Asterisk - The Open Source Telephony Project GIT-master-d856a3e
res_srtp.c
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1/*
2 * Asterisk -- An open source telephony toolkit.
3 *
4 * Copyright (C) 2005, Mikael Magnusson
5 *
6 * Mikael Magnusson <mikma@users.sourceforge.net>
7 *
8 * See http://www.asterisk.org for more information about
9 * the Asterisk project. Please do not directly contact
10 * any of the maintainers of this project for assistance;
11 * the project provides a web site, mailing lists and IRC
12 * channels for your use.
13 *
14 * This program is free software, distributed under the terms of
15 * the GNU General Public License Version 2. See the LICENSE file
16 * at the top of the source tree.
17 *
18 * Builds on libSRTP http://srtp.sourceforge.net
19 */
20
21/*!
22 * \file
23 *
24 * \brief Secure RTP (SRTP)
25 *
26 * Secure RTP (SRTP)
27 * Specified in RFC 3711.
28 *
29 * \author Mikael Magnusson <mikma@users.sourceforge.net>
30 */
31
32/*** MODULEINFO
33 <depend>srtp</depend>
34 <use type="external">openssl</use>
35 <support_level>core</support_level>
36***/
37
38/* See https://docs.asterisk.org/Deployment/Secure-Calling/ */
39
40#include "asterisk.h" /* for NULL, size_t, memcpy, etc */
41
42#include <math.h> /* for pow */
43
44#if HAVE_SRTP_VERSION > 1
45# include <srtp2/srtp.h>
46# include "srtp/srtp_compat.h"
47# include <openssl/rand.h>
48#else
49# include <srtp/srtp.h>
50# ifdef HAVE_OPENSSL
51# include <openssl/rand.h>
52# else
53# include <srtp/crypto_kernel.h>
54# endif
55#endif
56
57#include "asterisk/astobj2.h" /* for ao2_t_ref, etc */
58#include "asterisk/frame.h" /* for AST_FRIENDLY_OFFSET */
59#include "asterisk/logger.h" /* for ast_log, ast_debug, etc */
60#include "asterisk/module.h" /* for ast_module_info, etc */
61#include "asterisk/sdp_srtp.h"
62#include "asterisk/res_srtp.h" /* for ast_srtp_cb, ast_srtp_suite, etc */
63#include "asterisk/rtp_engine.h" /* for ast_rtp_engine_register_srtp, etc */
64#include "asterisk/utils.h" /* for ast_free, ast_calloc */
65
66struct ast_srtp {
69 srtp_t session;
70 const struct ast_srtp_cb *cb;
71 void *data;
72 int warned;
73 unsigned char buf[8192 + AST_FRIENDLY_OFFSET];
74 unsigned char rtcpbuf[8192 + AST_FRIENDLY_OFFSET];
75};
76
78 srtp_policy_t sp;
79};
80
81/*! Tracks whether or not we've initialized the libsrtp library */
82static int g_initialized = 0;
83
84/* SRTP functions */
85static int ast_srtp_create(struct ast_srtp **srtp, struct ast_rtp_instance *rtp, struct ast_srtp_policy *policy);
86static int ast_srtp_replace(struct ast_srtp **srtp, struct ast_rtp_instance *rtp, struct ast_srtp_policy *policy);
87static void ast_srtp_destroy(struct ast_srtp *srtp);
88static int ast_srtp_add_stream(struct ast_srtp *srtp, struct ast_srtp_policy *policy);
89static int ast_srtp_change_source(struct ast_srtp *srtp, unsigned int from_ssrc, unsigned int to_ssrc);
90
91static int ast_srtp_unprotect(struct ast_srtp *srtp, void *buf, int *len, int rtcp);
92static int ast_srtp_protect(struct ast_srtp *srtp, void **buf, int *len, int rtcp);
93static void ast_srtp_set_cb(struct ast_srtp *srtp, const struct ast_srtp_cb *cb, void *data);
94static int ast_srtp_get_random(unsigned char *key, size_t len);
95
96/* Policy functions */
97static struct ast_srtp_policy *ast_srtp_policy_alloc(void);
98static void ast_srtp_policy_destroy(struct ast_srtp_policy *policy);
99static int ast_srtp_policy_set_suite(struct ast_srtp_policy *policy, enum ast_srtp_suite suite);
100static int ast_srtp_policy_set_master_key(struct ast_srtp_policy *policy, const unsigned char *key, size_t key_len, const unsigned char *salt, size_t salt_len);
101static void ast_srtp_policy_set_ssrc(struct ast_srtp_policy *policy, unsigned long ssrc, int inbound);
102
103static struct ast_srtp_res srtp_res = {
105 .replace = ast_srtp_replace,
106 .destroy = ast_srtp_destroy,
107 .add_stream = ast_srtp_add_stream,
108 .change_source = ast_srtp_change_source,
109 .set_cb = ast_srtp_set_cb,
110 .unprotect = ast_srtp_unprotect,
111 .protect = ast_srtp_protect,
112 .get_random = ast_srtp_get_random
113};
114
117 .destroy = ast_srtp_policy_destroy,
118 .set_suite = ast_srtp_policy_set_suite,
119 .set_master_key = ast_srtp_policy_set_master_key,
120 .set_ssrc = ast_srtp_policy_set_ssrc
121};
122
123static const char *srtp_errstr(int err)
124{
125 switch(err) {
126 case err_status_ok:
127 return "nothing to report";
128 case err_status_fail:
129 return "unspecified failure";
131 return "unsupported parameter";
133 return "couldn't allocate memory";
135 return "couldn't deallocate properly";
137 return "couldn't initialize";
139 return "can't process as much data as requested";
141 return "authentication failure";
143 return "cipher failure";
145 return "replay check failed (bad index)";
147 return "replay check failed (index too old)";
149 return "algorithm failed test routine";
151 return "unsupported operation";
153 return "no appropriate context found";
155 return "unable to perform desired validation";
157 return "can't use key any more";
158 default:
159 return "unknown";
160 }
161}
162
163static int policy_hash_fn(const void *obj, const int flags)
164{
165 const struct ast_srtp_policy *policy = obj;
166
167 return policy->sp.ssrc.type == ssrc_specific ? policy->sp.ssrc.value : policy->sp.ssrc.type;
168}
169
170static int policy_cmp_fn(void *obj, void *arg, int flags)
171{
172 const struct ast_srtp_policy *one = obj, *two = arg;
173
174 return one->sp.ssrc.type == two->sp.ssrc.type && one->sp.ssrc.value == two->sp.ssrc.value;
175}
176
177static struct ast_srtp_policy *find_policy(struct ast_srtp *srtp, const srtp_policy_t *policy, int flags)
178{
179 struct ast_srtp_policy tmp = {
180 .sp = {
181 .ssrc.type = policy->ssrc.type,
182 .ssrc.value = policy->ssrc.value,
183 },
184 };
185
186 return ao2_t_find(srtp->policies, &tmp, flags, "Looking for policy");
187}
188
189static struct ast_srtp *res_srtp_new(void)
190{
191 struct ast_srtp *srtp;
192
193 if (!(srtp = ast_calloc(1, sizeof(*srtp)))) {
194 ast_log(LOG_ERROR, "Unable to allocate memory for srtp\n");
195 return NULL;
196 }
197
199 policy_hash_fn, NULL, policy_cmp_fn, "SRTP policy container");
200 if (!srtp->policies) {
201 ast_free(srtp);
202 return NULL;
203 }
204
205 srtp->warned = 1;
206
207 return srtp;
208}
209
210/*
211 struct ast_srtp_policy
212*/
213static void srtp_event_cb(srtp_event_data_t *data)
214{
215 switch (data->event) {
216 case event_ssrc_collision:
217 ast_debug(1, "SSRC collision\n");
218 break;
219 case event_key_soft_limit:
220 ast_debug(1, "event_key_soft_limit\n");
221 break;
222 case event_key_hard_limit:
223 ast_debug(1, "event_key_hard_limit\n");
224 break;
225 case event_packet_index_limit:
226 ast_debug(1, "event_packet_index_limit\n");
227 break;
228 }
229}
230
231static void ast_srtp_policy_set_ssrc(struct ast_srtp_policy *policy,
232 unsigned long ssrc, int inbound)
233{
234 if (ssrc) {
235 policy->sp.ssrc.type = ssrc_specific;
236 policy->sp.ssrc.value = ssrc;
237 } else {
238 policy->sp.ssrc.type = inbound ? ssrc_any_inbound : ssrc_any_outbound;
239 }
240}
241
242static void policy_destructor(void *obj)
243{
244 struct ast_srtp_policy *policy = obj;
245
246 if (policy->sp.key) {
247 ast_free(policy->sp.key);
248 policy->sp.key = NULL;
249 }
250}
251
253{
254 struct ast_srtp_policy *tmp;
255
256 if (!(tmp = ao2_t_alloc(sizeof(*tmp), policy_destructor, "Allocating policy"))) {
257 ast_log(LOG_ERROR, "Unable to allocate memory for srtp_policy\n");
258 }
259
260 return tmp;
261}
262
263static void ast_srtp_policy_destroy(struct ast_srtp_policy *policy)
264{
265 ao2_t_ref(policy, -1, "Destroying policy");
266}
267
269{
270 switch (suite) {
273 return 0;
274
277 return 0;
278
279#if defined(HAVE_SRTP_192) && defined(ENABLE_SRTP_AES_192)
282 return 0;
283
286 return 0;
287#endif
288#if defined(HAVE_SRTP_256) && defined(ENABLE_SRTP_AES_256)
291 return 0;
292
295 return 0;
296#endif
297#if defined(HAVE_SRTP_GCM) && defined(ENABLE_SRTP_AES_GCM)
298 case AST_AES_GCM_128:
300 return 0;
301
304 return 0;
305#endif
306#if defined(HAVE_SRTP_GCM) && defined(ENABLE_SRTP_AES_GCM) && defined(ENABLE_SRTP_AES_256)
307 case AST_AES_GCM_256:
309 return 0;
310
313 return 0;
314#endif
315
316 default:
317 ast_log(LOG_ERROR, "Invalid crypto suite: %u\n", suite);
318 return -1;
319 }
320}
321
322static int ast_srtp_policy_set_suite(struct ast_srtp_policy *policy, enum ast_srtp_suite suite)
323{
324 return policy_set_suite(&policy->sp.rtp, suite) | policy_set_suite(&policy->sp.rtcp, suite);
325}
326
327static int ast_srtp_policy_set_master_key(struct ast_srtp_policy *policy, const unsigned char *key, size_t key_len, const unsigned char *salt, size_t salt_len)
328{
329 size_t size = key_len + salt_len;
330 unsigned char *master_key;
331
332 if (policy->sp.key) {
333 ast_free(policy->sp.key);
334 policy->sp.key = NULL;
335 }
336
337 if (!(master_key = ast_calloc(1, size))) {
338 return -1;
339 }
340
341 memcpy(master_key, key, key_len);
342 memcpy(master_key + key_len, salt, salt_len);
343
344 policy->sp.key = master_key;
345
346 return 0;
347}
348
349static int ast_srtp_get_random(unsigned char *key, size_t len)
350{
351#ifdef HAVE_OPENSSL
352 return RAND_bytes(key, len) > 0 ? 0: -1;
353#else
354 return crypto_get_random(key, len) != err_status_ok ? -1: 0;
355#endif
356}
357
358static void ast_srtp_set_cb(struct ast_srtp *srtp, const struct ast_srtp_cb *cb, void *data)
359{
360 if (!srtp) {
361 return;
362 }
363
364 srtp->cb = cb;
365 srtp->data = data;
366}
367
368/* Vtable functions */
369static int ast_srtp_unprotect(struct ast_srtp *srtp, void *buf, int *len, int flags)
370{
371 int res = 0;
372 int i;
373 int rtcp = (flags & 0x01) >> 0;
374 int retry = (flags & 0x02) >> 1;
375 struct ast_rtp_instance_stats stats = {0,};
376
377tryagain:
378
379 if (!srtp->session) {
380 ast_log(LOG_ERROR, "SRTP unprotect %s - missing session\n", rtcp ? "rtcp" : "rtp");
381 errno = EINVAL;
382 return -1;
383 }
384
385 for (i = 0; i < 2; i++) {
386 res = rtcp ? srtp_unprotect_rtcp(srtp->session, buf, len) : srtp_unprotect(srtp->session, buf, len);
387 if (res != err_status_no_ctx) {
388 break;
389 }
390
391 if (srtp->cb && srtp->cb->no_ctx) {
393 break;
394 }
395 if (srtp->cb->no_ctx(srtp->rtp, stats.remote_ssrc, srtp->data) < 0) {
396 break;
397 }
398 } else {
399 break;
400 }
401 }
402
403 if (retry == 0 && res == err_status_replay_old) {
404 ast_log(AST_LOG_NOTICE, "SRTP unprotect failed with %s, retrying\n", srtp_errstr(res));
405
406 if (srtp->session) {
407 struct ast_srtp_policy *policy;
408 struct ao2_iterator it;
409 int policies_count;
410
411 /* dealloc first */
412 ast_debug(5, "SRTP destroy before re-create\n");
413 srtp_dealloc(srtp->session);
414
415 /* get the count */
416 policies_count = ao2_container_count(srtp->policies);
417
418 /* get the first to build up */
419 it = ao2_iterator_init(srtp->policies, 0);
420 policy = ao2_iterator_next(&it);
421
422 ast_debug(5, "SRTP try to re-create\n");
423 if (policy) {
424 int res_srtp_create = srtp_create(&srtp->session, &policy->sp);
425 if (res_srtp_create == err_status_ok) {
426 ast_debug(5, "SRTP re-created with first policy\n");
427 ao2_t_ref(policy, -1, "Unreffing first policy for re-creating srtp session");
428
429 /* if we have more than one policy, add them */
430 if (policies_count > 1) {
431 ast_debug(5, "Add all the other %d policies\n",
432 policies_count - 1);
433 while ((policy = ao2_iterator_next(&it))) {
434 srtp_add_stream(srtp->session, &policy->sp);
435 ao2_t_ref(policy, -1, "Unreffing n-th policy for re-creating srtp session");
436 }
437 }
438
439 retry++;
441 goto tryagain;
442 }
443 ast_log(LOG_ERROR, "SRTP session could not be re-created after unprotect failure: %s\n", srtp_errstr(res_srtp_create));
444
445 /* If srtp_create() fails with a previously alloced session, it will have been dealloced before returning. */
446 srtp->session = NULL;
447
448 ao2_t_ref(policy, -1, "Unreffing first policy after srtp_create failed");
449 }
451 }
452 }
453
454 if (!srtp->session) {
455 errno = EINVAL;
456 return -1;
457 }
458
459 if (res != err_status_ok && res != err_status_replay_fail ) {
460 /*
461 * Authentication failures happen when an active attacker tries to
462 * insert malicious RTP packets. Furthermore, authentication failures
463 * happen, when the other party encrypts the sRTP data in an unexpected
464 * way. This happens quite often with RTCP. Therefore, when you see
465 * authentication failures, try to identify the implementation
466 * (author and product name) used by your other party. Try to investigate
467 * whether they use a custom library or an outdated version of libSRTP.
468 */
469 if (rtcp) {
470 ast_verb(2, "SRTCP unprotect failed on SSRC %u because of %s\n",
472 } else {
473 if ((srtp->warned >= 10) && !((srtp->warned - 10) % 150)) {
474 ast_verb(2, "SRTP unprotect failed on SSRC %u because of %s %d\n",
475 ast_rtp_instance_get_ssrc(srtp->rtp), srtp_errstr(res), srtp->warned);
476 srtp->warned = 11;
477 } else {
478 srtp->warned++;
479 }
480 }
481 errno = EAGAIN;
482 return -1;
483 }
484
485 return *len;
486}
487
488static int ast_srtp_protect(struct ast_srtp *srtp, void **buf, int *len, int rtcp)
489{
490 int res;
491 unsigned char *localbuf;
492
493 if (!srtp->session) {
494 ast_log(LOG_ERROR, "SRTP protect %s - missing session\n", rtcp ? "rtcp" : "rtp");
495 errno = EINVAL;
496 return -1;
497 }
498
499 if ((*len + SRTP_MAX_TRAILER_LEN) > sizeof(srtp->buf)) {
500 return -1;
501 }
502
503 localbuf = rtcp ? srtp->rtcpbuf : srtp->buf;
504
505 memcpy(localbuf, *buf, *len);
506
507 if ((res = rtcp ? srtp_protect_rtcp(srtp->session, localbuf, len) : srtp_protect(srtp->session, localbuf, len)) != err_status_ok && res != err_status_replay_fail) {
508 ast_log(LOG_WARNING, "SRTP protect: %s\n", srtp_errstr(res));
509 return -1;
510 }
511
512 *buf = localbuf;
513 return *len;
514}
515
516static int ast_srtp_create(struct ast_srtp **srtp, struct ast_rtp_instance *rtp, struct ast_srtp_policy *policy)
517{
518 struct ast_srtp *temp;
519 int status;
520
521 if (!(temp = res_srtp_new())) {
522 return -1;
523 }
525
526 /* Any failures after this point can use ast_srtp_destroy to destroy the instance */
527 status = srtp_create(&temp->session, &policy->sp);
528 if (status != err_status_ok) {
529 /* Session either wasn't created or was created and dealloced. */
530 temp->session = NULL;
531 ast_srtp_destroy(temp);
532 ast_log(LOG_ERROR, "Failed to create srtp session on rtp instance (%p) - %s\n",
534 return -1;
535 }
536
537 temp->rtp = rtp;
538 *srtp = temp;
539
540 ao2_t_link((*srtp)->policies, policy, "Created initial policy");
541
542 return 0;
543}
544
545static int ast_srtp_replace(struct ast_srtp **srtp, struct ast_rtp_instance *rtp, struct ast_srtp_policy *policy)
546{
547 struct ast_srtp *old = *srtp;
548 int res = ast_srtp_create(srtp, rtp, policy);
549
550 if (!res && old) {
551 ast_srtp_destroy(old);
552 }
553
554 if (res) {
555 ast_log(LOG_ERROR, "Failed to replace srtp (%p) on rtp instance (%p) "
556 "- keeping old\n", *srtp, rtp);
557 }
558
559 return res;
560}
561
562static void ast_srtp_destroy(struct ast_srtp *srtp)
563{
564 if (srtp->session) {
565 srtp_dealloc(srtp->session);
566 }
567
568 ao2_t_callback(srtp->policies, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL, "Unallocate policy");
569 ao2_t_ref(srtp->policies, -1, "Destroying container");
570
571 ast_free(srtp);
573}
574
575static int ast_srtp_add_stream(struct ast_srtp *srtp, struct ast_srtp_policy *policy)
576{
577 struct ast_srtp_policy *match;
578
579 /* For existing streams, replace if its an SSRC stream, or bail if its a wildcard */
580 if ((match = find_policy(srtp, &policy->sp, OBJ_POINTER))) {
581 if (policy->sp.ssrc.type != ssrc_specific) {
582 ast_log(AST_LOG_WARNING, "Cannot replace an existing wildcard policy\n");
583 ao2_t_ref(match, -1, "Unreffing already existing policy");
584 return -1;
585 } else {
586 if (srtp_remove_stream(srtp->session, match->sp.ssrc.value) != err_status_ok) {
587 ast_log(AST_LOG_WARNING, "Failed to remove SRTP stream for SSRC %u\n", match->sp.ssrc.value);
588 }
589 ao2_t_unlink(srtp->policies, match, "Remove existing match policy");
590 ao2_t_ref(match, -1, "Unreffing already existing policy");
591 }
592 }
593
594 ast_debug(3, "Adding new policy for %s %u\n",
595 policy->sp.ssrc.type == ssrc_specific ? "SSRC" : "type",
596 policy->sp.ssrc.type == ssrc_specific ? policy->sp.ssrc.value : policy->sp.ssrc.type);
597 if (srtp_add_stream(srtp->session, &policy->sp) != err_status_ok) {
598 ast_log(AST_LOG_WARNING, "Failed to add SRTP stream for %s %u\n",
599 policy->sp.ssrc.type == ssrc_specific ? "SSRC" : "type",
600 policy->sp.ssrc.type == ssrc_specific ? policy->sp.ssrc.value : policy->sp.ssrc.type);
601 return -1;
602 }
603
604 ao2_t_link(srtp->policies, policy, "Added additional stream");
605
606 return 0;
607}
608
609static int ast_srtp_change_source(struct ast_srtp *srtp, unsigned int from_ssrc, unsigned int to_ssrc)
610{
611 struct ast_srtp_policy *match;
612 struct srtp_policy_t sp = {
613 .ssrc.type = ssrc_specific,
614 .ssrc.value = from_ssrc,
615 };
617
618 /* If we find a match, return and unlink it from the container so we
619 * can change the SSRC (which is part of the hash) and then have
620 * ast_srtp_add_stream link it back in if all is well */
621 if ((match = find_policy(srtp, &sp, OBJ_POINTER | OBJ_UNLINK))) {
622 match->sp.ssrc.value = to_ssrc;
623 if (ast_srtp_add_stream(srtp, match)) {
624 ast_log(LOG_WARNING, "Couldn't add stream\n");
625 } else if ((status = srtp_remove_stream(srtp->session, from_ssrc))) {
626 ast_debug(3, "Couldn't remove stream (%u)\n", status);
627 }
628 ao2_t_ref(match, -1, "Unreffing found policy in change_source");
629 }
630
631 return 0;
632}
633
635 char *a_crypto;
636 unsigned char local_key[SRTP_MAX_KEY_LEN];
637 int tag;
638 char local_key64[((SRTP_MAX_KEY_LEN) * 8 + 5) / 6 + 1];
639 unsigned char remote_key[SRTP_MAX_KEY_LEN];
641};
642
643static void res_sdp_crypto_dtor(struct ast_sdp_crypto *crypto)
644{
645 if (crypto) {
646 ast_free(crypto->a_crypto);
647 crypto->a_crypto = NULL;
648 ast_free(crypto);
649
651 }
652}
653
654static struct ast_sdp_crypto *crypto_init_keys(struct ast_sdp_crypto *p, const int key_len)
655{
656 unsigned char remote_key[key_len];
657
658 if (srtp_res.get_random(p->local_key, key_len) < 0) {
659 return NULL;
660 }
661
663
665
666 if (p->key_len != key_len) {
667 ast_log(LOG_ERROR, "base64 encode/decode bad len %d != %d\n", p->key_len, key_len);
668 return NULL;
669 }
670
671 if (memcmp(remote_key, p->local_key, p->key_len)) {
672 ast_log(LOG_ERROR, "base64 encode/decode bad key\n");
673 return NULL;
674 }
675
676 ast_debug(1 , "local_key64 %s len %zu\n", p->local_key64, strlen(p->local_key64));
677
678 return p;
679}
680
681static struct ast_sdp_crypto *sdp_crypto_alloc(const int key_len)
682{
683 struct ast_sdp_crypto *p, *result;
684
685 if (!(p = ast_calloc(1, sizeof(*p)))) {
686 return NULL;
687 }
688 p->tag = 1;
690
691 /* default is a key which uses AST_AES_CM_128_HMAC_SHA1_xx */
693 if (!result) {
695 }
696
697 return result;
698}
699
701{
703}
704
705static int res_sdp_crypto_build_offer(struct ast_sdp_crypto *p, int taglen)
706{
707 int res;
708
709 /* Rebuild the crypto line */
710 ast_free(p->a_crypto);
711 p->a_crypto = NULL;
712
713 if ((taglen & 0x007f) == 8) {
714 res = ast_asprintf(&p->a_crypto, "%d AEAD_AES_%d_GCM_%d inline:%s",
715 p->tag, 128 + ((taglen & 0x0300) >> 2), taglen & 0x007f, p->local_key64);
716 } else if ((taglen & 0x007f) == 16) {
717 res = ast_asprintf(&p->a_crypto, "%d AEAD_AES_%d_GCM inline:%s",
718 p->tag, 128 + ((taglen & 0x0300) >> 2), p->local_key64);
719 } else if ((taglen & 0x0300) && !(taglen & 0x0080)) {
720 res = ast_asprintf(&p->a_crypto, "%d AES_%d_CM_HMAC_SHA1_%d inline:%s",
721 p->tag, 128 + ((taglen & 0x0300) >> 2), taglen & 0x007f, p->local_key64);
722 } else {
723 res = ast_asprintf(&p->a_crypto, "%d AES_CM_%d_HMAC_SHA1_%d inline:%s",
724 p->tag, 128 + ((taglen & 0x0300) >> 2), taglen & 0x007f, p->local_key64);
725 }
726 if (res == -1 || !p->a_crypto) {
727 ast_log(LOG_ERROR, "Could not allocate memory for crypto line\n");
728 return -1;
729 }
730
731 ast_debug(1, "Crypto line: a=crypto:%s\n", p->a_crypto);
732
733 return 0;
734}
735
736static int set_crypto_policy(struct ast_srtp_policy *policy, int suite_val, const unsigned char *master_key, int key_len, unsigned long ssrc, int inbound)
737{
738 if (policy_res.set_master_key(policy, master_key, key_len, NULL, 0) < 0) {
739 return -1;
740 }
741
742 if (policy_res.set_suite(policy, suite_val)) {
743 ast_log(LOG_WARNING, "Could not set remote SRTP suite\n");
744 return -1;
745 }
746
747 policy_res.set_ssrc(policy, ssrc, inbound);
748
749 return 0;
750}
751
752static int crypto_activate(struct ast_sdp_crypto *p, int suite_val, unsigned char *remote_key, int key_len, struct ast_rtp_instance *rtp)
753{
754 struct ast_srtp_policy *local_policy = NULL;
755 struct ast_srtp_policy *remote_policy = NULL;
756 struct ast_rtp_instance_stats stats = {0,};
757 int res = -1;
758
759 if (!p) {
760 return -1;
761 }
762
763 if (!(local_policy = policy_res.alloc())) {
764 return -1;
765 }
766
767 if (!(remote_policy = policy_res.alloc())) {
768 goto err;
769 }
770
772 goto err;
773 }
774
775 if (set_crypto_policy(local_policy, suite_val, p->local_key, key_len, stats.local_ssrc, 0) < 0) {
776 goto err;
777 }
778
779 if (set_crypto_policy(remote_policy, suite_val, remote_key, key_len, 0, 1) < 0) {
780 goto err;
781 }
782
783 /* Add the SRTP policies */
784 if (ast_rtp_instance_add_srtp_policy(rtp, remote_policy, local_policy, 0)) {
785 ast_log(LOG_WARNING, "Could not set SRTP policies\n");
786 goto err;
787 }
788
789 ast_debug(1 , "SRTP policy activated\n");
790 res = 0;
791
792err:
793 if (local_policy) {
794 policy_res.destroy(local_policy);
795 }
796
797 if (remote_policy) {
798 policy_res.destroy(remote_policy);
799 }
800
801 return res;
802}
803
804static int res_sdp_crypto_parse_offer(struct ast_rtp_instance *rtp, struct ast_sdp_srtp *srtp, const char *attr)
805{
806 char *str = NULL;
807 char *tag = NULL;
808 char *suite = NULL;
809 char *key_params = NULL;
810 char *key_param = NULL;
811 char *session_params = NULL;
812 char *key_salt = NULL; /* The actual master key and key salt */
813 char *lifetime = NULL; /* Key lifetime (# of RTP packets) */
814 char *mki = NULL; /* Master Key Index */
815 int found = 0;
816 int key_len_from_sdp;
817 int key_len_expected;
818 int tag_from_sdp;
819 int suite_val = 0;
820 unsigned char remote_key[SRTP_MAX_KEY_LEN];
821 int taglen;
822 double sdes_lifetime;
823 struct ast_sdp_crypto *crypto;
824 struct ast_sdp_srtp *tmp;
825
826 str = ast_strdupa(attr);
827
828 tag = strsep(&str, " ");
829 suite = strsep(&str, " ");
830 key_params = strsep(&str, " ");
831 session_params = strsep(&str, " ");
832
833 if (!tag || !suite) {
834 ast_log(LOG_WARNING, "Unrecognized crypto attribute a=%s\n", attr);
835 return -1;
836 }
837
838 /* RFC4568 9.1 - tag is 1-9 digits */
839 if (sscanf(tag, "%30d", &tag_from_sdp) != 1 || tag_from_sdp < 0 || tag_from_sdp > 999999999) {
840 ast_log(LOG_WARNING, "Unacceptable a=crypto tag: %s\n", tag);
841 return -1;
842 }
843
844 if (!ast_strlen_zero(session_params)) {
845 ast_log(LOG_WARNING, "Unsupported crypto parameters: %s\n", session_params);
846 return -1;
847 }
848
849 /* On egress, Asterisk sent several crypto lines in the SIP/SDP offer
850 The remote party might have choosen another line than the first */
851 for (tmp = srtp; tmp && tmp->crypto && tmp->crypto->tag != tag_from_sdp;) {
853 }
854 if (tmp) { /* tag matched an already created crypto line */
855 unsigned int flags = tmp->flags;
856
857 /* Make that crypto line the head of the list, not by changing the
858 list structure but by exchanging the content of the list members */
859 crypto = tmp->crypto;
860 tmp->crypto = srtp->crypto;
861 tmp->flags = srtp->flags;
862 srtp->crypto = crypto;
863 srtp->flags = flags;
864 } else {
865 crypto = srtp->crypto;
866 crypto->tag = tag_from_sdp;
867 }
868
876
877 if (!strcmp(suite, "AES_CM_128_HMAC_SHA1_80")) {
878 suite_val = AST_AES_CM_128_HMAC_SHA1_80;
880 key_len_expected = 30;
881 } else if (!strcmp(suite, "AES_CM_128_HMAC_SHA1_32")) {
882 suite_val = AST_AES_CM_128_HMAC_SHA1_32;
884 key_len_expected = 30;
885#if defined(HAVE_SRTP_192) && defined(ENABLE_SRTP_AES_192)
886 } else if (!strcmp(suite, "AES_192_CM_HMAC_SHA1_80")) {
887 suite_val = AST_AES_CM_192_HMAC_SHA1_80;
890 key_len_expected = 38;
891 } else if (!strcmp(suite, "AES_192_CM_HMAC_SHA1_32")) {
892 suite_val = AST_AES_CM_192_HMAC_SHA1_32;
895 key_len_expected = 38;
896 /* RFC used a different name while in draft, some still use that */
897 } else if (!strcmp(suite, "AES_CM_192_HMAC_SHA1_80")) {
898 suite_val = AST_AES_CM_192_HMAC_SHA1_80;
902 key_len_expected = 38;
903 } else if (!strcmp(suite, "AES_CM_192_HMAC_SHA1_32")) {
904 suite_val = AST_AES_CM_192_HMAC_SHA1_32;
908 key_len_expected = 38;
909#endif
910#if defined(HAVE_SRTP_256) && defined(ENABLE_SRTP_AES_256)
911 } else if (!strcmp(suite, "AES_256_CM_HMAC_SHA1_80")) {
912 suite_val = AST_AES_CM_256_HMAC_SHA1_80;
915 key_len_expected = 46;
916 } else if (!strcmp(suite, "AES_256_CM_HMAC_SHA1_32")) {
917 suite_val = AST_AES_CM_256_HMAC_SHA1_32;
920 key_len_expected = 46;
921 /* RFC used a different name while in draft, some still use that */
922 } else if (!strcmp(suite, "AES_CM_256_HMAC_SHA1_80")) {
923 suite_val = AST_AES_CM_256_HMAC_SHA1_80;
927 key_len_expected = 46;
928 } else if (!strcmp(suite, "AES_CM_256_HMAC_SHA1_32")) {
929 suite_val = AST_AES_CM_256_HMAC_SHA1_32;
933 key_len_expected = 46;
934#endif
935#if defined(HAVE_SRTP_GCM) && defined(ENABLE_SRTP_AES_GCM)
936 } else if (!strcmp(suite, "AEAD_AES_128_GCM")) {
937 suite_val = AST_AES_GCM_128;
939 key_len_expected = AES_128_GCM_KEYSIZE_WSALT;
940 /* RFC contained a (too) short auth tag for RTP media, some still use that */
941 } else if (!strcmp(suite, "AEAD_AES_128_GCM_8")) {
942 suite_val = AST_AES_GCM_128_8;
944 key_len_expected = AES_128_GCM_KEYSIZE_WSALT;
945#endif
946#if defined(HAVE_SRTP_GCM) && defined(ENABLE_SRTP_AES_GCM) && defined(ENABLE_SRTP_AES_256)
947 } else if (!strcmp(suite, "AEAD_AES_256_GCM")) {
948 suite_val = AST_AES_GCM_256;
951 key_len_expected = AES_256_GCM_KEYSIZE_WSALT;
952 /* RFC contained a (too) short auth tag for RTP media, some still use that */
953 } else if (!strcmp(suite, "AEAD_AES_256_GCM_8")) {
954 suite_val = AST_AES_GCM_256_8;
957 key_len_expected = AES_256_GCM_KEYSIZE_WSALT;
958#endif
959 } else {
960 ast_verb(1, "Unsupported crypto suite: %s\n", suite);
961 return -1;
962 }
963
964 while ((key_param = strsep(&key_params, ";"))) {
965 unsigned int n_lifetime;
966 char *method = NULL;
967 char *info = NULL;
968
969 method = strsep(&key_param, ":");
970 info = strsep(&key_param, ";");
971 sdes_lifetime = 0;
972
973 if (strcmp(method, "inline")) {
974 continue;
975 }
976
977 key_salt = strsep(&info, "|");
978
979 /* The next parameter can be either lifetime or MKI */
980 lifetime = strsep(&info, "|");
981 if (!lifetime) {
982 found = 1;
983 break;
984 }
985
986 mki = strchr(lifetime, ':');
987 if (mki) {
988 mki = lifetime;
989 lifetime = NULL;
990 } else {
991 mki = strsep(&info, "|");
992 }
993
994 if (mki && *mki != '1') {
995 ast_log(LOG_NOTICE, "Crypto MKI handling is not supported: ignoring attribute %s\n", attr);
996 continue;
997 }
998
999 if (lifetime) {
1000 if (!strncmp(lifetime, "2^", 2)) {
1001 char *lifetime_val = lifetime + 2;
1002
1003 /* Exponential lifetime */
1004 if (sscanf(lifetime_val, "%30u", &n_lifetime) != 1) {
1005 ast_log(LOG_NOTICE, "Failed to parse lifetime value in crypto attribute: %s\n", attr);
1006 continue;
1007 }
1008
1009 if (n_lifetime > 48) {
1010 /* Yeah... that's a bit big. */
1011 ast_log(LOG_NOTICE, "Crypto lifetime exponent of '%u' is a bit large; using 48\n", n_lifetime);
1012 n_lifetime = 48;
1013 }
1014 sdes_lifetime = pow(2, n_lifetime);
1015 } else {
1016 /* Decimal lifetime */
1017 if (sscanf(lifetime, "%30u", &n_lifetime) != 1) {
1018 ast_log(LOG_NOTICE, "Failed to parse lifetime value in crypto attribute: %s\n", attr);
1019 continue;
1020 }
1021 sdes_lifetime = n_lifetime;
1022 }
1023
1024 /* Accept anything above ~5.8 hours. Less than ~5.8; reject. */
1025 if (sdes_lifetime < 1048576) {
1026 ast_log(LOG_NOTICE, "Rejecting crypto attribute '%s': lifetime '%f' too short\n", attr, sdes_lifetime);
1027 continue;
1028 }
1029 }
1030
1031 ast_debug(2, "Crypto attribute '%s' accepted with lifetime '%f', MKI '%s'\n",
1032 attr, sdes_lifetime, mki ? mki : "-");
1033
1034 found = 1;
1035 break;
1036 }
1037
1038 if (!found) {
1039 ast_log(LOG_NOTICE, "SRTP crypto offer not acceptable: '%s'\n", attr);
1040 return -1;
1041 }
1042
1043 key_len_from_sdp = ast_base64decode(remote_key, key_salt, sizeof(remote_key));
1044 if (key_len_from_sdp != key_len_expected) {
1045 ast_log(LOG_WARNING, "SRTP descriptions key length is '%d', not '%d'\n",
1046 key_len_from_sdp, key_len_expected);
1047 return -1;
1048 }
1049
1050 /* on default, the key is 30 (AES-128); throw that away (only) when the suite changed actually */
1051 /* ingress: optional, but saves one expensive call to get_random(.) */
1052 /* egress: required, because the local key was communicated before the remote key is processed */
1053 if (crypto->key_len != key_len_from_sdp) {
1054 if (!crypto_init_keys(crypto, key_len_from_sdp)) {
1055 return -1;
1056 }
1057 } else if (!memcmp(crypto->remote_key, remote_key, key_len_from_sdp)) {
1058 ast_debug(1, "SRTP remote key unchanged; maintaining current policy\n");
1059 return 0;
1060 }
1061
1062 if (key_len_from_sdp > sizeof(crypto->remote_key)) {
1064 "SRTP key buffer is %zu although it must be at least %d bytes\n",
1065 sizeof(crypto->remote_key), key_len_from_sdp);
1066 return -1;
1067 }
1068 memcpy(crypto->remote_key, remote_key, key_len_from_sdp);
1069
1070 if (crypto_activate(crypto, suite_val, remote_key, key_len_from_sdp, rtp) < 0) {
1071 return -1;
1072 }
1073
1075 taglen = 32;
1076 } else if (ast_test_flag(srtp, AST_SRTP_CRYPTO_TAG_16)) {
1077 taglen = 16;
1078 } else if (ast_test_flag(srtp, AST_SRTP_CRYPTO_TAG_8)) {
1079 taglen = 8;
1080 } else {
1081 taglen = 80;
1082 }
1084 taglen |= 0x0200;
1085 } else if (ast_test_flag(srtp, AST_SRTP_CRYPTO_AES_192)) {
1086 taglen |= 0x0100;
1087 }
1089 taglen |= 0x0080;
1090 }
1091
1092 /* Finally, rebuild the crypto line */
1093 if (res_sdp_crypto_build_offer(crypto, taglen)) {
1094 return -1;
1095 }
1096
1098 return 0;
1099}
1100
1101static const char *res_sdp_srtp_get_attr(struct ast_sdp_srtp *srtp, int dtls_enabled, int default_taglen_32)
1102{
1103 int taglen;
1104
1105 if (!srtp) {
1106 return NULL;
1107 }
1108
1109 /* Set encryption properties */
1110 if (!srtp->crypto) {
1111 if (AST_LIST_NEXT(srtp, sdp_srtp_list)) {
1112 srtp->crypto = res_sdp_crypto_alloc();
1113 ast_log(LOG_ERROR, "SRTP SDP list was not empty\n");
1114 } else {
1115 const int len = default_taglen_32 ? AST_SRTP_CRYPTO_TAG_32 : AST_SRTP_CRYPTO_TAG_80;
1116 const int attr[][3] = {
1117 /* This array creates the following list:
1118 * a=crypto:1 AES_CM_128_HMAC_SHA1_ ...
1119 * a=crypto:2 AEAD_AES_128_GCM ...
1120 * a=crypto:3 AES_256_CM_HMAC_SHA1_ ...
1121 * a=crypto:4 AEAD_AES_256_GCM ...
1122 * a=crypto:5 AES_192_CM_HMAC_SHA1_ ...
1123 * something like 'AEAD_AES_192_GCM' is not specified by the RFCs
1124 *
1125 * If you want to prefer another crypto suite or you want to
1126 * exclude a suite, change this array and recompile Asterisk.
1127 * This list cannot be changed from rtp.conf because you should
1128 * know what you are doing. Especially AES-192 and AES-GCM are
1129 * broken in many VoIP clients, see
1130 * https://github.com/cisco/libsrtp/pull/170
1131 * https://github.com/cisco/libsrtp/pull/184
1132 * Furthermore, AES-GCM uses a shorter crypto-suite string which
1133 * causes Nokia phones based on Symbian/S60 to reject the whole
1134 * INVITE with status 500, even if a matching suite was offered.
1135 * AES-256 might just waste your processor cycles, especially if
1136 * your TLS transport is not secured with equivalent grade, see
1137 * https://security.stackexchange.com/q/61361
1138 * Therefore, AES-128 was preferred here.
1139 *
1140 * If you want to enable one of those defines, please, go for
1141 * CFLAGS='-DENABLE_SRTP_AES_GCM' ./configure && sudo make install
1142 */
1143 { len, 0, 30 },
1144#if defined(HAVE_SRTP_GCM) && defined(ENABLE_SRTP_AES_GCM)
1146#endif
1147#if defined(HAVE_SRTP_256) && defined(ENABLE_SRTP_AES_256)
1149#endif
1150#if defined(HAVE_SRTP_GCM) && defined(ENABLE_SRTP_AES_GCM) && defined(ENABLE_SRTP_AES_256)
1152#endif
1153#if defined(HAVE_SRTP_192) && defined(ENABLE_SRTP_AES_192)
1155#endif
1156 };
1157 struct ast_sdp_srtp *tmp = srtp;
1158 int i;
1159
1160 for (i = 0; i < ARRAY_LEN(attr); i++) {
1161 if (attr[i][0]) {
1162 ast_set_flag(tmp, attr[i][0]);
1163 }
1164 if (attr[i][1]) {
1165 ast_set_flag(tmp, attr[i][1]);
1166 }
1167 tmp->crypto = sdp_crypto_alloc(attr[i][2]); /* key_len */
1168 tmp->crypto->tag = (i + 1); /* tag starts at 1 */
1169
1170 if (i < ARRAY_LEN(attr) - 1) {
1173 }
1174 }
1175 }
1176 }
1177
1178 if (dtls_enabled) {
1179 /* If DTLS-SRTP is enabled the key details will be pulled from TLS */
1180 return NULL;
1181 }
1182
1183 /* set the key length based on INVITE or settings */
1185 taglen = 80;
1186 } else if (ast_test_flag(srtp, AST_SRTP_CRYPTO_TAG_32)) {
1187 taglen = 32;
1188 } else if (ast_test_flag(srtp, AST_SRTP_CRYPTO_TAG_16)) {
1189 taglen = 16;
1190 } else if (ast_test_flag(srtp, AST_SRTP_CRYPTO_TAG_8)) {
1191 taglen = 8;
1192 } else {
1193 taglen = default_taglen_32 ? 32 : 80;
1194 }
1196 taglen |= 0x0200;
1197 } else if (ast_test_flag(srtp, AST_SRTP_CRYPTO_AES_192)) {
1198 taglen |= 0x0100;
1199 }
1201 taglen |= 0x0080;
1202 }
1203
1204 if (srtp->crypto && (res_sdp_crypto_build_offer(srtp->crypto, taglen) >= 0)) {
1205 return srtp->crypto->a_crypto;
1206 }
1207
1208 ast_log(LOG_WARNING, "No SRTP key management enabled\n");
1209 return NULL;
1210}
1211
1214 .alloc = res_sdp_crypto_alloc,
1215 .build_offer = res_sdp_crypto_build_offer,
1216 .parse_offer = res_sdp_crypto_parse_offer,
1217 .get_attr = res_sdp_srtp_get_attr,
1218};
1219
1220static void res_srtp_shutdown(void)
1221{
1224 srtp_install_event_handler(NULL);
1225#ifdef HAVE_SRTP_SHUTDOWN
1226 srtp_shutdown();
1227#endif
1228 g_initialized = 0;
1229}
1230
1231static int res_srtp_init(void)
1232{
1233 if (g_initialized) {
1234 return 0;
1235 }
1236
1237 if (srtp_init() != err_status_ok) {
1238 ast_log(AST_LOG_WARNING, "Failed to initialize libsrtp\n");
1239 return -1;
1240 }
1241
1242 srtp_install_event_handler(srtp_event_cb);
1243
1245 ast_log(AST_LOG_WARNING, "Failed to register SRTP with rtp engine\n");
1247 return -1;
1248 }
1249
1251 ast_log(AST_LOG_WARNING, "Failed to register SDP SRTP crypto API\n");
1253 return -1;
1254 }
1255
1256#ifdef HAVE_SRTP_GET_VERSION
1257 ast_verb(2, "%s initialized\n", srtp_get_version_string());
1258#else
1259 ast_verb(2, "libsrtp initialized\n");
1260#endif
1261
1262 g_initialized = 1;
1263 return 0;
1264}
1265
1266/*
1267 * Exported functions
1268 */
1269
1270static int load_module(void)
1271{
1272 return res_srtp_init();
1273}
1274
1275static int unload_module(void)
1276{
1278 return 0;
1279}
1280
1282 .support_level = AST_MODULE_SUPPORT_CORE,
1283 .load = load_module,
1284 .unload = unload_module,
1285 .load_pri = AST_MODPRI_CHANNEL_DEPEND,
jack_status_t status
Definition: app_jack.c:146
const char * str
Definition: app_jack.c:147
Asterisk main include file. File version handling, generic pbx functions.
#define ast_free(a)
Definition: astmm.h:180
#define ast_strdupa(s)
duplicate a string in memory from the stack
Definition: astmm.h:298
#define ast_asprintf(ret, fmt,...)
A wrapper for asprintf()
Definition: astmm.h:267
#define ast_calloc(num, len)
A wrapper for calloc()
Definition: astmm.h:202
#define ast_log
Definition: astobj2.c:42
#define ao2_t_ref(o, delta, tag)
Definition: astobj2.h:460
#define ao2_iterator_next(iter)
Definition: astobj2.h:1911
#define OBJ_POINTER
Definition: astobj2.h:1150
@ AO2_ALLOC_OPT_LOCK_MUTEX
Definition: astobj2.h:363
#define ao2_t_find(container, arg, flags, tag)
Definition: astobj2.h:1734
int ao2_container_count(struct ao2_container *c)
Returns the number of elements in a container.
#define ao2_t_link(container, obj, tag)
Definition: astobj2.h:1534
struct ao2_iterator ao2_iterator_init(struct ao2_container *c, int flags) attribute_warn_unused_result
Create an iterator for a container.
#define ao2_t_container_alloc_hash(ao2_options, container_options, n_buckets, hash_fn, sort_fn, cmp_fn, tag)
Definition: astobj2.h:1306
#define ao2_t_unlink(container, obj, tag)
Definition: astobj2.h:1580
void ao2_iterator_destroy(struct ao2_iterator *iter)
Destroy a container iterator.
#define ao2_t_alloc(data_size, destructor_fn, debug_msg)
Definition: astobj2.h:407
@ OBJ_NODATA
Definition: astobj2.h:1044
@ OBJ_MULTIPLE
Definition: astobj2.h:1049
@ OBJ_UNLINK
Definition: astobj2.h:1039
#define ao2_t_callback(c, flags, cb_fn, arg, tag)
Definition: astobj2.h:1696
static int tmp()
Definition: bt_open.c:389
static PGresult * result
Definition: cel_pgsql.c:84
static int match(struct ast_sockaddr *addr, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int check_dcallno)
Definition: chan_iax2.c:2362
char buf[BUFSIZE]
Definition: eagi_proxy.c:66
static int len(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t buflen)
char * strsep(char **str, const char *delims)
Asterisk internal frame definitions.
#define AST_FRIENDLY_OFFSET
Offset into a frame's data buffer.
Support for logging to various files, console and syslog Configuration in file logger....
#define AST_LOG_WARNING
#define ast_debug(level,...)
Log a DEBUG message.
#define LOG_ERROR
#define AST_LOG_NOTICE
#define ast_verb(level,...)
#define LOG_NOTICE
#define LOG_WARNING
#define AST_LIST_NEXT(elm, field)
Returns the next entry in the list after the given entry.
Definition: linkedlists.h:439
int errno
Asterisk module definitions.
@ AST_MODFLAG_LOAD_ORDER
Definition: module.h:331
@ AST_MODFLAG_GLOBAL_SYMBOLS
Definition: module.h:330
#define ast_module_unref(mod)
Release a reference to the module.
Definition: module.h:483
#define ast_module_ref(mod)
Hold a reference to the module.
Definition: module.h:457
#define AST_MODULE_INFO(keystr, flags_to_set, desc, fields...)
Definition: module.h:557
@ AST_MODPRI_CHANNEL_DEPEND
Definition: module.h:340
@ AST_MODULE_SUPPORT_CORE
Definition: module.h:121
#define ASTERISK_GPL_KEY
The text the key() function should return.
Definition: module.h:46
def info(msg)
const char * method
Definition: res_pjsip.c:1279
#define SRTP_MASTER_KEY_LEN
static int policy_cmp_fn(void *obj, void *arg, int flags)
Definition: res_srtp.c:170
static struct ast_sdp_crypto * sdp_crypto_alloc(const int key_len)
Definition: res_srtp.c:681
static void ast_srtp_policy_destroy(struct ast_srtp_policy *policy)
Definition: res_srtp.c:263
static int crypto_activate(struct ast_sdp_crypto *p, int suite_val, unsigned char *remote_key, int key_len, struct ast_rtp_instance *rtp)
Definition: res_srtp.c:752
static int ast_srtp_create(struct ast_srtp **srtp, struct ast_rtp_instance *rtp, struct ast_srtp_policy *policy)
Definition: res_srtp.c:516
static const char * srtp_errstr(int err)
Definition: res_srtp.c:123
static int ast_srtp_policy_set_suite(struct ast_srtp_policy *policy, enum ast_srtp_suite suite)
Definition: res_srtp.c:322
static int ast_srtp_policy_set_master_key(struct ast_srtp_policy *policy, const unsigned char *key, size_t key_len, const unsigned char *salt, size_t salt_len)
Definition: res_srtp.c:327
static int ast_srtp_add_stream(struct ast_srtp *srtp, struct ast_srtp_policy *policy)
Definition: res_srtp.c:575
static int policy_set_suite(crypto_policy_t *p, enum ast_srtp_suite suite)
Definition: res_srtp.c:268
static int set_crypto_policy(struct ast_srtp_policy *policy, int suite_val, const unsigned char *master_key, int key_len, unsigned long ssrc, int inbound)
Definition: res_srtp.c:736
static struct ast_sdp_crypto * res_sdp_crypto_alloc(void)
Definition: res_srtp.c:700
static int ast_srtp_change_source(struct ast_srtp *srtp, unsigned int from_ssrc, unsigned int to_ssrc)
Definition: res_srtp.c:609
static int res_srtp_init(void)
Definition: res_srtp.c:1231
static struct ast_sdp_crypto * crypto_init_keys(struct ast_sdp_crypto *p, const int key_len)
Definition: res_srtp.c:654
static int res_sdp_crypto_parse_offer(struct ast_rtp_instance *rtp, struct ast_sdp_srtp *srtp, const char *attr)
Definition: res_srtp.c:804
static struct ast_srtp * res_srtp_new(void)
Definition: res_srtp.c:189
static int ast_srtp_replace(struct ast_srtp **srtp, struct ast_rtp_instance *rtp, struct ast_srtp_policy *policy)
Definition: res_srtp.c:545
static struct ast_srtp_res srtp_res
Definition: res_srtp.c:103
static int ast_srtp_get_random(unsigned char *key, size_t len)
Definition: res_srtp.c:349
static void ast_srtp_destroy(struct ast_srtp *srtp)
Definition: res_srtp.c:562
static void ast_srtp_policy_set_ssrc(struct ast_srtp_policy *policy, unsigned long ssrc, int inbound)
Definition: res_srtp.c:231
static struct ast_srtp_policy * ast_srtp_policy_alloc(void)
Definition: res_srtp.c:252
static void res_sdp_crypto_dtor(struct ast_sdp_crypto *crypto)
Definition: res_srtp.c:643
static int load_module(void)
Definition: res_srtp.c:1270
static int unload_module(void)
Definition: res_srtp.c:1275
static int policy_hash_fn(const void *obj, const int flags)
Definition: res_srtp.c:163
static struct ast_srtp_policy_res policy_res
Definition: res_srtp.c:115
static struct ast_srtp_policy * find_policy(struct ast_srtp *srtp, const srtp_policy_t *policy, int flags)
Definition: res_srtp.c:177
static int ast_srtp_unprotect(struct ast_srtp *srtp, void *buf, int *len, int rtcp)
Definition: res_srtp.c:369
static void res_srtp_shutdown(void)
Definition: res_srtp.c:1220
static int res_sdp_crypto_build_offer(struct ast_sdp_crypto *p, int taglen)
Definition: res_srtp.c:705
static void srtp_event_cb(srtp_event_data_t *data)
Definition: res_srtp.c:213
static int ast_srtp_protect(struct ast_srtp *srtp, void **buf, int *len, int rtcp)
Definition: res_srtp.c:488
static const char * res_sdp_srtp_get_attr(struct ast_sdp_srtp *srtp, int dtls_enabled, int default_taglen_32)
Definition: res_srtp.c:1101
static struct ast_sdp_crypto_api res_sdp_crypto_api
Definition: res_srtp.c:1212
static void policy_destructor(void *obj)
Definition: res_srtp.c:242
static int g_initialized
Definition: res_srtp.c:82
static void ast_srtp_set_cb(struct ast_srtp *srtp, const struct ast_srtp_cb *cb, void *data)
Definition: res_srtp.c:358
SRTP resource.
ast_srtp_suite
Definition: res_srtp.h:56
@ AST_AES_CM_128_HMAC_SHA1_80
Definition: res_srtp.h:58
@ AST_AES_GCM_256
Definition: res_srtp.h:63
@ AST_AES_GCM_128
Definition: res_srtp.h:62
@ AST_AES_CM_128_HMAC_SHA1_32
Definition: res_srtp.h:59
@ AST_AES_CM_256_HMAC_SHA1_32
Definition: res_srtp.h:61
@ AST_AES_CM_192_HMAC_SHA1_80
Definition: res_srtp.h:66
@ AST_AES_CM_256_HMAC_SHA1_80
Definition: res_srtp.h:60
@ AST_AES_GCM_128_8
Definition: res_srtp.h:64
@ AST_AES_CM_192_HMAC_SHA1_32
Definition: res_srtp.h:67
@ AST_AES_GCM_256_8
Definition: res_srtp.h:65
#define NULL
Definition: resample.c:96
Pluggable RTP Architecture.
int ast_rtp_engine_register_srtp(struct ast_srtp_res *srtp_res, struct ast_srtp_policy_res *policy_res)
Definition: rtp_engine.c:2910
void ast_rtp_engine_unregister_srtp(void)
Definition: rtp_engine.c:2925
@ AST_RTP_INSTANCE_STAT_LOCAL_SSRC
Definition: rtp_engine.h:249
@ AST_RTP_INSTANCE_STAT_REMOTE_SSRC
Definition: rtp_engine.h:251
int ast_rtp_instance_get_stats(struct ast_rtp_instance *instance, struct ast_rtp_instance_stats *stats, enum ast_rtp_instance_stat stat)
Retrieve statistics about an RTP instance.
Definition: rtp_engine.c:2622
unsigned int ast_rtp_instance_get_ssrc(struct ast_rtp_instance *rtp)
Retrieve the local SSRC value that we will be using.
Definition: rtp_engine.c:4011
int ast_rtp_instance_add_srtp_policy(struct ast_rtp_instance *instance, struct ast_srtp_policy *remote_policy, struct ast_srtp_policy *local_policy, int rtcp)
Add or replace the SRTP policies for the given RTP instance.
Definition: rtp_engine.c:2936
SRTP and SDP Security descriptions.
int ast_sdp_crypto_register(struct ast_sdp_crypto_api *api)
Register SDP SRTP crypto processing routines.
Definition: sdp_srtp.c:123
struct ast_sdp_srtp * ast_sdp_srtp_alloc(void)
allocate a ast_sdp_srtp structure
Definition: sdp_srtp.c:41
#define AST_SRTP_CRYPTO_TAG_16
Definition: sdp_srtp.h:48
#define AST_SRTP_CRYPTO_TAG_80
Definition: sdp_srtp.h:47
#define AST_SRTP_CRYPTO_AES_256
Definition: sdp_srtp.h:51
#define AST_SRTP_CRYPTO_TAG_32
Definition: sdp_srtp.h:46
void ast_sdp_crypto_unregister(struct ast_sdp_crypto_api *api)
Unregister SDP SRTP crypto processing routines.
Definition: sdp_srtp.c:132
#define AST_SRTP_CRYPTO_TAG_8
Definition: sdp_srtp.h:49
#define AST_SRTP_CRYPTO_AES_192
Definition: sdp_srtp.h:50
#define AST_SRTP_CRYPTO_OLD_NAME
Definition: sdp_srtp.h:52
#define AST_SRTP_CRYPTO_OFFER_OK
Definition: sdp_srtp.h:45
#define err_status_cipher_fail
Definition: srtp_compat.h:40
#define crypto_policy_set_aes_gcm_256_8_auth
Definition: srtp_compat.h:17
#define crypto_policy_set_aes_cm_192_hmac_sha1_80
Definition: srtp_compat.h:10
#define crypto_policy_set_aes_gcm_128_16_auth
Definition: srtp_compat.h:14
#define err_status_ok
Definition: srtp_compat.h:32
#define crypto_policy_set_aes_cm_128_hmac_sha1_32
Definition: srtp_compat.h:9
#define crypto_policy_set_aes_cm_128_hmac_sha1_80
Definition: srtp_compat.h:8
#define err_status_init_fail
Definition: srtp_compat.h:37
#define err_status_replay_old
Definition: srtp_compat.h:42
#define err_status_algo_fail
Definition: srtp_compat.h:43
#define crypto_policy_set_aes_gcm_256_16_auth
Definition: srtp_compat.h:15
#define AES_128_GCM_KEYSIZE_WSALT
Definition: srtp_compat.h:22
#define err_status_no_ctx
Definition: srtp_compat.h:45
#define crypto_policy_set_aes_cm_192_hmac_sha1_32
Definition: srtp_compat.h:11
#define err_status_dealloc_fail
Definition: srtp_compat.h:36
#define crypto_policy_set_aes_cm_256_hmac_sha1_32
Definition: srtp_compat.h:13
#define crypto_policy_set_aes_cm_256_hmac_sha1_80
Definition: srtp_compat.h:12
#define err_status_alloc_fail
Definition: srtp_compat.h:35
#define err_status_no_such_op
Definition: srtp_compat.h:44
#define err_status_key_expired
Definition: srtp_compat.h:47
#define AES_256_GCM_KEYSIZE_WSALT
Definition: srtp_compat.h:28
#define err_status_t
Definition: srtp_compat.h:31
#define crypto_policy_set_aes_gcm_128_8_auth
Definition: srtp_compat.h:16
#define err_status_cant_check
Definition: srtp_compat.h:46
#define err_status_bad_param
Definition: srtp_compat.h:34
#define err_status_auth_fail
Definition: srtp_compat.h:39
#define err_status_terminus
Definition: srtp_compat.h:38
#define err_status_replay_fail
Definition: srtp_compat.h:41
#define err_status_fail
Definition: srtp_compat.h:33
#define crypto_policy_t
Definition: srtp_compat.h:6
static force_inline int attribute_pure ast_strlen_zero(const char *s)
Definition: strings.h:65
Generic container type.
When we need to walk through a container, we use an ao2_iterator to keep track of the current positio...
Definition: astobj2.h:1821
struct ast_module * self
Definition: module.h:356
unsigned int remote_ssrc
Definition: rtp_engine.h:454
unsigned int local_ssrc
Definition: rtp_engine.h:452
sdp_crypto_destroy_cb dtor
Definition: sdp_srtp.h:128
char * a_crypto
Definition: res_srtp.c:635
unsigned char local_key[SRTP_MAX_KEY_LEN]
Definition: res_srtp.c:636
char local_key64[((SRTP_MAX_KEY_LEN) *8+5)/6+1]
Definition: res_srtp.c:638
unsigned char remote_key[SRTP_MAX_KEY_LEN]
Definition: res_srtp.c:639
structure for secure RTP audio
Definition: sdp_srtp.h:38
struct ast_sdp_srtp::@278 sdp_srtp_list
struct ast_sdp_crypto * crypto
Definition: sdp_srtp.h:40
unsigned int flags
Definition: sdp_srtp.h:39
int(* no_ctx)(struct ast_rtp_instance *rtp, unsigned long ssrc, void *data)
Definition: res_srtp.h:31
void(* destroy)(struct ast_srtp_policy *policy)
Definition: res_srtp.h:72
int(* set_master_key)(struct ast_srtp_policy *policy, const unsigned char *key, size_t key_len, const unsigned char *salt, size_t salt_len)
Definition: res_srtp.h:74
void(* set_ssrc)(struct ast_srtp_policy *policy, unsigned long ssrc, int inbound)
Definition: res_srtp.h:75
int(* set_suite)(struct ast_srtp_policy *policy, enum ast_srtp_suite suite)
Definition: res_srtp.h:73
struct ast_srtp_policy *(* alloc)(void)
Definition: res_srtp.h:71
srtp_policy_t sp
Definition: res_srtp.c:78
int(* get_random)(unsigned char *key, size_t len)
Definition: res_srtp.h:52
int(* create)(struct ast_srtp **srtp, struct ast_rtp_instance *rtp, struct ast_srtp_policy *policy)
Definition: res_srtp.h:36
unsigned char buf[8192+AST_FRIENDLY_OFFSET]
Definition: res_srtp.c:73
struct ao2_container * policies
Definition: res_srtp.c:68
srtp_t session
Definition: res_srtp.c:69
void * data
Definition: res_srtp.c:71
const struct ast_srtp_cb * cb
Definition: res_srtp.c:70
int warned
Definition: res_srtp.c:72
struct ast_rtp_instance * rtp
Definition: res_srtp.c:67
unsigned char rtcpbuf[8192+AST_FRIENDLY_OFFSET]
Definition: res_srtp.c:74
Utility functions.
#define ast_test_flag(p, flag)
Definition: utils.h:63
int ast_base64decode(unsigned char *dst, const char *src, int max)
Decode data from base64.
Definition: utils.c:296
int ast_base64encode(char *dst, const unsigned char *src, int srclen, int max)
Encode data in base64.
Definition: utils.c:406
#define ast_clear_flag(p, flag)
Definition: utils.h:77
#define ast_set_flag(p, flag)
Definition: utils.h:70
#define ARRAY_LEN(a)
Definition: utils.h:666