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",
36 "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,
80 col ? col - ptr : (int)strlen(ptr))) {
81 if (sk_SRTP_PROTECTION_PROFILE_find(profiles, p) >= 0) {
82 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
83 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
87 if (!sk_SRTP_PROTECTION_PROFILE_push(profiles, p)) {
88 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
89 SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES);
93 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
94 SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE);
102 sk_SRTP_PROTECTION_PROFILE_free(*out);
108 sk_SRTP_PROTECTION_PROFILE_free(profiles);
112 int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx, const char *profiles)
114 return ssl_ctx_make_profiles(profiles, &ctx->srtp_profiles);
117 int SSL_set_tlsext_use_srtp(SSL *s, const char *profiles)
119 return ssl_ctx_make_profiles(profiles, &s->srtp_profiles);
122 STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(SSL *s)
125 if (s->srtp_profiles != NULL) {
126 return s->srtp_profiles;
127 } else if ((s->ctx != NULL) && (s->ctx->srtp_profiles != NULL)) {
128 return s->ctx->srtp_profiles;
135 SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(SSL *s)
137 return s->srtp_profile;
141 * Note: this function returns 0 length if there are no profiles specified
143 int ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
148 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0;
149 SRTP_PROTECTION_PROFILE *prof;
151 clnt = SSL_get_srtp_profiles(s);
152 ct = sk_SRTP_PROTECTION_PROFILE_num(clnt); /* -1 if clnt == 0 */
156 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
157 SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);
161 if ((2 + ct * 2 + 1) > maxlen) {
162 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
163 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
169 for (i = 0; i < ct; i++) {
170 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
174 /* Add an empty use_mki value */
178 *len = 2 + ct * 2 + 1;
183 int ssl_parse_clienthello_use_srtp_ext(SSL *s, PACKET *pkt, int *al)
185 SRTP_PROTECTION_PROFILE *sprof;
186 STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
187 unsigned int ct, mki_len, id;
191 /* Pull off the length of the cipher suite list and check it is even */
192 if (!PACKET_get_net_2(pkt, &ct)
194 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
195 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
196 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
197 *al = SSL_AD_DECODE_ERROR;
201 srvr = SSL_get_srtp_profiles(s);
202 s->srtp_profile = NULL;
203 /* Search all profiles for a match initially */
204 srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
206 while (PACKET_remaining(&subpkt)) {
207 if (!PACKET_get_net_2(&subpkt, &id)) {
208 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
209 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
210 *al = SSL_AD_DECODE_ERROR;
215 * Only look for match in profiles of higher preference than
217 * If no profiles have been have been configured then this
220 for (i = 0; i < srtp_pref; i++) {
221 sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
222 if (sprof->id == id) {
223 s->srtp_profile = sprof;
231 * Now extract the MKI value as a sanity check, but discard it for now
233 if (!PACKET_get_1(pkt, &mki_len)) {
234 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
235 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
236 *al = SSL_AD_DECODE_ERROR;
240 if (!PACKET_forward(pkt, mki_len)
241 || PACKET_remaining(pkt)) {
242 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
243 SSL_R_BAD_SRTP_MKI_VALUE);
244 *al = SSL_AD_DECODE_ERROR;
251 int ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
256 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
257 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
261 if (s->srtp_profile == 0) {
262 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
263 SSL_R_USE_SRTP_NOT_NEGOTIATED);
267 s2n(s->srtp_profile->id, p);
275 int ssl_parse_serverhello_use_srtp_ext(SSL *s, PACKET *pkt, int *al)
277 unsigned int id, ct, mki;
280 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt;
281 SRTP_PROTECTION_PROFILE *prof;
283 if (!PACKET_get_net_2(pkt, &ct)
285 || !PACKET_get_net_2(pkt, &id)
286 || !PACKET_get_1(pkt, &mki)
287 || PACKET_remaining(pkt) != 0) {
288 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
289 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
290 *al = SSL_AD_DECODE_ERROR;
295 /* Must be no MKI, since we never offer one */
296 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
297 SSL_R_BAD_SRTP_MKI_VALUE);
298 *al = SSL_AD_ILLEGAL_PARAMETER;
302 clnt = SSL_get_srtp_profiles(s);
304 /* Throw an error if the server gave us an unsolicited extension */
306 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
307 SSL_R_NO_SRTP_PROFILES);
308 *al = SSL_AD_DECODE_ERROR;
313 * Check to see if the server gave us something we support (and
314 * presumably offered)
316 for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) {
317 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
319 if (prof->id == id) {
320 s->srtp_profile = prof;
326 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
327 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
328 *al = SSL_AD_DECODE_ERROR;