1 /* $OpenBSD: ssl_srvr.c,v 1.160 2024/02/03 17:39:17 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 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. 113 * 114 * Portions of the attached software ("Contribution") are developed by 115 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. 116 * 117 * The Contribution is licensed pursuant to the OpenSSL open source 118 * license provided above. 119 * 120 * ECC cipher suite support in OpenSSL originally written by 121 * Vipul Gupta and Sumit Gupta of Sun Microsystems Laboratories. 122 * 123 */ 124 /* ==================================================================== 125 * Copyright 2005 Nokia. All rights reserved. 126 * 127 * The portions of the attached software ("Contribution") is developed by 128 * Nokia Corporation and is licensed pursuant to the OpenSSL open source 129 * license. 130 * 131 * The Contribution, originally written by Mika Kousa and Pasi Eronen of 132 * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites 133 * support (see RFC 4279) to OpenSSL. 134 * 135 * No patent licenses or other rights except those expressly stated in 136 * the OpenSSL open source license shall be deemed granted or received 137 * expressly, by implication, estoppel, or otherwise. 138 * 139 * No assurances are provided by Nokia that the Contribution does not 140 * infringe the patent or other intellectual property rights of any third 141 * party or that the license provides you with all the necessary rights 142 * to make use of the Contribution. 143 * 144 * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN 145 * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA 146 * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY 147 * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR 148 * OTHERWISE. 149 */ 150 151 #include <limits.h> 152 #include <stdio.h> 153 154 #include <openssl/bn.h> 155 #include <openssl/buffer.h> 156 #include <openssl/curve25519.h> 157 #include <openssl/evp.h> 158 #include <openssl/dh.h> 159 #include <openssl/hmac.h> 160 #include <openssl/md5.h> 161 #include <openssl/objects.h> 162 #include <openssl/opensslconf.h> 163 #include <openssl/x509.h> 164 165 #include "bytestring.h" 166 #include "dtls_local.h" 167 #include "ssl_local.h" 168 #include "ssl_sigalgs.h" 169 #include "ssl_tlsext.h" 170 171 static int ssl3_get_client_hello(SSL *s); 172 static int ssl3_send_dtls_hello_verify_request(SSL *s); 173 static int ssl3_send_server_hello(SSL *s); 174 static int ssl3_send_hello_request(SSL *s); 175 static int ssl3_send_server_certificate(SSL *s); 176 static int ssl3_send_server_key_exchange(SSL *s); 177 static int ssl3_send_certificate_request(SSL *s); 178 static int ssl3_send_server_done(SSL *s); 179 static int ssl3_get_client_certificate(SSL *s); 180 static int ssl3_get_client_key_exchange(SSL *s); 181 static int ssl3_get_cert_verify(SSL *s); 182 static int ssl3_send_newsession_ticket(SSL *s); 183 static int ssl3_send_cert_status(SSL *s); 184 static int ssl3_send_server_change_cipher_spec(SSL *s); 185 static int ssl3_send_server_finished(SSL *s); 186 static int ssl3_get_client_finished(SSL *s); 187 188 int 189 ssl3_accept(SSL *s) 190 { 191 unsigned long alg_k; 192 int new_state, state, skip = 0; 193 int listen = 0; 194 int ret = -1; 195 196 ERR_clear_error(); 197 errno = 0; 198 199 if (SSL_is_dtls(s)) 200 listen = s->d1->listen; 201 202 /* init things to blank */ 203 s->in_handshake++; 204 if (!SSL_in_init(s) || SSL_in_before(s)) 205 SSL_clear(s); 206 207 if (SSL_is_dtls(s)) 208 s->d1->listen = listen; 209 210 for (;;) { 211 state = s->s3->hs.state; 212 213 switch (s->s3->hs.state) { 214 case SSL_ST_RENEGOTIATE: 215 s->renegotiate = 1; 216 /* s->s3->hs.state=SSL_ST_ACCEPT; */ 217 218 case SSL_ST_BEFORE: 219 case SSL_ST_ACCEPT: 220 case SSL_ST_BEFORE|SSL_ST_ACCEPT: 221 case SSL_ST_OK|SSL_ST_ACCEPT: 222 s->server = 1; 223 224 ssl_info_callback(s, SSL_CB_HANDSHAKE_START, 1); 225 226 if (!ssl_legacy_stack_version(s, s->version)) { 227 SSLerror(s, ERR_R_INTERNAL_ERROR); 228 ret = -1; 229 goto end; 230 } 231 232 if (!ssl_supported_tls_version_range(s, 233 &s->s3->hs.our_min_tls_version, 234 &s->s3->hs.our_max_tls_version)) { 235 SSLerror(s, SSL_R_NO_PROTOCOLS_AVAILABLE); 236 ret = -1; 237 goto end; 238 } 239 240 if (!ssl_security_version(s, 241 s->s3->hs.our_min_tls_version)) { 242 SSLerror(s, SSL_R_VERSION_TOO_LOW); 243 ret = -1; 244 goto end; 245 } 246 247 if (!ssl3_setup_init_buffer(s)) { 248 ret = -1; 249 goto end; 250 } 251 if (!ssl3_setup_buffers(s)) { 252 ret = -1; 253 goto end; 254 } 255 256 s->init_num = 0; 257 258 if (s->s3->hs.state != SSL_ST_RENEGOTIATE) { 259 /* 260 * Ok, we now need to push on a buffering BIO 261 * so that the output is sent in a way that 262 * TCP likes :-) 263 */ 264 if (!ssl_init_wbio_buffer(s, 1)) { 265 ret = -1; 266 goto end; 267 } 268 269 if (!tls1_transcript_init(s)) { 270 ret = -1; 271 goto end; 272 } 273 274 s->s3->hs.state = SSL3_ST_SR_CLNT_HELLO_A; 275 s->ctx->stats.sess_accept++; 276 } else if (!SSL_is_dtls(s) && !s->s3->send_connection_binding) { 277 /* 278 * Server attempting to renegotiate with 279 * client that doesn't support secure 280 * renegotiation. 281 */ 282 SSLerror(s, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); 283 ssl3_send_alert(s, SSL3_AL_FATAL, 284 SSL_AD_HANDSHAKE_FAILURE); 285 ret = -1; 286 goto end; 287 } else { 288 /* 289 * s->s3->hs.state == SSL_ST_RENEGOTIATE, 290 * we will just send a HelloRequest. 291 */ 292 s->ctx->stats.sess_accept_renegotiate++; 293 s->s3->hs.state = SSL3_ST_SW_HELLO_REQ_A; 294 } 295 break; 296 297 case SSL3_ST_SW_HELLO_REQ_A: 298 case SSL3_ST_SW_HELLO_REQ_B: 299 s->shutdown = 0; 300 if (SSL_is_dtls(s)) { 301 dtls1_clear_record_buffer(s); 302 dtls1_start_timer(s); 303 } 304 ret = ssl3_send_hello_request(s); 305 if (ret <= 0) 306 goto end; 307 if (SSL_is_dtls(s)) 308 s->s3->hs.tls12.next_state = SSL3_ST_SR_CLNT_HELLO_A; 309 else 310 s->s3->hs.tls12.next_state = SSL3_ST_SW_HELLO_REQ_C; 311 s->s3->hs.state = SSL3_ST_SW_FLUSH; 312 s->init_num = 0; 313 314 if (SSL_is_dtls(s)) { 315 if (!tls1_transcript_init(s)) { 316 ret = -1; 317 goto end; 318 } 319 } 320 break; 321 322 case SSL3_ST_SW_HELLO_REQ_C: 323 s->s3->hs.state = SSL_ST_OK; 324 break; 325 326 case SSL3_ST_SR_CLNT_HELLO_A: 327 case SSL3_ST_SR_CLNT_HELLO_B: 328 case SSL3_ST_SR_CLNT_HELLO_C: 329 s->shutdown = 0; 330 if (SSL_is_dtls(s)) { 331 ret = ssl3_get_client_hello(s); 332 if (ret <= 0) 333 goto end; 334 dtls1_stop_timer(s); 335 336 if (ret == 1 && 337 (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE)) 338 s->s3->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A; 339 else 340 s->s3->hs.state = SSL3_ST_SW_SRVR_HELLO_A; 341 342 s->init_num = 0; 343 344 /* 345 * Reflect ClientHello sequence to remain 346 * stateless while listening. 347 */ 348 if (listen) { 349 tls12_record_layer_reflect_seq_num( 350 s->rl); 351 } 352 353 /* If we're just listening, stop here */ 354 if (listen && s->s3->hs.state == SSL3_ST_SW_SRVR_HELLO_A) { 355 ret = 2; 356 s->d1->listen = 0; 357 /* 358 * Set expected sequence numbers to 359 * continue the handshake. 360 */ 361 s->d1->handshake_read_seq = 2; 362 s->d1->handshake_write_seq = 1; 363 s->d1->next_handshake_write_seq = 1; 364 goto end; 365 } 366 } else { 367 if (s->rwstate != SSL_X509_LOOKUP) { 368 ret = ssl3_get_client_hello(s); 369 if (ret <= 0) 370 goto end; 371 } 372 373 s->renegotiate = 2; 374 s->s3->hs.state = SSL3_ST_SW_SRVR_HELLO_A; 375 s->init_num = 0; 376 } 377 break; 378 379 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A: 380 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B: 381 ret = ssl3_send_dtls_hello_verify_request(s); 382 if (ret <= 0) 383 goto end; 384 s->s3->hs.state = SSL3_ST_SW_FLUSH; 385 s->s3->hs.tls12.next_state = SSL3_ST_SR_CLNT_HELLO_A; 386 387 /* HelloVerifyRequest resets Finished MAC. */ 388 tls1_transcript_reset(s); 389 break; 390 391 case SSL3_ST_SW_SRVR_HELLO_A: 392 case SSL3_ST_SW_SRVR_HELLO_B: 393 if (SSL_is_dtls(s)) { 394 s->renegotiate = 2; 395 dtls1_start_timer(s); 396 } 397 ret = ssl3_send_server_hello(s); 398 if (ret <= 0) 399 goto end; 400 if (s->hit) { 401 if (s->tlsext_ticket_expected) 402 s->s3->hs.state = SSL3_ST_SW_SESSION_TICKET_A; 403 else 404 s->s3->hs.state = SSL3_ST_SW_CHANGE_A; 405 } else { 406 s->s3->hs.state = SSL3_ST_SW_CERT_A; 407 } 408 s->init_num = 0; 409 break; 410 411 case SSL3_ST_SW_CERT_A: 412 case SSL3_ST_SW_CERT_B: 413 /* Check if it is anon DH or anon ECDH. */ 414 if (!(s->s3->hs.cipher->algorithm_auth & 415 SSL_aNULL)) { 416 if (SSL_is_dtls(s)) 417 dtls1_start_timer(s); 418 ret = ssl3_send_server_certificate(s); 419 if (ret <= 0) 420 goto end; 421 if (s->tlsext_status_expected) 422 s->s3->hs.state = SSL3_ST_SW_CERT_STATUS_A; 423 else 424 s->s3->hs.state = SSL3_ST_SW_KEY_EXCH_A; 425 } else { 426 skip = 1; 427 s->s3->hs.state = SSL3_ST_SW_KEY_EXCH_A; 428 } 429 s->init_num = 0; 430 break; 431 432 case SSL3_ST_SW_KEY_EXCH_A: 433 case SSL3_ST_SW_KEY_EXCH_B: 434 alg_k = s->s3->hs.cipher->algorithm_mkey; 435 436 /* 437 * Only send if using a DH key exchange. 438 * 439 * For ECC ciphersuites, we send a ServerKeyExchange 440 * message only if the cipher suite is ECDHE. In other 441 * cases, the server certificate contains the server's 442 * public key for key exchange. 443 */ 444 if (alg_k & (SSL_kDHE|SSL_kECDHE)) { 445 if (SSL_is_dtls(s)) 446 dtls1_start_timer(s); 447 ret = ssl3_send_server_key_exchange(s); 448 if (ret <= 0) 449 goto end; 450 } else 451 skip = 1; 452 453 s->s3->hs.state = SSL3_ST_SW_CERT_REQ_A; 454 s->init_num = 0; 455 break; 456 457 case SSL3_ST_SW_CERT_REQ_A: 458 case SSL3_ST_SW_CERT_REQ_B: 459 /* 460 * Determine whether or not we need to request a 461 * certificate. 462 * 463 * Do not request a certificate if: 464 * 465 * - We did not ask for it (SSL_VERIFY_PEER is unset). 466 * 467 * - SSL_VERIFY_CLIENT_ONCE is set and we are 468 * renegotiating. 469 * 470 * - We are using an anonymous ciphersuites 471 * (see section "Certificate request" in SSL 3 drafts 472 * and in RFC 2246) ... except when the application 473 * insists on verification (against the specs, but 474 * s3_clnt.c accepts this for SSL 3). 475 */ 476 if (!(s->verify_mode & SSL_VERIFY_PEER) || 477 ((s->session->peer_cert != NULL) && 478 (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) || 479 ((s->s3->hs.cipher->algorithm_auth & 480 SSL_aNULL) && !(s->verify_mode & 481 SSL_VERIFY_FAIL_IF_NO_PEER_CERT))) { 482 /* No cert request. */ 483 skip = 1; 484 s->s3->hs.tls12.cert_request = 0; 485 s->s3->hs.state = SSL3_ST_SW_SRVR_DONE_A; 486 487 if (!SSL_is_dtls(s)) 488 tls1_transcript_free(s); 489 } else { 490 s->s3->hs.tls12.cert_request = 1; 491 if (SSL_is_dtls(s)) 492 dtls1_start_timer(s); 493 ret = ssl3_send_certificate_request(s); 494 if (ret <= 0) 495 goto end; 496 s->s3->hs.state = SSL3_ST_SW_SRVR_DONE_A; 497 s->init_num = 0; 498 } 499 break; 500 501 case SSL3_ST_SW_SRVR_DONE_A: 502 case SSL3_ST_SW_SRVR_DONE_B: 503 if (SSL_is_dtls(s)) 504 dtls1_start_timer(s); 505 ret = ssl3_send_server_done(s); 506 if (ret <= 0) 507 goto end; 508 s->s3->hs.tls12.next_state = SSL3_ST_SR_CERT_A; 509 s->s3->hs.state = SSL3_ST_SW_FLUSH; 510 s->init_num = 0; 511 break; 512 513 case SSL3_ST_SW_FLUSH: 514 /* 515 * This code originally checked to see if 516 * any data was pending using BIO_CTRL_INFO 517 * and then flushed. This caused problems 518 * as documented in PR#1939. The proposed 519 * fix doesn't completely resolve this issue 520 * as buggy implementations of BIO_CTRL_PENDING 521 * still exist. So instead we just flush 522 * unconditionally. 523 */ 524 s->rwstate = SSL_WRITING; 525 if (BIO_flush(s->wbio) <= 0) { 526 if (SSL_is_dtls(s)) { 527 /* If the write error was fatal, stop trying. */ 528 if (!BIO_should_retry(s->wbio)) { 529 s->rwstate = SSL_NOTHING; 530 s->s3->hs.state = s->s3->hs.tls12.next_state; 531 } 532 } 533 ret = -1; 534 goto end; 535 } 536 s->rwstate = SSL_NOTHING; 537 s->s3->hs.state = s->s3->hs.tls12.next_state; 538 break; 539 540 case SSL3_ST_SR_CERT_A: 541 case SSL3_ST_SR_CERT_B: 542 if (s->s3->hs.tls12.cert_request != 0) { 543 ret = ssl3_get_client_certificate(s); 544 if (ret <= 0) 545 goto end; 546 } 547 s->init_num = 0; 548 s->s3->hs.state = SSL3_ST_SR_KEY_EXCH_A; 549 break; 550 551 case SSL3_ST_SR_KEY_EXCH_A: 552 case SSL3_ST_SR_KEY_EXCH_B: 553 ret = ssl3_get_client_key_exchange(s); 554 if (ret <= 0) 555 goto end; 556 557 if (SSL_is_dtls(s)) { 558 s->s3->hs.state = SSL3_ST_SR_CERT_VRFY_A; 559 s->init_num = 0; 560 } 561 562 alg_k = s->s3->hs.cipher->algorithm_mkey; 563 if (SSL_USE_SIGALGS(s)) { 564 s->s3->hs.state = SSL3_ST_SR_CERT_VRFY_A; 565 s->init_num = 0; 566 if (!s->session->peer_cert) 567 break; 568 /* 569 * Freeze the transcript for use during client 570 * certificate verification. 571 */ 572 tls1_transcript_freeze(s); 573 } else { 574 s->s3->hs.state = SSL3_ST_SR_CERT_VRFY_A; 575 s->init_num = 0; 576 577 tls1_transcript_free(s); 578 579 /* 580 * We need to get hashes here so if there is 581 * a client cert, it can be verified. 582 */ 583 if (!tls1_transcript_hash_value(s, 584 s->s3->hs.tls12.cert_verify, 585 sizeof(s->s3->hs.tls12.cert_verify), 586 NULL)) { 587 ret = -1; 588 goto end; 589 } 590 } 591 break; 592 593 case SSL3_ST_SR_CERT_VRFY_A: 594 case SSL3_ST_SR_CERT_VRFY_B: 595 if (SSL_is_dtls(s)) 596 s->d1->change_cipher_spec_ok = 1; 597 else 598 s->s3->flags |= SSL3_FLAGS_CCS_OK; 599 600 /* we should decide if we expected this one */ 601 ret = ssl3_get_cert_verify(s); 602 if (ret <= 0) 603 goto end; 604 s->s3->hs.state = SSL3_ST_SR_FINISHED_A; 605 s->init_num = 0; 606 break; 607 608 case SSL3_ST_SR_FINISHED_A: 609 case SSL3_ST_SR_FINISHED_B: 610 if (SSL_is_dtls(s)) 611 s->d1->change_cipher_spec_ok = 1; 612 else 613 s->s3->flags |= SSL3_FLAGS_CCS_OK; 614 ret = ssl3_get_client_finished(s); 615 if (ret <= 0) 616 goto end; 617 if (SSL_is_dtls(s)) 618 dtls1_stop_timer(s); 619 if (s->hit) 620 s->s3->hs.state = SSL_ST_OK; 621 else if (s->tlsext_ticket_expected) 622 s->s3->hs.state = SSL3_ST_SW_SESSION_TICKET_A; 623 else 624 s->s3->hs.state = SSL3_ST_SW_CHANGE_A; 625 s->init_num = 0; 626 break; 627 628 case SSL3_ST_SW_SESSION_TICKET_A: 629 case SSL3_ST_SW_SESSION_TICKET_B: 630 ret = ssl3_send_newsession_ticket(s); 631 if (ret <= 0) 632 goto end; 633 s->s3->hs.state = SSL3_ST_SW_CHANGE_A; 634 s->init_num = 0; 635 break; 636 637 case SSL3_ST_SW_CERT_STATUS_A: 638 case SSL3_ST_SW_CERT_STATUS_B: 639 ret = ssl3_send_cert_status(s); 640 if (ret <= 0) 641 goto end; 642 s->s3->hs.state = SSL3_ST_SW_KEY_EXCH_A; 643 s->init_num = 0; 644 break; 645 646 case SSL3_ST_SW_CHANGE_A: 647 case SSL3_ST_SW_CHANGE_B: 648 ret = ssl3_send_server_change_cipher_spec(s); 649 if (ret <= 0) 650 goto end; 651 s->s3->hs.state = SSL3_ST_SW_FINISHED_A; 652 s->init_num = 0; 653 s->session->cipher = s->s3->hs.cipher; 654 655 if (!tls1_setup_key_block(s)) { 656 ret = -1; 657 goto end; 658 } 659 if (!tls1_change_write_cipher_state(s)) { 660 ret = -1; 661 goto end; 662 } 663 break; 664 665 case SSL3_ST_SW_FINISHED_A: 666 case SSL3_ST_SW_FINISHED_B: 667 ret = ssl3_send_server_finished(s); 668 if (ret <= 0) 669 goto end; 670 s->s3->hs.state = SSL3_ST_SW_FLUSH; 671 if (s->hit) { 672 s->s3->hs.tls12.next_state = SSL3_ST_SR_FINISHED_A; 673 tls1_transcript_free(s); 674 } else 675 s->s3->hs.tls12.next_state = SSL_ST_OK; 676 s->init_num = 0; 677 break; 678 679 case SSL_ST_OK: 680 /* clean a few things up */ 681 tls1_cleanup_key_block(s); 682 683 if (s->s3->handshake_transcript != NULL) { 684 SSLerror(s, ERR_R_INTERNAL_ERROR); 685 ret = -1; 686 goto end; 687 } 688 689 if (!SSL_is_dtls(s)) 690 ssl3_release_init_buffer(s); 691 692 /* remove buffering on output */ 693 ssl_free_wbio_buffer(s); 694 695 s->init_num = 0; 696 697 /* Skipped if we just sent a HelloRequest. */ 698 if (s->renegotiate == 2) { 699 s->renegotiate = 0; 700 s->new_session = 0; 701 702 ssl_update_cache(s, SSL_SESS_CACHE_SERVER); 703 704 s->ctx->stats.sess_accept_good++; 705 /* s->server=1; */ 706 s->handshake_func = ssl3_accept; 707 708 ssl_info_callback(s, SSL_CB_HANDSHAKE_DONE, 1); 709 } 710 711 ret = 1; 712 713 if (SSL_is_dtls(s)) { 714 /* Done handshaking, next message is client hello. */ 715 s->d1->handshake_read_seq = 0; 716 /* Next message is server hello. */ 717 s->d1->handshake_write_seq = 0; 718 s->d1->next_handshake_write_seq = 0; 719 } 720 goto end; 721 /* break; */ 722 723 default: 724 SSLerror(s, SSL_R_UNKNOWN_STATE); 725 ret = -1; 726 goto end; 727 /* break; */ 728 } 729 730 if (!s->s3->hs.tls12.reuse_message && !skip) { 731 if (s->s3->hs.state != state) { 732 new_state = s->s3->hs.state; 733 s->s3->hs.state = state; 734 ssl_info_callback(s, SSL_CB_ACCEPT_LOOP, 1); 735 s->s3->hs.state = new_state; 736 } 737 } 738 skip = 0; 739 } 740 end: 741 /* BIO_flush(s->wbio); */ 742 s->in_handshake--; 743 ssl_info_callback(s, SSL_CB_ACCEPT_EXIT, ret); 744 745 return (ret); 746 } 747 748 static int 749 ssl3_send_hello_request(SSL *s) 750 { 751 CBB cbb, hello; 752 753 memset(&cbb, 0, sizeof(cbb)); 754 755 if (s->s3->hs.state == SSL3_ST_SW_HELLO_REQ_A) { 756 if (!ssl3_handshake_msg_start(s, &cbb, &hello, 757 SSL3_MT_HELLO_REQUEST)) 758 goto err; 759 if (!ssl3_handshake_msg_finish(s, &cbb)) 760 goto err; 761 762 s->s3->hs.state = SSL3_ST_SW_HELLO_REQ_B; 763 } 764 765 /* SSL3_ST_SW_HELLO_REQ_B */ 766 return (ssl3_handshake_write(s)); 767 768 err: 769 CBB_cleanup(&cbb); 770 771 return (-1); 772 } 773 774 static int 775 ssl3_get_client_hello(SSL *s) 776 { 777 CBS cbs, client_random, session_id, cookie, cipher_suites; 778 CBS compression_methods; 779 uint16_t client_version; 780 uint8_t comp_method; 781 int comp_null; 782 int i, j, al, ret, cookie_valid = 0; 783 unsigned long id; 784 SSL_CIPHER *c; 785 STACK_OF(SSL_CIPHER) *ciphers = NULL; 786 const SSL_METHOD *method; 787 uint16_t shared_version; 788 789 /* 790 * We do this so that we will respond with our native type. 791 * If we are TLSv1 and we get SSLv3, we will respond with TLSv1, 792 * This down switching should be handled by a different method. 793 * If we are SSLv3, we will respond with SSLv3, even if prompted with 794 * TLSv1. 795 */ 796 if (s->s3->hs.state == SSL3_ST_SR_CLNT_HELLO_A) 797 s->s3->hs.state = SSL3_ST_SR_CLNT_HELLO_B; 798 799 s->first_packet = 1; 800 if ((ret = ssl3_get_message(s, SSL3_ST_SR_CLNT_HELLO_B, 801 SSL3_ST_SR_CLNT_HELLO_C, SSL3_MT_CLIENT_HELLO, 802 SSL3_RT_MAX_PLAIN_LENGTH)) <= 0) 803 return ret; 804 s->first_packet = 0; 805 806 ret = -1; 807 808 if (s->init_num < 0) 809 goto err; 810 811 CBS_init(&cbs, s->init_msg, s->init_num); 812 813 /* Parse client hello up until the extensions (if any). */ 814 if (!CBS_get_u16(&cbs, &client_version)) 815 goto decode_err; 816 if (!CBS_get_bytes(&cbs, &client_random, SSL3_RANDOM_SIZE)) 817 goto decode_err; 818 if (!CBS_get_u8_length_prefixed(&cbs, &session_id)) 819 goto decode_err; 820 if (CBS_len(&session_id) > SSL3_SESSION_ID_SIZE) { 821 al = SSL_AD_ILLEGAL_PARAMETER; 822 SSLerror(s, SSL_R_SSL3_SESSION_ID_TOO_LONG); 823 goto fatal_err; 824 } 825 if (SSL_is_dtls(s)) { 826 if (!CBS_get_u8_length_prefixed(&cbs, &cookie)) 827 goto decode_err; 828 } 829 if (!CBS_get_u16_length_prefixed(&cbs, &cipher_suites)) 830 goto decode_err; 831 if (!CBS_get_u8_length_prefixed(&cbs, &compression_methods)) 832 goto decode_err; 833 834 /* 835 * Use version from inside client hello, not from record header. 836 * (may differ: see RFC 2246, Appendix E, second paragraph) 837 */ 838 if (!ssl_max_shared_version(s, client_version, &shared_version)) { 839 if ((client_version >> 8) == SSL3_VERSION_MAJOR && 840 !tls12_record_layer_write_protected(s->rl)) { 841 /* 842 * Similar to ssl3_get_record, send alert using remote 843 * version number. 844 */ 845 s->version = client_version; 846 } 847 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 848 al = SSL_AD_PROTOCOL_VERSION; 849 goto fatal_err; 850 } 851 s->s3->hs.peer_legacy_version = client_version; 852 s->version = shared_version; 853 854 s->s3->hs.negotiated_tls_version = ssl_tls_version(shared_version); 855 if (s->s3->hs.negotiated_tls_version == 0) { 856 SSLerror(s, ERR_R_INTERNAL_ERROR); 857 goto err; 858 } 859 860 if ((method = ssl_get_method(shared_version)) == NULL) { 861 SSLerror(s, ERR_R_INTERNAL_ERROR); 862 goto err; 863 } 864 s->method = method; 865 866 /* 867 * If we require cookies (DTLS) and this ClientHello does not contain 868 * one, just return since we do not want to allocate any memory yet. 869 * So check cookie length... 870 */ 871 if (SSL_is_dtls(s)) { 872 if (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) { 873 if (CBS_len(&cookie) == 0) 874 return (1); 875 } 876 } 877 878 if (!CBS_write_bytes(&client_random, s->s3->client_random, 879 sizeof(s->s3->client_random), NULL)) 880 goto err; 881 882 s->hit = 0; 883 884 /* 885 * Versions before 0.9.7 always allow clients to resume sessions in 886 * renegotiation. 0.9.7 and later allow this by default, but optionally 887 * ignore resumption requests with flag 888 * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION (it's a new flag 889 * rather than a change to default behavior so that applications 890 * relying on this for security won't even compile against older 891 * library versions). 892 * 893 * 1.0.1 and later also have a function SSL_renegotiate_abbreviated() 894 * to request renegotiation but not a new session (s->new_session 895 * remains unset): for servers, this essentially just means that the 896 * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION setting will be 897 * ignored. 898 */ 899 if ((s->new_session && (s->options & 900 SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION))) { 901 if (!ssl_get_new_session(s, 1)) 902 goto err; 903 } else { 904 CBS ext_block; 905 906 CBS_dup(&cbs, &ext_block); 907 908 i = ssl_get_prev_session(s, &session_id, &ext_block, &al); 909 if (i == 1) { /* previous session */ 910 s->hit = 1; 911 } else if (i == -1) 912 goto fatal_err; 913 else { 914 /* i == 0 */ 915 if (!ssl_get_new_session(s, 1)) 916 goto err; 917 } 918 } 919 920 if (SSL_is_dtls(s)) { 921 /* 922 * The ClientHello may contain a cookie even if the HelloVerify 923 * message has not been sent - make sure that it does not cause 924 * an overflow. 925 */ 926 if (CBS_len(&cookie) > sizeof(s->d1->rcvd_cookie)) { 927 al = SSL_AD_DECODE_ERROR; 928 SSLerror(s, SSL_R_COOKIE_MISMATCH); 929 goto fatal_err; 930 } 931 932 /* Verify the cookie if appropriate option is set. */ 933 if ((SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) && 934 CBS_len(&cookie) > 0) { 935 size_t cookie_len; 936 937 /* XXX - rcvd_cookie seems to only be used here... */ 938 if (!CBS_write_bytes(&cookie, s->d1->rcvd_cookie, 939 sizeof(s->d1->rcvd_cookie), &cookie_len)) 940 goto err; 941 942 if (s->ctx->app_verify_cookie_cb != NULL) { 943 if (s->ctx->app_verify_cookie_cb(s, 944 s->d1->rcvd_cookie, cookie_len) == 0) { 945 al = SSL_AD_HANDSHAKE_FAILURE; 946 SSLerror(s, SSL_R_COOKIE_MISMATCH); 947 goto fatal_err; 948 } 949 /* else cookie verification succeeded */ 950 /* XXX - can d1->cookie_len > sizeof(rcvd_cookie) ? */ 951 } else if (timingsafe_memcmp(s->d1->rcvd_cookie, 952 s->d1->cookie, s->d1->cookie_len) != 0) { 953 /* default verification */ 954 al = SSL_AD_HANDSHAKE_FAILURE; 955 SSLerror(s, SSL_R_COOKIE_MISMATCH); 956 goto fatal_err; 957 } 958 cookie_valid = 1; 959 } 960 } 961 962 /* XXX - This logic seems wrong... */ 963 if (CBS_len(&cipher_suites) == 0 && CBS_len(&session_id) != 0) { 964 /* we need a cipher if we are not resuming a session */ 965 al = SSL_AD_ILLEGAL_PARAMETER; 966 SSLerror(s, SSL_R_NO_CIPHERS_SPECIFIED); 967 goto fatal_err; 968 } 969 970 if (CBS_len(&cipher_suites) > 0) { 971 if ((ciphers = ssl_bytes_to_cipher_list(s, 972 &cipher_suites)) == NULL) 973 goto err; 974 } 975 976 /* If it is a hit, check that the cipher is in the list */ 977 /* XXX - CBS_len(&cipher_suites) will always be zero here... */ 978 if (s->hit && CBS_len(&cipher_suites) > 0) { 979 j = 0; 980 id = s->session->cipher->id; 981 982 for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) { 983 c = sk_SSL_CIPHER_value(ciphers, i); 984 if (c->id == id) { 985 j = 1; 986 break; 987 } 988 } 989 if (j == 0) { 990 /* 991 * We need to have the cipher in the cipher 992 * list if we are asked to reuse it 993 */ 994 al = SSL_AD_ILLEGAL_PARAMETER; 995 SSLerror(s, SSL_R_REQUIRED_CIPHER_MISSING); 996 goto fatal_err; 997 } 998 } 999 1000 comp_null = 0; 1001 while (CBS_len(&compression_methods) > 0) { 1002 if (!CBS_get_u8(&compression_methods, &comp_method)) 1003 goto decode_err; 1004 if (comp_method == 0) 1005 comp_null = 1; 1006 } 1007 if (comp_null == 0) { 1008 al = SSL_AD_DECODE_ERROR; 1009 SSLerror(s, SSL_R_NO_COMPRESSION_SPECIFIED); 1010 goto fatal_err; 1011 } 1012 1013 if (!tlsext_server_parse(s, SSL_TLSEXT_MSG_CH, &cbs, &al)) { 1014 SSLerror(s, SSL_R_PARSE_TLSEXT); 1015 goto fatal_err; 1016 } 1017 1018 if (CBS_len(&cbs) != 0) 1019 goto decode_err; 1020 1021 if (!s->s3->renegotiate_seen && s->renegotiate) { 1022 al = SSL_AD_HANDSHAKE_FAILURE; 1023 SSLerror(s, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); 1024 goto fatal_err; 1025 } 1026 1027 if (ssl_check_clienthello_tlsext_early(s) <= 0) { 1028 SSLerror(s, SSL_R_CLIENTHELLO_TLSEXT); 1029 goto err; 1030 } 1031 1032 /* 1033 * Check if we want to use external pre-shared secret for this 1034 * handshake for not reused session only. We need to generate 1035 * server_random before calling tls_session_secret_cb in order to allow 1036 * SessionTicket processing to use it in key derivation. 1037 */ 1038 arc4random_buf(s->s3->server_random, SSL3_RANDOM_SIZE); 1039 1040 if (s->s3->hs.our_max_tls_version >= TLS1_2_VERSION && 1041 s->s3->hs.negotiated_tls_version < s->s3->hs.our_max_tls_version) { 1042 /* 1043 * RFC 8446 section 4.1.3. If we are downgrading from TLS 1.3 1044 * we must set the last 8 bytes of the server random to magical 1045 * values to indicate we meant to downgrade. For TLS 1.2 it is 1046 * recommended that we do the same. 1047 */ 1048 size_t index = SSL3_RANDOM_SIZE - sizeof(tls13_downgrade_12); 1049 uint8_t *magic = &s->s3->server_random[index]; 1050 if (s->s3->hs.negotiated_tls_version == TLS1_2_VERSION) { 1051 /* Indicate we chose to downgrade to 1.2. */ 1052 memcpy(magic, tls13_downgrade_12, 1053 sizeof(tls13_downgrade_12)); 1054 } else { 1055 /* Indicate we chose to downgrade to 1.1 or lower */ 1056 memcpy(magic, tls13_downgrade_11, 1057 sizeof(tls13_downgrade_11)); 1058 } 1059 } 1060 1061 if (!s->hit && s->tls_session_secret_cb != NULL) { 1062 SSL_CIPHER *pref_cipher = NULL; 1063 int master_key_length = sizeof(s->session->master_key); 1064 1065 if (!s->tls_session_secret_cb(s, 1066 s->session->master_key, &master_key_length, ciphers, 1067 &pref_cipher, s->tls_session_secret_cb_arg)) { 1068 SSLerror(s, ERR_R_INTERNAL_ERROR); 1069 goto err; 1070 } 1071 if (master_key_length <= 0) { 1072 SSLerror(s, ERR_R_INTERNAL_ERROR); 1073 goto err; 1074 } 1075 s->session->master_key_length = master_key_length; 1076 1077 s->hit = 1; 1078 s->session->verify_result = X509_V_OK; 1079 1080 sk_SSL_CIPHER_free(s->session->ciphers); 1081 s->session->ciphers = ciphers; 1082 ciphers = NULL; 1083 1084 /* Check if some cipher was preferred by the callback. */ 1085 if (pref_cipher == NULL) 1086 pref_cipher = ssl3_choose_cipher(s, s->session->ciphers, 1087 SSL_get_ciphers(s)); 1088 if (pref_cipher == NULL) { 1089 al = SSL_AD_HANDSHAKE_FAILURE; 1090 SSLerror(s, SSL_R_NO_SHARED_CIPHER); 1091 goto fatal_err; 1092 } 1093 s->session->cipher = pref_cipher; 1094 1095 sk_SSL_CIPHER_free(s->cipher_list); 1096 s->cipher_list = sk_SSL_CIPHER_dup(s->session->ciphers); 1097 } 1098 1099 /* 1100 * Given s->session->ciphers and SSL_get_ciphers, we must 1101 * pick a cipher 1102 */ 1103 1104 if (!s->hit) { 1105 if (ciphers == NULL) { 1106 al = SSL_AD_ILLEGAL_PARAMETER; 1107 SSLerror(s, SSL_R_NO_CIPHERS_PASSED); 1108 goto fatal_err; 1109 } 1110 sk_SSL_CIPHER_free(s->session->ciphers); 1111 s->session->ciphers = ciphers; 1112 ciphers = NULL; 1113 1114 if ((c = ssl3_choose_cipher(s, s->session->ciphers, 1115 SSL_get_ciphers(s))) == NULL) { 1116 al = SSL_AD_HANDSHAKE_FAILURE; 1117 SSLerror(s, SSL_R_NO_SHARED_CIPHER); 1118 goto fatal_err; 1119 } 1120 s->s3->hs.cipher = c; 1121 } else { 1122 s->s3->hs.cipher = s->session->cipher; 1123 } 1124 1125 if (!tls1_transcript_hash_init(s)) 1126 goto err; 1127 1128 if (!SSL_USE_SIGALGS(s) || !(s->verify_mode & SSL_VERIFY_PEER)) 1129 tls1_transcript_free(s); 1130 1131 /* 1132 * We now have the following setup. 1133 * client_random 1134 * cipher_list - our preferred list of ciphers 1135 * ciphers - the clients preferred list of ciphers 1136 * compression - basically ignored right now 1137 * ssl version is set - sslv3 1138 * s->session - The ssl session has been setup. 1139 * s->hit - session reuse flag 1140 * s->hs.cipher - the new cipher to use. 1141 */ 1142 1143 /* Handles TLS extensions that we couldn't check earlier */ 1144 if (ssl_check_clienthello_tlsext_late(s) <= 0) { 1145 SSLerror(s, SSL_R_CLIENTHELLO_TLSEXT); 1146 goto err; 1147 } 1148 1149 ret = cookie_valid ? 2 : 1; 1150 1151 if (0) { 1152 decode_err: 1153 al = SSL_AD_DECODE_ERROR; 1154 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 1155 fatal_err: 1156 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1157 } 1158 err: 1159 sk_SSL_CIPHER_free(ciphers); 1160 1161 return (ret); 1162 } 1163 1164 static int 1165 ssl3_send_dtls_hello_verify_request(SSL *s) 1166 { 1167 CBB cbb, verify, cookie; 1168 1169 memset(&cbb, 0, sizeof(cbb)); 1170 1171 if (s->s3->hs.state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) { 1172 if (s->ctx->app_gen_cookie_cb == NULL || 1173 s->ctx->app_gen_cookie_cb(s, s->d1->cookie, 1174 &(s->d1->cookie_len)) == 0) { 1175 SSLerror(s, ERR_R_INTERNAL_ERROR); 1176 return 0; 1177 } 1178 1179 /* 1180 * Per RFC 6347 section 4.2.1, the HelloVerifyRequest should 1181 * always contain DTLSv1.0 regardless of the version that is 1182 * going to be negotiated. 1183 */ 1184 if (!ssl3_handshake_msg_start(s, &cbb, &verify, 1185 DTLS1_MT_HELLO_VERIFY_REQUEST)) 1186 goto err; 1187 if (!CBB_add_u16(&verify, DTLS1_VERSION)) 1188 goto err; 1189 if (!CBB_add_u8_length_prefixed(&verify, &cookie)) 1190 goto err; 1191 if (!CBB_add_bytes(&cookie, s->d1->cookie, s->d1->cookie_len)) 1192 goto err; 1193 if (!ssl3_handshake_msg_finish(s, &cbb)) 1194 goto err; 1195 1196 s->s3->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B; 1197 } 1198 1199 /* s->s3->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */ 1200 return (ssl3_handshake_write(s)); 1201 1202 err: 1203 CBB_cleanup(&cbb); 1204 1205 return (-1); 1206 } 1207 1208 static int 1209 ssl3_send_server_hello(SSL *s) 1210 { 1211 CBB cbb, server_hello, session_id; 1212 size_t sl; 1213 1214 memset(&cbb, 0, sizeof(cbb)); 1215 1216 if (s->s3->hs.state == SSL3_ST_SW_SRVR_HELLO_A) { 1217 if (!ssl3_handshake_msg_start(s, &cbb, &server_hello, 1218 SSL3_MT_SERVER_HELLO)) 1219 goto err; 1220 1221 if (!CBB_add_u16(&server_hello, s->version)) 1222 goto err; 1223 if (!CBB_add_bytes(&server_hello, s->s3->server_random, 1224 sizeof(s->s3->server_random))) 1225 goto err; 1226 1227 /* 1228 * There are several cases for the session ID to send 1229 * back in the server hello: 1230 * 1231 * - For session reuse from the session cache, 1232 * we send back the old session ID. 1233 * - If stateless session reuse (using a session ticket) 1234 * is successful, we send back the client's "session ID" 1235 * (which doesn't actually identify the session). 1236 * - If it is a new session, we send back the new 1237 * session ID. 1238 * - However, if we want the new session to be single-use, 1239 * we send back a 0-length session ID. 1240 * 1241 * s->hit is non-zero in either case of session reuse, 1242 * so the following won't overwrite an ID that we're supposed 1243 * to send back. 1244 */ 1245 if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER) 1246 && !s->hit) 1247 s->session->session_id_length = 0; 1248 1249 sl = s->session->session_id_length; 1250 if (sl > sizeof(s->session->session_id)) { 1251 SSLerror(s, ERR_R_INTERNAL_ERROR); 1252 goto err; 1253 } 1254 if (!CBB_add_u8_length_prefixed(&server_hello, &session_id)) 1255 goto err; 1256 if (!CBB_add_bytes(&session_id, s->session->session_id, sl)) 1257 goto err; 1258 1259 /* Cipher suite. */ 1260 if (!CBB_add_u16(&server_hello, 1261 ssl3_cipher_get_value(s->s3->hs.cipher))) 1262 goto err; 1263 1264 /* Compression method (null). */ 1265 if (!CBB_add_u8(&server_hello, 0)) 1266 goto err; 1267 1268 /* TLS extensions */ 1269 if (!tlsext_server_build(s, SSL_TLSEXT_MSG_SH, &server_hello)) { 1270 SSLerror(s, ERR_R_INTERNAL_ERROR); 1271 goto err; 1272 } 1273 1274 if (!ssl3_handshake_msg_finish(s, &cbb)) 1275 goto err; 1276 } 1277 1278 /* SSL3_ST_SW_SRVR_HELLO_B */ 1279 return (ssl3_handshake_write(s)); 1280 1281 err: 1282 CBB_cleanup(&cbb); 1283 1284 return (-1); 1285 } 1286 1287 static int 1288 ssl3_send_server_done(SSL *s) 1289 { 1290 CBB cbb, done; 1291 1292 memset(&cbb, 0, sizeof(cbb)); 1293 1294 if (s->s3->hs.state == SSL3_ST_SW_SRVR_DONE_A) { 1295 if (!ssl3_handshake_msg_start(s, &cbb, &done, 1296 SSL3_MT_SERVER_DONE)) 1297 goto err; 1298 if (!ssl3_handshake_msg_finish(s, &cbb)) 1299 goto err; 1300 1301 s->s3->hs.state = SSL3_ST_SW_SRVR_DONE_B; 1302 } 1303 1304 /* SSL3_ST_SW_SRVR_DONE_B */ 1305 return (ssl3_handshake_write(s)); 1306 1307 err: 1308 CBB_cleanup(&cbb); 1309 1310 return (-1); 1311 } 1312 1313 static int 1314 ssl3_send_server_kex_dhe(SSL *s, CBB *cbb) 1315 { 1316 int nid = NID_dhKeyAgreement; 1317 1318 tls_key_share_free(s->s3->hs.key_share); 1319 if ((s->s3->hs.key_share = tls_key_share_new_nid(nid)) == NULL) 1320 goto err; 1321 1322 if (s->cert->dhe_params_auto != 0) { 1323 size_t key_bits; 1324 1325 if ((key_bits = ssl_dhe_params_auto_key_bits(s)) == 0) { 1326 SSLerror(s, ERR_R_INTERNAL_ERROR); 1327 ssl3_send_alert(s, SSL3_AL_FATAL, 1328 SSL_AD_INTERNAL_ERROR); 1329 goto err; 1330 } 1331 tls_key_share_set_key_bits(s->s3->hs.key_share, 1332 key_bits); 1333 } else { 1334 DH *dh_params = s->cert->dhe_params; 1335 1336 if (dh_params == NULL && s->cert->dhe_params_cb != NULL) 1337 dh_params = s->cert->dhe_params_cb(s, 0, 1338 SSL_C_PKEYLENGTH(s->s3->hs.cipher)); 1339 1340 if (dh_params == NULL) { 1341 SSLerror(s, SSL_R_MISSING_TMP_DH_KEY); 1342 ssl3_send_alert(s, SSL3_AL_FATAL, 1343 SSL_AD_HANDSHAKE_FAILURE); 1344 goto err; 1345 } 1346 1347 if (!tls_key_share_set_dh_params(s->s3->hs.key_share, dh_params)) 1348 goto err; 1349 } 1350 1351 if (!tls_key_share_generate(s->s3->hs.key_share)) 1352 goto err; 1353 1354 if (!tls_key_share_params(s->s3->hs.key_share, cbb)) 1355 goto err; 1356 if (!tls_key_share_public(s->s3->hs.key_share, cbb)) 1357 goto err; 1358 1359 if (!tls_key_share_peer_security(s, s->s3->hs.key_share)) { 1360 SSLerror(s, SSL_R_DH_KEY_TOO_SMALL); 1361 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); 1362 return 0; 1363 } 1364 1365 return 1; 1366 1367 err: 1368 return 0; 1369 } 1370 1371 static int 1372 ssl3_send_server_kex_ecdhe(SSL *s, CBB *cbb) 1373 { 1374 CBB public; 1375 int nid; 1376 1377 if (!tls1_get_supported_group(s, &nid)) { 1378 SSLerror(s, SSL_R_UNSUPPORTED_ELLIPTIC_CURVE); 1379 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); 1380 goto err; 1381 } 1382 1383 tls_key_share_free(s->s3->hs.key_share); 1384 if ((s->s3->hs.key_share = tls_key_share_new_nid(nid)) == NULL) 1385 goto err; 1386 1387 if (!tls_key_share_generate(s->s3->hs.key_share)) 1388 goto err; 1389 1390 /* 1391 * ECC key exchange - see RFC 8422, section 5.4. 1392 */ 1393 if (!CBB_add_u8(cbb, NAMED_CURVE_TYPE)) 1394 goto err; 1395 if (!CBB_add_u16(cbb, tls_key_share_group(s->s3->hs.key_share))) 1396 goto err; 1397 if (!CBB_add_u8_length_prefixed(cbb, &public)) 1398 goto err; 1399 if (!tls_key_share_public(s->s3->hs.key_share, &public)) 1400 goto err; 1401 if (!CBB_flush(cbb)) 1402 goto err; 1403 1404 return 1; 1405 1406 err: 1407 return 0; 1408 } 1409 1410 static int 1411 ssl3_send_server_key_exchange(SSL *s) 1412 { 1413 CBB cbb, cbb_signature, cbb_signed_params, server_kex; 1414 CBS params; 1415 const struct ssl_sigalg *sigalg = NULL; 1416 unsigned char *signed_params = NULL; 1417 size_t signed_params_len; 1418 unsigned char *signature = NULL; 1419 size_t signature_len = 0; 1420 const EVP_MD *md = NULL; 1421 unsigned long type; 1422 EVP_MD_CTX *md_ctx = NULL; 1423 EVP_PKEY_CTX *pctx; 1424 EVP_PKEY *pkey; 1425 int al; 1426 1427 memset(&cbb, 0, sizeof(cbb)); 1428 memset(&cbb_signed_params, 0, sizeof(cbb_signed_params)); 1429 1430 if ((md_ctx = EVP_MD_CTX_new()) == NULL) 1431 goto err; 1432 1433 if (s->s3->hs.state == SSL3_ST_SW_KEY_EXCH_A) { 1434 1435 if (!ssl3_handshake_msg_start(s, &cbb, &server_kex, 1436 SSL3_MT_SERVER_KEY_EXCHANGE)) 1437 goto err; 1438 1439 if (!CBB_init(&cbb_signed_params, 0)) 1440 goto err; 1441 1442 if (!CBB_add_bytes(&cbb_signed_params, s->s3->client_random, 1443 SSL3_RANDOM_SIZE)) { 1444 SSLerror(s, ERR_R_INTERNAL_ERROR); 1445 goto err; 1446 } 1447 if (!CBB_add_bytes(&cbb_signed_params, s->s3->server_random, 1448 SSL3_RANDOM_SIZE)) { 1449 SSLerror(s, ERR_R_INTERNAL_ERROR); 1450 goto err; 1451 } 1452 1453 type = s->s3->hs.cipher->algorithm_mkey; 1454 if (type & SSL_kDHE) { 1455 if (!ssl3_send_server_kex_dhe(s, &cbb_signed_params)) 1456 goto err; 1457 } else if (type & SSL_kECDHE) { 1458 if (!ssl3_send_server_kex_ecdhe(s, &cbb_signed_params)) 1459 goto err; 1460 } else { 1461 al = SSL_AD_HANDSHAKE_FAILURE; 1462 SSLerror(s, SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE); 1463 goto fatal_err; 1464 } 1465 1466 if (!CBB_finish(&cbb_signed_params, &signed_params, 1467 &signed_params_len)) 1468 goto err; 1469 1470 CBS_init(¶ms, signed_params, signed_params_len); 1471 if (!CBS_skip(¶ms, 2 * SSL3_RANDOM_SIZE)) 1472 goto err; 1473 1474 if (!CBB_add_bytes(&server_kex, CBS_data(¶ms), 1475 CBS_len(¶ms))) 1476 goto err; 1477 1478 /* Add signature unless anonymous. */ 1479 if (!(s->s3->hs.cipher->algorithm_auth & SSL_aNULL)) { 1480 if ((pkey = ssl_get_sign_pkey(s, s->s3->hs.cipher, 1481 &md, &sigalg)) == NULL) { 1482 al = SSL_AD_DECODE_ERROR; 1483 goto fatal_err; 1484 } 1485 s->s3->hs.our_sigalg = sigalg; 1486 1487 /* Send signature algorithm. */ 1488 if (SSL_USE_SIGALGS(s)) { 1489 if (!CBB_add_u16(&server_kex, sigalg->value)) { 1490 al = SSL_AD_INTERNAL_ERROR; 1491 SSLerror(s, ERR_R_INTERNAL_ERROR); 1492 goto fatal_err; 1493 } 1494 } 1495 1496 if (!EVP_DigestSignInit(md_ctx, &pctx, md, NULL, pkey)) { 1497 SSLerror(s, ERR_R_EVP_LIB); 1498 goto err; 1499 } 1500 if ((sigalg->flags & SIGALG_FLAG_RSA_PSS) && 1501 (!EVP_PKEY_CTX_set_rsa_padding(pctx, 1502 RSA_PKCS1_PSS_PADDING) || 1503 !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1))) { 1504 SSLerror(s, ERR_R_EVP_LIB); 1505 goto err; 1506 } 1507 if (!EVP_DigestSign(md_ctx, NULL, &signature_len, 1508 signed_params, signed_params_len)) { 1509 SSLerror(s, ERR_R_EVP_LIB); 1510 goto err; 1511 } 1512 if ((signature = calloc(1, signature_len)) == NULL) { 1513 SSLerror(s, ERR_R_MALLOC_FAILURE); 1514 goto err; 1515 } 1516 if (!EVP_DigestSign(md_ctx, signature, &signature_len, 1517 signed_params, signed_params_len)) { 1518 SSLerror(s, ERR_R_EVP_LIB); 1519 goto err; 1520 } 1521 1522 if (!CBB_add_u16_length_prefixed(&server_kex, 1523 &cbb_signature)) 1524 goto err; 1525 if (!CBB_add_bytes(&cbb_signature, signature, 1526 signature_len)) 1527 goto err; 1528 } 1529 1530 if (!ssl3_handshake_msg_finish(s, &cbb)) 1531 goto err; 1532 1533 s->s3->hs.state = SSL3_ST_SW_KEY_EXCH_B; 1534 } 1535 1536 EVP_MD_CTX_free(md_ctx); 1537 free(signature); 1538 free(signed_params); 1539 1540 return (ssl3_handshake_write(s)); 1541 1542 fatal_err: 1543 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1544 err: 1545 CBB_cleanup(&cbb_signed_params); 1546 CBB_cleanup(&cbb); 1547 EVP_MD_CTX_free(md_ctx); 1548 free(signature); 1549 free(signed_params); 1550 1551 return (-1); 1552 } 1553 1554 static int 1555 ssl3_send_certificate_request(SSL *s) 1556 { 1557 CBB cbb, cert_request, cert_types, sigalgs, cert_auth, dn; 1558 STACK_OF(X509_NAME) *sk = NULL; 1559 X509_NAME *name; 1560 int i; 1561 1562 /* 1563 * Certificate Request - RFC 5246 section 7.4.4. 1564 */ 1565 1566 memset(&cbb, 0, sizeof(cbb)); 1567 1568 if (s->s3->hs.state == SSL3_ST_SW_CERT_REQ_A) { 1569 if (!ssl3_handshake_msg_start(s, &cbb, &cert_request, 1570 SSL3_MT_CERTIFICATE_REQUEST)) 1571 goto err; 1572 1573 if (!CBB_add_u8_length_prefixed(&cert_request, &cert_types)) 1574 goto err; 1575 if (!ssl3_get_req_cert_types(s, &cert_types)) 1576 goto err; 1577 1578 if (SSL_USE_SIGALGS(s)) { 1579 if (!CBB_add_u16_length_prefixed(&cert_request, 1580 &sigalgs)) 1581 goto err; 1582 if (!ssl_sigalgs_build(s->s3->hs.negotiated_tls_version, 1583 &sigalgs, SSL_get_security_level(s))) 1584 goto err; 1585 } 1586 1587 if (!CBB_add_u16_length_prefixed(&cert_request, &cert_auth)) 1588 goto err; 1589 1590 sk = SSL_get_client_CA_list(s); 1591 for (i = 0; i < sk_X509_NAME_num(sk); i++) { 1592 unsigned char *name_data; 1593 size_t name_len; 1594 1595 name = sk_X509_NAME_value(sk, i); 1596 name_len = i2d_X509_NAME(name, NULL); 1597 1598 if (!CBB_add_u16_length_prefixed(&cert_auth, &dn)) 1599 goto err; 1600 if (!CBB_add_space(&dn, &name_data, name_len)) 1601 goto err; 1602 if (i2d_X509_NAME(name, &name_data) != name_len) 1603 goto err; 1604 } 1605 1606 if (!ssl3_handshake_msg_finish(s, &cbb)) 1607 goto err; 1608 1609 s->s3->hs.state = SSL3_ST_SW_CERT_REQ_B; 1610 } 1611 1612 /* SSL3_ST_SW_CERT_REQ_B */ 1613 return (ssl3_handshake_write(s)); 1614 1615 err: 1616 CBB_cleanup(&cbb); 1617 1618 return (-1); 1619 } 1620 1621 static int 1622 ssl3_get_client_kex_rsa(SSL *s, CBS *cbs) 1623 { 1624 unsigned char fakekey[SSL_MAX_MASTER_KEY_LENGTH]; 1625 unsigned char *pms = NULL; 1626 unsigned char *p; 1627 size_t pms_len = 0; 1628 EVP_PKEY *pkey = NULL; 1629 RSA *rsa = NULL; 1630 CBS enc_pms; 1631 int decrypt_len; 1632 int al = -1; 1633 1634 arc4random_buf(fakekey, sizeof(fakekey)); 1635 1636 fakekey[0] = s->s3->hs.peer_legacy_version >> 8; 1637 fakekey[1] = s->s3->hs.peer_legacy_version & 0xff; 1638 1639 pkey = s->cert->pkeys[SSL_PKEY_RSA].privatekey; 1640 if (pkey == NULL || (rsa = EVP_PKEY_get0_RSA(pkey)) == NULL) { 1641 al = SSL_AD_HANDSHAKE_FAILURE; 1642 SSLerror(s, SSL_R_MISSING_RSA_CERTIFICATE); 1643 goto fatal_err; 1644 } 1645 1646 pms_len = RSA_size(rsa); 1647 if (pms_len < SSL_MAX_MASTER_KEY_LENGTH) 1648 goto err; 1649 if ((pms = malloc(pms_len)) == NULL) 1650 goto err; 1651 p = pms; 1652 1653 if (!CBS_get_u16_length_prefixed(cbs, &enc_pms)) 1654 goto decode_err; 1655 if (CBS_len(cbs) != 0 || CBS_len(&enc_pms) != RSA_size(rsa)) { 1656 SSLerror(s, SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG); 1657 goto err; 1658 } 1659 1660 decrypt_len = RSA_private_decrypt(CBS_len(&enc_pms), CBS_data(&enc_pms), 1661 pms, rsa, RSA_PKCS1_PADDING); 1662 1663 ERR_clear_error(); 1664 1665 if (decrypt_len != SSL_MAX_MASTER_KEY_LENGTH) { 1666 al = SSL_AD_DECODE_ERROR; 1667 /* SSLerror(s, SSL_R_BAD_RSA_DECRYPT); */ 1668 } 1669 1670 if ((al == -1) && !((pms[0] == (s->s3->hs.peer_legacy_version >> 8)) && 1671 (pms[1] == (s->s3->hs.peer_legacy_version & 0xff)))) { 1672 /* 1673 * The premaster secret must contain the same version number 1674 * as the ClientHello to detect version rollback attacks 1675 * (strangely, the protocol does not offer such protection for 1676 * DH ciphersuites). 1677 * 1678 * The Klima-Pokorny-Rosa extension of Bleichenbacher's attack 1679 * (http://eprint.iacr.org/2003/052/) exploits the version 1680 * number check as a "bad version oracle" -- an alert would 1681 * reveal that the plaintext corresponding to some ciphertext 1682 * made up by the adversary is properly formatted except that 1683 * the version number is wrong. To avoid such attacks, we should 1684 * treat this just like any other decryption error. 1685 */ 1686 al = SSL_AD_DECODE_ERROR; 1687 /* SSLerror(s, SSL_R_BAD_PROTOCOL_VERSION_NUMBER); */ 1688 } 1689 1690 if (al != -1) { 1691 /* 1692 * Some decryption failure -- use random value instead 1693 * as countermeasure against Bleichenbacher's attack 1694 * on PKCS #1 v1.5 RSA padding (see RFC 2246, 1695 * section 7.4.7.1). 1696 */ 1697 p = fakekey; 1698 } 1699 1700 if (!tls12_derive_master_secret(s, p, SSL_MAX_MASTER_KEY_LENGTH)) 1701 goto err; 1702 1703 freezero(pms, pms_len); 1704 1705 return 1; 1706 1707 decode_err: 1708 al = SSL_AD_DECODE_ERROR; 1709 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 1710 fatal_err: 1711 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1712 err: 1713 freezero(pms, pms_len); 1714 1715 return 0; 1716 } 1717 1718 static int 1719 ssl3_get_client_kex_dhe(SSL *s, CBS *cbs) 1720 { 1721 uint8_t *key = NULL; 1722 size_t key_len = 0; 1723 int decode_error, invalid_key; 1724 int ret = 0; 1725 1726 if (s->s3->hs.key_share == NULL) { 1727 SSLerror(s, SSL_R_MISSING_TMP_DH_KEY); 1728 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); 1729 goto err; 1730 } 1731 1732 if (!tls_key_share_peer_public(s->s3->hs.key_share, cbs, 1733 &decode_error, &invalid_key)) { 1734 if (decode_error) { 1735 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 1736 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 1737 } 1738 goto err; 1739 } 1740 if (invalid_key) { 1741 SSLerror(s, SSL_R_BAD_DH_PUB_KEY_LENGTH); 1742 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); 1743 goto err; 1744 } 1745 1746 if (!tls_key_share_derive(s->s3->hs.key_share, &key, &key_len)) 1747 goto err; 1748 1749 if (!tls12_derive_master_secret(s, key, key_len)) 1750 goto err; 1751 1752 ret = 1; 1753 1754 err: 1755 freezero(key, key_len); 1756 1757 return ret; 1758 } 1759 1760 static int 1761 ssl3_get_client_kex_ecdhe(SSL *s, CBS *cbs) 1762 { 1763 uint8_t *key = NULL; 1764 size_t key_len = 0; 1765 int decode_error; 1766 CBS public; 1767 int ret = 0; 1768 1769 if (s->s3->hs.key_share == NULL) { 1770 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); 1771 SSLerror(s, SSL_R_MISSING_TMP_DH_KEY); 1772 goto err; 1773 } 1774 1775 if (!CBS_get_u8_length_prefixed(cbs, &public)) { 1776 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 1777 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 1778 goto err; 1779 } 1780 if (!tls_key_share_peer_public(s->s3->hs.key_share, &public, 1781 &decode_error, NULL)) { 1782 if (decode_error) { 1783 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 1784 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 1785 } 1786 goto err; 1787 } 1788 1789 if (!tls_key_share_derive(s->s3->hs.key_share, &key, &key_len)) 1790 goto err; 1791 1792 if (!tls12_derive_master_secret(s, key, key_len)) 1793 goto err; 1794 1795 ret = 1; 1796 1797 err: 1798 freezero(key, key_len); 1799 1800 return ret; 1801 } 1802 1803 static int 1804 ssl3_get_client_key_exchange(SSL *s) 1805 { 1806 unsigned long alg_k; 1807 int al, ret; 1808 CBS cbs; 1809 1810 /* 2048 maxlen is a guess. How long a key does that permit? */ 1811 if ((ret = ssl3_get_message(s, SSL3_ST_SR_KEY_EXCH_A, 1812 SSL3_ST_SR_KEY_EXCH_B, SSL3_MT_CLIENT_KEY_EXCHANGE, 2048)) <= 0) 1813 return ret; 1814 1815 if (s->init_num < 0) 1816 goto err; 1817 1818 CBS_init(&cbs, s->init_msg, s->init_num); 1819 1820 alg_k = s->s3->hs.cipher->algorithm_mkey; 1821 1822 if (alg_k & SSL_kRSA) { 1823 if (!ssl3_get_client_kex_rsa(s, &cbs)) 1824 goto err; 1825 } else if (alg_k & SSL_kDHE) { 1826 if (!ssl3_get_client_kex_dhe(s, &cbs)) 1827 goto err; 1828 } else if (alg_k & SSL_kECDHE) { 1829 if (!ssl3_get_client_kex_ecdhe(s, &cbs)) 1830 goto err; 1831 } else { 1832 al = SSL_AD_HANDSHAKE_FAILURE; 1833 SSLerror(s, SSL_R_UNKNOWN_CIPHER_TYPE); 1834 goto fatal_err; 1835 } 1836 1837 if (CBS_len(&cbs) != 0) { 1838 al = SSL_AD_DECODE_ERROR; 1839 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 1840 goto fatal_err; 1841 } 1842 1843 return (1); 1844 1845 fatal_err: 1846 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1847 err: 1848 return (-1); 1849 } 1850 1851 static int 1852 ssl3_get_cert_verify(SSL *s) 1853 { 1854 CBS cbs, signature; 1855 const struct ssl_sigalg *sigalg = NULL; 1856 uint16_t sigalg_value = SIGALG_NONE; 1857 EVP_PKEY *pkey; 1858 X509 *peer_cert = NULL; 1859 EVP_MD_CTX *mctx = NULL; 1860 int al, verify; 1861 const unsigned char *hdata; 1862 size_t hdatalen; 1863 int type = 0; 1864 int ret; 1865 1866 if ((ret = ssl3_get_message(s, SSL3_ST_SR_CERT_VRFY_A, 1867 SSL3_ST_SR_CERT_VRFY_B, -1, SSL3_RT_MAX_PLAIN_LENGTH)) <= 0) 1868 return ret; 1869 1870 ret = 0; 1871 1872 if (s->init_num < 0) 1873 goto err; 1874 1875 if ((mctx = EVP_MD_CTX_new()) == NULL) 1876 goto err; 1877 1878 CBS_init(&cbs, s->init_msg, s->init_num); 1879 1880 peer_cert = s->session->peer_cert; 1881 pkey = X509_get0_pubkey(peer_cert); 1882 type = X509_certificate_type(peer_cert, pkey); 1883 1884 if (s->s3->hs.tls12.message_type != SSL3_MT_CERTIFICATE_VERIFY) { 1885 s->s3->hs.tls12.reuse_message = 1; 1886 if (peer_cert != NULL) { 1887 al = SSL_AD_UNEXPECTED_MESSAGE; 1888 SSLerror(s, SSL_R_MISSING_VERIFY_MESSAGE); 1889 goto fatal_err; 1890 } 1891 ret = 1; 1892 goto end; 1893 } 1894 1895 if (peer_cert == NULL) { 1896 SSLerror(s, SSL_R_NO_CLIENT_CERT_RECEIVED); 1897 al = SSL_AD_UNEXPECTED_MESSAGE; 1898 goto fatal_err; 1899 } 1900 1901 if (!(type & EVP_PKT_SIGN)) { 1902 SSLerror(s, SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE); 1903 al = SSL_AD_ILLEGAL_PARAMETER; 1904 goto fatal_err; 1905 } 1906 1907 if (s->s3->change_cipher_spec) { 1908 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1909 al = SSL_AD_UNEXPECTED_MESSAGE; 1910 goto fatal_err; 1911 } 1912 1913 if (SSL_USE_SIGALGS(s)) { 1914 if (!CBS_get_u16(&cbs, &sigalg_value)) 1915 goto decode_err; 1916 } 1917 if (!CBS_get_u16_length_prefixed(&cbs, &signature)) 1918 goto err; 1919 if (CBS_len(&cbs) != 0) { 1920 al = SSL_AD_DECODE_ERROR; 1921 SSLerror(s, SSL_R_EXTRA_DATA_IN_MESSAGE); 1922 goto fatal_err; 1923 } 1924 1925 if (CBS_len(&signature) > EVP_PKEY_size(pkey)) { 1926 SSLerror(s, SSL_R_WRONG_SIGNATURE_SIZE); 1927 al = SSL_AD_DECODE_ERROR; 1928 goto fatal_err; 1929 } 1930 1931 if ((sigalg = ssl_sigalg_for_peer(s, pkey, 1932 sigalg_value)) == NULL) { 1933 al = SSL_AD_DECODE_ERROR; 1934 goto fatal_err; 1935 } 1936 s->s3->hs.peer_sigalg = sigalg; 1937 1938 if (SSL_USE_SIGALGS(s)) { 1939 EVP_PKEY_CTX *pctx; 1940 1941 if (!tls1_transcript_data(s, &hdata, &hdatalen)) { 1942 SSLerror(s, ERR_R_INTERNAL_ERROR); 1943 al = SSL_AD_INTERNAL_ERROR; 1944 goto fatal_err; 1945 } 1946 if (!EVP_DigestVerifyInit(mctx, &pctx, sigalg->md(), 1947 NULL, pkey)) { 1948 SSLerror(s, ERR_R_EVP_LIB); 1949 al = SSL_AD_INTERNAL_ERROR; 1950 goto fatal_err; 1951 } 1952 if ((sigalg->flags & SIGALG_FLAG_RSA_PSS) && 1953 (!EVP_PKEY_CTX_set_rsa_padding(pctx, 1954 RSA_PKCS1_PSS_PADDING) || 1955 !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1))) { 1956 al = SSL_AD_INTERNAL_ERROR; 1957 goto fatal_err; 1958 } 1959 if (EVP_DigestVerify(mctx, CBS_data(&signature), 1960 CBS_len(&signature), hdata, hdatalen) <= 0) { 1961 SSLerror(s, ERR_R_EVP_LIB); 1962 al = SSL_AD_INTERNAL_ERROR; 1963 goto fatal_err; 1964 } 1965 } else if (EVP_PKEY_id(pkey) == EVP_PKEY_RSA) { 1966 RSA *rsa; 1967 1968 if ((rsa = EVP_PKEY_get0_RSA(pkey)) == NULL) { 1969 al = SSL_AD_INTERNAL_ERROR; 1970 SSLerror(s, ERR_R_EVP_LIB); 1971 goto fatal_err; 1972 } 1973 verify = RSA_verify(NID_md5_sha1, s->s3->hs.tls12.cert_verify, 1974 MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH, CBS_data(&signature), 1975 CBS_len(&signature), rsa); 1976 if (verify < 0) { 1977 al = SSL_AD_DECRYPT_ERROR; 1978 SSLerror(s, SSL_R_BAD_RSA_DECRYPT); 1979 goto fatal_err; 1980 } 1981 if (verify == 0) { 1982 al = SSL_AD_DECRYPT_ERROR; 1983 SSLerror(s, SSL_R_BAD_RSA_SIGNATURE); 1984 goto fatal_err; 1985 } 1986 } else if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) { 1987 EC_KEY *eckey; 1988 1989 if ((eckey = EVP_PKEY_get0_EC_KEY(pkey)) == NULL) { 1990 al = SSL_AD_INTERNAL_ERROR; 1991 SSLerror(s, ERR_R_EVP_LIB); 1992 goto fatal_err; 1993 } 1994 verify = ECDSA_verify(0, 1995 &(s->s3->hs.tls12.cert_verify[MD5_DIGEST_LENGTH]), 1996 SHA_DIGEST_LENGTH, CBS_data(&signature), 1997 CBS_len(&signature), eckey); 1998 if (verify <= 0) { 1999 al = SSL_AD_DECRYPT_ERROR; 2000 SSLerror(s, SSL_R_BAD_ECDSA_SIGNATURE); 2001 goto fatal_err; 2002 } 2003 } else { 2004 SSLerror(s, ERR_R_INTERNAL_ERROR); 2005 al = SSL_AD_UNSUPPORTED_CERTIFICATE; 2006 goto fatal_err; 2007 } 2008 2009 ret = 1; 2010 if (0) { 2011 decode_err: 2012 al = SSL_AD_DECODE_ERROR; 2013 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 2014 fatal_err: 2015 ssl3_send_alert(s, SSL3_AL_FATAL, al); 2016 } 2017 end: 2018 tls1_transcript_free(s); 2019 err: 2020 EVP_MD_CTX_free(mctx); 2021 2022 return (ret); 2023 } 2024 2025 static int 2026 ssl3_get_client_certificate(SSL *s) 2027 { 2028 CBS cbs, cert_list, cert_data; 2029 STACK_OF(X509) *certs = NULL; 2030 X509 *cert = NULL; 2031 const uint8_t *p; 2032 int al, ret; 2033 2034 if ((ret = ssl3_get_message(s, SSL3_ST_SR_CERT_A, SSL3_ST_SR_CERT_B, 2035 -1, s->max_cert_list)) <= 0) 2036 return ret; 2037 2038 ret = -1; 2039 2040 if (s->s3->hs.tls12.message_type == SSL3_MT_CLIENT_KEY_EXCHANGE) { 2041 if ((s->verify_mode & SSL_VERIFY_PEER) && 2042 (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) { 2043 SSLerror(s, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE); 2044 al = SSL_AD_HANDSHAKE_FAILURE; 2045 goto fatal_err; 2046 } 2047 2048 /* 2049 * If we asked for a client certificate and the client has none, 2050 * it must respond with a certificate list of length zero. 2051 */ 2052 if (s->s3->hs.tls12.cert_request != 0) { 2053 SSLerror(s, SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST); 2054 al = SSL_AD_UNEXPECTED_MESSAGE; 2055 goto fatal_err; 2056 } 2057 s->s3->hs.tls12.reuse_message = 1; 2058 return (1); 2059 } 2060 2061 if (s->s3->hs.tls12.message_type != SSL3_MT_CERTIFICATE) { 2062 al = SSL_AD_UNEXPECTED_MESSAGE; 2063 SSLerror(s, SSL_R_WRONG_MESSAGE_TYPE); 2064 goto fatal_err; 2065 } 2066 2067 if (s->init_num < 0) 2068 goto decode_err; 2069 2070 CBS_init(&cbs, s->init_msg, s->init_num); 2071 2072 if (!CBS_get_u24_length_prefixed(&cbs, &cert_list)) 2073 goto decode_err; 2074 if (CBS_len(&cbs) != 0) 2075 goto decode_err; 2076 2077 /* 2078 * A TLS client must send an empty certificate list, if no suitable 2079 * certificate is available (rather than omitting the Certificate 2080 * handshake message) - see RFC 5246 section 7.4.6. 2081 */ 2082 if (CBS_len(&cert_list) == 0) { 2083 if ((s->verify_mode & SSL_VERIFY_PEER) && 2084 (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) { 2085 SSLerror(s, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE); 2086 al = SSL_AD_HANDSHAKE_FAILURE; 2087 goto fatal_err; 2088 } 2089 /* No client certificate so free transcript. */ 2090 tls1_transcript_free(s); 2091 goto done; 2092 } 2093 2094 if ((certs = sk_X509_new_null()) == NULL) { 2095 SSLerror(s, ERR_R_MALLOC_FAILURE); 2096 goto err; 2097 } 2098 2099 while (CBS_len(&cert_list) > 0) { 2100 if (!CBS_get_u24_length_prefixed(&cert_list, &cert_data)) 2101 goto decode_err; 2102 p = CBS_data(&cert_data); 2103 if ((cert = d2i_X509(NULL, &p, CBS_len(&cert_data))) == NULL) { 2104 SSLerror(s, ERR_R_ASN1_LIB); 2105 goto err; 2106 } 2107 if (p != CBS_data(&cert_data) + CBS_len(&cert_data)) 2108 goto decode_err; 2109 if (!sk_X509_push(certs, cert)) { 2110 SSLerror(s, ERR_R_MALLOC_FAILURE); 2111 goto err; 2112 } 2113 cert = NULL; 2114 } 2115 2116 if (ssl_verify_cert_chain(s, certs) <= 0) { 2117 al = ssl_verify_alarm_type(s->verify_result); 2118 SSLerror(s, SSL_R_NO_CERTIFICATE_RETURNED); 2119 goto fatal_err; 2120 } 2121 s->session->verify_result = s->verify_result; 2122 ERR_clear_error(); 2123 2124 if (!tls_process_peer_certs(s, certs)) 2125 goto err; 2126 2127 done: 2128 ret = 1; 2129 if (0) { 2130 decode_err: 2131 al = SSL_AD_DECODE_ERROR; 2132 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 2133 fatal_err: 2134 ssl3_send_alert(s, SSL3_AL_FATAL, al); 2135 } 2136 err: 2137 sk_X509_pop_free(certs, X509_free); 2138 X509_free(cert); 2139 2140 return (ret); 2141 } 2142 2143 static int 2144 ssl3_send_server_certificate(SSL *s) 2145 { 2146 CBB cbb, server_cert; 2147 SSL_CERT_PKEY *cpk; 2148 2149 /* 2150 * Server Certificate - RFC 5246, section 7.4.2. 2151 */ 2152 2153 memset(&cbb, 0, sizeof(cbb)); 2154 2155 if (s->s3->hs.state == SSL3_ST_SW_CERT_A) { 2156 if ((cpk = ssl_get_server_send_pkey(s)) == NULL) { 2157 SSLerror(s, ERR_R_INTERNAL_ERROR); 2158 return (0); 2159 } 2160 2161 if (!ssl3_handshake_msg_start(s, &cbb, &server_cert, 2162 SSL3_MT_CERTIFICATE)) 2163 goto err; 2164 if (!ssl3_output_cert_chain(s, &server_cert, cpk)) 2165 goto err; 2166 if (!ssl3_handshake_msg_finish(s, &cbb)) 2167 goto err; 2168 2169 s->s3->hs.state = SSL3_ST_SW_CERT_B; 2170 } 2171 2172 /* SSL3_ST_SW_CERT_B */ 2173 return (ssl3_handshake_write(s)); 2174 2175 err: 2176 CBB_cleanup(&cbb); 2177 2178 return (0); 2179 } 2180 2181 /* send a new session ticket (not necessarily for a new session) */ 2182 static int 2183 ssl3_send_newsession_ticket(SSL *s) 2184 { 2185 CBB cbb, session_ticket, ticket; 2186 SSL_CTX *tctx = s->initial_ctx; 2187 size_t enc_session_len, enc_session_max_len, hmac_len; 2188 size_t session_len = 0; 2189 unsigned char *enc_session = NULL, *session = NULL; 2190 unsigned char iv[EVP_MAX_IV_LENGTH]; 2191 unsigned char key_name[16]; 2192 unsigned char *hmac; 2193 unsigned int hlen; 2194 EVP_CIPHER_CTX *ctx = NULL; 2195 HMAC_CTX *hctx = NULL; 2196 int iv_len, len; 2197 2198 /* 2199 * New Session Ticket - RFC 5077, section 3.3. 2200 */ 2201 2202 memset(&cbb, 0, sizeof(cbb)); 2203 2204 if ((ctx = EVP_CIPHER_CTX_new()) == NULL) 2205 goto err; 2206 if ((hctx = HMAC_CTX_new()) == NULL) 2207 goto err; 2208 2209 if (s->s3->hs.state == SSL3_ST_SW_SESSION_TICKET_A) { 2210 if (!ssl3_handshake_msg_start(s, &cbb, &session_ticket, 2211 SSL3_MT_NEWSESSION_TICKET)) 2212 goto err; 2213 2214 if (!SSL_SESSION_ticket(s->session, &session, &session_len)) 2215 goto err; 2216 if (session_len > 0xffff) 2217 goto err; 2218 2219 /* 2220 * Initialize HMAC and cipher contexts. If callback is present 2221 * it does all the work, otherwise use generated values from 2222 * parent context. 2223 */ 2224 if (tctx->tlsext_ticket_key_cb != NULL) { 2225 if (tctx->tlsext_ticket_key_cb(s, 2226 key_name, iv, ctx, hctx, 1) < 0) 2227 goto err; 2228 } else { 2229 arc4random_buf(iv, 16); 2230 EVP_EncryptInit_ex(ctx, EVP_aes_128_cbc(), NULL, 2231 tctx->tlsext_tick_aes_key, iv); 2232 HMAC_Init_ex(hctx, tctx->tlsext_tick_hmac_key, 2233 16, EVP_sha256(), NULL); 2234 memcpy(key_name, tctx->tlsext_tick_key_name, 16); 2235 } 2236 2237 /* Encrypt the session state. */ 2238 enc_session_max_len = session_len + EVP_MAX_BLOCK_LENGTH; 2239 if ((enc_session = calloc(1, enc_session_max_len)) == NULL) 2240 goto err; 2241 enc_session_len = 0; 2242 if (!EVP_EncryptUpdate(ctx, enc_session, &len, session, 2243 session_len)) 2244 goto err; 2245 enc_session_len += len; 2246 if (!EVP_EncryptFinal_ex(ctx, enc_session + enc_session_len, 2247 &len)) 2248 goto err; 2249 enc_session_len += len; 2250 2251 if (enc_session_len > enc_session_max_len) 2252 goto err; 2253 2254 /* Generate the HMAC. */ 2255 if (!HMAC_Update(hctx, key_name, sizeof(key_name))) 2256 goto err; 2257 if (!HMAC_Update(hctx, iv, EVP_CIPHER_CTX_iv_length(ctx))) 2258 goto err; 2259 if (!HMAC_Update(hctx, enc_session, enc_session_len)) 2260 goto err; 2261 2262 if ((hmac_len = HMAC_size(hctx)) <= 0) 2263 goto err; 2264 2265 /* 2266 * Ticket lifetime hint (advisory only): 2267 * We leave this unspecified for resumed session 2268 * (for simplicity), and guess that tickets for new 2269 * sessions will live as long as their sessions. 2270 */ 2271 if (!CBB_add_u32(&session_ticket, 2272 s->hit ? 0 : s->session->timeout)) 2273 goto err; 2274 2275 if (!CBB_add_u16_length_prefixed(&session_ticket, &ticket)) 2276 goto err; 2277 if (!CBB_add_bytes(&ticket, key_name, sizeof(key_name))) 2278 goto err; 2279 if ((iv_len = EVP_CIPHER_CTX_iv_length(ctx)) < 0) 2280 goto err; 2281 if (!CBB_add_bytes(&ticket, iv, iv_len)) 2282 goto err; 2283 if (!CBB_add_bytes(&ticket, enc_session, enc_session_len)) 2284 goto err; 2285 if (!CBB_add_space(&ticket, &hmac, hmac_len)) 2286 goto err; 2287 2288 if (!HMAC_Final(hctx, hmac, &hlen)) 2289 goto err; 2290 if (hlen != hmac_len) 2291 goto err; 2292 2293 if (!ssl3_handshake_msg_finish(s, &cbb)) 2294 goto err; 2295 2296 s->s3->hs.state = SSL3_ST_SW_SESSION_TICKET_B; 2297 } 2298 2299 EVP_CIPHER_CTX_free(ctx); 2300 HMAC_CTX_free(hctx); 2301 freezero(session, session_len); 2302 free(enc_session); 2303 2304 /* SSL3_ST_SW_SESSION_TICKET_B */ 2305 return (ssl3_handshake_write(s)); 2306 2307 err: 2308 CBB_cleanup(&cbb); 2309 EVP_CIPHER_CTX_free(ctx); 2310 HMAC_CTX_free(hctx); 2311 freezero(session, session_len); 2312 free(enc_session); 2313 2314 return (-1); 2315 } 2316 2317 static int 2318 ssl3_send_cert_status(SSL *s) 2319 { 2320 CBB cbb, certstatus, ocspresp; 2321 2322 memset(&cbb, 0, sizeof(cbb)); 2323 2324 if (s->s3->hs.state == SSL3_ST_SW_CERT_STATUS_A) { 2325 if (!ssl3_handshake_msg_start(s, &cbb, &certstatus, 2326 SSL3_MT_CERTIFICATE_STATUS)) 2327 goto err; 2328 if (!CBB_add_u8(&certstatus, s->tlsext_status_type)) 2329 goto err; 2330 if (!CBB_add_u24_length_prefixed(&certstatus, &ocspresp)) 2331 goto err; 2332 if (!CBB_add_bytes(&ocspresp, s->tlsext_ocsp_resp, 2333 s->tlsext_ocsp_resp_len)) 2334 goto err; 2335 if (!ssl3_handshake_msg_finish(s, &cbb)) 2336 goto err; 2337 2338 s->s3->hs.state = SSL3_ST_SW_CERT_STATUS_B; 2339 } 2340 2341 /* SSL3_ST_SW_CERT_STATUS_B */ 2342 return (ssl3_handshake_write(s)); 2343 2344 err: 2345 CBB_cleanup(&cbb); 2346 2347 return (-1); 2348 } 2349 2350 static int 2351 ssl3_send_server_change_cipher_spec(SSL *s) 2352 { 2353 size_t outlen; 2354 CBB cbb; 2355 2356 memset(&cbb, 0, sizeof(cbb)); 2357 2358 if (s->s3->hs.state == SSL3_ST_SW_CHANGE_A) { 2359 if (!CBB_init_fixed(&cbb, s->init_buf->data, 2360 s->init_buf->length)) 2361 goto err; 2362 if (!CBB_add_u8(&cbb, SSL3_MT_CCS)) 2363 goto err; 2364 if (!CBB_finish(&cbb, NULL, &outlen)) 2365 goto err; 2366 2367 if (outlen > INT_MAX) 2368 goto err; 2369 2370 s->init_num = (int)outlen; 2371 s->init_off = 0; 2372 2373 if (SSL_is_dtls(s)) { 2374 s->d1->handshake_write_seq = 2375 s->d1->next_handshake_write_seq; 2376 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 2377 s->d1->handshake_write_seq, 0, 0); 2378 dtls1_buffer_message(s, 1); 2379 } 2380 2381 s->s3->hs.state = SSL3_ST_SW_CHANGE_B; 2382 } 2383 2384 /* SSL3_ST_SW_CHANGE_B */ 2385 return ssl3_record_write(s, SSL3_RT_CHANGE_CIPHER_SPEC); 2386 2387 err: 2388 CBB_cleanup(&cbb); 2389 2390 return -1; 2391 } 2392 2393 static int 2394 ssl3_get_client_finished(SSL *s) 2395 { 2396 int al, md_len, ret; 2397 CBS cbs; 2398 2399 /* should actually be 36+4 :-) */ 2400 if ((ret = ssl3_get_message(s, SSL3_ST_SR_FINISHED_A, 2401 SSL3_ST_SR_FINISHED_B, SSL3_MT_FINISHED, 64)) <= 0) 2402 return ret; 2403 2404 /* If this occurs, we have missed a message */ 2405 if (!s->s3->change_cipher_spec) { 2406 al = SSL_AD_UNEXPECTED_MESSAGE; 2407 SSLerror(s, SSL_R_GOT_A_FIN_BEFORE_A_CCS); 2408 goto fatal_err; 2409 } 2410 s->s3->change_cipher_spec = 0; 2411 2412 md_len = TLS1_FINISH_MAC_LENGTH; 2413 2414 if (s->init_num < 0) { 2415 al = SSL_AD_DECODE_ERROR; 2416 SSLerror(s, SSL_R_BAD_DIGEST_LENGTH); 2417 goto fatal_err; 2418 } 2419 2420 CBS_init(&cbs, s->init_msg, s->init_num); 2421 2422 if (s->s3->hs.peer_finished_len != md_len || 2423 CBS_len(&cbs) != md_len) { 2424 al = SSL_AD_DECODE_ERROR; 2425 SSLerror(s, SSL_R_BAD_DIGEST_LENGTH); 2426 goto fatal_err; 2427 } 2428 2429 if (!CBS_mem_equal(&cbs, s->s3->hs.peer_finished, CBS_len(&cbs))) { 2430 al = SSL_AD_DECRYPT_ERROR; 2431 SSLerror(s, SSL_R_DIGEST_CHECK_FAILED); 2432 goto fatal_err; 2433 } 2434 2435 /* Copy finished so we can use it for renegotiation checks. */ 2436 OPENSSL_assert(md_len <= EVP_MAX_MD_SIZE); 2437 memcpy(s->s3->previous_client_finished, 2438 s->s3->hs.peer_finished, md_len); 2439 s->s3->previous_client_finished_len = md_len; 2440 2441 return (1); 2442 fatal_err: 2443 ssl3_send_alert(s, SSL3_AL_FATAL, al); 2444 return (0); 2445 } 2446 2447 static int 2448 ssl3_send_server_finished(SSL *s) 2449 { 2450 CBB cbb, finished; 2451 2452 memset(&cbb, 0, sizeof(cbb)); 2453 2454 if (s->s3->hs.state == SSL3_ST_SW_FINISHED_A) { 2455 if (!tls12_derive_finished(s)) 2456 goto err; 2457 2458 /* Copy finished so we can use it for renegotiation checks. */ 2459 memcpy(s->s3->previous_server_finished, 2460 s->s3->hs.finished, s->s3->hs.finished_len); 2461 s->s3->previous_server_finished_len = s->s3->hs.finished_len; 2462 2463 if (!ssl3_handshake_msg_start(s, &cbb, &finished, 2464 SSL3_MT_FINISHED)) 2465 goto err; 2466 if (!CBB_add_bytes(&finished, s->s3->hs.finished, 2467 s->s3->hs.finished_len)) 2468 goto err; 2469 if (!ssl3_handshake_msg_finish(s, &cbb)) 2470 goto err; 2471 2472 s->s3->hs.state = SSL3_ST_SW_FINISHED_B; 2473 } 2474 2475 return (ssl3_handshake_write(s)); 2476 2477 err: 2478 CBB_cleanup(&cbb); 2479 2480 return (-1); 2481 } 2482