1 /* $OpenBSD: ssl_srvr.c,v 1.165 2024/07/22 14:47:15 jsing Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58 /* ====================================================================
59 * Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
60 *
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
63 * are met:
64 *
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
67 *
68 * 2. Redistributions in binary form must reproduce the above copyright
69 * notice, this list of conditions and the following disclaimer in
70 * the documentation and/or other materials provided with the
71 * distribution.
72 *
73 * 3. All advertising materials mentioning features or use of this
74 * software must display the following acknowledgment:
75 * "This product includes software developed by the OpenSSL Project
76 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77 *
78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79 * endorse or promote products derived from this software without
80 * prior written permission. For written permission, please contact
81 * openssl-core@openssl.org.
82 *
83 * 5. Products derived from this software may not be called "OpenSSL"
84 * nor may "OpenSSL" appear in their names without prior written
85 * permission of the OpenSSL Project.
86 *
87 * 6. Redistributions of any form whatsoever must retain the following
88 * acknowledgment:
89 * "This product includes software developed by the OpenSSL Project
90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91 *
92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103 * OF THE POSSIBILITY OF SUCH DAMAGE.
104 * ====================================================================
105 *
106 * This product includes cryptographic software written by Eric Young
107 * (eay@cryptsoft.com). This product includes software written by Tim
108 * Hudson (tjh@cryptsoft.com).
109 *
110 */
111 /* ====================================================================
112 * 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 "crypto_internal.h"
167 #include "dtls_local.h"
168 #include "ssl_local.h"
169 #include "ssl_sigalgs.h"
170 #include "ssl_tlsext.h"
171
172 static int ssl3_get_client_hello(SSL *s);
173 static int ssl3_send_dtls_hello_verify_request(SSL *s);
174 static int ssl3_send_server_hello(SSL *s);
175 static int ssl3_send_hello_request(SSL *s);
176 static int ssl3_send_server_certificate(SSL *s);
177 static int ssl3_send_server_key_exchange(SSL *s);
178 static int ssl3_send_certificate_request(SSL *s);
179 static int ssl3_send_server_done(SSL *s);
180 static int ssl3_get_client_certificate(SSL *s);
181 static int ssl3_get_client_key_exchange(SSL *s);
182 static int ssl3_get_cert_verify(SSL *s);
183 static int ssl3_send_newsession_ticket(SSL *s);
184 static int ssl3_send_cert_status(SSL *s);
185 static int ssl3_send_server_change_cipher_spec(SSL *s);
186 static int ssl3_send_server_finished(SSL *s);
187 static int ssl3_get_client_finished(SSL *s);
188
189 int
ssl3_accept(SSL * s)190 ssl3_accept(SSL *s)
191 {
192 unsigned long alg_k;
193 int new_state, state, skip = 0;
194 int listen = 0;
195 int ret = -1;
196
197 ERR_clear_error();
198 errno = 0;
199
200 if (SSL_is_dtls(s))
201 listen = s->d1->listen;
202
203 /* init things to blank */
204 s->in_handshake++;
205 if (!SSL_in_init(s) || SSL_in_before(s))
206 SSL_clear(s);
207
208 if (SSL_is_dtls(s))
209 s->d1->listen = listen;
210
211 for (;;) {
212 state = s->s3->hs.state;
213
214 switch (s->s3->hs.state) {
215 case SSL_ST_RENEGOTIATE:
216 s->renegotiate = 1;
217 /* s->s3->hs.state=SSL_ST_ACCEPT; */
218
219 case SSL_ST_BEFORE:
220 case SSL_ST_ACCEPT:
221 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
222 case SSL_ST_OK|SSL_ST_ACCEPT:
223 s->server = 1;
224
225 ssl_info_callback(s, SSL_CB_HANDSHAKE_START, 1);
226
227 if (!ssl_legacy_stack_version(s, s->version)) {
228 SSLerror(s, ERR_R_INTERNAL_ERROR);
229 ret = -1;
230 goto end;
231 }
232
233 if (!ssl_supported_tls_version_range(s,
234 &s->s3->hs.our_min_tls_version,
235 &s->s3->hs.our_max_tls_version)) {
236 SSLerror(s, SSL_R_NO_PROTOCOLS_AVAILABLE);
237 ret = -1;
238 goto end;
239 }
240
241 if (!ssl_security_version(s,
242 s->s3->hs.our_min_tls_version)) {
243 SSLerror(s, SSL_R_VERSION_TOO_LOW);
244 ret = -1;
245 goto end;
246 }
247
248 if (!ssl3_setup_init_buffer(s)) {
249 ret = -1;
250 goto end;
251 }
252 if (!ssl3_setup_buffers(s)) {
253 ret = -1;
254 goto end;
255 }
256
257 s->init_num = 0;
258
259 if (s->s3->hs.state != SSL_ST_RENEGOTIATE) {
260 /*
261 * Ok, we now need to push on a buffering BIO
262 * so that the output is sent in a way that
263 * TCP likes :-)
264 */
265 if (!ssl_init_wbio_buffer(s, 1)) {
266 ret = -1;
267 goto end;
268 }
269
270 if (!tls1_transcript_init(s)) {
271 ret = -1;
272 goto end;
273 }
274
275 s->s3->hs.state = SSL3_ST_SR_CLNT_HELLO_A;
276 s->ctx->stats.sess_accept++;
277 } else if (!SSL_is_dtls(s) && !s->s3->send_connection_binding) {
278 /*
279 * Server attempting to renegotiate with
280 * client that doesn't support secure
281 * renegotiation.
282 */
283 SSLerror(s, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
284 ssl3_send_alert(s, SSL3_AL_FATAL,
285 SSL_AD_HANDSHAKE_FAILURE);
286 ret = -1;
287 goto end;
288 } else {
289 /*
290 * s->s3->hs.state == SSL_ST_RENEGOTIATE,
291 * we will just send a HelloRequest.
292 */
293 s->ctx->stats.sess_accept_renegotiate++;
294 s->s3->hs.state = SSL3_ST_SW_HELLO_REQ_A;
295 }
296 break;
297
298 case SSL3_ST_SW_HELLO_REQ_A:
299 case SSL3_ST_SW_HELLO_REQ_B:
300 s->shutdown = 0;
301 if (SSL_is_dtls(s)) {
302 dtls1_clear_record_buffer(s);
303 dtls1_start_timer(s);
304 }
305 ret = ssl3_send_hello_request(s);
306 if (ret <= 0)
307 goto end;
308 if (SSL_is_dtls(s))
309 s->s3->hs.tls12.next_state = SSL3_ST_SR_CLNT_HELLO_A;
310 else
311 s->s3->hs.tls12.next_state = SSL3_ST_SW_HELLO_REQ_C;
312 s->s3->hs.state = SSL3_ST_SW_FLUSH;
313 s->init_num = 0;
314
315 if (SSL_is_dtls(s)) {
316 if (!tls1_transcript_init(s)) {
317 ret = -1;
318 goto end;
319 }
320 }
321 break;
322
323 case SSL3_ST_SW_HELLO_REQ_C:
324 s->s3->hs.state = SSL_ST_OK;
325 break;
326
327 case SSL3_ST_SR_CLNT_HELLO_A:
328 case SSL3_ST_SR_CLNT_HELLO_B:
329 case SSL3_ST_SR_CLNT_HELLO_C:
330 s->shutdown = 0;
331 if (SSL_is_dtls(s)) {
332 ret = ssl3_get_client_hello(s);
333 if (ret <= 0)
334 goto end;
335 dtls1_stop_timer(s);
336
337 if (ret == 1 &&
338 (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
339 s->s3->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
340 else
341 s->s3->hs.state = SSL3_ST_SW_SRVR_HELLO_A;
342
343 s->init_num = 0;
344
345 /*
346 * Reflect ClientHello sequence to remain
347 * stateless while listening.
348 */
349 if (listen) {
350 tls12_record_layer_reflect_seq_num(
351 s->rl);
352 }
353
354 /* If we're just listening, stop here */
355 if (listen && s->s3->hs.state == SSL3_ST_SW_SRVR_HELLO_A) {
356 ret = 2;
357 s->d1->listen = 0;
358 /*
359 * Set expected sequence numbers to
360 * continue the handshake.
361 */
362 s->d1->handshake_read_seq = 2;
363 s->d1->handshake_write_seq = 1;
364 s->d1->next_handshake_write_seq = 1;
365 goto end;
366 }
367 } else {
368 if (s->rwstate != SSL_X509_LOOKUP) {
369 ret = ssl3_get_client_hello(s);
370 if (ret <= 0)
371 goto end;
372 }
373
374 s->renegotiate = 2;
375 s->s3->hs.state = SSL3_ST_SW_SRVR_HELLO_A;
376 s->init_num = 0;
377 }
378 break;
379
380 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
381 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
382 ret = ssl3_send_dtls_hello_verify_request(s);
383 if (ret <= 0)
384 goto end;
385 s->s3->hs.state = SSL3_ST_SW_FLUSH;
386 s->s3->hs.tls12.next_state = SSL3_ST_SR_CLNT_HELLO_A;
387
388 /* HelloVerifyRequest resets Finished MAC. */
389 tls1_transcript_reset(s);
390 break;
391
392 case SSL3_ST_SW_SRVR_HELLO_A:
393 case SSL3_ST_SW_SRVR_HELLO_B:
394 if (SSL_is_dtls(s)) {
395 s->renegotiate = 2;
396 dtls1_start_timer(s);
397 }
398 ret = ssl3_send_server_hello(s);
399 if (ret <= 0)
400 goto end;
401 if (s->hit) {
402 if (s->tlsext_ticket_expected)
403 s->s3->hs.state = SSL3_ST_SW_SESSION_TICKET_A;
404 else
405 s->s3->hs.state = SSL3_ST_SW_CHANGE_A;
406 } else {
407 s->s3->hs.state = SSL3_ST_SW_CERT_A;
408 }
409 s->init_num = 0;
410 break;
411
412 case SSL3_ST_SW_CERT_A:
413 case SSL3_ST_SW_CERT_B:
414 /* Check if it is anon DH or anon ECDH. */
415 if (!(s->s3->hs.cipher->algorithm_auth &
416 SSL_aNULL)) {
417 if (SSL_is_dtls(s))
418 dtls1_start_timer(s);
419 ret = ssl3_send_server_certificate(s);
420 if (ret <= 0)
421 goto end;
422 if (s->tlsext_status_expected)
423 s->s3->hs.state = SSL3_ST_SW_CERT_STATUS_A;
424 else
425 s->s3->hs.state = SSL3_ST_SW_KEY_EXCH_A;
426 } else {
427 skip = 1;
428 s->s3->hs.state = SSL3_ST_SW_KEY_EXCH_A;
429 }
430 s->init_num = 0;
431 break;
432
433 case SSL3_ST_SW_KEY_EXCH_A:
434 case SSL3_ST_SW_KEY_EXCH_B:
435 alg_k = s->s3->hs.cipher->algorithm_mkey;
436
437 /*
438 * Only send if using a DH key exchange.
439 *
440 * For ECC ciphersuites, we send a ServerKeyExchange
441 * message only if the cipher suite is ECDHE. In other
442 * cases, the server certificate contains the server's
443 * public key for key exchange.
444 */
445 if (alg_k & (SSL_kDHE|SSL_kECDHE)) {
446 if (SSL_is_dtls(s))
447 dtls1_start_timer(s);
448 ret = ssl3_send_server_key_exchange(s);
449 if (ret <= 0)
450 goto end;
451 } else
452 skip = 1;
453
454 s->s3->hs.state = SSL3_ST_SW_CERT_REQ_A;
455 s->init_num = 0;
456 break;
457
458 case SSL3_ST_SW_CERT_REQ_A:
459 case SSL3_ST_SW_CERT_REQ_B:
460 /*
461 * Determine whether or not we need to request a
462 * certificate.
463 *
464 * Do not request a certificate if:
465 *
466 * - We did not ask for it (SSL_VERIFY_PEER is unset).
467 *
468 * - SSL_VERIFY_CLIENT_ONCE is set and we are
469 * renegotiating.
470 *
471 * - We are using an anonymous ciphersuites
472 * (see section "Certificate request" in SSL 3 drafts
473 * and in RFC 2246) ... except when the application
474 * insists on verification (against the specs, but
475 * s3_clnt.c accepts this for SSL 3).
476 */
477 if (!(s->verify_mode & SSL_VERIFY_PEER) ||
478 ((s->session->peer_cert != NULL) &&
479 (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
480 ((s->s3->hs.cipher->algorithm_auth &
481 SSL_aNULL) && !(s->verify_mode &
482 SSL_VERIFY_FAIL_IF_NO_PEER_CERT))) {
483 /* No cert request. */
484 skip = 1;
485 s->s3->hs.tls12.cert_request = 0;
486 s->s3->hs.state = SSL3_ST_SW_SRVR_DONE_A;
487
488 if (!SSL_is_dtls(s))
489 tls1_transcript_free(s);
490 } else {
491 s->s3->hs.tls12.cert_request = 1;
492 if (SSL_is_dtls(s))
493 dtls1_start_timer(s);
494 ret = ssl3_send_certificate_request(s);
495 if (ret <= 0)
496 goto end;
497 s->s3->hs.state = SSL3_ST_SW_SRVR_DONE_A;
498 s->init_num = 0;
499 }
500 break;
501
502 case SSL3_ST_SW_SRVR_DONE_A:
503 case SSL3_ST_SW_SRVR_DONE_B:
504 if (SSL_is_dtls(s))
505 dtls1_start_timer(s);
506 ret = ssl3_send_server_done(s);
507 if (ret <= 0)
508 goto end;
509 s->s3->hs.tls12.next_state = SSL3_ST_SR_CERT_A;
510 s->s3->hs.state = SSL3_ST_SW_FLUSH;
511 s->init_num = 0;
512 break;
513
514 case SSL3_ST_SW_FLUSH:
515 /*
516 * This code originally checked to see if
517 * any data was pending using BIO_CTRL_INFO
518 * and then flushed. This caused problems
519 * as documented in PR#1939. The proposed
520 * fix doesn't completely resolve this issue
521 * as buggy implementations of BIO_CTRL_PENDING
522 * still exist. So instead we just flush
523 * unconditionally.
524 */
525 s->rwstate = SSL_WRITING;
526 if (BIO_flush(s->wbio) <= 0) {
527 if (SSL_is_dtls(s)) {
528 /* If the write error was fatal, stop trying. */
529 if (!BIO_should_retry(s->wbio)) {
530 s->rwstate = SSL_NOTHING;
531 s->s3->hs.state = s->s3->hs.tls12.next_state;
532 }
533 }
534 ret = -1;
535 goto end;
536 }
537 s->rwstate = SSL_NOTHING;
538 s->s3->hs.state = s->s3->hs.tls12.next_state;
539 break;
540
541 case SSL3_ST_SR_CERT_A:
542 case SSL3_ST_SR_CERT_B:
543 if (s->s3->hs.tls12.cert_request != 0) {
544 ret = ssl3_get_client_certificate(s);
545 if (ret <= 0)
546 goto end;
547 }
548 s->init_num = 0;
549 s->s3->hs.state = SSL3_ST_SR_KEY_EXCH_A;
550 break;
551
552 case SSL3_ST_SR_KEY_EXCH_A:
553 case SSL3_ST_SR_KEY_EXCH_B:
554 ret = ssl3_get_client_key_exchange(s);
555 if (ret <= 0)
556 goto end;
557
558 if (SSL_is_dtls(s)) {
559 s->s3->hs.state = SSL3_ST_SR_CERT_VRFY_A;
560 s->init_num = 0;
561 }
562
563 alg_k = s->s3->hs.cipher->algorithm_mkey;
564 if (SSL_USE_SIGALGS(s)) {
565 s->s3->hs.state = SSL3_ST_SR_CERT_VRFY_A;
566 s->init_num = 0;
567 if (!s->session->peer_cert)
568 break;
569 /*
570 * Freeze the transcript for use during client
571 * certificate verification.
572 */
573 tls1_transcript_freeze(s);
574 } else {
575 s->s3->hs.state = SSL3_ST_SR_CERT_VRFY_A;
576 s->init_num = 0;
577
578 tls1_transcript_free(s);
579
580 /*
581 * We need to get hashes here so if there is
582 * a client cert, it can be verified.
583 */
584 if (!tls1_transcript_hash_value(s,
585 s->s3->hs.tls12.cert_verify,
586 sizeof(s->s3->hs.tls12.cert_verify),
587 NULL)) {
588 ret = -1;
589 goto end;
590 }
591 }
592 break;
593
594 case SSL3_ST_SR_CERT_VRFY_A:
595 case SSL3_ST_SR_CERT_VRFY_B:
596 if (SSL_is_dtls(s))
597 s->d1->change_cipher_spec_ok = 1;
598 else
599 s->s3->flags |= SSL3_FLAGS_CCS_OK;
600
601 /* we should decide if we expected this one */
602 ret = ssl3_get_cert_verify(s);
603 if (ret <= 0)
604 goto end;
605 s->s3->hs.state = SSL3_ST_SR_FINISHED_A;
606 s->init_num = 0;
607 break;
608
609 case SSL3_ST_SR_FINISHED_A:
610 case SSL3_ST_SR_FINISHED_B:
611 if (SSL_is_dtls(s))
612 s->d1->change_cipher_spec_ok = 1;
613 else
614 s->s3->flags |= SSL3_FLAGS_CCS_OK;
615 ret = ssl3_get_client_finished(s);
616 if (ret <= 0)
617 goto end;
618 if (SSL_is_dtls(s))
619 dtls1_stop_timer(s);
620 if (s->hit)
621 s->s3->hs.state = SSL_ST_OK;
622 else if (s->tlsext_ticket_expected)
623 s->s3->hs.state = SSL3_ST_SW_SESSION_TICKET_A;
624 else
625 s->s3->hs.state = SSL3_ST_SW_CHANGE_A;
626 s->init_num = 0;
627 break;
628
629 case SSL3_ST_SW_SESSION_TICKET_A:
630 case SSL3_ST_SW_SESSION_TICKET_B:
631 ret = ssl3_send_newsession_ticket(s);
632 if (ret <= 0)
633 goto end;
634 s->s3->hs.state = SSL3_ST_SW_CHANGE_A;
635 s->init_num = 0;
636 break;
637
638 case SSL3_ST_SW_CERT_STATUS_A:
639 case SSL3_ST_SW_CERT_STATUS_B:
640 ret = ssl3_send_cert_status(s);
641 if (ret <= 0)
642 goto end;
643 s->s3->hs.state = SSL3_ST_SW_KEY_EXCH_A;
644 s->init_num = 0;
645 break;
646
647 case SSL3_ST_SW_CHANGE_A:
648 case SSL3_ST_SW_CHANGE_B:
649 ret = ssl3_send_server_change_cipher_spec(s);
650 if (ret <= 0)
651 goto end;
652 s->s3->hs.state = SSL3_ST_SW_FINISHED_A;
653 s->init_num = 0;
654 s->session->cipher_value = s->s3->hs.cipher->value;
655
656 if (!tls1_setup_key_block(s)) {
657 ret = -1;
658 goto end;
659 }
660 if (!tls1_change_write_cipher_state(s)) {
661 ret = -1;
662 goto end;
663 }
664 break;
665
666 case SSL3_ST_SW_FINISHED_A:
667 case SSL3_ST_SW_FINISHED_B:
668 ret = ssl3_send_server_finished(s);
669 if (ret <= 0)
670 goto end;
671 s->s3->hs.state = SSL3_ST_SW_FLUSH;
672 if (s->hit) {
673 s->s3->hs.tls12.next_state = SSL3_ST_SR_FINISHED_A;
674 tls1_transcript_free(s);
675 } else
676 s->s3->hs.tls12.next_state = SSL_ST_OK;
677 s->init_num = 0;
678 break;
679
680 case SSL_ST_OK:
681 /* clean a few things up */
682 tls1_cleanup_key_block(s);
683
684 if (s->s3->handshake_transcript != NULL) {
685 SSLerror(s, ERR_R_INTERNAL_ERROR);
686 ret = -1;
687 goto end;
688 }
689
690 if (!SSL_is_dtls(s))
691 ssl3_release_init_buffer(s);
692
693 /* remove buffering on output */
694 ssl_free_wbio_buffer(s);
695
696 s->init_num = 0;
697
698 /* Skipped if we just sent a HelloRequest. */
699 if (s->renegotiate == 2) {
700 s->renegotiate = 0;
701 s->new_session = 0;
702
703 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
704
705 s->ctx->stats.sess_accept_good++;
706 /* s->server=1; */
707 s->handshake_func = ssl3_accept;
708
709 ssl_info_callback(s, SSL_CB_HANDSHAKE_DONE, 1);
710 }
711
712 ret = 1;
713
714 if (SSL_is_dtls(s)) {
715 /* Done handshaking, next message is client hello. */
716 s->d1->handshake_read_seq = 0;
717 /* Next message is server hello. */
718 s->d1->handshake_write_seq = 0;
719 s->d1->next_handshake_write_seq = 0;
720 }
721 goto end;
722 /* break; */
723
724 default:
725 SSLerror(s, SSL_R_UNKNOWN_STATE);
726 ret = -1;
727 goto end;
728 /* break; */
729 }
730
731 if (!s->s3->hs.tls12.reuse_message && !skip) {
732 if (s->s3->hs.state != state) {
733 new_state = s->s3->hs.state;
734 s->s3->hs.state = state;
735 ssl_info_callback(s, SSL_CB_ACCEPT_LOOP, 1);
736 s->s3->hs.state = new_state;
737 }
738 }
739 skip = 0;
740 }
741 end:
742 /* BIO_flush(s->wbio); */
743 s->in_handshake--;
744 ssl_info_callback(s, SSL_CB_ACCEPT_EXIT, ret);
745
746 return (ret);
747 }
748
749 static int
ssl3_send_hello_request(SSL * s)750 ssl3_send_hello_request(SSL *s)
751 {
752 CBB cbb, hello;
753
754 memset(&cbb, 0, sizeof(cbb));
755
756 if (s->s3->hs.state == SSL3_ST_SW_HELLO_REQ_A) {
757 if (!ssl3_handshake_msg_start(s, &cbb, &hello,
758 SSL3_MT_HELLO_REQUEST))
759 goto err;
760 if (!ssl3_handshake_msg_finish(s, &cbb))
761 goto err;
762
763 s->s3->hs.state = SSL3_ST_SW_HELLO_REQ_B;
764 }
765
766 /* SSL3_ST_SW_HELLO_REQ_B */
767 return (ssl3_handshake_write(s));
768
769 err:
770 CBB_cleanup(&cbb);
771
772 return (-1);
773 }
774
775 static int
ssl3_get_client_hello(SSL * s)776 ssl3_get_client_hello(SSL *s)
777 {
778 CBS cbs, client_random, session_id, cookie, cipher_suites;
779 CBS compression_methods;
780 uint16_t client_version;
781 uint8_t comp_method;
782 int comp_null;
783 int i, j, al, ret, cookie_valid = 0;
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
981 for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
982 c = sk_SSL_CIPHER_value(ciphers, i);
983 if (c->value == s->session->cipher_value) {
984 j = 1;
985 break;
986 }
987 }
988 if (j == 0) {
989 /*
990 * We need to have the cipher in the cipher
991 * list if we are asked to reuse it
992 */
993 al = SSL_AD_ILLEGAL_PARAMETER;
994 SSLerror(s, SSL_R_REQUIRED_CIPHER_MISSING);
995 goto fatal_err;
996 }
997 }
998
999 comp_null = 0;
1000 while (CBS_len(&compression_methods) > 0) {
1001 if (!CBS_get_u8(&compression_methods, &comp_method))
1002 goto decode_err;
1003 if (comp_method == 0)
1004 comp_null = 1;
1005 }
1006 if (comp_null == 0) {
1007 al = SSL_AD_DECODE_ERROR;
1008 SSLerror(s, SSL_R_NO_COMPRESSION_SPECIFIED);
1009 goto fatal_err;
1010 }
1011
1012 if (!tlsext_server_parse(s, SSL_TLSEXT_MSG_CH, &cbs, &al)) {
1013 SSLerror(s, SSL_R_PARSE_TLSEXT);
1014 goto fatal_err;
1015 }
1016
1017 if (CBS_len(&cbs) != 0)
1018 goto decode_err;
1019
1020 if (!s->s3->renegotiate_seen && s->renegotiate) {
1021 al = SSL_AD_HANDSHAKE_FAILURE;
1022 SSLerror(s, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
1023 goto fatal_err;
1024 }
1025
1026 if (ssl_check_clienthello_tlsext_early(s) <= 0) {
1027 SSLerror(s, SSL_R_CLIENTHELLO_TLSEXT);
1028 goto err;
1029 }
1030
1031 /*
1032 * Check if we want to use external pre-shared secret for this
1033 * handshake for not reused session only. We need to generate
1034 * server_random before calling tls_session_secret_cb in order to allow
1035 * SessionTicket processing to use it in key derivation.
1036 */
1037 arc4random_buf(s->s3->server_random, SSL3_RANDOM_SIZE);
1038
1039 if (s->s3->hs.our_max_tls_version >= TLS1_2_VERSION &&
1040 s->s3->hs.negotiated_tls_version < s->s3->hs.our_max_tls_version) {
1041 /*
1042 * RFC 8446 section 4.1.3. If we are downgrading from TLS 1.3
1043 * we must set the last 8 bytes of the server random to magical
1044 * values to indicate we meant to downgrade. For TLS 1.2 it is
1045 * recommended that we do the same.
1046 */
1047 size_t index = SSL3_RANDOM_SIZE - sizeof(tls13_downgrade_12);
1048 uint8_t *magic = &s->s3->server_random[index];
1049 if (s->s3->hs.negotiated_tls_version == TLS1_2_VERSION) {
1050 /* Indicate we chose to downgrade to 1.2. */
1051 memcpy(magic, tls13_downgrade_12,
1052 sizeof(tls13_downgrade_12));
1053 } else {
1054 /* Indicate we chose to downgrade to 1.1 or lower */
1055 memcpy(magic, tls13_downgrade_11,
1056 sizeof(tls13_downgrade_11));
1057 }
1058 }
1059
1060 if (!s->hit && s->tls_session_secret_cb != NULL) {
1061 SSL_CIPHER *pref_cipher = NULL;
1062 int master_key_length = sizeof(s->session->master_key);
1063
1064 if (!s->tls_session_secret_cb(s,
1065 s->session->master_key, &master_key_length, ciphers,
1066 &pref_cipher, s->tls_session_secret_cb_arg)) {
1067 SSLerror(s, ERR_R_INTERNAL_ERROR);
1068 goto err;
1069 }
1070 if (master_key_length <= 0) {
1071 SSLerror(s, ERR_R_INTERNAL_ERROR);
1072 goto err;
1073 }
1074 s->session->master_key_length = master_key_length;
1075
1076 s->hit = 1;
1077 s->session->verify_result = X509_V_OK;
1078
1079 sk_SSL_CIPHER_free(s->s3->hs.client_ciphers);
1080 s->s3->hs.client_ciphers = ciphers;
1081 ciphers = NULL;
1082
1083 /*
1084 * XXX - this allows the callback to use any client cipher and
1085 * completely ignore the server cipher list. We should ensure
1086 * that the pref_cipher is in both the client list and the
1087 * server list.
1088 */
1089
1090 /* Check if some cipher was preferred by the callback. */
1091 if (pref_cipher == NULL)
1092 pref_cipher = ssl3_choose_cipher(s, s->s3->hs.client_ciphers,
1093 SSL_get_ciphers(s));
1094 if (pref_cipher == NULL) {
1095 al = SSL_AD_HANDSHAKE_FAILURE;
1096 SSLerror(s, SSL_R_NO_SHARED_CIPHER);
1097 goto fatal_err;
1098 }
1099 s->s3->hs.cipher = pref_cipher;
1100
1101 /* XXX - why? */
1102 sk_SSL_CIPHER_free(s->cipher_list);
1103 s->cipher_list = sk_SSL_CIPHER_dup(s->s3->hs.client_ciphers);
1104 }
1105
1106 /*
1107 * Given s->session->ciphers and SSL_get_ciphers, we must
1108 * pick a cipher
1109 */
1110
1111 if (!s->hit) {
1112 if (ciphers == NULL) {
1113 al = SSL_AD_ILLEGAL_PARAMETER;
1114 SSLerror(s, SSL_R_NO_CIPHERS_PASSED);
1115 goto fatal_err;
1116 }
1117 sk_SSL_CIPHER_free(s->s3->hs.client_ciphers);
1118 s->s3->hs.client_ciphers = ciphers;
1119 ciphers = NULL;
1120
1121 if ((c = ssl3_choose_cipher(s, s->s3->hs.client_ciphers,
1122 SSL_get_ciphers(s))) == NULL) {
1123 al = SSL_AD_HANDSHAKE_FAILURE;
1124 SSLerror(s, SSL_R_NO_SHARED_CIPHER);
1125 goto fatal_err;
1126 }
1127 s->s3->hs.cipher = c;
1128 s->session->cipher_value = s->s3->hs.cipher->value;
1129 } else {
1130 s->s3->hs.cipher = ssl3_get_cipher_by_value(s->session->cipher_value);
1131 if (s->s3->hs.cipher == NULL)
1132 goto fatal_err;
1133 }
1134
1135 if (!tls1_transcript_hash_init(s))
1136 goto err;
1137
1138 if (!SSL_USE_SIGALGS(s) || !(s->verify_mode & SSL_VERIFY_PEER))
1139 tls1_transcript_free(s);
1140
1141 /*
1142 * We now have the following setup.
1143 * client_random
1144 * cipher_list - our preferred list of ciphers
1145 * ciphers - the clients preferred list of ciphers
1146 * compression - basically ignored right now
1147 * ssl version is set - sslv3
1148 * s->session - The ssl session has been setup.
1149 * s->hit - session reuse flag
1150 * s->hs.cipher - the new cipher to use.
1151 */
1152
1153 /* Handles TLS extensions that we couldn't check earlier */
1154 if (ssl_check_clienthello_tlsext_late(s) <= 0) {
1155 SSLerror(s, SSL_R_CLIENTHELLO_TLSEXT);
1156 goto err;
1157 }
1158
1159 ret = cookie_valid ? 2 : 1;
1160
1161 if (0) {
1162 decode_err:
1163 al = SSL_AD_DECODE_ERROR;
1164 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
1165 fatal_err:
1166 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1167 }
1168 err:
1169 sk_SSL_CIPHER_free(ciphers);
1170
1171 return (ret);
1172 }
1173
1174 static int
ssl3_send_dtls_hello_verify_request(SSL * s)1175 ssl3_send_dtls_hello_verify_request(SSL *s)
1176 {
1177 CBB cbb, verify, cookie;
1178
1179 memset(&cbb, 0, sizeof(cbb));
1180
1181 if (s->s3->hs.state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
1182 if (s->ctx->app_gen_cookie_cb == NULL ||
1183 s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
1184 &(s->d1->cookie_len)) == 0) {
1185 SSLerror(s, ERR_R_INTERNAL_ERROR);
1186 return 0;
1187 }
1188
1189 /*
1190 * Per RFC 6347 section 4.2.1, the HelloVerifyRequest should
1191 * always contain DTLSv1.0 regardless of the version that is
1192 * going to be negotiated.
1193 */
1194 if (!ssl3_handshake_msg_start(s, &cbb, &verify,
1195 DTLS1_MT_HELLO_VERIFY_REQUEST))
1196 goto err;
1197 if (!CBB_add_u16(&verify, DTLS1_VERSION))
1198 goto err;
1199 if (!CBB_add_u8_length_prefixed(&verify, &cookie))
1200 goto err;
1201 if (!CBB_add_bytes(&cookie, s->d1->cookie, s->d1->cookie_len))
1202 goto err;
1203 if (!ssl3_handshake_msg_finish(s, &cbb))
1204 goto err;
1205
1206 s->s3->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
1207 }
1208
1209 /* s->s3->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
1210 return (ssl3_handshake_write(s));
1211
1212 err:
1213 CBB_cleanup(&cbb);
1214
1215 return (-1);
1216 }
1217
1218 static int
ssl3_send_server_hello(SSL * s)1219 ssl3_send_server_hello(SSL *s)
1220 {
1221 CBB cbb, server_hello, session_id;
1222 size_t sl;
1223
1224 memset(&cbb, 0, sizeof(cbb));
1225
1226 if (s->s3->hs.state == SSL3_ST_SW_SRVR_HELLO_A) {
1227 if (!ssl3_handshake_msg_start(s, &cbb, &server_hello,
1228 SSL3_MT_SERVER_HELLO))
1229 goto err;
1230
1231 if (!CBB_add_u16(&server_hello, s->version))
1232 goto err;
1233 if (!CBB_add_bytes(&server_hello, s->s3->server_random,
1234 sizeof(s->s3->server_random)))
1235 goto err;
1236
1237 /*
1238 * There are several cases for the session ID to send
1239 * back in the server hello:
1240 *
1241 * - For session reuse from the session cache,
1242 * we send back the old session ID.
1243 * - If stateless session reuse (using a session ticket)
1244 * is successful, we send back the client's "session ID"
1245 * (which doesn't actually identify the session).
1246 * - If it is a new session, we send back the new
1247 * session ID.
1248 * - However, if we want the new session to be single-use,
1249 * we send back a 0-length session ID.
1250 *
1251 * s->hit is non-zero in either case of session reuse,
1252 * so the following won't overwrite an ID that we're supposed
1253 * to send back.
1254 */
1255 if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)
1256 && !s->hit)
1257 s->session->session_id_length = 0;
1258
1259 sl = s->session->session_id_length;
1260 if (sl > sizeof(s->session->session_id)) {
1261 SSLerror(s, ERR_R_INTERNAL_ERROR);
1262 goto err;
1263 }
1264 if (!CBB_add_u8_length_prefixed(&server_hello, &session_id))
1265 goto err;
1266 if (!CBB_add_bytes(&session_id, s->session->session_id, sl))
1267 goto err;
1268
1269 /* Cipher suite. */
1270 if (!CBB_add_u16(&server_hello, s->s3->hs.cipher->value))
1271 goto err;
1272
1273 /* Compression method (null). */
1274 if (!CBB_add_u8(&server_hello, 0))
1275 goto err;
1276
1277 /* TLS extensions */
1278 if (!tlsext_server_build(s, SSL_TLSEXT_MSG_SH, &server_hello)) {
1279 SSLerror(s, ERR_R_INTERNAL_ERROR);
1280 goto err;
1281 }
1282
1283 if (!ssl3_handshake_msg_finish(s, &cbb))
1284 goto err;
1285 }
1286
1287 /* SSL3_ST_SW_SRVR_HELLO_B */
1288 return (ssl3_handshake_write(s));
1289
1290 err:
1291 CBB_cleanup(&cbb);
1292
1293 return (-1);
1294 }
1295
1296 static int
ssl3_send_server_done(SSL * s)1297 ssl3_send_server_done(SSL *s)
1298 {
1299 CBB cbb, done;
1300
1301 memset(&cbb, 0, sizeof(cbb));
1302
1303 if (s->s3->hs.state == SSL3_ST_SW_SRVR_DONE_A) {
1304 if (!ssl3_handshake_msg_start(s, &cbb, &done,
1305 SSL3_MT_SERVER_DONE))
1306 goto err;
1307 if (!ssl3_handshake_msg_finish(s, &cbb))
1308 goto err;
1309
1310 s->s3->hs.state = SSL3_ST_SW_SRVR_DONE_B;
1311 }
1312
1313 /* SSL3_ST_SW_SRVR_DONE_B */
1314 return (ssl3_handshake_write(s));
1315
1316 err:
1317 CBB_cleanup(&cbb);
1318
1319 return (-1);
1320 }
1321
1322 static int
ssl3_send_server_kex_dhe(SSL * s,CBB * cbb)1323 ssl3_send_server_kex_dhe(SSL *s, CBB *cbb)
1324 {
1325 int nid = NID_dhKeyAgreement;
1326
1327 tls_key_share_free(s->s3->hs.key_share);
1328 if ((s->s3->hs.key_share = tls_key_share_new_nid(nid)) == NULL)
1329 goto err;
1330
1331 if (s->cert->dhe_params_auto != 0) {
1332 size_t key_bits;
1333
1334 if ((key_bits = ssl_dhe_params_auto_key_bits(s)) == 0) {
1335 SSLerror(s, ERR_R_INTERNAL_ERROR);
1336 ssl3_send_alert(s, SSL3_AL_FATAL,
1337 SSL_AD_INTERNAL_ERROR);
1338 goto err;
1339 }
1340 tls_key_share_set_key_bits(s->s3->hs.key_share,
1341 key_bits);
1342 } else {
1343 DH *dh_params = s->cert->dhe_params;
1344
1345 if (dh_params == NULL && s->cert->dhe_params_cb != NULL)
1346 dh_params = s->cert->dhe_params_cb(s, 0,
1347 SSL_C_PKEYLENGTH(s->s3->hs.cipher));
1348
1349 if (dh_params == NULL) {
1350 SSLerror(s, SSL_R_MISSING_TMP_DH_KEY);
1351 ssl3_send_alert(s, SSL3_AL_FATAL,
1352 SSL_AD_HANDSHAKE_FAILURE);
1353 goto err;
1354 }
1355
1356 if (!tls_key_share_set_dh_params(s->s3->hs.key_share, dh_params))
1357 goto err;
1358 }
1359
1360 if (!tls_key_share_generate(s->s3->hs.key_share))
1361 goto err;
1362
1363 if (!tls_key_share_params(s->s3->hs.key_share, cbb))
1364 goto err;
1365 if (!tls_key_share_public(s->s3->hs.key_share, cbb))
1366 goto err;
1367
1368 if (!tls_key_share_peer_security(s, s->s3->hs.key_share)) {
1369 SSLerror(s, SSL_R_DH_KEY_TOO_SMALL);
1370 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
1371 return 0;
1372 }
1373
1374 return 1;
1375
1376 err:
1377 return 0;
1378 }
1379
1380 static int
ssl3_send_server_kex_ecdhe(SSL * s,CBB * cbb)1381 ssl3_send_server_kex_ecdhe(SSL *s, CBB *cbb)
1382 {
1383 CBB public;
1384 int nid;
1385
1386 if (!tls1_get_supported_group(s, &nid)) {
1387 SSLerror(s, SSL_R_UNSUPPORTED_ELLIPTIC_CURVE);
1388 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
1389 goto err;
1390 }
1391
1392 tls_key_share_free(s->s3->hs.key_share);
1393 if ((s->s3->hs.key_share = tls_key_share_new_nid(nid)) == NULL)
1394 goto err;
1395
1396 if (!tls_key_share_generate(s->s3->hs.key_share))
1397 goto err;
1398
1399 /*
1400 * ECC key exchange - see RFC 8422, section 5.4.
1401 */
1402 if (!CBB_add_u8(cbb, NAMED_CURVE_TYPE))
1403 goto err;
1404 if (!CBB_add_u16(cbb, tls_key_share_group(s->s3->hs.key_share)))
1405 goto err;
1406 if (!CBB_add_u8_length_prefixed(cbb, &public))
1407 goto err;
1408 if (!tls_key_share_public(s->s3->hs.key_share, &public))
1409 goto err;
1410 if (!CBB_flush(cbb))
1411 goto err;
1412
1413 return 1;
1414
1415 err:
1416 return 0;
1417 }
1418
1419 static int
ssl3_send_server_key_exchange(SSL * s)1420 ssl3_send_server_key_exchange(SSL *s)
1421 {
1422 CBB cbb, cbb_signature, cbb_signed_params, server_kex;
1423 CBS params;
1424 const struct ssl_sigalg *sigalg = NULL;
1425 unsigned char *signed_params = NULL;
1426 size_t signed_params_len;
1427 unsigned char *signature = NULL;
1428 size_t signature_len = 0;
1429 const EVP_MD *md = NULL;
1430 unsigned long type;
1431 EVP_MD_CTX *md_ctx = NULL;
1432 EVP_PKEY_CTX *pctx;
1433 EVP_PKEY *pkey;
1434 int al;
1435
1436 memset(&cbb, 0, sizeof(cbb));
1437 memset(&cbb_signed_params, 0, sizeof(cbb_signed_params));
1438
1439 if ((md_ctx = EVP_MD_CTX_new()) == NULL)
1440 goto err;
1441
1442 if (s->s3->hs.state == SSL3_ST_SW_KEY_EXCH_A) {
1443
1444 if (!ssl3_handshake_msg_start(s, &cbb, &server_kex,
1445 SSL3_MT_SERVER_KEY_EXCHANGE))
1446 goto err;
1447
1448 if (!CBB_init(&cbb_signed_params, 0))
1449 goto err;
1450
1451 if (!CBB_add_bytes(&cbb_signed_params, s->s3->client_random,
1452 SSL3_RANDOM_SIZE)) {
1453 SSLerror(s, ERR_R_INTERNAL_ERROR);
1454 goto err;
1455 }
1456 if (!CBB_add_bytes(&cbb_signed_params, s->s3->server_random,
1457 SSL3_RANDOM_SIZE)) {
1458 SSLerror(s, ERR_R_INTERNAL_ERROR);
1459 goto err;
1460 }
1461
1462 type = s->s3->hs.cipher->algorithm_mkey;
1463 if (type & SSL_kDHE) {
1464 if (!ssl3_send_server_kex_dhe(s, &cbb_signed_params))
1465 goto err;
1466 } else if (type & SSL_kECDHE) {
1467 if (!ssl3_send_server_kex_ecdhe(s, &cbb_signed_params))
1468 goto err;
1469 } else {
1470 al = SSL_AD_HANDSHAKE_FAILURE;
1471 SSLerror(s, SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
1472 goto fatal_err;
1473 }
1474
1475 if (!CBB_finish(&cbb_signed_params, &signed_params,
1476 &signed_params_len))
1477 goto err;
1478
1479 CBS_init(¶ms, signed_params, signed_params_len);
1480 if (!CBS_skip(¶ms, 2 * SSL3_RANDOM_SIZE))
1481 goto err;
1482
1483 if (!CBB_add_bytes(&server_kex, CBS_data(¶ms),
1484 CBS_len(¶ms)))
1485 goto err;
1486
1487 /* Add signature unless anonymous. */
1488 if (!(s->s3->hs.cipher->algorithm_auth & SSL_aNULL)) {
1489 if ((pkey = ssl_get_sign_pkey(s, s->s3->hs.cipher,
1490 &md, &sigalg)) == NULL) {
1491 al = SSL_AD_DECODE_ERROR;
1492 goto fatal_err;
1493 }
1494 s->s3->hs.our_sigalg = sigalg;
1495
1496 /* Send signature algorithm. */
1497 if (SSL_USE_SIGALGS(s)) {
1498 if (!CBB_add_u16(&server_kex, sigalg->value)) {
1499 al = SSL_AD_INTERNAL_ERROR;
1500 SSLerror(s, ERR_R_INTERNAL_ERROR);
1501 goto fatal_err;
1502 }
1503 }
1504
1505 if (!EVP_DigestSignInit(md_ctx, &pctx, md, NULL, pkey)) {
1506 SSLerror(s, ERR_R_EVP_LIB);
1507 goto err;
1508 }
1509 if ((sigalg->flags & SIGALG_FLAG_RSA_PSS) &&
1510 (!EVP_PKEY_CTX_set_rsa_padding(pctx,
1511 RSA_PKCS1_PSS_PADDING) ||
1512 !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1))) {
1513 SSLerror(s, ERR_R_EVP_LIB);
1514 goto err;
1515 }
1516 if (!EVP_DigestSign(md_ctx, NULL, &signature_len,
1517 signed_params, signed_params_len)) {
1518 SSLerror(s, ERR_R_EVP_LIB);
1519 goto err;
1520 }
1521 if ((signature = calloc(1, signature_len)) == NULL) {
1522 SSLerror(s, ERR_R_MALLOC_FAILURE);
1523 goto err;
1524 }
1525 if (!EVP_DigestSign(md_ctx, signature, &signature_len,
1526 signed_params, signed_params_len)) {
1527 SSLerror(s, ERR_R_EVP_LIB);
1528 goto err;
1529 }
1530
1531 if (!CBB_add_u16_length_prefixed(&server_kex,
1532 &cbb_signature))
1533 goto err;
1534 if (!CBB_add_bytes(&cbb_signature, signature,
1535 signature_len))
1536 goto err;
1537 }
1538
1539 if (!ssl3_handshake_msg_finish(s, &cbb))
1540 goto err;
1541
1542 s->s3->hs.state = SSL3_ST_SW_KEY_EXCH_B;
1543 }
1544
1545 EVP_MD_CTX_free(md_ctx);
1546 free(signature);
1547 free(signed_params);
1548
1549 return (ssl3_handshake_write(s));
1550
1551 fatal_err:
1552 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1553 err:
1554 CBB_cleanup(&cbb_signed_params);
1555 CBB_cleanup(&cbb);
1556 EVP_MD_CTX_free(md_ctx);
1557 free(signature);
1558 free(signed_params);
1559
1560 return (-1);
1561 }
1562
1563 static int
ssl3_send_certificate_request(SSL * s)1564 ssl3_send_certificate_request(SSL *s)
1565 {
1566 CBB cbb, cert_request, cert_types, sigalgs, cert_auth, dn;
1567 STACK_OF(X509_NAME) *sk = NULL;
1568 X509_NAME *name;
1569 int i;
1570
1571 /*
1572 * Certificate Request - RFC 5246 section 7.4.4.
1573 */
1574
1575 memset(&cbb, 0, sizeof(cbb));
1576
1577 if (s->s3->hs.state == SSL3_ST_SW_CERT_REQ_A) {
1578 if (!ssl3_handshake_msg_start(s, &cbb, &cert_request,
1579 SSL3_MT_CERTIFICATE_REQUEST))
1580 goto err;
1581
1582 if (!CBB_add_u8_length_prefixed(&cert_request, &cert_types))
1583 goto err;
1584 if (!ssl3_get_req_cert_types(s, &cert_types))
1585 goto err;
1586
1587 if (SSL_USE_SIGALGS(s)) {
1588 if (!CBB_add_u16_length_prefixed(&cert_request,
1589 &sigalgs))
1590 goto err;
1591 if (!ssl_sigalgs_build(s->s3->hs.negotiated_tls_version,
1592 &sigalgs, SSL_get_security_level(s)))
1593 goto err;
1594 }
1595
1596 if (!CBB_add_u16_length_prefixed(&cert_request, &cert_auth))
1597 goto err;
1598
1599 sk = SSL_get_client_CA_list(s);
1600 for (i = 0; i < sk_X509_NAME_num(sk); i++) {
1601 unsigned char *name_data;
1602 size_t name_len;
1603
1604 name = sk_X509_NAME_value(sk, i);
1605 name_len = i2d_X509_NAME(name, NULL);
1606
1607 if (!CBB_add_u16_length_prefixed(&cert_auth, &dn))
1608 goto err;
1609 if (!CBB_add_space(&dn, &name_data, name_len))
1610 goto err;
1611 if (i2d_X509_NAME(name, &name_data) != name_len)
1612 goto err;
1613 }
1614
1615 if (!ssl3_handshake_msg_finish(s, &cbb))
1616 goto err;
1617
1618 s->s3->hs.state = SSL3_ST_SW_CERT_REQ_B;
1619 }
1620
1621 /* SSL3_ST_SW_CERT_REQ_B */
1622 return (ssl3_handshake_write(s));
1623
1624 err:
1625 CBB_cleanup(&cbb);
1626
1627 return (-1);
1628 }
1629
1630 static int
ssl3_get_client_kex_rsa(SSL * s,CBS * cbs)1631 ssl3_get_client_kex_rsa(SSL *s, CBS *cbs)
1632 {
1633 uint8_t fakepms[SSL_MAX_MASTER_KEY_LENGTH];
1634 uint8_t *pms = NULL;
1635 size_t pms_len = 0;
1636 size_t pad_len;
1637 EVP_PKEY *pkey = NULL;
1638 RSA *rsa = NULL;
1639 CBS enc_pms;
1640 int decrypt_len;
1641 uint8_t mask;
1642 size_t i;
1643 int valid = 1;
1644 int ret = 0;
1645
1646 /*
1647 * Handle key exchange in the form of an RSA-Encrypted Premaster Secret
1648 * Message. See RFC 5246, section 7.4.7.1.
1649 */
1650
1651 arc4random_buf(fakepms, sizeof(fakepms));
1652
1653 fakepms[0] = s->s3->hs.peer_legacy_version >> 8;
1654 fakepms[1] = s->s3->hs.peer_legacy_version & 0xff;
1655
1656 pkey = s->cert->pkeys[SSL_PKEY_RSA].privatekey;
1657 if (pkey == NULL || (rsa = EVP_PKEY_get0_RSA(pkey)) == NULL) {
1658 SSLerror(s, SSL_R_MISSING_RSA_CERTIFICATE);
1659 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
1660 goto err;
1661 }
1662
1663 /*
1664 * The minimum size of an encrypted premaster secret is 11 bytes of
1665 * padding (00 02 <8 or more non-zero bytes> 00) (RFC 8017, section
1666 * 9.2) and 48 bytes of premaster secret (RFC 5246, section 7.4.7.1).
1667 * This means an RSA key size of at least 472 bits.
1668 */
1669 pms_len = RSA_size(rsa);
1670 if (pms_len < 11 + SSL_MAX_MASTER_KEY_LENGTH) {
1671 SSLerror(s, SSL_R_DECRYPTION_FAILED);
1672 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
1673 goto err;
1674 }
1675 pad_len = pms_len - SSL_MAX_MASTER_KEY_LENGTH;
1676
1677 if (!CBS_get_u16_length_prefixed(cbs, &enc_pms)) {
1678 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
1679 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1680 goto err;
1681 }
1682 if (CBS_len(&enc_pms) != pms_len || CBS_len(cbs) != 0) {
1683 SSLerror(s, SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG);
1684 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1685 goto err;
1686 }
1687
1688 if ((pms = calloc(1, pms_len)) == NULL)
1689 goto err;
1690
1691 decrypt_len = RSA_private_decrypt(CBS_len(&enc_pms), CBS_data(&enc_pms),
1692 pms, rsa, RSA_NO_PADDING);
1693
1694 if (decrypt_len != pms_len) {
1695 SSLerror(s, SSL_R_DECRYPTION_FAILED);
1696 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
1697 goto err;
1698 }
1699
1700 /*
1701 * All processing from here on needs to avoid leaking any information
1702 * about the decrypted content, in order to prevent oracle attacks and
1703 * minimise timing attacks.
1704 */
1705
1706 /* Check padding - 00 02 <8 or more non-zero bytes> 00 */
1707 valid &= crypto_ct_eq_u8(pms[0], 0x00);
1708 valid &= crypto_ct_eq_u8(pms[1], 0x02);
1709 for (i = 2; i < pad_len - 1; i++)
1710 valid &= crypto_ct_ne_u8(pms[i], 0x00);
1711 valid &= crypto_ct_eq_u8(pms[pad_len - 1], 0x00);
1712
1713 /* Ensure client version in premaster secret matches ClientHello version. */
1714 valid &= crypto_ct_eq_u8(pms[pad_len + 0], s->s3->hs.peer_legacy_version >> 8);
1715 valid &= crypto_ct_eq_u8(pms[pad_len + 1], s->s3->hs.peer_legacy_version & 0xff);
1716
1717 /* Use the premaster secret if padding is correct, if not use the fake. */
1718 mask = crypto_ct_eq_mask_u8(valid, 1);
1719 for (i = 0; i < SSL_MAX_MASTER_KEY_LENGTH; i++)
1720 pms[i] = (pms[pad_len + i] & mask) | (fakepms[i] & ~mask);
1721
1722 if (!tls12_derive_master_secret(s, pms, SSL_MAX_MASTER_KEY_LENGTH))
1723 goto err;
1724
1725 ret = 1;
1726
1727 err:
1728 freezero(pms, pms_len);
1729
1730 return ret;
1731 }
1732
1733 static int
ssl3_get_client_kex_dhe(SSL * s,CBS * cbs)1734 ssl3_get_client_kex_dhe(SSL *s, CBS *cbs)
1735 {
1736 uint8_t *key = NULL;
1737 size_t key_len = 0;
1738 int decode_error, invalid_key;
1739 int ret = 0;
1740
1741 if (s->s3->hs.key_share == NULL) {
1742 SSLerror(s, SSL_R_MISSING_TMP_DH_KEY);
1743 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
1744 goto err;
1745 }
1746
1747 if (!tls_key_share_peer_public(s->s3->hs.key_share, cbs,
1748 &decode_error, &invalid_key)) {
1749 if (decode_error) {
1750 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
1751 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1752 }
1753 goto err;
1754 }
1755 if (invalid_key) {
1756 SSLerror(s, SSL_R_BAD_DH_PUB_KEY_LENGTH);
1757 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
1758 goto err;
1759 }
1760
1761 if (!tls_key_share_derive(s->s3->hs.key_share, &key, &key_len))
1762 goto err;
1763
1764 if (!tls12_derive_master_secret(s, key, key_len))
1765 goto err;
1766
1767 ret = 1;
1768
1769 err:
1770 freezero(key, key_len);
1771
1772 return ret;
1773 }
1774
1775 static int
ssl3_get_client_kex_ecdhe(SSL * s,CBS * cbs)1776 ssl3_get_client_kex_ecdhe(SSL *s, CBS *cbs)
1777 {
1778 uint8_t *key = NULL;
1779 size_t key_len = 0;
1780 int decode_error;
1781 CBS public;
1782 int ret = 0;
1783
1784 if (s->s3->hs.key_share == NULL) {
1785 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
1786 SSLerror(s, SSL_R_MISSING_TMP_DH_KEY);
1787 goto err;
1788 }
1789
1790 if (!CBS_get_u8_length_prefixed(cbs, &public)) {
1791 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
1792 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1793 goto err;
1794 }
1795 if (!tls_key_share_peer_public(s->s3->hs.key_share, &public,
1796 &decode_error, NULL)) {
1797 if (decode_error) {
1798 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
1799 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1800 }
1801 goto err;
1802 }
1803
1804 if (!tls_key_share_derive(s->s3->hs.key_share, &key, &key_len))
1805 goto err;
1806
1807 if (!tls12_derive_master_secret(s, key, key_len))
1808 goto err;
1809
1810 ret = 1;
1811
1812 err:
1813 freezero(key, key_len);
1814
1815 return ret;
1816 }
1817
1818 static int
ssl3_get_client_key_exchange(SSL * s)1819 ssl3_get_client_key_exchange(SSL *s)
1820 {
1821 unsigned long alg_k;
1822 int al, ret;
1823 CBS cbs;
1824
1825 /* 2048 maxlen is a guess. How long a key does that permit? */
1826 if ((ret = ssl3_get_message(s, SSL3_ST_SR_KEY_EXCH_A,
1827 SSL3_ST_SR_KEY_EXCH_B, SSL3_MT_CLIENT_KEY_EXCHANGE, 2048)) <= 0)
1828 return ret;
1829
1830 if (s->init_num < 0)
1831 goto err;
1832
1833 CBS_init(&cbs, s->init_msg, s->init_num);
1834
1835 alg_k = s->s3->hs.cipher->algorithm_mkey;
1836
1837 if (alg_k & SSL_kRSA) {
1838 if (!ssl3_get_client_kex_rsa(s, &cbs))
1839 goto err;
1840 } else if (alg_k & SSL_kDHE) {
1841 if (!ssl3_get_client_kex_dhe(s, &cbs))
1842 goto err;
1843 } else if (alg_k & SSL_kECDHE) {
1844 if (!ssl3_get_client_kex_ecdhe(s, &cbs))
1845 goto err;
1846 } else {
1847 al = SSL_AD_HANDSHAKE_FAILURE;
1848 SSLerror(s, SSL_R_UNKNOWN_CIPHER_TYPE);
1849 goto fatal_err;
1850 }
1851
1852 if (CBS_len(&cbs) != 0) {
1853 al = SSL_AD_DECODE_ERROR;
1854 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
1855 goto fatal_err;
1856 }
1857
1858 return (1);
1859
1860 fatal_err:
1861 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1862 err:
1863 return (-1);
1864 }
1865
1866 static int
ssl3_get_cert_verify(SSL * s)1867 ssl3_get_cert_verify(SSL *s)
1868 {
1869 CBS cbs, signature;
1870 const struct ssl_sigalg *sigalg = NULL;
1871 uint16_t sigalg_value = SIGALG_NONE;
1872 EVP_PKEY *pkey;
1873 X509 *peer_cert = NULL;
1874 EVP_MD_CTX *mctx = NULL;
1875 int al, verify;
1876 const unsigned char *hdata;
1877 size_t hdatalen;
1878 int type = 0;
1879 int ret;
1880
1881 if ((ret = ssl3_get_message(s, SSL3_ST_SR_CERT_VRFY_A,
1882 SSL3_ST_SR_CERT_VRFY_B, -1, SSL3_RT_MAX_PLAIN_LENGTH)) <= 0)
1883 return ret;
1884
1885 ret = 0;
1886
1887 if (s->init_num < 0)
1888 goto err;
1889
1890 if ((mctx = EVP_MD_CTX_new()) == NULL)
1891 goto err;
1892
1893 CBS_init(&cbs, s->init_msg, s->init_num);
1894
1895 peer_cert = s->session->peer_cert;
1896 pkey = X509_get0_pubkey(peer_cert);
1897 type = X509_certificate_type(peer_cert, pkey);
1898
1899 if (s->s3->hs.tls12.message_type != SSL3_MT_CERTIFICATE_VERIFY) {
1900 s->s3->hs.tls12.reuse_message = 1;
1901 if (peer_cert != NULL) {
1902 al = SSL_AD_UNEXPECTED_MESSAGE;
1903 SSLerror(s, SSL_R_MISSING_VERIFY_MESSAGE);
1904 goto fatal_err;
1905 }
1906 ret = 1;
1907 goto end;
1908 }
1909
1910 if (peer_cert == NULL) {
1911 SSLerror(s, SSL_R_NO_CLIENT_CERT_RECEIVED);
1912 al = SSL_AD_UNEXPECTED_MESSAGE;
1913 goto fatal_err;
1914 }
1915
1916 if (!(type & EVP_PKT_SIGN)) {
1917 SSLerror(s, SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE);
1918 al = SSL_AD_ILLEGAL_PARAMETER;
1919 goto fatal_err;
1920 }
1921
1922 if (s->s3->change_cipher_spec) {
1923 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
1924 al = SSL_AD_UNEXPECTED_MESSAGE;
1925 goto fatal_err;
1926 }
1927
1928 if (SSL_USE_SIGALGS(s)) {
1929 if (!CBS_get_u16(&cbs, &sigalg_value))
1930 goto decode_err;
1931 }
1932 if (!CBS_get_u16_length_prefixed(&cbs, &signature))
1933 goto err;
1934 if (CBS_len(&cbs) != 0) {
1935 al = SSL_AD_DECODE_ERROR;
1936 SSLerror(s, SSL_R_EXTRA_DATA_IN_MESSAGE);
1937 goto fatal_err;
1938 }
1939
1940 if (CBS_len(&signature) > EVP_PKEY_size(pkey)) {
1941 SSLerror(s, SSL_R_WRONG_SIGNATURE_SIZE);
1942 al = SSL_AD_DECODE_ERROR;
1943 goto fatal_err;
1944 }
1945
1946 if ((sigalg = ssl_sigalg_for_peer(s, pkey,
1947 sigalg_value)) == NULL) {
1948 al = SSL_AD_DECODE_ERROR;
1949 goto fatal_err;
1950 }
1951 s->s3->hs.peer_sigalg = sigalg;
1952
1953 if (SSL_USE_SIGALGS(s)) {
1954 EVP_PKEY_CTX *pctx;
1955
1956 if (!tls1_transcript_data(s, &hdata, &hdatalen)) {
1957 SSLerror(s, ERR_R_INTERNAL_ERROR);
1958 al = SSL_AD_INTERNAL_ERROR;
1959 goto fatal_err;
1960 }
1961 if (!EVP_DigestVerifyInit(mctx, &pctx, sigalg->md(),
1962 NULL, pkey)) {
1963 SSLerror(s, ERR_R_EVP_LIB);
1964 al = SSL_AD_INTERNAL_ERROR;
1965 goto fatal_err;
1966 }
1967 if ((sigalg->flags & SIGALG_FLAG_RSA_PSS) &&
1968 (!EVP_PKEY_CTX_set_rsa_padding(pctx,
1969 RSA_PKCS1_PSS_PADDING) ||
1970 !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1))) {
1971 al = SSL_AD_INTERNAL_ERROR;
1972 goto fatal_err;
1973 }
1974 if (EVP_DigestVerify(mctx, CBS_data(&signature),
1975 CBS_len(&signature), hdata, hdatalen) <= 0) {
1976 SSLerror(s, ERR_R_EVP_LIB);
1977 al = SSL_AD_INTERNAL_ERROR;
1978 goto fatal_err;
1979 }
1980 } else if (EVP_PKEY_id(pkey) == EVP_PKEY_RSA) {
1981 RSA *rsa;
1982
1983 if ((rsa = EVP_PKEY_get0_RSA(pkey)) == NULL) {
1984 al = SSL_AD_INTERNAL_ERROR;
1985 SSLerror(s, ERR_R_EVP_LIB);
1986 goto fatal_err;
1987 }
1988 verify = RSA_verify(NID_md5_sha1, s->s3->hs.tls12.cert_verify,
1989 MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH, CBS_data(&signature),
1990 CBS_len(&signature), rsa);
1991 if (verify < 0) {
1992 al = SSL_AD_DECRYPT_ERROR;
1993 SSLerror(s, SSL_R_BAD_RSA_DECRYPT);
1994 goto fatal_err;
1995 }
1996 if (verify == 0) {
1997 al = SSL_AD_DECRYPT_ERROR;
1998 SSLerror(s, SSL_R_BAD_RSA_SIGNATURE);
1999 goto fatal_err;
2000 }
2001 } else if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) {
2002 EC_KEY *eckey;
2003
2004 if ((eckey = EVP_PKEY_get0_EC_KEY(pkey)) == NULL) {
2005 al = SSL_AD_INTERNAL_ERROR;
2006 SSLerror(s, ERR_R_EVP_LIB);
2007 goto fatal_err;
2008 }
2009 verify = ECDSA_verify(0,
2010 &(s->s3->hs.tls12.cert_verify[MD5_DIGEST_LENGTH]),
2011 SHA_DIGEST_LENGTH, CBS_data(&signature),
2012 CBS_len(&signature), eckey);
2013 if (verify <= 0) {
2014 al = SSL_AD_DECRYPT_ERROR;
2015 SSLerror(s, SSL_R_BAD_ECDSA_SIGNATURE);
2016 goto fatal_err;
2017 }
2018 } else {
2019 SSLerror(s, ERR_R_INTERNAL_ERROR);
2020 al = SSL_AD_UNSUPPORTED_CERTIFICATE;
2021 goto fatal_err;
2022 }
2023
2024 ret = 1;
2025 if (0) {
2026 decode_err:
2027 al = SSL_AD_DECODE_ERROR;
2028 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
2029 fatal_err:
2030 ssl3_send_alert(s, SSL3_AL_FATAL, al);
2031 }
2032 end:
2033 tls1_transcript_free(s);
2034 err:
2035 EVP_MD_CTX_free(mctx);
2036
2037 return (ret);
2038 }
2039
2040 static int
ssl3_get_client_certificate(SSL * s)2041 ssl3_get_client_certificate(SSL *s)
2042 {
2043 CBS cbs, cert_list, cert_data;
2044 STACK_OF(X509) *certs = NULL;
2045 X509 *cert = NULL;
2046 const uint8_t *p;
2047 int al, ret;
2048
2049 if ((ret = ssl3_get_message(s, SSL3_ST_SR_CERT_A, SSL3_ST_SR_CERT_B,
2050 -1, s->max_cert_list)) <= 0)
2051 return ret;
2052
2053 ret = -1;
2054
2055 if (s->s3->hs.tls12.message_type == SSL3_MT_CLIENT_KEY_EXCHANGE) {
2056 if ((s->verify_mode & SSL_VERIFY_PEER) &&
2057 (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
2058 SSLerror(s, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
2059 al = SSL_AD_HANDSHAKE_FAILURE;
2060 goto fatal_err;
2061 }
2062
2063 /*
2064 * If we asked for a client certificate and the client has none,
2065 * it must respond with a certificate list of length zero.
2066 */
2067 if (s->s3->hs.tls12.cert_request != 0) {
2068 SSLerror(s, SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST);
2069 al = SSL_AD_UNEXPECTED_MESSAGE;
2070 goto fatal_err;
2071 }
2072 s->s3->hs.tls12.reuse_message = 1;
2073 return (1);
2074 }
2075
2076 if (s->s3->hs.tls12.message_type != SSL3_MT_CERTIFICATE) {
2077 al = SSL_AD_UNEXPECTED_MESSAGE;
2078 SSLerror(s, SSL_R_WRONG_MESSAGE_TYPE);
2079 goto fatal_err;
2080 }
2081
2082 if (s->init_num < 0)
2083 goto decode_err;
2084
2085 CBS_init(&cbs, s->init_msg, s->init_num);
2086
2087 if (!CBS_get_u24_length_prefixed(&cbs, &cert_list))
2088 goto decode_err;
2089 if (CBS_len(&cbs) != 0)
2090 goto decode_err;
2091
2092 /*
2093 * A TLS client must send an empty certificate list, if no suitable
2094 * certificate is available (rather than omitting the Certificate
2095 * handshake message) - see RFC 5246 section 7.4.6.
2096 */
2097 if (CBS_len(&cert_list) == 0) {
2098 if ((s->verify_mode & SSL_VERIFY_PEER) &&
2099 (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
2100 SSLerror(s, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
2101 al = SSL_AD_HANDSHAKE_FAILURE;
2102 goto fatal_err;
2103 }
2104 /* No client certificate so free transcript. */
2105 tls1_transcript_free(s);
2106 goto done;
2107 }
2108
2109 if ((certs = sk_X509_new_null()) == NULL) {
2110 SSLerror(s, ERR_R_MALLOC_FAILURE);
2111 goto err;
2112 }
2113
2114 while (CBS_len(&cert_list) > 0) {
2115 if (!CBS_get_u24_length_prefixed(&cert_list, &cert_data))
2116 goto decode_err;
2117 p = CBS_data(&cert_data);
2118 if ((cert = d2i_X509(NULL, &p, CBS_len(&cert_data))) == NULL) {
2119 SSLerror(s, ERR_R_ASN1_LIB);
2120 goto err;
2121 }
2122 if (p != CBS_data(&cert_data) + CBS_len(&cert_data))
2123 goto decode_err;
2124 if (!sk_X509_push(certs, cert)) {
2125 SSLerror(s, ERR_R_MALLOC_FAILURE);
2126 goto err;
2127 }
2128 cert = NULL;
2129 }
2130
2131 if (ssl_verify_cert_chain(s, certs) <= 0) {
2132 al = ssl_verify_alarm_type(s->verify_result);
2133 SSLerror(s, SSL_R_NO_CERTIFICATE_RETURNED);
2134 goto fatal_err;
2135 }
2136 s->session->verify_result = s->verify_result;
2137 ERR_clear_error();
2138
2139 if (!tls_process_peer_certs(s, certs))
2140 goto err;
2141
2142 done:
2143 ret = 1;
2144 if (0) {
2145 decode_err:
2146 al = SSL_AD_DECODE_ERROR;
2147 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
2148 fatal_err:
2149 ssl3_send_alert(s, SSL3_AL_FATAL, al);
2150 }
2151 err:
2152 sk_X509_pop_free(certs, X509_free);
2153 X509_free(cert);
2154
2155 return (ret);
2156 }
2157
2158 static int
ssl3_send_server_certificate(SSL * s)2159 ssl3_send_server_certificate(SSL *s)
2160 {
2161 CBB cbb, server_cert;
2162 SSL_CERT_PKEY *cpk;
2163
2164 /*
2165 * Server Certificate - RFC 5246, section 7.4.2.
2166 */
2167
2168 memset(&cbb, 0, sizeof(cbb));
2169
2170 if (s->s3->hs.state == SSL3_ST_SW_CERT_A) {
2171 if ((cpk = ssl_get_server_send_pkey(s)) == NULL) {
2172 SSLerror(s, ERR_R_INTERNAL_ERROR);
2173 return (0);
2174 }
2175
2176 if (!ssl3_handshake_msg_start(s, &cbb, &server_cert,
2177 SSL3_MT_CERTIFICATE))
2178 goto err;
2179 if (!ssl3_output_cert_chain(s, &server_cert, cpk))
2180 goto err;
2181 if (!ssl3_handshake_msg_finish(s, &cbb))
2182 goto err;
2183
2184 s->s3->hs.state = SSL3_ST_SW_CERT_B;
2185 }
2186
2187 /* SSL3_ST_SW_CERT_B */
2188 return (ssl3_handshake_write(s));
2189
2190 err:
2191 CBB_cleanup(&cbb);
2192
2193 return (0);
2194 }
2195
2196 /* send a new session ticket (not necessarily for a new session) */
2197 static int
ssl3_send_newsession_ticket(SSL * s)2198 ssl3_send_newsession_ticket(SSL *s)
2199 {
2200 CBB cbb, session_ticket, ticket;
2201 SSL_CTX *tctx = s->initial_ctx;
2202 size_t enc_session_len, enc_session_max_len, hmac_len;
2203 size_t session_len = 0;
2204 unsigned char *enc_session = NULL, *session = NULL;
2205 unsigned char iv[EVP_MAX_IV_LENGTH];
2206 unsigned char key_name[16];
2207 unsigned char *hmac;
2208 unsigned int hlen;
2209 EVP_CIPHER_CTX *ctx = NULL;
2210 HMAC_CTX *hctx = NULL;
2211 int iv_len, len;
2212
2213 /*
2214 * New Session Ticket - RFC 5077, section 3.3.
2215 */
2216
2217 memset(&cbb, 0, sizeof(cbb));
2218
2219 if ((ctx = EVP_CIPHER_CTX_new()) == NULL)
2220 goto err;
2221 if ((hctx = HMAC_CTX_new()) == NULL)
2222 goto err;
2223
2224 if (s->s3->hs.state == SSL3_ST_SW_SESSION_TICKET_A) {
2225 if (!ssl3_handshake_msg_start(s, &cbb, &session_ticket,
2226 SSL3_MT_NEWSESSION_TICKET))
2227 goto err;
2228
2229 if (!SSL_SESSION_ticket(s->session, &session, &session_len))
2230 goto err;
2231 if (session_len > 0xffff)
2232 goto err;
2233
2234 /*
2235 * Initialize HMAC and cipher contexts. If callback is present
2236 * it does all the work, otherwise use generated values from
2237 * parent context.
2238 */
2239 if (tctx->tlsext_ticket_key_cb != NULL) {
2240 if (tctx->tlsext_ticket_key_cb(s,
2241 key_name, iv, ctx, hctx, 1) < 0)
2242 goto err;
2243 } else {
2244 arc4random_buf(iv, 16);
2245 EVP_EncryptInit_ex(ctx, EVP_aes_128_cbc(), NULL,
2246 tctx->tlsext_tick_aes_key, iv);
2247 HMAC_Init_ex(hctx, tctx->tlsext_tick_hmac_key,
2248 16, EVP_sha256(), NULL);
2249 memcpy(key_name, tctx->tlsext_tick_key_name, 16);
2250 }
2251
2252 /* Encrypt the session state. */
2253 enc_session_max_len = session_len + EVP_MAX_BLOCK_LENGTH;
2254 if ((enc_session = calloc(1, enc_session_max_len)) == NULL)
2255 goto err;
2256 enc_session_len = 0;
2257 if (!EVP_EncryptUpdate(ctx, enc_session, &len, session,
2258 session_len))
2259 goto err;
2260 enc_session_len += len;
2261 if (!EVP_EncryptFinal_ex(ctx, enc_session + enc_session_len,
2262 &len))
2263 goto err;
2264 enc_session_len += len;
2265
2266 if (enc_session_len > enc_session_max_len)
2267 goto err;
2268
2269 /* Generate the HMAC. */
2270 if (!HMAC_Update(hctx, key_name, sizeof(key_name)))
2271 goto err;
2272 if (!HMAC_Update(hctx, iv, EVP_CIPHER_CTX_iv_length(ctx)))
2273 goto err;
2274 if (!HMAC_Update(hctx, enc_session, enc_session_len))
2275 goto err;
2276
2277 if ((hmac_len = HMAC_size(hctx)) <= 0)
2278 goto err;
2279
2280 /*
2281 * Ticket lifetime hint (advisory only):
2282 * We leave this unspecified for resumed session
2283 * (for simplicity), and guess that tickets for new
2284 * sessions will live as long as their sessions.
2285 */
2286 if (!CBB_add_u32(&session_ticket,
2287 s->hit ? 0 : s->session->timeout))
2288 goto err;
2289
2290 if (!CBB_add_u16_length_prefixed(&session_ticket, &ticket))
2291 goto err;
2292 if (!CBB_add_bytes(&ticket, key_name, sizeof(key_name)))
2293 goto err;
2294 if ((iv_len = EVP_CIPHER_CTX_iv_length(ctx)) < 0)
2295 goto err;
2296 if (!CBB_add_bytes(&ticket, iv, iv_len))
2297 goto err;
2298 if (!CBB_add_bytes(&ticket, enc_session, enc_session_len))
2299 goto err;
2300 if (!CBB_add_space(&ticket, &hmac, hmac_len))
2301 goto err;
2302
2303 if (!HMAC_Final(hctx, hmac, &hlen))
2304 goto err;
2305 if (hlen != hmac_len)
2306 goto err;
2307
2308 if (!ssl3_handshake_msg_finish(s, &cbb))
2309 goto err;
2310
2311 s->s3->hs.state = SSL3_ST_SW_SESSION_TICKET_B;
2312 }
2313
2314 EVP_CIPHER_CTX_free(ctx);
2315 HMAC_CTX_free(hctx);
2316 freezero(session, session_len);
2317 free(enc_session);
2318
2319 /* SSL3_ST_SW_SESSION_TICKET_B */
2320 return (ssl3_handshake_write(s));
2321
2322 err:
2323 CBB_cleanup(&cbb);
2324 EVP_CIPHER_CTX_free(ctx);
2325 HMAC_CTX_free(hctx);
2326 freezero(session, session_len);
2327 free(enc_session);
2328
2329 return (-1);
2330 }
2331
2332 static int
ssl3_send_cert_status(SSL * s)2333 ssl3_send_cert_status(SSL *s)
2334 {
2335 CBB cbb, certstatus, ocspresp;
2336
2337 memset(&cbb, 0, sizeof(cbb));
2338
2339 if (s->s3->hs.state == SSL3_ST_SW_CERT_STATUS_A) {
2340 if (!ssl3_handshake_msg_start(s, &cbb, &certstatus,
2341 SSL3_MT_CERTIFICATE_STATUS))
2342 goto err;
2343 if (!CBB_add_u8(&certstatus, s->tlsext_status_type))
2344 goto err;
2345 if (!CBB_add_u24_length_prefixed(&certstatus, &ocspresp))
2346 goto err;
2347 if (!CBB_add_bytes(&ocspresp, s->tlsext_ocsp_resp,
2348 s->tlsext_ocsp_resp_len))
2349 goto err;
2350 if (!ssl3_handshake_msg_finish(s, &cbb))
2351 goto err;
2352
2353 s->s3->hs.state = SSL3_ST_SW_CERT_STATUS_B;
2354 }
2355
2356 /* SSL3_ST_SW_CERT_STATUS_B */
2357 return (ssl3_handshake_write(s));
2358
2359 err:
2360 CBB_cleanup(&cbb);
2361
2362 return (-1);
2363 }
2364
2365 static int
ssl3_send_server_change_cipher_spec(SSL * s)2366 ssl3_send_server_change_cipher_spec(SSL *s)
2367 {
2368 size_t outlen;
2369 CBB cbb;
2370
2371 memset(&cbb, 0, sizeof(cbb));
2372
2373 if (s->s3->hs.state == SSL3_ST_SW_CHANGE_A) {
2374 if (!CBB_init_fixed(&cbb, s->init_buf->data,
2375 s->init_buf->length))
2376 goto err;
2377 if (!CBB_add_u8(&cbb, SSL3_MT_CCS))
2378 goto err;
2379 if (!CBB_finish(&cbb, NULL, &outlen))
2380 goto err;
2381
2382 if (outlen > INT_MAX)
2383 goto err;
2384
2385 s->init_num = (int)outlen;
2386 s->init_off = 0;
2387
2388 if (SSL_is_dtls(s)) {
2389 s->d1->handshake_write_seq =
2390 s->d1->next_handshake_write_seq;
2391 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
2392 s->d1->handshake_write_seq, 0, 0);
2393 dtls1_buffer_message(s, 1);
2394 }
2395
2396 s->s3->hs.state = SSL3_ST_SW_CHANGE_B;
2397 }
2398
2399 /* SSL3_ST_SW_CHANGE_B */
2400 return ssl3_record_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
2401
2402 err:
2403 CBB_cleanup(&cbb);
2404
2405 return -1;
2406 }
2407
2408 static int
ssl3_get_client_finished(SSL * s)2409 ssl3_get_client_finished(SSL *s)
2410 {
2411 int al, md_len, ret;
2412 CBS cbs;
2413
2414 /* should actually be 36+4 :-) */
2415 if ((ret = ssl3_get_message(s, SSL3_ST_SR_FINISHED_A,
2416 SSL3_ST_SR_FINISHED_B, SSL3_MT_FINISHED, 64)) <= 0)
2417 return ret;
2418
2419 /* If this occurs, we have missed a message */
2420 if (!s->s3->change_cipher_spec) {
2421 al = SSL_AD_UNEXPECTED_MESSAGE;
2422 SSLerror(s, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
2423 goto fatal_err;
2424 }
2425 s->s3->change_cipher_spec = 0;
2426
2427 md_len = TLS1_FINISH_MAC_LENGTH;
2428
2429 if (s->init_num < 0) {
2430 al = SSL_AD_DECODE_ERROR;
2431 SSLerror(s, SSL_R_BAD_DIGEST_LENGTH);
2432 goto fatal_err;
2433 }
2434
2435 CBS_init(&cbs, s->init_msg, s->init_num);
2436
2437 if (s->s3->hs.peer_finished_len != md_len ||
2438 CBS_len(&cbs) != md_len) {
2439 al = SSL_AD_DECODE_ERROR;
2440 SSLerror(s, SSL_R_BAD_DIGEST_LENGTH);
2441 goto fatal_err;
2442 }
2443
2444 if (!CBS_mem_equal(&cbs, s->s3->hs.peer_finished, CBS_len(&cbs))) {
2445 al = SSL_AD_DECRYPT_ERROR;
2446 SSLerror(s, SSL_R_DIGEST_CHECK_FAILED);
2447 goto fatal_err;
2448 }
2449
2450 /* Copy finished so we can use it for renegotiation checks. */
2451 OPENSSL_assert(md_len <= EVP_MAX_MD_SIZE);
2452 memcpy(s->s3->previous_client_finished,
2453 s->s3->hs.peer_finished, md_len);
2454 s->s3->previous_client_finished_len = md_len;
2455
2456 return (1);
2457 fatal_err:
2458 ssl3_send_alert(s, SSL3_AL_FATAL, al);
2459 return (0);
2460 }
2461
2462 static int
ssl3_send_server_finished(SSL * s)2463 ssl3_send_server_finished(SSL *s)
2464 {
2465 CBB cbb, finished;
2466
2467 memset(&cbb, 0, sizeof(cbb));
2468
2469 if (s->s3->hs.state == SSL3_ST_SW_FINISHED_A) {
2470 if (!tls12_derive_finished(s))
2471 goto err;
2472
2473 /* Copy finished so we can use it for renegotiation checks. */
2474 memcpy(s->s3->previous_server_finished,
2475 s->s3->hs.finished, s->s3->hs.finished_len);
2476 s->s3->previous_server_finished_len = s->s3->hs.finished_len;
2477
2478 if (!ssl3_handshake_msg_start(s, &cbb, &finished,
2479 SSL3_MT_FINISHED))
2480 goto err;
2481 if (!CBB_add_bytes(&finished, s->s3->hs.finished,
2482 s->s3->hs.finished_len))
2483 goto err;
2484 if (!ssl3_handshake_msg_finish(s, &cbb))
2485 goto err;
2486
2487 s->s3->hs.state = SSL3_ST_SW_FINISHED_B;
2488 }
2489
2490 return (ssl3_handshake_write(s));
2491
2492 err:
2493 CBB_cleanup(&cbb);
2494
2495 return (-1);
2496 }
2497