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, size_t 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 ? (size_t)(col - 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;
140 int ssl_parse_clienthello_use_srtp_ext(SSL *s, PACKET *pkt, int *al)
142 SRTP_PROTECTION_PROFILE *sprof;
143 STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
144 unsigned int ct, mki_len, id;
148 /* Pull off the length of the cipher suite list and check it is even */
149 if (!PACKET_get_net_2(pkt, &ct)
150 || (ct & 1) != 0 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
151 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
152 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
153 *al = SSL_AD_DECODE_ERROR;
157 srvr = SSL_get_srtp_profiles(s);
158 s->srtp_profile = NULL;
159 /* Search all profiles for a match initially */
160 srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
162 while (PACKET_remaining(&subpkt)) {
163 if (!PACKET_get_net_2(&subpkt, &id)) {
164 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
165 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
166 *al = SSL_AD_DECODE_ERROR;
171 * Only look for match in profiles of higher preference than
173 * If no profiles have been have been configured then this
176 for (i = 0; i < srtp_pref; i++) {
177 sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
178 if (sprof->id == id) {
179 s->srtp_profile = sprof;
187 * Now extract the MKI value as a sanity check, but discard it for now
189 if (!PACKET_get_1(pkt, &mki_len)) {
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 if (!PACKET_forward(pkt, mki_len)
197 || PACKET_remaining(pkt)) {
198 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
199 SSL_R_BAD_SRTP_MKI_VALUE);
200 *al = SSL_AD_DECODE_ERROR;
207 int ssl_parse_serverhello_use_srtp_ext(SSL *s, PACKET *pkt, int *al)
209 unsigned int id, ct, mki;
212 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt;
213 SRTP_PROTECTION_PROFILE *prof;
215 if (!PACKET_get_net_2(pkt, &ct)
216 || ct != 2 || !PACKET_get_net_2(pkt, &id)
217 || !PACKET_get_1(pkt, &mki)
218 || PACKET_remaining(pkt) != 0) {
219 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
220 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
221 *al = SSL_AD_DECODE_ERROR;
226 /* Must be no MKI, since we never offer one */
227 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
228 SSL_R_BAD_SRTP_MKI_VALUE);
229 *al = SSL_AD_ILLEGAL_PARAMETER;
233 clnt = SSL_get_srtp_profiles(s);
235 /* Throw an error if the server gave us an unsolicited extension */
237 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
238 SSL_R_NO_SRTP_PROFILES);
239 *al = SSL_AD_DECODE_ERROR;
244 * Check to see if the server gave us something we support (and
245 * presumably offered)
247 for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) {
248 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
250 if (prof->id == id) {
251 s->srtp_profile = prof;
257 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
258 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
259 *al = SSL_AD_DECODE_ERROR;