/* 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
};