1 /* $OpenBSD: d1_srtp.c,v 1.8 2014/07/14 08:21:47 miod 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 #include <openssl/objects.h> 120 #include "ssl_locl.h" 121 122 #ifndef OPENSSL_NO_SRTP 123 124 #include "srtp.h" 125 126 127 static SRTP_PROTECTION_PROFILE srtp_known_profiles[] = { 128 { 129 "SRTP_AES128_CM_SHA1_80", 130 SRTP_AES128_CM_SHA1_80, 131 }, 132 { 133 "SRTP_AES128_CM_SHA1_32", 134 SRTP_AES128_CM_SHA1_32, 135 }, 136 {0} 137 }; 138 139 static int 140 find_profile_by_name(char *profile_name, SRTP_PROTECTION_PROFILE **pptr, 141 unsigned len) 142 { 143 SRTP_PROTECTION_PROFILE *p; 144 145 p = srtp_known_profiles; 146 while (p->name) { 147 if ((len == strlen(p->name)) && 148 !strncmp(p->name, profile_name, len)) { 149 *pptr = p; 150 return 0; 151 } 152 153 p++; 154 } 155 156 return 1; 157 } 158 159 static int 160 find_profile_by_num(unsigned profile_num, SRTP_PROTECTION_PROFILE **pptr) 161 { 162 SRTP_PROTECTION_PROFILE *p; 163 164 p = srtp_known_profiles; 165 while (p->name) { 166 if (p->id == profile_num) { 167 *pptr = p; 168 return 0; 169 } 170 p++; 171 } 172 173 return 1; 174 } 175 176 static int 177 ssl_ctx_make_profiles(const char *profiles_string, 178 STACK_OF(SRTP_PROTECTION_PROFILE) **out) 179 { 180 STACK_OF(SRTP_PROTECTION_PROFILE) *profiles; 181 182 char *col; 183 char *ptr = (char *)profiles_string; 184 185 SRTP_PROTECTION_PROFILE *p; 186 187 if (!(profiles = sk_SRTP_PROTECTION_PROFILE_new_null())) { 188 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES, 189 SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES); 190 return 1; 191 } 192 193 do { 194 col = strchr(ptr, ':'); 195 196 if (!find_profile_by_name(ptr, &p, 197 col ? col - ptr : (int)strlen(ptr))) { 198 sk_SRTP_PROTECTION_PROFILE_push(profiles, p); 199 } else { 200 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES, 201 SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE); 202 sk_SRTP_PROTECTION_PROFILE_free(profiles); 203 return 1; 204 } 205 206 if (col) 207 ptr = col + 1; 208 } while (col); 209 210 *out = profiles; 211 212 return 0; 213 } 214 215 int 216 SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx, const char *profiles) 217 { 218 return ssl_ctx_make_profiles(profiles, &ctx->srtp_profiles); 219 } 220 221 int 222 SSL_set_tlsext_use_srtp(SSL *s, const char *profiles) 223 { 224 return ssl_ctx_make_profiles(profiles, &s->srtp_profiles); 225 } 226 227 228 STACK_OF(SRTP_PROTECTION_PROFILE) * 229 SSL_get_srtp_profiles(SSL *s) 230 { 231 if (s != NULL) { 232 if (s->srtp_profiles != NULL) { 233 return s->srtp_profiles; 234 } else if ((s->ctx != NULL) && 235 (s->ctx->srtp_profiles != NULL)) { 236 return s->ctx->srtp_profiles; 237 } 238 } 239 240 return NULL; 241 } 242 243 SRTP_PROTECTION_PROFILE * 244 SSL_get_selected_srtp_profile(SSL *s) 245 { 246 return s->srtp_profile; 247 } 248 249 /* Note: this function returns 0 length if there are no 250 profiles specified */ 251 int 252 ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len, int maxlen) 253 { 254 int ct = 0; 255 int i; 256 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0; 257 SRTP_PROTECTION_PROFILE *prof; 258 259 clnt = SSL_get_srtp_profiles(s); 260 261 ct = sk_SRTP_PROTECTION_PROFILE_num(clnt); /* -1 if clnt == 0 */ 262 263 if (p) { 264 if (ct == 0) { 265 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT, 266 SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST); 267 return 1; 268 } 269 270 if ((2 + ct * 2 + 1) > maxlen) { 271 SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT, 272 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG); 273 return 1; 274 } 275 276 /* Add the length */ 277 s2n(ct * 2, p); 278 for (i = 0; i < ct; i++) { 279 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i); 280 s2n(prof->id, p); 281 } 282 283 /* Add an empty use_mki value */ 284 *p++ = 0; 285 } 286 287 *len = 2 + ct*2 + 1; 288 289 return 0; 290 } 291 292 293 int 294 ssl_parse_clienthello_use_srtp_ext(SSL *s, unsigned char *d, int len, int *al) 295 { 296 SRTP_PROTECTION_PROFILE *cprof, *sprof; 297 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0, *srvr; 298 int ct; 299 int mki_len; 300 int i, j; 301 int id; 302 int ret = 1; 303 304 /* Length value + the MKI length */ 305 if (len < 3) { 306 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT, 307 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 308 *al = SSL_AD_DECODE_ERROR; 309 goto done; 310 } 311 312 /* Pull off the length of the cipher suite list */ 313 n2s(d, ct); 314 len -= 2; 315 316 /* Check that it is even */ 317 if (ct % 2) { 318 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT, 319 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 320 *al = SSL_AD_DECODE_ERROR; 321 goto done; 322 } 323 324 /* Check that lengths are consistent */ 325 if (len < (ct + 1)) { 326 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT, 327 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 328 *al = SSL_AD_DECODE_ERROR; 329 goto done; 330 } 331 332 333 clnt = sk_SRTP_PROTECTION_PROFILE_new_null(); 334 335 while (ct) { 336 n2s(d, id); 337 ct -= 2; 338 len -= 2; 339 340 if (!find_profile_by_num(id, &cprof)) { 341 sk_SRTP_PROTECTION_PROFILE_push(clnt, cprof); 342 } else { 343 ; /* Ignore */ 344 } 345 } 346 347 /* Extract the MKI value as a sanity check, but discard it for now. */ 348 mki_len = *d; 349 d++; 350 len--; 351 352 if (mki_len != len) { 353 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT, 354 SSL_R_BAD_SRTP_MKI_VALUE); 355 *al = SSL_AD_DECODE_ERROR; 356 sk_SRTP_PROTECTION_PROFILE_free(clnt); 357 goto done; 358 } 359 360 srvr = SSL_get_srtp_profiles(s); 361 362 /* 363 * Pick our most preferred profile. If no profiles have been 364 * configured then the outer loop doesn't run 365 * (sk_SRTP_PROTECTION_PROFILE_num() = -1) 366 * and so we just return without doing anything. 367 */ 368 for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(srvr); i++) { 369 sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i); 370 371 for (j = 0; j < sk_SRTP_PROTECTION_PROFILE_num(clnt); j++) { 372 cprof = sk_SRTP_PROTECTION_PROFILE_value(clnt, j); 373 374 if (cprof->id == sprof->id) { 375 s->srtp_profile = sprof; 376 *al = 0; 377 ret = 0; 378 goto done; 379 } 380 } 381 } 382 383 ret = 0; 384 385 done: 386 if (clnt) 387 sk_SRTP_PROTECTION_PROFILE_free(clnt); 388 389 return ret; 390 } 391 392 int 393 ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len, int maxlen) 394 { 395 if (p) { 396 if (maxlen < 5) { 397 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT, 398 SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG); 399 return 1; 400 } 401 402 if (s->srtp_profile == 0) { 403 SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT, 404 SSL_R_USE_SRTP_NOT_NEGOTIATED); 405 return 1; 406 } 407 s2n(2, p); 408 s2n(s->srtp_profile->id, p); 409 *p++ = 0; 410 } 411 *len = 5; 412 413 return 0; 414 } 415 416 417 int 418 ssl_parse_serverhello_use_srtp_ext(SSL *s, unsigned char *d, int len, int *al) 419 { 420 STACK_OF(SRTP_PROTECTION_PROFILE) *clnt; 421 SRTP_PROTECTION_PROFILE *prof; 422 unsigned id; 423 int i; 424 int ct; 425 426 if (len != 5) { 427 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 428 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 429 *al = SSL_AD_DECODE_ERROR; 430 return 1; 431 } 432 433 n2s(d, ct); 434 if (ct != 2) { 435 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 436 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 437 *al = SSL_AD_DECODE_ERROR; 438 return 1; 439 } 440 441 n2s(d, id); 442 if (*d) { 443 /* Must be no MKI, since we never offer one. */ 444 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 445 SSL_R_BAD_SRTP_MKI_VALUE); 446 *al = SSL_AD_ILLEGAL_PARAMETER; 447 return 1; 448 } 449 450 clnt = SSL_get_srtp_profiles(s); 451 452 /* Throw an error if the server gave us an unsolicited extension. */ 453 if (clnt == NULL) { 454 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 455 SSL_R_NO_SRTP_PROFILES); 456 *al = SSL_AD_DECODE_ERROR; 457 return 1; 458 } 459 460 /* 461 * Check to see if the server gave us something we support 462 * (and presumably offered). 463 */ 464 for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) { 465 prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i); 466 467 if (prof->id == id) { 468 s->srtp_profile = prof; 469 *al = 0; 470 return 0; 471 } 472 } 473 474 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT, 475 SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); 476 *al = SSL_AD_DECODE_ERROR; 477 return 1; 478 } 479 480 #endif 481