2 * Copyright (c) 2012, 2013, 2014 JANET(UK)
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of JANET(UK) nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
26 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
27 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
29 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
31 * OF THE POSSIBILITY OF SUCH DAMAGE.
33 * NOTE: Some code in this module was derived from code in
34 * mod_auth_gssapi.c which is copyrighted by CESNET. See that file
35 * for full copyright details.
37 * NOTE: Portions of the code in this file were derived from example
38 * code distributed under the Apache 2.0 license:
39 * http://www.apache.org/licenses/LICENSE-2.0
41 * This module implements the Apache server side of the GSSWeb
42 * authentiction type which allows Moonshot to be used for
43 * authentication in web applications. The module consists of two
44 * components: the hook function (gssweb_authenticate_user) that does
45 * most of the work, and an output filter (gssweb_authenticate_filter)
46 * that is registered by the hook function to send the output token
47 * back to the client in a json message that wraps the original
50 * This module uses a simple protocol between the client and server
51 * to exchange GSS tokens and nonce information. The protocol is
52 * described in the protocol.txt file included with module source.
56 #include "mod_auth_gssweb.h"
58 module AP_MODULE_DECLARE_DATA auth_gssweb_module;
60 #define command(name, func, var, type, usage) \
61 AP_INIT_ ## type (name, (void*) func, \
62 (void*)APR_OFFSETOF(gss_auth_config, var), \
63 OR_AUTHCFG | RSRC_CONF, usage)
65 static const command_rec gssweb_config_cmds[] = {
66 command("GSSServiceName", ap_set_string_slot, service_name,
67 TAKE1, "Service name used for Apache authentication."),
72 #define DEFAULT_ENCTYPE "application/x-www-form-urlencoded"
73 #define GSS_MAX_TOKEN_SIZE 4096 //TBD -- check this value
75 /* gssweb_read_req() -- reads the request data into a buffer
77 static int gssweb_read_req(request_rec *r, const char **rbuf, apr_off_t *size)
81 if((rc = ap_setup_client_block(r, REQUEST_CHUNKED_ERROR))) {
82 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_get_post_data: Failed to set up client block");
86 if(ap_should_client_block(r)) {
87 char argsbuffer[HUGE_STRING_LEN];
88 apr_off_t rsize, len_read, rpos = 0;
89 apr_off_t length = r->remaining;
91 *rbuf = (const char *) apr_pcalloc(r->pool, (apr_size_t) (length + 1));
93 while((len_read = ap_get_client_block(r, argsbuffer, sizeof(argsbuffer))) > 0) {
94 if((rpos + len_read) > length) {
95 rsize = length - rpos;
101 memcpy((char *) *rbuf + rpos, argsbuffer, (size_t) rsize);
108 /* gssweb_get_post_data() -- Gets the token and nonce from the request
111 static int gssweb_get_post_data(request_rec *r, int *nonce, gss_buffer_desc *input_token)
115 const char *key, *val, *type;
120 input_token->length = 0;
121 input_token->value = NULL;
123 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: Entering function");
125 if(r->method_number != M_POST) {
126 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_get_post_data: Request data is not a POST, declining.");
130 type = apr_table_get(r->headers_in, "Content-Type");
131 if(strcasecmp(type, DEFAULT_ENCTYPE) != 0) {
132 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_get_post_data: Unexpected content type, declining.");
136 if((rc = gssweb_read_req(r, &data, &datalen)) != OK) {
137 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_get_post_data: Data read error, rc = %d", rc);
141 while(*data && (val = ap_getword(r->pool, &data, '&'))) {
142 key = ap_getword(r->pool, &val, '=');
143 ap_unescape_url((char*)key);
144 ap_unescape_url((char*)val);
145 if (0 == strcasecmp(key, "token")) {
146 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: Found encoded token: %s", val);
147 len = apr_base64_decode_len(val);
148 if (NULL == (input_token->value = apr_pcalloc(r->pool, len+1))) {
150 input_token->length = apr_base64_decode(input_token->value, val);
152 else if (0 == strcasecmp(key, "nonce")) {
153 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: Found nonce: %s", val);
157 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_get_post_data: unknown key (%s), ignored", key);
160 if ((0 == *nonce) || (0 == input_token->length)) {
161 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_get_post_data: nonce (%d) or token len (%d) is 0, declining", *nonce, input_token->length);
165 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: returning nonce (%d) and token (%d bytes)", *nonce, input_token->length);
170 /* gssweb_authenticate_filter() -- Output filter for gssweb authentication.
171 * Wraps original response in JSON -- adding JSON to the beginning of the
172 * response, escapes double quotes in the original response, and adds JSON
173 * to the end of the response. Handles responses that involve more than
174 * one filter call by maintaining state until an EOS bucket is received.
176 static apr_status_t gssweb_authenticate_filter (ap_filter_t *f,
177 apr_bucket_brigade *brig_in)
179 request_rec *r = f->r;
180 conn_rec *c = r->connection;
181 apr_bucket_brigade *brig_out;
182 apr_bucket *bkt_in = NULL;
183 apr_bucket *bkt_out = NULL;
184 apr_bucket *bkt_eos = NULL;
185 const char *data = NULL;
187 apr_size_t enc_len = 0;
191 gss_conn_ctx conn_ctx = NULL;
192 const char *c_type = NULL;
193 const char *c_len = NULL;
194 apr_status_t ret = 0;
196 gss_log(APLOG_MARK, APLOG_DEBUG, 0, f->r, "Entering GSSWeb filter");
198 /* Get the context from the request. If the context is NULL or
199 * there is no outstanding request (no nonce set), just forward
200 * all of the buckets as-is, because the client isn't gssweb
202 if ((NULL == (conn_ctx = gss_retrieve_conn_ctx(r))) ||
203 (0 == conn_ctx->nonce)) {
204 for (bkt_in = APR_BRIGADE_FIRST(brig_in);
205 bkt_in != APR_BRIGADE_SENTINEL(brig_in);
206 bkt_in = APR_BUCKET_NEXT(bkt_in))
208 if (NULL == (brig_out = apr_brigade_create(r->pool, c->bucket_alloc))) {
209 apr_brigade_cleanup(brig_in);
210 return HTTP_INTERNAL_SERVER_ERROR;
212 apr_bucket_copy(bkt_in, &bkt_out);
213 APR_BRIGADE_INSERT_TAIL(brig_out, bkt_out);
214 ap_pass_brigade(f->next, brig_out);
216 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Failed to find valid context");
217 apr_brigade_cleanup(brig_in);
221 /* If this is the first call for a response, send opening JSON block */
222 if (GSS_FILT_NEW == conn_ctx->filter_stat) {
223 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: First filter call for response");
224 if (NULL == (brig_out = apr_brigade_create(r->pool, c->bucket_alloc))) {
225 conn_ctx->filter_stat = GSS_FILT_ERROR;
226 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate output brigade (opening)");
227 apr_brigade_cleanup(brig_in);
228 return HTTP_INTERNAL_SERVER_ERROR;
231 /* Encode the output token */
232 len = apr_base64_encode_len(conn_ctx->output_token.length);
233 if (NULL == (stoken = apr_bucket_alloc(len+1, c->bucket_alloc))) {
234 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate space for encoded output token");
235 apr_brigade_cleanup(brig_in);
236 apr_brigade_cleanup(brig_out);
237 return HTTP_INTERNAL_SERVER_ERROR;
239 apr_base64_encode_binary(stoken, conn_ctx->output_token.value, conn_ctx->output_token.length);
241 if (NULL == (data = apr_bucket_alloc(len+1024, c->bucket_alloc))) {
242 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate space for opening JSON block");
243 apr_brigade_cleanup(brig_in);
244 apr_brigade_cleanup(brig_out);
245 return HTTP_INTERNAL_SERVER_ERROR;
248 /* Send opening JSON block */
249 snprintf((char *)data, len+1024,
250 "{\"gssweb\": {\n\"token\": \"%s\",\n\"nonce\": \"%d\"},\n\"application\": {\n\"data\": \"",
251 stoken, conn_ctx->nonce);
252 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Sending (%d bytes): %s", strlen(data), data);
254 bkt_out = apr_bucket_heap_create(data, strlen(data), apr_bucket_free,
256 APR_BRIGADE_INSERT_TAIL(brig_out, bkt_out);
257 if (0 != (ret = ap_pass_brigade(f->next, brig_out))) {
258 apr_brigade_cleanup(brig_in);
259 apr_brigade_cleanup(brig_out);
263 conn_ctx->filter_stat = GSS_FILT_INPROGRESS;
266 /* Loop through the app data buckets, escaping and sending each one */
267 for (bkt_in = APR_BRIGADE_FIRST(brig_in);
268 bkt_in != APR_BRIGADE_SENTINEL(brig_in);
269 bkt_in = APR_BUCKET_NEXT(bkt_in))
271 if (NULL == (brig_out = apr_brigade_create(r->pool, c->bucket_alloc))) {
272 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate brigade (loop)");
273 conn_ctx->filter_stat = GSS_FILT_ERROR;
274 apr_brigade_cleanup(brig_in);
275 return HTTP_INTERNAL_SERVER_ERROR;
278 /* if this is an EOS, send the JSON closing block */
279 if(APR_BUCKET_IS_EOS(bkt_in))
281 /* create and add the JSON closing block */
283 if (NULL == (data = apr_bucket_alloc(1024, c->bucket_alloc))) {
284 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate space for closing JSON block");
285 apr_brigade_cleanup(brig_in);
286 apr_brigade_cleanup(brig_out);
287 return HTTP_INTERNAL_SERVER_ERROR;
290 c_type = apr_table_get(r->headers_in, "Content-Type");
291 c_len = apr_table_get(r->headers_in, "Content-Length");
292 snprintf((char *)data, 1024, "\",\n\"content-type\": \"%s\",\n\"content-length\": \"%s\"\n}\n}", c_type, c_len);
293 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Sending (%d bytes) %s", strlen(data), data);
295 bkt_out = apr_bucket_heap_create(data, strlen(data), apr_bucket_free,
297 APR_BRIGADE_INSERT_TAIL(brig_out, bkt_out);
299 /* Indicate that the next filter call is a new response */
300 conn_ctx->filter_stat = GSS_FILT_NEW;
302 /* set EOS in the outbound brigade */
303 bkt_eos = apr_bucket_eos_create(c->bucket_alloc);
304 APR_BRIGADE_INSERT_TAIL (brig_out, bkt_eos);
306 /* pass the brigade */
307 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Sending: EOS");
308 if (0 != (ret = ap_pass_brigade(f->next, brig_out))) {
309 conn_ctx->filter_stat = GSS_FILT_ERROR;
310 apr_brigade_cleanup(brig_in);
311 apr_brigade_cleanup(brig_out);
317 /* Read application data from each input bucket */
318 apr_bucket_read(bkt_in, &data, &len, APR_BLOCK_READ);
320 /* Base64 encode the data (if any) */
322 enc_len = apr_base64_encode_len(len);
323 if (NULL == (buf = apr_bucket_alloc(enc_len, c->bucket_alloc))) {
324 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate space for encoded application data");
325 apr_brigade_cleanup(brig_in);
326 apr_brigade_cleanup(brig_out);
327 return HTTP_INTERNAL_SERVER_ERROR;
329 enc_len = apr_base64_encode_binary(buf, data, len);
331 /* Put the data in a bucket and add it to the the output brigade */
332 bkt_out = apr_bucket_heap_create(buf, enc_len-1, apr_bucket_free, c->bucket_alloc);
334 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Sending (%d bytes)", enc_len);
335 APR_BRIGADE_INSERT_TAIL(brig_out, bkt_out);
337 /* Send the output brigade */
338 if (OK != (ret = ap_pass_brigade(f->next, brig_out))) {
339 apr_brigade_cleanup(brig_in);
340 apr_brigade_cleanup(brig_out);
346 /* Make sure we don't see the same data again */
347 apr_brigade_cleanup(brig_in);
351 /* gssweb_add_filter() -- Hook to add our output filter to the request
352 * (r). Called for all error responses through the
353 * gssweb_insert_error_filter hook.
356 gssweb_add_filter(request_rec *r)
358 gss_conn_ctx conn_ctx = NULL;
360 /* Get the context for this request, if any */
361 conn_ctx = gss_retrieve_conn_ctx(r);
363 /* Add the output filter */
364 ap_add_output_filter("gssweb_auth_filter", (void *)conn_ctx, r, r->connection);
368 /* gssweb_authenticate_user() -- Hook to perform actual user
369 * authentication. Will be called once for each round trip in the GSS
370 * authentication loop. Reads the tokend from the request, calls
371 * gss_accept_sec_context(), and stores the output token and context
372 * in the user data areas. Adds output filter to send the GSS
373 * output token back to the client.
376 gssweb_authenticate_user(request_rec *r)
378 const char *auth_line = NULL;
379 char *auth_type = NULL;
380 char *negotiate_ret_value = NULL;
381 gss_conn_ctx conn_ctx = NULL;
383 OM_uint32 major_status, minor_status, minor_status2;
384 gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
385 gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
386 gss_name_t client_name = GSS_C_NO_NAME;
387 gss_cred_id_t delegated_cred = GSS_C_NO_CREDENTIAL;
388 OM_uint32 ret_flags = 0;
390 int release_output_token = 1;
391 gss_auth_config *conf = NULL;
393 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "Entering GSSWeb authentication");
395 /* Get the module configuration */
396 conf = (gss_auth_config *) ap_get_module_config(r->per_dir_config,
397 &auth_gssweb_module);
399 /* Check if this is for our auth type */
400 auth_type = (char *)ap_auth_type(r);
401 if (auth_type == NULL || strcasecmp(auth_type, "GSSWeb") != 0) {
402 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r,
403 "gssweb_authenticate_user: AuthType '%s' is not GSSWeb, bailing out",
404 (auth_type) ? auth_type : "(NULL)");
409 /* Retrieve the existing context (if any), or create one */
410 if ((NULL == (conn_ctx = gss_retrieve_conn_ctx(r))) &&
411 (NULL == (conn_ctx = gss_create_conn_ctx(r, conf)))) {
412 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_user: Unable to find or create context");
415 /* Read the token and nonce from the POST */
416 if (0 != gssweb_get_post_data(r, &nonce, &input_token)) {
417 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_user: Unable to read nonce or input token from GSSWeb input");
418 gss_delete_sec_context(&minor_status, &conn_ctx->context, GSS_C_NO_BUFFER);
419 conn_ctx->context = GSS_C_NO_CONTEXT;
420 conn_ctx->state = GSS_CTX_FAILED;
421 if (0 != conn_ctx->output_token.length)
422 gss_release_buffer(&minor_status, &(conn_ctx->output_token));
423 conn_ctx->output_token.length = 0;
424 ret = HTTP_UNAUTHORIZED;
427 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: GSSWeb nonce value = %u.", nonce);
429 /* If the nonce does not match, release old context and create new */
430 if ((0 != conn_ctx->nonce) && (conn_ctx->nonce != nonce)) {
431 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r,
432 "gssweb_authenticate_user: Nonce in context (%d) does not match nonce in input (%d), new request", conn_ctx->nonce, nonce);
433 gss_cleanup_conn_ctx(conn_ctx);
434 if (NULL == (conn_ctx = gss_create_conn_ctx (r, conf))) {
435 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_user: Failed to create GSS context");
436 ret = HTTP_INTERNAL_SERVER_ERROR;
441 /* If the output filter reported an internal server error, return it */
442 if (GSS_FILT_ERROR == conn_ctx->filter_stat) {
443 gss_log(APLOG_MARK, APLOG_ERR, 0, r,
444 "gssweb_authenticate_user: Output filter returned error, reporting.");
445 ret = HTTP_INTERNAL_SERVER_ERROR;
449 /* Add the output filter to this request (for non-error returns) */
450 ap_add_output_filter("gssweb_auth_filter", (void *)conn_ctx, r, r->connection);
452 /* Call gss_accept_sec_context */
453 major_status = gss_accept_sec_context(&minor_status,
455 conn_ctx->server_creds,
457 GSS_C_NO_CHANNEL_BINDINGS,
464 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r,
465 "gssweb_authenticate_user: Client %s us their credential",
466 (ret_flags & GSS_C_DELEG_FLAG) ? "delegated" : "didn't delegate");
468 if (GSS_ERROR(major_status)) {
469 gss_log(APLOG_MARK, APLOG_ERR, 0, r,
470 "%s", get_gss_error(r, major_status, minor_status,
471 "gssweb_authenticate_user: Failed to establish authentication"));
472 conn_ctx->state = GSS_CTX_FAILED;
475 /* If there was no token returned, clear token from context and exit */
476 if (0 == output_token.length) {
477 gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_user: No output token");
478 gss_delete_sec_context(&minor_status, &conn_ctx->context, GSS_C_NO_BUFFER);
479 conn_ctx->context = GSS_C_NO_CONTEXT;
480 conn_ctx->state = GSS_CTX_FAILED;
481 if (0 != conn_ctx->output_token.length)
482 gss_release_buffer(&minor_status, &(conn_ctx->output_token));
483 conn_ctx->output_token.length = 0;
484 ret = HTTP_UNAUTHORIZED;
488 /* Store the nonce & ouput token in the stored context */
489 conn_ctx->nonce = nonce;
490 conn_ctx->output_token = output_token;
491 release_output_token = 0;
493 /* If we aren't done yet, go around again */
494 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: Accept sec context complete, continue needed");
495 if (major_status & GSS_S_CONTINUE_NEEDED) {
496 conn_ctx->state = GSS_CTX_IN_PROGRESS;
497 ret = HTTP_UNAUTHORIZED;
501 gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: Authentication succeeded!!");
502 conn_ctx->state = GSS_CTX_ESTABLISHED;
503 r->user = apr_pstrdup(r->pool, conn_ctx->user);
504 r->ap_auth_type = "GSSWeb";
509 gss_release_cred(&minor_status, &delegated_cred);
511 if ((release_output_token) && (output_token.length))
512 gss_release_buffer(&minor_status, &output_token);
514 if (client_name != GSS_C_NO_NAME)
515 gss_release_name(&minor_status, &client_name);
521 gssweb_register_hooks(apr_pool_t *p)
523 /* register the gssweb output filter */
524 ap_register_output_filter("gssweb_auth_filter", gssweb_authenticate_filter, NULL, AP_FTYPE_RESOURCE);
527 ap_hook_check_user_id(gssweb_authenticate_user, NULL, NULL, APR_HOOK_MIDDLE);
528 ap_hook_insert_error_filter(gssweb_add_filter, NULL, NULL, APR_HOOK_MIDDLE);
531 module AP_MODULE_DECLARE_DATA auth_gssweb_module = {
532 STANDARD20_MODULE_STUFF,
533 gss_config_dir_create,
538 gssweb_register_hooks