1 /* $OpenBSD: d1_srtp.c,v 1.14 2015/07/17 17:36:24 doug Exp $ */ 2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 /* ==================================================================== 59 * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved. 60 * 61 * Redistribution and use in source and binary forms, with or without 62 * modification, are permitted provided that the following conditions 63 * are met: 64 * 65 * 1. Redistributions of source code must retain the above copyright 66 * notice, this list of conditions and the following disclaimer. 67 * 68 * 2. Redistributions in binary form must reproduce the above copyright 69 * notice, this list of conditions and the following disclaimer in 70 * the documentation and/or other materials provided with the 71 * distribution. 72 * 73 * 3. All advertising materials mentioning features or use of this 74 * software must display the following acknowledgment: 75 * "This product includes software developed by the OpenSSL Project 76 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 77 * 78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 79 * endorse or promote products derived from this software without 80 * prior written permission. For written permission, please contact 81 * openssl-core@openssl.org. 82 * 83 * 5. Products derived from this software may not be called "OpenSSL" 84 * nor may "OpenSSL" appear in their names without prior written 85 * permission of the OpenSSL Project. 86 * 87 * 6. Redistributions of any form whatsoever must retain the following 88 * acknowledgment: 89 * "This product includes software developed by the OpenSSL Project 90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 91 * 92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 95 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 103 * OF THE POSSIBILITY OF SUCH DAMAGE. 104 * ==================================================================== 105 * 106 * This product includes cryptographic software written by Eric Young 107 * (eay@cryptsoft.com). This product includes software written by Tim 108 * Hudson (tjh@cryptsoft.com). 109 * 110 */ 111 /* 112 * DTLS code by Eric Rescorla <ekr@rtfm.com> 113 * 114 * Copyright (C) 2006, Network Resonance, Inc. 115 * Copyright (C) 2011, RTFM, Inc. 116 */ 117 118 #include <stdio.h> 119 120 #include <openssl/objects.h> 121 122 #include "ssl_locl.h" 123 124 #ifndef OPENSSL_NO_SRTP 125 126 #include "bytestring.h" 127 #include "srtp.h" 128 129 static SRTP_PROTECTION_PROFILE srtp_known_profiles[] = { 130 { 131 "SRTP_AES128_CM_SHA1_80", 132 SRTP_AES128_CM_SHA1_80, 133 }, 134 { 135 "SRTP_AES128_CM_SHA1_32", 136 SRTP_AES128_CM_SHA1_32, 137 }, 138 {0} 139 }; 140 141 static int 142 find_profile_by_name(char *profile_name, SRTP_PROTECTION_PROFILE **pptr, 143 unsigned len) 144 { 145 SRTP_PROTECTION_PROFILE *p; 146 147 p = srtp_known_profiles; 148 while (p->name) { 149 if ((len == strlen(p->name)) && 150 !strncmp(p->name, profile_name, len)) { 151 *pptr = p; 152 return 0; 153 } 154 155 p++; 156 } 157 158 return 1; 159 } 160 161 static int 162 find_profile_by_num(unsigned profile_num, SRTP_PROTECTION_PROFILE **pptr) 163 { 164 SRTP_PROTECTION_PROFILE *p; 165 166 p = srtp_known_profiles; 167 while (p->name) { 168 if (p->id == profile_num) { 169 *pptr = p; 170 return 0; 171 } 172 p++; 173 } 174 175 return 1; 176 } 177 178 static int 179 ssl_ctx_make_profiles(const char *profiles_string, 180 STACK_OF(SRTP_PROTECTION_PROFILE) **out) 181 { 182 STACK_OF(SRTP_PROTECTION_PROFILE) *profiles; 183 184 char *col; 185 char *ptr = (char *)profiles_string; 186 187 SRTP_PROTECTION_PROFILE *p; 188 189 if (!(profiles = sk_SRTP_PROTECTION_PROFILE_new_null())) { 190 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES, 191 SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES); 192 return 1; 193 } 194 195 do { 196 col = strchr(ptr, ':'); 197 198 if (!find_profile_by_name(ptr, &p, 199 col ? col - ptr : (int)strlen(ptr))) { 200 sk_SRTP_PROTECTION_PROFILE_push(profiles, p); 201 } else { 202 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES, 203 SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE); 204 sk_SRTP_PROTECTION_PROFILE_free(profiles); 205 return 1; 206 } 207 208 if (col) 209 ptr = col + 1; 210 } while (col); 211 212 *out = profiles; 213 214 return 0; 215 } 216 217 int 218 SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx, const char *profiles) 219 { 220 return ssl_ctx_make_profiles(profiles, &ctx->srtp_profiles); 221 } 222 223 int 224 SSL_set_tlsext_use_srtp(SSL *s, const char *profiles) 225 { 226 return ssl_ctx_make_profiles(profiles, &s->srtp_profiles); 227 } 228 229 230 STACK_OF(SRTP_PROTECTION_PROFILE) * 231 SSL_get_srtp_profiles(SSL *s) 232 { 233 if (s != NULL) { 234 if (s->srtp_profiles != NULL) { 235 return s->srtp_profiles; 236 } else if ((s->ctx != NULL) && 237 (s->ctx->srtp_profiles != NULL)) { 238 return s->ctx->srtp_profiles; 239 } 240 } 241 242 return NULL; 243 } 244 245 SRTP_PROTECTION_PROFILE * 246 SSL_get_selected_srtp_profile(SSL *s) 247 { 248 return s->srtp_profile; 249 } 250 251 /* Note: this function returns 0 length if there are no 252 profiles specified */ 253 int 254 ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len, int maxlen) 255 { 256 int ct = 0; 257 int i; 258 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0; 259 SRTP_PROTECTION_PROFILE *prof; 260 261 clnt = SSL_get_srtp_profiles(s); 262 263 ct = sk_SRTP_PROTECTION_PROFILE_num(clnt); /* -1 if clnt == 0 */ 264 265 if (p) { 266 if (ct == 0) { 267 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT, 268 SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST); 269 return 1; 270 } 271 272 if ((2 + ct * 2 + 1) > maxlen) { 273 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT, 274 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG); 275 return 1; 276 } 277 278 /* Add the length */ 279 s2n(ct * 2, p); 280 for (i = 0; i < ct; i++) { 281 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i); 282 s2n(prof->id, p); 283 } 284 285 /* Add an empty use_mki value */ 286 *p++ = 0; 287 } 288 289 *len = 2 + ct*2 + 1; 290 291 return 0; 292 } 293 294 295 int 296 ssl_parse_clienthello_use_srtp_ext(SSL *s, const unsigned char *d, int len, 297 int *al) 298 { 299 SRTP_PROTECTION_PROFILE *cprof, *sprof; 300 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0, *srvr; 301 int i, j; 302 int ret = 1; 303 uint16_t id; 304 CBS cbs, ciphers, mki; 305 306 if (len < 0) { 307 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT, 308 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 309 *al = SSL_AD_DECODE_ERROR; 310 goto done; 311 } 312 313 CBS_init(&cbs, d, len); 314 /* Pull off the cipher suite list */ 315 if (!CBS_get_u16_length_prefixed(&cbs, &ciphers) || 316 CBS_len(&ciphers) % 2) { 317 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT, 318 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 319 *al = SSL_AD_DECODE_ERROR; 320 goto done; 321 } 322 323 clnt = sk_SRTP_PROTECTION_PROFILE_new_null(); 324 325 while (CBS_len(&ciphers) > 0) { 326 if (!CBS_get_u16(&ciphers, &id)) { 327 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT, 328 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 329 *al = SSL_AD_DECODE_ERROR; 330 goto done; 331 } 332 333 if (!find_profile_by_num(id, &cprof)) 334 sk_SRTP_PROTECTION_PROFILE_push(clnt, cprof); 335 else 336 ; /* Ignore */ 337 } 338 339 /* Extract the MKI value as a sanity check, but discard it for now. */ 340 if (!CBS_get_u8_length_prefixed(&cbs, &mki) || 341 CBS_len(&cbs) != 0) { 342 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT, 343 SSL_R_BAD_SRTP_MKI_VALUE); 344 *al = SSL_AD_DECODE_ERROR; 345 goto done; 346 } 347 348 srvr = SSL_get_srtp_profiles(s); 349 350 /* 351 * Pick our most preferred profile. If no profiles have been 352 * configured then the outer loop doesn't run 353 * (sk_SRTP_PROTECTION_PROFILE_num() = -1) 354 * and so we just return without doing anything. 355 */ 356 for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(srvr); i++) { 357 sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i); 358 359 for (j = 0; j < sk_SRTP_PROTECTION_PROFILE_num(clnt); j++) { 360 cprof = sk_SRTP_PROTECTION_PROFILE_value(clnt, j); 361 362 if (cprof->id == sprof->id) { 363 s->srtp_profile = sprof; 364 *al = 0; 365 ret = 0; 366 goto done; 367 } 368 } 369 } 370 371 ret = 0; 372 373 done: 374 if (clnt) 375 sk_SRTP_PROTECTION_PROFILE_free(clnt); 376 377 return ret; 378 } 379 380 int 381 ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len, int maxlen) 382 { 383 if (p) { 384 if (maxlen < 5) { 385 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT, 386 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG); 387 return 1; 388 } 389 390 if (s->srtp_profile == 0) { 391 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT, 392 SSL_R_USE_SRTP_NOT_NEGOTIATED); 393 return 1; 394 } 395 s2n(2, p); 396 s2n(s->srtp_profile->id, p); 397 *p++ = 0; 398 } 399 *len = 5; 400 401 return 0; 402 } 403 404 405 int 406 ssl_parse_serverhello_use_srtp_ext(SSL *s, const unsigned char *d, int len, int *al) 407 { 408 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt; 409 SRTP_PROTECTION_PROFILE *prof; 410 int i; 411 uint16_t id; 412 CBS cbs, profile_ids, mki; 413 414 if (len < 0) { 415 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 416 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 417 *al = SSL_AD_DECODE_ERROR; 418 return 1; 419 } 420 421 CBS_init(&cbs, d, len); 422 423 /* 424 * As per RFC 5764 section 4.1.1, server response MUST be a single 425 * profile id. 426 */ 427 if (!CBS_get_u16_length_prefixed(&cbs, &profile_ids) || 428 !CBS_get_u16(&profile_ids, &id) || CBS_len(&profile_ids) != 0) { 429 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 430 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 431 *al = SSL_AD_DECODE_ERROR; 432 return 1; 433 } 434 435 /* Must be no MKI, since we never offer one. */ 436 if (!CBS_get_u8_length_prefixed(&cbs, &mki) || CBS_len(&mki) != 0) { 437 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 438 SSL_R_BAD_SRTP_MKI_VALUE); 439 *al = SSL_AD_ILLEGAL_PARAMETER; 440 return 1; 441 } 442 443 clnt = SSL_get_srtp_profiles(s); 444 445 /* Throw an error if the server gave us an unsolicited extension. */ 446 if (clnt == NULL) { 447 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 448 SSL_R_NO_SRTP_PROFILES); 449 *al = SSL_AD_DECODE_ERROR; 450 return 1; 451 } 452 453 /* 454 * Check to see if the server gave us something we support 455 * (and presumably offered). 456 */ 457 for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) { 458 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i); 459 460 if (prof->id == id) { 461 s->srtp_profile = prof; 462 *al = 0; 463 return 0; 464 } 465 } 466 467 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 468 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 469 *al = SSL_AD_DECODE_ERROR; 470 return 1; 471 } 472 473 #endif 474