new file mode 100644
index 0000000..1d1e282
--- /dev/null
+++ b/modules/md/mod_md_ocsp.c
@@ -0,0 +1,272 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <apr_optional.h>
+#include <apr_time.h>
+#include <apr_date.h>
+#include <apr_strings.h>
+
+#include <httpd.h>
+#include <http_core.h>
+#include <http_log.h>
+#include <http_ssl.h>
+
+#include "mod_watchdog.h"
+
+#include "md.h"
+#include "md_crypt.h"
+#include "md_http.h"
+#include "md_json.h"
+#include "md_ocsp.h"
+#include "md_store.h"
+#include "md_log.h"
+#include "md_reg.h"
+#include "md_time.h"
+#include "md_util.h"
+
+#include "mod_md.h"
+#include "mod_md_config.h"
+#include "mod_md_private.h"
+#include "mod_md_ocsp.h"
+
+static int staple_here(md_srv_conf_t *sc) 
+{
+    if (!sc || !sc->mc->ocsp) return 0;
+    if (sc->assigned 
+        && sc->assigned->nelts == 1
+        && APR_ARRAY_IDX(sc->assigned, 0, const md_t*)->stapling) return 1;
+    return (md_config_geti(sc, MD_CONFIG_STAPLING) 
+            && md_config_geti(sc, MD_CONFIG_STAPLE_OTHERS));
+}
+
+int md_ocsp_prime_status(server_rec *s, apr_pool_t *p,
+                         const char *id, apr_size_t id_len, const char *pem)
+{
+    md_srv_conf_t *sc;
+    const md_t *md;
+    apr_array_header_t *chain;
+    apr_status_t rv = APR_ENOENT;
+
+    sc = md_config_get(s);
+    if (!staple_here(sc)) goto cleanup;
+
+    md = ((sc->assigned && sc->assigned->nelts == 1)?
+          APR_ARRAY_IDX(sc->assigned, 0, const md_t*) : NULL);
+    chain = apr_array_make(p, 5, sizeof(md_cert_t*));
+    rv = md_cert_read_chain(chain, p, pem, strlen(pem));
+    if (APR_SUCCESS != rv) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10268) "init stapling for: %s, "
+                     "unable to parse PEM data", md? md->name : s->server_hostname);
+        goto cleanup;
+    }
+    else if (chain->nelts < 2) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10269) "init stapling for: %s, "
+                     "need at least 2 certificates in PEM data", md? md->name : s->server_hostname);
+        rv = APR_EINVAL;
+        goto cleanup;
+    }
+
+    rv = md_ocsp_prime(sc->mc->ocsp, id, id_len,
+                       APR_ARRAY_IDX(chain, 0, md_cert_t*),
+                       APR_ARRAY_IDX(chain, 1, md_cert_t*), md);
+    ap_log_error(APLOG_MARK, APLOG_TRACE1, rv, s, "init stapling for: %s",
+                 md? md->name : s->server_hostname);
+
+cleanup:
+    return (APR_SUCCESS == rv)? OK : DECLINED;
+}
+
+typedef struct {
+    unsigned char *der;
+    apr_size_t der_len;
+} ocsp_copy_ctx_t;
+
+int md_ocsp_provide_status(server_rec *s, conn_rec *c,
+                           const char *id, apr_size_t id_len,
+                           ap_ssl_ocsp_copy_resp *cb, void *userdata)
+{
+    md_srv_conf_t *sc;
+    const md_t *md;
+    apr_status_t rv;
+
+    sc = md_config_get(s);
+    if (!staple_here(sc)) goto declined;
+
+    md = ((sc->assigned && sc->assigned->nelts == 1)?
+          APR_ARRAY_IDX(sc->assigned, 0, const md_t*) : NULL);
+    ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c, "get stapling for: %s",
+                  md? md->name : s->server_hostname);
+
+    rv = md_ocsp_get_status(cb, userdata, sc->mc->ocsp, id, id_len, c->pool, md);
+    if (APR_STATUS_IS_ENOENT(rv)) goto declined;
+    return OK;
+
+declined:
+    return DECLINED;
+}
+
+
+/**************************************************************************************************/
+/* watchdog based impl. */
+
+#define MD_OCSP_WATCHDOG_NAME   "_md_ocsp_"
+
+static APR_OPTIONAL_FN_TYPE(ap_watchdog_get_instance) *wd_get_instance;
+static APR_OPTIONAL_FN_TYPE(ap_watchdog_register_callback) *wd_register_callback;
+static APR_OPTIONAL_FN_TYPE(ap_watchdog_set_callback_interval) *wd_set_interval;
+
+typedef struct md_ocsp_ctx_t md_ocsp_ctx_t;
+
+struct md_ocsp_ctx_t {
+    apr_pool_t *p;
+    server_rec *s;
+    md_mod_conf_t *mc;
+    ap_watchdog_t *watchdog;
+};
+
+static apr_time_t next_run_default(void)
+{
+    /* we'd like to run at least hourly */
+    return apr_time_now() + apr_time_from_sec(MD_SECS_PER_HOUR);
+}
+
+static apr_status_t run_watchdog(int state, void *baton, apr_pool_t *ptemp)
+{
+    md_ocsp_ctx_t *octx = baton;
+    apr_time_t next_run, wait_time;
+    
+    /* mod_watchdog invoked us as a single thread inside the whole server (on this machine).
+     * This might be a repeated run inside the same child (mod_watchdog keeps affinity as
+     * long as the child lives) or another/new child.
+     */
+    switch (state) {
+        case AP_WATCHDOG_STATE_STARTING:
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, octx->s, APLOGNO(10197)
+                         "md ocsp watchdog start, ocsp stapling %d certificates", 
+                         (int)md_ocsp_count(octx->mc->ocsp));
+            break;
+            
+        case AP_WATCHDOG_STATE_RUNNING:
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, octx->s, APLOGNO(10198)
+                         "md ocsp watchdog run, ocsp stapling %d certificates", 
+                         (int)md_ocsp_count(octx->mc->ocsp));
+                         
+            /* Process all drive jobs. They will update their next_run property
+             * and we schedule ourself at the earliest of all. A job may specify 0
+             * as next_run to indicate that it wants to participate in the normal
+             * regular runs. */
+            next_run = next_run_default();
+            
+            md_ocsp_renew(octx->mc->ocsp, octx->p, ptemp, &next_run);
+            
+            wait_time = next_run - apr_time_now();
+            if (APLOGdebug(octx->s)) {
+                ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, octx->s, APLOGNO(10199)
+                             "md ocsp watchdog next run in %s", 
+                             md_duration_print(ptemp, wait_time));
+            }
+            wd_set_interval(octx->watchdog, wait_time, octx, run_watchdog);
+            break;
+            
+        case AP_WATCHDOG_STATE_STOPPING:
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, octx->s, APLOGNO(10200)
+                         "md ocsp watchdog stopping");
+            break;
+    }
+    
+    return APR_SUCCESS;
+}
+
+static apr_status_t ocsp_remove_old_responses(md_mod_conf_t *mc, apr_pool_t *p)
+{
+    md_timeperiod_t keep_norm, keep;
+    
+    keep_norm.end = apr_time_now();
+    keep_norm.start = keep_norm.end - MD_TIME_OCSP_KEEP_NORM;
+    keep = md_timeperiod_slice_before_end(&keep_norm, mc->ocsp_keep_window);
+    /* remove any ocsp response older than keep.start */
+    return md_ocsp_remove_responses_older_than(mc->ocsp, p, keep.start);
+}
+
+apr_status_t md_ocsp_start_watching(md_mod_conf_t *mc, server_rec *s, apr_pool_t *p)
+{
+    apr_allocator_t *allocator;
+    md_ocsp_ctx_t *octx;
+    apr_pool_t *octxp;
+    apr_status_t rv;
+    
+    wd_get_instance = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_get_instance);
+    wd_register_callback = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_register_callback);
+    wd_set_interval = APR_RETRIEVE_OPTIONAL_FN(ap_watchdog_set_callback_interval);
+    
+    if (!wd_get_instance || !wd_register_callback || !wd_set_interval) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, 0, s, APLOGNO(10201) 
+                     "mod_watchdog is required for OCSP stapling");
+        return APR_EGENERAL;
+    }
+    
+    /* We want our own pool with own allocator to keep data across watchdog invocations.
+     * Since we'll run in a single watchdog thread, using our own allocator will prevent 
+     * any confusion in the parent pool. */
+    apr_allocator_create(&allocator);
+    apr_allocator_max_free_set(allocator, 1);
+    rv = apr_pool_create_ex(&octxp, p, NULL, allocator);
+    if (rv != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(10205) "md_ocsp_watchdog: create pool");
+        return rv;
+    }
+    apr_allocator_owner_set(allocator, octxp);
+    apr_pool_tag(octxp, "md_ocsp_watchdog");
+
+    octx = apr_pcalloc(octxp, sizeof(*octx));
+    octx->p = octxp;
+    octx->s = s;
+    octx->mc = mc;
+    
+    /* Time for some house keeping, before the server goes live (again):
+     * - we store OCSP responses for each certificate individually by its SHA-1 id
+     * - this means, as long as certificate do not change, the number of response
+     *   files remains stable.
+     * - But when a certificate changes (is replaced), the response is obsolete
+     * - we do not get notified when a certificate is no longer used. An admin
+     *   might just reconfigure or change the content of a file (backup/restore etc.)
+     * - also, certificates might be added by some openssl config commands or other
+     *   modules that we do not immediately see right at startup. We cannot assume
+     *   that any OCSP response we cannot relate to a certificate RIGHT NOW, is no
+     *   longer needed.
+     * - since the response files are relatively small, we have no problem with
+     *   keeping them around for a while. We just do not want an ever growing store. 
+     * - The simplest and effective way seems to be to just remove files older
+     *   a certain amount of time. Take a 7 day default and let the admin configure
+     *   it for very special setups. 
+     */ 
+    ocsp_remove_old_responses(mc, octx->p);
+    
+    rv = wd_get_instance(&octx->watchdog, MD_OCSP_WATCHDOG_NAME, 0, 1, octx->p);
+    if (APR_SUCCESS != rv) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(10202) 
+                     "create md ocsp watchdog(%s)", MD_OCSP_WATCHDOG_NAME);
+        return rv;
+    }
+    rv = wd_register_callback(octx->watchdog, 0, octx, run_watchdog);
+    ap_log_error(APLOG_MARK, rv? APLOG_CRIT : APLOG_DEBUG, rv, s, APLOGNO(10203) 
+                 "register md ocsp watchdog(%s)", MD_OCSP_WATCHDOG_NAME);
+    return rv;
+}
+
+
+
diff --git a/modules/md/mod_md_ocsp.h b/modules/md/mod_md_ocsp.h
new file mode 100644
index 0000000..a3f9502
--- /dev/null
+++ b/modules/md/mod_md_ocsp.h
@@ -0,0 +1,33 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_ocsp_h
+#define mod_md_md_ocsp_h
+
+
+int md_ocsp_prime_status(server_rec *s, apr_pool_t *p,
+                         const char *id, apr_size_t id_len, const char *pem);
+
+int md_ocsp_provide_status(server_rec *s, conn_rec *c, const char *id, apr_size_t id_len,
+                           ap_ssl_ocsp_copy_resp *cb, void *userdata);
+
+/**
+ * Start watchdog for retrieving/updating ocsp status.
+ */
+apr_status_t md_ocsp_start_watching(struct md_mod_conf_t *mc, server_rec *s, apr_pool_t *p);
+
+
+#endif /* mod_md_md_ocsp_h */
diff --git a/modules/md/mod_md_os.c b/modules/md/mod_md_os.c
new file mode 100644
index 0000000..06a5bee
--- /dev/null
+++ b/modules/md/mod_md_os.c
@@ -0,0 +1,88 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+ 
+#include <assert.h>
+#include <apr_strings.h>
+
+#include <mpm_common.h>
+#include <httpd.h>
+#include <http_log.h>
+#include <ap_mpm.h>
+
+#if APR_HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#if AP_NEED_SET_MUTEX_PERMS
+#include "unixd.h"
+#endif
+
+#include "md_util.h"
+#include "mod_md_os.h"
+
+apr_status_t md_try_chown(const char *fname, unsigned int uid, int gid, apr_pool_t *p)
+{
+#if AP_NEED_SET_MUTEX_PERMS && HAVE_UNISTD_H
+    /* Since we only switch user when running as root, we only need to chown directories
+     * in that case. Otherwise, the server will ignore any "user/group" directives and
+     * child processes have the same privileges as the parent.
+     */
+    if (!geteuid()) {
+        if (-1 == chown(fname, (uid_t)uid, (gid_t)gid)) {
+            apr_status_t rv = APR_FROM_OS_ERROR(errno);
+            if (!APR_STATUS_IS_ENOENT(rv)) {
+                ap_log_perror(APLOG_MARK, APLOG_ERR, rv, p, APLOGNO(10082)
+                              "Can't change owner of %s", fname);
+            }
+            return rv;
+        }
+    }
+    return APR_SUCCESS;
+#else 
+    return APR_ENOTIMPL;
+#endif
+}
+
+apr_status_t md_make_worker_accessible(const char *fname, apr_pool_t *p)
+{
+#ifdef WIN32
+    return APR_ENOTIMPL;
+#else 
+    return md_try_chown(fname, ap_unixd_config.user_id, -1, p);
+#endif
+}
+
+#ifdef WIN32
+
+apr_status_t md_server_graceful(apr_pool_t *p, server_rec *s)
+{
+    return APR_ENOTIMPL;
+}
+ 
+#else
+
+apr_status_t md_server_graceful(apr_pool_t *p, server_rec *s)
+{ 
+    apr_status_t rv;
+    
+    (void)p;
+    (void)s;
+    rv = (kill(getppid(), AP_SIG_GRACEFUL) < 0)? APR_ENOTIMPL : APR_SUCCESS;
+    ap_log_error(APLOG_MARK, APLOG_TRACE1, errno, NULL, "sent signal to parent");
+    return rv;
+}
+
+#endif
+
diff --git a/modules/md/mod_md_os.h b/modules/md/mod_md_os.h
new file mode 100644
index 0000000..3085076
--- /dev/null
+++ b/modules/md/mod_md_os.h
@@ -0,0 +1,37 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_os_h
+#define mod_md_md_os_h
+
+/**
+ * Try chown'ing the file/directory. Give id -1 to not change uid/gid.
+ * Will return APR_ENOTIMPL on platforms not supporting this operation.
+ */
+apr_status_t md_try_chown(const char *fname, unsigned int uid, int gid, apr_pool_t *p);
+
+/**
+ * Make a file or directory read/write(/searchable) by httpd workers.
+ */
+apr_status_t md_make_worker_accessible(const char *fname, apr_pool_t *p);
+
+/**
+ * Trigger a graceful restart of the server. Depending on the architecture, may
+ * return APR_ENOTIMPL.
+ */
+apr_status_t md_server_graceful(apr_pool_t *p, server_rec *s);
+
+#endif /* mod_md_md_os_h */
diff --git a/modules/md/mod_md_private.h b/modules/md/mod_md_private.h
new file mode 100644
index 0000000..45521ea
--- /dev/null
+++ b/modules/md/mod_md_private.h
@@ -0,0 +1,24 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_private_h
+#define mod_md_md_private_h
+
+extern module AP_MODULE_DECLARE_DATA md_module;
+
+APLOG_USE_MODULE(md);
+
+#endif
diff --git a/modules/md/mod_md_status.c b/modules/md/mod_md_status.c
new file mode 100644
index 0000000..2286051
--- /dev/null
+++ b/modules/md/mod_md_status.c
@@ -0,0 +1,987 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <assert.h>
+#include <apr_optional.h>
+#include <apr_time.h>
+#include <apr_date.h>
+#include <apr_strings.h>
+
+#include <httpd.h>
+#include <http_core.h>
+#include <http_protocol.h>
+#include <http_request.h>
+#include <http_log.h>
+
+#include "mod_status.h"
+
+#include "md.h"
+#include "md_curl.h"
+#include "md_crypt.h"
+#include "md_http.h"
+#include "md_ocsp.h"
+#include "md_json.h"
+#include "md_status.h"
+#include "md_store.h"
+#include "md_store_fs.h"
+#include "md_log.h"
+#include "md_reg.h"
+#include "md_util.h"
+#include "md_version.h"
+#include "md_acme.h"
+#include "md_acme_authz.h"
+
+#include "mod_md.h"
+#include "mod_md_private.h"
+#include "mod_md_config.h"
+#include "mod_md_drive.h"
+#include "mod_md_status.h"
+
+/**************************************************************************************************/
+/* Certificate status */
+
+#define APACHE_PREFIX               "/.httpd/"
+#define MD_STATUS_RESOURCE          APACHE_PREFIX"certificate-status"
+#define HTML_STATUS(X)              (!((X)->flags & AP_STATUS_SHORT))
+
+int md_http_cert_status(request_rec *r)
+{
+    int i;
+    md_json_t *resp, *mdj, *cj;
+    const md_srv_conf_t *sc;
+    const md_t *md;
+    md_pkey_spec_t *spec;
+    const char *keyname;
+    apr_bucket_brigade *bb;
+    apr_status_t rv;
+
+    if (!r->parsed_uri.path || strcmp(MD_STATUS_RESOURCE, r->parsed_uri.path))
+        return DECLINED;
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
+                  "requesting status for: %s", r->hostname);
+
+    /* We are looking for information about a staged certificate */
+    sc = ap_get_module_config(r->server->module_config, &md_module);
+    if (!sc || !sc->mc || !sc->mc->reg || !sc->mc->certificate_status_enabled) return DECLINED;
+    md = md_get_by_domain(sc->mc->mds, r->hostname);
+    if (!md) return DECLINED;
+
+    if (r->method_number != M_GET) {
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
+                      "md(%s): status supports only GET", md->name);
+        return HTTP_NOT_IMPLEMENTED;
+    }
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
+                  "requesting status for MD: %s", md->name);
+
+    rv = md_status_get_md_json(&mdj, md, sc->mc->reg, sc->mc->ocsp, r->pool);
+    if (APR_SUCCESS != rv) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(10204)
+                      "loading md status for %s", md->name);
+        return HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
+                  "status for MD: %s is %s", md->name, md_json_writep(mdj, r->pool, MD_JSON_FMT_INDENT));
+
+    resp = md_json_create(r->pool);
+
+    if (md_json_has_key(mdj, MD_KEY_CERT, MD_KEY_VALID, NULL)) {
+         md_json_setj(md_json_getj(mdj, MD_KEY_CERT, MD_KEY_VALID, NULL), resp, MD_KEY_VALID, NULL);
+     }
+
+    for (i = 0; i < md_cert_count(md); ++i) {
+        spec = md_pkeys_spec_get(md->pks, i);
+        keyname = md_pkey_spec_name(spec);
+        cj = md_json_create(r->pool);
+
+        if (md_json_has_key(mdj, MD_KEY_CERT, keyname, MD_KEY_VALID, NULL)) {
+            md_json_setj(md_json_getj(mdj, MD_KEY_CERT, keyname, MD_KEY_VALID, NULL),
+                         cj, MD_KEY_VALID, NULL);
+        }
+
+        if (md_json_has_key(mdj, MD_KEY_CERT, keyname, MD_KEY_SERIAL, NULL)) {
+            md_json_sets(md_json_gets(mdj, MD_KEY_CERT, keyname, MD_KEY_SERIAL, NULL),
+                         cj, MD_KEY_SERIAL, NULL);
+        }
+        if (md_json_has_key(mdj, MD_KEY_CERT, keyname, MD_KEY_SHA256_FINGERPRINT, NULL)) {
+            md_json_sets(md_json_gets(mdj, MD_KEY_CERT, keyname, MD_KEY_SHA256_FINGERPRINT, NULL),
+                         cj, MD_KEY_SHA256_FINGERPRINT, NULL);
+        }
+        md_json_setj(cj, resp, keyname, NULL );
+    }
+
+    if (md_json_has_key(mdj, MD_KEY_RENEWAL, NULL)) {
+           /* copy over the information we want to make public about this:
+            *  - when not finished, add an empty object to indicate something is going on
+            *  - when a certificate is staged, add the information from that */
+           cj = md_json_getj(mdj, MD_KEY_RENEWAL, MD_KEY_CERT, NULL);
+           cj = cj? cj : md_json_create(r->pool);
+           md_json_setj(cj, resp, MD_KEY_RENEWAL, MD_KEY_CERT, NULL);
+     }
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "md[%s]: sending status", md->name);
+    apr_table_set(r->headers_out, "Content-Type", "application/json");
+    bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
+    md_json_writeb(resp, MD_JSON_FMT_INDENT, bb);
+    ap_pass_brigade(r->output_filters, bb);
+    apr_brigade_cleanup(bb);
+
+    return DONE;
+}
+
+/**************************************************************************************************/
+/* Status hook */
+
+typedef struct {
+    apr_pool_t *p;
+    const md_mod_conf_t *mc;
+    apr_bucket_brigade *bb;
+    int flags;
+    const char *prefix;
+    const char *separator;
+} status_ctx;
+
+typedef struct status_info status_info;
+
+static void add_json_val(status_ctx *ctx, md_json_t *j);
+
+typedef void add_status_fn(status_ctx *ctx, md_json_t *mdj, const status_info *info);
+
+struct status_info {
+    const char *label;
+    const char *key;
+    add_status_fn *fn;
+};
+
+static void si_val_status(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    const char *s = "unknown";
+    apr_time_t until;
+    (void)info;
+    switch (md_json_getl(mdj, info->key, NULL)) {
+        case MD_S_INCOMPLETE:
+            s = md_json_gets(mdj, MD_KEY_STATE_DESCR, NULL);
+            s = s? apr_psprintf(ctx->p, "incomplete: %s", s) : "incomplete";
+            break;
+        case MD_S_EXPIRED_DEPRECATED:
+        case MD_S_COMPLETE:
+            until = md_json_get_time(mdj, MD_KEY_CERT, MD_KEY_VALID, MD_KEY_UNTIL, NULL);
+            s = (!until || until > apr_time_now())? "good" : "expired";
+            break;
+        case MD_S_ERROR: s = "error"; break;
+        case MD_S_MISSING_INFORMATION: s = "missing information"; break;
+        default: break;
+    }
+    if (HTML_STATUS(ctx)) {
+        apr_brigade_puts(ctx->bb, NULL, NULL, s);
+    }
+    else {
+        apr_brigade_printf(ctx->bb, NULL, NULL, "%s%s: %s\n",
+                           ctx->prefix, info->label, s);
+    }
+}
+
+static void si_val_url(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    const char *url, *s;
+
+    s = url = md_json_gets(mdj, info->key, NULL);
+    if (!url) return;
+    s = md_get_ca_name_from_url(ctx->p, url);
+    if (HTML_STATUS(ctx)) {
+        apr_brigade_printf(ctx->bb, NULL, NULL, "<a href='%s'>%s</a>",
+                           ap_escape_html2(ctx->p, url, 1),
+                           ap_escape_html2(ctx->p, s, 1));
+    }
+    else {
+        apr_brigade_printf(ctx->bb, NULL, NULL, "%s%sName: %s\n",
+                           ctx->prefix, info->label, s);
+        apr_brigade_printf(ctx->bb, NULL, NULL, "%s%sURL: %s\n",
+                           ctx->prefix, info->label, url);
+    }
+}
+
+static void print_date(status_ctx *ctx, apr_time_t timestamp, const char *title)
+{
+    apr_bucket_brigade *bb = ctx->bb;
+    if (timestamp > 0) {
+        char ts[128];
+        char ts2[128];
+        apr_time_exp_t texp;
+        apr_size_t len;
+
+        apr_time_exp_gmt(&texp, timestamp);
+        apr_strftime(ts, &len, sizeof(ts2)-1, "%Y-%m-%d", &texp);
+        ts[len] = '\0';
+        if (!title) {
+            apr_strftime(ts2, &len, sizeof(ts)-1, "%Y-%m-%dT%H:%M:%SZ", &texp);
+            ts2[len] = '\0';
+            title = ts2;
+        }
+        if (HTML_STATUS(ctx)) {
+            apr_brigade_printf(bb, NULL, NULL,
+                               "<span title='%s' style='white-space: nowrap;'>%s</span>",
+                               ap_escape_html2(bb->p, title, 1), ts);
+        }
+        else {
+            apr_brigade_printf(bb, NULL, NULL, "%s%s: %s\n",
+                               ctx->prefix, title, ts);
+        }
+    }
+}
+
+static void print_time(status_ctx *ctx, const char *label, apr_time_t t)
+{
+    apr_bucket_brigade *bb = ctx->bb;
+    apr_time_t now;
+    const char *pre, *post, *sep;
+    char ts[APR_RFC822_DATE_LEN];
+    char ts2[128];
+    apr_time_exp_t texp;
+    apr_size_t len;
+    apr_interval_time_t delta;
+
+    if (t == 0) {
+        /* timestamp is 0, we use that for "not set" */
+        return;
+    }
+    apr_time_exp_gmt(&texp, t);
+    now = apr_time_now();
+    pre = post = "";
+    sep = (label && strlen(label))? " " : "";
+    delta = 0;
+    if (HTML_STATUS(ctx)) {
+        apr_rfc822_date(ts, t);
+        if (t > now) {
+            delta = t - now;
+            pre = "in ";
+        }
+        else {
+            delta = now - t;
+            post = " ago";
+        }
+        if (delta >= (4 * apr_time_from_sec(MD_SECS_PER_DAY))) {
+            apr_strftime(ts2, &len, sizeof(ts2)-1, "%Y-%m-%d", &texp);
+            ts2[len] = '\0';
+            apr_brigade_printf(bb, NULL, NULL, "%s%s<span title='%s' "
+                               "style='white-space: nowrap;'>%s</span>",
+                               label, sep, ts, ts2);
+        }
+        else {
+            apr_brigade_printf(bb, NULL, NULL, "%s%s<span title='%s'>%s%s%s</span>",
+                               label, sep, ts, pre, md_duration_roughly(bb->p, delta), post);
+        }
+    }
+    else {
+        delta = t - now;
+        apr_brigade_printf(bb, NULL, NULL, "%s%s: %" APR_TIME_T_FMT "\n",
+                           ctx->prefix, label, apr_time_sec(delta));
+    }
+}
+
+static void si_val_valid_time(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    const char *sfrom, *suntil, *sep, *title;
+    apr_time_t from, until;
+
+    sep = NULL;
+    sfrom = md_json_gets(mdj, info->key, MD_KEY_FROM, NULL);
+    from = sfrom? apr_date_parse_rfc(sfrom) : 0;
+    suntil = md_json_gets(mdj, info->key, MD_KEY_UNTIL, NULL);
+    until = suntil?apr_date_parse_rfc(suntil) : 0;
+
+    if (HTML_STATUS(ctx)) {
+        if (from > apr_time_now()) {
+            apr_brigade_puts(ctx->bb, NULL, NULL, "from ");
+            print_date(ctx, from, sfrom);
+            sep = " ";
+        }
+        if (until) {
+            if (sep) apr_brigade_puts(ctx->bb, NULL, NULL, sep);
+            apr_brigade_puts(ctx->bb, NULL, NULL, "until ");
+            title = sfrom? apr_psprintf(ctx->p, "%s - %s", sfrom, suntil) : suntil;
+            print_date(ctx, until, title);
+        }
+    }
+    else {
+        if (from > apr_time_now()) {
+            print_date(ctx, from,
+            apr_pstrcat(ctx->p, info->label, "From", NULL));
+        }
+        if (until) {
+            print_date(ctx, from,
+            apr_pstrcat(ctx->p, info->label, "Until", NULL));
+        }
+    }
+}
+
+static void si_add_header(status_ctx *ctx, const status_info *info)
+{
+    if (HTML_STATUS(ctx)) {
+        const char *html = ap_escape_html2(ctx->p, info->label, 1);
+        apr_brigade_printf(ctx->bb, NULL, NULL, "<th class=\"%s\">%s</th>", html, html);
+    }
+}
+
+static void si_val_cert_valid_time(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    md_json_t *jcert;
+    status_info sub = *info;
+
+    sub.key = MD_KEY_VALID;
+    jcert = md_json_getj(mdj, info->key, NULL);
+    if (jcert) si_val_valid_time(ctx, jcert, &sub);
+}
+
+static void val_url_print(status_ctx *ctx, const status_info *info,
+                          const char*url, const char *proto, int i)
+{
+    const char *s;
+
+    if (proto && !strcmp(proto, "tailscale")) {
+        s = "tailscale";
+    }
+    else if (url) {
+        s = md_get_ca_name_from_url(ctx->p, url);
+    }
+    else {
+        return;
+    }
+    if (HTML_STATUS(ctx)) {
+        apr_brigade_printf(ctx->bb, NULL, NULL, "%s<a href='%s'>%s</a>",
+                           i? " " : "",
+                           ap_escape_html2(ctx->p, url, 1),
+                           ap_escape_html2(ctx->p, s, 1));
+    }
+    else if (i == 0) {
+        apr_brigade_printf(ctx->bb, NULL, NULL, "%s%sName: %s\n",
+                           ctx->prefix, info->label, s);
+        apr_brigade_printf(ctx->bb, NULL, NULL, "%s%sURL: %s\n",
+                           ctx->prefix, info->label, url);
+    }
+    else {
+        apr_brigade_printf(ctx->bb, NULL, NULL, "%s%sName%d: %s\n",
+                           ctx->prefix, info->label, i, s);
+        apr_brigade_printf(ctx->bb, NULL, NULL, "%s%sURL%d: %s\n",
+                           ctx->prefix, info->label, i, url);
+    }
+}
+
+static void si_val_ca_urls(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    md_json_t *jcert;
+    const char *proto, *url;
+    apr_array_header_t *urls;
+    int i;
+
+    jcert = md_json_getj(mdj, info->key, NULL);
+    if (!jcert) {
+        return;
+    }
+
+    proto = md_json_gets(jcert, MD_KEY_PROTO, NULL);
+    url = md_json_gets(jcert, MD_KEY_URL, NULL);
+    if (url) {
+        /* print the effective CA url used, if set */
+        val_url_print(ctx, info, url, proto, 0);
+    }
+    else {
+        /* print the available CA urls configured */
+        urls = apr_array_make(ctx->p, 3, sizeof(const char*));
+        md_json_getsa(urls, jcert, MD_KEY_URLS, NULL);
+        for (i = 0; i < urls->nelts; ++i) {
+            url = APR_ARRAY_IDX(urls, i, const char*);
+            val_url_print(ctx, info, url, proto, i);
+        }
+    }
+}
+
+static int count_certs(void *baton, const char *key, md_json_t *json)
+{
+    int *pcount = baton;
+
+    (void)json;
+    if (strcmp(key, MD_KEY_VALID)) {
+        *pcount += 1;
+    }
+    return 1;
+}
+
+static void print_job_summary(status_ctx *ctx, md_json_t *mdj, const char *key,
+                              const char *separator)
+{
+    apr_bucket_brigade *bb = ctx->bb;
+    char buffer[HUGE_STRING_LEN];
+    apr_status_t rv;
+    int finished, errors, cert_count;
+    apr_time_t t;
+    const char *s, *line;
+
+    if (!md_json_has_key(mdj, key, NULL)) {
+        return;
+    }
+
+    finished = md_json_getb(mdj, key, MD_KEY_FINISHED, NULL);
+    errors = (int)md_json_getl(mdj, key, MD_KEY_ERRORS, NULL);
+    rv = (apr_status_t)md_json_getl(mdj, key, MD_KEY_LAST, MD_KEY_STATUS, NULL);
+
+    line = separator? separator : "";
+
+    if (rv != APR_SUCCESS) {
+        char *errstr = apr_strerror(rv, buffer, sizeof(buffer));
+        s = md_json_gets(mdj, key, MD_KEY_LAST, MD_KEY_PROBLEM, NULL);
+        if (HTML_STATUS(ctx)) {
+            line = apr_psprintf(bb->p, "%s Error[%s]: %s", line,
+                                errstr, s? s : "");
+        }
+        else {
+            apr_brigade_printf(bb, NULL, NULL, "%sLastStatus: %s\n", ctx->prefix, errstr);
+            apr_brigade_printf(bb, NULL, NULL, "%sLastProblem: %s\n", ctx->prefix, s);
+        }
+    }
+
+    if (!HTML_STATUS(ctx)) {
+        apr_brigade_printf(bb, NULL, NULL, "%sFinished: %s\n", ctx->prefix,
+                           finished ? "yes" : "no");
+    }
+    if (finished) {
+        cert_count = 0;
+        md_json_iterkey(count_certs, &cert_count, mdj, key, MD_KEY_CERT, NULL);
+        if (HTML_STATUS(ctx)) {
+            if (cert_count > 0) {
+                line =apr_psprintf(bb->p, "%s  finished, %d new certificate%s staged.",
+                                   line, cert_count, cert_count > 1? "s" : "");
+            }
+            else {
+                line = apr_psprintf(bb->p, "%s  finished successfully.", line);
+            }
+        }
+        else {
+            apr_brigade_printf(bb, NULL, NULL, "%sNewStaged: %d\n", ctx->prefix, cert_count);
+        }
+    }
+    else {
+        s = md_json_gets(mdj, key, MD_KEY_LAST, MD_KEY_DETAIL, NULL);
+        if (s) {
+            if (HTML_STATUS(ctx)) {
+                line = apr_psprintf(bb->p, "%s %s", line, s);
+            }
+            else {
+                apr_brigade_printf(bb, NULL, NULL, "%sLastDetail: %s\n", ctx->prefix, s);
+            }
+        }
+    }
+
+    errors = (int)md_json_getl(mdj, MD_KEY_ERRORS, NULL);
+    if (errors > 0) {
+        if (HTML_STATUS(ctx)) {
+            line = apr_psprintf(bb->p, "%s (%d retr%s) ", line,
+                                errors, (errors > 1)? "y" : "ies");
+        }
+        else {
+            apr_brigade_printf(bb, NULL, NULL, "%sRetries: %d\n", ctx->prefix, errors);
+        }
+    }
+
+    if (HTML_STATUS(ctx)) {
+        apr_brigade_puts(bb, NULL, NULL, line);
+    }
+
+    t = md_json_get_time(mdj, key, MD_KEY_NEXT_RUN, NULL);
+    if (t > apr_time_now() && !finished) {
+        print_time(ctx,
+                   HTML_STATUS(ctx) ? "\nNext run" : "NextRun",
+                   t);
+    }
+    else if (line[0] != '\0') {
+        if (HTML_STATUS(ctx)) {
+            apr_brigade_puts(bb, NULL, NULL, "\nOngoing...");
+        }
+        else {
+            apr_brigade_printf(bb, NULL, NULL, "%s: Ongoing\n", ctx->prefix);
+        }
+    }
+}
+
+static void si_val_activity(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    apr_time_t t;
+    const char *prefix = ctx->prefix;
+
+    (void)info;
+    if (!HTML_STATUS(ctx)) {
+        ctx->prefix = apr_pstrcat(ctx->p, prefix, info->label, NULL);
+    }
+
+    if (md_json_has_key(mdj, MD_KEY_RENEWAL, NULL)) {
+        print_job_summary(ctx, mdj, MD_KEY_RENEWAL, NULL);
+        return;
+    }
+
+    t = md_json_get_time(mdj, MD_KEY_RENEW_AT, NULL);
+    if (t > apr_time_now()) {
+        print_time(ctx, "Renew", t);
+    }
+    else if (t) {
+        if (HTML_STATUS(ctx)) {
+            apr_brigade_puts(ctx->bb, NULL, NULL, "Pending");
+        }
+        else {
+            apr_brigade_printf(ctx->bb, NULL, NULL, "%s: %s", ctx->prefix, "Pending");
+        }
+    }
+    else if (MD_RENEW_MANUAL == md_json_getl(mdj, MD_KEY_RENEW_MODE, NULL)) {
+        if (HTML_STATUS(ctx)) {
+            apr_brigade_puts(ctx->bb, NULL, NULL, "Manual renew");
+        }
+        else {
+            apr_brigade_printf(ctx->bb, NULL, NULL, "%s: %s", ctx->prefix, "Manual renew");
+        }
+    }
+    if (!HTML_STATUS(ctx)) {
+        ctx->prefix = prefix;
+    }
+}
+
+static int cert_check_iter(void *baton, const char *key, md_json_t *json)
+{
+    status_ctx *ctx = baton;
+    const char *fingerprint;
+
+    fingerprint = md_json_gets(json, MD_KEY_SHA256_FINGERPRINT, NULL);
+    if (fingerprint) {
+        if (HTML_STATUS(ctx)) {
+            apr_brigade_printf(ctx->bb, NULL, NULL,
+                               "<a href=\"%s%s\">%s[%s]</a><br>",
+                               ctx->mc->cert_check_url, fingerprint,
+                               ctx->mc->cert_check_name, key);
+        }
+        else {
+            apr_brigade_printf(ctx->bb, NULL, NULL,
+                               "%sType: %s\n",
+                               ctx->prefix,
+                               key);
+            apr_brigade_printf(ctx->bb, NULL, NULL,
+                               "%sName: %s\n",
+                               ctx->prefix,
+                               ctx->mc->cert_check_name);
+            apr_brigade_printf(ctx->bb, NULL, NULL,
+                               "%sURL: %s%s\n",
+                               ctx->prefix,
+                               ctx->mc->cert_check_url, fingerprint);
+            apr_brigade_printf(ctx->bb, NULL, NULL,
+                               "%sFingerprint: %s\n",
+                               ctx->prefix,
+                               fingerprint);
+        }
+    }
+    return 1;
+}
+
+static void si_val_remote_check(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    (void)info;
+    if (ctx->mc->cert_check_name && ctx->mc->cert_check_url) {
+        const char *prefix = ctx->prefix;
+        if (!HTML_STATUS(ctx)) {
+            ctx->prefix = apr_pstrcat(ctx->p, prefix, info->label, NULL);
+        }
+        md_json_iterkey(cert_check_iter, ctx, mdj, MD_KEY_CERT, NULL);
+        if (!HTML_STATUS(ctx)) {
+            ctx->prefix = prefix;
+        }
+    }
+}
+
+static void si_val_stapling(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    (void)info;
+    if (!md_json_getb(mdj, MD_KEY_STAPLING, NULL)) return;
+    if (HTML_STATUS(ctx)) {
+        apr_brigade_puts(ctx->bb, NULL, NULL, "on");
+    }
+    else {
+        apr_brigade_printf(ctx->bb, NULL, NULL, "%s: on", ctx->prefix);
+    }
+}
+
+static int json_iter_val(void *data, size_t index, md_json_t *json)
+{
+    status_ctx *ctx = data;
+    const char *prefix = ctx->prefix;
+    if (HTML_STATUS(ctx)) {
+        if (index) apr_brigade_puts(ctx->bb, NULL, NULL, ctx->separator);
+    }
+    else {
+        ctx->prefix = apr_pstrcat(ctx->p, prefix, apr_psprintf(ctx->p, "[%" APR_SIZE_T_FMT "]", index), NULL);
+    }
+    add_json_val(ctx, json);
+    if (!HTML_STATUS(ctx)) {
+        ctx->prefix = prefix;
+    }
+    return 1;
+}
+
+static void add_json_val(status_ctx *ctx, md_json_t *j)
+{
+    if (!j) return;
+    if (md_json_is(MD_JSON_TYPE_ARRAY, j, NULL)) {
+        md_json_itera(json_iter_val, ctx, j, NULL);
+        return;
+    }
+    if (!HTML_STATUS(ctx)) {
+        apr_brigade_puts(ctx->bb, NULL, NULL, ctx->prefix);
+        apr_brigade_puts(ctx->bb, NULL, NULL, ": ");
+    }
+    if (md_json_is(MD_JSON_TYPE_INT, j, NULL)) {
+        md_json_writeb(j, MD_JSON_FMT_COMPACT, ctx->bb);
+    }
+    else if (md_json_is(MD_JSON_TYPE_STRING, j, NULL)) {
+        apr_brigade_puts(ctx->bb, NULL, NULL, md_json_gets(j, NULL));
+    }
+    else if (md_json_is(MD_JSON_TYPE_OBJECT, j, NULL)) {
+        md_json_writeb(j, MD_JSON_FMT_COMPACT, ctx->bb);
+    }
+    else if (md_json_is(MD_JSON_TYPE_BOOL, j, NULL)) {
+        apr_brigade_puts(ctx->bb, NULL, NULL, md_json_getb(j, NULL)? "on" : "off");
+    }
+    if (!HTML_STATUS(ctx)) {
+        apr_brigade_puts(ctx->bb, NULL, NULL, "\n");
+    }
+}
+
+static void si_val_names(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    const char *prefix = ctx->prefix;
+    if (HTML_STATUS(ctx)) {
+        apr_brigade_puts(ctx->bb, NULL, NULL, "<div style=\"max-width:400px;\">");
+    }
+    else {
+        ctx->prefix = apr_pstrcat(ctx->p, prefix, info->label, NULL);
+    }
+    add_json_val(ctx, md_json_getj(mdj, info->key, NULL));
+    if (HTML_STATUS(ctx)) {
+        apr_brigade_puts(ctx->bb, NULL, NULL, "</div>");
+    }
+    else {
+        ctx->prefix = prefix;
+    }
+}
+
+static void add_status_cell(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    if (info->fn) {
+        info->fn(ctx, mdj, info);
+    }
+    else {
+        const char *prefix = ctx->prefix;
+        if (!HTML_STATUS(ctx)) {
+            ctx->prefix = apr_pstrcat(ctx->p, prefix, info->label, NULL);
+        }
+        add_json_val(ctx, md_json_getj(mdj, info->key, NULL));
+        if (!HTML_STATUS(ctx)) {
+            ctx->prefix = prefix;
+        }
+    }
+}
+
+static const status_info status_infos[] = {
+    { "Domain", MD_KEY_NAME, NULL },
+    { "Names", MD_KEY_DOMAINS, si_val_names },
+    { "Status", MD_KEY_STATE, si_val_status },
+    { "Valid", MD_KEY_CERT, si_val_cert_valid_time },
+    { "CA", MD_KEY_CA, si_val_ca_urls },
+    { "Stapling", MD_KEY_STAPLING, si_val_stapling },
+    { "CheckAt", MD_KEY_SHA256_FINGERPRINT, si_val_remote_check },
+    { "Activity", MD_KEY_NOTIFIED, si_val_activity },
+};
+
+static int add_md_row(void *baton, apr_size_t index, md_json_t *mdj)
+{
+    status_ctx *ctx = baton;
+    const char *prefix = ctx->prefix;
+    int i;
+
+    if (HTML_STATUS(ctx)) {
+        apr_brigade_printf(ctx->bb, NULL, NULL, "<tr class=\"%s\">", (index % 2)? "odd" : "even");
+        for (i = 0; i < (int)(sizeof(status_infos)/sizeof(status_infos[0])); ++i) {
+            apr_brigade_puts(ctx->bb, NULL, NULL, "<td>");
+            add_status_cell(ctx, mdj, &status_infos[i]);
+            apr_brigade_puts(ctx->bb, NULL, NULL, "</td>");
+        }
+        apr_brigade_puts(ctx->bb, NULL, NULL, "</tr>");
+    } else {
+        for (i = 0; i < (int)(sizeof(status_infos)/sizeof(status_infos[0])); ++i) {
+            ctx->prefix = apr_pstrcat(ctx->p, prefix, apr_psprintf(ctx->p, "[%" APR_SIZE_T_FMT "]", index), NULL);
+            add_status_cell(ctx, mdj, &status_infos[i]);
+            ctx->prefix = prefix;
+        }
+    }
+    return 1;
+}
+
+static int md_name_cmp(const void *v1, const void *v2)
+{
+    return strcmp((*(const md_t**)v1)->name, (*(const md_t**)v2)->name);
+}
+
+int md_domains_status_hook(request_rec *r, int flags)
+{
+    const md_srv_conf_t *sc;
+    const md_mod_conf_t *mc;
+    int i;
+    status_ctx ctx;
+    apr_array_header_t *mds;
+    md_json_t *jstatus, *jstock;
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "server-status for managed domains, start");
+    sc = ap_get_module_config(r->server->module_config, &md_module);
+    if (!sc) return DECLINED;
+    mc = sc->mc;
+    if (!mc || !mc->server_status_enabled) return DECLINED;
+
+    ctx.p = r->pool;
+    ctx.mc = mc;
+    ctx.bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
+    ctx.flags = flags;
+    ctx.prefix = "ManagedCertificates";
+    ctx.separator = " ";
+
+    mds = apr_array_copy(r->pool, mc->mds);
+    qsort(mds->elts, (size_t)mds->nelts, sizeof(md_t *), md_name_cmp);
+
+    if (!HTML_STATUS(&ctx)) {
+        int total = 0, complete = 0, renewing = 0, errored = 0, ready = 0;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "no-html managed domain status summary");
+        if (mc->mds->nelts > 0) {
+            md_status_take_stock(&jstock, mds, mc->reg, r->pool);
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "got JSON managed domain status summary");
+            total = (int)md_json_getl(jstock, MD_KEY_TOTAL, NULL);
+            complete = (int)md_json_getl(jstock, MD_KEY_COMPLETE, NULL);
+            renewing = (int)md_json_getl(jstock, MD_KEY_RENEWING, NULL);
+            errored = (int)md_json_getl(jstock, MD_KEY_ERRORED, NULL);
+            ready = (int)md_json_getl(jstock, MD_KEY_READY, NULL);
+        }
+        apr_brigade_printf(ctx.bb, NULL, NULL, "%sTotal: %d\n", ctx.prefix, total);
+        apr_brigade_printf(ctx.bb, NULL, NULL, "%sOK: %d\n", ctx.prefix, complete);
+        apr_brigade_printf(ctx.bb, NULL, NULL, "%sRenew: %d\n", ctx.prefix, renewing);
+        apr_brigade_printf(ctx.bb, NULL, NULL, "%sErrored: %d\n", ctx.prefix, errored);
+        apr_brigade_printf(ctx.bb, NULL, NULL, "%sReady: %d\n", ctx.prefix, ready);
+    }
+    if (mc->mds->nelts > 0) {
+        md_status_get_json(&jstatus, mds, mc->reg, mc->ocsp, r->pool);
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "got JSON managed domain status");
+        if (HTML_STATUS(&ctx)) {
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "html managed domain status table");
+            apr_brigade_puts(ctx.bb, NULL, NULL,
+                             "<hr>\n<h3>Managed Certificates</h3>\n<table class='md_status'><thead><tr>\n");
+            for (i = 0; i < (int)(sizeof(status_infos)/sizeof(status_infos[0])); ++i) {
+                si_add_header(&ctx, &status_infos[i]);
+            }
+            apr_brigade_puts(ctx.bb, NULL, NULL, "</tr>\n</thead><tbody>");
+        }
+        else {
+            ctx.prefix = "ManagedDomain";
+        }
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "iterating JSON managed domain status");
+        md_json_itera(add_md_row, &ctx, jstatus, MD_KEY_MDS, NULL);
+        if (HTML_STATUS(&ctx)) {
+            apr_brigade_puts(ctx.bb, NULL, NULL, "</td></tr>\n</tbody>\n</table>\n");
+        }
+    }
+
+    ap_pass_brigade(r->output_filters, ctx.bb);
+    apr_brigade_cleanup(ctx.bb);
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "server-status for managed domains, end");
+
+    return OK;
+}
+
+static void si_val_ocsp_activity(status_ctx *ctx, md_json_t *mdj, const status_info *info)
+{
+    apr_time_t t;
+    const char *prefix = ctx->prefix;
+
+    (void)info;
+    if (!HTML_STATUS(ctx)) {
+        ctx->prefix = apr_pstrcat(ctx->p, prefix, info->label, NULL);
+    }
+    t = md_json_get_time(mdj, MD_KEY_RENEW_AT, NULL);
+    print_time(ctx, "Refresh", t);
+    print_job_summary(ctx, mdj, MD_KEY_RENEWAL, ": ");
+    if (!HTML_STATUS(ctx)) {
+        ctx->prefix = prefix;
+    }
+}
+
+static const status_info ocsp_status_infos[] = {
+    { "Domain", MD_KEY_DOMAIN, NULL },
+    { "CertificateID", MD_KEY_ID, NULL },
+    { "OCSPStatus", MD_KEY_STATUS, NULL },
+    { "StaplingValid", MD_KEY_VALID, si_val_valid_time },
+    { "Responder", MD_KEY_URL, si_val_url },
+    { "Activity", MD_KEY_NOTIFIED, si_val_ocsp_activity },
+};
+
+static int add_ocsp_row(void *baton, apr_size_t index, md_json_t *mdj)
+{
+    status_ctx *ctx = baton;
+    const char *prefix = ctx->prefix;
+    int i;
+
+    if (HTML_STATUS(ctx)) {
+        apr_brigade_printf(ctx->bb, NULL, NULL, "<tr class=\"%s\">", (index % 2)? "odd" : "even");
+        for (i = 0; i < (int)(sizeof(ocsp_status_infos)/sizeof(ocsp_status_infos[0])); ++i) {
+            apr_brigade_puts(ctx->bb, NULL, NULL, "<td>");
+            add_status_cell(ctx, mdj, &ocsp_status_infos[i]);
+            apr_brigade_puts(ctx->bb, NULL, NULL, "</td>");
+        }
+        apr_brigade_puts(ctx->bb, NULL, NULL, "</tr>");
+    } else {
+        for (i = 0; i < (int)(sizeof(ocsp_status_infos)/sizeof(ocsp_status_infos[0])); ++i) {
+            ctx->prefix = apr_pstrcat(ctx->p, prefix, apr_psprintf(ctx->p, "[%" APR_SIZE_T_FMT "]", index), NULL);
+            add_status_cell(ctx, mdj, &ocsp_status_infos[i]);
+            ctx->prefix = prefix;
+        }
+    }
+    return 1;
+}
+
+int md_ocsp_status_hook(request_rec *r, int flags)
+{
+    const md_srv_conf_t *sc;
+    const md_mod_conf_t *mc;
+    int i;
+    status_ctx ctx;
+    md_json_t *jstatus, *jstock;
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "server-status for ocsp stapling, start");
+    sc = ap_get_module_config(r->server->module_config, &md_module);
+    if (!sc) return DECLINED;
+    mc = sc->mc;
+    if (!mc || !mc->server_status_enabled) return DECLINED;
+
+    ctx.p = r->pool;
+    ctx.mc = mc;
+    ctx.bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
+    ctx.flags = flags;
+    ctx.prefix = "ManagedStaplings";
+    ctx.separator = " ";
+
+    if (!HTML_STATUS(&ctx)) {
+        int total = 0, good = 0, revoked = 0, unknown = 0;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "no-html ocsp stapling status summary");
+        if (md_ocsp_count(mc->ocsp) > 0) {
+            md_ocsp_get_summary(&jstock, mc->ocsp, r->pool);
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "got JSON ocsp stapling status summary");
+            total = (int)md_json_getl(jstock, MD_KEY_TOTAL, NULL);
+            good = (int)md_json_getl(jstock, MD_KEY_GOOD, NULL);
+            revoked = (int)md_json_getl(jstock, MD_KEY_REVOKED, NULL);
+            unknown = (int)md_json_getl(jstock, MD_KEY_UNKNOWN, NULL);
+        }
+        apr_brigade_printf(ctx.bb, NULL, NULL, "%sTotal: %d\n", ctx.prefix, total);
+        apr_brigade_printf(ctx.bb, NULL, NULL, "%sOK: %d\n", ctx.prefix, good);
+        apr_brigade_printf(ctx.bb, NULL, NULL, "%sRenew: %d\n", ctx.prefix, revoked);
+        apr_brigade_printf(ctx.bb, NULL, NULL, "%sErrored: %d\n", ctx.prefix, unknown);
+    }
+    if (md_ocsp_count(mc->ocsp) > 0) {
+        md_ocsp_get_status_all(&jstatus, mc->ocsp, r->pool);
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "got JSON ocsp stapling status");
+        if (HTML_STATUS(&ctx)) {
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "html ocsp stapling status table");
+            apr_brigade_puts(ctx.bb, NULL, NULL,
+                             "<hr>\n<h3>Managed Staplings</h3>\n<table class='md_ocsp_status'><thead><tr>\n");
+            for (i = 0; i < (int)(sizeof(ocsp_status_infos)/sizeof(ocsp_status_infos[0])); ++i) {
+                si_add_header(&ctx, &ocsp_status_infos[i]);
+            }
+            apr_brigade_puts(ctx.bb, NULL, NULL, "</tr>\n</thead><tbody>");
+        }
+        else {
+            ctx.prefix = "ManagedStapling";
+        }
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "iterating JSON ocsp stapling status");
+        md_json_itera(add_ocsp_row, &ctx, jstatus, MD_KEY_OCSPS, NULL);
+        if (HTML_STATUS(&ctx)) {
+            apr_brigade_puts(ctx.bb, NULL, NULL, "</td></tr>\n</tbody>\n</table>\n");
+        }
+    }
+
+    ap_pass_brigade(r->output_filters, ctx.bb);
+    apr_brigade_cleanup(ctx.bb);
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "server-status for ocsp stapling, end");
+
+    return OK;
+}
+
+/**************************************************************************************************/
+/* Status handlers */
+
+int md_status_handler(request_rec *r)
+{
+    const md_srv_conf_t *sc;
+    const md_mod_conf_t *mc;
+    apr_array_header_t *mds;
+    md_json_t *jstatus;
+    apr_bucket_brigade *bb;
+    const md_t *md;
+    const char *name;
+
+    if (strcmp(r->handler, "md-status")) {
+        return DECLINED;
+    }
+
+    sc = ap_get_module_config(r->server->module_config, &md_module);
+    if (!sc) return DECLINED;
+    mc = sc->mc;
+    if (!mc) return DECLINED;
+
+    if (r->method_number != M_GET) {
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "md-status supports only GET");
+        return HTTP_NOT_IMPLEMENTED;
+    }
+
+    jstatus = NULL;
+    md = NULL;
+    if (r->path_info && r->path_info[0] == '/' && r->path_info[1] != '\0') {
+        name = strrchr(r->path_info, '/') + 1;
+        md = md_get_by_name(mc->mds, name);
+        if (!md) md = md_get_by_domain(mc->mds, name);
+    }
+
+    if (md) {
+        md_status_get_md_json(&jstatus, md, mc->reg, mc->ocsp, r->pool);
+    }
+    else {
+        mds = apr_array_copy(r->pool, mc->mds);
+        qsort(mds->elts, (size_t)mds->nelts, sizeof(md_t *), md_name_cmp);
+        md_status_get_json(&jstatus, mds, mc->reg, mc->ocsp, r->pool);
+    }
+
+    if (jstatus) {
+        apr_table_set(r->headers_out, "Content-Type", "application/json");
+        bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
+        md_json_writeb(jstatus, MD_JSON_FMT_INDENT, bb);
+        ap_pass_brigade(r->output_filters, bb);
+        apr_brigade_cleanup(bb);
+
+        return DONE;
+    }
+    return DECLINED;
+}
+
diff --git a/modules/md/mod_md_status.h b/modules/md/mod_md_status.h
new file mode 100644
index 0000000..f347826
--- /dev/null
+++ b/modules/md/mod_md_status.h
@@ -0,0 +1,27 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef mod_md_md_status_h
+#define mod_md_md_status_h
+
+int md_http_cert_status(request_rec *r);
+
+int md_domains_status_hook(request_rec *r, int flags);
+int md_ocsp_status_hook(request_rec *r, int flags);
+
+int md_status_handler(request_rec *r);
+
+#endif /* mod_md_md_status_h */