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-rw-r--r--modules/aaa/mod_authn_socache.c475
1 files changed, 475 insertions, 0 deletions
diff --git a/modules/aaa/mod_authn_socache.c b/modules/aaa/mod_authn_socache.c
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+++ b/modules/aaa/mod_authn_socache.c
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+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "apr_strings.h"
+#include "apr_md5.h" /* for apr_password_validate */
+
+#include "ap_config.h"
+#include "ap_provider.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "http_core.h"
+#include "http_log.h"
+#include "http_protocol.h"
+#include "http_request.h"
+
+#include "mod_auth.h"
+
+#include "ap_socache.h"
+#include "util_mutex.h"
+#include "apr_optional.h"
+
+module AP_MODULE_DECLARE_DATA authn_socache_module;
+
+typedef struct authn_cache_dircfg {
+ apr_interval_time_t timeout;
+ apr_array_header_t *providers;
+ const char *context;
+} authn_cache_dircfg;
+
+/* FIXME:
+ * I think the cache and mutex should be global
+ */
+static apr_global_mutex_t *authn_cache_mutex = NULL;
+static ap_socache_provider_t *socache_provider = NULL;
+static ap_socache_instance_t *socache_instance = NULL;
+static const char *const authn_cache_id = "authn-socache";
+static int configured;
+
+static apr_status_t remove_lock(void *data)
+{
+ if (authn_cache_mutex) {
+ apr_global_mutex_destroy(authn_cache_mutex);
+ authn_cache_mutex = NULL;
+ }
+ return APR_SUCCESS;
+}
+
+static apr_status_t destroy_cache(void *data)
+{
+ if (socache_instance) {
+ socache_provider->destroy(socache_instance, (server_rec*)data);
+ socache_instance = NULL;
+ }
+ return APR_SUCCESS;
+}
+
+static int authn_cache_precfg(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptmp)
+{
+ apr_status_t rv = ap_mutex_register(pconf, authn_cache_id,
+ NULL, APR_LOCK_DEFAULT, 0);
+ if (rv != APR_SUCCESS) {
+ ap_log_perror(APLOG_MARK, APLOG_CRIT, rv, plog, APLOGNO(01673)
+ "failed to register %s mutex", authn_cache_id);
+ return 500; /* An HTTP status would be a misnomer! */
+ }
+ socache_provider = ap_lookup_provider(AP_SOCACHE_PROVIDER_GROUP,
+ AP_SOCACHE_DEFAULT_PROVIDER,
+ AP_SOCACHE_PROVIDER_VERSION);
+ configured = 0;
+ return OK;
+}
+
+static int authn_cache_post_config(apr_pool_t *pconf, apr_pool_t *plog,
+ apr_pool_t *ptmp, server_rec *s)
+{
+ apr_status_t rv;
+ static struct ap_socache_hints authn_cache_hints = {64, 32, 60000000};
+ const char *errmsg;
+
+ if (!configured) {
+ return OK; /* don't waste the overhead of creating mutex & cache */
+ }
+ if (socache_provider == NULL) {
+ ap_log_perror(APLOG_MARK, APLOG_CRIT, 0, plog, APLOGNO(01674)
+ "Please select a socache provider with AuthnCacheSOCache "
+ "(no default found on this platform). Maybe you need to "
+ "load mod_socache_shmcb or another socache module first");
+ return 500; /* An HTTP status would be a misnomer! */
+ }
+
+ /* We have socache_provider, but do not have socache_instance. This should
+ * happen only when using "default" socache_provider, so create default
+ * socache_instance in this case. */
+ if (socache_instance == NULL) {
+ errmsg = socache_provider->create(&socache_instance, NULL,
+ ptmp, pconf);
+ if (errmsg) {
+ ap_log_perror(APLOG_MARK, APLOG_CRIT, 0, plog, APLOGNO(02612)
+ "failed to create mod_socache_shmcb socache "
+ "instance: %s", errmsg);
+ return 500;
+ }
+ }
+
+ rv = ap_global_mutex_create(&authn_cache_mutex, NULL,
+ authn_cache_id, NULL, s, pconf, 0);
+ if (rv != APR_SUCCESS) {
+ ap_log_perror(APLOG_MARK, APLOG_CRIT, rv, plog, APLOGNO(01675)
+ "failed to create %s mutex", authn_cache_id);
+ return 500; /* An HTTP status would be a misnomer! */
+ }
+ apr_pool_cleanup_register(pconf, NULL, remove_lock, apr_pool_cleanup_null);
+
+ rv = socache_provider->init(socache_instance, authn_cache_id,
+ &authn_cache_hints, s, pconf);
+ if (rv != APR_SUCCESS) {
+ ap_log_perror(APLOG_MARK, APLOG_CRIT, rv, plog, APLOGNO(01677)
+ "failed to initialise %s cache", authn_cache_id);
+ return 500; /* An HTTP status would be a misnomer! */
+ }
+ apr_pool_cleanup_register(pconf, (void*)s, destroy_cache, apr_pool_cleanup_null);
+ return OK;
+}
+
+static void authn_cache_child_init(apr_pool_t *p, server_rec *s)
+{
+ const char *lock;
+ apr_status_t rv;
+ if (!configured) {
+ return; /* don't waste the overhead of creating mutex & cache */
+ }
+ lock = apr_global_mutex_lockfile(authn_cache_mutex);
+ rv = apr_global_mutex_child_init(&authn_cache_mutex, lock, p);
+ if (rv != APR_SUCCESS) {
+ ap_log_error(APLOG_MARK, APLOG_CRIT, rv, s, APLOGNO(01678)
+ "failed to initialise mutex in child_init");
+ }
+}
+
+static const char *authn_cache_socache(cmd_parms *cmd, void *CFG,
+ const char *arg)
+{
+ const char *errmsg = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+ const char *sep, *name;
+
+ if (errmsg)
+ return errmsg;
+
+ /* Argument is of form 'name:args' or just 'name'. */
+ sep = ap_strchr_c(arg, ':');
+ if (sep) {
+ name = apr_pstrmemdup(cmd->pool, arg, sep - arg);
+ sep++;
+ }
+ else {
+ name = arg;
+ }
+
+ socache_provider = ap_lookup_provider(AP_SOCACHE_PROVIDER_GROUP, name,
+ AP_SOCACHE_PROVIDER_VERSION);
+ if (socache_provider == NULL) {
+ errmsg = apr_psprintf(cmd->pool,
+ "Unknown socache provider '%s'. Maybe you need "
+ "to load the appropriate socache module "
+ "(mod_socache_%s?)", arg, arg);
+ }
+ else {
+ errmsg = socache_provider->create(&socache_instance, sep,
+ cmd->temp_pool, cmd->pool);
+ }
+
+ if (errmsg) {
+ errmsg = apr_psprintf(cmd->pool, "AuthnCacheSOCache: %s", errmsg);
+ }
+ return errmsg;
+}
+
+static const char *authn_cache_enable(cmd_parms *cmd, void *CFG)
+{
+ const char *errmsg = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+ configured = 1;
+ return errmsg;
+}
+
+static const char *const directory = "directory";
+static void* authn_cache_dircfg_create(apr_pool_t *pool, char *s)
+{
+ authn_cache_dircfg *ret = apr_palloc(pool, sizeof(authn_cache_dircfg));
+ ret->timeout = apr_time_from_sec(300);
+ ret->providers = NULL;
+ ret->context = directory;
+ return ret;
+}
+
+/* not sure we want this. Might be safer to document use-all-or-none */
+static void* authn_cache_dircfg_merge(apr_pool_t *pool, void *BASE, void *ADD)
+{
+ authn_cache_dircfg *base = BASE;
+ authn_cache_dircfg *add = ADD;
+ authn_cache_dircfg *ret = apr_pmemdup(pool, add, sizeof(authn_cache_dircfg));
+ /* preserve context and timeout if not defaults */
+ if (add->context == directory) {
+ ret->context = base->context;
+ }
+ if (add->timeout == apr_time_from_sec(300)) {
+ ret->timeout = base->timeout;
+ }
+ if (add->providers == NULL) {
+ ret->providers = base->providers;
+ }
+ return ret;
+}
+
+static const char *authn_cache_setprovider(cmd_parms *cmd, void *CFG,
+ const char *arg)
+{
+ authn_cache_dircfg *cfg = CFG;
+ if (cfg->providers == NULL) {
+ cfg->providers = apr_array_make(cmd->pool, 4, sizeof(const char*));
+ }
+ APR_ARRAY_PUSH(cfg->providers, const char*) = arg;
+ configured = 1;
+ return NULL;
+}
+
+static const char *authn_cache_timeout(cmd_parms *cmd, void *CFG,
+ const char *arg)
+{
+ authn_cache_dircfg *cfg = CFG;
+ int secs = atoi(arg);
+ cfg->timeout = apr_time_from_sec(secs);
+ return NULL;
+}
+
+static const command_rec authn_cache_cmds[] =
+{
+ /* global stuff: cache and mutex */
+ AP_INIT_TAKE1("AuthnCacheSOCache", authn_cache_socache, NULL, RSRC_CONF,
+ "socache provider for authn cache"),
+ AP_INIT_NO_ARGS("AuthnCacheEnable", authn_cache_enable, NULL, RSRC_CONF,
+ "enable socache configuration in htaccess even if not enabled anywhere else"),
+ /* per-dir stuff */
+ AP_INIT_ITERATE("AuthnCacheProvideFor", authn_cache_setprovider, NULL,
+ OR_AUTHCFG, "Determine what authn providers to cache for"),
+ AP_INIT_TAKE1("AuthnCacheTimeout", authn_cache_timeout, NULL,
+ OR_AUTHCFG, "Timeout (secs) for cached credentials"),
+ AP_INIT_TAKE1("AuthnCacheContext", ap_set_string_slot,
+ (void*)APR_OFFSETOF(authn_cache_dircfg, context),
+ ACCESS_CONF, "Context for authn cache"),
+ {NULL}
+};
+
+static const char *construct_key(request_rec *r, const char *context,
+ const char *user, const char *realm)
+{
+ /* handle "special" context values */
+ if (!strcmp(context, directory)) {
+ /* FIXME: are we at risk of this blowing up? */
+ char *new_context;
+ char *slash = strrchr(r->uri, '/');
+ new_context = apr_palloc(r->pool, slash - r->uri +
+ strlen(r->server->server_hostname) + 1);
+ strcpy(new_context, r->server->server_hostname);
+ strncat(new_context, r->uri, slash - r->uri);
+ context = new_context;
+ }
+ else if (!strcmp(context, "server")) {
+ context = r->server->server_hostname;
+ }
+ /* any other context value is literal */
+
+ if (realm == NULL) { /* basic auth */
+ return apr_pstrcat(r->pool, context, ":", user, NULL);
+ }
+ else { /* digest auth */
+ return apr_pstrcat(r->pool, context, ":", user, ":", realm, NULL);
+ }
+}
+
+static void ap_authn_cache_store(request_rec *r, const char *module,
+ const char *user, const char *realm,
+ const char* data)
+{
+ apr_status_t rv;
+ authn_cache_dircfg *dcfg;
+ const char *key;
+ apr_time_t expiry;
+
+ /* first check whether we're cacheing for this module */
+ dcfg = ap_get_module_config(r->per_dir_config, &authn_socache_module);
+ if (!configured || !dcfg->providers) {
+ return;
+ }
+ if (!ap_array_str_contains(dcfg->providers, module)) {
+ return;
+ }
+
+ /* OK, we're on. Grab mutex to do our business */
+ rv = apr_global_mutex_trylock(authn_cache_mutex);
+ if (APR_STATUS_IS_EBUSY(rv)) {
+ /* don't wait around; just abandon it */
+ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, rv, r, APLOGNO(01679)
+ "authn credentials for %s not cached (mutex busy)", user);
+ return;
+ }
+ else if (rv != APR_SUCCESS) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01680)
+ "Failed to cache authn credentials for %s in %s",
+ module, dcfg->context);
+ return;
+ }
+
+ /* We have the mutex, so go ahead */
+ /* first build our key and determine expiry time */
+ key = construct_key(r, dcfg->context, user, realm);
+ expiry = apr_time_now() + dcfg->timeout;
+
+ /* store it */
+ rv = socache_provider->store(socache_instance, r->server,
+ (unsigned char*)key, strlen(key), expiry,
+ (unsigned char*)data, strlen(data), r->pool);
+ if (rv == APR_SUCCESS) {
+ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01681)
+ "Cached authn credentials for %s in %s",
+ user, dcfg->context);
+ }
+ else {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01682)
+ "Failed to cache authn credentials for %s in %s",
+ module, dcfg->context);
+ }
+
+ /* We're done with the mutex */
+ rv = apr_global_mutex_unlock(authn_cache_mutex);
+ if (rv != APR_SUCCESS) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01683) "Failed to release mutex!");
+ }
+}
+
+#define MAX_VAL_LEN 100
+static authn_status check_password(request_rec *r, const char *user,
+ const char *password)
+{
+ /* construct key
+ * look it up
+ * if found, test password
+ *
+ * mutexing here would be a big performance drag.
+ * It's definitely unnecessary with some backends (like ndbm or gdbm)
+ * Is there a risk in the general case? I guess the only risk we
+ * care about is a race condition that gets us a dangling pointer
+ * to no-longer-defined memory. Hmmm ...
+ */
+ apr_status_t rv;
+ const char *key;
+ authn_cache_dircfg *dcfg;
+ unsigned char val[MAX_VAL_LEN];
+ unsigned int vallen = MAX_VAL_LEN - 1;
+ dcfg = ap_get_module_config(r->per_dir_config, &authn_socache_module);
+ if (!configured || !dcfg->providers) {
+ return AUTH_USER_NOT_FOUND;
+ }
+ key = construct_key(r, dcfg->context, user, NULL);
+ rv = socache_provider->retrieve(socache_instance, r->server,
+ (unsigned char*)key, strlen(key),
+ val, &vallen, r->pool);
+
+ if (APR_STATUS_IS_NOTFOUND(rv)) {
+ /* not found - just return */
+ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01684)
+ "Authn cache: no credentials found for %s", user);
+ return AUTH_USER_NOT_FOUND;
+ }
+ else if (rv == APR_SUCCESS) {
+ /* OK, we got a value */
+ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01685)
+ "Authn cache: found credentials for %s", user);
+ val[vallen] = 0;
+ }
+ else {
+ /* error: give up and pass the buck */
+ /* FIXME: getting this for NOTFOUND - prolly a bug in mod_socache */
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01686)
+ "Error accessing authentication cache");
+ return AUTH_USER_NOT_FOUND;
+ }
+
+ rv = apr_password_validate(password, (char*) val);
+ if (rv != APR_SUCCESS) {
+ return AUTH_DENIED;
+ }
+
+ return AUTH_GRANTED;
+}
+
+static authn_status get_realm_hash(request_rec *r, const char *user,
+ const char *realm, char **rethash)
+{
+ apr_status_t rv;
+ const char *key;
+ authn_cache_dircfg *dcfg;
+ unsigned char val[MAX_VAL_LEN];
+ unsigned int vallen = MAX_VAL_LEN - 1;
+ dcfg = ap_get_module_config(r->per_dir_config, &authn_socache_module);
+ if (!configured || !dcfg->providers) {
+ return AUTH_USER_NOT_FOUND;
+ }
+ key = construct_key(r, dcfg->context, user, realm);
+ rv = socache_provider->retrieve(socache_instance, r->server,
+ (unsigned char*)key, strlen(key),
+ val, &vallen, r->pool);
+
+ if (APR_STATUS_IS_NOTFOUND(rv)) {
+ /* not found - just return */
+ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01687)
+ "Authn cache: no credentials found for %s", user);
+ return AUTH_USER_NOT_FOUND;
+ }
+ else if (rv == APR_SUCCESS) {
+ /* OK, we got a value */
+ ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01688)
+ "Authn cache: found credentials for %s", user);
+ }
+ else {
+ /* error: give up and pass the buck */
+ /* FIXME: getting this for NOTFOUND - prolly a bug in mod_socache */
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01689)
+ "Error accessing authentication cache");
+ return AUTH_USER_NOT_FOUND;
+ }
+ *rethash = apr_pstrmemdup(r->pool, (char *)val, vallen);
+
+ return AUTH_USER_FOUND;
+}
+
+static const authn_provider authn_cache_provider =
+{
+ &check_password,
+ &get_realm_hash,
+};
+
+static void register_hooks(apr_pool_t *p)
+{
+ ap_register_auth_provider(p, AUTHN_PROVIDER_GROUP, "socache",
+ AUTHN_PROVIDER_VERSION,
+ &authn_cache_provider, AP_AUTH_INTERNAL_PER_CONF);
+ APR_REGISTER_OPTIONAL_FN(ap_authn_cache_store);
+ ap_hook_pre_config(authn_cache_precfg, NULL, NULL, APR_HOOK_MIDDLE);
+ ap_hook_post_config(authn_cache_post_config, NULL, NULL, APR_HOOK_MIDDLE);
+ ap_hook_child_init(authn_cache_child_init, NULL, NULL, APR_HOOK_MIDDLE);
+}
+
+AP_DECLARE_MODULE(authn_socache) =
+{
+ STANDARD20_MODULE_STUFF,
+ authn_cache_dircfg_create,
+ authn_cache_dircfg_merge,
+ NULL,
+ NULL,
+ authn_cache_cmds,
+ register_hooks
+};