diff options
Diffstat (limited to 'modules/aaa/mod_auth_digest.c')
| -rw-r--r-- | modules/aaa/mod_auth_digest.c | 1983 |
1 files changed, 1983 insertions, 0 deletions
diff --git a/modules/aaa/mod_auth_digest.c b/modules/aaa/mod_auth_digest.c new file mode 100644 index 0000000..791cec2 --- /dev/null +++ b/modules/aaa/mod_auth_digest.c @@ -0,0 +1,1983 @@ +/* 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. + */ + +/* + * mod_auth_digest: MD5 digest authentication + * + * Originally by Alexei Kosut <akosut@nueva.pvt.k12.ca.us> + * Updated to RFC-2617 by Ronald Tschal�r <ronald@innovation.ch> + * based on mod_auth, by Rob McCool and Robert S. Thau + * + * This module an updated version of modules/standard/mod_digest.c + * It is still fairly new and problems may turn up - submit problem + * reports to the Apache bug-database, or send them directly to me + * at ronald@innovation.ch. + * + * Open Issues: + * - qop=auth-int (when streams and trailer support available) + * - nonce-format configurability + * - Proxy-Authorization-Info header is set by this module, but is + * currently ignored by mod_proxy (needs patch to mod_proxy) + * - The source of the secret should be run-time directive (with server + * scope: RSRC_CONF) + * - shared-mem not completely tested yet. Seems to work ok for me, + * but... (definitely won't work on Windoze) + * - Sharing a realm among multiple servers has following problems: + * o Server name and port can't be included in nonce-hash + * (we need two nonce formats, which must be configured explicitly) + * o Nonce-count check can't be for equal, or then nonce-count checking + * must be disabled. What we could do is the following: + * (expected < received) ? set expected = received : issue error + * The only problem is that it allows replay attacks when somebody + * captures a packet sent to one server and sends it to another + * one. Should we add "AuthDigestNcCheck Strict"? + * - expired nonces give amaya fits. + * - MD5-sess and auth-int are not yet implemented. An incomplete + * implementation has been removed and can be retrieved from svn history. + */ + +#include "apr_sha1.h" +#include "apr_base64.h" +#include "apr_lib.h" +#include "apr_time.h" +#include "apr_errno.h" +#include "apr_global_mutex.h" +#include "apr_strings.h" + +#define APR_WANT_STRFUNC +#include "apr_want.h" + +#include "ap_config.h" +#include "httpd.h" +#include "http_config.h" +#include "http_core.h" +#include "http_request.h" +#include "http_log.h" +#include "http_protocol.h" +#include "apr_uri.h" +#include "util_md5.h" +#include "util_mutex.h" +#include "apr_shm.h" +#include "apr_rmm.h" +#include "ap_provider.h" + +#include "mod_auth.h" + +#if APR_HAVE_UNISTD_H +#include <unistd.h> +#endif + +/* struct to hold the configuration info */ + +typedef struct digest_config_struct { + const char *dir_name; + authn_provider_list *providers; + const char *realm; + apr_array_header_t *qop_list; + apr_sha1_ctx_t nonce_ctx; + apr_time_t nonce_lifetime; + int check_nc; + const char *algorithm; + char *uri_list; +} digest_config_rec; + + +#define DFLT_ALGORITHM "MD5" + +#define DFLT_NONCE_LIFE apr_time_from_sec(300) +#define NEXTNONCE_DELTA apr_time_from_sec(30) + + +#define NONCE_TIME_LEN (((sizeof(apr_time_t)+2)/3)*4) +#define NONCE_HASH_LEN (2*APR_SHA1_DIGESTSIZE) +#define NONCE_LEN (int )(NONCE_TIME_LEN + NONCE_HASH_LEN) + +#define SECRET_LEN 20 +#define RETAINED_DATA_ID "mod_auth_digest" + + +/* client list definitions */ + +typedef struct hash_entry { + unsigned long key; /* the key for this entry */ + struct hash_entry *next; /* next entry in the bucket */ + unsigned long nonce_count; /* for nonce-count checking */ + char last_nonce[NONCE_LEN+1]; /* for one-time nonce's */ +} client_entry; + +static struct hash_table { + client_entry **table; + unsigned long tbl_len; + unsigned long num_entries; + unsigned long num_created; + unsigned long num_removed; + unsigned long num_renewed; +} *client_list; + + +/* struct to hold a parsed Authorization header */ + +enum hdr_sts { NO_HEADER, NOT_DIGEST, INVALID, VALID }; + +typedef struct digest_header_struct { + const char *scheme; + const char *realm; + const char *username; + char *nonce; + const char *uri; + const char *method; + const char *digest; + const char *algorithm; + const char *cnonce; + const char *opaque; + unsigned long opaque_num; + const char *message_qop; + const char *nonce_count; + /* the following fields are not (directly) from the header */ + const char *raw_request_uri; + apr_uri_t *psd_request_uri; + apr_time_t nonce_time; + enum hdr_sts auth_hdr_sts; + int needed_auth; + const char *ha1; + client_entry *client; +} digest_header_rec; + + +/* (mostly) nonce stuff */ + +typedef union time_union { + apr_time_t time; + unsigned char arr[sizeof(apr_time_t)]; +} time_rec; + +static unsigned char *secret; + +/* client-list, opaque, and one-time-nonce stuff */ + +static apr_shm_t *client_shm = NULL; +static apr_rmm_t *client_rmm = NULL; +static unsigned long *opaque_cntr; +static apr_time_t *otn_counter; /* one-time-nonce counter */ +static apr_global_mutex_t *client_lock = NULL; +static apr_global_mutex_t *opaque_lock = NULL; +static const char *client_mutex_type = "authdigest-client"; +static const char *opaque_mutex_type = "authdigest-opaque"; +static const char *client_shm_filename; + +#define DEF_SHMEM_SIZE 1000L /* ~ 12 entries */ +#define DEF_NUM_BUCKETS 15L +#define HASH_DEPTH 5 + +static apr_size_t shmem_size = DEF_SHMEM_SIZE; +static unsigned long num_buckets = DEF_NUM_BUCKETS; + + +module AP_MODULE_DECLARE_DATA auth_digest_module; + +/* + * initialization code + */ + +static apr_status_t cleanup_tables(void *not_used) +{ + ap_log_error(APLOG_MARK, APLOG_INFO, 0, NULL, APLOGNO(01756) + "cleaning up shared memory"); + + if (client_rmm) { + apr_rmm_destroy(client_rmm); + client_rmm = NULL; + } + + if (client_shm) { + apr_shm_destroy(client_shm); + client_shm = NULL; + } + + if (client_lock) { + apr_global_mutex_destroy(client_lock); + client_lock = NULL; + } + + if (opaque_lock) { + apr_global_mutex_destroy(opaque_lock); + opaque_lock = NULL; + } + + client_list = NULL; + + return APR_SUCCESS; +} + +static void log_error_and_cleanup(char *msg, apr_status_t sts, server_rec *s) +{ + ap_log_error(APLOG_MARK, APLOG_ERR, sts, s, APLOGNO(01760) + "%s - all nonce-count checking and one-time nonces " + "disabled", msg); + + cleanup_tables(NULL); +} + +/* RMM helper functions that behave like single-step malloc/free. */ + +static void *rmm_malloc(apr_rmm_t *rmm, apr_size_t size) +{ + apr_rmm_off_t offset = apr_rmm_malloc(rmm, size); + + if (!offset) { + return NULL; + } + + return apr_rmm_addr_get(rmm, offset); +} + +static apr_status_t rmm_free(apr_rmm_t *rmm, void *alloc) +{ + apr_rmm_off_t offset = apr_rmm_offset_get(rmm, alloc); + + return apr_rmm_free(rmm, offset); +} + +#if APR_HAS_SHARED_MEMORY + +static int initialize_tables(server_rec *s, apr_pool_t *ctx) +{ + unsigned long idx; + apr_status_t sts; + + /* set up client list */ + + /* Create the shared memory segment */ + + client_shm = NULL; + client_rmm = NULL; + client_lock = NULL; + opaque_lock = NULL; + client_list = NULL; + + /* + * Create a unique filename using our pid. This information is + * stashed in the global variable so the children inherit it. + */ + client_shm_filename = ap_runtime_dir_relative(ctx, "authdigest_shm"); + client_shm_filename = ap_append_pid(ctx, client_shm_filename, "."); + + /* Use anonymous shm by default, fall back on name-based. */ + sts = apr_shm_create(&client_shm, shmem_size, NULL, ctx); + if (APR_STATUS_IS_ENOTIMPL(sts)) { + /* For a name-based segment, remove it first in case of a + * previous unclean shutdown. */ + apr_shm_remove(client_shm_filename, ctx); + + /* Now create that segment */ + sts = apr_shm_create(&client_shm, shmem_size, + client_shm_filename, ctx); + } + + if (APR_SUCCESS != sts) { + ap_log_error(APLOG_MARK, APLOG_ERR, sts, s, APLOGNO(01762) + "Failed to create shared memory segment on file %s", + client_shm_filename); + log_error_and_cleanup("failed to initialize shm", sts, s); + return HTTP_INTERNAL_SERVER_ERROR; + } + + sts = apr_rmm_init(&client_rmm, + NULL, /* no lock, we'll do the locking ourselves */ + apr_shm_baseaddr_get(client_shm), + shmem_size, ctx); + if (sts != APR_SUCCESS) { + log_error_and_cleanup("failed to initialize rmm", sts, s); + return !OK; + } + + client_list = rmm_malloc(client_rmm, sizeof(*client_list) + + sizeof(client_entry *) * num_buckets); + if (!client_list) { + log_error_and_cleanup("failed to allocate shared memory", -1, s); + return !OK; + } + client_list->table = (client_entry**) (client_list + 1); + for (idx = 0; idx < num_buckets; idx++) { + client_list->table[idx] = NULL; + } + client_list->tbl_len = num_buckets; + client_list->num_entries = 0; + + sts = ap_global_mutex_create(&client_lock, NULL, client_mutex_type, NULL, + s, ctx, 0); + if (sts != APR_SUCCESS) { + log_error_and_cleanup("failed to create lock (client_lock)", sts, s); + return !OK; + } + + + /* setup opaque */ + + opaque_cntr = rmm_malloc(client_rmm, sizeof(*opaque_cntr)); + if (opaque_cntr == NULL) { + log_error_and_cleanup("failed to allocate shared memory", -1, s); + return !OK; + } + *opaque_cntr = 1UL; + + sts = ap_global_mutex_create(&opaque_lock, NULL, opaque_mutex_type, NULL, + s, ctx, 0); + if (sts != APR_SUCCESS) { + log_error_and_cleanup("failed to create lock (opaque_lock)", sts, s); + return !OK; + } + + + /* setup one-time-nonce counter */ + + otn_counter = rmm_malloc(client_rmm, sizeof(*otn_counter)); + if (otn_counter == NULL) { + log_error_and_cleanup("failed to allocate shared memory", -1, s); + return !OK; + } + *otn_counter = 0; + /* no lock here */ + + + /* success */ + return OK; +} + +#endif /* APR_HAS_SHARED_MEMORY */ + +static int pre_init(apr_pool_t *pconf, apr_pool_t *plog, apr_pool_t *ptemp) +{ + apr_status_t rv; + void *retained; + + rv = ap_mutex_register(pconf, client_mutex_type, NULL, APR_LOCK_DEFAULT, 0); + if (rv != APR_SUCCESS) + return !OK; + rv = ap_mutex_register(pconf, opaque_mutex_type, NULL, APR_LOCK_DEFAULT, 0); + if (rv != APR_SUCCESS) + return !OK; + + retained = ap_retained_data_get(RETAINED_DATA_ID); + if (retained == NULL) { + retained = ap_retained_data_create(RETAINED_DATA_ID, SECRET_LEN); + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL, APLOGNO(01757) + "generating secret for digest authentication"); +#if APR_HAS_RANDOM + rv = apr_generate_random_bytes(retained, SECRET_LEN); +#else +#error APR random number support is missing +#endif + if (rv != APR_SUCCESS) { + ap_log_error(APLOG_MARK, APLOG_CRIT, rv, NULL, APLOGNO(01758) + "error generating secret"); + return !OK; + } + } + secret = retained; + return OK; +} + +static int initialize_module(apr_pool_t *p, apr_pool_t *plog, + apr_pool_t *ptemp, server_rec *s) +{ + /* initialize_module() will be called twice, and if it's a DSO + * then all static data from the first call will be lost. Only + * set up our static data on the second call. */ + if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_PRE_CONFIG) + return OK; + +#if APR_HAS_SHARED_MEMORY + /* Note: this stuff is currently fixed for the lifetime of the server, + * i.e. even across restarts. This means that A) any shmem-size + * configuration changes are ignored, and B) certain optimizations, + * such as only allocating the smallest necessary entry for each + * client, can't be done. However, the alternative is a nightmare: + * we can't call apr_shm_destroy on a graceful restart because there + * will be children using the tables, and we also don't know when the + * last child dies. Therefore we can never clean up the old stuff, + * creating a creeping memory leak. + */ + if (initialize_tables(s, p) != OK) { + return !OK; + } +#endif /* APR_HAS_SHARED_MEMORY */ + return OK; +} + +static void initialize_child(apr_pool_t *p, server_rec *s) +{ + apr_status_t sts; + + if (!client_shm) { + return; + } + + /* Get access to rmm in child */ + sts = apr_rmm_attach(&client_rmm, + NULL, + apr_shm_baseaddr_get(client_shm), + p); + if (sts != APR_SUCCESS) { + log_error_and_cleanup("failed to attach to rmm", sts, s); + return; + } + + sts = apr_global_mutex_child_init(&client_lock, + apr_global_mutex_lockfile(client_lock), + p); + if (sts != APR_SUCCESS) { + log_error_and_cleanup("failed to create lock (client_lock)", sts, s); + return; + } + sts = apr_global_mutex_child_init(&opaque_lock, + apr_global_mutex_lockfile(opaque_lock), + p); + if (sts != APR_SUCCESS) { + log_error_and_cleanup("failed to create lock (opaque_lock)", sts, s); + return; + } +} + +/* + * configuration code + */ + +static void *create_digest_dir_config(apr_pool_t *p, char *dir) +{ + digest_config_rec *conf; + + if (dir == NULL) { + return NULL; + } + + conf = (digest_config_rec *) apr_pcalloc(p, sizeof(digest_config_rec)); + if (conf) { + conf->qop_list = apr_array_make(p, 2, sizeof(char *)); + conf->nonce_lifetime = DFLT_NONCE_LIFE; + conf->dir_name = apr_pstrdup(p, dir); + conf->algorithm = DFLT_ALGORITHM; + } + + return conf; +} + +static const char *set_realm(cmd_parms *cmd, void *config, const char *realm) +{ + digest_config_rec *conf = (digest_config_rec *) config; +#ifdef AP_DEBUG + int i; + + /* check that we got random numbers */ + for (i = 0; i < SECRET_LEN; i++) { + if (secret[i] != 0) + break; + } + ap_assert(i < SECRET_LEN); +#endif + + /* The core already handles the realm, but it's just too convenient to + * grab it ourselves too and cache some setups. However, we need to + * let the core get at it too, which is why we decline at the end - + * this relies on the fact that http_core is last in the list. + */ + conf->realm = realm; + + /* we precompute the part of the nonce hash that is constant (well, + * the host:port would be too, but that varies for .htaccess files + * and directives outside a virtual host section) + */ + apr_sha1_init(&conf->nonce_ctx); + apr_sha1_update_binary(&conf->nonce_ctx, secret, SECRET_LEN); + apr_sha1_update_binary(&conf->nonce_ctx, (const unsigned char *) realm, + strlen(realm)); + + return DECLINE_CMD; +} + +static const char *add_authn_provider(cmd_parms *cmd, void *config, + const char *arg) +{ + digest_config_rec *conf = (digest_config_rec*)config; + authn_provider_list *newp; + + newp = apr_pcalloc(cmd->pool, sizeof(authn_provider_list)); + newp->provider_name = arg; + + /* lookup and cache the actual provider now */ + newp->provider = ap_lookup_provider(AUTHN_PROVIDER_GROUP, + newp->provider_name, + AUTHN_PROVIDER_VERSION); + + if (newp->provider == NULL) { + /* by the time they use it, the provider should be loaded and + registered with us. */ + return apr_psprintf(cmd->pool, + "Unknown Authn provider: %s", + newp->provider_name); + } + + if (!newp->provider->get_realm_hash) { + /* if it doesn't provide the appropriate function, reject it */ + return apr_psprintf(cmd->pool, + "The '%s' Authn provider doesn't support " + "Digest Authentication", newp->provider_name); + } + + /* Add it to the list now. */ + if (!conf->providers) { + conf->providers = newp; + } + else { + authn_provider_list *last = conf->providers; + + while (last->next) { + last = last->next; + } + last->next = newp; + } + + return NULL; +} + +static const char *set_qop(cmd_parms *cmd, void *config, const char *op) +{ + digest_config_rec *conf = (digest_config_rec *) config; + + if (!ap_cstr_casecmp(op, "none")) { + apr_array_clear(conf->qop_list); + *(const char **)apr_array_push(conf->qop_list) = "none"; + return NULL; + } + + if (!ap_cstr_casecmp(op, "auth-int")) { + return "AuthDigestQop auth-int is not implemented"; + } + else if (ap_cstr_casecmp(op, "auth")) { + return apr_pstrcat(cmd->pool, "Unrecognized qop: ", op, NULL); + } + + *(const char **)apr_array_push(conf->qop_list) = op; + + return NULL; +} + +static const char *set_nonce_lifetime(cmd_parms *cmd, void *config, + const char *t) +{ + char *endptr; + long lifetime; + + lifetime = strtol(t, &endptr, 10); + if (endptr < (t+strlen(t)) && !apr_isspace(*endptr)) { + return apr_pstrcat(cmd->pool, + "Invalid time in AuthDigestNonceLifetime: ", + t, NULL); + } + + ((digest_config_rec *) config)->nonce_lifetime = apr_time_from_sec(lifetime); + return NULL; +} + +static const char *set_nonce_format(cmd_parms *cmd, void *config, + const char *fmt) +{ + return "AuthDigestNonceFormat is not implemented"; +} + +static const char *set_nc_check(cmd_parms *cmd, void *config, int flag) +{ +#if !APR_HAS_SHARED_MEMORY + if (flag) { + return "AuthDigestNcCheck: ERROR: nonce-count checking " + "is not supported on platforms without shared-memory " + "support"; + } +#endif + + ((digest_config_rec *) config)->check_nc = flag; + return NULL; +} + +static const char *set_algorithm(cmd_parms *cmd, void *config, const char *alg) +{ + if (!ap_cstr_casecmp(alg, "MD5-sess")) { + return "AuthDigestAlgorithm: ERROR: algorithm `MD5-sess' " + "is not implemented"; + } + else if (ap_cstr_casecmp(alg, "MD5")) { + return apr_pstrcat(cmd->pool, "Invalid algorithm in AuthDigestAlgorithm: ", alg, NULL); + } + + ((digest_config_rec *) config)->algorithm = alg; + return NULL; +} + +static const char *set_uri_list(cmd_parms *cmd, void *config, const char *uri) +{ + digest_config_rec *c = (digest_config_rec *) config; + if (c->uri_list) { + c->uri_list[strlen(c->uri_list)-1] = '\0'; + c->uri_list = apr_pstrcat(cmd->pool, c->uri_list, " ", uri, "\"", NULL); + } + else { + c->uri_list = apr_pstrcat(cmd->pool, ", domain=\"", uri, "\"", NULL); + } + return NULL; +} + +static const char *set_shmem_size(cmd_parms *cmd, void *config, + const char *size_str) +{ + char *endptr; + long size, min; + + size = strtol(size_str, &endptr, 10); + while (apr_isspace(*endptr)) endptr++; + if (*endptr == '\0' || *endptr == 'b' || *endptr == 'B') { + ; + } + else if (*endptr == 'k' || *endptr == 'K') { + size *= 1024; + } + else if (*endptr == 'm' || *endptr == 'M') { + size *= 1048576; + } + else { + return apr_pstrcat(cmd->pool, "Invalid size in AuthDigestShmemSize: ", + size_str, NULL); + } + + min = sizeof(*client_list) + sizeof(client_entry*) + sizeof(client_entry); + if (size < min) { + return apr_psprintf(cmd->pool, "size in AuthDigestShmemSize too small: " + "%ld < %ld", size, min); + } + + shmem_size = size; + num_buckets = (size - sizeof(*client_list)) / + (sizeof(client_entry*) + HASH_DEPTH * sizeof(client_entry)); + if (num_buckets == 0) { + num_buckets = 1; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01763) + "Set shmem-size: %" APR_SIZE_T_FMT ", num-buckets: %ld", + shmem_size, num_buckets); + + return NULL; +} + +static const command_rec digest_cmds[] = +{ + AP_INIT_TAKE1("AuthName", set_realm, NULL, OR_AUTHCFG, + "The authentication realm (e.g. \"Members Only\")"), + AP_INIT_ITERATE("AuthDigestProvider", add_authn_provider, NULL, OR_AUTHCFG, + "specify the auth providers for a directory or location"), + AP_INIT_ITERATE("AuthDigestQop", set_qop, NULL, OR_AUTHCFG, + "A list of quality-of-protection options"), + AP_INIT_TAKE1("AuthDigestNonceLifetime", set_nonce_lifetime, NULL, OR_AUTHCFG, + "Maximum lifetime of the server nonce (seconds)"), + AP_INIT_TAKE1("AuthDigestNonceFormat", set_nonce_format, NULL, OR_AUTHCFG, + "The format to use when generating the server nonce"), + AP_INIT_FLAG("AuthDigestNcCheck", set_nc_check, NULL, OR_AUTHCFG, + "Whether or not to check the nonce-count sent by the client"), + AP_INIT_TAKE1("AuthDigestAlgorithm", set_algorithm, NULL, OR_AUTHCFG, + "The algorithm used for the hash calculation"), + AP_INIT_ITERATE("AuthDigestDomain", set_uri_list, NULL, OR_AUTHCFG, + "A list of URI's which belong to the same protection space as the current URI"), + AP_INIT_TAKE1("AuthDigestShmemSize", set_shmem_size, NULL, RSRC_CONF, + "The amount of shared memory to allocate for keeping track of clients"), + {NULL} +}; + + +/* + * client list code + * + * Each client is assigned a number, which is transferred in the opaque + * field of the WWW-Authenticate and Authorization headers. The number + * is just a simple counter which is incremented for each new client. + * Clients can't forge this number because it is hashed up into the + * server nonce, and that is checked. + * + * The clients are kept in a simple hash table, which consists of an + * array of client_entry's, each with a linked list of entries hanging + * off it. The client's number modulo the size of the array gives the + * bucket number. + * + * The clients are garbage collected whenever a new client is allocated + * but there is not enough space left in the shared memory segment. A + * simple semi-LRU is used for this: whenever a client entry is accessed + * it is moved to the beginning of the linked list in its bucket (this + * also makes for faster lookups for current clients). The garbage + * collecter then just removes the oldest entry (i.e. the one at the + * end of the list) in each bucket. + * + * The main advantages of the above scheme are that it's easy to implement + * and it keeps the hash table evenly balanced (i.e. same number of entries + * in each bucket). The major disadvantage is that you may be throwing + * entries out which are in active use. This is not tragic, as these + * clients will just be sent a new client id (opaque field) and nonce + * with a stale=true (i.e. it will just look like the nonce expired, + * thereby forcing an extra round trip). If the shared memory segment + * has enough headroom over the current client set size then this should + * not occur too often. + * + * To help tune the size of the shared memory segment (and see if the + * above algorithm is really sufficient) a set of counters is kept + * indicating the number of clients held, the number of garbage collected + * clients, and the number of erroneously purged clients. These are printed + * out at each garbage collection run. Note that access to the counters is + * not synchronized because they are just indicaters, and whether they are + * off by a few doesn't matter; and for the same reason no attempt is made + * to guarantee the num_renewed is correct in the face of clients spoofing + * the opaque field. + */ + +/* + * Get the client given its client number (the key). Returns the entry, + * or NULL if it's not found. + * + * Access to the list itself is synchronized via locks. However, access + * to the entry returned by get_client() is NOT synchronized. This means + * that there are potentially problems if a client uses multiple, + * simultaneous connections to access url's within the same protection + * space. However, these problems are not new: when using multiple + * connections you have no guarantee of the order the requests are + * processed anyway, so you have problems with the nonce-count and + * one-time nonces anyway. + */ +static client_entry *get_client(unsigned long key, const request_rec *r) +{ + int bucket; + client_entry *entry, *prev = NULL; + + + if (!key || !client_shm) return NULL; + + bucket = key % client_list->tbl_len; + entry = client_list->table[bucket]; + + apr_global_mutex_lock(client_lock); + + while (entry && key != entry->key) { + prev = entry; + entry = entry->next; + } + + if (entry && prev) { /* move entry to front of list */ + prev->next = entry->next; + entry->next = client_list->table[bucket]; + client_list->table[bucket] = entry; + } + + apr_global_mutex_unlock(client_lock); + + if (entry) { + ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01764) + "get_client(): client %lu found", key); + } + else { + ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01765) + "get_client(): client %lu not found", key); + } + + return entry; +} + + +/* A simple garbage-collecter to remove unused clients. It removes the + * last entry in each bucket and updates the counters. Returns the + * number of removed entries. + */ +static long gc(server_rec *s) +{ + client_entry *entry, *prev; + unsigned long num_removed = 0, idx; + + /* garbage collect all last entries */ + + for (idx = 0; idx < client_list->tbl_len; idx++) { + entry = client_list->table[idx]; + prev = NULL; + + if (!entry) { + /* This bucket is empty. */ + continue; + } + + while (entry->next) { /* find last entry */ + prev = entry; + entry = entry->next; + } + if (prev) { + prev->next = NULL; /* cut list */ + } + else { + client_list->table[idx] = NULL; + } + if (entry) { /* remove entry */ + apr_status_t err; + + err = rmm_free(client_rmm, entry); + num_removed++; + + if (err) { + /* Nothing we can really do but log... */ + ap_log_error(APLOG_MARK, APLOG_ERR, err, s, APLOGNO(10007) + "Failed to free auth_digest client allocation"); + } + } + } + + /* update counters and log */ + + client_list->num_entries -= num_removed; + client_list->num_removed += num_removed; + + return num_removed; +} + + +/* + * Add a new client to the list. Returns the entry if successful, NULL + * otherwise. This triggers the garbage collection if memory is low. + */ +static client_entry *add_client(unsigned long key, client_entry *info, + server_rec *s) +{ + int bucket; + client_entry *entry; + + + if (!key || !client_shm) { + return NULL; + } + + bucket = key % client_list->tbl_len; + + apr_global_mutex_lock(client_lock); + + /* try to allocate a new entry */ + + entry = rmm_malloc(client_rmm, sizeof(client_entry)); + if (!entry) { + long num_removed = gc(s); + ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(01766) + "gc'd %ld client entries. Total new clients: " + "%ld; Total removed clients: %ld; Total renewed clients: " + "%ld", num_removed, + client_list->num_created - client_list->num_renewed, + client_list->num_removed, client_list->num_renewed); + entry = rmm_malloc(client_rmm, sizeof(client_entry)); + if (!entry) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01767) + "unable to allocate new auth_digest client"); + apr_global_mutex_unlock(client_lock); + return NULL; /* give up */ + } + } + + /* now add the entry */ + + memcpy(entry, info, sizeof(client_entry)); + entry->key = key; + entry->next = client_list->table[bucket]; + client_list->table[bucket] = entry; + client_list->num_created++; + client_list->num_entries++; + + apr_global_mutex_unlock(client_lock); + + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01768) + "allocated new client %lu", key); + + return entry; +} + + +/* + * Authorization header parser code + */ + +/* Parse the Authorization header, if it exists */ +static int get_digest_rec(request_rec *r, digest_header_rec *resp) +{ + const char *auth_line; + apr_size_t l; + int vk = 0, vv = 0; + char *key, *value; + + auth_line = apr_table_get(r->headers_in, + (PROXYREQ_PROXY == r->proxyreq) + ? "Proxy-Authorization" + : "Authorization"); + if (!auth_line) { + resp->auth_hdr_sts = NO_HEADER; + return !OK; + } + + resp->scheme = ap_getword_white(r->pool, &auth_line); + if (ap_cstr_casecmp(resp->scheme, "Digest")) { + resp->auth_hdr_sts = NOT_DIGEST; + return !OK; + } + + l = strlen(auth_line); + + key = apr_palloc(r->pool, l+1); + value = apr_palloc(r->pool, l+1); + + while (auth_line[0] != '\0') { + + /* find key */ + + while (apr_isspace(auth_line[0])) { + auth_line++; + } + vk = 0; + while (auth_line[0] != '=' && auth_line[0] != ',' + && auth_line[0] != '\0' && !apr_isspace(auth_line[0])) { + key[vk++] = *auth_line++; + } + key[vk] = '\0'; + while (apr_isspace(auth_line[0])) { + auth_line++; + } + + /* find value */ + + vv = 0; + if (auth_line[0] == '=') { + auth_line++; + while (apr_isspace(auth_line[0])) { + auth_line++; + } + + if (auth_line[0] == '\"') { /* quoted string */ + auth_line++; + while (auth_line[0] != '\"' && auth_line[0] != '\0') { + if (auth_line[0] == '\\' && auth_line[1] != '\0') { + auth_line++; /* escaped char */ + } + value[vv++] = *auth_line++; + } + if (auth_line[0] != '\0') { + auth_line++; + } + } + else { /* token */ + while (auth_line[0] != ',' && auth_line[0] != '\0' + && !apr_isspace(auth_line[0])) { + value[vv++] = *auth_line++; + } + } + } + value[vv] = '\0'; + + while (auth_line[0] != ',' && auth_line[0] != '\0') { + auth_line++; + } + if (auth_line[0] != '\0') { + auth_line++; + } + + if (!ap_cstr_casecmp(key, "username")) + resp->username = apr_pstrdup(r->pool, value); + else if (!ap_cstr_casecmp(key, "realm")) + resp->realm = apr_pstrdup(r->pool, value); + else if (!ap_cstr_casecmp(key, "nonce")) + resp->nonce = apr_pstrdup(r->pool, value); + else if (!ap_cstr_casecmp(key, "uri")) + resp->uri = apr_pstrdup(r->pool, value); + else if (!ap_cstr_casecmp(key, "response")) + resp->digest = apr_pstrdup(r->pool, value); + else if (!ap_cstr_casecmp(key, "algorithm")) + resp->algorithm = apr_pstrdup(r->pool, value); + else if (!ap_cstr_casecmp(key, "cnonce")) + resp->cnonce = apr_pstrdup(r->pool, value); + else if (!ap_cstr_casecmp(key, "opaque")) + resp->opaque = apr_pstrdup(r->pool, value); + else if (!ap_cstr_casecmp(key, "qop")) + resp->message_qop = apr_pstrdup(r->pool, value); + else if (!ap_cstr_casecmp(key, "nc")) + resp->nonce_count = apr_pstrdup(r->pool, value); + } + + if (!resp->username || !resp->realm || !resp->nonce || !resp->uri + || !resp->digest + || (resp->message_qop && (!resp->cnonce || !resp->nonce_count))) { + resp->auth_hdr_sts = INVALID; + return !OK; + } + + if (resp->opaque) { + resp->opaque_num = (unsigned long) strtol(resp->opaque, NULL, 16); + } + + resp->auth_hdr_sts = VALID; + return OK; +} + + +/* Because the browser may preemptively send auth info, incrementing the + * nonce-count when it does, and because the client does not get notified + * if the URI didn't need authentication after all, we need to be sure to + * update the nonce-count each time we receive an Authorization header no + * matter what the final outcome of the request. Furthermore this is a + * convenient place to get the request-uri (before any subrequests etc + * are initiated) and to initialize the request_config. + * + * Note that this must be called after mod_proxy had its go so that + * r->proxyreq is set correctly. + */ +static int parse_hdr_and_update_nc(request_rec *r) +{ + digest_header_rec *resp; + int res; + + if (!ap_is_initial_req(r)) { + return DECLINED; + } + + resp = apr_pcalloc(r->pool, sizeof(digest_header_rec)); + resp->raw_request_uri = r->unparsed_uri; + resp->psd_request_uri = &r->parsed_uri; + resp->needed_auth = 0; + resp->method = r->method; + ap_set_module_config(r->request_config, &auth_digest_module, resp); + + res = get_digest_rec(r, resp); + resp->client = get_client(resp->opaque_num, r); + if (res == OK && resp->client) { + resp->client->nonce_count++; + } + + return DECLINED; +} + + +/* + * Nonce generation code + */ + +/* The hash part of the nonce is a SHA-1 hash of the time, realm, server host + * and port, opaque, and our secret. + */ +static void gen_nonce_hash(char *hash, const char *timestr, const char *opaque, + const server_rec *server, + const digest_config_rec *conf) +{ + unsigned char sha1[APR_SHA1_DIGESTSIZE]; + apr_sha1_ctx_t ctx; + + memcpy(&ctx, &conf->nonce_ctx, sizeof(ctx)); + /* + apr_sha1_update_binary(&ctx, (const unsigned char *) server->server_hostname, + strlen(server->server_hostname)); + apr_sha1_update_binary(&ctx, (const unsigned char *) &server->port, + sizeof(server->port)); + */ + apr_sha1_update_binary(&ctx, (const unsigned char *) timestr, strlen(timestr)); + if (opaque) { + apr_sha1_update_binary(&ctx, (const unsigned char *) opaque, + strlen(opaque)); + } + apr_sha1_final(sha1, &ctx); + + ap_bin2hex(sha1, APR_SHA1_DIGESTSIZE, hash); +} + + +/* The nonce has the format b64(time)+hash . + */ +static const char *gen_nonce(apr_pool_t *p, apr_time_t now, const char *opaque, + const server_rec *server, + const digest_config_rec *conf) +{ + char *nonce = apr_palloc(p, NONCE_LEN+1); + time_rec t; + + if (conf->nonce_lifetime != 0) { + t.time = now; + } + else if (otn_counter) { + /* this counter is not synch'd, because it doesn't really matter + * if it counts exactly. + */ + t.time = (*otn_counter)++; + } + else { + /* XXX: WHAT IS THIS CONSTANT? */ + t.time = 42; + } + apr_base64_encode_binary(nonce, t.arr, sizeof(t.arr)); + gen_nonce_hash(nonce+NONCE_TIME_LEN, nonce, opaque, server, conf); + + return nonce; +} + + +/* + * Opaque and hash-table management + */ + +/* + * Generate a new client entry, add it to the list, and return the + * entry. Returns NULL if failed. + */ +static client_entry *gen_client(const request_rec *r) +{ + unsigned long op; + client_entry new_entry = { 0, NULL, 0, "" }, *entry; + + if (!opaque_cntr) { + return NULL; + } + + apr_global_mutex_lock(opaque_lock); + op = (*opaque_cntr)++; + apr_global_mutex_unlock(opaque_lock); + + if (!(entry = add_client(op, &new_entry, r->server))) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01769) + "failed to allocate client entry - ignoring client"); + return NULL; + } + + return entry; +} + + +/* + * Authorization challenge generation code (for WWW-Authenticate) + */ + +static const char *ltox(apr_pool_t *p, unsigned long num) +{ + if (num != 0) { + return apr_psprintf(p, "%lx", num); + } + else { + return ""; + } +} + +static void note_digest_auth_failure(request_rec *r, + const digest_config_rec *conf, + digest_header_rec *resp, int stale) +{ + const char *qop, *opaque, *opaque_param, *domain, *nonce; + + /* Setup qop */ + if (apr_is_empty_array(conf->qop_list)) { + qop = ", qop=\"auth\""; + } + else if (!ap_cstr_casecmp(*(const char **)(conf->qop_list->elts), "none")) { + qop = ""; + } + else { + qop = apr_pstrcat(r->pool, ", qop=\"", + apr_array_pstrcat(r->pool, conf->qop_list, ','), + "\"", + NULL); + } + + /* Setup opaque */ + + if (resp->opaque == NULL) { + /* new client */ + if ((conf->check_nc || conf->nonce_lifetime == 0) + && (resp->client = gen_client(r)) != NULL) { + opaque = ltox(r->pool, resp->client->key); + } + else { + opaque = ""; /* opaque not needed */ + } + } + else if (resp->client == NULL) { + /* client info was gc'd */ + resp->client = gen_client(r); + if (resp->client != NULL) { + opaque = ltox(r->pool, resp->client->key); + stale = 1; + client_list->num_renewed++; + } + else { + opaque = ""; /* ??? */ + } + } + else { + opaque = resp->opaque; + /* we're generating a new nonce, so reset the nonce-count */ + resp->client->nonce_count = 0; + } + + if (opaque[0]) { + opaque_param = apr_pstrcat(r->pool, ", opaque=\"", opaque, "\"", NULL); + } + else { + opaque_param = NULL; + } + + /* Setup nonce */ + + nonce = gen_nonce(r->pool, r->request_time, opaque, r->server, conf); + if (resp->client && conf->nonce_lifetime == 0) { + memcpy(resp->client->last_nonce, nonce, NONCE_LEN+1); + } + + /* setup domain attribute. We want to send this attribute wherever + * possible so that the client won't send the Authorization header + * unnecessarily (it's usually > 200 bytes!). + */ + + + /* don't send domain + * - for proxy requests + * - if it's not specified + */ + if (r->proxyreq || !conf->uri_list) { + domain = NULL; + } + else { + domain = conf->uri_list; + } + + apr_table_mergen(r->err_headers_out, + (PROXYREQ_PROXY == r->proxyreq) + ? "Proxy-Authenticate" : "WWW-Authenticate", + apr_psprintf(r->pool, "Digest realm=\"%s\", " + "nonce=\"%s\", algorithm=%s%s%s%s%s", + ap_auth_name(r), nonce, conf->algorithm, + opaque_param ? opaque_param : "", + domain ? domain : "", + stale ? ", stale=true" : "", qop)); + +} + +static int hook_note_digest_auth_failure(request_rec *r, const char *auth_type) +{ + request_rec *mainreq; + digest_header_rec *resp; + digest_config_rec *conf; + + if (ap_cstr_casecmp(auth_type, "Digest")) + return DECLINED; + + /* get the client response and mark */ + + mainreq = r; + while (mainreq->main != NULL) { + mainreq = mainreq->main; + } + while (mainreq->prev != NULL) { + mainreq = mainreq->prev; + } + resp = (digest_header_rec *) ap_get_module_config(mainreq->request_config, + &auth_digest_module); + resp->needed_auth = 1; + + + /* get our conf */ + + conf = (digest_config_rec *) ap_get_module_config(r->per_dir_config, + &auth_digest_module); + + note_digest_auth_failure(r, conf, resp, 0); + + return OK; +} + + +/* + * Authorization header verification code + */ + +static authn_status get_hash(request_rec *r, const char *user, + digest_config_rec *conf, const char **rethash) +{ + authn_status auth_result; + char *password; + authn_provider_list *current_provider; + + current_provider = conf->providers; + do { + const authn_provider *provider; + + /* For now, if a provider isn't set, we'll be nice and use the file + * provider. + */ + if (!current_provider) { + provider = ap_lookup_provider(AUTHN_PROVIDER_GROUP, + AUTHN_DEFAULT_PROVIDER, + AUTHN_PROVIDER_VERSION); + + if (!provider || !provider->get_realm_hash) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01770) + "No Authn provider configured"); + auth_result = AUTH_GENERAL_ERROR; + break; + } + apr_table_setn(r->notes, AUTHN_PROVIDER_NAME_NOTE, AUTHN_DEFAULT_PROVIDER); + } + else { + provider = current_provider->provider; + apr_table_setn(r->notes, AUTHN_PROVIDER_NAME_NOTE, current_provider->provider_name); + } + + + /* We expect the password to be md5 hash of user:realm:password */ + auth_result = provider->get_realm_hash(r, user, conf->realm, + &password); + + apr_table_unset(r->notes, AUTHN_PROVIDER_NAME_NOTE); + + /* Something occurred. Stop checking. */ + if (auth_result != AUTH_USER_NOT_FOUND) { + break; + } + + /* If we're not really configured for providers, stop now. */ + if (!conf->providers) { + break; + } + + current_provider = current_provider->next; + } while (current_provider); + + if (auth_result == AUTH_USER_FOUND) { + *rethash = password; + } + + return auth_result; +} + +static int check_nc(const request_rec *r, const digest_header_rec *resp, + const digest_config_rec *conf) +{ + unsigned long nc; + const char *snc = resp->nonce_count; + char *endptr; + + if (conf->check_nc && !client_shm) { + /* Shouldn't happen, but just in case... */ + ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01771) + "cannot check nonce count without shared memory"); + return OK; + } + + if (!conf->check_nc || !client_shm) { + return OK; + } + + if (!apr_is_empty_array(conf->qop_list) && + !ap_cstr_casecmp(*(const char **)(conf->qop_list->elts), "none")) { + /* qop is none, client must not send a nonce count */ + if (snc != NULL) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01772) + "invalid nc %s received - no nonce count allowed when qop=none", + snc); + return !OK; + } + /* qop is none, cannot check nonce count */ + return OK; + } + + nc = strtol(snc, &endptr, 16); + if (endptr < (snc+strlen(snc)) && !apr_isspace(*endptr)) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01773) + "invalid nc %s received - not a number", snc); + return !OK; + } + + if (!resp->client) { + return !OK; + } + + if (nc != resp->client->nonce_count) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01774) + "Warning, possible replay attack: nonce-count " + "check failed: %lu != %lu", nc, + resp->client->nonce_count); + return !OK; + } + + return OK; +} + +static int check_nonce(request_rec *r, digest_header_rec *resp, + const digest_config_rec *conf) +{ + apr_time_t dt; + time_rec nonce_time; + char tmp, hash[NONCE_HASH_LEN+1]; + + /* Since the time part of the nonce is a base64 encoding of an + * apr_time_t (8 bytes), it should end with a '=', fail early otherwise. + */ + if (strlen(resp->nonce) != NONCE_LEN + || resp->nonce[NONCE_TIME_LEN - 1] != '=') { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01775) + "invalid nonce '%s' received - length is not %d " + "or time encoding is incorrect", + resp->nonce, NONCE_LEN); + note_digest_auth_failure(r, conf, resp, 1); + return HTTP_UNAUTHORIZED; + } + + tmp = resp->nonce[NONCE_TIME_LEN]; + resp->nonce[NONCE_TIME_LEN] = '\0'; + apr_base64_decode_binary(nonce_time.arr, resp->nonce); + gen_nonce_hash(hash, resp->nonce, resp->opaque, r->server, conf); + resp->nonce[NONCE_TIME_LEN] = tmp; + resp->nonce_time = nonce_time.time; + + if (strcmp(hash, resp->nonce+NONCE_TIME_LEN)) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01776) + "invalid nonce %s received - hash is not %s", + resp->nonce, hash); + note_digest_auth_failure(r, conf, resp, 1); + return HTTP_UNAUTHORIZED; + } + + dt = r->request_time - nonce_time.time; + if (conf->nonce_lifetime > 0 && dt < 0) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01777) + "invalid nonce %s received - user attempted " + "time travel", resp->nonce); + note_digest_auth_failure(r, conf, resp, 1); + return HTTP_UNAUTHORIZED; + } + + if (conf->nonce_lifetime > 0) { + if (dt > conf->nonce_lifetime) { + ap_log_rerror(APLOG_MARK, APLOG_INFO, 0,r, APLOGNO(01778) + "user %s: nonce expired (%.2f seconds old " + "- max lifetime %.2f) - sending new nonce", + r->user, (double)apr_time_sec(dt), + (double)apr_time_sec(conf->nonce_lifetime)); + note_digest_auth_failure(r, conf, resp, 1); + return HTTP_UNAUTHORIZED; + } + } + else if (conf->nonce_lifetime == 0 && resp->client) { + if (memcmp(resp->client->last_nonce, resp->nonce, NONCE_LEN)) { + ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(01779) + "user %s: one-time-nonce mismatch - sending " + "new nonce", r->user); + note_digest_auth_failure(r, conf, resp, 1); + return HTTP_UNAUTHORIZED; + } + } + /* else (lifetime < 0) => never expires */ + + return OK; +} + +/* The actual MD5 code... whee */ + +/* RFC-2069 */ +static const char *old_digest(const request_rec *r, + const digest_header_rec *resp) +{ + const char *ha2; + + ha2 = ap_md5(r->pool, (unsigned char *)apr_pstrcat(r->pool, resp->method, ":", + resp->uri, NULL)); + return ap_md5(r->pool, + (unsigned char *)apr_pstrcat(r->pool, resp->ha1, ":", + resp->nonce, ":", ha2, NULL)); +} + +/* RFC-2617 */ +static const char *new_digest(const request_rec *r, + digest_header_rec *resp) +{ + const char *ha1, *ha2, *a2; + + ha1 = resp->ha1; + + a2 = apr_pstrcat(r->pool, resp->method, ":", resp->uri, NULL); + ha2 = ap_md5(r->pool, (const unsigned char *)a2); + + return ap_md5(r->pool, + (unsigned char *)apr_pstrcat(r->pool, ha1, ":", resp->nonce, + ":", resp->nonce_count, ":", + resp->cnonce, ":", + resp->message_qop, ":", ha2, + NULL)); +} + +static void copy_uri_components(apr_uri_t *dst, + apr_uri_t *src, request_rec *r) { + if (src->scheme && src->scheme[0] != '\0') { + dst->scheme = src->scheme; + } + else { + dst->scheme = (char *) "http"; + } + + if (src->hostname && src->hostname[0] != '\0') { + dst->hostname = apr_pstrdup(r->pool, src->hostname); + ap_unescape_url(dst->hostname); + } + else { + dst->hostname = (char *) ap_get_server_name(r); + } + + if (src->port_str && src->port_str[0] != '\0') { + dst->port = src->port; + } + else { + dst->port = ap_get_server_port(r); + } + + if (src->path && src->path[0] != '\0') { + dst->path = apr_pstrdup(r->pool, src->path); + ap_unescape_url(dst->path); + } + else { + dst->path = src->path; + } + + if (src->query && src->query[0] != '\0') { + dst->query = apr_pstrdup(r->pool, src->query); + ap_unescape_url(dst->query); + } + else { + dst->query = src->query; + } + + dst->hostinfo = src->hostinfo; +} + +/* These functions return 0 if client is OK, and proper error status + * if not... either HTTP_UNAUTHORIZED, if we made a check, and it failed, or + * HTTP_INTERNAL_SERVER_ERROR, if things are so totally confused that we + * couldn't figure out how to tell if the client is authorized or not. + * + * If they return DECLINED, and all other modules also decline, that's + * treated by the server core as a configuration error, logged and + * reported as such. + */ + +/* Determine user ID, and check if the attributes are correct, if it + * really is that user, if the nonce is correct, etc. + */ + +static int authenticate_digest_user(request_rec *r) +{ + digest_config_rec *conf; + digest_header_rec *resp; + request_rec *mainreq; + const char *t; + int res; + authn_status return_code; + + /* do we require Digest auth for this URI? */ + + if (!(t = ap_auth_type(r)) || ap_cstr_casecmp(t, "Digest")) { + return DECLINED; + } + + if (!ap_auth_name(r)) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01780) + "need AuthName: %s", r->uri); + return HTTP_INTERNAL_SERVER_ERROR; + } + + + /* get the client response and mark */ + + mainreq = r; + while (mainreq->main != NULL) { + mainreq = mainreq->main; + } + while (mainreq->prev != NULL) { + mainreq = mainreq->prev; + } + resp = (digest_header_rec *) ap_get_module_config(mainreq->request_config, + &auth_digest_module); + resp->needed_auth = 1; + + + /* get our conf */ + + conf = (digest_config_rec *) ap_get_module_config(r->per_dir_config, + &auth_digest_module); + + + /* check for existence and syntax of Auth header */ + + if (resp->auth_hdr_sts != VALID) { + if (resp->auth_hdr_sts == NOT_DIGEST) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01781) + "client used wrong authentication scheme `%s': %s", + resp->scheme, r->uri); + } + else if (resp->auth_hdr_sts == INVALID) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01782) + "missing user, realm, nonce, uri, digest, " + "cnonce, or nonce_count in authorization header: %s", + r->uri); + } + /* else (resp->auth_hdr_sts == NO_HEADER) */ + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + + r->user = (char *) resp->username; + r->ap_auth_type = (char *) "Digest"; + + /* check the auth attributes */ + + if (strcmp(resp->uri, resp->raw_request_uri)) { + /* Hmm, the simple match didn't work (probably a proxy modified the + * request-uri), so lets do a more sophisticated match + */ + apr_uri_t r_uri, d_uri; + + copy_uri_components(&r_uri, resp->psd_request_uri, r); + if (apr_uri_parse(r->pool, resp->uri, &d_uri) != APR_SUCCESS) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01783) + "invalid uri <%s> in Authorization header", + resp->uri); + return HTTP_BAD_REQUEST; + } + + if (d_uri.hostname) { + ap_unescape_url(d_uri.hostname); + } + if (d_uri.path) { + ap_unescape_url(d_uri.path); + } + + if (d_uri.query) { + ap_unescape_url(d_uri.query); + } + else if (r_uri.query) { + /* MSIE compatibility hack. MSIE has some RFC issues - doesn't + * include the query string in the uri Authorization component + * or when computing the response component. the second part + * works out ok, since we can hash the header and get the same + * result. however, the uri from the request line won't match + * the uri Authorization component since the header lacks the + * query string, leaving us incompatible with a (broken) MSIE. + * + * the workaround is to fake a query string match if in the proper + * environment - BrowserMatch MSIE, for example. the cool thing + * is that if MSIE ever fixes itself the simple match ought to + * work and this code won't be reached anyway, even if the + * environment is set. + */ + + if (apr_table_get(r->subprocess_env, + "AuthDigestEnableQueryStringHack")) { + + ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(01784) + "applying AuthDigestEnableQueryStringHack " + "to uri <%s>", resp->raw_request_uri); + + d_uri.query = r_uri.query; + } + } + + if (r->method_number == M_CONNECT) { + if (!r_uri.hostinfo || strcmp(resp->uri, r_uri.hostinfo)) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01785) + "uri mismatch - <%s> does not match " + "request-uri <%s>", resp->uri, r_uri.hostinfo); + return HTTP_BAD_REQUEST; + } + } + else if ( + /* check hostname matches, if present */ + (d_uri.hostname && d_uri.hostname[0] != '\0' + && strcasecmp(d_uri.hostname, r_uri.hostname)) + /* check port matches, if present */ + || (d_uri.port_str && d_uri.port != r_uri.port) + /* check that server-port is default port if no port present */ + || (d_uri.hostname && d_uri.hostname[0] != '\0' + && !d_uri.port_str && r_uri.port != ap_default_port(r)) + /* check that path matches */ + || (d_uri.path != r_uri.path + /* either exact match */ + && (!d_uri.path || !r_uri.path + || strcmp(d_uri.path, r_uri.path)) + /* or '*' matches empty path in scheme://host */ + && !(d_uri.path && !r_uri.path && resp->psd_request_uri->hostname + && d_uri.path[0] == '*' && d_uri.path[1] == '\0')) + /* check that query matches */ + || (d_uri.query != r_uri.query + && (!d_uri.query || !r_uri.query + || strcmp(d_uri.query, r_uri.query))) + ) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01786) + "uri mismatch - <%s> does not match " + "request-uri <%s>", resp->uri, resp->raw_request_uri); + return HTTP_BAD_REQUEST; + } + } + + if (resp->opaque && resp->opaque_num == 0) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01787) + "received invalid opaque - got `%s'", + resp->opaque); + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + + if (!conf->realm) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02533) + "realm mismatch - got `%s' but no realm specified", + resp->realm); + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + + if (!resp->realm || strcmp(resp->realm, conf->realm)) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01788) + "realm mismatch - got `%s' but expected `%s'", + resp->realm, conf->realm); + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + + if (resp->algorithm != NULL + && ap_cstr_casecmp(resp->algorithm, "MD5")) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01789) + "unknown algorithm `%s' received: %s", + resp->algorithm, r->uri); + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + + return_code = get_hash(r, r->user, conf, &resp->ha1); + + if (return_code == AUTH_USER_NOT_FOUND) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01790) + "user `%s' in realm `%s' not found: %s", + r->user, conf->realm, r->uri); + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + else if (return_code == AUTH_USER_FOUND) { + /* we have a password, so continue */ + } + else if (return_code == AUTH_DENIED) { + /* authentication denied in the provider before attempting a match */ + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01791) + "user `%s' in realm `%s' denied by provider: %s", + r->user, conf->realm, r->uri); + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + else { + /* AUTH_GENERAL_ERROR (or worse) + * We'll assume that the module has already said what its error + * was in the logs. + */ + return HTTP_INTERNAL_SERVER_ERROR; + } + + if (resp->message_qop == NULL) { + /* old (rfc-2069) style digest */ + if (strcmp(resp->digest, old_digest(r, resp))) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01792) + "user %s: password mismatch: %s", r->user, + r->uri); + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + } + else { + const char *exp_digest; + int match = 0, idx; + const char **tmp = (const char **)(conf->qop_list->elts); + for (idx = 0; idx < conf->qop_list->nelts; idx++) { + if (!ap_cstr_casecmp(*tmp, resp->message_qop)) { + match = 1; + break; + } + ++tmp; + } + + if (!match + && !(apr_is_empty_array(conf->qop_list) + && !ap_cstr_casecmp(resp->message_qop, "auth"))) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01793) + "invalid qop `%s' received: %s", + resp->message_qop, r->uri); + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + + exp_digest = new_digest(r, resp); + if (!exp_digest) { + /* we failed to allocate a client struct */ + return HTTP_INTERNAL_SERVER_ERROR; + } + if (strcmp(resp->digest, exp_digest)) { + ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01794) + "user %s: password mismatch: %s", r->user, + r->uri); + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + } + + if (check_nc(r, resp, conf) != OK) { + note_digest_auth_failure(r, conf, resp, 0); + return HTTP_UNAUTHORIZED; + } + + /* Note: this check is done last so that a "stale=true" can be + generated if the nonce is old */ + if ((res = check_nonce(r, resp, conf))) { + return res; + } + + return OK; +} + +/* + * Authorization-Info header code + */ + +static int add_auth_info(request_rec *r) +{ + const digest_config_rec *conf = + (digest_config_rec *) ap_get_module_config(r->per_dir_config, + &auth_digest_module); + digest_header_rec *resp = + (digest_header_rec *) ap_get_module_config(r->request_config, + &auth_digest_module); + const char *ai = NULL, *nextnonce = ""; + + if (resp == NULL || !resp->needed_auth || conf == NULL) { + return OK; + } + + /* 2069-style entity-digest is not supported (it's too hard, and + * there are no clients which support 2069 but not 2617). */ + + /* setup nextnonce + */ + if (conf->nonce_lifetime > 0) { + /* send nextnonce if current nonce will expire in less than 30 secs */ + if ((r->request_time - resp->nonce_time) > (conf->nonce_lifetime-NEXTNONCE_DELTA)) { + nextnonce = apr_pstrcat(r->pool, ", nextnonce=\"", + gen_nonce(r->pool, r->request_time, + resp->opaque, r->server, conf), + "\"", NULL); + if (resp->client) + resp->client->nonce_count = 0; + } + } + else if (conf->nonce_lifetime == 0 && resp->client) { + const char *nonce = gen_nonce(r->pool, 0, resp->opaque, r->server, + conf); + nextnonce = apr_pstrcat(r->pool, ", nextnonce=\"", nonce, "\"", NULL); + memcpy(resp->client->last_nonce, nonce, NONCE_LEN+1); + } + /* else nonce never expires, hence no nextnonce */ + + + /* do rfc-2069 digest + */ + if (!apr_is_empty_array(conf->qop_list) && + !ap_cstr_casecmp(*(const char **)(conf->qop_list->elts), "none") + && resp->message_qop == NULL) { + /* use only RFC-2069 format */ + ai = nextnonce; + } + else { + const char *resp_dig, *ha1, *a2, *ha2; + + /* calculate rspauth attribute + */ + ha1 = resp->ha1; + + a2 = apr_pstrcat(r->pool, ":", resp->uri, NULL); + ha2 = ap_md5(r->pool, (const unsigned char *)a2); + + resp_dig = ap_md5(r->pool, + (unsigned char *)apr_pstrcat(r->pool, ha1, ":", + resp->nonce, ":", + resp->nonce_count, ":", + resp->cnonce, ":", + resp->message_qop ? + resp->message_qop : "", + ":", ha2, NULL)); + + /* assemble Authentication-Info header + */ + ai = apr_pstrcat(r->pool, + "rspauth=\"", resp_dig, "\"", + nextnonce, + resp->cnonce ? ", cnonce=\"" : "", + resp->cnonce + ? ap_escape_quotes(r->pool, resp->cnonce) + : "", + resp->cnonce ? "\"" : "", + resp->nonce_count ? ", nc=" : "", + resp->nonce_count ? resp->nonce_count : "", + resp->message_qop ? ", qop=" : "", + resp->message_qop ? resp->message_qop : "", + NULL); + } + + if (ai && ai[0]) { + apr_table_mergen(r->headers_out, + (PROXYREQ_PROXY == r->proxyreq) + ? "Proxy-Authentication-Info" + : "Authentication-Info", + ai); + } + + return OK; +} + +static void register_hooks(apr_pool_t *p) +{ + static const char * const cfgPost[]={ "http_core.c", NULL }; + static const char * const parsePre[]={ "mod_proxy.c", NULL }; + + ap_hook_pre_config(pre_init, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_post_config(initialize_module, NULL, cfgPost, APR_HOOK_MIDDLE); + ap_hook_child_init(initialize_child, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_post_read_request(parse_hdr_and_update_nc, parsePre, NULL, APR_HOOK_MIDDLE); + ap_hook_check_authn(authenticate_digest_user, NULL, NULL, APR_HOOK_MIDDLE, + AP_AUTH_INTERNAL_PER_CONF); + + ap_hook_fixups(add_auth_info, NULL, NULL, APR_HOOK_MIDDLE); + ap_hook_note_auth_failure(hook_note_digest_auth_failure, NULL, NULL, + APR_HOOK_MIDDLE); + +} + +AP_DECLARE_MODULE(auth_digest) = +{ + STANDARD20_MODULE_STUFF, + create_digest_dir_config, /* dir config creater */ + NULL, /* dir merger --- default is to override */ + NULL, /* server config */ + NULL, /* merge server config */ + digest_cmds, /* command table */ + register_hooks /* register hooks */ +}; + |