2 * Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 * DTLS code by Eric Rescorla <ekr@rtfm.com>
13 * Copyright (C) 2006, Network Resonance, Inc. Copyright (C) 2011, RTFM, Inc.
17 #include <openssl/objects.h>
20 #ifndef OPENSSL_NO_SRTP
22 static SRTP_PROTECTION_PROFILE srtp_known_profiles[] = {
24 "SRTP_AES128_CM_SHA1_80",
25 SRTP_AES128_CM_SHA1_80,
28 "SRTP_AES128_CM_SHA1_32",
29 SRTP_AES128_CM_SHA1_32,
32 "SRTP_AEAD_AES_128_GCM",
33 SRTP_AEAD_AES_128_GCM,
36 "SRTP_AEAD_AES_256_GCM",
37 SRTP_AEAD_AES_256_GCM,
42 static int find_profile_by_name(char *profile_name,
43 SRTP_PROTECTION_PROFILE **pptr, unsigned len)
45 SRTP_PROTECTION_PROFILE *p;
47 p = srtp_known_profiles;
49 if ((len == strlen(p->name))
50 && strncmp(p->name, profile_name, len) == 0) {
61 static int ssl_ctx_make_profiles(const char *profiles_string,
62 STACK_OF(SRTP_PROTECTION_PROFILE) **out)
64 STACK_OF(SRTP_PROTECTION_PROFILE) *profiles;
67 char *ptr = (char *)profiles_string;
68 SRTP_PROTECTION_PROFILE *p;
70 if ((profiles = sk_SRTP_PROTECTION_PROFILE_new_null()) == NULL) {
71 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
72 SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES);
77 col = strchr(ptr, ':');
79 if (!find_profile_by_name(ptr, &p, col ? col - ptr : (int)strlen(ptr))) {
80 if (sk_SRTP_PROTECTION_PROFILE_find(profiles, p) >= 0) {
81 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
82 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
86 if (!sk_SRTP_PROTECTION_PROFILE_push(profiles, p)) {
87 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
88 SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES);
92 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
93 SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE);
101 sk_SRTP_PROTECTION_PROFILE_free(*out);
107 sk_SRTP_PROTECTION_PROFILE_free(profiles);
111 int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx, const char *profiles)
113 return ssl_ctx_make_profiles(profiles, &ctx->srtp_profiles);
116 int SSL_set_tlsext_use_srtp(SSL *s, const char *profiles)
118 return ssl_ctx_make_profiles(profiles, &s->srtp_profiles);
121 STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(SSL *s)
124 if (s->srtp_profiles != NULL) {
125 return s->srtp_profiles;
126 } else if ((s->ctx != NULL) && (s->ctx->srtp_profiles != NULL)) {
127 return s->ctx->srtp_profiles;
134 SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(SSL *s)
136 return s->srtp_profile;
140 * Note: this function returns 0 length if there are no profiles specified
142 int ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
147 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0;
148 SRTP_PROTECTION_PROFILE *prof;
150 clnt = SSL_get_srtp_profiles(s);
151 ct = sk_SRTP_PROTECTION_PROFILE_num(clnt); /* -1 if clnt == 0 */
155 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
156 SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);
160 if ((2 + ct * 2 + 1) > maxlen) {
161 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
162 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
168 for (i = 0; i < ct; i++) {
169 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
173 /* Add an empty use_mki value */
177 *len = 2 + ct * 2 + 1;
182 int ssl_parse_clienthello_use_srtp_ext(SSL *s, PACKET *pkt, int *al)
184 SRTP_PROTECTION_PROFILE *sprof;
185 STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
186 unsigned int ct, mki_len, id;
190 /* Pull off the length of the cipher suite list and check it is even */
191 if (!PACKET_get_net_2(pkt, &ct)
192 || (ct & 1) != 0 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
193 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
194 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
195 *al = SSL_AD_DECODE_ERROR;
199 srvr = SSL_get_srtp_profiles(s);
200 s->srtp_profile = NULL;
201 /* Search all profiles for a match initially */
202 srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
204 while (PACKET_remaining(&subpkt)) {
205 if (!PACKET_get_net_2(&subpkt, &id)) {
206 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
207 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
208 *al = SSL_AD_DECODE_ERROR;
213 * Only look for match in profiles of higher preference than
215 * If no profiles have been have been configured then this
218 for (i = 0; i < srtp_pref; i++) {
219 sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
220 if (sprof->id == id) {
221 s->srtp_profile = sprof;
229 * Now extract the MKI value as a sanity check, but discard it for now
231 if (!PACKET_get_1(pkt, &mki_len)) {
232 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
233 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
234 *al = SSL_AD_DECODE_ERROR;
238 if (!PACKET_forward(pkt, mki_len)
239 || PACKET_remaining(pkt)) {
240 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
241 SSL_R_BAD_SRTP_MKI_VALUE);
242 *al = SSL_AD_DECODE_ERROR;
249 int ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
254 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
255 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
259 if (s->srtp_profile == 0) {
260 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
261 SSL_R_USE_SRTP_NOT_NEGOTIATED);
265 s2n(s->srtp_profile->id, p);
273 int ssl_parse_serverhello_use_srtp_ext(SSL *s, PACKET *pkt, int *al)
275 unsigned int id, ct, mki;
278 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt;
279 SRTP_PROTECTION_PROFILE *prof;
281 if (!PACKET_get_net_2(pkt, &ct)
282 || ct != 2 || !PACKET_get_net_2(pkt, &id)
283 || !PACKET_get_1(pkt, &mki)
284 || PACKET_remaining(pkt) != 0) {
285 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
286 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
287 *al = SSL_AD_DECODE_ERROR;
292 /* Must be no MKI, since we never offer one */
293 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
294 SSL_R_BAD_SRTP_MKI_VALUE);
295 *al = SSL_AD_ILLEGAL_PARAMETER;
299 clnt = SSL_get_srtp_profiles(s);
301 /* Throw an error if the server gave us an unsolicited extension */
303 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
304 SSL_R_NO_SRTP_PROFILES);
305 *al = SSL_AD_DECODE_ERROR;
310 * Check to see if the server gave us something we support (and
311 * presumably offered)
313 for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) {
314 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
316 if (prof->id == id) {
317 s->srtp_profile = prof;
323 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
324 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
325 *al = SSL_AD_DECODE_ERROR;