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);
84 sk_SRTP_PROTECTION_PROFILE_free(profiles);
88 sk_SRTP_PROTECTION_PROFILE_push(profiles, p);
90 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
91 SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE);
92 sk_SRTP_PROTECTION_PROFILE_free(profiles);
100 sk_SRTP_PROTECTION_PROFILE_free(*out);
107 int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx, const char *profiles)
109 return ssl_ctx_make_profiles(profiles, &ctx->srtp_profiles);
112 int SSL_set_tlsext_use_srtp(SSL *s, const char *profiles)
114 return ssl_ctx_make_profiles(profiles, &s->srtp_profiles);
117 STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(SSL *s)
120 if (s->srtp_profiles != NULL) {
121 return s->srtp_profiles;
122 } else if ((s->ctx != NULL) && (s->ctx->srtp_profiles != NULL)) {
123 return s->ctx->srtp_profiles;
130 SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(SSL *s)
132 return s->srtp_profile;
136 * Note: this function returns 0 length if there are no profiles specified
138 int ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
143 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0;
144 SRTP_PROTECTION_PROFILE *prof;
146 clnt = SSL_get_srtp_profiles(s);
147 ct = sk_SRTP_PROTECTION_PROFILE_num(clnt); /* -1 if clnt == 0 */
151 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
152 SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);
156 if ((2 + ct * 2 + 1) > maxlen) {
157 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
158 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
164 for (i = 0; i < ct; i++) {
165 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
169 /* Add an empty use_mki value */
173 *len = 2 + ct * 2 + 1;
178 int ssl_parse_clienthello_use_srtp_ext(SSL *s, PACKET *pkt, int *al)
180 SRTP_PROTECTION_PROFILE *sprof;
181 STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
182 unsigned int ct, mki_len, id;
186 /* Pull off the length of the cipher suite list and check it is even */
187 if (!PACKET_get_net_2(pkt, &ct)
189 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
190 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
191 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
192 *al = SSL_AD_DECODE_ERROR;
196 srvr = SSL_get_srtp_profiles(s);
197 s->srtp_profile = NULL;
198 /* Search all profiles for a match initially */
199 srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
201 while (PACKET_remaining(&subpkt)) {
202 if (!PACKET_get_net_2(&subpkt, &id)) {
203 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
204 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
205 *al = SSL_AD_DECODE_ERROR;
210 * Only look for match in profiles of higher preference than
212 * If no profiles have been have been configured then this
215 for (i = 0; i < srtp_pref; i++) {
216 sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
217 if (sprof->id == id) {
218 s->srtp_profile = sprof;
226 * Now extract the MKI value as a sanity check, but discard it for now
228 if (!PACKET_get_1(pkt, &mki_len)) {
229 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
230 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
231 *al = SSL_AD_DECODE_ERROR;
235 if (!PACKET_forward(pkt, mki_len)
236 || PACKET_remaining(pkt)) {
237 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
238 SSL_R_BAD_SRTP_MKI_VALUE);
239 *al = SSL_AD_DECODE_ERROR;
246 int ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
251 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
252 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
256 if (s->srtp_profile == 0) {
257 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
258 SSL_R_USE_SRTP_NOT_NEGOTIATED);
262 s2n(s->srtp_profile->id, p);
270 int ssl_parse_serverhello_use_srtp_ext(SSL *s, PACKET *pkt, int *al)
272 unsigned int id, ct, mki;
275 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt;
276 SRTP_PROTECTION_PROFILE *prof;
278 if (!PACKET_get_net_2(pkt, &ct)
280 || !PACKET_get_net_2(pkt, &id)
281 || !PACKET_get_1(pkt, &mki)
282 || PACKET_remaining(pkt) != 0) {
283 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
284 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
285 *al = SSL_AD_DECODE_ERROR;
290 /* Must be no MKI, since we never offer one */
291 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
292 SSL_R_BAD_SRTP_MKI_VALUE);
293 *al = SSL_AD_ILLEGAL_PARAMETER;
297 clnt = SSL_get_srtp_profiles(s);
299 /* Throw an error if the server gave us an unsolicited extension */
301 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
302 SSL_R_NO_SRTP_PROFILES);
303 *al = SSL_AD_DECODE_ERROR;
308 * Check to see if the server gave us something we support (and
309 * presumably offered)
311 for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) {
312 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
314 if (prof->id == id) {
315 s->srtp_profile = prof;
321 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
322 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
323 *al = SSL_AD_DECODE_ERROR;