Adding upstream version 2.4.56.upstream/2.4.56

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

1 files changed, 2140 insertions, 0 deletions

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;
+}