1 /* $OpenBSD: t1_lib.c,v 1.165 2020/03/10 17:02:21 jsing 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) 1998-2007 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 #include <stdio.h> 113 114 #include <openssl/evp.h> 115 #include <openssl/hmac.h> 116 #include <openssl/objects.h> 117 #include <openssl/ocsp.h> 118 119 #include "ssl_locl.h" 120 121 #include "bytestring.h" 122 #include "ssl_sigalgs.h" 123 #include "ssl_tlsext.h" 124 125 static int tls_decrypt_ticket(SSL *s, CBS *session_id, CBS *ticket, 126 SSL_SESSION **psess); 127 128 SSL3_ENC_METHOD TLSv1_enc_data = { 129 .enc_flags = 0, 130 }; 131 132 SSL3_ENC_METHOD TLSv1_1_enc_data = { 133 .enc_flags = SSL_ENC_FLAG_EXPLICIT_IV, 134 }; 135 136 SSL3_ENC_METHOD TLSv1_2_enc_data = { 137 .enc_flags = SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS| 138 SSL_ENC_FLAG_SHA256_PRF|SSL_ENC_FLAG_TLS1_2_CIPHERS, 139 }; 140 141 long 142 tls1_default_timeout(void) 143 { 144 /* 2 hours, the 24 hours mentioned in the TLSv1 spec 145 * is way too long for http, the cache would over fill */ 146 return (60 * 60 * 2); 147 } 148 149 int 150 tls1_new(SSL *s) 151 { 152 if (!ssl3_new(s)) 153 return (0); 154 s->method->internal->ssl_clear(s); 155 return (1); 156 } 157 158 void 159 tls1_free(SSL *s) 160 { 161 if (s == NULL) 162 return; 163 164 free(s->internal->tlsext_session_ticket); 165 ssl3_free(s); 166 } 167 168 void 169 tls1_clear(SSL *s) 170 { 171 ssl3_clear(s); 172 s->version = s->method->internal->version; 173 } 174 175 static int nid_list[] = { 176 NID_sect163k1, /* sect163k1 (1) */ 177 NID_sect163r1, /* sect163r1 (2) */ 178 NID_sect163r2, /* sect163r2 (3) */ 179 NID_sect193r1, /* sect193r1 (4) */ 180 NID_sect193r2, /* sect193r2 (5) */ 181 NID_sect233k1, /* sect233k1 (6) */ 182 NID_sect233r1, /* sect233r1 (7) */ 183 NID_sect239k1, /* sect239k1 (8) */ 184 NID_sect283k1, /* sect283k1 (9) */ 185 NID_sect283r1, /* sect283r1 (10) */ 186 NID_sect409k1, /* sect409k1 (11) */ 187 NID_sect409r1, /* sect409r1 (12) */ 188 NID_sect571k1, /* sect571k1 (13) */ 189 NID_sect571r1, /* sect571r1 (14) */ 190 NID_secp160k1, /* secp160k1 (15) */ 191 NID_secp160r1, /* secp160r1 (16) */ 192 NID_secp160r2, /* secp160r2 (17) */ 193 NID_secp192k1, /* secp192k1 (18) */ 194 NID_X9_62_prime192v1, /* secp192r1 (19) */ 195 NID_secp224k1, /* secp224k1 (20) */ 196 NID_secp224r1, /* secp224r1 (21) */ 197 NID_secp256k1, /* secp256k1 (22) */ 198 NID_X9_62_prime256v1, /* secp256r1 (23) */ 199 NID_secp384r1, /* secp384r1 (24) */ 200 NID_secp521r1, /* secp521r1 (25) */ 201 NID_brainpoolP256r1, /* brainpoolP256r1 (26) */ 202 NID_brainpoolP384r1, /* brainpoolP384r1 (27) */ 203 NID_brainpoolP512r1, /* brainpoolP512r1 (28) */ 204 NID_X25519, /* X25519 (29) */ 205 }; 206 207 #if 0 208 static const uint8_t ecformats_list[] = { 209 TLSEXT_ECPOINTFORMAT_uncompressed, 210 TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime, 211 TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2 212 }; 213 #endif 214 215 static const uint8_t ecformats_default[] = { 216 TLSEXT_ECPOINTFORMAT_uncompressed, 217 }; 218 219 #if 0 220 static const uint16_t eccurves_list[] = { 221 29, /* X25519 (29) */ 222 14, /* sect571r1 (14) */ 223 13, /* sect571k1 (13) */ 224 25, /* secp521r1 (25) */ 225 28, /* brainpoolP512r1 (28) */ 226 11, /* sect409k1 (11) */ 227 12, /* sect409r1 (12) */ 228 27, /* brainpoolP384r1 (27) */ 229 24, /* secp384r1 (24) */ 230 9, /* sect283k1 (9) */ 231 10, /* sect283r1 (10) */ 232 26, /* brainpoolP256r1 (26) */ 233 22, /* secp256k1 (22) */ 234 23, /* secp256r1 (23) */ 235 8, /* sect239k1 (8) */ 236 6, /* sect233k1 (6) */ 237 7, /* sect233r1 (7) */ 238 20, /* secp224k1 (20) */ 239 21, /* secp224r1 (21) */ 240 4, /* sect193r1 (4) */ 241 5, /* sect193r2 (5) */ 242 18, /* secp192k1 (18) */ 243 19, /* secp192r1 (19) */ 244 1, /* sect163k1 (1) */ 245 2, /* sect163r1 (2) */ 246 3, /* sect163r2 (3) */ 247 15, /* secp160k1 (15) */ 248 16, /* secp160r1 (16) */ 249 17, /* secp160r2 (17) */ 250 }; 251 #endif 252 253 static const uint16_t eccurves_default[] = { 254 29, /* X25519 (29) */ 255 23, /* secp256r1 (23) */ 256 24, /* secp384r1 (24) */ 257 }; 258 259 int 260 tls1_ec_curve_id2nid(const uint16_t curve_id) 261 { 262 /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */ 263 if ((curve_id < 1) || 264 ((unsigned int)curve_id > sizeof(nid_list) / sizeof(nid_list[0]))) 265 return 0; 266 return nid_list[curve_id - 1]; 267 } 268 269 uint16_t 270 tls1_ec_nid2curve_id(const int nid) 271 { 272 /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */ 273 switch (nid) { 274 case NID_sect163k1: /* sect163k1 (1) */ 275 return 1; 276 case NID_sect163r1: /* sect163r1 (2) */ 277 return 2; 278 case NID_sect163r2: /* sect163r2 (3) */ 279 return 3; 280 case NID_sect193r1: /* sect193r1 (4) */ 281 return 4; 282 case NID_sect193r2: /* sect193r2 (5) */ 283 return 5; 284 case NID_sect233k1: /* sect233k1 (6) */ 285 return 6; 286 case NID_sect233r1: /* sect233r1 (7) */ 287 return 7; 288 case NID_sect239k1: /* sect239k1 (8) */ 289 return 8; 290 case NID_sect283k1: /* sect283k1 (9) */ 291 return 9; 292 case NID_sect283r1: /* sect283r1 (10) */ 293 return 10; 294 case NID_sect409k1: /* sect409k1 (11) */ 295 return 11; 296 case NID_sect409r1: /* sect409r1 (12) */ 297 return 12; 298 case NID_sect571k1: /* sect571k1 (13) */ 299 return 13; 300 case NID_sect571r1: /* sect571r1 (14) */ 301 return 14; 302 case NID_secp160k1: /* secp160k1 (15) */ 303 return 15; 304 case NID_secp160r1: /* secp160r1 (16) */ 305 return 16; 306 case NID_secp160r2: /* secp160r2 (17) */ 307 return 17; 308 case NID_secp192k1: /* secp192k1 (18) */ 309 return 18; 310 case NID_X9_62_prime192v1: /* secp192r1 (19) */ 311 return 19; 312 case NID_secp224k1: /* secp224k1 (20) */ 313 return 20; 314 case NID_secp224r1: /* secp224r1 (21) */ 315 return 21; 316 case NID_secp256k1: /* secp256k1 (22) */ 317 return 22; 318 case NID_X9_62_prime256v1: /* secp256r1 (23) */ 319 return 23; 320 case NID_secp384r1: /* secp384r1 (24) */ 321 return 24; 322 case NID_secp521r1: /* secp521r1 (25) */ 323 return 25; 324 case NID_brainpoolP256r1: /* brainpoolP256r1 (26) */ 325 return 26; 326 case NID_brainpoolP384r1: /* brainpoolP384r1 (27) */ 327 return 27; 328 case NID_brainpoolP512r1: /* brainpoolP512r1 (28) */ 329 return 28; 330 case NID_X25519: /* X25519 (29) */ 331 return 29; 332 default: 333 return 0; 334 } 335 } 336 337 /* 338 * Return the appropriate format list. If client_formats is non-zero, return 339 * the client/session formats. Otherwise return the custom format list if one 340 * exists, or the default formats if a custom list has not been specified. 341 */ 342 void 343 tls1_get_formatlist(SSL *s, int client_formats, const uint8_t **pformats, 344 size_t *pformatslen) 345 { 346 if (client_formats != 0) { 347 *pformats = SSI(s)->tlsext_ecpointformatlist; 348 *pformatslen = SSI(s)->tlsext_ecpointformatlist_length; 349 return; 350 } 351 352 *pformats = s->internal->tlsext_ecpointformatlist; 353 *pformatslen = s->internal->tlsext_ecpointformatlist_length; 354 if (*pformats == NULL) { 355 *pformats = ecformats_default; 356 *pformatslen = sizeof(ecformats_default); 357 } 358 } 359 360 /* 361 * Return the appropriate group list. If client_groups is non-zero, return 362 * the client/session groups. Otherwise return the custom group list if one 363 * exists, or the default groups if a custom list has not been specified. 364 */ 365 void 366 tls1_get_group_list(SSL *s, int client_groups, const uint16_t **pgroups, 367 size_t *pgroupslen) 368 { 369 if (client_groups != 0) { 370 *pgroups = SSI(s)->tlsext_supportedgroups; 371 *pgroupslen = SSI(s)->tlsext_supportedgroups_length; 372 return; 373 } 374 375 *pgroups = s->internal->tlsext_supportedgroups; 376 *pgroupslen = s->internal->tlsext_supportedgroups_length; 377 if (*pgroups == NULL) { 378 *pgroups = eccurves_default; 379 *pgroupslen = sizeof(eccurves_default) / 2; 380 } 381 } 382 383 int 384 tls1_set_groups(uint16_t **out_group_ids, size_t *out_group_ids_len, 385 const int *groups, size_t ngroups) 386 { 387 uint16_t *group_ids; 388 size_t i; 389 390 group_ids = calloc(ngroups, sizeof(uint16_t)); 391 if (group_ids == NULL) 392 return 0; 393 394 for (i = 0; i < ngroups; i++) { 395 group_ids[i] = tls1_ec_nid2curve_id(groups[i]); 396 if (group_ids[i] == 0) { 397 free(group_ids); 398 return 0; 399 } 400 } 401 402 free(*out_group_ids); 403 *out_group_ids = group_ids; 404 *out_group_ids_len = ngroups; 405 406 return 1; 407 } 408 409 int 410 tls1_set_group_list(uint16_t **out_group_ids, size_t *out_group_ids_len, 411 const char *groups) 412 { 413 uint16_t *new_group_ids, *group_ids = NULL; 414 size_t ngroups = 0; 415 char *gs, *p, *q; 416 int nid; 417 418 if ((gs = strdup(groups)) == NULL) 419 return 0; 420 421 q = gs; 422 while ((p = strsep(&q, ":")) != NULL) { 423 nid = OBJ_sn2nid(p); 424 if (nid == NID_undef) 425 nid = OBJ_ln2nid(p); 426 if (nid == NID_undef) 427 nid = EC_curve_nist2nid(p); 428 if (nid == NID_undef) 429 goto err; 430 431 if ((new_group_ids = reallocarray(group_ids, ngroups + 1, 432 sizeof(uint16_t))) == NULL) 433 goto err; 434 group_ids = new_group_ids; 435 436 group_ids[ngroups] = tls1_ec_nid2curve_id(nid); 437 if (group_ids[ngroups] == 0) 438 goto err; 439 440 ngroups++; 441 } 442 443 free(gs); 444 free(*out_group_ids); 445 *out_group_ids = group_ids; 446 *out_group_ids_len = ngroups; 447 448 return 1; 449 450 err: 451 free(gs); 452 free(group_ids); 453 454 return 0; 455 } 456 457 /* Check that a curve is one of our preferences. */ 458 int 459 tls1_check_curve(SSL *s, const uint16_t curve_id) 460 { 461 const uint16_t *groups; 462 size_t groupslen, i; 463 464 tls1_get_group_list(s, 0, &groups, &groupslen); 465 466 for (i = 0; i < groupslen; i++) { 467 if (groups[i] == curve_id) 468 return (1); 469 } 470 return (0); 471 } 472 473 int 474 tls1_get_shared_curve(SSL *s) 475 { 476 size_t preflen, supplen, i, j; 477 const uint16_t *pref, *supp; 478 unsigned long server_pref; 479 480 /* Cannot do anything on the client side. */ 481 if (s->server == 0) 482 return (NID_undef); 483 484 /* Return first preference shared curve. */ 485 server_pref = (s->internal->options & SSL_OP_CIPHER_SERVER_PREFERENCE); 486 tls1_get_group_list(s, (server_pref == 0), &pref, &preflen); 487 tls1_get_group_list(s, (server_pref != 0), &supp, &supplen); 488 489 for (i = 0; i < preflen; i++) { 490 for (j = 0; j < supplen; j++) { 491 if (pref[i] == supp[j]) 492 return (tls1_ec_curve_id2nid(pref[i])); 493 } 494 } 495 return (NID_undef); 496 } 497 498 /* For an EC key set TLS ID and required compression based on parameters. */ 499 static int 500 tls1_set_ec_id(uint16_t *curve_id, uint8_t *comp_id, EC_KEY *ec) 501 { 502 const EC_GROUP *grp; 503 const EC_METHOD *meth; 504 int is_prime = 0; 505 int nid, id; 506 507 if (ec == NULL) 508 return (0); 509 510 /* Determine if it is a prime field. */ 511 if ((grp = EC_KEY_get0_group(ec)) == NULL) 512 return (0); 513 if ((meth = EC_GROUP_method_of(grp)) == NULL) 514 return (0); 515 if (EC_METHOD_get_field_type(meth) == NID_X9_62_prime_field) 516 is_prime = 1; 517 518 /* Determine curve ID. */ 519 nid = EC_GROUP_get_curve_name(grp); 520 id = tls1_ec_nid2curve_id(nid); 521 522 /* If we have an ID set it, otherwise set arbitrary explicit curve. */ 523 if (id != 0) 524 *curve_id = id; 525 else 526 *curve_id = is_prime ? 0xff01 : 0xff02; 527 528 /* Specify the compression identifier. */ 529 if (comp_id != NULL) { 530 if (EC_KEY_get0_public_key(ec) == NULL) 531 return (0); 532 533 if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED) { 534 *comp_id = is_prime ? 535 TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime : 536 TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2; 537 } else { 538 *comp_id = TLSEXT_ECPOINTFORMAT_uncompressed; 539 } 540 } 541 return (1); 542 } 543 544 /* Check that an EC key is compatible with extensions. */ 545 static int 546 tls1_check_ec_key(SSL *s, const uint16_t *curve_id, const uint8_t *comp_id) 547 { 548 size_t groupslen, formatslen, i; 549 const uint16_t *groups; 550 const uint8_t *formats; 551 552 /* 553 * Check point formats extension if present, otherwise everything 554 * is supported (see RFC4492). 555 */ 556 tls1_get_formatlist(s, 1, &formats, &formatslen); 557 if (comp_id != NULL && formats != NULL) { 558 for (i = 0; i < formatslen; i++) { 559 if (formats[i] == *comp_id) 560 break; 561 } 562 if (i == formatslen) 563 return (0); 564 } 565 566 /* 567 * Check curve list if present, otherwise everything is supported. 568 */ 569 tls1_get_group_list(s, 1, &groups, &groupslen); 570 if (curve_id != NULL && groups != NULL) { 571 for (i = 0; i < groupslen; i++) { 572 if (groups[i] == *curve_id) 573 break; 574 } 575 if (i == groupslen) 576 return (0); 577 } 578 579 return (1); 580 } 581 582 /* Check EC server key is compatible with client extensions. */ 583 int 584 tls1_check_ec_server_key(SSL *s) 585 { 586 CERT_PKEY *cpk = s->cert->pkeys + SSL_PKEY_ECC; 587 uint16_t curve_id; 588 uint8_t comp_id; 589 EVP_PKEY *pkey; 590 int rv; 591 592 if (cpk->x509 == NULL || cpk->privatekey == NULL) 593 return (0); 594 if ((pkey = X509_get_pubkey(cpk->x509)) == NULL) 595 return (0); 596 rv = tls1_set_ec_id(&curve_id, &comp_id, pkey->pkey.ec); 597 EVP_PKEY_free(pkey); 598 if (rv != 1) 599 return (0); 600 601 return tls1_check_ec_key(s, &curve_id, &comp_id); 602 } 603 604 int 605 ssl_check_clienthello_tlsext_early(SSL *s) 606 { 607 int ret = SSL_TLSEXT_ERR_NOACK; 608 int al = SSL_AD_UNRECOGNIZED_NAME; 609 610 /* The handling of the ECPointFormats extension is done elsewhere, namely in 611 * ssl3_choose_cipher in s3_lib.c. 612 */ 613 /* The handling of the EllipticCurves extension is done elsewhere, namely in 614 * ssl3_choose_cipher in s3_lib.c. 615 */ 616 617 if (s->ctx != NULL && s->ctx->internal->tlsext_servername_callback != 0) 618 ret = s->ctx->internal->tlsext_servername_callback(s, &al, 619 s->ctx->internal->tlsext_servername_arg); 620 else if (s->initial_ctx != NULL && s->initial_ctx->internal->tlsext_servername_callback != 0) 621 ret = s->initial_ctx->internal->tlsext_servername_callback(s, &al, 622 s->initial_ctx->internal->tlsext_servername_arg); 623 624 switch (ret) { 625 case SSL_TLSEXT_ERR_ALERT_FATAL: 626 ssl3_send_alert(s, SSL3_AL_FATAL, al); 627 return -1; 628 case SSL_TLSEXT_ERR_ALERT_WARNING: 629 ssl3_send_alert(s, SSL3_AL_WARNING, al); 630 return 1; 631 case SSL_TLSEXT_ERR_NOACK: 632 s->internal->servername_done = 0; 633 default: 634 return 1; 635 } 636 } 637 638 int 639 ssl_check_clienthello_tlsext_late(SSL *s) 640 { 641 int ret = SSL_TLSEXT_ERR_OK; 642 int al = 0; /* XXX gcc3 */ 643 644 /* If status request then ask callback what to do. 645 * Note: this must be called after servername callbacks in case 646 * the certificate has changed, and must be called after the cipher 647 * has been chosen because this may influence which certificate is sent 648 */ 649 if ((s->tlsext_status_type != -1) && 650 s->ctx && s->ctx->internal->tlsext_status_cb) { 651 int r; 652 CERT_PKEY *certpkey; 653 certpkey = ssl_get_server_send_pkey(s); 654 /* If no certificate can't return certificate status */ 655 if (certpkey == NULL) { 656 s->internal->tlsext_status_expected = 0; 657 return 1; 658 } 659 /* Set current certificate to one we will use so 660 * SSL_get_certificate et al can pick it up. 661 */ 662 s->cert->key = certpkey; 663 r = s->ctx->internal->tlsext_status_cb(s, 664 s->ctx->internal->tlsext_status_arg); 665 switch (r) { 666 /* We don't want to send a status request response */ 667 case SSL_TLSEXT_ERR_NOACK: 668 s->internal->tlsext_status_expected = 0; 669 break; 670 /* status request response should be sent */ 671 case SSL_TLSEXT_ERR_OK: 672 if (s->internal->tlsext_ocsp_resp) 673 s->internal->tlsext_status_expected = 1; 674 else 675 s->internal->tlsext_status_expected = 0; 676 break; 677 /* something bad happened */ 678 case SSL_TLSEXT_ERR_ALERT_FATAL: 679 ret = SSL_TLSEXT_ERR_ALERT_FATAL; 680 al = SSL_AD_INTERNAL_ERROR; 681 goto err; 682 } 683 } else 684 s->internal->tlsext_status_expected = 0; 685 686 err: 687 switch (ret) { 688 case SSL_TLSEXT_ERR_ALERT_FATAL: 689 ssl3_send_alert(s, SSL3_AL_FATAL, al); 690 return -1; 691 case SSL_TLSEXT_ERR_ALERT_WARNING: 692 ssl3_send_alert(s, SSL3_AL_WARNING, al); 693 return 1; 694 default: 695 return 1; 696 } 697 } 698 699 int 700 ssl_check_serverhello_tlsext(SSL *s) 701 { 702 int ret = SSL_TLSEXT_ERR_NOACK; 703 int al = SSL_AD_UNRECOGNIZED_NAME; 704 705 ret = SSL_TLSEXT_ERR_OK; 706 707 if (s->ctx != NULL && s->ctx->internal->tlsext_servername_callback != 0) 708 ret = s->ctx->internal->tlsext_servername_callback(s, &al, 709 s->ctx->internal->tlsext_servername_arg); 710 else if (s->initial_ctx != NULL && s->initial_ctx->internal->tlsext_servername_callback != 0) 711 ret = s->initial_ctx->internal->tlsext_servername_callback(s, &al, 712 s->initial_ctx->internal->tlsext_servername_arg); 713 714 /* If we've requested certificate status and we wont get one 715 * tell the callback 716 */ 717 if ((s->tlsext_status_type != -1) && !(s->internal->tlsext_status_expected) && 718 s->ctx && s->ctx->internal->tlsext_status_cb) { 719 int r; 720 /* Set resp to NULL, resplen to -1 so callback knows 721 * there is no response. 722 */ 723 free(s->internal->tlsext_ocsp_resp); 724 s->internal->tlsext_ocsp_resp = NULL; 725 s->internal->tlsext_ocsp_resplen = -1; 726 r = s->ctx->internal->tlsext_status_cb(s, 727 s->ctx->internal->tlsext_status_arg); 728 if (r == 0) { 729 al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE; 730 ret = SSL_TLSEXT_ERR_ALERT_FATAL; 731 } 732 if (r < 0) { 733 al = SSL_AD_INTERNAL_ERROR; 734 ret = SSL_TLSEXT_ERR_ALERT_FATAL; 735 } 736 } 737 738 switch (ret) { 739 case SSL_TLSEXT_ERR_ALERT_FATAL: 740 ssl3_send_alert(s, SSL3_AL_FATAL, al); 741 742 return -1; 743 case SSL_TLSEXT_ERR_ALERT_WARNING: 744 ssl3_send_alert(s, SSL3_AL_WARNING, al); 745 746 return 1; 747 case SSL_TLSEXT_ERR_NOACK: 748 s->internal->servername_done = 0; 749 default: 750 return 1; 751 } 752 } 753 754 /* Since the server cache lookup is done early on in the processing of the 755 * ClientHello, and other operations depend on the result, we need to handle 756 * any TLS session ticket extension at the same time. 757 * 758 * session_id: a CBS containing the session ID. 759 * ext_block: a CBS for the ClientHello extensions block. 760 * ret: (output) on return, if a ticket was decrypted, then this is set to 761 * point to the resulting session. 762 * 763 * If s->internal->tls_session_secret_cb is set then we are expecting a pre-shared key 764 * ciphersuite, in which case we have no use for session tickets and one will 765 * never be decrypted, nor will s->internal->tlsext_ticket_expected be set to 1. 766 * 767 * Returns: 768 * -1: fatal error, either from parsing or decrypting the ticket. 769 * 0: no ticket was found (or was ignored, based on settings). 770 * 1: a zero length extension was found, indicating that the client supports 771 * session tickets but doesn't currently have one to offer. 772 * 2: either s->internal->tls_session_secret_cb was set, or a ticket was offered but 773 * couldn't be decrypted because of a non-fatal error. 774 * 3: a ticket was successfully decrypted and *ret was set. 775 * 776 * Side effects: 777 * Sets s->internal->tlsext_ticket_expected to 1 if the server will have to issue 778 * a new session ticket to the client because the client indicated support 779 * (and s->internal->tls_session_secret_cb is NULL) but the client either doesn't have 780 * a session ticket or we couldn't use the one it gave us, or if 781 * s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket. 782 * Otherwise, s->internal->tlsext_ticket_expected is set to 0. 783 */ 784 int 785 tls1_process_ticket(SSL *s, CBS *session_id, CBS *ext_block, SSL_SESSION **ret) 786 { 787 CBS extensions, ext_data; 788 uint16_t ext_type = 0; 789 int r; 790 791 s->internal->tlsext_ticket_expected = 0; 792 *ret = NULL; 793 794 /* 795 * If tickets disabled behave as if no ticket present to permit stateful 796 * resumption. 797 */ 798 if (SSL_get_options(s) & SSL_OP_NO_TICKET) 799 return 0; 800 801 /* 802 * An empty extensions block is valid, but obviously does not contain 803 * a session ticket. 804 */ 805 if (CBS_len(ext_block) == 0) 806 return 0; 807 808 if (!CBS_get_u16_length_prefixed(ext_block, &extensions)) 809 return -1; 810 811 while (CBS_len(&extensions) > 0) { 812 if (!CBS_get_u16(&extensions, &ext_type) || 813 !CBS_get_u16_length_prefixed(&extensions, &ext_data)) 814 return -1; 815 816 if (ext_type == TLSEXT_TYPE_session_ticket) 817 break; 818 } 819 820 if (ext_type != TLSEXT_TYPE_session_ticket) 821 return 0; 822 823 if (CBS_len(&ext_data) == 0) { 824 /* 825 * The client will accept a ticket but does not currently 826 * have one. 827 */ 828 s->internal->tlsext_ticket_expected = 1; 829 return 1; 830 } 831 832 if (s->internal->tls_session_secret_cb != NULL) { 833 /* 834 * Indicate that the ticket could not be decrypted rather than 835 * generating the session from ticket now, trigger abbreviated 836 * handshake based on external mechanism to calculate the master 837 * secret later. 838 */ 839 return 2; 840 } 841 842 r = tls_decrypt_ticket(s, session_id, &ext_data, ret); 843 switch (r) { 844 case 2: /* ticket couldn't be decrypted */ 845 s->internal->tlsext_ticket_expected = 1; 846 return 2; 847 case 3: /* ticket was decrypted */ 848 return r; 849 case 4: /* ticket decrypted but need to renew */ 850 s->internal->tlsext_ticket_expected = 1; 851 return 3; 852 default: /* fatal error */ 853 return -1; 854 } 855 } 856 857 /* tls_decrypt_ticket attempts to decrypt a session ticket. 858 * 859 * session_id: a CBS containing the session ID. 860 * ticket: a CBS containing the body of the session ticket extension. 861 * psess: (output) on return, if a ticket was decrypted, then this is set to 862 * point to the resulting session. 863 * 864 * Returns: 865 * -1: fatal error, either from parsing or decrypting the ticket. 866 * 2: the ticket couldn't be decrypted. 867 * 3: a ticket was successfully decrypted and *psess was set. 868 * 4: same as 3, but the ticket needs to be renewed. 869 */ 870 static int 871 tls_decrypt_ticket(SSL *s, CBS *session_id, CBS *ticket, SSL_SESSION **psess) 872 { 873 CBS ticket_name, ticket_iv, ticket_encdata, ticket_hmac; 874 SSL_SESSION *sess = NULL; 875 unsigned char *sdec = NULL; 876 size_t sdec_len = 0; 877 size_t session_id_len; 878 const unsigned char *p; 879 unsigned char hmac[EVP_MAX_MD_SIZE]; 880 HMAC_CTX *hctx = NULL; 881 EVP_CIPHER_CTX *cctx = NULL; 882 SSL_CTX *tctx = s->initial_ctx; 883 int slen, hlen; 884 int renew_ticket = 0; 885 int ret = -1; 886 887 *psess = NULL; 888 889 if (!CBS_get_bytes(ticket, &ticket_name, 16)) 890 goto derr; 891 892 /* 893 * Initialize session ticket encryption and HMAC contexts. 894 */ 895 if ((cctx = EVP_CIPHER_CTX_new()) == NULL) 896 goto err; 897 if ((hctx = HMAC_CTX_new()) == NULL) 898 goto err; 899 900 if (tctx->internal->tlsext_ticket_key_cb != NULL) { 901 int rv; 902 903 /* 904 * The API guarantees EVP_MAX_IV_LENGTH bytes of space for 905 * the iv to tlsext_ticket_key_cb(). Since the total space 906 * required for a session cookie is never less than this, 907 * this check isn't too strict. The exact check comes later. 908 */ 909 if (CBS_len(ticket) < EVP_MAX_IV_LENGTH) 910 goto derr; 911 912 if ((rv = tctx->internal->tlsext_ticket_key_cb(s, 913 (unsigned char *)CBS_data(&ticket_name), 914 (unsigned char *)CBS_data(ticket), cctx, hctx, 0)) < 0) 915 goto err; 916 if (rv == 0) 917 goto derr; 918 if (rv == 2) 919 renew_ticket = 1; 920 921 /* 922 * Now that the cipher context is initialised, we can extract 923 * the IV since its length is known. 924 */ 925 if (!CBS_get_bytes(ticket, &ticket_iv, 926 EVP_CIPHER_CTX_iv_length(cctx))) 927 goto derr; 928 } else { 929 /* Check that the key name matches. */ 930 if (!CBS_mem_equal(&ticket_name, 931 tctx->internal->tlsext_tick_key_name, 932 sizeof(tctx->internal->tlsext_tick_key_name))) 933 goto derr; 934 if (!CBS_get_bytes(ticket, &ticket_iv, 935 EVP_CIPHER_iv_length(EVP_aes_128_cbc()))) 936 goto derr; 937 if (!EVP_DecryptInit_ex(cctx, EVP_aes_128_cbc(), NULL, 938 tctx->internal->tlsext_tick_aes_key, CBS_data(&ticket_iv))) 939 goto err; 940 if (!HMAC_Init_ex(hctx, tctx->internal->tlsext_tick_hmac_key, 941 sizeof(tctx->internal->tlsext_tick_hmac_key), EVP_sha256(), 942 NULL)) 943 goto err; 944 } 945 946 /* 947 * Attempt to process session ticket. 948 */ 949 950 if ((hlen = HMAC_size(hctx)) < 0) 951 goto err; 952 953 if (hlen > CBS_len(ticket)) 954 goto derr; 955 if (!CBS_get_bytes(ticket, &ticket_encdata, CBS_len(ticket) - hlen)) 956 goto derr; 957 if (!CBS_get_bytes(ticket, &ticket_hmac, hlen)) 958 goto derr; 959 if (CBS_len(ticket) != 0) 960 goto err; 961 962 /* Check HMAC of encrypted ticket. */ 963 if (HMAC_Update(hctx, CBS_data(&ticket_name), 964 CBS_len(&ticket_name)) <= 0) 965 goto err; 966 if (HMAC_Update(hctx, CBS_data(&ticket_iv), 967 CBS_len(&ticket_iv)) <= 0) 968 goto err; 969 if (HMAC_Update(hctx, CBS_data(&ticket_encdata), 970 CBS_len(&ticket_encdata)) <= 0) 971 goto err; 972 if (HMAC_Final(hctx, hmac, &hlen) <= 0) 973 goto err; 974 975 if (!CBS_mem_equal(&ticket_hmac, hmac, hlen)) 976 goto derr; 977 978 /* Attempt to decrypt session data. */ 979 sdec_len = CBS_len(&ticket_encdata); 980 if ((sdec = calloc(1, sdec_len)) == NULL) 981 goto err; 982 if (EVP_DecryptUpdate(cctx, sdec, &slen, CBS_data(&ticket_encdata), 983 CBS_len(&ticket_encdata)) <= 0) 984 goto derr; 985 if (EVP_DecryptFinal_ex(cctx, sdec + slen, &hlen) <= 0) 986 goto derr; 987 988 slen += hlen; 989 990 /* 991 * For session parse failures, indicate that we need to send a new 992 * ticket. 993 */ 994 p = sdec; 995 if ((sess = d2i_SSL_SESSION(NULL, &p, slen)) == NULL) 996 goto derr; 997 998 /* 999 * The session ID, if non-empty, is used by some clients to detect that 1000 * the ticket has been accepted. So we copy it to the session structure. 1001 * If it is empty set length to zero as required by standard. 1002 */ 1003 if (!CBS_write_bytes(session_id, sess->session_id, 1004 sizeof(sess->session_id), &session_id_len)) 1005 goto err; 1006 sess->session_id_length = (unsigned int)session_id_len; 1007 1008 *psess = sess; 1009 sess = NULL; 1010 1011 if (renew_ticket) 1012 ret = 4; 1013 else 1014 ret = 3; 1015 1016 goto done; 1017 1018 derr: 1019 ret = 2; 1020 goto done; 1021 1022 err: 1023 ret = -1; 1024 goto done; 1025 1026 done: 1027 freezero(sdec, sdec_len); 1028 EVP_CIPHER_CTX_free(cctx); 1029 HMAC_CTX_free(hctx); 1030 SSL_SESSION_free(sess); 1031 1032 if (ret == 2) 1033 ERR_clear_error(); 1034 1035 return ret; 1036 } 1037