Adding upstream version 2.4.38.upstream/2.4.38upstream

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

1 files changed, 3221 insertions, 0 deletions

diff --git a/modules/ldap/util_ldap.c b/modules/ldap/util_ldap.c
new file mode 100644
index 0000000..08f986c
--- /dev/null
+++ b/modules/ldap/util_ldap.c
@@ -0,0 +1,3221 @@
+/* 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.
+ */
+
+/*
+ * util_ldap.c: LDAP things
+ *
+ * Original code from auth_ldap module for Apache v1.3:
+ * Copyright 1998, 1999 Enbridge Pipelines Inc.
+ * Copyright 1999-2001 Dave Carrigan
+ */
+
+#include "httpd.h"
+#include "http_config.h"
+#include "http_core.h"
+#include "http_log.h"
+#include "http_protocol.h"
+#include "http_request.h"
+#include "util_mutex.h"
+#include "util_ldap.h"
+#include "util_ldap_cache.h"
+
+#include <apr_strings.h>
+
+#if APR_HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#if !APR_HAS_LDAP
+#error mod_ldap requires APR-util to have LDAP support built in
+#endif
+
+/* Default define for ldap functions that need a SIZELIMIT but
+ * do not have the define
+ * XXX This should be removed once a supporting #define is
+ *  released through APR-Util.
+ */
+#ifndef APR_LDAP_SIZELIMIT
+#define APR_LDAP_SIZELIMIT -1
+#endif
+
+#ifdef LDAP_OPT_DEBUG_LEVEL
+#define AP_LDAP_OPT_DEBUG LDAP_OPT_DEBUG_LEVEL
+#else
+#ifdef LDAP_OPT_DEBUG
+#define AP_LDAP_OPT_DEBUG LDAP_OPT_DEBUG
+#endif
+#endif
+
+#define AP_LDAP_HOPLIMIT_UNSET -1
+#define AP_LDAP_CHASEREFERRALS_SDKDEFAULT -1
+#define AP_LDAP_CHASEREFERRALS_OFF 0
+#define AP_LDAP_CHASEREFERRALS_ON 1
+
+#define AP_LDAP_CONNPOOL_DEFAULT -1
+#define AP_LDAP_CONNPOOL_INFINITE -2
+
+#if !defined(LDAP_OPT_NETWORK_TIMEOUT) && defined(LDAP_OPT_CONNECT_TIMEOUT)
+#define LDAP_OPT_NETWORK_TIMEOUT LDAP_OPT_CONNECT_TIMEOUT
+#endif
+
+module AP_MODULE_DECLARE_DATA ldap_module;
+static const char *ldap_cache_mutex_type = "ldap-cache";
+static apr_status_t uldap_connection_unbind(void *param);
+
+#define LDAP_CACHE_LOCK() do {                                  \
+    if (st->util_ldap_cache_lock)                               \
+        apr_global_mutex_lock(st->util_ldap_cache_lock);        \
+} while (0)
+
+#define LDAP_CACHE_UNLOCK() do {                                \
+    if (st->util_ldap_cache_lock)                               \
+        apr_global_mutex_unlock(st->util_ldap_cache_lock);      \
+} while (0)
+
+static void util_ldap_strdup (char **str, const char *newstr)
+{
+    if (*str) {
+        free(*str);
+        *str = NULL;
+    }
+
+    if (newstr) {
+        *str = strdup(newstr);
+    }
+}
+
+/*
+ * Status Handler
+ * --------------
+ *
+ * This handler generates a status page about the current performance of
+ * the LDAP cache. It is enabled as follows:
+ *
+ * <Location /ldap-status>
+ *   SetHandler ldap-status
+ * </Location>
+ *
+ */
+static int util_ldap_handler(request_rec *r)
+{
+    util_ldap_state_t *st;
+
+    r->allowed |= (1 << M_GET);
+    if (r->method_number != M_GET) {
+        return DECLINED;
+    }
+
+    if (strcmp(r->handler, "ldap-status")) {
+        return DECLINED;
+    }
+
+    st = (util_ldap_state_t *) ap_get_module_config(r->server->module_config,
+            &ldap_module);
+
+    ap_set_content_type(r, "text/html; charset=ISO-8859-1");
+
+    if (r->header_only)
+        return OK;
+
+    ap_rputs(DOCTYPE_HTML_3_2
+             "<html><head><title>LDAP Cache Information</title></head>\n", r);
+    ap_rputs("<body bgcolor='#ffffff'><h1 align=center>LDAP Cache Information"
+             "</h1>\n", r);
+
+    util_ald_cache_display(r, st);
+
+    return OK;
+}
+
+
+
+/* ------------------------------------------------------------------ */
+/*
+ * Closes an LDAP connection by unlocking it. The next time
+ * uldap_connection_find() is called this connection will be
+ * available for reuse.
+ */
+static void uldap_connection_close(util_ldap_connection_t *ldc)
+{
+
+     /* We leave bound LDAP connections floating around in our pool,
+      * but always check/fix the binddn/bindpw when we take them out
+      * of the pool
+      */
+     if (!ldc->keep) {
+         uldap_connection_unbind(ldc);
+         ldc->r = NULL;
+     }
+     else {
+         /* mark our connection as available for reuse */
+         ldc->freed = apr_time_now();
+         ldc->r = NULL;
+     }
+
+#if APR_HAS_THREADS
+     apr_thread_mutex_unlock(ldc->lock);
+#endif
+}
+
+
+/*
+ * Destroys an LDAP connection by unbinding and closing the connection to
+ * the LDAP server. It is used to bring the connection back to a known
+ * state after an error.
+ */
+static apr_status_t uldap_connection_unbind(void *param)
+{
+    util_ldap_connection_t *ldc = param;
+
+    if (ldc) {
+        if (ldc->ldap) {
+            if (ldc->r) { 
+                ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, ldc->r, "LDC %pp unbind", ldc); 
+            }
+            ldap_unbind_s(ldc->ldap);
+            ldc->ldap = NULL;
+        }
+        ldc->bound = 0;
+
+        /* forget the rebind info for this conn */
+        if (ldc->ChaseReferrals == AP_LDAP_CHASEREFERRALS_ON) {
+            apr_ldap_rebind_remove(ldc->ldap);
+            apr_pool_clear(ldc->rebind_pool);
+        }
+    }
+
+    return APR_SUCCESS;
+}
+
+/* not presently used, not part of the API */
+#if 0
+/*
+ * util_ldap_connection_remove frees all storage associated with the LDAP
+ * connection and removes it completely from the per-virtualhost list of
+ * connections
+ *
+ * The caller should hold the lock for this connection
+ */
+static apr_status_t util_ldap_connection_remove (void *param)
+{
+    util_ldap_connection_t *ldc = param, *l = NULL, *prev = NULL;
+    util_ldap_state_t *st;
+
+    if (!ldc) return APR_SUCCESS;
+
+    st = ldc->st;
+
+    uldap_connection_unbind(ldc);
+
+#if APR_HAS_THREADS
+    apr_thread_mutex_lock(st->mutex);
+#endif
+
+    /* Remove ldc from the list */
+    for (l=st->connections; l; l=l->next) {
+        if (l == ldc) {
+            if (prev) {
+                prev->next = l->next;
+            }
+            else {
+                st->connections = l->next;
+            }
+            break;
+        }
+        prev = l;
+    }
+
+    if (ldc->bindpw) {
+        free((void*)ldc->bindpw);
+    }
+    if (ldc->binddn) {
+        free((void*)ldc->binddn);
+    }
+
+#if APR_HAS_THREADS
+    apr_thread_mutex_unlock(ldc->lock);
+    apr_thread_mutex_unlock(st->mutex);
+#endif
+
+    /* Destory the pool associated with this connection */
+
+    apr_pool_destroy(ldc->pool);
+
+    return APR_SUCCESS;
+}
+#endif
+
+static int uldap_connection_init(request_rec *r,
+                                 util_ldap_connection_t *ldc)
+{
+    int rc = 0, ldap_option = 0;
+    int version  = LDAP_VERSION3;
+    apr_ldap_err_t *result = NULL;
+#ifdef LDAP_OPT_NETWORK_TIMEOUT
+    struct timeval connectionTimeout = {0};
+#endif
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(r->server->module_config,
+        &ldap_module);
+    int have_client_certs = !apr_is_empty_array(ldc->client_certs);
+#if !APR_HAS_SOLARIS_LDAPSDK
+    /*
+     * Normally we enable SSL/TLS with apr_ldap_set_option(), except
+     * with Solaris LDAP, where this is broken.
+     */
+    int secure = APR_LDAP_NONE;
+#else
+    /*
+     * With Solaris LDAP, we enable TSL via the secure argument
+     * to apr_ldap_init(). This requires a fix from apr-util >= 1.4.0.
+     *
+     * Just in case client certificates ever get supported, we
+     * handle those as with the other LDAP SDKs.
+     */
+    int secure = have_client_certs ? APR_LDAP_NONE : ldc->secure;
+#endif
+
+    /* Since the host will include a port if the default port is not used,
+     * always specify the default ports for the port parameter.  This will
+     * allow a host string that contains multiple hosts the ability to mix
+     * some hosts with ports and some without. All hosts which do not
+     * specify a port will use the default port.
+     */
+    apr_ldap_init(r->pool, &(ldc->ldap),
+                  ldc->host,
+                  APR_LDAP_SSL == ldc->secure ? LDAPS_PORT : LDAP_PORT,
+                  secure, &(result));
+
+    if (NULL == result) {
+        /* something really bad happened */
+        ldc->bound = 0;
+        if (NULL == ldc->reason) {
+            ldc->reason = "LDAP: ldap initialization failed";
+        }
+        return(APR_EGENERAL);
+    }
+
+    if (result->rc) {
+        ldc->reason = result->reason;
+        ldc->bound = 0;
+        return result->rc;
+    }
+
+    if (NULL == ldc->ldap)
+    {
+        ldc->bound = 0;
+        if (NULL == ldc->reason) {
+            ldc->reason = "LDAP: ldap initialization failed";
+        }
+        else {
+            ldc->reason = result->reason;
+        }
+        return(result->rc);
+    }
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "LDC %pp init", ldc);
+
+    if (ldc->ChaseReferrals == AP_LDAP_CHASEREFERRALS_ON) {
+        /* Now that we have an ldap struct, add it to the referral list for rebinds. */
+        rc = apr_ldap_rebind_add(ldc->rebind_pool, ldc->ldap, ldc->binddn, ldc->bindpw);
+        if (rc != APR_SUCCESS) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, rc, r->server, APLOGNO(01277)
+                    "LDAP: Unable to add rebind cross reference entry. Out of memory?");
+            uldap_connection_unbind(ldc);
+            ldc->reason = "LDAP: Unable to add rebind cross reference entry.";
+            return(rc);
+        }
+    }
+
+    /* always default to LDAP V3 */
+    ldap_set_option(ldc->ldap, LDAP_OPT_PROTOCOL_VERSION, &version);
+
+    /* set client certificates */
+    if (have_client_certs) {
+        apr_ldap_set_option(r->pool, ldc->ldap, APR_LDAP_OPT_TLS_CERT,
+                            ldc->client_certs, &(result));
+        if (LDAP_SUCCESS != result->rc) {
+            uldap_connection_unbind( ldc );
+            ldc->reason = result->reason;
+            return(result->rc);
+        }
+    }
+
+    /* switch on SSL/TLS */
+    if (APR_LDAP_NONE != ldc->secure
+#if APR_HAS_SOLARIS_LDAPSDK
+        /* See comments near apr_ldap_init() above */
+        && have_client_certs
+#endif
+       ) {
+        apr_ldap_set_option(r->pool, ldc->ldap,
+                            APR_LDAP_OPT_TLS, &ldc->secure, &(result));
+        if (LDAP_SUCCESS != result->rc) {
+            uldap_connection_unbind( ldc );
+            ldc->reason = result->reason;
+            return(result->rc);
+        }
+    }
+
+    /* Set the alias dereferencing option */
+    ldap_option = ldc->deref;
+    ldap_set_option(ldc->ldap, LDAP_OPT_DEREF, &ldap_option);
+
+    if (ldc->ChaseReferrals != AP_LDAP_CHASEREFERRALS_SDKDEFAULT) {
+        /* Set options for rebind and referrals. */
+        ap_log_error(APLOG_MARK, APLOG_TRACE4, 0, r->server, APLOGNO(01278)
+                "LDAP: Setting referrals to %s.",
+                ((ldc->ChaseReferrals == AP_LDAP_CHASEREFERRALS_ON) ? "On" : "Off"));
+        apr_ldap_set_option(r->pool, ldc->ldap,
+                APR_LDAP_OPT_REFERRALS,
+                (void *)((ldc->ChaseReferrals == AP_LDAP_CHASEREFERRALS_ON) ?
+                    LDAP_OPT_ON : LDAP_OPT_OFF),
+                &(result));
+        if (result->rc != LDAP_SUCCESS) {
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, APLOGNO(01279)
+                    "Unable to set LDAP_OPT_REFERRALS option to %s: %d.",
+                    ((ldc->ChaseReferrals == AP_LDAP_CHASEREFERRALS_ON) ? "On" : "Off"),
+                    result->rc);
+            result->reason = "Unable to set LDAP_OPT_REFERRALS.";
+            ldc->reason = result->reason;
+            uldap_connection_unbind(ldc);
+            return(result->rc);
+        }
+    }
+
+    if (ldc->ChaseReferrals == AP_LDAP_CHASEREFERRALS_ON) {
+        if ((ldc->ReferralHopLimit != AP_LDAP_HOPLIMIT_UNSET) && ldc->ChaseReferrals == AP_LDAP_CHASEREFERRALS_ON) {
+            /* Referral hop limit - only if referrals are enabled and a hop limit is explicitly requested */
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, APLOGNO(01280)
+                    "Setting referral hop limit to %d.",
+                    ldc->ReferralHopLimit);
+            apr_ldap_set_option(r->pool, ldc->ldap,
+                    APR_LDAP_OPT_REFHOPLIMIT,
+                    (void *)&ldc->ReferralHopLimit,
+                    &(result));
+            if (result->rc != LDAP_SUCCESS) {
+                ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, APLOGNO(01281)
+                        "Unable to set LDAP_OPT_REFHOPLIMIT option to %d: %d.",
+                        ldc->ReferralHopLimit,
+                        result->rc);
+                result->reason = "Unable to set LDAP_OPT_REFHOPLIMIT.";
+                ldc->reason = result->reason;
+                uldap_connection_unbind(ldc);
+                return(result->rc);
+            }
+        }
+    }
+
+/*XXX All of the #ifdef's need to be removed once apr-util 1.2 is released */
+#ifdef APR_LDAP_OPT_VERIFY_CERT
+    apr_ldap_set_option(r->pool, ldc->ldap, APR_LDAP_OPT_VERIFY_CERT,
+                        &(st->verify_svr_cert), &(result));
+#else
+#if defined(LDAPSSL_VERIFY_SERVER)
+    if (st->verify_svr_cert) {
+        result->rc = ldapssl_set_verify_mode(LDAPSSL_VERIFY_SERVER);
+    }
+    else {
+        result->rc = ldapssl_set_verify_mode(LDAPSSL_VERIFY_NONE);
+    }
+#elif defined(LDAP_OPT_X_TLS_REQUIRE_CERT)
+    /* This is not a per-connection setting so just pass NULL for the
+       Ldap connection handle */
+    if (st->verify_svr_cert) {
+        int i = LDAP_OPT_X_TLS_DEMAND;
+        result->rc = ldap_set_option(NULL, LDAP_OPT_X_TLS_REQUIRE_CERT, &i);
+    }
+    else {
+        int i = LDAP_OPT_X_TLS_NEVER;
+        result->rc = ldap_set_option(NULL, LDAP_OPT_X_TLS_REQUIRE_CERT, &i);
+    }
+#endif
+#endif
+
+#ifdef LDAP_OPT_NETWORK_TIMEOUT
+    if (st->connectionTimeout > 0) {
+        connectionTimeout.tv_sec = st->connectionTimeout;
+    }
+
+    if (connectionTimeout.tv_sec > 0) {
+        rc = apr_ldap_set_option(r->pool, ldc->ldap, LDAP_OPT_NETWORK_TIMEOUT,
+                                 (void *)&connectionTimeout, &(result));
+        if (APR_SUCCESS != rc) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, APLOGNO(01282)
+                             "LDAP: Could not set the connection timeout");
+        }
+    }
+#endif
+
+#ifdef LDAP_OPT_TIMEOUT
+    /*
+     * LDAP_OPT_TIMEOUT is not portable, but it influences all synchronous ldap
+     * function calls and not just ldap_search_ext_s(), which accepts a timeout
+     * parameter.
+     * XXX: It would be possible to simulate LDAP_OPT_TIMEOUT by replacing all
+     * XXX: synchronous ldap function calls with asynchronous calls and using
+     * XXX: ldap_result() with a timeout.
+     */
+    if (st->opTimeout) {
+        rc = apr_ldap_set_option(r->pool, ldc->ldap, LDAP_OPT_TIMEOUT,
+                                 st->opTimeout, &(result));
+        if (APR_SUCCESS != rc) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, APLOGNO(01283)
+                             "LDAP: Could not set LDAP_OPT_TIMEOUT");
+        }
+    }
+#endif
+
+    return(rc);
+}
+
+static int uldap_ld_errno(util_ldap_connection_t *ldc)
+{
+    int ldaprc;
+#ifdef LDAP_OPT_ERROR_NUMBER
+    if (LDAP_SUCCESS == ldap_get_option(ldc->ldap, LDAP_OPT_ERROR_NUMBER, &ldaprc)) return ldaprc;
+#endif
+#ifdef LDAP_OPT_RESULT_CODE
+    if (LDAP_SUCCESS == ldap_get_option(ldc->ldap, LDAP_OPT_RESULT_CODE, &ldaprc)) return ldaprc;
+#endif
+    return LDAP_OTHER;
+}
+
+/*
+ * Replacement function for ldap_simple_bind_s() with a timeout.
+ * To do this in a portable way, we have to use ldap_simple_bind() and
+ * ldap_result().
+ *
+ * Returns LDAP_SUCCESS on success; and an error code on failure
+ */
+static int uldap_simple_bind(util_ldap_connection_t *ldc, char *binddn,
+                             char* bindpw, struct timeval *timeout)
+{
+    LDAPMessage *result;
+    int rc;
+    int msgid = ldap_simple_bind(ldc->ldap, binddn, bindpw);
+    if (msgid == -1) {
+        ldc->reason = "LDAP: ldap_simple_bind() failed";
+        return uldap_ld_errno(ldc);
+    }
+    rc = ldap_result(ldc->ldap, msgid, 0, timeout, &result);
+    if (rc == -1) {
+        ldc->reason = "LDAP: ldap_simple_bind() result retrieval failed";
+        /* -1 is LDAP_SERVER_DOWN in openldap, use something else */
+        return uldap_ld_errno(ldc);
+    }
+    else if (rc == 0) {
+        ldc->reason = "LDAP: ldap_simple_bind() timed out";
+        rc = LDAP_TIMEOUT;
+    } else if (ldap_parse_result(ldc->ldap, result, &rc, NULL, NULL, NULL,
+                                 NULL, 1) == -1) {
+        ldc->reason = "LDAP: ldap_simple_bind() parse result failed";
+        return uldap_ld_errno(ldc);
+    }
+    else { 
+        ldc->last_backend_conn = ldc->r->request_time;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, ldc->r, "LDC %pp bind", ldc);
+    }
+    return rc;
+}
+
+/*
+ * Connect to the LDAP server and binds. Does not connect if already
+ * connected (i.e. ldc->ldap is non-NULL.) Does not bind if already bound.
+ *
+ * Returns LDAP_SUCCESS on success; and an error code on failure
+ */
+static int uldap_connection_open(request_rec *r,
+                                 util_ldap_connection_t *ldc)
+{
+    int rc = 0;
+    int failures = 0;
+    int new_connection = 0;
+    util_ldap_state_t *st;
+
+    /* sanity check for NULL */
+    if (!ldc) {
+        return -1;
+    }
+
+    /* If the connection is already bound, return
+    */
+    if (ldc->bound && !ldc->must_rebind)
+    {
+        ldc->reason = "LDAP: connection open successful (already bound)";
+        return LDAP_SUCCESS;
+    }
+
+    /* create the ldap session handle
+    */
+    if (NULL == ldc->ldap)
+    {
+       new_connection = 1;
+       rc = uldap_connection_init( r, ldc );
+       if (LDAP_SUCCESS != rc)
+       {
+           return rc;
+       }
+    }
+
+
+    st = (util_ldap_state_t *)ap_get_module_config(r->server->module_config,
+                                                   &ldap_module);
+
+    /* loop trying to bind up to st->retries times if LDAP_SERVER_DOWN or LDAP_TIMEOUT
+     * are returned.  Close the connection before the first retry, and then on every
+     * other retry.
+     *
+     * On Success or any other error, break out of the loop.
+     *
+     * NOTE: Looping is probably not a great idea. If the server isn't
+     * responding the chances it will respond after a few tries are poor.
+     * However, the original code looped and it only happens on
+     * the error condition.
+     */
+
+    while (failures <= st->retries) {
+        if (failures > 0 && st->retry_delay > 0) {
+            apr_sleep(st->retry_delay);
+        }
+        rc = uldap_simple_bind(ldc, (char *)ldc->binddn, (char *)ldc->bindpw,
+                               st->opTimeout);
+
+        if (rc == LDAP_SUCCESS) break;
+
+        failures++;
+
+        if (AP_LDAP_IS_SERVER_DOWN(rc)) {
+             ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
+                          "ldap_simple_bind() failed with server down "
+                          "(try %d)", failures);
+        }
+        else if (rc == LDAP_TIMEOUT) {
+            ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(01284)
+                          "ldap_simple_bind() timed out on %s "
+                          "connection, dropped by firewall?",
+                          new_connection ? "new" : "reused");
+        }
+        else {
+            /* Other errors not retryable */
+            break;
+        }
+
+        if (!(failures % 2)) {
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
+                          "attempt to re-init the connection");
+            uldap_connection_unbind(ldc);
+            if (LDAP_SUCCESS != uldap_connection_init(r, ldc)) {
+                /* leave rc as the initial bind return code */
+                break;
+            }
+        }
+    }
+
+    /* free the handle if there was an error
+    */
+    if (LDAP_SUCCESS != rc)
+    {
+        uldap_connection_unbind(ldc);
+        ldc->reason = "LDAP: ldap_simple_bind() failed";
+    }
+    else {
+        ldc->bound = 1;
+        ldc->must_rebind = 0;
+        ldc->reason = "LDAP: connection open successful";
+    }
+
+    return(rc);
+}
+
+
+/*
+ * Compare client certificate arrays.
+ *
+ * Returns 1 on compare failure, 0 otherwise.
+ */
+static int compare_client_certs(apr_array_header_t *srcs,
+                                apr_array_header_t *dests)
+{
+    int i = 0;
+    struct apr_ldap_opt_tls_cert_t *src, *dest;
+
+    /* arrays both NULL? if so, then equal */
+    if (srcs == NULL && dests == NULL) {
+        return 0;
+    }
+
+    /* arrays different length or either NULL? If so, then not equal */
+    if (srcs == NULL || dests == NULL || srcs->nelts != dests->nelts) {
+        return 1;
+    }
+
+    /* run an actual comparison */
+    src = (struct apr_ldap_opt_tls_cert_t *)srcs->elts;
+    dest = (struct apr_ldap_opt_tls_cert_t *)dests->elts;
+    for (i = 0; i < srcs->nelts; i++) {
+        if ((strcmp(src[i].path, dest[i].path)) ||
+            (src[i].type != dest[i].type) ||
+            /* One is passwordless? If so, then not equal */
+            ((src[i].password == NULL) ^ (dest[i].password == NULL)) ||
+            (src[i].password != NULL && dest[i].password != NULL &&
+             strcmp(src[i].password, dest[i].password))) {
+            return 1;
+        }
+    }
+
+    /* if we got here, the cert arrays were identical */
+    return 0;
+
+}
+
+
+/*
+ * Find an existing ldap connection struct that matches the
+ * provided ldap connection parameters.
+ *
+ * If not found in the cache, a new ldc structure will be allocated
+ * from st->pool and returned to the caller.  If found in the cache,
+ * a pointer to the existing ldc structure will be returned.
+ */
+static util_ldap_connection_t *
+            uldap_connection_find(request_rec *r,
+                                  const char *host, int port,
+                                  const char *binddn, const char *bindpw,
+                                  deref_options deref, int secure)
+{
+    struct util_ldap_connection_t *l, *p; /* To traverse the linked list */
+    int secureflag = secure;
+    apr_time_t now = apr_time_now();
+
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(r->server->module_config,
+        &ldap_module);
+    util_ldap_config_t *dc =
+        (util_ldap_config_t *) ap_get_module_config(r->per_dir_config, &ldap_module);
+
+#if APR_HAS_THREADS
+    /* mutex lock this function */
+    apr_thread_mutex_lock(st->mutex);
+#endif
+
+    if (secure < APR_LDAP_NONE) {
+        secureflag = st->secure;
+    }
+
+    /* Search for an exact connection match in the list that is not
+     * being used.
+     */
+    for (l=st->connections,p=NULL; l; l=l->next) {
+#if APR_HAS_THREADS
+        if (APR_SUCCESS == apr_thread_mutex_trylock(l->lock)) {
+#endif
+        if (   (l->port == port) && (strcmp(l->host, host) == 0)
+            && ((!l->binddn && !binddn) || (l->binddn && binddn
+                                             && !strcmp(l->binddn, binddn)))
+            && ((!l->bindpw && !bindpw) || (l->bindpw && bindpw
+                                             && !strcmp(l->bindpw, bindpw)))
+            && (l->deref == deref) && (l->secure == secureflag)
+            && !compare_client_certs(dc->client_certs, l->client_certs))
+        {
+            if (st->connection_pool_ttl > 0) {
+                if (l->bound && (now - l->last_backend_conn) > st->connection_pool_ttl) {
+                    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
+                                  "Removing LDAP connection last used %" APR_TIME_T_FMT " seconds ago",
+                                  (now - l->last_backend_conn) / APR_USEC_PER_SEC);
+                    l->r = r;
+                    uldap_connection_unbind(l);
+                    /* Go ahead (by falling through) and use it, so we don't create more just to unbind some other old ones */
+                }
+                ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, 
+                              "Reuse %s LDC %pp", 
+                              l->bound ? "bound" : "unbound", l);
+            }
+            break;
+        }
+#if APR_HAS_THREADS
+            /* If this connection didn't match the criteria, then we
+             * need to unlock the mutex so it is available to be reused.
+             */
+            apr_thread_mutex_unlock(l->lock);
+        }
+#endif
+        p = l;
+    }
+
+    /* If nothing found, search again, but we don't care about the
+     * binddn and bindpw this time.
+     */
+    if (!l) {
+        for (l=st->connections,p=NULL; l; l=l->next) {
+#if APR_HAS_THREADS
+            if (APR_SUCCESS == apr_thread_mutex_trylock(l->lock)) {
+
+#endif
+            if ((l->port == port) && (strcmp(l->host, host) == 0) &&
+                (l->deref == deref) && (l->secure == secureflag) &&
+                !compare_client_certs(dc->client_certs, l->client_certs))
+            {
+                if (st->connection_pool_ttl > 0) {
+                    if (l->bound && (now - l->last_backend_conn) > st->connection_pool_ttl) {
+                        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
+                                "Removing LDAP connection last used %" APR_TIME_T_FMT " seconds ago",
+                                (now - l->last_backend_conn) / APR_USEC_PER_SEC);
+                        l->r = r;
+                        uldap_connection_unbind(l);
+                        /* Go ahead (by falling through) and use it, so we don't create more just to unbind some other old ones */
+                    }
+                    ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, 
+                                  "Reuse %s LDC %pp (will rebind)", 
+                                   l->bound ? "bound" : "unbound", l);
+                }
+
+                /* the bind credentials have changed */
+                l->must_rebind = 1;
+                util_ldap_strdup((char**)&(l->binddn), binddn);
+                util_ldap_strdup((char**)&(l->bindpw), bindpw);
+
+                break;
+            }
+#if APR_HAS_THREADS
+                /* If this connection didn't match the criteria, then we
+                 * need to unlock the mutex so it is available to be reused.
+                 */
+                apr_thread_mutex_unlock(l->lock);
+            }
+#endif
+            p = l;
+        }
+    }
+
+/* artificially disable cache */
+/* l = NULL; */
+
+    /* If no connection was found after the second search, we
+     * must create one.
+     */
+    if (!l) {
+        apr_pool_t *newpool;
+        if (apr_pool_create(&newpool, NULL) != APR_SUCCESS) {
+            ap_log_rerror(APLOG_MARK, APLOG_CRIT, 0, r, APLOGNO(01285)
+                          "util_ldap: Failed to create memory pool");
+#if APR_HAS_THREADS
+            apr_thread_mutex_unlock(st->mutex);
+#endif
+            return NULL;
+        }
+
+        /*
+         * Add the new connection entry to the linked list. Note that we
+         * don't actually establish an LDAP connection yet; that happens
+         * the first time authentication is requested.
+         */
+
+        /* create the details of this connection in the new pool */
+        l = apr_pcalloc(newpool, sizeof(util_ldap_connection_t));
+        l->pool = newpool;
+        l->st = st;
+
+#if APR_HAS_THREADS
+        apr_thread_mutex_create(&l->lock, APR_THREAD_MUTEX_DEFAULT, l->pool);
+        apr_thread_mutex_lock(l->lock);
+#endif
+        l->bound = 0;
+        l->host = apr_pstrdup(l->pool, host);
+        l->port = port;
+        l->deref = deref;
+        util_ldap_strdup((char**)&(l->binddn), binddn);
+        util_ldap_strdup((char**)&(l->bindpw), bindpw);
+        l->ChaseReferrals = dc->ChaseReferrals;
+        l->ReferralHopLimit = dc->ReferralHopLimit;
+
+        /* The security mode after parsing the URL will always be either
+         * APR_LDAP_NONE (ldap://) or APR_LDAP_SSL (ldaps://).
+         * If the security setting is NONE, override it to the security
+         * setting optionally supplied by the admin using LDAPTrustedMode
+         */
+        l->secure = secureflag;
+
+        /* save away a copy of the client cert list that is presently valid */
+        l->client_certs = apr_array_copy_hdr(l->pool, dc->client_certs);
+
+        /* whether or not to keep this connection in the pool when it's returned */
+        l->keep = (st->connection_pool_ttl == 0) ? 0 : 1;
+
+        if (l->ChaseReferrals == AP_LDAP_CHASEREFERRALS_ON) {
+            if (apr_pool_create(&(l->rebind_pool), l->pool) != APR_SUCCESS) {
+                ap_log_rerror(APLOG_MARK, APLOG_CRIT, 0, r, APLOGNO(01286)
+                              "util_ldap: Failed to create memory pool");
+#if APR_HAS_THREADS
+                apr_thread_mutex_unlock(st->mutex);
+#endif
+                return NULL;
+            }
+        }
+
+        if (p) {
+            p->next = l;
+        }
+        else {
+            st->connections = l;
+        }
+    }
+
+#if APR_HAS_THREADS
+    apr_thread_mutex_unlock(st->mutex);
+#endif
+    l->r = r;
+    return l;
+}
+
+/* ------------------------------------------------------------------ */
+
+/*
+ * Compares two DNs to see if they're equal. The only way to do this correctly
+ * is to search for the dn and then do ldap_get_dn() on the result. This should
+ * match the initial dn, since it would have been also retrieved with
+ * ldap_get_dn(). This is expensive, so if the configuration value
+ * compare_dn_on_server is false, just does an ordinary strcmp.
+ *
+ * The lock for the ldap cache should already be acquired.
+ */
+static int uldap_cache_comparedn(request_rec *r, util_ldap_connection_t *ldc,
+                                 const char *url, const char *dn,
+                                 const char *reqdn, int compare_dn_on_server)
+{
+    int result = 0;
+    util_url_node_t *curl;
+    util_url_node_t curnode;
+    util_dn_compare_node_t *node;
+    util_dn_compare_node_t newnode;
+    int failures = 0;
+    LDAPMessage *res, *entry;
+    char *searchdn;
+
+    util_ldap_state_t *st = (util_ldap_state_t *)
+                            ap_get_module_config(r->server->module_config,
+                                                 &ldap_module);
+
+    /* get cache entry (or create one) */
+    LDAP_CACHE_LOCK();
+
+    curnode.url = url;
+    curl = util_ald_cache_fetch(st->util_ldap_cache, &curnode);
+    if (curl == NULL) {
+        curl = util_ald_create_caches(st, url);
+    }
+    LDAP_CACHE_UNLOCK();
+
+    /* a simple compare? */
+    if (!compare_dn_on_server) {
+        /* unlock this read lock */
+        if (strcmp(dn, reqdn)) {
+            ldc->reason = "DN Comparison FALSE (direct strcmp())";
+            return LDAP_COMPARE_FALSE;
+        }
+        else {
+            ldc->reason = "DN Comparison TRUE (direct strcmp())";
+            return LDAP_COMPARE_TRUE;
+        }
+    }
+
+    if (curl) {
+        /* no - it's a server side compare */
+        LDAP_CACHE_LOCK();
+
+        /* is it in the compare cache? */
+        newnode.reqdn = (char *)reqdn;
+        node = util_ald_cache_fetch(curl->dn_compare_cache, &newnode);
+        if (node != NULL) {
+            /* If it's in the cache, it's good */
+            /* unlock this read lock */
+            LDAP_CACHE_UNLOCK();
+            ldc->reason = "DN Comparison TRUE (cached)";
+            return LDAP_COMPARE_TRUE;
+        }
+
+        /* unlock this read lock */
+        LDAP_CACHE_UNLOCK();
+    }
+
+start_over:
+    if (failures > st->retries) {
+        return result;
+    }
+
+    if (failures > 0 && st->retry_delay > 0) {
+        apr_sleep(st->retry_delay);
+    }
+
+    /* make a server connection */
+    if (LDAP_SUCCESS != (result = uldap_connection_open(r, ldc))) {
+        /* connect to server failed */
+        return result;
+    }
+
+    /* search for reqdn */
+    result = ldap_search_ext_s(ldc->ldap, (char *)reqdn, LDAP_SCOPE_BASE,
+                               "(objectclass=*)", NULL, 1,
+                               NULL, NULL, st->opTimeout, APR_LDAP_SIZELIMIT, &res);
+    if (AP_LDAP_IS_SERVER_DOWN(result))
+    {
+        ldc->reason = "DN Comparison ldap_search_ext_s() "
+                      "failed with server down";
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+    if (result == LDAP_TIMEOUT && failures == 0) {
+        /*
+         * we are reusing a connection that doesn't seem to be active anymore
+         * (firewall state drop?), let's try a new connection.
+         */
+        ldc->reason = "DN Comparison ldap_search_ext_s() "
+                      "failed with timeout";
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+    if (result != LDAP_SUCCESS) {
+        /* search for reqdn failed - no match */
+        ldc->reason = "DN Comparison ldap_search_ext_s() failed";
+        return result;
+    }
+
+    ldc->last_backend_conn = r->request_time;
+    entry = ldap_first_entry(ldc->ldap, res);
+    searchdn = ldap_get_dn(ldc->ldap, entry);
+
+    ldap_msgfree(res);
+    if (strcmp(dn, searchdn) != 0) {
+        /* compare unsuccessful */
+        ldc->reason = "DN Comparison FALSE (checked on server)";
+        result = LDAP_COMPARE_FALSE;
+    }
+    else {
+        if (curl) {
+            /* compare successful - add to the compare cache */
+            LDAP_CACHE_LOCK();
+            newnode.reqdn = (char *)reqdn;
+            newnode.dn = (char *)dn;
+
+            node = util_ald_cache_fetch(curl->dn_compare_cache, &newnode);
+            if (   (node == NULL)
+                || (strcmp(reqdn, node->reqdn) != 0)
+                || (strcmp(dn, node->dn) != 0))
+            {
+                util_ald_cache_insert(curl->dn_compare_cache, &newnode);
+            }
+            LDAP_CACHE_UNLOCK();
+        }
+        ldc->reason = "DN Comparison TRUE (checked on server)";
+        result = LDAP_COMPARE_TRUE;
+    }
+    ldap_memfree(searchdn);
+    return result;
+
+}
+
+/*
+ * Does an generic ldap_compare operation. It accepts a cache that it will use
+ * to lookup the compare in the cache. We cache two kinds of compares
+ * (require group compares) and (require user compares). Each compare has a
+ * different cache node: require group includes the DN; require user does not
+ * because the require user cache is owned by the
+ *
+ */
+static int uldap_cache_compare(request_rec *r, util_ldap_connection_t *ldc,
+                               const char *url, const char *dn,
+                               const char *attrib, const char *value)
+{
+    int result = 0;
+    util_url_node_t *curl;
+    util_url_node_t curnode;
+    util_compare_node_t *compare_nodep;
+    util_compare_node_t the_compare_node;
+    apr_time_t curtime = 0; /* silence gcc -Wall */
+    int failures = 0;
+
+    util_ldap_state_t *st = (util_ldap_state_t *)
+                            ap_get_module_config(r->server->module_config,
+                                                 &ldap_module);
+
+    /* get cache entry (or create one) */
+    LDAP_CACHE_LOCK();
+    curnode.url = url;
+    curl = util_ald_cache_fetch(st->util_ldap_cache, &curnode);
+    if (curl == NULL) {
+        curl = util_ald_create_caches(st, url);
+    }
+    LDAP_CACHE_UNLOCK();
+
+    if (curl) {
+        /* make a comparison to the cache */
+        LDAP_CACHE_LOCK();
+        curtime = apr_time_now();
+
+        the_compare_node.dn = (char *)dn;
+        the_compare_node.attrib = (char *)attrib;
+        the_compare_node.value = (char *)value;
+        the_compare_node.result = 0;
+        the_compare_node.sgl_processed = 0;
+        the_compare_node.subgroupList = NULL;
+
+        compare_nodep = util_ald_cache_fetch(curl->compare_cache,
+                                             &the_compare_node);
+
+        if (compare_nodep != NULL) {
+            /* found it... */
+            if (curtime - compare_nodep->lastcompare > st->compare_cache_ttl) {
+                /* ...but it is too old */
+                util_ald_cache_remove(curl->compare_cache, compare_nodep);
+            }
+            else {
+                /* ...and it is good */
+                if (LDAP_COMPARE_TRUE == compare_nodep->result) {
+                    ldc->reason = "Comparison true (cached)";
+                }
+                else if (LDAP_COMPARE_FALSE == compare_nodep->result) {
+                    ldc->reason = "Comparison false (cached)";
+                }
+                else if (LDAP_NO_SUCH_ATTRIBUTE == compare_nodep->result) {
+                    ldc->reason = "Comparison no such attribute (cached)";
+                }
+                else {
+                    ldc->reason = apr_psprintf(r->pool, 
+                                              "Comparison undefined: (%d): %s (adding to cache)", 
+                                              result, ldap_err2string(result));
+                }
+
+                /* record the result code to return with the reason... */
+                result = compare_nodep->result;
+                /* and unlock this read lock */
+                LDAP_CACHE_UNLOCK();
+
+                ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, 
+                              "ldap_compare_s(%pp, %s, %s, %s) = %s (cached)", 
+                              ldc->ldap, dn, attrib, value, ldap_err2string(result));
+                return result;
+            }
+        }
+        /* unlock this read lock */
+        LDAP_CACHE_UNLOCK();
+    }
+
+start_over:
+    if (failures > st->retries) {
+        return result;
+    }
+
+    if (failures > 0 && st->retry_delay > 0) {
+        apr_sleep(st->retry_delay);
+    }
+
+    if (LDAP_SUCCESS != (result = uldap_connection_open(r, ldc))) {
+        /* connect failed */
+        return result;
+    }
+
+    result = ldap_compare_s(ldc->ldap,
+                            (char *)dn,
+                            (char *)attrib,
+                            (char *)value);
+    if (AP_LDAP_IS_SERVER_DOWN(result)) {
+        /* connection failed - try again */
+        ldc->reason = "ldap_compare_s() failed with server down";
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+    if (result == LDAP_TIMEOUT && failures == 0) {
+        /*
+         * we are reusing a connection that doesn't seem to be active anymore
+         * (firewall state drop?), let's try a new connection.
+         */
+        ldc->reason = "ldap_compare_s() failed with timeout";
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+
+    ldc->last_backend_conn = r->request_time;
+    ldc->reason = "Comparison complete";
+    if ((LDAP_COMPARE_TRUE == result) ||
+        (LDAP_COMPARE_FALSE == result) ||
+        (LDAP_NO_SUCH_ATTRIBUTE == result)) {
+        if (curl) {
+            /* compare completed; caching result */
+            LDAP_CACHE_LOCK();
+            the_compare_node.lastcompare = curtime;
+            the_compare_node.result = result;
+            the_compare_node.sgl_processed = 0;
+            the_compare_node.subgroupList = NULL;
+
+            /* If the node doesn't exist then insert it, otherwise just update
+             * it with the last results
+             */
+            compare_nodep = util_ald_cache_fetch(curl->compare_cache,
+                                                 &the_compare_node);
+            if (   (compare_nodep == NULL)
+                || (strcmp(the_compare_node.dn, compare_nodep->dn) != 0)
+                || (strcmp(the_compare_node.attrib,compare_nodep->attrib) != 0)
+                || (strcmp(the_compare_node.value, compare_nodep->value) != 0))
+            {
+                void *junk;
+
+                junk = util_ald_cache_insert(curl->compare_cache,
+                                             &the_compare_node);
+                if (junk == NULL) {
+                    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01287)
+                                  "cache_compare: Cache insertion failure.");
+                }
+            }
+            else {
+                compare_nodep->lastcompare = curtime;
+                compare_nodep->result = result;
+            }
+            LDAP_CACHE_UNLOCK();
+        }
+
+        if (LDAP_COMPARE_TRUE == result) {
+            ldc->reason = "Comparison true (adding to cache)";
+        }
+        else if (LDAP_COMPARE_FALSE == result) {
+            ldc->reason = "Comparison false (adding to cache)";
+        }
+        else if (LDAP_NO_SUCH_ATTRIBUTE == result) {
+            ldc->reason = "Comparison no such attribute (adding to cache)";
+        }
+        else {
+            ldc->reason = apr_psprintf(r->pool, 
+                                       "Comparison undefined: (%d): %s (adding to cache)", 
+                                        result, ldap_err2string(result));
+        }
+    }
+
+    ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, 
+                  "ldap_compare_s(%pp, %s, %s, %s) = %s", 
+                  ldc->ldap, dn, attrib, value, ldap_err2string(result));
+    return result;
+}
+
+
+static util_compare_subgroup_t* uldap_get_subgroups(request_rec *r,
+                                                    util_ldap_connection_t *ldc,
+                                                    const char *url,
+                                                    const char *dn,
+                                                    char **subgroupAttrs,
+                                                    apr_array_header_t *subgroupclasses)
+{
+    int failures = 0;
+    int result = LDAP_COMPARE_FALSE;
+    util_compare_subgroup_t *res = NULL;
+    LDAPMessage *sga_res, *entry;
+    struct mod_auth_ldap_groupattr_entry_t *sgc_ents;
+    apr_array_header_t *subgroups = apr_array_make(r->pool, 20, sizeof(char *));
+    util_ldap_state_t *st = (util_ldap_state_t *)
+                            ap_get_module_config(r->server->module_config,
+                                                 &ldap_module);
+
+    sgc_ents = (struct mod_auth_ldap_groupattr_entry_t *) subgroupclasses->elts;
+
+    if (!subgroupAttrs) {
+        return res;
+    }
+
+start_over:
+    /*
+     * 3.B. The cache didn't have any subgrouplist yet. Go check for subgroups.
+     */
+    if (failures > st->retries) {
+        return res;
+    }
+
+    if (failures > 0 && st->retry_delay > 0) {
+        apr_sleep(st->retry_delay);
+    }
+
+
+    if (LDAP_SUCCESS != (result = uldap_connection_open(r, ldc))) {
+        /* connect failed */
+        return res;
+    }
+
+    /* try to do the search */
+    result = ldap_search_ext_s(ldc->ldap, (char *)dn, LDAP_SCOPE_BASE,
+                               NULL, subgroupAttrs, 0,
+                               NULL, NULL, NULL, APR_LDAP_SIZELIMIT, &sga_res);
+    if (AP_LDAP_IS_SERVER_DOWN(result)) {
+        ldc->reason = "ldap_search_ext_s() for subgroups failed with server"
+                      " down";
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+    if (result == LDAP_TIMEOUT && failures == 0) {
+        /*
+         * we are reusing a connection that doesn't seem to be active anymore
+         * (firewall state drop?), let's try a new connection.
+         */
+        ldc->reason = "ldap_search_ext_s() for subgroups failed with timeout";
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+
+    /* if there is an error (including LDAP_NO_SUCH_OBJECT) return now */
+    if (result != LDAP_SUCCESS) {
+        ldc->reason = "ldap_search_ext_s() for subgroups failed";
+        return res;
+    }
+
+    ldc->last_backend_conn = r->request_time;
+    entry = ldap_first_entry(ldc->ldap, sga_res);
+
+    /*
+     * Get values for the provided sub-group attributes.
+     */
+    if (subgroupAttrs) {
+        int indx = 0, tmp_sgcIndex;
+
+        while (subgroupAttrs[indx]) {
+            char **values;
+            int val_index = 0;
+
+            /* Get *all* matching "member" values from this group. */
+            values = ldap_get_values(ldc->ldap, entry, subgroupAttrs[indx]);
+
+            if (values) {
+                val_index = 0;
+                /*
+                 * Now we are going to pare the subgroup members of this group
+                 * to *just* the subgroups, add them to the compare_nodep, and
+                 * then proceed to check the new level of subgroups.
+                 */
+                while (values[val_index]) {
+                    /* Check if this entry really is a group. */
+                    tmp_sgcIndex = 0;
+                    result = LDAP_COMPARE_FALSE;
+                    while ((tmp_sgcIndex < subgroupclasses->nelts)
+                           && (result != LDAP_COMPARE_TRUE)) {
+                        result = uldap_cache_compare(r, ldc, url,
+                                                     values[val_index],
+                                                     "objectClass",
+                                                     sgc_ents[tmp_sgcIndex].name
+                                                     );
+
+                        if (result != LDAP_COMPARE_TRUE) {
+                            tmp_sgcIndex++;
+                        }
+                    }
+                    /* It's a group, so add it to the array.  */
+                    if (result == LDAP_COMPARE_TRUE) {
+                        char **newgrp = (char **) apr_array_push(subgroups);
+                        *newgrp = apr_pstrdup(r->pool, values[val_index]);
+                    }
+                    val_index++;
+                }
+                ldap_value_free(values);
+            }
+            indx++;
+        }
+    }
+
+    ldap_msgfree(sga_res);
+
+    if (subgroups->nelts > 0) {
+        /* We need to fill in tmp_local_subgroups using the data from LDAP */
+        int sgindex;
+        char **group;
+        res = apr_pcalloc(r->pool, sizeof(util_compare_subgroup_t));
+        res->subgroupDNs  = apr_palloc(r->pool,
+                                       sizeof(char *) * (subgroups->nelts));
+        for (sgindex = 0; (group = apr_array_pop(subgroups)); sgindex++) {
+            res->subgroupDNs[sgindex] = apr_pstrdup(r->pool, *group);
+        }
+        res->len = sgindex;
+    }
+
+    return res;
+}
+
+
+/*
+ * Does a recursive lookup operation to try to find a user within (cached)
+ * nested groups. It accepts a cache that it will use to lookup previous
+ * compare attempts. We cache two kinds of compares (require group compares)
+ * and (require user compares). Each compare has a different cache node:
+ * require group includes the DN; require user does not because the require
+ * user cache is owned by the
+ *
+ * DON'T CALL THIS UNLESS YOU CALLED uldap_cache_compare FIRST!!!!!
+ *
+ *
+ * 1. Call uldap_cache_compare for each subgroupclass value to check the
+ *    generic, user-agnostic, cached group entry. This will create a new generic
+ *    cache entry if there
+ *    wasn't one. If nothing returns LDAP_COMPARE_TRUE skip to step 5 since we
+ *    have no groups.
+ * 2. Lock The cache and get the generic cache entry.
+ * 3. Check if there is already a subgrouplist in this generic group's cache
+ *    entry.
+ *    A. If there is, go to step 4.
+ *    B. If there isn't:
+ *       i)   Use ldap_search to get the full list
+ *            of subgroup "members" (which may include non-group "members").
+ *       ii)  Use uldap_cache_compare to strip the list down to just groups.
+ *       iii) Lock and add this stripped down list to the cache of the generic
+ *            group.
+ * 4. Loop through the sgl and call uldap_cache_compare (using the user info)
+ *    for each
+ *    subgroup to see if the subgroup contains the user and to get the subgroups
+ *    added to the
+ *    cache (with user-afinity, if they aren't already there).
+ *    A. If the user is in the subgroup, then we'll be returning
+ *       LDAP_COMPARE_TRUE.
+ *    B. if the user isn't in the subgroup (LDAP_COMPARE_FALSE via
+ *       uldap_cache_compare) then recursively call this function to get the
+ *       sub-subgroups added...
+ * 5. Cleanup local allocations.
+ * 6. Return the final result.
+ */
+
+static int uldap_cache_check_subgroups(request_rec *r,
+                                       util_ldap_connection_t *ldc,
+                                       const char *url, const char *dn,
+                                       const char *attrib, const char *value,
+                                       char **subgroupAttrs,
+                                       apr_array_header_t *subgroupclasses,
+                                       int cur_subgroup_depth,
+                                       int max_subgroup_depth)
+{
+    int result = LDAP_COMPARE_FALSE;
+    util_url_node_t *curl;
+    util_url_node_t curnode;
+    util_compare_node_t *compare_nodep;
+    util_compare_node_t the_compare_node;
+    util_compare_subgroup_t *tmp_local_sgl = NULL;
+    int sgl_cached_empty = 0, sgindex = 0, base_sgcIndex = 0;
+    struct mod_auth_ldap_groupattr_entry_t *sgc_ents =
+            (struct mod_auth_ldap_groupattr_entry_t *) subgroupclasses->elts;
+    util_ldap_state_t *st = (util_ldap_state_t *)
+                            ap_get_module_config(r->server->module_config,
+                                                 &ldap_module);
+
+    /*
+     * Stop looking at deeper levels of nested groups if we have reached the
+     * max. Since we already checked the top-level group in uldap_cache_compare,
+     * we don't need to check it again here - so if max_subgroup_depth is set
+     * to 0, we won't check it (i.e. that is why we check < rather than <=).
+     * We'll be calling uldap_cache_compare from here to check if the user is
+     * in the next level before we recurse into that next level looking for
+     * more subgroups.
+     */
+    if (cur_subgroup_depth >= max_subgroup_depth) {
+        return LDAP_COMPARE_FALSE;
+    }
+
+    /*
+     * 1. Check the "groupiness" of the specified basedn. Stopping at the first
+     *    TRUE return.
+     */
+    while ((base_sgcIndex < subgroupclasses->nelts)
+           && (result != LDAP_COMPARE_TRUE)) {
+        result = uldap_cache_compare(r, ldc, url, dn, "objectClass",
+                                     sgc_ents[base_sgcIndex].name);
+        if (result != LDAP_COMPARE_TRUE) {
+            base_sgcIndex++;
+        }
+    }
+
+    if (result != LDAP_COMPARE_TRUE) {
+        ldc->reason = "DN failed group verification.";
+        return result;
+    }
+
+    /*
+     * 2. Find previously created cache entry and check if there is already a
+     *    subgrouplist.
+     */
+    LDAP_CACHE_LOCK();
+    curnode.url = url;
+    curl = util_ald_cache_fetch(st->util_ldap_cache, &curnode);
+    LDAP_CACHE_UNLOCK();
+
+    if (curl && curl->compare_cache) {
+        /* make a comparison to the cache */
+        LDAP_CACHE_LOCK();
+
+        the_compare_node.dn = (char *)dn;
+        the_compare_node.attrib = (char *)"objectClass";
+        the_compare_node.value = (char *)sgc_ents[base_sgcIndex].name;
+        the_compare_node.result = 0;
+        the_compare_node.sgl_processed = 0;
+        the_compare_node.subgroupList = NULL;
+
+        compare_nodep = util_ald_cache_fetch(curl->compare_cache,
+                                             &the_compare_node);
+
+        if (compare_nodep != NULL) {
+            /*
+             * Found the generic group entry... but the user isn't in this
+             * group or we wouldn't be here.
+             */
+            if (compare_nodep->sgl_processed) {
+                if (compare_nodep->subgroupList) {
+                    /* Make a local copy of the subgroup list */
+                    int i;
+                    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01288)
+                                  "Making local copy of SGL for "
+                                  "group (%s)(objectClass=%s) ",
+                                  dn, (char *)sgc_ents[base_sgcIndex].name);
+                    tmp_local_sgl = apr_pcalloc(r->pool,
+                                                sizeof(util_compare_subgroup_t));
+                    tmp_local_sgl->len = compare_nodep->subgroupList->len;
+                    tmp_local_sgl->subgroupDNs =
+                        apr_palloc(r->pool,
+                                   sizeof(char *) * compare_nodep->subgroupList->len);
+                    for (i = 0; i < compare_nodep->subgroupList->len; i++) {
+                        tmp_local_sgl->subgroupDNs[i] =
+                            apr_pstrdup(r->pool,
+                                        compare_nodep->subgroupList->subgroupDNs[i]);
+                    }
+                }
+                else {
+                    sgl_cached_empty = 1;
+                }
+            }
+        }
+        LDAP_CACHE_UNLOCK();
+    }
+
+    if (!tmp_local_sgl && !sgl_cached_empty) {
+        /* No Cached SGL, retrieve from LDAP */
+        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01289)
+                      "no cached SGL for %s, retrieving from LDAP", dn);
+        tmp_local_sgl = uldap_get_subgroups(r, ldc, url, dn, subgroupAttrs,
+                                            subgroupclasses);
+        if (!tmp_local_sgl) {
+            /* No SGL aailable via LDAP either */
+            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01290) "no subgroups for %s",
+                          dn);
+        }
+
+      if (curl && curl->compare_cache) {
+        /*
+         * Find the generic group cache entry and add the sgl we just retrieved.
+         */
+        LDAP_CACHE_LOCK();
+
+        the_compare_node.dn = (char *)dn;
+        the_compare_node.attrib = (char *)"objectClass";
+        the_compare_node.value = (char *)sgc_ents[base_sgcIndex].name;
+        the_compare_node.result = 0;
+        the_compare_node.sgl_processed = 0;
+        the_compare_node.subgroupList = NULL;
+
+        compare_nodep = util_ald_cache_fetch(curl->compare_cache,
+                                             &the_compare_node);
+
+        if (compare_nodep == NULL) {
+            /*
+             * The group entry we want to attach our SGL to doesn't exist.
+             * We only got here if we verified this DN was actually a group
+             * based on the objectClass, but we can't call the compare function
+             * while we already hold the cache lock -- only the insert.
+             */
+            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01291)
+                          "Cache entry for %s doesn't exist", dn);
+            the_compare_node.result = LDAP_COMPARE_TRUE;
+            util_ald_cache_insert(curl->compare_cache, &the_compare_node);
+            compare_nodep = util_ald_cache_fetch(curl->compare_cache,
+                                                 &the_compare_node);
+            if (compare_nodep == NULL) {
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01292)
+                              "util_ldap: Couldn't retrieve group entry "
+                              "for %s from cache",
+                              dn);
+            }
+        }
+
+        /*
+         * We have a valid cache entry and a locally generated SGL.
+         * Attach the SGL to the cache entry
+         */
+        if (compare_nodep && !compare_nodep->sgl_processed) {
+            if (!tmp_local_sgl) {
+                /* We looked up an SGL for a group and found it to be empty */
+                if (compare_nodep->subgroupList == NULL) {
+                    compare_nodep->sgl_processed = 1;
+                }
+            }
+            else {
+                util_compare_subgroup_t *sgl_copy =
+                    util_ald_sgl_dup(curl->compare_cache, tmp_local_sgl);
+                ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, APLOGNO(01293)
+                             "Copying local SGL of len %d for group %s into cache",
+                             tmp_local_sgl->len, dn);
+                if (sgl_copy) {
+                    if (compare_nodep->subgroupList) {
+                        util_ald_sgl_free(curl->compare_cache,
+                                          &(compare_nodep->subgroupList));
+                    }
+                    compare_nodep->subgroupList = sgl_copy;
+                    compare_nodep->sgl_processed = 1;
+                }
+                else {
+                    ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server, APLOGNO(01294)
+                                 "Copy of SGL failed to obtain shared memory, "
+                                 "couldn't update cache");
+                }
+            }
+        }
+        LDAP_CACHE_UNLOCK();
+      }
+    }
+
+    /*
+     * tmp_local_sgl has either been created, or copied out of the cache
+     * If tmp_local_sgl is NULL, there are no subgroups to process and we'll
+     * return false
+     */
+    result = LDAP_COMPARE_FALSE;
+    if (!tmp_local_sgl) {
+        return result;
+    }
+
+    while ((result != LDAP_COMPARE_TRUE) && (sgindex < tmp_local_sgl->len)) {
+        const char *group = NULL;
+        group = tmp_local_sgl->subgroupDNs[sgindex];
+        /*
+         * 4. Now loop through the subgroupList and call uldap_cache_compare
+         * to check for the user.
+         */
+        result = uldap_cache_compare(r, ldc, url, group, attrib, value);
+        if (result == LDAP_COMPARE_TRUE) {
+            /*
+             * 4.A. We found the user in the subgroup. Return
+             * LDAP_COMPARE_TRUE.
+             */
+            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01295)
+                          "Found user %s in a subgroup (%s) at level %d of %d.",
+                          r->user, group, cur_subgroup_depth+1,
+                          max_subgroup_depth);
+        }
+        else {
+            /*
+             * 4.B. We didn't find the user in this subgroup, so recurse into
+             * it and keep looking.
+             */
+            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01296)
+                          "User %s not found in subgroup (%s) at level %d of "
+                          "%d.", r->user, group, cur_subgroup_depth+1,
+                          max_subgroup_depth);
+            result = uldap_cache_check_subgroups(r, ldc, url, group, attrib,
+                                                 value, subgroupAttrs,
+                                                 subgroupclasses,
+                                                 cur_subgroup_depth+1,
+                                                 max_subgroup_depth);
+        }
+        sgindex++;
+    }
+
+    return result;
+}
+
+
+static int uldap_cache_checkuserid(request_rec *r, util_ldap_connection_t *ldc,
+                                   const char *url, const char *basedn,
+                                   int scope, char **attrs, const char *filter,
+                                   const char *bindpw, const char **binddn,
+                                   const char ***retvals)
+{
+    const char **vals = NULL;
+    int numvals = 0;
+    int result = 0;
+    LDAPMessage *res, *entry;
+    char *dn;
+    int count;
+    int failures = 0;
+    util_url_node_t *curl;              /* Cached URL node */
+    util_url_node_t curnode;
+    util_search_node_t *search_nodep;   /* Cached search node */
+    util_search_node_t the_search_node;
+    apr_time_t curtime;
+
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(r->server->module_config,
+        &ldap_module);
+
+    /* Get the cache node for this url */
+    LDAP_CACHE_LOCK();
+    curnode.url = url;
+    curl = (util_url_node_t *)util_ald_cache_fetch(st->util_ldap_cache,
+                                                   &curnode);
+    if (curl == NULL) {
+        curl = util_ald_create_caches(st, url);
+    }
+    LDAP_CACHE_UNLOCK();
+
+    if (curl) {
+        LDAP_CACHE_LOCK();
+        the_search_node.username = filter;
+        search_nodep = util_ald_cache_fetch(curl->search_cache,
+                                            &the_search_node);
+        if (search_nodep != NULL) {
+
+            /* found entry in search cache... */
+            curtime = apr_time_now();
+
+            /*
+             * Remove this item from the cache if its expired. If the sent
+             * password doesn't match the storepassword, the entry will
+             * be removed and readded later if the credentials pass
+             * authentication.
+             */
+            if ((curtime - search_nodep->lastbind) > st->search_cache_ttl) {
+                /* ...but entry is too old */
+                util_ald_cache_remove(curl->search_cache, search_nodep);
+            }
+            else if (   (search_nodep->bindpw)
+                     && (search_nodep->bindpw[0] != '\0')
+                     && (strcmp(search_nodep->bindpw, bindpw) == 0))
+            {
+                /* ...and entry is valid */
+                *binddn = apr_pstrdup(r->pool, search_nodep->dn);
+                if (attrs) {
+                    int i;
+                    *retvals = apr_palloc(r->pool, sizeof(char *) * search_nodep->numvals);
+                    for (i = 0; i < search_nodep->numvals; i++) {
+                        (*retvals)[i] = apr_pstrdup(r->pool, search_nodep->vals[i]);
+                    }
+                }
+                LDAP_CACHE_UNLOCK();
+                ldc->reason = "Authentication successful (cached)";
+                return LDAP_SUCCESS;
+            }
+        }
+        /* unlock this read lock */
+        LDAP_CACHE_UNLOCK();
+    }
+
+    /*
+     * At this point, there is no valid cached search, so lets do the search.
+     */
+
+    /*
+     * If LDAP operation fails due to LDAP_SERVER_DOWN, control returns here.
+     */
+start_over:
+    if (failures > st->retries) {
+        return result;
+    }
+
+    if (failures > 0 && st->retry_delay > 0) {
+        apr_sleep(st->retry_delay);
+    }
+
+    if (LDAP_SUCCESS != (result = uldap_connection_open(r, ldc))) {
+        return result;
+    }
+
+    /* try do the search */
+    result = ldap_search_ext_s(ldc->ldap,
+                               (char *)basedn, scope,
+                               (char *)filter, attrs, 0,
+                               NULL, NULL, st->opTimeout, APR_LDAP_SIZELIMIT, &res);
+    if (AP_LDAP_IS_SERVER_DOWN(result))
+    {
+        ldc->reason = "ldap_search_ext_s() for user failed with server down";
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+
+    if (result == LDAP_TIMEOUT) {
+        ldc->reason = "ldap_search_ext_s() for user failed with timeout";
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+
+
+    /* if there is an error (including LDAP_NO_SUCH_OBJECT) return now */
+    if (result != LDAP_SUCCESS) {
+        ldc->reason = "ldap_search_ext_s() for user failed";
+        return result;
+    }
+
+    /*
+     * We should have found exactly one entry; to find a different
+     * number is an error.
+     */
+    ldc->last_backend_conn = r->request_time;
+    count = ldap_count_entries(ldc->ldap, res);
+    if (count != 1)
+    {
+        if (count == 0 )
+            ldc->reason = "User not found";
+        else
+            ldc->reason = "User is not unique (search found two "
+                          "or more matches)";
+        ldap_msgfree(res);
+        return LDAP_NO_SUCH_OBJECT;
+    }
+
+    entry = ldap_first_entry(ldc->ldap, res);
+
+    /* Grab the dn, copy it into the pool, and free it again */
+    dn = ldap_get_dn(ldc->ldap, entry);
+    *binddn = apr_pstrdup(r->pool, dn);
+    ldap_memfree(dn);
+
+    /*
+     * A bind to the server with an empty password always succeeds, so
+     * we check to ensure that the password is not empty. This implies
+     * that users who actually do have empty passwords will never be
+     * able to authenticate with this module. I don't see this as a big
+     * problem.
+     */
+    if (!bindpw || strlen(bindpw) <= 0) {
+        ldap_msgfree(res);
+        ldc->reason = "Empty password not allowed";
+        return LDAP_INVALID_CREDENTIALS;
+    }
+
+    /*
+     * Attempt to bind with the retrieved dn and the password. If the bind
+     * fails, it means that the password is wrong (the dn obviously
+     * exists, since we just retrieved it)
+     */
+    result = uldap_simple_bind(ldc, (char *)*binddn, (char *)bindpw,
+                               st->opTimeout);
+    if (AP_LDAP_IS_SERVER_DOWN(result) ||
+        (result == LDAP_TIMEOUT && failures == 0)) {
+        if (AP_LDAP_IS_SERVER_DOWN(result))
+            ldc->reason = "ldap_simple_bind() to check user credentials "
+                          "failed with server down";
+        else
+            ldc->reason = "ldap_simple_bind() to check user credentials "
+                          "timed out";
+        ldap_msgfree(res);
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+
+    /* failure? if so - return */
+    if (result != LDAP_SUCCESS) {
+        ldc->reason = "ldap_simple_bind() to check user credentials failed";
+        ldap_msgfree(res);
+        uldap_connection_unbind(ldc);
+        return result;
+    }
+    else {
+        /*
+         * We have just bound the connection to a different user and password
+         * combination, which might be reused unintentionally next time this
+         * connection is used from the connection pool.
+         */
+        ldc->must_rebind = 1;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "LDC %pp used for authn, must be rebound", ldc);
+    }
+
+    /*
+     * Get values for the provided attributes.
+     */
+    if (attrs) {
+        int k = 0;
+        int i = 0;
+        while (attrs[k++]);
+        vals = apr_pcalloc(r->pool, sizeof(char *) * (k+1));
+        numvals = k;
+        while (attrs[i]) {
+            char **values;
+            int j = 0;
+            char *str = NULL;
+            /* get values */
+            values = ldap_get_values(ldc->ldap, entry, attrs[i]);
+            while (values && values[j]) {
+                str = str ? apr_pstrcat(r->pool, str, "; ", values[j], NULL)
+                          : apr_pstrdup(r->pool, values[j]);
+                j++;
+            }
+            ldap_value_free(values);
+            vals[i] = str;
+            i++;
+        }
+        *retvals = vals;
+    }
+
+    /*
+     * Add the new username to the search cache.
+     */
+    if (curl) {
+        LDAP_CACHE_LOCK();
+        the_search_node.username = filter;
+        the_search_node.dn = *binddn;
+        the_search_node.bindpw = bindpw;
+        the_search_node.lastbind = apr_time_now();
+        the_search_node.vals = vals;
+        the_search_node.numvals = numvals;
+
+        /* Search again to make sure that another thread didn't ready insert
+         * this node into the cache before we got here. If it does exist then
+         * update the lastbind
+         */
+        search_nodep = util_ald_cache_fetch(curl->search_cache,
+                                            &the_search_node);
+        if ((search_nodep == NULL) ||
+            (strcmp(*binddn, search_nodep->dn) != 0)) {
+
+            /* Nothing in cache, insert new entry */
+            util_ald_cache_insert(curl->search_cache, &the_search_node);
+        }
+        else if ((!search_nodep->bindpw) ||
+            (strcmp(bindpw, search_nodep->bindpw) != 0)) {
+
+            /* Entry in cache is invalid, remove it and insert new one */
+            util_ald_cache_remove(curl->search_cache, search_nodep);
+            util_ald_cache_insert(curl->search_cache, &the_search_node);
+        }
+        else {
+            /* Cache entry is valid, update lastbind */
+            search_nodep->lastbind = the_search_node.lastbind;
+        }
+        LDAP_CACHE_UNLOCK();
+    }
+    ldap_msgfree(res);
+
+    ldc->reason = "Authentication successful";
+    return LDAP_SUCCESS;
+}
+
+/*
+ * This function will return the DN of the entry matching userid.
+ * It is used to get the DN in case some other module than mod_auth_ldap
+ * has authenticated the user.
+ * The function is basically a copy of uldap_cache_checkuserid
+ * with password checking removed.
+ */
+static int uldap_cache_getuserdn(request_rec *r, util_ldap_connection_t *ldc,
+                                 const char *url, const char *basedn,
+                                 int scope, char **attrs, const char *filter,
+                                 const char **binddn, const char ***retvals)
+{
+    const char **vals = NULL;
+    int numvals = 0;
+    int result = 0;
+    LDAPMessage *res, *entry;
+    char *dn;
+    int count;
+    int failures = 0;
+    util_url_node_t *curl;              /* Cached URL node */
+    util_url_node_t curnode;
+    util_search_node_t *search_nodep;   /* Cached search node */
+    util_search_node_t the_search_node;
+    apr_time_t curtime;
+
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(r->server->module_config,
+        &ldap_module);
+
+    /* Get the cache node for this url */
+    LDAP_CACHE_LOCK();
+    curnode.url = url;
+    curl = (util_url_node_t *)util_ald_cache_fetch(st->util_ldap_cache,
+                                                   &curnode);
+    if (curl == NULL) {
+        curl = util_ald_create_caches(st, url);
+    }
+    LDAP_CACHE_UNLOCK();
+
+    if (curl) {
+        LDAP_CACHE_LOCK();
+        the_search_node.username = filter;
+        search_nodep = util_ald_cache_fetch(curl->search_cache,
+                                            &the_search_node);
+        if (search_nodep != NULL) {
+
+            /* found entry in search cache... */
+            curtime = apr_time_now();
+
+            /*
+             * Remove this item from the cache if its expired.
+             */
+            if ((curtime - search_nodep->lastbind) > st->search_cache_ttl) {
+                /* ...but entry is too old */
+                util_ald_cache_remove(curl->search_cache, search_nodep);
+            }
+            else {
+                /* ...and entry is valid */
+                *binddn = apr_pstrdup(r->pool, search_nodep->dn);
+                if (attrs) {
+                    int i;
+                    *retvals = apr_palloc(r->pool, sizeof(char *) * search_nodep->numvals);
+                    for (i = 0; i < search_nodep->numvals; i++) {
+                        (*retvals)[i] = apr_pstrdup(r->pool, search_nodep->vals[i]);
+                    }
+                }
+                LDAP_CACHE_UNLOCK();
+                ldc->reason = "Search successful (cached)";
+                return LDAP_SUCCESS;
+            }
+        }
+        /* unlock this read lock */
+        LDAP_CACHE_UNLOCK();
+    }
+
+    /*
+     * At this point, there is no valid cached search, so lets do the search.
+     */
+
+    /*
+     * If LDAP operation fails due to LDAP_SERVER_DOWN, control returns here.
+     */
+start_over:
+    if (failures > st->retries) {
+        return result;
+    }
+
+    if (failures > 0 && st->retry_delay > 0) {
+        apr_sleep(st->retry_delay);
+    }
+
+    if (LDAP_SUCCESS != (result = uldap_connection_open(r, ldc))) {
+        return result;
+    }
+
+    /* try do the search */
+    result = ldap_search_ext_s(ldc->ldap,
+                               (char *)basedn, scope,
+                               (char *)filter, attrs, 0,
+                               NULL, NULL, st->opTimeout, APR_LDAP_SIZELIMIT, &res);
+    if (AP_LDAP_IS_SERVER_DOWN(result))
+    {
+        ldc->reason = "ldap_search_ext_s() for user failed with server down";
+        uldap_connection_unbind(ldc);
+        failures++;
+        ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r, "%s (attempt %d)", ldc->reason, failures);
+        goto start_over;
+    }
+
+    /* if there is an error (including LDAP_NO_SUCH_OBJECT) return now */
+    if (result != LDAP_SUCCESS) {
+        ldc->reason = "ldap_search_ext_s() for user failed";
+        return result;
+    }
+
+    /*
+     * We should have found exactly one entry; to find a different
+     * number is an error.
+     */
+    ldc->last_backend_conn = r->request_time;
+    count = ldap_count_entries(ldc->ldap, res);
+    if (count != 1)
+    {
+        if (count == 0 )
+            ldc->reason = "User not found";
+        else
+            ldc->reason = "User is not unique (search found two "
+                          "or more matches)";
+        ldap_msgfree(res);
+        return LDAP_NO_SUCH_OBJECT;
+    }
+
+    entry = ldap_first_entry(ldc->ldap, res);
+
+    /* Grab the dn, copy it into the pool, and free it again */
+    dn = ldap_get_dn(ldc->ldap, entry);
+    *binddn = apr_pstrdup(r->pool, dn);
+    ldap_memfree(dn);
+
+    /*
+     * Get values for the provided attributes.
+     */
+    if (attrs) {
+        int k = 0;
+        int i = 0;
+        while (attrs[k++]);
+        vals = apr_pcalloc(r->pool, sizeof(char *) * (k+1));
+        numvals = k;
+        while (attrs[i]) {
+            char **values;
+            int j = 0;
+            char *str = NULL;
+            /* get values */
+            values = ldap_get_values(ldc->ldap, entry, attrs[i]);
+            while (values && values[j]) {
+                str = str ? apr_pstrcat(r->pool, str, "; ", values[j], NULL)
+                          : apr_pstrdup(r->pool, values[j]);
+                j++;
+            }
+            ldap_value_free(values);
+            vals[i] = str;
+            i++;
+        }
+        *retvals = vals;
+    }
+
+    /*
+     * Add the new username to the search cache.
+     */
+    if (curl) {
+        LDAP_CACHE_LOCK();
+        the_search_node.username = filter;
+        the_search_node.dn = *binddn;
+        the_search_node.bindpw = NULL;
+        the_search_node.lastbind = apr_time_now();
+        the_search_node.vals = vals;
+        the_search_node.numvals = numvals;
+
+        /* Search again to make sure that another thread didn't ready insert
+         * this node into the cache before we got here. If it does exist then
+         * update the lastbind
+         */
+        search_nodep = util_ald_cache_fetch(curl->search_cache,
+                                            &the_search_node);
+        if ((search_nodep == NULL) ||
+            (strcmp(*binddn, search_nodep->dn) != 0)) {
+
+            /* Nothing in cache, insert new entry */
+            util_ald_cache_insert(curl->search_cache, &the_search_node);
+        }
+        /*
+         * Don't update lastbind on entries with bindpw because
+         * we haven't verified that password. It's OK to update
+         * the entry if there is no password in it.
+         */
+        else if (!search_nodep->bindpw) {
+            /* Cache entry is valid, update lastbind */
+            search_nodep->lastbind = the_search_node.lastbind;
+        }
+        LDAP_CACHE_UNLOCK();
+    }
+
+    ldap_msgfree(res);
+
+    ldc->reason = "Search successful";
+    return LDAP_SUCCESS;
+}
+
+/*
+ * Reports if ssl support is enabled
+ *
+ * 1 = enabled, 0 = not enabled
+ */
+static int uldap_ssl_supported(request_rec *r)
+{
+   util_ldap_state_t *st = (util_ldap_state_t *)ap_get_module_config(
+                                r->server->module_config, &ldap_module);
+
+   return(st->ssl_supported);
+}
+
+
+/* ---------------------------------------- */
+/* config directives */
+
+
+static const char *util_ldap_set_cache_bytes(cmd_parms *cmd, void *dummy,
+                                             const char *bytes)
+{
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    st->cache_bytes = atol(bytes);
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01297)
+                 "ldap cache: Setting shared memory cache size to "
+                 "%" APR_SIZE_T_FMT " bytes.",
+                 st->cache_bytes);
+
+    return NULL;
+}
+
+static const char *util_ldap_set_cache_file(cmd_parms *cmd, void *dummy,
+                                            const char *file)
+{
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    if (file) {
+        st->cache_file = ap_server_root_relative(st->pool, file);
+    }
+    else {
+        st->cache_file = NULL;
+    }
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01298)
+                 "LDAP cache: Setting shared memory cache file to %s.",
+                 st->cache_file);
+
+    return NULL;
+}
+
+static const char *util_ldap_set_cache_ttl(cmd_parms *cmd, void *dummy,
+                                           const char *ttl)
+{
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    st->search_cache_ttl = atol(ttl) * 1000000;
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01299)
+                 "ldap cache: Setting cache TTL to %ld microseconds.",
+                 st->search_cache_ttl);
+
+    return NULL;
+}
+
+static const char *util_ldap_set_cache_entries(cmd_parms *cmd, void *dummy,
+                                               const char *size)
+{
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    st->search_cache_size = atol(size);
+    if (st->search_cache_size < 0) {
+        st->search_cache_size = 0;
+    }
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01300)
+                 "ldap cache: Setting search cache size to %ld entries.",
+                 st->search_cache_size);
+
+    return NULL;
+}
+
+static const char *util_ldap_set_opcache_ttl(cmd_parms *cmd, void *dummy,
+                                             const char *ttl)
+{
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    st->compare_cache_ttl = atol(ttl) * APR_USEC_PER_SEC;
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01301)
+                 "ldap cache: Setting operation cache TTL to %ld microseconds.",
+                 st->compare_cache_ttl);
+
+    return NULL;
+}
+
+static const char *util_ldap_set_opcache_entries(cmd_parms *cmd, void *dummy,
+                                                 const char *size)
+{
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    st->compare_cache_size = atol(size);
+    if (st->compare_cache_size < 0) {
+        st->compare_cache_size = 0;
+    }
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01302)
+                 "ldap cache: Setting operation cache size to %ld entries.",
+                 st->compare_cache_size);
+
+    return NULL;
+}
+
+
+/**
+ * Parse the certificate type.
+ *
+ * The type can be one of the following:
+ * CA_DER, CA_BASE64, CA_CERT7_DB, CA_SECMOD, CERT_DER, CERT_BASE64,
+ * CERT_KEY3_DB, CERT_NICKNAME, KEY_DER, KEY_BASE64
+ *
+ * If no matches are found, APR_LDAP_CA_TYPE_UNKNOWN is returned.
+ */
+static int util_ldap_parse_cert_type(const char *type)
+{
+    /* Authority file in binary DER format */
+    if (0 == strcasecmp("CA_DER", type)) {
+        return APR_LDAP_CA_TYPE_DER;
+    }
+
+    /* Authority file in Base64 format */
+    else if (0 == strcasecmp("CA_BASE64", type)) {
+        return APR_LDAP_CA_TYPE_BASE64;
+    }
+
+    /* Netscape certificate database file/directory */
+    else if (0 == strcasecmp("CA_CERT7_DB", type)) {
+        return APR_LDAP_CA_TYPE_CERT7_DB;
+    }
+
+    /* Netscape secmod file/directory */
+    else if (0 == strcasecmp("CA_SECMOD", type)) {
+        return APR_LDAP_CA_TYPE_SECMOD;
+    }
+
+    /* Client cert file in DER format */
+    else if (0 == strcasecmp("CERT_DER", type)) {
+        return APR_LDAP_CERT_TYPE_DER;
+    }
+
+    /* Client cert file in Base64 format */
+    else if (0 == strcasecmp("CERT_BASE64", type)) {
+        return APR_LDAP_CERT_TYPE_BASE64;
+    }
+
+    /* Client cert file in PKCS#12 format */
+    else if (0 == strcasecmp("CERT_PFX", type)) {
+        return APR_LDAP_CERT_TYPE_PFX;
+    }
+
+    /* Netscape client cert database file/directory */
+    else if (0 == strcasecmp("CERT_KEY3_DB", type)) {
+        return APR_LDAP_CERT_TYPE_KEY3_DB;
+    }
+
+    /* Netscape client cert nickname */
+    else if (0 == strcasecmp("CERT_NICKNAME", type)) {
+        return APR_LDAP_CERT_TYPE_NICKNAME;
+    }
+
+    /* Client cert key file in DER format */
+    else if (0 == strcasecmp("KEY_DER", type)) {
+        return APR_LDAP_KEY_TYPE_DER;
+    }
+
+    /* Client cert key file in Base64 format */
+    else if (0 == strcasecmp("KEY_BASE64", type)) {
+        return APR_LDAP_KEY_TYPE_BASE64;
+    }
+
+    /* Client cert key file in PKCS#12 format */
+    else if (0 == strcasecmp("KEY_PFX", type)) {
+        return APR_LDAP_KEY_TYPE_PFX;
+    }
+
+    else {
+        return APR_LDAP_CA_TYPE_UNKNOWN;
+    }
+
+}
+
+
+/**
+ * Set LDAPTrustedGlobalCert.
+ *
+ * This directive takes either two or three arguments:
+ * - certificate type
+ * - certificate file / directory / nickname
+ * - certificate password (optional)
+ *
+ * This directive may only be used globally.
+ */
+static const char *util_ldap_set_trusted_global_cert(cmd_parms *cmd,
+                                                     void *dummy,
+                                                     const char *type,
+                                                     const char *file,
+                                                     const char *password)
+{
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+    apr_finfo_t finfo;
+    apr_status_t rv;
+    int cert_type = 0;
+    apr_ldap_opt_tls_cert_t *cert;
+
+    if (err != NULL) {
+        return err;
+    }
+
+    /* handle the certificate type */
+    if (type) {
+        cert_type = util_ldap_parse_cert_type(type);
+        if (APR_LDAP_CA_TYPE_UNKNOWN == cert_type) {
+           return apr_psprintf(cmd->pool, "The certificate type %s is "
+                                          "not recognised. It should be one "
+                                          "of CA_DER, CA_BASE64, CA_CERT7_DB, "
+                                          "CA_SECMOD, CERT_DER, CERT_BASE64, "
+                                          "CERT_KEY3_DB, CERT_NICKNAME, "
+                                          "KEY_DER, KEY_BASE64", type);
+        }
+    }
+    else {
+        return "Certificate type was not specified.";
+    }
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01303)
+                      "LDAP: SSL trusted global cert - %s (type %s)",
+                       file, type);
+
+    /* add the certificate to the global array */
+    cert = (apr_ldap_opt_tls_cert_t *)apr_array_push(st->global_certs);
+    cert->type = cert_type;
+    cert->path = file;
+    cert->password = password;
+
+    /* if file is a file or path, fix the path */
+    if (cert_type != APR_LDAP_CA_TYPE_UNKNOWN &&
+        cert_type != APR_LDAP_CERT_TYPE_NICKNAME) {
+
+        cert->path = ap_server_root_relative(cmd->pool, file);
+        if (cert->path &&
+            ((rv = apr_stat (&finfo, cert->path, APR_FINFO_MIN, cmd->pool))
+                != APR_SUCCESS))
+        {
+            ap_log_error(APLOG_MARK, APLOG_ERR, rv, cmd->server, APLOGNO(01304)
+                         "LDAP: Could not open SSL trusted certificate "
+                         "authority file - %s",
+                         cert->path == NULL ? file : cert->path);
+            return "Invalid global certificate file path";
+        }
+    }
+
+    return(NULL);
+}
+
+
+/**
+ * Set LDAPTrustedClientCert.
+ *
+ * This directive takes either two or three arguments:
+ * - certificate type
+ * - certificate file / directory / nickname
+ * - certificate password (optional)
+ */
+static const char *util_ldap_set_trusted_client_cert(cmd_parms *cmd,
+                                                     void *config,
+                                                     const char *type,
+                                                     const char *file,
+                                                     const char *password)
+{
+    util_ldap_config_t *dc =  config;
+    apr_finfo_t finfo;
+    apr_status_t rv;
+    int cert_type = 0;
+    apr_ldap_opt_tls_cert_t *cert;
+
+    /* handle the certificate type */
+    if (type) {
+        cert_type = util_ldap_parse_cert_type(type);
+        if (APR_LDAP_CA_TYPE_UNKNOWN == cert_type) {
+            return apr_psprintf(cmd->pool, "The certificate type \"%s\" is "
+                                           "not recognised. It should be one "
+                                           "of CA_DER, CA_BASE64, "
+                                           "CERT_DER, CERT_BASE64, "
+                                           "CERT_NICKNAME, CERT_PFX, "
+                                           "KEY_DER, KEY_BASE64, KEY_PFX",
+                                           type);
+        }
+        else if ( APR_LDAP_CA_TYPE_CERT7_DB == cert_type ||
+                 APR_LDAP_CA_TYPE_SECMOD == cert_type ||
+                 APR_LDAP_CERT_TYPE_PFX == cert_type ||
+                 APR_LDAP_CERT_TYPE_KEY3_DB == cert_type) {
+            return apr_psprintf(cmd->pool, "The certificate type \"%s\" is "
+                                           "only valid within a "
+                                           "LDAPTrustedGlobalCert directive. "
+                                           "Only CA_DER, CA_BASE64, "
+                                           "CERT_DER, CERT_BASE64, "
+                                           "CERT_NICKNAME, KEY_DER, and "
+                                           "KEY_BASE64 may be used.", type);
+        }
+    }
+    else {
+        return "Certificate type was not specified.";
+    }
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01305)
+                      "LDAP: SSL trusted client cert - %s (type %s)",
+                       file, type);
+
+    /* add the certificate to the client array */
+    cert = (apr_ldap_opt_tls_cert_t *)apr_array_push(dc->client_certs);
+    cert->type = cert_type;
+    cert->path = file;
+    cert->password = password;
+
+    /* if file is a file or path, fix the path */
+    if (cert_type != APR_LDAP_CA_TYPE_UNKNOWN &&
+        cert_type != APR_LDAP_CERT_TYPE_NICKNAME) {
+
+        cert->path = ap_server_root_relative(cmd->pool, file);
+        if (cert->path &&
+            ((rv = apr_stat (&finfo, cert->path, APR_FINFO_MIN, cmd->pool))
+                != APR_SUCCESS))
+        {
+            ap_log_error(APLOG_MARK, APLOG_ERR, rv, cmd->server, APLOGNO(01306)
+                         "LDAP: Could not open SSL client certificate "
+                         "file - %s",
+                         cert->path == NULL ? file : cert->path);
+            return "Invalid client certificate file path";
+        }
+
+    }
+
+    return(NULL);
+}
+
+
+/**
+ * Set LDAPTrustedMode.
+ *
+ * This directive sets what encryption mode to use on a connection:
+ * - None (No encryption)
+ * - SSL (SSL encryption)
+ * - STARTTLS (TLS encryption)
+ */
+static const char *util_ldap_set_trusted_mode(cmd_parms *cmd, void *dummy,
+                                              const char *mode)
+{
+    util_ldap_state_t *st =
+    (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                              &ldap_module);
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01307)
+                      "LDAP: SSL trusted mode - %s",
+                       mode);
+
+    if (0 == strcasecmp("NONE", mode)) {
+        st->secure = APR_LDAP_NONE;
+    }
+    else if (0 == strcasecmp("SSL", mode)) {
+        st->secure = APR_LDAP_SSL;
+    }
+    else if (   (0 == strcasecmp("TLS", mode))
+             || (0 == strcasecmp("STARTTLS", mode))) {
+        st->secure = APR_LDAP_STARTTLS;
+    }
+    else {
+        return "Invalid LDAPTrustedMode setting: must be one of NONE, "
+               "SSL, or TLS/STARTTLS";
+    }
+
+    st->secure_set = 1;
+    return(NULL);
+}
+
+static const char *util_ldap_set_verify_srv_cert(cmd_parms *cmd,
+                                                 void *dummy,
+                                                 int mode)
+{
+    util_ldap_state_t *st =
+    (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                              &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01308)
+                      "LDAP: SSL verify server certificate - %s",
+                      mode?"TRUE":"FALSE");
+
+    st->verify_svr_cert = mode;
+
+    return(NULL);
+}
+
+
+static const char *util_ldap_set_connection_timeout(cmd_parms *cmd,
+                                                    void *dummy,
+                                                    const char *ttl)
+{
+#ifdef LDAP_OPT_NETWORK_TIMEOUT
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+#endif
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+#ifdef LDAP_OPT_NETWORK_TIMEOUT
+    st->connectionTimeout = atol(ttl);
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01309)
+                 "ldap connection: Setting connection timeout to %ld seconds.",
+                 st->connectionTimeout);
+#else
+    ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, cmd->server, APLOGNO(01310)
+                 "LDAP: Connection timeout option not supported by the "
+                 "LDAP SDK in use." );
+#endif
+
+    return NULL;
+}
+
+
+static const char *util_ldap_set_chase_referrals(cmd_parms *cmd,
+                                                 void *config,
+                                                 const char *arg)
+{
+    util_ldap_config_t *dc =  config;
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01311)
+                      "LDAP: Setting referral chasing %s", arg);
+
+    if (0 == strcasecmp(arg, "on")) {
+        dc->ChaseReferrals = AP_LDAP_CHASEREFERRALS_ON;
+    }
+    else if (0 == strcasecmp(arg, "off")) {
+        dc->ChaseReferrals = AP_LDAP_CHASEREFERRALS_OFF;
+    }
+    else if (0 == strcasecmp(arg, "default")) {
+        dc->ChaseReferrals = AP_LDAP_CHASEREFERRALS_SDKDEFAULT;
+    }
+    else {
+        return "LDAPReferrals must be 'on', 'off', or 'default'";
+    }
+
+    return(NULL);
+}
+
+static const char *util_ldap_set_debug_level(cmd_parms *cmd,
+                                             void *config,
+                                             const char *arg) {
+#ifdef AP_LDAP_OPT_DEBUG
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+#endif
+
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+    if (err != NULL) {
+        return err;
+    }
+
+#ifndef AP_LDAP_OPT_DEBUG
+    return "This directive is not supported with the currently linked LDAP library";
+#else
+    st->debug_level = atoi(arg);
+    return NULL;
+#endif
+}
+
+static const char *util_ldap_set_referral_hop_limit(cmd_parms *cmd,
+                                                    void *config,
+                                                    const char *hop_limit)
+{
+    util_ldap_config_t *dc =  config;
+
+    dc->ReferralHopLimit = atol(hop_limit);
+
+    if (dc->ReferralHopLimit <= 0) {
+        return "LDAPReferralHopLimit must be greater than zero (Use 'LDAPReferrals Off' to disable referral chasing)";
+    }
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01312)
+                 "LDAP: Limit chased referrals to maximum of %d hops.",
+                 dc->ReferralHopLimit);
+
+    return NULL;
+}
+
+static void *util_ldap_create_dir_config(apr_pool_t *p, char *d)
+{
+    util_ldap_config_t *dc =
+        (util_ldap_config_t *) apr_pcalloc(p,sizeof(util_ldap_config_t));
+
+    /* defaults are AP_LDAP_CHASEREFERRALS_ON and AP_LDAP_DEFAULT_HOPLIMIT */
+    dc->client_certs = apr_array_make(p, 10, sizeof(apr_ldap_opt_tls_cert_t));
+    dc->ChaseReferrals = AP_LDAP_CHASEREFERRALS_ON;
+    dc->ReferralHopLimit = AP_LDAP_HOPLIMIT_UNSET;
+
+    return dc;
+}
+
+static const char *util_ldap_set_op_timeout(cmd_parms *cmd,
+                                            void *dummy,
+                                            const char *val)
+{
+    long timeout;
+    char *endptr;
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    timeout = strtol(val, &endptr, 10);
+    if ((val == endptr) || (*endptr != '\0')) {
+        return "Timeout not numerical";
+    }
+    if (timeout < 0) {
+        return "Timeout must be non-negative";
+    }
+
+    if (timeout) {
+        if (!st->opTimeout) {
+            st->opTimeout = apr_pcalloc(cmd->pool, sizeof(struct timeval));
+        }
+        st->opTimeout->tv_sec = timeout;
+    }
+    else {
+        st->opTimeout = NULL;
+    }
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01313)
+                 "ldap connection: Setting op timeout to %ld seconds.",
+                 timeout);
+
+#ifndef LDAP_OPT_TIMEOUT
+
+    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01314)
+                 "LDAP: LDAP_OPT_TIMEOUT option not supported by the "
+                 "LDAP library in use. Using LDAPTimeout value as search "
+                 "timeout only." );
+#endif
+
+    return NULL;
+}
+
+static const char *util_ldap_set_conn_ttl(cmd_parms *cmd,
+                                          void *dummy,
+                                          const char *val)
+{
+    apr_interval_time_t timeout;
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+
+    if (ap_timeout_parameter_parse(val, &timeout, "s") != APR_SUCCESS) {
+        return "LDAPConnectionPoolTTL has wrong format";
+    }
+
+    if (timeout < 0) {
+        /* reserve -1 for default value */
+        timeout = AP_LDAP_CONNPOOL_INFINITE;
+    }
+    st->connection_pool_ttl = timeout;
+    return NULL;
+}
+
+static const char *util_ldap_set_retry_delay(cmd_parms *cmd,
+                                             void *dummy,
+                                             const char *val)
+{
+    apr_interval_time_t timeout;
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    if (ap_timeout_parameter_parse(val, &timeout, "s") != APR_SUCCESS) {
+        return "LDAPRetryDelay has wrong format";
+    }
+
+    if (timeout < 0) {
+        return "LDAPRetryDelay must be >= 0";
+    }
+
+    st->retry_delay = timeout;
+    return NULL;
+}
+
+static const char *util_ldap_set_retries(cmd_parms *cmd,
+                                         void *dummy,
+                                         const char *val)
+{
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)ap_get_module_config(cmd->server->module_config,
+                                                  &ldap_module);
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    st->retries = atoi(val);
+    if (st->retries < 0) {
+        return  "LDAPRetries must be >= 0";
+    }
+
+    return NULL;
+}
+
+static void *util_ldap_create_config(apr_pool_t *p, server_rec *s)
+{
+    util_ldap_state_t *st =
+        (util_ldap_state_t *)apr_pcalloc(p, sizeof(util_ldap_state_t));
+
+    /* Create a per vhost pool for mod_ldap to use, serialized with
+     * st->mutex (also one per vhost).  both are replicated by fork(),
+     * no shared memory managed by either.
+     */
+    apr_pool_create(&st->pool, p);
+#if APR_HAS_THREADS
+    apr_thread_mutex_create(&st->mutex, APR_THREAD_MUTEX_DEFAULT, st->pool);
+#endif
+
+    st->cache_bytes = 500000;
+    st->search_cache_ttl = 600 * APR_USEC_PER_SEC; /* 10 minutes */
+    st->search_cache_size = 1024;
+    st->compare_cache_ttl = 600 * APR_USEC_PER_SEC; /* 10 minutes */
+    st->compare_cache_size = 1024;
+    st->connections = NULL;
+    st->ssl_supported = 0;
+    st->global_certs = apr_array_make(p, 10, sizeof(apr_ldap_opt_tls_cert_t));
+    st->secure = APR_LDAP_NONE;
+    st->secure_set = 0;
+    st->connectionTimeout = 10;
+    st->opTimeout = apr_pcalloc(p, sizeof(struct timeval));
+    st->opTimeout->tv_sec = 60;
+    st->verify_svr_cert = 1;
+    st->connection_pool_ttl = AP_LDAP_CONNPOOL_DEFAULT; /* no limit */
+    st->retries = 3;
+    st->retry_delay = 0; /* no delay */
+
+    return st;
+}
+
+/* cache-related settings are not merged here, but in the post_config hook,
+ * since the cache has not yet sprung to life
+ */
+static void *util_ldap_merge_config(apr_pool_t *p, void *basev,
+                                    void *overridesv)
+{
+    util_ldap_state_t *st = apr_pcalloc(p, sizeof(util_ldap_state_t));
+    util_ldap_state_t *base = (util_ldap_state_t *) basev;
+    util_ldap_state_t *overrides = (util_ldap_state_t *) overridesv;
+
+    st->pool = overrides->pool;
+#if APR_HAS_THREADS
+    st->mutex = overrides->mutex;
+#endif
+
+    /* The cache settings can not be modified in a
+        virtual host since all server use the same
+        shared memory cache. */
+    st->cache_bytes = base->cache_bytes;
+    st->search_cache_ttl = base->search_cache_ttl;
+    st->search_cache_size = base->search_cache_size;
+    st->compare_cache_ttl = base->compare_cache_ttl;
+    st->compare_cache_size = base->compare_cache_size;
+
+    st->connections = NULL;
+    st->ssl_supported = 0; /* not known until post-config and re-merged */
+    st->global_certs = apr_array_append(p, base->global_certs,
+                                           overrides->global_certs);
+    st->secure = (overrides->secure_set == 0) ? base->secure
+                                              : overrides->secure;
+
+    /* These LDAP connection settings can not be overwritten in
+        a virtual host. Once set in the base server, they must
+        remain the same. None of the LDAP SDKs seem to be able
+        to handle setting the verify_svr_cert flag on a
+        per-connection basis.  The OpenLDAP client appears to be
+        able to handle the connection timeout per-connection
+        but the Novell SDK cannot.  Allowing the timeout to
+        be set by each vhost is of little value so rather than
+        trying to make special expections for one LDAP SDK, GLOBAL_ONLY
+        is being enforced on this setting as well. */
+    st->connectionTimeout = base->connectionTimeout;
+    st->opTimeout = base->opTimeout;
+    st->verify_svr_cert = base->verify_svr_cert;
+    st->debug_level = base->debug_level;
+
+    st->connection_pool_ttl = (overrides->connection_pool_ttl == AP_LDAP_CONNPOOL_DEFAULT) ?
+                                base->connection_pool_ttl : overrides->connection_pool_ttl;
+
+    st->retries = base->retries;
+    st->retry_delay = base->retry_delay;
+
+    return st;
+}
+
+static apr_status_t util_ldap_cleanup_module(void *data)
+{
+    server_rec *s = data;
+    util_ldap_state_t *st = (util_ldap_state_t *)ap_get_module_config(
+        s->module_config, &ldap_module);
+
+    if (st->ssl_supported) {
+        apr_ldap_ssl_deinit();
+    }
+
+    return APR_SUCCESS;
+}
+
+static int util_ldap_pre_config(apr_pool_t *pconf, apr_pool_t *plog,
+                                apr_pool_t *ptemp)
+{
+    apr_status_t result;
+
+    result = ap_mutex_register(pconf, ldap_cache_mutex_type, NULL,
+                               APR_LOCK_DEFAULT, 0);
+    if (result != APR_SUCCESS) {
+        return result;
+    }
+
+    return OK;
+}
+
+static int util_ldap_post_config(apr_pool_t *p, apr_pool_t *plog,
+                                 apr_pool_t *ptemp, server_rec *s)
+{
+    apr_status_t result;
+    server_rec *s_vhost;
+    util_ldap_state_t *st_vhost;
+
+    util_ldap_state_t *st = (util_ldap_state_t *)
+                            ap_get_module_config(s->module_config,
+                                                 &ldap_module);
+
+    apr_ldap_err_t *result_err = NULL;
+    int rc;
+
+    /* util_ldap_post_config() will be called twice. Don't bother
+     * going through all of the initialization on the first call
+     * because it will just be thrown away.*/
+    if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_PRE_CONFIG) {
+
+#if APR_HAS_SHARED_MEMORY
+        /*
+         * If we are using shared memory caching and the cache file already
+         * exists then delete it.  Otherwise we are going to run into problems
+         * creating the shared memory.
+         */
+        if (st->cache_file && st->cache_bytes > 0) {
+            char *lck_file = apr_pstrcat(ptemp, st->cache_file, ".lck",
+                                         NULL);
+            apr_file_remove(lck_file, ptemp);
+        }
+#endif
+        return OK;
+    }
+
+#if APR_HAS_SHARED_MEMORY
+    /*
+     * initializing cache if we don't already have a shm address
+     */
+    if (!st->cache_shm) {
+#endif
+        result = util_ldap_cache_init(p, st);
+        if (result != APR_SUCCESS) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, result, s, APLOGNO(01315)
+                         "LDAP cache: could not create shared memory segment");
+            return DONE;
+        }
+
+        result = ap_global_mutex_create(&st->util_ldap_cache_lock, NULL,
+                                        ldap_cache_mutex_type, NULL, s, p, 0);
+        if (result != APR_SUCCESS) {
+            return result;
+        }
+
+        /* merge config in all vhost */
+        s_vhost = s->next;
+        while (s_vhost) {
+            st_vhost = (util_ldap_state_t *)
+                       ap_get_module_config(s_vhost->module_config,
+                                            &ldap_module);
+            st_vhost->util_ldap_cache = st->util_ldap_cache;
+            st_vhost->util_ldap_cache_lock = st->util_ldap_cache_lock;
+#if APR_HAS_SHARED_MEMORY
+            st_vhost->cache_shm = st->cache_shm;
+            st_vhost->cache_rmm = st->cache_rmm;
+            st_vhost->cache_file = st->cache_file;
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, result, s, APLOGNO(01316)
+                         "LDAP merging Shared Cache conf: shm=0x%pp rmm=0x%pp "
+                         "for VHOST: %s", st->cache_shm, st->cache_rmm,
+                         s_vhost->server_hostname);
+#endif
+            s_vhost = s_vhost->next;
+        }
+#if APR_HAS_SHARED_MEMORY
+    }
+    else {
+        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01317)
+                     "LDAP cache: LDAPSharedCacheSize is zero, disabling "
+                     "shared memory cache");
+    }
+#endif
+
+    /* log the LDAP SDK used
+     */
+    {
+        apr_ldap_err_t *result = NULL;
+        apr_ldap_info(p, &(result));
+        if (result != NULL) {
+            ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(01318) "%s", result->reason);
+        }
+    }
+
+    apr_pool_cleanup_register(p, s, util_ldap_cleanup_module,
+                              util_ldap_cleanup_module);
+
+    /*
+     * Initialize SSL support, and log the result for the benefit of the admin.
+     *
+     * If SSL is not supported it is not necessarily an error, as the
+     * application may not want to use it.
+     */
+    rc = apr_ldap_ssl_init(p,
+                      NULL,
+                      0,
+                      &(result_err));
+    if (APR_SUCCESS == rc) {
+        rc = apr_ldap_set_option(ptemp, NULL, APR_LDAP_OPT_TLS_CERT,
+                                 (void *)st->global_certs, &(result_err));
+    }
+
+    if (APR_SUCCESS == rc) {
+        st->ssl_supported = 1;
+        ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(01319)
+                     "LDAP: SSL support available" );
+    }
+    else {
+        st->ssl_supported = 0;
+        ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(01320)
+                     "LDAP: SSL support unavailable%s%s",
+                     result_err ? ": " : "",
+                     result_err ? result_err->reason : "");
+    }
+
+    /* ssl_supported is really a global setting */
+    s_vhost = s->next;
+    while (s_vhost) {
+        st_vhost = (util_ldap_state_t *)
+                   ap_get_module_config(s_vhost->module_config,
+                                        &ldap_module);
+
+        st_vhost->ssl_supported = st->ssl_supported;
+        s_vhost = s_vhost->next;
+    }
+
+    /* Initialize the rebind callback's cross reference list. */
+    apr_ldap_rebind_init (p);
+
+#ifdef AP_LDAP_OPT_DEBUG
+    if (st->debug_level > 0) {
+        result = ldap_set_option(NULL, AP_LDAP_OPT_DEBUG, &st->debug_level);
+        if (result != LDAP_SUCCESS) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01321)
+                    "LDAP: Could not set the LDAP library debug level to %d:(%d) %s",
+                    st->debug_level, result, ldap_err2string(result));
+        }
+    }
+#endif
+
+    return(OK);
+}
+
+static void util_ldap_child_init(apr_pool_t *p, server_rec *s)
+{
+    apr_status_t sts;
+    util_ldap_state_t *st = ap_get_module_config(s->module_config,
+                                                 &ldap_module);
+
+    if (!st->util_ldap_cache_lock) return;
+
+    sts = apr_global_mutex_child_init(&st->util_ldap_cache_lock,
+              apr_global_mutex_lockfile(st->util_ldap_cache_lock), p);
+    if (sts != APR_SUCCESS) {
+        ap_log_error(APLOG_MARK, APLOG_CRIT, sts, s, APLOGNO(01322)
+                     "Failed to initialise global mutex %s in child process",
+                     ldap_cache_mutex_type);
+    }
+}
+
+static const command_rec util_ldap_cmds[] = {
+    AP_INIT_TAKE1("LDAPSharedCacheSize", util_ldap_set_cache_bytes,
+                  NULL, RSRC_CONF,
+                  "Set the size of the shared memory cache (in bytes). Use "
+                  "0 to disable the shared memory cache. (default: 500000)"),
+
+    AP_INIT_TAKE1("LDAPSharedCacheFile", util_ldap_set_cache_file,
+                  NULL, RSRC_CONF,
+                  "Set the file name for the shared memory cache."),
+
+    AP_INIT_TAKE1("LDAPCacheEntries", util_ldap_set_cache_entries,
+                  NULL, RSRC_CONF,
+                  "Set the maximum number of entries that are possible in the "
+                  "LDAP search cache. Use 0 or -1 to disable the search cache "
+                  "(default: 1024)"),
+
+    AP_INIT_TAKE1("LDAPCacheTTL", util_ldap_set_cache_ttl,
+                  NULL, RSRC_CONF,
+                  "Set the maximum time (in seconds) that an item can be "
+                  "cached in the LDAP search cache. Use 0 for no limit. "
+                  "(default 600)"),
+
+    AP_INIT_TAKE1("LDAPOpCacheEntries", util_ldap_set_opcache_entries,
+                  NULL, RSRC_CONF,
+                  "Set the maximum number of entries that are possible "
+                  "in the LDAP compare cache. Use 0 or -1 to disable the compare cache "
+                  "(default: 1024)"),
+
+    AP_INIT_TAKE1("LDAPOpCacheTTL", util_ldap_set_opcache_ttl,
+                  NULL, RSRC_CONF,
+                  "Set the maximum time (in seconds) that an item is cached "
+                  "in the LDAP operation cache. Use 0 for no limit. "
+                  "(default: 600)"),
+
+    AP_INIT_TAKE23("LDAPTrustedGlobalCert", util_ldap_set_trusted_global_cert,
+                   NULL, RSRC_CONF,
+                   "Takes three arguments; the first argument is the cert "
+                   "type of the second argument, one of CA_DER, CA_BASE64, "
+                   "CA_CERT7_DB, CA_SECMOD, CERT_DER, CERT_BASE64, CERT_KEY3_DB, "
+                   "CERT_NICKNAME, KEY_DER, or KEY_BASE64. The second argument "
+                   "specifes the file and/or directory containing the trusted CA "
+                   "certificates (and global client certs for Netware) used to "
+                   "validate the LDAP server. The third argument is an optional "
+                   "passphrase if applicable."),
+
+    AP_INIT_TAKE23("LDAPTrustedClientCert", util_ldap_set_trusted_client_cert,
+                   NULL, OR_AUTHCFG,
+                   "Takes three arguments: the first argument is the certificate "
+                   "type of the second argument, one of CA_DER, CA_BASE64, "
+                   "CA_CERT7_DB, CA_SECMOD, CERT_DER, CERT_BASE64, CERT_KEY3_DB, "
+                   "CERT_NICKNAME, KEY_DER, or KEY_BASE64. The second argument "
+                   "specifies the file and/or directory containing the client "
+                   "certificate, or certificate ID used to validate this LDAP "
+                   "client.  The third argument is an optional passphrase if "
+                   "applicable."),
+
+    AP_INIT_TAKE1("LDAPTrustedMode", util_ldap_set_trusted_mode,
+                  NULL, RSRC_CONF,
+                  "Specify the type of security that should be applied to "
+                  "an LDAP connection. One of; NONE, SSL or STARTTLS."),
+
+    AP_INIT_FLAG("LDAPVerifyServerCert", util_ldap_set_verify_srv_cert,
+                  NULL, RSRC_CONF,
+                  "Set to 'ON' requires that the server certificate be verified"
+                  " before a secure LDAP connection can be establish.  Default"
+                  " 'ON'"),
+
+    AP_INIT_TAKE1("LDAPConnectionTimeout", util_ldap_set_connection_timeout,
+                  NULL, RSRC_CONF,
+                  "Specify the LDAP socket connection timeout in seconds "
+                  "(default: 10)"),
+
+    AP_INIT_TAKE1("LDAPReferrals", util_ldap_set_chase_referrals,
+                  NULL, OR_AUTHCFG,
+                  "Choose whether referrals are chased ['ON'|'OFF'|'DEFAULT'].  Default 'ON'"),
+
+    AP_INIT_TAKE1("LDAPReferralHopLimit", util_ldap_set_referral_hop_limit,
+                  NULL, OR_AUTHCFG,
+                  "Limit the number of referral hops that LDAP can follow. "
+                  "(Integer value, Consult LDAP SDK documentation for applicability and defaults"),
+
+    AP_INIT_TAKE1("LDAPLibraryDebug", util_ldap_set_debug_level,
+                  NULL, RSRC_CONF,
+                  "Enable debugging in LDAP SDK (Default: off, values: SDK specific"),
+
+    AP_INIT_TAKE1("LDAPTimeout", util_ldap_set_op_timeout,
+                  NULL, RSRC_CONF,
+                  "Specify the LDAP bind/search timeout in seconds "
+                  "(0 = no limit). Default: 60"),
+    AP_INIT_TAKE1("LDAPConnectionPoolTTL", util_ldap_set_conn_ttl,
+                  NULL, RSRC_CONF,
+                  "Specify the maximum amount of time a bound connection can sit "
+                  "idle and still be considered valid for reuse"
+                  "(0 = no pool, -1 = no limit, n = time in seconds). Default: -1"),
+    AP_INIT_TAKE1("LDAPRetries", util_ldap_set_retries,
+                  NULL, RSRC_CONF,
+                  "Specify the number of times a failed LDAP operation should be retried "
+                  "(0 = no retries). Default: 3"),
+    AP_INIT_TAKE1("LDAPRetryDelay", util_ldap_set_retry_delay,
+                  NULL, RSRC_CONF,
+                  "Specify the delay between retries of a failed LDAP operation "
+                  "(0 = no delay). Default: 0"),
+
+
+    {NULL}
+};
+
+static void util_ldap_register_hooks(apr_pool_t *p)
+{
+    APR_REGISTER_OPTIONAL_FN(uldap_connection_open);
+    APR_REGISTER_OPTIONAL_FN(uldap_connection_close);
+    APR_REGISTER_OPTIONAL_FN(uldap_connection_unbind);
+    APR_REGISTER_OPTIONAL_FN(uldap_connection_find);
+    APR_REGISTER_OPTIONAL_FN(uldap_cache_comparedn);
+    APR_REGISTER_OPTIONAL_FN(uldap_cache_compare);
+    APR_REGISTER_OPTIONAL_FN(uldap_cache_checkuserid);
+    APR_REGISTER_OPTIONAL_FN(uldap_cache_getuserdn);
+    APR_REGISTER_OPTIONAL_FN(uldap_ssl_supported);
+    APR_REGISTER_OPTIONAL_FN(uldap_cache_check_subgroups);
+
+    ap_hook_pre_config(util_ldap_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_post_config(util_ldap_post_config,NULL,NULL,APR_HOOK_MIDDLE);
+    ap_hook_handler(util_ldap_handler, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_child_init(util_ldap_child_init, NULL, NULL, APR_HOOK_MIDDLE);
+}
+
+AP_DECLARE_MODULE(ldap) = {
+   STANDARD20_MODULE_STUFF,
+   util_ldap_create_dir_config, /* create dir config */
+   NULL,                        /* merge dir config */
+   util_ldap_create_config,     /* create server config */
+   util_ldap_merge_config,      /* merge server config */
+   util_ldap_cmds,              /* command table */
+   util_ldap_register_hooks,    /* set up request processing hooks */
+};