1/* $OpenBSD: t1_lib.c,v 1.198 2023/11/18 10:51:09 tb 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 "bytestring.h" 120#include "ssl_local.h" 121#include "ssl_sigalgs.h" 122#include "ssl_tlsext.h" 123 124static int tls_decrypt_ticket(SSL *s, CBS *ticket, int *alert, 125 SSL_SESSION **psess); 126 127int 128tls1_new(SSL *s) 129{ 130 if (!ssl3_new(s)) 131 return (0); 132 s->method->ssl_clear(s); 133 return (1); 134} 135 136void 137tls1_free(SSL *s) 138{ 139 if (s == NULL) 140 return; 141 142 free(s->tlsext_session_ticket); 143 ssl3_free(s); 144} 145 146void 147tls1_clear(SSL *s) 148{ 149 ssl3_clear(s); 150 s->version = s->method->version; 151} 152 153struct supported_group { 154 int nid; 155 int bits; 156}; 157 158/* 159 * Supported groups (formerly known as named curves) 160 * https://www.iana.org/assignments/tls-parameters/#tls-parameters-8 161 */ 162static const struct supported_group nid_list[] = { 163 [1] = { 164 .nid = NID_sect163k1, 165 .bits = 80, 166 }, 167 [2] = { 168 .nid = NID_sect163r1, 169 .bits = 80, 170 }, 171 [3] = { 172 .nid = NID_sect163r2, 173 .bits = 80, 174 }, 175 [4] = { 176 .nid = NID_sect193r1, 177 .bits = 80, 178 }, 179 [5] = { 180 .nid = NID_sect193r2, 181 .bits = 80, 182 }, 183 [6] = { 184 .nid = NID_sect233k1, 185 .bits = 112, 186 }, 187 [7] = { 188 .nid = NID_sect233r1, 189 .bits = 112, 190 }, 191 [8] = { 192 .nid = NID_sect239k1, 193 .bits = 112, 194 }, 195 [9] = { 196 .nid = NID_sect283k1, 197 .bits = 128, 198 }, 199 [10] = { 200 .nid = NID_sect283r1, 201 .bits = 128, 202 }, 203 [11] = { 204 .nid = NID_sect409k1, 205 .bits = 192, 206 }, 207 [12] = { 208 .nid = NID_sect409r1, 209 .bits = 192, 210 }, 211 [13] = { 212 .nid = NID_sect571k1, 213 .bits = 256, 214 }, 215 [14] = { 216 .nid = NID_sect571r1, 217 .bits = 256, 218 }, 219 [15] = { 220 .nid = NID_secp160k1, 221 .bits = 80, 222 }, 223 [16] = { 224 .nid = NID_secp160r1, 225 .bits = 80, 226 }, 227 [17] = { 228 .nid = NID_secp160r2, 229 .bits = 80, 230 }, 231 [18] = { 232 .nid = NID_secp192k1, 233 .bits = 80, 234 }, 235 [19] = { 236 .nid = NID_X9_62_prime192v1, /* aka secp192r1 */ 237 .bits = 80, 238 }, 239 [20] = { 240 .nid = NID_secp224k1, 241 .bits = 112, 242 }, 243 [21] = { 244 .nid = NID_secp224r1, 245 .bits = 112, 246 }, 247 [22] = { 248 .nid = NID_secp256k1, 249 .bits = 128, 250 }, 251 [23] = { 252 .nid = NID_X9_62_prime256v1, /* aka secp256r1 */ 253 .bits = 128, 254 }, 255 [24] = { 256 .nid = NID_secp384r1, 257 .bits = 192, 258 }, 259 [25] = { 260 .nid = NID_secp521r1, 261 .bits = 256, 262 }, 263 [26] = { 264 .nid = NID_brainpoolP256r1, 265 .bits = 128, 266 }, 267 [27] = { 268 .nid = NID_brainpoolP384r1, 269 .bits = 192, 270 }, 271 [28] = { 272 .nid = NID_brainpoolP512r1, 273 .bits = 256, 274 }, 275 [29] = { 276 .nid = NID_X25519, 277 .bits = 128, 278 }, 279}; 280 281#define NID_LIST_LEN (sizeof(nid_list) / sizeof(nid_list[0])) 282 283#if 0 284static const uint8_t ecformats_list[] = { 285 TLSEXT_ECPOINTFORMAT_uncompressed, 286 TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime, 287 TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2 288}; 289#endif 290 291static const uint8_t ecformats_default[] = { 292 TLSEXT_ECPOINTFORMAT_uncompressed, 293}; 294 295#if 0 296static const uint16_t ecgroups_list[] = { 297 29, /* X25519 (29) */ 298 14, /* sect571r1 (14) */ 299 13, /* sect571k1 (13) */ 300 25, /* secp521r1 (25) */ 301 28, /* brainpoolP512r1 (28) */ 302 11, /* sect409k1 (11) */ 303 12, /* sect409r1 (12) */ 304 27, /* brainpoolP384r1 (27) */ 305 24, /* secp384r1 (24) */ 306 9, /* sect283k1 (9) */ 307 10, /* sect283r1 (10) */ 308 26, /* brainpoolP256r1 (26) */ 309 22, /* secp256k1 (22) */ 310 23, /* secp256r1 (23) */ 311 8, /* sect239k1 (8) */ 312 6, /* sect233k1 (6) */ 313 7, /* sect233r1 (7) */ 314 20, /* secp224k1 (20) */ 315 21, /* secp224r1 (21) */ 316 4, /* sect193r1 (4) */ 317 5, /* sect193r2 (5) */ 318 18, /* secp192k1 (18) */ 319 19, /* secp192r1 (19) */ 320 1, /* sect163k1 (1) */ 321 2, /* sect163r1 (2) */ 322 3, /* sect163r2 (3) */ 323 15, /* secp160k1 (15) */ 324 16, /* secp160r1 (16) */ 325 17, /* secp160r2 (17) */ 326}; 327#endif 328 329static const uint16_t ecgroups_client_default[] = { 330 29, /* X25519 (29) */ 331 23, /* secp256r1 (23) */ 332 24, /* secp384r1 (24) */ 333 25, /* secp521r1 (25) */ 334}; 335 336static const uint16_t ecgroups_server_default[] = { 337 29, /* X25519 (29) */ 338 23, /* secp256r1 (23) */ 339 24, /* secp384r1 (24) */ 340}; 341 342int 343tls1_ec_group_id2nid(uint16_t group_id, int *out_nid) 344{ 345 int nid; 346 347 if (group_id >= NID_LIST_LEN) 348 return 0; 349 350 if ((nid = nid_list[group_id].nid) == 0) 351 return 0; 352 353 *out_nid = nid; 354 355 return 1; 356} 357 358int 359tls1_ec_group_id2bits(uint16_t group_id, int *out_bits) 360{ 361 int bits; 362 363 if (group_id >= NID_LIST_LEN) 364 return 0; 365 366 if ((bits = nid_list[group_id].bits) == 0) 367 return 0; 368 369 *out_bits = bits; 370 371 return 1; 372} 373 374int 375tls1_ec_nid2group_id(int nid, uint16_t *out_group_id) 376{ 377 uint16_t group_id; 378 379 if (nid == 0) 380 return 0; 381 382 for (group_id = 0; group_id < NID_LIST_LEN; group_id++) { 383 if (nid_list[group_id].nid == nid) { 384 *out_group_id = group_id; 385 return 1; 386 } 387 } 388 389 return 0; 390} 391 392/* 393 * Return the appropriate format list. If client_formats is non-zero, return 394 * the client/session formats. Otherwise return the custom format list if one 395 * exists, or the default formats if a custom list has not been specified. 396 */ 397void 398tls1_get_formatlist(const SSL *s, int client_formats, const uint8_t **pformats, 399 size_t *pformatslen) 400{ 401 if (client_formats != 0) { 402 *pformats = s->session->tlsext_ecpointformatlist; 403 *pformatslen = s->session->tlsext_ecpointformatlist_length; 404 return; 405 } 406 407 *pformats = s->tlsext_ecpointformatlist; 408 *pformatslen = s->tlsext_ecpointformatlist_length; 409 if (*pformats == NULL) { 410 *pformats = ecformats_default; 411 *pformatslen = sizeof(ecformats_default); 412 } 413} 414 415/* 416 * Return the appropriate group list. If client_groups is non-zero, return 417 * the client/session groups. Otherwise return the custom group list if one 418 * exists, or the default groups if a custom list has not been specified. 419 */ 420void 421tls1_get_group_list(const SSL *s, int client_groups, const uint16_t **pgroups, 422 size_t *pgroupslen) 423{ 424 if (client_groups != 0) { 425 *pgroups = s->session->tlsext_supportedgroups; 426 *pgroupslen = s->session->tlsext_supportedgroups_length; 427 return; 428 } 429 430 *pgroups = s->tlsext_supportedgroups; 431 *pgroupslen = s->tlsext_supportedgroups_length; 432 if (*pgroups != NULL) 433 return; 434 435 if (!s->server) { 436 *pgroups = ecgroups_client_default; 437 *pgroupslen = sizeof(ecgroups_client_default) / 2; 438 } else { 439 *pgroups = ecgroups_server_default; 440 *pgroupslen = sizeof(ecgroups_server_default) / 2; 441 } 442} 443 444static int 445tls1_get_group_lists(const SSL *ssl, const uint16_t **pref, size_t *preflen, 446 const uint16_t **supp, size_t *supplen) 447{ 448 unsigned long server_pref; 449 450 /* Cannot do anything on the client side. */ 451 if (!ssl->server) 452 return 0; 453 454 server_pref = (ssl->options & SSL_OP_CIPHER_SERVER_PREFERENCE); 455 tls1_get_group_list(ssl, (server_pref == 0), pref, preflen); 456 tls1_get_group_list(ssl, (server_pref != 0), supp, supplen); 457 458 return 1; 459} 460 461static int 462tls1_group_id_present(uint16_t group_id, const uint16_t *list, size_t list_len) 463{ 464 size_t i; 465 466 for (i = 0; i < list_len; i++) { 467 if (group_id == list[i]) 468 return 1; 469 } 470 471 return 0; 472} 473 474int 475tls1_count_shared_groups(const SSL *ssl, size_t *out_count) 476{ 477 size_t count, preflen, supplen, i; 478 const uint16_t *pref, *supp; 479 480 if (!tls1_get_group_lists(ssl, &pref, &preflen, &supp, &supplen)) 481 return 0; 482 483 count = 0; 484 for (i = 0; i < preflen; i++) { 485 if (!tls1_group_id_present(pref[i], supp, supplen)) 486 continue; 487 488 if (!ssl_security_shared_group(ssl, pref[i])) 489 continue; 490 491 count++; 492 } 493 494 *out_count = count; 495 496 return 1; 497} 498 499static int 500tls1_group_by_index(const SSL *ssl, size_t n, int *out_nid, 501 int (*ssl_security_fn)(const SSL *, uint16_t)) 502{ 503 size_t count, preflen, supplen, i; 504 const uint16_t *pref, *supp; 505 506 if (!tls1_get_group_lists(ssl, &pref, &preflen, &supp, &supplen)) 507 return 0; 508 509 count = 0; 510 for (i = 0; i < preflen; i++) { 511 if (!tls1_group_id_present(pref[i], supp, supplen)) 512 continue; 513 514 if (!ssl_security_fn(ssl, pref[i])) 515 continue; 516 517 if (count++ == n) 518 return tls1_ec_group_id2nid(pref[i], out_nid); 519 } 520 521 return 0; 522} 523 524int 525tls1_get_shared_group_by_index(const SSL *ssl, size_t index, int *out_nid) 526{ 527 return tls1_group_by_index(ssl, index, out_nid, 528 ssl_security_shared_group); 529} 530 531int 532tls1_get_supported_group(const SSL *ssl, int *out_nid) 533{ 534 return tls1_group_by_index(ssl, 0, out_nid, 535 ssl_security_supported_group); 536} 537 538int 539tls1_set_groups(uint16_t **out_group_ids, size_t *out_group_ids_len, 540 const int *groups, size_t ngroups) 541{ 542 uint16_t *group_ids; 543 size_t i; 544 545 if ((group_ids = calloc(ngroups, sizeof(uint16_t))) == NULL) 546 return 0; 547 548 for (i = 0; i < ngroups; i++) { 549 if (!tls1_ec_nid2group_id(groups[i], &group_ids[i])) { 550 free(group_ids); 551 return 0; 552 } 553 } 554 555 free(*out_group_ids); 556 *out_group_ids = group_ids; 557 *out_group_ids_len = ngroups; 558 559 return 1; 560} 561 562int 563tls1_set_group_list(uint16_t **out_group_ids, size_t *out_group_ids_len, 564 const char *groups) 565{ 566 uint16_t *new_group_ids, *group_ids = NULL; 567 size_t ngroups = 0; 568 char *gs, *p, *q; 569 int nid; 570 571 if ((gs = strdup(groups)) == NULL) 572 return 0; 573 574 q = gs; 575 while ((p = strsep(&q, ":")) != NULL) { 576 nid = OBJ_sn2nid(p); 577 if (nid == NID_undef) 578 nid = OBJ_ln2nid(p); 579 if (nid == NID_undef) 580 nid = EC_curve_nist2nid(p); 581 if (nid == NID_undef) 582 goto err; 583 584 if ((new_group_ids = reallocarray(group_ids, ngroups + 1, 585 sizeof(uint16_t))) == NULL) 586 goto err; 587 group_ids = new_group_ids; 588 589 if (!tls1_ec_nid2group_id(nid, &group_ids[ngroups])) 590 goto err; 591 592 ngroups++; 593 } 594 595 free(gs); 596 free(*out_group_ids); 597 *out_group_ids = group_ids; 598 *out_group_ids_len = ngroups; 599 600 return 1; 601 602 err: 603 free(gs); 604 free(group_ids); 605 606 return 0; 607} 608 609/* Check that a group is one of our preferences. */ 610int 611tls1_check_group(SSL *s, uint16_t group_id) 612{ 613 const uint16_t *groups; 614 size_t groupslen, i; 615 616 tls1_get_group_list(s, 0, &groups, &groupslen); 617 618 for (i = 0; i < groupslen; i++) { 619 if (!ssl_security_supported_group(s, groups[i])) 620 continue; 621 if (groups[i] == group_id) 622 return 1; 623 } 624 return 0; 625} 626 627/* For an EC key set TLS ID and required compression based on parameters. */ 628static int 629tls1_set_ec_id(uint16_t *group_id, uint8_t *comp_id, EC_KEY *ec) 630{ 631 const EC_GROUP *grp; 632 const EC_METHOD *meth; 633 int prime_field; 634 int nid; 635 636 if (ec == NULL) 637 return (0); 638 639 /* Determine whether the group is defined over a prime field. */ 640 if ((grp = EC_KEY_get0_group(ec)) == NULL) 641 return (0); 642 if ((meth = EC_GROUP_method_of(grp)) == NULL) 643 return (0); 644 prime_field = (EC_METHOD_get_field_type(meth) == NID_X9_62_prime_field); 645 646 /* Determine group ID. */ 647 nid = EC_GROUP_get_curve_name(grp); 648 /* If we have an ID set it, otherwise set arbitrary explicit group. */ 649 if (!tls1_ec_nid2group_id(nid, group_id)) 650 *group_id = prime_field ? 0xff01 : 0xff02; 651 652 if (comp_id == NULL) 653 return (1); 654 655 /* Specify the compression identifier. */ 656 if (EC_KEY_get0_public_key(ec) == NULL) 657 return (0); 658 *comp_id = TLSEXT_ECPOINTFORMAT_uncompressed; 659 if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED) { 660 *comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2; 661 if (prime_field) 662 *comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime; 663 } 664 665 return (1); 666} 667 668/* Check that an EC key is compatible with extensions. */ 669static int 670tls1_check_ec_key(SSL *s, const uint16_t *group_id, const uint8_t *comp_id) 671{ 672 size_t groupslen, formatslen, i; 673 const uint16_t *groups; 674 const uint8_t *formats; 675 676 /* 677 * Check point formats extension if present, otherwise everything 678 * is supported (see RFC4492). 679 */ 680 tls1_get_formatlist(s, 1, &formats, &formatslen); 681 if (comp_id != NULL && formats != NULL) { 682 for (i = 0; i < formatslen; i++) { 683 if (formats[i] == *comp_id) 684 break; 685 } 686 if (i == formatslen) 687 return (0); 688 } 689 690 /* 691 * Check group list if present, otherwise everything is supported. 692 */ 693 tls1_get_group_list(s, 1, &groups, &groupslen); 694 if (group_id != NULL && groups != NULL) { 695 for (i = 0; i < groupslen; i++) { 696 if (groups[i] == *group_id) 697 break; 698 } 699 if (i == groupslen) 700 return (0); 701 } 702 703 return (1); 704} 705 706/* Check EC server key is compatible with client extensions. */ 707int 708tls1_check_ec_server_key(SSL *s) 709{ 710 SSL_CERT_PKEY *cpk = s->cert->pkeys + SSL_PKEY_ECC; 711 uint16_t group_id; 712 uint8_t comp_id; 713 EC_KEY *eckey; 714 EVP_PKEY *pkey; 715 716 if (cpk->x509 == NULL || cpk->privatekey == NULL) 717 return (0); 718 if ((pkey = X509_get0_pubkey(cpk->x509)) == NULL) 719 return (0); 720 if ((eckey = EVP_PKEY_get0_EC_KEY(pkey)) == NULL) 721 return (0); 722 if (!tls1_set_ec_id(&group_id, &comp_id, eckey)) 723 return (0); 724 725 return tls1_check_ec_key(s, &group_id, &comp_id); 726} 727 728int 729ssl_check_clienthello_tlsext_early(SSL *s) 730{ 731 int ret = SSL_TLSEXT_ERR_NOACK; 732 int al = SSL_AD_UNRECOGNIZED_NAME; 733 734 /* The handling of the ECPointFormats extension is done elsewhere, namely in 735 * ssl3_choose_cipher in s3_lib.c. 736 */ 737 /* The handling of the EllipticCurves extension is done elsewhere, namely in 738 * ssl3_choose_cipher in s3_lib.c. 739 */ 740 741 if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 742 ret = s->ctx->tlsext_servername_callback(s, &al, 743 s->ctx->tlsext_servername_arg); 744 else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0) 745 ret = s->initial_ctx->tlsext_servername_callback(s, &al, 746 s->initial_ctx->tlsext_servername_arg); 747 748 switch (ret) { 749 case SSL_TLSEXT_ERR_ALERT_FATAL: 750 ssl3_send_alert(s, SSL3_AL_FATAL, al); 751 return -1; 752 case SSL_TLSEXT_ERR_ALERT_WARNING: 753 ssl3_send_alert(s, SSL3_AL_WARNING, al); 754 return 1; 755 case SSL_TLSEXT_ERR_NOACK: 756 default: 757 return 1; 758 } 759} 760 761int 762ssl_check_clienthello_tlsext_late(SSL *s) 763{ 764 int ret = SSL_TLSEXT_ERR_OK; 765 int al = 0; /* XXX gcc3 */ 766 767 /* If status request then ask callback what to do. 768 * Note: this must be called after servername callbacks in case 769 * the certificate has changed, and must be called after the cipher 770 * has been chosen because this may influence which certificate is sent 771 */ 772 if ((s->tlsext_status_type != -1) && 773 s->ctx && s->ctx->tlsext_status_cb) { 774 int r; 775 SSL_CERT_PKEY *certpkey; 776 certpkey = ssl_get_server_send_pkey(s); 777 /* If no certificate can't return certificate status */ 778 if (certpkey == NULL) { 779 s->tlsext_status_expected = 0; 780 return 1; 781 } 782 /* Set current certificate to one we will use so 783 * SSL_get_certificate et al can pick it up. 784 */ 785 s->cert->key = certpkey; 786 r = s->ctx->tlsext_status_cb(s, 787 s->ctx->tlsext_status_arg); 788 switch (r) { 789 /* We don't want to send a status request response */ 790 case SSL_TLSEXT_ERR_NOACK: 791 s->tlsext_status_expected = 0; 792 break; 793 /* status request response should be sent */ 794 case SSL_TLSEXT_ERR_OK: 795 if (s->tlsext_ocsp_resp) 796 s->tlsext_status_expected = 1; 797 else 798 s->tlsext_status_expected = 0; 799 break; 800 /* something bad happened */ 801 case SSL_TLSEXT_ERR_ALERT_FATAL: 802 ret = SSL_TLSEXT_ERR_ALERT_FATAL; 803 al = SSL_AD_INTERNAL_ERROR; 804 goto err; 805 } 806 } else 807 s->tlsext_status_expected = 0; 808 809 err: 810 switch (ret) { 811 case SSL_TLSEXT_ERR_ALERT_FATAL: 812 ssl3_send_alert(s, SSL3_AL_FATAL, al); 813 return -1; 814 case SSL_TLSEXT_ERR_ALERT_WARNING: 815 ssl3_send_alert(s, SSL3_AL_WARNING, al); 816 return 1; 817 default: 818 return 1; 819 } 820} 821 822int 823ssl_check_serverhello_tlsext(SSL *s) 824{ 825 int ret = SSL_TLSEXT_ERR_NOACK; 826 int al = SSL_AD_UNRECOGNIZED_NAME; 827 828 ret = SSL_TLSEXT_ERR_OK; 829 830 if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 831 ret = s->ctx->tlsext_servername_callback(s, &al, 832 s->ctx->tlsext_servername_arg); 833 else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0) 834 ret = s->initial_ctx->tlsext_servername_callback(s, &al, 835 s->initial_ctx->tlsext_servername_arg); 836 837 /* If we've requested certificate status and we wont get one 838 * tell the callback 839 */ 840 if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected) && 841 s->ctx && s->ctx->tlsext_status_cb) { 842 int r; 843 844 free(s->tlsext_ocsp_resp); 845 s->tlsext_ocsp_resp = NULL; 846 s->tlsext_ocsp_resp_len = 0; 847 848 r = s->ctx->tlsext_status_cb(s, 849 s->ctx->tlsext_status_arg); 850 if (r == 0) { 851 al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE; 852 ret = SSL_TLSEXT_ERR_ALERT_FATAL; 853 } 854 if (r < 0) { 855 al = SSL_AD_INTERNAL_ERROR; 856 ret = SSL_TLSEXT_ERR_ALERT_FATAL; 857 } 858 } 859 860 switch (ret) { 861 case SSL_TLSEXT_ERR_ALERT_FATAL: 862 ssl3_send_alert(s, SSL3_AL_FATAL, al); 863 return -1; 864 case SSL_TLSEXT_ERR_ALERT_WARNING: 865 ssl3_send_alert(s, SSL3_AL_WARNING, al); 866 return 1; 867 case SSL_TLSEXT_ERR_NOACK: 868 default: 869 return 1; 870 } 871} 872 873/* Since the server cache lookup is done early on in the processing of the 874 * ClientHello, and other operations depend on the result, we need to handle 875 * any TLS session ticket extension at the same time. 876 * 877 * ext_block: a CBS for the ClientHello extensions block. 878 * ret: (output) on return, if a ticket was decrypted, then this is set to 879 * point to the resulting session. 880 * 881 * If s->tls_session_secret_cb is set then we are expecting a pre-shared key 882 * ciphersuite, in which case we have no use for session tickets and one will 883 * never be decrypted, nor will s->tlsext_ticket_expected be set to 1. 884 * 885 * Returns: 886 * TLS1_TICKET_FATAL_ERROR: error from parsing or decrypting the ticket. 887 * TLS1_TICKET_NONE: no ticket was found (or was ignored, based on settings). 888 * TLS1_TICKET_EMPTY: a zero length extension was found, indicating that the 889 * client supports session tickets but doesn't currently have one to offer. 890 * TLS1_TICKET_NOT_DECRYPTED: either s->tls_session_secret_cb was 891 * set, or a ticket was offered but couldn't be decrypted because of a 892 * non-fatal error. 893 * TLS1_TICKET_DECRYPTED: a ticket was successfully decrypted and *ret was set. 894 * 895 * Side effects: 896 * Sets s->tlsext_ticket_expected to 1 if the server will have to issue 897 * a new session ticket to the client because the client indicated support 898 * (and s->tls_session_secret_cb is NULL) but the client either doesn't have 899 * a session ticket or we couldn't use the one it gave us, or if 900 * s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket. 901 * Otherwise, s->tlsext_ticket_expected is set to 0. 902 */ 903int 904tls1_process_ticket(SSL *s, CBS *ext_block, int *alert, SSL_SESSION **ret) 905{ 906 CBS extensions, ext_data; 907 uint16_t ext_type = 0; 908 909 s->tlsext_ticket_expected = 0; 910 *ret = NULL; 911 912 /* 913 * If tickets disabled behave as if no ticket present to permit stateful 914 * resumption. 915 */ 916 if (SSL_get_options(s) & SSL_OP_NO_TICKET) 917 return TLS1_TICKET_NONE; 918 919 /* 920 * An empty extensions block is valid, but obviously does not contain 921 * a session ticket. 922 */ 923 if (CBS_len(ext_block) == 0) 924 return TLS1_TICKET_NONE; 925 926 if (!CBS_get_u16_length_prefixed(ext_block, &extensions)) { 927 *alert = SSL_AD_DECODE_ERROR; 928 return TLS1_TICKET_FATAL_ERROR; 929 } 930 931 while (CBS_len(&extensions) > 0) { 932 if (!CBS_get_u16(&extensions, &ext_type) || 933 !CBS_get_u16_length_prefixed(&extensions, &ext_data)) { 934 *alert = SSL_AD_DECODE_ERROR; 935 return TLS1_TICKET_FATAL_ERROR; 936 } 937 938 if (ext_type == TLSEXT_TYPE_session_ticket) 939 break; 940 } 941 942 if (ext_type != TLSEXT_TYPE_session_ticket) 943 return TLS1_TICKET_NONE; 944 945 if (CBS_len(&ext_data) == 0) { 946 /* 947 * The client will accept a ticket but does not currently 948 * have one. 949 */ 950 s->tlsext_ticket_expected = 1; 951 return TLS1_TICKET_EMPTY; 952 } 953 954 if (s->tls_session_secret_cb != NULL) { 955 /* 956 * Indicate that the ticket could not be decrypted rather than 957 * generating the session from ticket now, trigger abbreviated 958 * handshake based on external mechanism to calculate the master 959 * secret later. 960 */ 961 return TLS1_TICKET_NOT_DECRYPTED; 962 } 963 964 return tls_decrypt_ticket(s, &ext_data, alert, ret); 965} 966 967/* tls_decrypt_ticket attempts to decrypt a session ticket. 968 * 969 * ticket: a CBS containing the body of the session ticket extension. 970 * psess: (output) on return, if a ticket was decrypted, then this is set to 971 * point to the resulting session. 972 * 973 * Returns: 974 * TLS1_TICKET_FATAL_ERROR: error from parsing or decrypting the ticket. 975 * TLS1_TICKET_NOT_DECRYPTED: the ticket couldn't be decrypted. 976 * TLS1_TICKET_DECRYPTED: a ticket was decrypted and *psess was set. 977 */ 978static int 979tls_decrypt_ticket(SSL *s, CBS *ticket, int *alert, SSL_SESSION **psess) 980{ 981 CBS ticket_name, ticket_iv, ticket_encdata, ticket_hmac; 982 SSL_SESSION *sess = NULL; 983 unsigned char *sdec = NULL; 984 size_t sdec_len = 0; 985 const unsigned char *p; 986 unsigned char hmac[EVP_MAX_MD_SIZE]; 987 HMAC_CTX *hctx = NULL; 988 EVP_CIPHER_CTX *cctx = NULL; 989 SSL_CTX *tctx = s->initial_ctx; 990 int slen, hlen, iv_len; 991 int alert_desc = SSL_AD_INTERNAL_ERROR; 992 int ret = TLS1_TICKET_FATAL_ERROR; 993 994 *psess = NULL; 995 996 if (!CBS_get_bytes(ticket, &ticket_name, 16)) 997 goto derr; 998 999 /* 1000 * Initialize session ticket encryption and HMAC contexts. 1001 */ 1002 if ((cctx = EVP_CIPHER_CTX_new()) == NULL) 1003 goto err; 1004 if ((hctx = HMAC_CTX_new()) == NULL) 1005 goto err; 1006 1007 if (tctx->tlsext_ticket_key_cb != NULL) { 1008 int rv; 1009 1010 /* 1011 * The API guarantees EVP_MAX_IV_LENGTH bytes of space for 1012 * the iv to tlsext_ticket_key_cb(). Since the total space 1013 * required for a session cookie is never less than this, 1014 * this check isn't too strict. The exact check comes later. 1015 */ 1016 if (CBS_len(ticket) < EVP_MAX_IV_LENGTH) 1017 goto derr; 1018 1019 if ((rv = tctx->tlsext_ticket_key_cb(s, 1020 (unsigned char *)CBS_data(&ticket_name), 1021 (unsigned char *)CBS_data(ticket), cctx, hctx, 0)) < 0) 1022 goto err; 1023 if (rv == 0) 1024 goto derr; 1025 if (rv == 2) { 1026 /* Renew ticket. */ 1027 s->tlsext_ticket_expected = 1; 1028 } 1029 1030 if ((iv_len = EVP_CIPHER_CTX_iv_length(cctx)) < 0) 1031 goto err; 1032 /* 1033 * Now that the cipher context is initialised, we can extract 1034 * the IV since its length is known. 1035 */ 1036 if (!CBS_get_bytes(ticket, &ticket_iv, iv_len)) 1037 goto derr; 1038 } else { 1039 /* Check that the key name matches. */ 1040 if (!CBS_mem_equal(&ticket_name, 1041 tctx->tlsext_tick_key_name, 1042 sizeof(tctx->tlsext_tick_key_name))) 1043 goto derr; 1044 if ((iv_len = EVP_CIPHER_iv_length(EVP_aes_128_cbc())) < 0) 1045 goto err; 1046 if (!CBS_get_bytes(ticket, &ticket_iv, iv_len)) 1047 goto derr; 1048 if (!EVP_DecryptInit_ex(cctx, EVP_aes_128_cbc(), NULL, 1049 tctx->tlsext_tick_aes_key, CBS_data(&ticket_iv))) 1050 goto err; 1051 if (!HMAC_Init_ex(hctx, tctx->tlsext_tick_hmac_key, 1052 sizeof(tctx->tlsext_tick_hmac_key), EVP_sha256(), 1053 NULL)) 1054 goto err; 1055 } 1056 1057 /* 1058 * Attempt to process session ticket. 1059 */ 1060 1061 if ((hlen = HMAC_size(hctx)) < 0) 1062 goto err; 1063 1064 if (hlen > CBS_len(ticket)) 1065 goto derr; 1066 if (!CBS_get_bytes(ticket, &ticket_encdata, CBS_len(ticket) - hlen)) 1067 goto derr; 1068 if (!CBS_get_bytes(ticket, &ticket_hmac, hlen)) 1069 goto derr; 1070 if (CBS_len(ticket) != 0) { 1071 alert_desc = SSL_AD_DECODE_ERROR; 1072 goto err; 1073 } 1074 1075 /* Check HMAC of encrypted ticket. */ 1076 if (HMAC_Update(hctx, CBS_data(&ticket_name), 1077 CBS_len(&ticket_name)) <= 0) 1078 goto err; 1079 if (HMAC_Update(hctx, CBS_data(&ticket_iv), 1080 CBS_len(&ticket_iv)) <= 0) 1081 goto err; 1082 if (HMAC_Update(hctx, CBS_data(&ticket_encdata), 1083 CBS_len(&ticket_encdata)) <= 0) 1084 goto err; 1085 if (HMAC_Final(hctx, hmac, &hlen) <= 0) 1086 goto err; 1087 1088 if (!CBS_mem_equal(&ticket_hmac, hmac, hlen)) 1089 goto derr; 1090 1091 /* Attempt to decrypt session data. */ 1092 sdec_len = CBS_len(&ticket_encdata); 1093 if ((sdec = calloc(1, sdec_len)) == NULL) 1094 goto err; 1095 if (EVP_DecryptUpdate(cctx, sdec, &slen, CBS_data(&ticket_encdata), 1096 CBS_len(&ticket_encdata)) <= 0) 1097 goto derr; 1098 if (EVP_DecryptFinal_ex(cctx, sdec + slen, &hlen) <= 0) 1099 goto derr; 1100 1101 slen += hlen; 1102 1103 /* 1104 * For session parse failures, indicate that we need to send a new 1105 * ticket. 1106 */ 1107 p = sdec; 1108 if ((sess = d2i_SSL_SESSION(NULL, &p, slen)) == NULL) 1109 goto derr; 1110 *psess = sess; 1111 sess = NULL; 1112 1113 ret = TLS1_TICKET_DECRYPTED; 1114 goto done; 1115 1116 derr: 1117 ERR_clear_error(); 1118 s->tlsext_ticket_expected = 1; 1119 ret = TLS1_TICKET_NOT_DECRYPTED; 1120 goto done; 1121 1122 err: 1123 *alert = alert_desc; 1124 ret = TLS1_TICKET_FATAL_ERROR; 1125 goto done; 1126 1127 done: 1128 freezero(sdec, sdec_len); 1129 EVP_CIPHER_CTX_free(cctx); 1130 HMAC_CTX_free(hctx); 1131 SSL_SESSION_free(sess); 1132 1133 return ret; 1134} 1135