xref: /openbsd-src/lib/libssl/ssl_srvr.c (revision ffcef06798eb7b98532e76a80212f0772bebc4f6)
1 /* $OpenBSD: ssl_srvr.c,v 1.118 2021/08/30 19:25:43 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 <stdio.h>
152 
153 #include <openssl/bn.h>
154 #include <openssl/buffer.h>
155 #include <openssl/curve25519.h>
156 #include <openssl/evp.h>
157 #include <openssl/dh.h>
158 #include <openssl/hmac.h>
159 #include <openssl/md5.h>
160 #include <openssl/objects.h>
161 #include <openssl/opensslconf.h>
162 #include <openssl/x509.h>
163 
164 #ifndef OPENSSL_NO_GOST
165 #include <openssl/gost.h>
166 #endif
167 
168 #include "bytestring.h"
169 #include "dtls_locl.h"
170 #include "ssl_locl.h"
171 #include "ssl_sigalgs.h"
172 #include "ssl_tlsext.h"
173 
174 int
175 ssl3_accept(SSL *s)
176 {
177 	unsigned long alg_k;
178 	int new_state, state, skip = 0;
179 	int listen = 0;
180 	int ret = -1;
181 
182 	ERR_clear_error();
183 	errno = 0;
184 
185 	if (SSL_is_dtls(s))
186 		listen = D1I(s)->listen;
187 
188 	/* init things to blank */
189 	s->internal->in_handshake++;
190 	if (!SSL_in_init(s) || SSL_in_before(s))
191 		SSL_clear(s);
192 
193 	if (SSL_is_dtls(s))
194 		D1I(s)->listen = listen;
195 
196 	for (;;) {
197 		state = S3I(s)->hs.state;
198 
199 		switch (S3I(s)->hs.state) {
200 		case SSL_ST_RENEGOTIATE:
201 			s->internal->renegotiate = 1;
202 			/* S3I(s)->hs.state=SSL_ST_ACCEPT; */
203 
204 		case SSL_ST_BEFORE:
205 		case SSL_ST_ACCEPT:
206 		case SSL_ST_BEFORE|SSL_ST_ACCEPT:
207 		case SSL_ST_OK|SSL_ST_ACCEPT:
208 			s->server = 1;
209 
210 			ssl_info_callback(s, SSL_CB_HANDSHAKE_START, 1);
211 
212 			if (!ssl_legacy_stack_version(s, s->version)) {
213 				SSLerror(s, ERR_R_INTERNAL_ERROR);
214 				ret = -1;
215 				goto end;
216 			}
217 
218 			if (!ssl_supported_tls_version_range(s,
219 			    &S3I(s)->hs.our_min_tls_version,
220 			    &S3I(s)->hs.our_max_tls_version)) {
221 				SSLerror(s, SSL_R_NO_PROTOCOLS_AVAILABLE);
222 				ret = -1;
223 				goto end;
224 			}
225 
226 			if (!ssl3_setup_init_buffer(s)) {
227 				ret = -1;
228 				goto end;
229 			}
230 			if (!ssl3_setup_buffers(s)) {
231 				ret = -1;
232 				goto end;
233 			}
234 
235 			s->internal->init_num = 0;
236 
237 			if (S3I(s)->hs.state != SSL_ST_RENEGOTIATE) {
238 				/*
239 				 * Ok, we now need to push on a buffering BIO
240 				 * so that the output is sent in a way that
241 				 * TCP likes :-)
242 				 */
243 				if (!ssl_init_wbio_buffer(s, 1)) {
244 					ret = -1;
245 					goto end;
246 				}
247 
248 				if (!tls1_transcript_init(s)) {
249 					ret = -1;
250 					goto end;
251 				}
252 
253 				S3I(s)->hs.state = SSL3_ST_SR_CLNT_HELLO_A;
254 				s->ctx->internal->stats.sess_accept++;
255 			} else if (!SSL_is_dtls(s) && !S3I(s)->send_connection_binding) {
256 				/*
257 				 * Server attempting to renegotiate with
258 				 * client that doesn't support secure
259 				 * renegotiation.
260 				 */
261 				SSLerror(s, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
262 				ssl3_send_alert(s, SSL3_AL_FATAL,
263 				    SSL_AD_HANDSHAKE_FAILURE);
264 				ret = -1;
265 				goto end;
266 			} else {
267 				/*
268 				 * S3I(s)->hs.state == SSL_ST_RENEGOTIATE,
269 				 * we will just send a HelloRequest.
270 				 */
271 				s->ctx->internal->stats.sess_accept_renegotiate++;
272 				S3I(s)->hs.state = SSL3_ST_SW_HELLO_REQ_A;
273 			}
274 			break;
275 
276 		case SSL3_ST_SW_HELLO_REQ_A:
277 		case SSL3_ST_SW_HELLO_REQ_B:
278 			s->internal->shutdown = 0;
279 			if (SSL_is_dtls(s)) {
280 				dtls1_clear_record_buffer(s);
281 				dtls1_start_timer(s);
282 			}
283 			ret = ssl3_send_hello_request(s);
284 			if (ret <= 0)
285 				goto end;
286 			if (SSL_is_dtls(s))
287 				S3I(s)->hs.tls12.next_state = SSL3_ST_SR_CLNT_HELLO_A;
288 			else
289 				S3I(s)->hs.tls12.next_state = SSL3_ST_SW_HELLO_REQ_C;
290 			S3I(s)->hs.state = SSL3_ST_SW_FLUSH;
291 			s->internal->init_num = 0;
292 
293 			if (SSL_is_dtls(s)) {
294 				if (!tls1_transcript_init(s)) {
295 					ret = -1;
296 					goto end;
297 				}
298 			}
299 			break;
300 
301 		case SSL3_ST_SW_HELLO_REQ_C:
302 			S3I(s)->hs.state = SSL_ST_OK;
303 			break;
304 
305 		case SSL3_ST_SR_CLNT_HELLO_A:
306 		case SSL3_ST_SR_CLNT_HELLO_B:
307 		case SSL3_ST_SR_CLNT_HELLO_C:
308 			s->internal->shutdown = 0;
309 			if (SSL_is_dtls(s)) {
310 				ret = ssl3_get_client_hello(s);
311 				if (ret <= 0)
312 					goto end;
313 				dtls1_stop_timer(s);
314 
315 				if (ret == 1 &&
316 				    (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
317 					S3I(s)->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
318 				else
319 					S3I(s)->hs.state = SSL3_ST_SW_SRVR_HELLO_A;
320 
321 				s->internal->init_num = 0;
322 
323 				/*
324 				 * Reflect ClientHello sequence to remain
325 				 * stateless while listening.
326 				 */
327 				if (listen) {
328 					tls12_record_layer_reflect_seq_num(
329 					    s->internal->rl);
330 				}
331 
332 				/* If we're just listening, stop here */
333 				if (listen && S3I(s)->hs.state == SSL3_ST_SW_SRVR_HELLO_A) {
334 					ret = 2;
335 					D1I(s)->listen = 0;
336 					/*
337 					 * Set expected sequence numbers to
338 					 * continue the handshake.
339 					 */
340 					D1I(s)->handshake_read_seq = 2;
341 					D1I(s)->handshake_write_seq = 1;
342 					D1I(s)->next_handshake_write_seq = 1;
343 					goto end;
344 				}
345 			} else {
346 				if (s->internal->rwstate != SSL_X509_LOOKUP) {
347 					ret = ssl3_get_client_hello(s);
348 					if (ret <= 0)
349 						goto end;
350 				}
351 
352 				s->internal->renegotiate = 2;
353 				S3I(s)->hs.state = SSL3_ST_SW_SRVR_HELLO_A;
354 				s->internal->init_num = 0;
355 			}
356 			break;
357 
358 		case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
359 		case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
360 			ret = ssl3_send_dtls_hello_verify_request(s);
361 			if (ret <= 0)
362 				goto end;
363 			S3I(s)->hs.state = SSL3_ST_SW_FLUSH;
364 			S3I(s)->hs.tls12.next_state = SSL3_ST_SR_CLNT_HELLO_A;
365 
366 			/* HelloVerifyRequest resets Finished MAC. */
367 			tls1_transcript_reset(s);
368 			break;
369 
370 		case SSL3_ST_SW_SRVR_HELLO_A:
371 		case SSL3_ST_SW_SRVR_HELLO_B:
372 			if (SSL_is_dtls(s)) {
373 				s->internal->renegotiate = 2;
374 				dtls1_start_timer(s);
375 			}
376 			ret = ssl3_send_server_hello(s);
377 			if (ret <= 0)
378 				goto end;
379 			if (s->internal->hit) {
380 				if (s->internal->tlsext_ticket_expected)
381 					S3I(s)->hs.state = SSL3_ST_SW_SESSION_TICKET_A;
382 				else
383 					S3I(s)->hs.state = SSL3_ST_SW_CHANGE_A;
384 			} else {
385 				S3I(s)->hs.state = SSL3_ST_SW_CERT_A;
386 			}
387 			s->internal->init_num = 0;
388 			break;
389 
390 		case SSL3_ST_SW_CERT_A:
391 		case SSL3_ST_SW_CERT_B:
392 			/* Check if it is anon DH or anon ECDH. */
393 			if (!(S3I(s)->hs.cipher->algorithm_auth &
394 			    SSL_aNULL)) {
395 				if (SSL_is_dtls(s))
396 					dtls1_start_timer(s);
397 				ret = ssl3_send_server_certificate(s);
398 				if (ret <= 0)
399 					goto end;
400 				if (s->internal->tlsext_status_expected)
401 					S3I(s)->hs.state = SSL3_ST_SW_CERT_STATUS_A;
402 				else
403 					S3I(s)->hs.state = SSL3_ST_SW_KEY_EXCH_A;
404 			} else {
405 				skip = 1;
406 				S3I(s)->hs.state = SSL3_ST_SW_KEY_EXCH_A;
407 			}
408 			s->internal->init_num = 0;
409 			break;
410 
411 		case SSL3_ST_SW_KEY_EXCH_A:
412 		case SSL3_ST_SW_KEY_EXCH_B:
413 			alg_k = S3I(s)->hs.cipher->algorithm_mkey;
414 
415 			/*
416 			 * Only send if using a DH key exchange.
417 			 *
418 			 * For ECC ciphersuites, we send a ServerKeyExchange
419 			 * message only if the cipher suite is ECDHE. In other
420 			 * cases, the server certificate contains the server's
421 			 * public key for key exchange.
422 			 */
423 			if (alg_k & (SSL_kDHE|SSL_kECDHE)) {
424 				if (SSL_is_dtls(s))
425 					dtls1_start_timer(s);
426 				ret = ssl3_send_server_key_exchange(s);
427 				if (ret <= 0)
428 					goto end;
429 			} else
430 				skip = 1;
431 
432 			S3I(s)->hs.state = SSL3_ST_SW_CERT_REQ_A;
433 			s->internal->init_num = 0;
434 			break;
435 
436 		case SSL3_ST_SW_CERT_REQ_A:
437 		case SSL3_ST_SW_CERT_REQ_B:
438 			/*
439 			 * Determine whether or not we need to request a
440 			 * certificate.
441 			 *
442 			 * Do not request a certificate if:
443 			 *
444 			 * - We did not ask for it (SSL_VERIFY_PEER is unset).
445 			 *
446 			 * - SSL_VERIFY_CLIENT_ONCE is set and we are
447 			 *   renegotiating.
448 			 *
449 			 * - We are using an anonymous ciphersuites
450 			 *   (see section "Certificate request" in SSL 3 drafts
451 			 *   and in RFC 2246) ... except when the application
452 			 *   insists on verification (against the specs, but
453 			 *   s3_clnt.c accepts this for SSL 3).
454 			 */
455 			if (!(s->verify_mode & SSL_VERIFY_PEER) ||
456 			    ((s->session->peer != NULL) &&
457 			     (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
458 			    ((S3I(s)->hs.cipher->algorithm_auth &
459 			     SSL_aNULL) && !(s->verify_mode &
460 			     SSL_VERIFY_FAIL_IF_NO_PEER_CERT))) {
461 				/* No cert request. */
462 				skip = 1;
463 				S3I(s)->hs.tls12.cert_request = 0;
464 				S3I(s)->hs.state = SSL3_ST_SW_SRVR_DONE_A;
465 
466 				if (!SSL_is_dtls(s))
467 					tls1_transcript_free(s);
468 			} else {
469 				S3I(s)->hs.tls12.cert_request = 1;
470 				if (SSL_is_dtls(s))
471 					dtls1_start_timer(s);
472 				ret = ssl3_send_certificate_request(s);
473 				if (ret <= 0)
474 					goto end;
475 				S3I(s)->hs.state = SSL3_ST_SW_SRVR_DONE_A;
476 				s->internal->init_num = 0;
477 			}
478 			break;
479 
480 		case SSL3_ST_SW_SRVR_DONE_A:
481 		case SSL3_ST_SW_SRVR_DONE_B:
482 			if (SSL_is_dtls(s))
483 				dtls1_start_timer(s);
484 			ret = ssl3_send_server_done(s);
485 			if (ret <= 0)
486 				goto end;
487 			S3I(s)->hs.tls12.next_state = SSL3_ST_SR_CERT_A;
488 			S3I(s)->hs.state = SSL3_ST_SW_FLUSH;
489 			s->internal->init_num = 0;
490 			break;
491 
492 		case SSL3_ST_SW_FLUSH:
493 			/*
494 			 * This code originally checked to see if
495 			 * any data was pending using BIO_CTRL_INFO
496 			 * and then flushed. This caused problems
497 			 * as documented in PR#1939. The proposed
498 			 * fix doesn't completely resolve this issue
499 			 * as buggy implementations of BIO_CTRL_PENDING
500 			 * still exist. So instead we just flush
501 			 * unconditionally.
502 			 */
503 			s->internal->rwstate = SSL_WRITING;
504 			if (BIO_flush(s->wbio) <= 0) {
505 				if (SSL_is_dtls(s)) {
506 					/* If the write error was fatal, stop trying. */
507 					if (!BIO_should_retry(s->wbio)) {
508 						s->internal->rwstate = SSL_NOTHING;
509 						S3I(s)->hs.state = S3I(s)->hs.tls12.next_state;
510 					}
511 				}
512 				ret = -1;
513 				goto end;
514 			}
515 			s->internal->rwstate = SSL_NOTHING;
516 			S3I(s)->hs.state = S3I(s)->hs.tls12.next_state;
517 			break;
518 
519 		case SSL3_ST_SR_CERT_A:
520 		case SSL3_ST_SR_CERT_B:
521 			if (S3I(s)->hs.tls12.cert_request) {
522 				ret = ssl3_get_client_certificate(s);
523 				if (ret <= 0)
524 					goto end;
525 			}
526 			s->internal->init_num = 0;
527 			S3I(s)->hs.state = SSL3_ST_SR_KEY_EXCH_A;
528 			break;
529 
530 		case SSL3_ST_SR_KEY_EXCH_A:
531 		case SSL3_ST_SR_KEY_EXCH_B:
532 			ret = ssl3_get_client_key_exchange(s);
533 			if (ret <= 0)
534 				goto end;
535 
536 			if (SSL_is_dtls(s)) {
537 				S3I(s)->hs.state = SSL3_ST_SR_CERT_VRFY_A;
538 				s->internal->init_num = 0;
539 			}
540 
541 			alg_k = S3I(s)->hs.cipher->algorithm_mkey;
542 			if (ret == 2) {
543 				/*
544 				 * For the ECDH ciphersuites when
545 				 * the client sends its ECDH pub key in
546 				 * a certificate, the CertificateVerify
547 				 * message is not sent.
548 				 * Also for GOST ciphersuites when
549 				 * the client uses its key from the certificate
550 				 * for key exchange.
551 				 */
552 				S3I(s)->hs.state = SSL3_ST_SR_FINISHED_A;
553 				s->internal->init_num = 0;
554 			} else if (SSL_USE_SIGALGS(s) || (alg_k & SSL_kGOST)) {
555 				S3I(s)->hs.state = SSL3_ST_SR_CERT_VRFY_A;
556 				s->internal->init_num = 0;
557 				if (!s->session->peer)
558 					break;
559 				/*
560 				 * Freeze the transcript for use during client
561 				 * certificate verification.
562 				 */
563 				tls1_transcript_freeze(s);
564 			} else {
565 				S3I(s)->hs.state = SSL3_ST_SR_CERT_VRFY_A;
566 				s->internal->init_num = 0;
567 
568 				tls1_transcript_free(s);
569 
570 				/*
571 				 * We need to get hashes here so if there is
572 				 * a client cert, it can be verified.
573 				 */
574 				if (!tls1_transcript_hash_value(s,
575 				    S3I(s)->hs.tls12.cert_verify,
576 				    sizeof(S3I(s)->hs.tls12.cert_verify),
577 				    NULL)) {
578 					ret = -1;
579 					goto end;
580 				}
581 			}
582 			break;
583 
584 		case SSL3_ST_SR_CERT_VRFY_A:
585 		case SSL3_ST_SR_CERT_VRFY_B:
586 			if (SSL_is_dtls(s))
587 				D1I(s)->change_cipher_spec_ok = 1;
588 			else
589 				s->s3->flags |= SSL3_FLAGS_CCS_OK;
590 
591 			/* we should decide if we expected this one */
592 			ret = ssl3_get_cert_verify(s);
593 			if (ret <= 0)
594 				goto end;
595 			S3I(s)->hs.state = SSL3_ST_SR_FINISHED_A;
596 			s->internal->init_num = 0;
597 			break;
598 
599 		case SSL3_ST_SR_FINISHED_A:
600 		case SSL3_ST_SR_FINISHED_B:
601 			if (SSL_is_dtls(s))
602 				D1I(s)->change_cipher_spec_ok = 1;
603 			else
604 				s->s3->flags |= SSL3_FLAGS_CCS_OK;
605 			ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
606 			    SSL3_ST_SR_FINISHED_B);
607 			if (ret <= 0)
608 				goto end;
609 			if (SSL_is_dtls(s))
610 				dtls1_stop_timer(s);
611 			if (s->internal->hit)
612 				S3I(s)->hs.state = SSL_ST_OK;
613 			else if (s->internal->tlsext_ticket_expected)
614 				S3I(s)->hs.state = SSL3_ST_SW_SESSION_TICKET_A;
615 			else
616 				S3I(s)->hs.state = SSL3_ST_SW_CHANGE_A;
617 			s->internal->init_num = 0;
618 			break;
619 
620 		case SSL3_ST_SW_SESSION_TICKET_A:
621 		case SSL3_ST_SW_SESSION_TICKET_B:
622 			ret = ssl3_send_newsession_ticket(s);
623 			if (ret <= 0)
624 				goto end;
625 			S3I(s)->hs.state = SSL3_ST_SW_CHANGE_A;
626 			s->internal->init_num = 0;
627 			break;
628 
629 		case SSL3_ST_SW_CERT_STATUS_A:
630 		case SSL3_ST_SW_CERT_STATUS_B:
631 			ret = ssl3_send_cert_status(s);
632 			if (ret <= 0)
633 				goto end;
634 			S3I(s)->hs.state = SSL3_ST_SW_KEY_EXCH_A;
635 			s->internal->init_num = 0;
636 			break;
637 
638 		case SSL3_ST_SW_CHANGE_A:
639 		case SSL3_ST_SW_CHANGE_B:
640 			ret = ssl3_send_change_cipher_spec(s,
641 			    SSL3_ST_SW_CHANGE_A, SSL3_ST_SW_CHANGE_B);
642 			if (ret <= 0)
643 				goto end;
644 			S3I(s)->hs.state = SSL3_ST_SW_FINISHED_A;
645 			s->internal->init_num = 0;
646 			s->session->cipher = S3I(s)->hs.cipher;
647 
648 			if (!tls1_setup_key_block(s)) {
649 				ret = -1;
650 				goto end;
651 			}
652 			if (!tls1_change_write_cipher_state(s)) {
653 				ret = -1;
654 				goto end;
655 			}
656 			break;
657 
658 		case SSL3_ST_SW_FINISHED_A:
659 		case SSL3_ST_SW_FINISHED_B:
660 			ret = ssl3_send_finished(s, SSL3_ST_SW_FINISHED_A,
661 			    SSL3_ST_SW_FINISHED_B);
662 			if (ret <= 0)
663 				goto end;
664 			S3I(s)->hs.state = SSL3_ST_SW_FLUSH;
665 			if (s->internal->hit) {
666 				S3I(s)->hs.tls12.next_state = SSL3_ST_SR_FINISHED_A;
667 				tls1_transcript_free(s);
668 			} else
669 				S3I(s)->hs.tls12.next_state = SSL_ST_OK;
670 			s->internal->init_num = 0;
671 			break;
672 
673 		case SSL_ST_OK:
674 			/* clean a few things up */
675 			tls1_cleanup_key_block(s);
676 
677 			if (S3I(s)->handshake_transcript != NULL) {
678 				SSLerror(s, ERR_R_INTERNAL_ERROR);
679 				ret = -1;
680 				goto end;
681 			}
682 
683 			if (!SSL_is_dtls(s))
684 				ssl3_release_init_buffer(s);
685 
686 			/* remove buffering on output */
687 			ssl_free_wbio_buffer(s);
688 
689 			s->internal->init_num = 0;
690 
691 			/* Skipped if we just sent a HelloRequest. */
692 			if (s->internal->renegotiate == 2) {
693 				s->internal->renegotiate = 0;
694 				s->internal->new_session = 0;
695 
696 				ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
697 
698 				s->ctx->internal->stats.sess_accept_good++;
699 				/* s->server=1; */
700 				s->internal->handshake_func = ssl3_accept;
701 
702 				ssl_info_callback(s, SSL_CB_HANDSHAKE_DONE, 1);
703 			}
704 
705 			ret = 1;
706 
707 			if (SSL_is_dtls(s)) {
708 				/* Done handshaking, next message is client hello. */
709 				D1I(s)->handshake_read_seq = 0;
710 				/* Next message is server hello. */
711 				D1I(s)->handshake_write_seq = 0;
712 				D1I(s)->next_handshake_write_seq = 0;
713 			}
714 			goto end;
715 			/* break; */
716 
717 		default:
718 			SSLerror(s, SSL_R_UNKNOWN_STATE);
719 			ret = -1;
720 			goto end;
721 			/* break; */
722 		}
723 
724 		if (!S3I(s)->hs.tls12.reuse_message && !skip) {
725 			if (s->internal->debug) {
726 				if ((ret = BIO_flush(s->wbio)) <= 0)
727 					goto end;
728 			}
729 
730 
731 			if (S3I(s)->hs.state != state) {
732 				new_state = S3I(s)->hs.state;
733 				S3I(s)->hs.state = state;
734 				ssl_info_callback(s, SSL_CB_ACCEPT_LOOP, 1);
735 				S3I(s)->hs.state = new_state;
736 			}
737 		}
738 		skip = 0;
739 	}
740  end:
741 	/* BIO_flush(s->wbio); */
742 	s->internal->in_handshake--;
743 	ssl_info_callback(s, SSL_CB_ACCEPT_EXIT, ret);
744 
745 	return (ret);
746 }
747 
748 int
749 ssl3_send_hello_request(SSL *s)
750 {
751 	CBB cbb, hello;
752 
753 	memset(&cbb, 0, sizeof(cbb));
754 
755 	if (S3I(s)->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 		S3I(s)->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 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, ok, al, ret = -1, cookie_valid = 0;
783 	long n;
784 	unsigned long id;
785 	SSL_CIPHER *c;
786 	STACK_OF(SSL_CIPHER) *ciphers = NULL;
787 	unsigned long alg_k;
788 	const SSL_METHOD *method;
789 	uint16_t shared_version;
790 
791 	/*
792 	 * We do this so that we will respond with our native type.
793 	 * If we are TLSv1 and we get SSLv3, we will respond with TLSv1,
794 	 * This down switching should be handled by a different method.
795 	 * If we are SSLv3, we will respond with SSLv3, even if prompted with
796 	 * TLSv1.
797 	 */
798 	if (S3I(s)->hs.state == SSL3_ST_SR_CLNT_HELLO_A) {
799 		S3I(s)->hs.state = SSL3_ST_SR_CLNT_HELLO_B;
800 	}
801 
802 	s->internal->first_packet = 1;
803 	n = ssl3_get_message(s, SSL3_ST_SR_CLNT_HELLO_B,
804 	    SSL3_ST_SR_CLNT_HELLO_C, SSL3_MT_CLIENT_HELLO,
805 	    SSL3_RT_MAX_PLAIN_LENGTH, &ok);
806 	if (!ok)
807 		return ((int)n);
808 	s->internal->first_packet = 0;
809 
810 	if (n < 0)
811 		goto err;
812 
813 	CBS_init(&cbs, s->internal->init_msg, n);
814 
815 	/* Parse client hello up until the extensions (if any). */
816 	if (!CBS_get_u16(&cbs, &client_version))
817 		goto decode_err;
818 	if (!CBS_get_bytes(&cbs, &client_random, SSL3_RANDOM_SIZE))
819 		goto decode_err;
820 	if (!CBS_get_u8_length_prefixed(&cbs, &session_id))
821 		goto decode_err;
822 	if (CBS_len(&session_id) > SSL3_SESSION_ID_SIZE) {
823 		al = SSL_AD_ILLEGAL_PARAMETER;
824 		SSLerror(s, SSL_R_SSL3_SESSION_ID_TOO_LONG);
825 		goto fatal_err;
826 	}
827 	if (SSL_is_dtls(s)) {
828 		if (!CBS_get_u8_length_prefixed(&cbs, &cookie))
829 			goto decode_err;
830 	}
831 	if (!CBS_get_u16_length_prefixed(&cbs, &cipher_suites))
832 		goto decode_err;
833 	if (!CBS_get_u8_length_prefixed(&cbs, &compression_methods))
834 		goto decode_err;
835 
836 	/*
837 	 * Use version from inside client hello, not from record header.
838 	 * (may differ: see RFC 2246, Appendix E, second paragraph)
839 	 */
840 	if (!ssl_max_shared_version(s, client_version, &shared_version)) {
841 		if ((s->client_version >> 8) == SSL3_VERSION_MAJOR &&
842 		    !tls12_record_layer_write_protected(s->internal->rl)) {
843 			/*
844 			 * Similar to ssl3_get_record, send alert using remote
845 			 * version number.
846 			 */
847 			s->version = s->client_version;
848 		}
849 		SSLerror(s, SSL_R_WRONG_VERSION_NUMBER);
850 		al = SSL_AD_PROTOCOL_VERSION;
851 		goto fatal_err;
852 	}
853 	s->client_version = client_version;
854 	s->version = shared_version;
855 
856 	S3I(s)->hs.negotiated_tls_version = ssl_tls_version(shared_version);
857 	if (S3I(s)->hs.negotiated_tls_version == 0) {
858 		SSLerror(s, ERR_R_INTERNAL_ERROR);
859 		goto err;
860 	}
861 
862 	if ((method = ssl_get_method(shared_version)) == NULL) {
863 		SSLerror(s, ERR_R_INTERNAL_ERROR);
864 		goto err;
865 	}
866 	s->method = method;
867 
868 	/*
869 	 * If we require cookies (DTLS) and this ClientHello does not contain
870 	 * one, just return since we do not want to allocate any memory yet.
871 	 * So check cookie length...
872 	 */
873 	if (SSL_is_dtls(s)) {
874 		if (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) {
875 			if (CBS_len(&cookie) == 0)
876 				return (1);
877 		}
878 	}
879 
880 	if (!CBS_write_bytes(&client_random, s->s3->client_random,
881 	    sizeof(s->s3->client_random), NULL))
882 		goto err;
883 
884 	s->internal->hit = 0;
885 
886 	/*
887 	 * Versions before 0.9.7 always allow clients to resume sessions in
888 	 * renegotiation. 0.9.7 and later allow this by default, but optionally
889 	 * ignore resumption requests with flag
890 	 * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION (it's a new flag
891 	 * rather than a change to default behavior so that applications
892 	 * relying on this for security won't even compile against older
893 	 * library versions).
894 	 *
895 	 * 1.0.1 and later also have a function SSL_renegotiate_abbreviated()
896 	 * to request renegotiation but not a new session (s->internal->new_session
897 	 * remains unset): for servers, this essentially just means that the
898 	 * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION setting will be
899 	 * ignored.
900 	 */
901 	if ((s->internal->new_session && (s->internal->options &
902 	    SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION))) {
903 		if (!ssl_get_new_session(s, 1))
904 			goto err;
905 	} else {
906 		CBS ext_block;
907 
908 		CBS_dup(&cbs, &ext_block);
909 
910 		i = ssl_get_prev_session(s, &session_id, &ext_block, &al);
911 		if (i == 1) { /* previous session */
912 			s->internal->hit = 1;
913 		} else if (i == -1)
914 			goto fatal_err;
915 		else {
916 			/* i == 0 */
917 			if (!ssl_get_new_session(s, 1))
918 				goto err;
919 		}
920 	}
921 
922 	if (SSL_is_dtls(s)) {
923 		/*
924 		 * The ClientHello may contain a cookie even if the HelloVerify
925 		 * message has not been sent - make sure that it does not cause
926 		 * an overflow.
927 		 */
928 		if (CBS_len(&cookie) > sizeof(D1I(s)->rcvd_cookie)) {
929 			al = SSL_AD_DECODE_ERROR;
930 			SSLerror(s, SSL_R_COOKIE_MISMATCH);
931 			goto fatal_err;
932 		}
933 
934 		/* Verify the cookie if appropriate option is set. */
935 		if ((SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) &&
936 		    CBS_len(&cookie) > 0) {
937 			size_t cookie_len;
938 
939 			/* XXX - rcvd_cookie seems to only be used here... */
940 			if (!CBS_write_bytes(&cookie, D1I(s)->rcvd_cookie,
941 			    sizeof(D1I(s)->rcvd_cookie), &cookie_len))
942 				goto err;
943 
944 			if (s->ctx->internal->app_verify_cookie_cb != NULL) {
945 				if (s->ctx->internal->app_verify_cookie_cb(s,
946 				    D1I(s)->rcvd_cookie, cookie_len) == 0) {
947 					al = SSL_AD_HANDSHAKE_FAILURE;
948 					SSLerror(s, SSL_R_COOKIE_MISMATCH);
949 					goto fatal_err;
950 				}
951 				/* else cookie verification succeeded */
952 			/* XXX - can d1->cookie_len > sizeof(rcvd_cookie) ? */
953 			} else if (timingsafe_memcmp(D1I(s)->rcvd_cookie,
954 			    D1I(s)->cookie, D1I(s)->cookie_len) != 0) {
955 				/* default verification */
956 				al = SSL_AD_HANDSHAKE_FAILURE;
957 				SSLerror(s, SSL_R_COOKIE_MISMATCH);
958 				goto fatal_err;
959 			}
960 			cookie_valid = 1;
961 		}
962 	}
963 
964 	/* XXX - This logic seems wrong... */
965 	if (CBS_len(&cipher_suites) == 0 && CBS_len(&session_id) != 0) {
966 		/* we need a cipher if we are not resuming a session */
967 		al = SSL_AD_ILLEGAL_PARAMETER;
968 		SSLerror(s, SSL_R_NO_CIPHERS_SPECIFIED);
969 		goto fatal_err;
970 	}
971 
972 	if (CBS_len(&cipher_suites) > 0) {
973 		if ((ciphers = ssl_bytes_to_cipher_list(s,
974 		    &cipher_suites)) == NULL)
975 			goto err;
976 	}
977 
978 	/* If it is a hit, check that the cipher is in the list */
979 	/* XXX - CBS_len(&cipher_suites) will always be zero here... */
980 	if (s->internal->hit && CBS_len(&cipher_suites) > 0) {
981 		j = 0;
982 		id = s->session->cipher->id;
983 
984 		for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
985 			c = sk_SSL_CIPHER_value(ciphers, i);
986 			if (c->id == id) {
987 				j = 1;
988 				break;
989 			}
990 		}
991 		if (j == 0) {
992 			/*
993 			 * We need to have the cipher in the cipher
994 			 * list if we are asked to reuse it
995 			 */
996 			al = SSL_AD_ILLEGAL_PARAMETER;
997 			SSLerror(s, SSL_R_REQUIRED_CIPHER_MISSING);
998 			goto fatal_err;
999 		}
1000 	}
1001 
1002 	comp_null = 0;
1003 	while (CBS_len(&compression_methods) > 0) {
1004 		if (!CBS_get_u8(&compression_methods, &comp_method))
1005 			goto decode_err;
1006 		if (comp_method == 0)
1007 			comp_null = 1;
1008 	}
1009 	if (comp_null == 0) {
1010 		al = SSL_AD_DECODE_ERROR;
1011 		SSLerror(s, SSL_R_NO_COMPRESSION_SPECIFIED);
1012 		goto fatal_err;
1013 	}
1014 
1015 	if (!tlsext_server_parse(s, SSL_TLSEXT_MSG_CH, &cbs, &al)) {
1016 		SSLerror(s, SSL_R_PARSE_TLSEXT);
1017 		goto fatal_err;
1018 	}
1019 
1020 	if (!S3I(s)->renegotiate_seen && s->internal->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 (S3I(s)->hs.our_max_tls_version >= TLS1_2_VERSION &&
1040 	    S3I(s)->hs.negotiated_tls_version < S3I(s)->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 (S3I(s)->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->internal->hit && s->internal->tls_session_secret_cb) {
1061 		SSL_CIPHER *pref_cipher = NULL;
1062 
1063 		s->session->master_key_length = sizeof(s->session->master_key);
1064 		if (s->internal->tls_session_secret_cb(s, s->session->master_key,
1065 		    &s->session->master_key_length, ciphers, &pref_cipher,
1066 		    s->internal->tls_session_secret_cb_arg)) {
1067 			s->internal->hit = 1;
1068 			s->session->ciphers = ciphers;
1069 			s->session->verify_result = X509_V_OK;
1070 
1071 			ciphers = NULL;
1072 
1073 			/* check if some cipher was preferred by call back */
1074 			pref_cipher = pref_cipher ? pref_cipher :
1075 			    ssl3_choose_cipher(s, s->session->ciphers,
1076 			    SSL_get_ciphers(s));
1077 			if (pref_cipher == NULL) {
1078 				al = SSL_AD_HANDSHAKE_FAILURE;
1079 				SSLerror(s, SSL_R_NO_SHARED_CIPHER);
1080 				goto fatal_err;
1081 			}
1082 
1083 			s->session->cipher = pref_cipher;
1084 
1085 			sk_SSL_CIPHER_free(s->cipher_list);
1086 			s->cipher_list = sk_SSL_CIPHER_dup(s->session->ciphers);
1087 		}
1088 	}
1089 
1090 	/*
1091 	 * Given s->session->ciphers and SSL_get_ciphers, we must
1092 	 * pick a cipher
1093 	 */
1094 
1095 	if (!s->internal->hit) {
1096 		sk_SSL_CIPHER_free(s->session->ciphers);
1097 		s->session->ciphers = ciphers;
1098 		if (ciphers == NULL) {
1099 			al = SSL_AD_ILLEGAL_PARAMETER;
1100 			SSLerror(s, SSL_R_NO_CIPHERS_PASSED);
1101 			goto fatal_err;
1102 		}
1103 		ciphers = NULL;
1104 		c = ssl3_choose_cipher(s, s->session->ciphers,
1105 		SSL_get_ciphers(s));
1106 
1107 		if (c == NULL) {
1108 			al = SSL_AD_HANDSHAKE_FAILURE;
1109 			SSLerror(s, SSL_R_NO_SHARED_CIPHER);
1110 			goto fatal_err;
1111 		}
1112 		S3I(s)->hs.cipher = c;
1113 	} else {
1114 		S3I(s)->hs.cipher = s->session->cipher;
1115 	}
1116 
1117 	if (!tls1_transcript_hash_init(s))
1118 		goto err;
1119 
1120 	alg_k = S3I(s)->hs.cipher->algorithm_mkey;
1121 	if (!(SSL_USE_SIGALGS(s) || (alg_k & SSL_kGOST)) ||
1122 	    !(s->verify_mode & SSL_VERIFY_PEER))
1123 		tls1_transcript_free(s);
1124 
1125 	/*
1126 	 * We now have the following setup.
1127 	 * client_random
1128 	 * cipher_list		- our prefered list of ciphers
1129 	 * ciphers		- the clients prefered list of ciphers
1130 	 * compression		- basically ignored right now
1131 	 * ssl version is set	- sslv3
1132 	 * s->session		- The ssl session has been setup.
1133 	 * s->internal->hit		- session reuse flag
1134 	 * s->hs.cipher	- the new cipher to use.
1135 	 */
1136 
1137 	/* Handles TLS extensions that we couldn't check earlier */
1138 	if (ssl_check_clienthello_tlsext_late(s) <= 0) {
1139 		SSLerror(s, SSL_R_CLIENTHELLO_TLSEXT);
1140 		goto err;
1141 	}
1142 
1143 	ret = cookie_valid ? 2 : 1;
1144 
1145 	if (0) {
1146  decode_err:
1147 		al = SSL_AD_DECODE_ERROR;
1148 		SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
1149  fatal_err:
1150 		ssl3_send_alert(s, SSL3_AL_FATAL, al);
1151 	}
1152  err:
1153 	sk_SSL_CIPHER_free(ciphers);
1154 
1155 	return (ret);
1156 }
1157 
1158 int
1159 ssl3_send_dtls_hello_verify_request(SSL *s)
1160 {
1161 	CBB cbb, verify, cookie;
1162 
1163 	memset(&cbb, 0, sizeof(cbb));
1164 
1165 	if (S3I(s)->hs.state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
1166 		if (s->ctx->internal->app_gen_cookie_cb == NULL ||
1167 		    s->ctx->internal->app_gen_cookie_cb(s, D1I(s)->cookie,
1168 			&(D1I(s)->cookie_len)) == 0) {
1169 			SSLerror(s, ERR_R_INTERNAL_ERROR);
1170 			return 0;
1171 		}
1172 
1173 		/*
1174 		 * Per RFC 6347 section 4.2.1, the HelloVerifyRequest should
1175 		 * always contain DTLSv1.0 regardless of the version that is
1176 		 * going to be negotiated.
1177 		 */
1178 		if (!ssl3_handshake_msg_start(s, &cbb, &verify,
1179 		    DTLS1_MT_HELLO_VERIFY_REQUEST))
1180 			goto err;
1181 		if (!CBB_add_u16(&verify, DTLS1_VERSION))
1182 			goto err;
1183 		if (!CBB_add_u8_length_prefixed(&verify, &cookie))
1184 			goto err;
1185 		if (!CBB_add_bytes(&cookie, D1I(s)->cookie, D1I(s)->cookie_len))
1186 			goto err;
1187 		if (!ssl3_handshake_msg_finish(s, &cbb))
1188 			goto err;
1189 
1190 		S3I(s)->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
1191 	}
1192 
1193 	/* S3I(s)->hs.state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
1194 	return (ssl3_handshake_write(s));
1195 
1196  err:
1197 	CBB_cleanup(&cbb);
1198 
1199 	return (-1);
1200 }
1201 
1202 int
1203 ssl3_send_server_hello(SSL *s)
1204 {
1205 	CBB cbb, server_hello, session_id;
1206 	size_t sl;
1207 
1208 	memset(&cbb, 0, sizeof(cbb));
1209 
1210 	if (S3I(s)->hs.state == SSL3_ST_SW_SRVR_HELLO_A) {
1211 		if (!ssl3_handshake_msg_start(s, &cbb, &server_hello,
1212 		    SSL3_MT_SERVER_HELLO))
1213 			goto err;
1214 
1215 		if (!CBB_add_u16(&server_hello, s->version))
1216 			goto err;
1217 		if (!CBB_add_bytes(&server_hello, s->s3->server_random,
1218 		    sizeof(s->s3->server_random)))
1219 			goto err;
1220 
1221 		/*
1222 		 * There are several cases for the session ID to send
1223 		 * back in the server hello:
1224 		 *
1225 		 * - For session reuse from the session cache,
1226 		 *   we send back the old session ID.
1227 		 * - If stateless session reuse (using a session ticket)
1228 		 *   is successful, we send back the client's "session ID"
1229 		 *   (which doesn't actually identify the session).
1230 		 * - If it is a new session, we send back the new
1231 		 *   session ID.
1232 		 * - However, if we want the new session to be single-use,
1233 		 *   we send back a 0-length session ID.
1234 		 *
1235 		 * s->internal->hit is non-zero in either case of session reuse,
1236 		 * so the following won't overwrite an ID that we're supposed
1237 		 * to send back.
1238 		 */
1239 		if (!(s->ctx->internal->session_cache_mode & SSL_SESS_CACHE_SERVER)
1240 		    && !s->internal->hit)
1241 			s->session->session_id_length = 0;
1242 
1243 		sl = s->session->session_id_length;
1244 		if (sl > sizeof(s->session->session_id)) {
1245 			SSLerror(s, ERR_R_INTERNAL_ERROR);
1246 			goto err;
1247 		}
1248 		if (!CBB_add_u8_length_prefixed(&server_hello, &session_id))
1249 			goto err;
1250 		if (!CBB_add_bytes(&session_id, s->session->session_id, sl))
1251 			goto err;
1252 
1253 		/* Cipher suite. */
1254 		if (!CBB_add_u16(&server_hello,
1255 		    ssl3_cipher_get_value(S3I(s)->hs.cipher)))
1256 			goto err;
1257 
1258 		/* Compression method (null). */
1259 		if (!CBB_add_u8(&server_hello, 0))
1260 			goto err;
1261 
1262 		/* TLS extensions */
1263 		if (!tlsext_server_build(s, SSL_TLSEXT_MSG_SH, &server_hello)) {
1264 			SSLerror(s, ERR_R_INTERNAL_ERROR);
1265 			goto err;
1266 		}
1267 
1268 		if (!ssl3_handshake_msg_finish(s, &cbb))
1269 			goto err;
1270 	}
1271 
1272 	/* SSL3_ST_SW_SRVR_HELLO_B */
1273 	return (ssl3_handshake_write(s));
1274 
1275  err:
1276 	CBB_cleanup(&cbb);
1277 
1278 	return (-1);
1279 }
1280 
1281 int
1282 ssl3_send_server_done(SSL *s)
1283 {
1284 	CBB cbb, done;
1285 
1286 	memset(&cbb, 0, sizeof(cbb));
1287 
1288 	if (S3I(s)->hs.state == SSL3_ST_SW_SRVR_DONE_A) {
1289 		if (!ssl3_handshake_msg_start(s, &cbb, &done,
1290 		    SSL3_MT_SERVER_DONE))
1291 			goto err;
1292 		if (!ssl3_handshake_msg_finish(s, &cbb))
1293 			goto err;
1294 
1295 		S3I(s)->hs.state = SSL3_ST_SW_SRVR_DONE_B;
1296 	}
1297 
1298 	/* SSL3_ST_SW_SRVR_DONE_B */
1299 	return (ssl3_handshake_write(s));
1300 
1301  err:
1302 	CBB_cleanup(&cbb);
1303 
1304 	return (-1);
1305 }
1306 
1307 static int
1308 ssl3_send_server_kex_dhe(SSL *s, CBB *cbb)
1309 {
1310 	CBB dh_p, dh_g, dh_Ys;
1311 	DH *dh = NULL, *dhp;
1312 	unsigned char *data;
1313 	int al;
1314 
1315 	if (s->cert->dh_tmp_auto != 0) {
1316 		if ((dhp = ssl_get_auto_dh(s)) == NULL) {
1317 			al = SSL_AD_INTERNAL_ERROR;
1318 			SSLerror(s, ERR_R_INTERNAL_ERROR);
1319 			goto fatal_err;
1320 		}
1321 	} else
1322 		dhp = s->cert->dh_tmp;
1323 
1324 	if (dhp == NULL && s->cert->dh_tmp_cb != NULL)
1325 		dhp = s->cert->dh_tmp_cb(s, 0,
1326 		    SSL_C_PKEYLENGTH(S3I(s)->hs.cipher));
1327 
1328 	if (dhp == NULL) {
1329 		al = SSL_AD_HANDSHAKE_FAILURE;
1330 		SSLerror(s, SSL_R_MISSING_TMP_DH_KEY);
1331 		goto fatal_err;
1332 	}
1333 
1334 	if (S3I(s)->tmp.dh != NULL) {
1335 		SSLerror(s, ERR_R_INTERNAL_ERROR);
1336 		goto err;
1337 	}
1338 
1339 	if (s->cert->dh_tmp_auto != 0) {
1340 		dh = dhp;
1341 	} else if ((dh = DHparams_dup(dhp)) == NULL) {
1342 		SSLerror(s, ERR_R_DH_LIB);
1343 		goto err;
1344 	}
1345 	S3I(s)->tmp.dh = dh;
1346 	if (!DH_generate_key(dh)) {
1347 		SSLerror(s, ERR_R_DH_LIB);
1348 		goto err;
1349 	}
1350 
1351 	/*
1352 	 * Serialize the DH parameters and public key.
1353 	 */
1354 	if (!CBB_add_u16_length_prefixed(cbb, &dh_p))
1355 		goto err;
1356 	if (!CBB_add_space(&dh_p, &data, BN_num_bytes(dh->p)))
1357 		goto err;
1358 	BN_bn2bin(dh->p, data);
1359 
1360 	if (!CBB_add_u16_length_prefixed(cbb, &dh_g))
1361 		goto err;
1362 	if (!CBB_add_space(&dh_g, &data, BN_num_bytes(dh->g)))
1363 		goto err;
1364 	BN_bn2bin(dh->g, data);
1365 
1366 	if (!CBB_add_u16_length_prefixed(cbb, &dh_Ys))
1367 		goto err;
1368 	if (!CBB_add_space(&dh_Ys, &data, BN_num_bytes(dh->pub_key)))
1369 		goto err;
1370 	BN_bn2bin(dh->pub_key, data);
1371 
1372 	if (!CBB_flush(cbb))
1373 		goto err;
1374 
1375 	return (1);
1376 
1377  fatal_err:
1378 	ssl3_send_alert(s, SSL3_AL_FATAL, al);
1379  err:
1380 	return (-1);
1381 }
1382 
1383 static int
1384 ssl3_send_server_kex_ecdhe_ecp(SSL *s, int nid, CBB *cbb)
1385 {
1386 	uint16_t curve_id;
1387 	EC_KEY *ecdh;
1388 	CBB ecpoint;
1389 	int al;
1390 
1391 	/*
1392 	 * Only named curves are supported in ECDH ephemeral key exchanges.
1393 	 * For supported named curves, curve_id is non-zero.
1394 	 */
1395 	if ((curve_id = tls1_ec_nid2curve_id(nid)) == 0) {
1396 		SSLerror(s, SSL_R_UNSUPPORTED_ELLIPTIC_CURVE);
1397 		goto err;
1398 	}
1399 
1400 	if (S3I(s)->tmp.ecdh != NULL) {
1401 		SSLerror(s, ERR_R_INTERNAL_ERROR);
1402 		goto err;
1403 	}
1404 
1405 	if ((S3I(s)->tmp.ecdh = EC_KEY_new()) == NULL) {
1406 		al = SSL_AD_HANDSHAKE_FAILURE;
1407 		SSLerror(s, SSL_R_MISSING_TMP_ECDH_KEY);
1408 		goto fatal_err;
1409 	}
1410 	S3I(s)->tmp.ecdh_nid = nid;
1411 	ecdh = S3I(s)->tmp.ecdh;
1412 
1413 	if (!ssl_kex_generate_ecdhe_ecp(ecdh, nid))
1414 		goto err;
1415 
1416 	/*
1417 	 * Encode the public key.
1418 	 *
1419 	 * Only named curves are supported in ECDH ephemeral key exchanges.
1420 	 * In this case the ServerKeyExchange message has:
1421 	 * [1 byte CurveType], [2 byte CurveName]
1422 	 * [1 byte length of encoded point], followed by
1423 	 * the actual encoded point itself.
1424 	 */
1425 	if (!CBB_add_u8(cbb, NAMED_CURVE_TYPE))
1426 		goto err;
1427 	if (!CBB_add_u16(cbb, curve_id))
1428 		goto err;
1429 	if (!CBB_add_u8_length_prefixed(cbb, &ecpoint))
1430 		goto err;
1431 	if (!ssl_kex_public_ecdhe_ecp(ecdh, &ecpoint))
1432 		goto err;
1433 	if (!CBB_flush(cbb))
1434 		goto err;
1435 
1436 	return (1);
1437 
1438  fatal_err:
1439 	ssl3_send_alert(s, SSL3_AL_FATAL, al);
1440  err:
1441 	return (-1);
1442 }
1443 
1444 static int
1445 ssl3_send_server_kex_ecdhe_ecx(SSL *s, int nid, CBB *cbb)
1446 {
1447 	uint8_t *public_key = NULL, *private_key = NULL;
1448 	uint16_t curve_id;
1449 	CBB ecpoint;
1450 	int ret = -1;
1451 
1452 	/* Generate an X25519 key pair. */
1453 	if (S3I(s)->tmp.x25519 != NULL) {
1454 		SSLerror(s, ERR_R_INTERNAL_ERROR);
1455 		goto err;
1456 	}
1457 	if ((private_key = malloc(X25519_KEY_LENGTH)) == NULL)
1458 		goto err;
1459 	if ((public_key = malloc(X25519_KEY_LENGTH)) == NULL)
1460 		goto err;
1461 	X25519_keypair(public_key, private_key);
1462 
1463 	/* Serialize public key. */
1464 	if ((curve_id = tls1_ec_nid2curve_id(nid)) == 0) {
1465 		SSLerror(s, SSL_R_UNSUPPORTED_ELLIPTIC_CURVE);
1466 		goto err;
1467 	}
1468 
1469 	if (!CBB_add_u8(cbb, NAMED_CURVE_TYPE))
1470 		goto err;
1471 	if (!CBB_add_u16(cbb, curve_id))
1472 		goto err;
1473 	if (!CBB_add_u8_length_prefixed(cbb, &ecpoint))
1474 		goto err;
1475 	if (!CBB_add_bytes(&ecpoint, public_key, X25519_KEY_LENGTH))
1476 		goto err;
1477 	if (!CBB_flush(cbb))
1478 		goto err;
1479 
1480 	S3I(s)->tmp.x25519 = private_key;
1481 	private_key = NULL;
1482 	ret = 1;
1483 
1484  err:
1485 	free(public_key);
1486 	freezero(private_key, X25519_KEY_LENGTH);
1487 
1488 	return (ret);
1489 }
1490 
1491 static int
1492 ssl3_send_server_kex_ecdhe(SSL *s, CBB *cbb)
1493 {
1494 	int nid;
1495 
1496 	nid = tls1_get_shared_curve(s);
1497 
1498 	if (nid == NID_X25519)
1499 		return ssl3_send_server_kex_ecdhe_ecx(s, nid, cbb);
1500 
1501 	return ssl3_send_server_kex_ecdhe_ecp(s, nid, cbb);
1502 }
1503 
1504 int
1505 ssl3_send_server_key_exchange(SSL *s)
1506 {
1507 	CBB cbb, cbb_params, cbb_signature, server_kex;
1508 	const struct ssl_sigalg *sigalg = NULL;
1509 	unsigned char *signature = NULL;
1510 	size_t signature_len = 0;
1511 	unsigned char *params = NULL;
1512 	size_t params_len;
1513 	const EVP_MD *md = NULL;
1514 	unsigned long type;
1515 	EVP_MD_CTX md_ctx;
1516 	EVP_PKEY_CTX *pctx;
1517 	EVP_PKEY *pkey;
1518 	int al;
1519 
1520 	memset(&cbb, 0, sizeof(cbb));
1521 	memset(&cbb_params, 0, sizeof(cbb_params));
1522 
1523 	EVP_MD_CTX_init(&md_ctx);
1524 
1525 	if (S3I(s)->hs.state == SSL3_ST_SW_KEY_EXCH_A) {
1526 
1527 		if (!ssl3_handshake_msg_start(s, &cbb, &server_kex,
1528 		    SSL3_MT_SERVER_KEY_EXCHANGE))
1529 			goto err;
1530 
1531 		if (!CBB_init(&cbb_params, 0))
1532 			goto err;
1533 
1534 		type = S3I(s)->hs.cipher->algorithm_mkey;
1535 		if (type & SSL_kDHE) {
1536 			if (ssl3_send_server_kex_dhe(s, &cbb_params) != 1)
1537 				goto err;
1538 		} else if (type & SSL_kECDHE) {
1539 			if (ssl3_send_server_kex_ecdhe(s, &cbb_params) != 1)
1540 				goto err;
1541 		} else {
1542 			al = SSL_AD_HANDSHAKE_FAILURE;
1543 			SSLerror(s, SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
1544 			goto fatal_err;
1545 		}
1546 
1547 		if (!CBB_finish(&cbb_params, &params, &params_len))
1548 			goto err;
1549 
1550 		if (!CBB_add_bytes(&server_kex, params, params_len))
1551 			goto err;
1552 
1553 		/* Add signature unless anonymous. */
1554 		if (!(S3I(s)->hs.cipher->algorithm_auth & SSL_aNULL)) {
1555 			if ((pkey = ssl_get_sign_pkey(s, S3I(s)->hs.cipher,
1556 			    &md, &sigalg)) == NULL) {
1557 				al = SSL_AD_DECODE_ERROR;
1558 				goto fatal_err;
1559 			}
1560 			S3I(s)->hs.our_sigalg = sigalg;
1561 
1562 			/* Send signature algorithm. */
1563 			if (SSL_USE_SIGALGS(s)) {
1564 				if (!CBB_add_u16(&server_kex, sigalg->value)) {
1565 					al = SSL_AD_INTERNAL_ERROR;
1566 					SSLerror(s, ERR_R_INTERNAL_ERROR);
1567 					goto fatal_err;
1568 				}
1569 			}
1570 
1571 			if (!EVP_DigestSignInit(&md_ctx, &pctx, md, NULL, pkey)) {
1572 				SSLerror(s, ERR_R_EVP_LIB);
1573 				goto err;
1574 			}
1575 			if ((sigalg->flags & SIGALG_FLAG_RSA_PSS) &&
1576 			    (!EVP_PKEY_CTX_set_rsa_padding(pctx,
1577 			    RSA_PKCS1_PSS_PADDING) ||
1578 			    !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1))) {
1579 				SSLerror(s, ERR_R_EVP_LIB);
1580 				goto err;
1581 			}
1582 			if (!EVP_DigestSignUpdate(&md_ctx, s->s3->client_random,
1583 			    SSL3_RANDOM_SIZE)) {
1584 				SSLerror(s, ERR_R_EVP_LIB);
1585 				goto err;
1586 			}
1587 			if (!EVP_DigestSignUpdate(&md_ctx, s->s3->server_random,
1588 			    SSL3_RANDOM_SIZE)) {
1589 				SSLerror(s, ERR_R_EVP_LIB);
1590 				goto err;
1591 			}
1592 			if (!EVP_DigestSignUpdate(&md_ctx, params, params_len)) {
1593 				SSLerror(s, ERR_R_EVP_LIB);
1594 				goto err;
1595 			}
1596 			if (!EVP_DigestSignFinal(&md_ctx, NULL, &signature_len) ||
1597 			    !signature_len) {
1598 				SSLerror(s, ERR_R_EVP_LIB);
1599 				goto err;
1600 			}
1601 			if ((signature = calloc(1, signature_len)) == NULL) {
1602 				SSLerror(s, ERR_R_MALLOC_FAILURE);
1603 				goto err;
1604 			}
1605 			if (!EVP_DigestSignFinal(&md_ctx, signature, &signature_len)) {
1606 				SSLerror(s, ERR_R_EVP_LIB);
1607 				goto err;
1608 			}
1609 
1610 			if (!CBB_add_u16_length_prefixed(&server_kex,
1611 			    &cbb_signature))
1612 				goto err;
1613 			if (!CBB_add_bytes(&cbb_signature, signature,
1614 			    signature_len))
1615 				goto err;
1616 		}
1617 
1618 		if (!ssl3_handshake_msg_finish(s, &cbb))
1619 			goto err;
1620 
1621 		S3I(s)->hs.state = SSL3_ST_SW_KEY_EXCH_B;
1622 	}
1623 
1624 	EVP_MD_CTX_cleanup(&md_ctx);
1625 	free(params);
1626 	free(signature);
1627 
1628 	return (ssl3_handshake_write(s));
1629 
1630  fatal_err:
1631 	ssl3_send_alert(s, SSL3_AL_FATAL, al);
1632  err:
1633 	CBB_cleanup(&cbb_params);
1634 	CBB_cleanup(&cbb);
1635 	EVP_MD_CTX_cleanup(&md_ctx);
1636 	free(params);
1637 	free(signature);
1638 
1639 	return (-1);
1640 }
1641 
1642 int
1643 ssl3_send_certificate_request(SSL *s)
1644 {
1645 	CBB cbb, cert_request, cert_types, sigalgs, cert_auth, dn;
1646 	STACK_OF(X509_NAME) *sk = NULL;
1647 	X509_NAME *name;
1648 	int i;
1649 
1650 	/*
1651 	 * Certificate Request - RFC 5246 section 7.4.4.
1652 	 */
1653 
1654 	memset(&cbb, 0, sizeof(cbb));
1655 
1656 	if (S3I(s)->hs.state == SSL3_ST_SW_CERT_REQ_A) {
1657 		if (!ssl3_handshake_msg_start(s, &cbb, &cert_request,
1658 		    SSL3_MT_CERTIFICATE_REQUEST))
1659 			goto err;
1660 
1661 		if (!CBB_add_u8_length_prefixed(&cert_request, &cert_types))
1662 			goto err;
1663 		if (!ssl3_get_req_cert_types(s, &cert_types))
1664 			goto err;
1665 
1666 		if (SSL_USE_SIGALGS(s)) {
1667 			if (!CBB_add_u16_length_prefixed(&cert_request,
1668 			    &sigalgs))
1669 				goto err;
1670 			if (!ssl_sigalgs_build(
1671 			    S3I(s)->hs.negotiated_tls_version, &sigalgs))
1672 				goto err;
1673 		}
1674 
1675 		if (!CBB_add_u16_length_prefixed(&cert_request, &cert_auth))
1676 			goto err;
1677 
1678 		sk = SSL_get_client_CA_list(s);
1679 		for (i = 0; i < sk_X509_NAME_num(sk); i++) {
1680 			unsigned char *name_data;
1681 			size_t name_len;
1682 
1683 			name = sk_X509_NAME_value(sk, i);
1684 			name_len = i2d_X509_NAME(name, NULL);
1685 
1686 			if (!CBB_add_u16_length_prefixed(&cert_auth, &dn))
1687 				goto err;
1688 			if (!CBB_add_space(&dn, &name_data, name_len))
1689 				goto err;
1690 			if (i2d_X509_NAME(name, &name_data) != name_len)
1691 				goto err;
1692 		}
1693 
1694 		if (!ssl3_handshake_msg_finish(s, &cbb))
1695 			goto err;
1696 
1697 		S3I(s)->hs.state = SSL3_ST_SW_CERT_REQ_B;
1698 	}
1699 
1700 	/* SSL3_ST_SW_CERT_REQ_B */
1701 	return (ssl3_handshake_write(s));
1702 
1703  err:
1704 	CBB_cleanup(&cbb);
1705 
1706 	return (-1);
1707 }
1708 
1709 static int
1710 ssl3_get_client_kex_rsa(SSL *s, CBS *cbs)
1711 {
1712 	unsigned char fakekey[SSL_MAX_MASTER_KEY_LENGTH];
1713 	unsigned char *pms = NULL;
1714 	unsigned char *p;
1715 	size_t pms_len = 0;
1716 	EVP_PKEY *pkey = NULL;
1717 	RSA *rsa = NULL;
1718 	CBS enc_pms;
1719 	int decrypt_len;
1720 	int al = -1;
1721 
1722 	arc4random_buf(fakekey, sizeof(fakekey));
1723 
1724 	/* XXX - peer max protocol version. */
1725 	fakekey[0] = s->client_version >> 8;
1726 	fakekey[1] = s->client_version & 0xff;
1727 
1728 	pkey = s->cert->pkeys[SSL_PKEY_RSA].privatekey;
1729 	if ((pkey == NULL) || (pkey->type != EVP_PKEY_RSA) ||
1730 	    (pkey->pkey.rsa == NULL)) {
1731 		al = SSL_AD_HANDSHAKE_FAILURE;
1732 		SSLerror(s, SSL_R_MISSING_RSA_CERTIFICATE);
1733 		goto fatal_err;
1734 	}
1735 	rsa = pkey->pkey.rsa;
1736 
1737 	pms_len = RSA_size(rsa);
1738 	if (pms_len < SSL_MAX_MASTER_KEY_LENGTH)
1739 		goto err;
1740 	if ((pms = malloc(pms_len)) == NULL)
1741 		goto err;
1742 	p = pms;
1743 
1744 	if (!CBS_get_u16_length_prefixed(cbs, &enc_pms))
1745 		goto decode_err;
1746 	if (CBS_len(cbs) != 0 || CBS_len(&enc_pms) != RSA_size(rsa)) {
1747 		SSLerror(s, SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG);
1748 		goto err;
1749 	}
1750 
1751 	decrypt_len = RSA_private_decrypt(CBS_len(&enc_pms), CBS_data(&enc_pms),
1752 	    pms, rsa, RSA_PKCS1_PADDING);
1753 
1754 	ERR_clear_error();
1755 
1756 	if (decrypt_len != SSL_MAX_MASTER_KEY_LENGTH) {
1757 		al = SSL_AD_DECODE_ERROR;
1758 		/* SSLerror(s, SSL_R_BAD_RSA_DECRYPT); */
1759 	}
1760 
1761 	/* XXX - peer max version. */
1762 	if ((al == -1) && !((pms[0] == (s->client_version >> 8)) &&
1763 	    (pms[1] == (s->client_version & 0xff)))) {
1764 		/*
1765 		 * The premaster secret must contain the same version number
1766 		 * as the ClientHello to detect version rollback attacks
1767 		 * (strangely, the protocol does not offer such protection for
1768 		 * DH ciphersuites).
1769 		 *
1770 		 * The Klima-Pokorny-Rosa extension of Bleichenbacher's attack
1771 		 * (http://eprint.iacr.org/2003/052/) exploits the version
1772 		 * number check as a "bad version oracle" -- an alert would
1773 		 * reveal that the plaintext corresponding to some ciphertext
1774 		 * made up by the adversary is properly formatted except that
1775 		 * the version number is wrong. To avoid such attacks, we should
1776 		 * treat this just like any other decryption error.
1777 		 */
1778 		al = SSL_AD_DECODE_ERROR;
1779 		/* SSLerror(s, SSL_R_BAD_PROTOCOL_VERSION_NUMBER); */
1780 	}
1781 
1782 	if (al != -1) {
1783 		/*
1784 		 * Some decryption failure -- use random value instead
1785 		 * as countermeasure against Bleichenbacher's attack
1786 		 * on PKCS #1 v1.5 RSA padding (see RFC 2246,
1787 		 * section 7.4.7.1).
1788 		 */
1789 		p = fakekey;
1790 	}
1791 
1792 	if (!tls12_derive_master_secret(s, p, SSL_MAX_MASTER_KEY_LENGTH))
1793 		goto err;
1794 
1795 	freezero(pms, pms_len);
1796 
1797 	return (1);
1798 
1799  decode_err:
1800 	al = SSL_AD_DECODE_ERROR;
1801 	SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
1802  fatal_err:
1803 	ssl3_send_alert(s, SSL3_AL_FATAL, al);
1804  err:
1805 	freezero(pms, pms_len);
1806 
1807 	return (-1);
1808 }
1809 
1810 static int
1811 ssl3_get_client_kex_dhe(SSL *s, CBS *cbs)
1812 {
1813 	int key_size = 0;
1814 	int key_is_invalid, key_len, al;
1815 	unsigned char *key = NULL;
1816 	BIGNUM *bn = NULL;
1817 	CBS dh_Yc;
1818 	DH *dh;
1819 
1820 	if (!CBS_get_u16_length_prefixed(cbs, &dh_Yc))
1821 		goto decode_err;
1822 	if (CBS_len(cbs) != 0)
1823 		goto decode_err;
1824 
1825 	if (S3I(s)->tmp.dh == NULL) {
1826 		al = SSL_AD_HANDSHAKE_FAILURE;
1827 		SSLerror(s, SSL_R_MISSING_TMP_DH_KEY);
1828 		goto fatal_err;
1829 	}
1830 	dh = S3I(s)->tmp.dh;
1831 
1832 	if ((bn = BN_bin2bn(CBS_data(&dh_Yc), CBS_len(&dh_Yc), NULL)) == NULL) {
1833 		SSLerror(s, SSL_R_BN_LIB);
1834 		goto err;
1835 	}
1836 
1837 	if ((key_size = DH_size(dh)) <= 0) {
1838 		SSLerror(s, ERR_R_DH_LIB);
1839 		goto err;
1840 	}
1841 	if ((key = malloc(key_size)) == NULL) {
1842 		SSLerror(s, ERR_R_MALLOC_FAILURE);
1843 		goto err;
1844 	}
1845 	if (!DH_check_pub_key(dh, bn, &key_is_invalid)) {
1846 		al = SSL_AD_INTERNAL_ERROR;
1847 		SSLerror(s, ERR_R_DH_LIB);
1848 		goto fatal_err;
1849 	}
1850 	if (key_is_invalid) {
1851 		al = SSL_AD_ILLEGAL_PARAMETER;
1852 		SSLerror(s, ERR_R_DH_LIB);
1853 		goto fatal_err;
1854 	}
1855 	if ((key_len = DH_compute_key(key, bn, dh)) <= 0) {
1856 		al = SSL_AD_INTERNAL_ERROR;
1857 		SSLerror(s, ERR_R_DH_LIB);
1858 		goto fatal_err;
1859 	}
1860 
1861 	if (!tls12_derive_master_secret(s, key, key_len))
1862 		goto err;
1863 
1864 	DH_free(S3I(s)->tmp.dh);
1865 	S3I(s)->tmp.dh = NULL;
1866 
1867 	freezero(key, key_size);
1868 	BN_clear_free(bn);
1869 
1870 	return (1);
1871 
1872  decode_err:
1873 	al = SSL_AD_DECODE_ERROR;
1874 	SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
1875  fatal_err:
1876 	ssl3_send_alert(s, SSL3_AL_FATAL, al);
1877  err:
1878 	freezero(key, key_size);
1879 	BN_clear_free(bn);
1880 
1881 	return (-1);
1882 }
1883 
1884 static int
1885 ssl3_get_client_kex_ecdhe_ecp(SSL *s, CBS *cbs)
1886 {
1887 	uint8_t *key = NULL;
1888 	size_t key_len = 0;
1889 	EC_KEY *ecdh_peer = NULL;
1890 	EC_KEY *ecdh;
1891 	CBS public;
1892 	int ret = -1;
1893 
1894 	/*
1895 	 * Use the ephemeral values we saved when generating the
1896 	 * ServerKeyExchange message.
1897 	 */
1898 	if ((ecdh = S3I(s)->tmp.ecdh) == NULL) {
1899 		SSLerror(s, ERR_R_INTERNAL_ERROR);
1900 		goto err;
1901 	}
1902 
1903 	/*
1904 	 * Get client's public key from encoded point in the ClientKeyExchange
1905 	 * message.
1906 	 */
1907 	if (!CBS_get_u8_length_prefixed(cbs, &public))
1908 		goto err;
1909 	if (CBS_len(cbs) != 0)
1910 		goto err;
1911 
1912 	if ((ecdh_peer = EC_KEY_new()) == NULL)
1913 		goto err;
1914 
1915 	if (!ssl_kex_peer_public_ecdhe_ecp(ecdh_peer, S3I(s)->tmp.ecdh_nid,
1916 	    &public))
1917 		goto err;
1918 
1919 	/* Derive the shared secret and compute master secret. */
1920 	if (!ssl_kex_derive_ecdhe_ecp(ecdh, ecdh_peer, &key, &key_len))
1921 		goto err;
1922 	if (!tls12_derive_master_secret(s, key, key_len))
1923 		goto err;
1924 
1925 	EC_KEY_free(S3I(s)->tmp.ecdh);
1926 	S3I(s)->tmp.ecdh = NULL;
1927 	S3I(s)->tmp.ecdh_nid = NID_undef;
1928 
1929 	ret = 1;
1930 
1931  err:
1932 	freezero(key, key_len);
1933 	EC_KEY_free(ecdh_peer);
1934 
1935 	return (ret);
1936 }
1937 
1938 static int
1939 ssl3_get_client_kex_ecdhe_ecx(SSL *s, CBS *cbs)
1940 {
1941 	uint8_t *shared_key = NULL;
1942 	CBS ecpoint;
1943 	int ret = -1;
1944 
1945 	if (!CBS_get_u8_length_prefixed(cbs, &ecpoint))
1946 		goto err;
1947 	if (CBS_len(cbs) != 0)
1948 		goto err;
1949 	if (CBS_len(&ecpoint) != X25519_KEY_LENGTH)
1950 		goto err;
1951 
1952 	if ((shared_key = malloc(X25519_KEY_LENGTH)) == NULL)
1953 		goto err;
1954 	if (!X25519(shared_key, S3I(s)->tmp.x25519, CBS_data(&ecpoint)))
1955 		goto err;
1956 
1957 	freezero(S3I(s)->tmp.x25519, X25519_KEY_LENGTH);
1958 	S3I(s)->tmp.x25519 = NULL;
1959 
1960 	if (!tls12_derive_master_secret(s, shared_key, X25519_KEY_LENGTH))
1961 		goto err;
1962 
1963 	ret = 1;
1964 
1965  err:
1966 	freezero(shared_key, X25519_KEY_LENGTH);
1967 
1968 	return (ret);
1969 }
1970 
1971 static int
1972 ssl3_get_client_kex_ecdhe(SSL *s, CBS *cbs)
1973 {
1974 	if (S3I(s)->tmp.x25519 != NULL)
1975 		return ssl3_get_client_kex_ecdhe_ecx(s, cbs);
1976 
1977 	return ssl3_get_client_kex_ecdhe_ecp(s, cbs);
1978 }
1979 
1980 static int
1981 ssl3_get_client_kex_gost(SSL *s, CBS *cbs)
1982 {
1983 	EVP_PKEY_CTX *pkey_ctx;
1984 	EVP_PKEY *client_pub_pkey = NULL, *pk = NULL;
1985 	unsigned char premaster_secret[32];
1986 	unsigned long alg_a;
1987 	size_t outlen = 32;
1988 	CBS gostblob;
1989 	int al;
1990 	int ret = 0;
1991 
1992 	/* Get our certificate private key*/
1993 	alg_a = S3I(s)->hs.cipher->algorithm_auth;
1994 	if (alg_a & SSL_aGOST01)
1995 		pk = s->cert->pkeys[SSL_PKEY_GOST01].privatekey;
1996 
1997 	if ((pkey_ctx = EVP_PKEY_CTX_new(pk, NULL)) == NULL)
1998 		goto err;
1999 	if (EVP_PKEY_decrypt_init(pkey_ctx) <= 0)
2000 		goto gerr;
2001 
2002 	/*
2003 	 * If client certificate is present and is of the same type,
2004 	 * maybe use it for key exchange.
2005 	 * Don't mind errors from EVP_PKEY_derive_set_peer, because
2006 	 * it is completely valid to use a client certificate for
2007 	 * authorization only.
2008 	 */
2009 	if ((client_pub_pkey = X509_get_pubkey(s->session->peer)) != NULL) {
2010 		if (EVP_PKEY_derive_set_peer(pkey_ctx,
2011 		    client_pub_pkey) <= 0)
2012 			ERR_clear_error();
2013 	}
2014 
2015 	/* Decrypt session key */
2016 	if (!CBS_get_asn1(cbs, &gostblob, CBS_ASN1_SEQUENCE))
2017 		goto decode_err;
2018 	if (CBS_len(cbs) != 0)
2019 		goto decode_err;
2020 	if (EVP_PKEY_decrypt(pkey_ctx, premaster_secret, &outlen,
2021 	    CBS_data(&gostblob), CBS_len(&gostblob)) <= 0) {
2022 		SSLerror(s, SSL_R_DECRYPTION_FAILED);
2023 		goto gerr;
2024 	}
2025 
2026 	if (!tls12_derive_master_secret(s, premaster_secret, 32))
2027 		goto err;
2028 
2029 	/* Check if pubkey from client certificate was used */
2030 	if (EVP_PKEY_CTX_ctrl(pkey_ctx, -1, -1,
2031 	    EVP_PKEY_CTRL_PEER_KEY, 2, NULL) > 0)
2032 		ret = 2;
2033 	else
2034 		ret = 1;
2035  gerr:
2036 	EVP_PKEY_free(client_pub_pkey);
2037 	EVP_PKEY_CTX_free(pkey_ctx);
2038 	if (ret)
2039 		return (ret);
2040 	else
2041 		goto err;
2042 
2043  decode_err:
2044 	al = SSL_AD_DECODE_ERROR;
2045 	SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
2046 	ssl3_send_alert(s, SSL3_AL_FATAL, al);
2047  err:
2048 	return (-1);
2049 }
2050 
2051 int
2052 ssl3_get_client_key_exchange(SSL *s)
2053 {
2054 	unsigned long alg_k;
2055 	int al, ok;
2056 	CBS cbs;
2057 	long n;
2058 
2059 	/* 2048 maxlen is a guess.  How long a key does that permit? */
2060 	n = ssl3_get_message(s, SSL3_ST_SR_KEY_EXCH_A,
2061 	    SSL3_ST_SR_KEY_EXCH_B, SSL3_MT_CLIENT_KEY_EXCHANGE, 2048, &ok);
2062 	if (!ok)
2063 		return ((int)n);
2064 
2065 	if (n < 0)
2066 		goto err;
2067 
2068 	CBS_init(&cbs, s->internal->init_msg, n);
2069 
2070 	alg_k = S3I(s)->hs.cipher->algorithm_mkey;
2071 
2072 	if (alg_k & SSL_kRSA) {
2073 		if (ssl3_get_client_kex_rsa(s, &cbs) != 1)
2074 			goto err;
2075 	} else if (alg_k & SSL_kDHE) {
2076 		if (ssl3_get_client_kex_dhe(s, &cbs) != 1)
2077 			goto err;
2078 	} else if (alg_k & SSL_kECDHE) {
2079 		if (ssl3_get_client_kex_ecdhe(s, &cbs) != 1)
2080 			goto err;
2081 	} else if (alg_k & SSL_kGOST) {
2082 		if (ssl3_get_client_kex_gost(s, &cbs) != 1)
2083 			goto err;
2084 	} else {
2085 		al = SSL_AD_HANDSHAKE_FAILURE;
2086 		SSLerror(s, SSL_R_UNKNOWN_CIPHER_TYPE);
2087 		goto fatal_err;
2088 	}
2089 
2090 	if (CBS_len(&cbs) != 0) {
2091 		al = SSL_AD_DECODE_ERROR;
2092 		SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
2093 		goto fatal_err;
2094 	}
2095 
2096 	return (1);
2097 
2098  fatal_err:
2099 	ssl3_send_alert(s, SSL3_AL_FATAL, al);
2100  err:
2101 	return (-1);
2102 }
2103 
2104 int
2105 ssl3_get_cert_verify(SSL *s)
2106 {
2107 	CBS cbs, signature;
2108 	const struct ssl_sigalg *sigalg = NULL;
2109 	uint16_t sigalg_value = SIGALG_NONE;
2110 	EVP_PKEY *pkey = NULL;
2111 	X509 *peer = NULL;
2112 	EVP_MD_CTX mctx;
2113 	int al, ok, verify;
2114 	const unsigned char *hdata;
2115 	size_t hdatalen;
2116 	int type = 0;
2117 	int ret = 0;
2118 	long n;
2119 
2120 	EVP_MD_CTX_init(&mctx);
2121 
2122 	n = ssl3_get_message(s, SSL3_ST_SR_CERT_VRFY_A,
2123 	    SSL3_ST_SR_CERT_VRFY_B, -1, SSL3_RT_MAX_PLAIN_LENGTH, &ok);
2124 	if (!ok)
2125 		return ((int)n);
2126 
2127 	if (n < 0)
2128 		goto err;
2129 
2130 	CBS_init(&cbs, s->internal->init_msg, n);
2131 
2132 	if (s->session->peer != NULL) {
2133 		peer = s->session->peer;
2134 		pkey = X509_get_pubkey(peer);
2135 		type = X509_certificate_type(peer, pkey);
2136 	}
2137 
2138 	if (S3I(s)->hs.tls12.message_type != SSL3_MT_CERTIFICATE_VERIFY) {
2139 		S3I(s)->hs.tls12.reuse_message = 1;
2140 		if (peer != NULL) {
2141 			al = SSL_AD_UNEXPECTED_MESSAGE;
2142 			SSLerror(s, SSL_R_MISSING_VERIFY_MESSAGE);
2143 			goto fatal_err;
2144 		}
2145 		ret = 1;
2146 		goto end;
2147 	}
2148 
2149 	if (peer == NULL) {
2150 		SSLerror(s, SSL_R_NO_CLIENT_CERT_RECEIVED);
2151 		al = SSL_AD_UNEXPECTED_MESSAGE;
2152 		goto fatal_err;
2153 	}
2154 
2155 	if (!(type & EVP_PKT_SIGN)) {
2156 		SSLerror(s, SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE);
2157 		al = SSL_AD_ILLEGAL_PARAMETER;
2158 		goto fatal_err;
2159 	}
2160 
2161 	if (S3I(s)->change_cipher_spec) {
2162 		SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
2163 		al = SSL_AD_UNEXPECTED_MESSAGE;
2164 		goto fatal_err;
2165 	}
2166 
2167 	if (SSL_USE_SIGALGS(s)) {
2168 		if (!CBS_get_u16(&cbs, &sigalg_value))
2169 			goto decode_err;
2170 	}
2171 	if (!CBS_get_u16_length_prefixed(&cbs, &signature))
2172 		goto err;
2173 	if (CBS_len(&cbs) != 0) {
2174 		al = SSL_AD_DECODE_ERROR;
2175 		SSLerror(s, SSL_R_EXTRA_DATA_IN_MESSAGE);
2176 		goto fatal_err;
2177 	}
2178 
2179 	if (CBS_len(&signature) > EVP_PKEY_size(pkey)) {
2180 		SSLerror(s, SSL_R_WRONG_SIGNATURE_SIZE);
2181 		al = SSL_AD_DECODE_ERROR;
2182 		goto fatal_err;
2183 	}
2184 
2185 	if ((sigalg = ssl_sigalg_for_peer(s, pkey,
2186 	    sigalg_value)) == NULL) {
2187 		al = SSL_AD_DECODE_ERROR;
2188 		goto fatal_err;
2189 	}
2190 	S3I(s)->hs.peer_sigalg = sigalg;
2191 
2192 	if (SSL_USE_SIGALGS(s)) {
2193 		EVP_PKEY_CTX *pctx;
2194 
2195 		if (!tls1_transcript_data(s, &hdata, &hdatalen)) {
2196 			SSLerror(s, ERR_R_INTERNAL_ERROR);
2197 			al = SSL_AD_INTERNAL_ERROR;
2198 			goto fatal_err;
2199 		}
2200 		if (!EVP_DigestVerifyInit(&mctx, &pctx, sigalg->md(),
2201 		    NULL, pkey)) {
2202 			SSLerror(s, ERR_R_EVP_LIB);
2203 			al = SSL_AD_INTERNAL_ERROR;
2204 			goto fatal_err;
2205 		}
2206 		if ((sigalg->flags & SIGALG_FLAG_RSA_PSS) &&
2207 		    (!EVP_PKEY_CTX_set_rsa_padding(pctx,
2208 			RSA_PKCS1_PSS_PADDING) ||
2209 		    !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1))) {
2210 			al = SSL_AD_INTERNAL_ERROR;
2211 			goto fatal_err;
2212 		}
2213 		if (sigalg->key_type == EVP_PKEY_GOSTR01 &&
2214 		    EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_VERIFY,
2215 		    EVP_PKEY_CTRL_GOST_SIG_FORMAT, GOST_SIG_FORMAT_RS_LE,
2216 		    NULL) <= 0) {
2217 			al = SSL_AD_INTERNAL_ERROR;
2218 			goto fatal_err;
2219 		}
2220 		if (!EVP_DigestVerifyUpdate(&mctx, hdata, hdatalen)) {
2221 			SSLerror(s, ERR_R_EVP_LIB);
2222 			al = SSL_AD_INTERNAL_ERROR;
2223 			goto fatal_err;
2224 		}
2225 		if (EVP_DigestVerifyFinal(&mctx, CBS_data(&signature),
2226 		    CBS_len(&signature)) <= 0) {
2227 			al = SSL_AD_DECRYPT_ERROR;
2228 			SSLerror(s, SSL_R_BAD_SIGNATURE);
2229 			goto fatal_err;
2230 		}
2231 	} else if (pkey->type == EVP_PKEY_RSA) {
2232 		verify = RSA_verify(NID_md5_sha1, S3I(s)->hs.tls12.cert_verify,
2233 		    MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH, CBS_data(&signature),
2234 		    CBS_len(&signature), pkey->pkey.rsa);
2235 		if (verify < 0) {
2236 			al = SSL_AD_DECRYPT_ERROR;
2237 			SSLerror(s, SSL_R_BAD_RSA_DECRYPT);
2238 			goto fatal_err;
2239 		}
2240 		if (verify == 0) {
2241 			al = SSL_AD_DECRYPT_ERROR;
2242 			SSLerror(s, SSL_R_BAD_RSA_SIGNATURE);
2243 			goto fatal_err;
2244 		}
2245 	} else if (pkey->type == EVP_PKEY_EC) {
2246 		verify = ECDSA_verify(pkey->save_type,
2247 		    &(S3I(s)->hs.tls12.cert_verify[MD5_DIGEST_LENGTH]),
2248 		    SHA_DIGEST_LENGTH, CBS_data(&signature),
2249 		    CBS_len(&signature), pkey->pkey.ec);
2250 		if (verify <= 0) {
2251 			al = SSL_AD_DECRYPT_ERROR;
2252 			SSLerror(s, SSL_R_BAD_ECDSA_SIGNATURE);
2253 			goto fatal_err;
2254 		}
2255 #ifndef OPENSSL_NO_GOST
2256 	} else if (pkey->type == NID_id_GostR3410_94 ||
2257 	    pkey->type == NID_id_GostR3410_2001) {
2258 		unsigned char sigbuf[128];
2259 		unsigned int siglen = sizeof(sigbuf);
2260 		EVP_PKEY_CTX *pctx;
2261 		const EVP_MD *md;
2262 		int nid;
2263 
2264 		if (!tls1_transcript_data(s, &hdata, &hdatalen)) {
2265 			SSLerror(s, ERR_R_INTERNAL_ERROR);
2266 			al = SSL_AD_INTERNAL_ERROR;
2267 			goto fatal_err;
2268 		}
2269 		if (!EVP_PKEY_get_default_digest_nid(pkey, &nid) ||
2270 		    !(md = EVP_get_digestbynid(nid))) {
2271 			SSLerror(s, ERR_R_EVP_LIB);
2272 			al = SSL_AD_INTERNAL_ERROR;
2273 			goto fatal_err;
2274 		}
2275 		if ((pctx = EVP_PKEY_CTX_new(pkey, NULL)) == NULL) {
2276 			SSLerror(s, ERR_R_EVP_LIB);
2277 			al = SSL_AD_INTERNAL_ERROR;
2278 			goto fatal_err;
2279 		}
2280 		if (!EVP_DigestInit_ex(&mctx, md, NULL) ||
2281 		    !EVP_DigestUpdate(&mctx, hdata, hdatalen) ||
2282 		    !EVP_DigestFinal(&mctx, sigbuf, &siglen) ||
2283 		    (EVP_PKEY_verify_init(pctx) <= 0) ||
2284 		    (EVP_PKEY_CTX_set_signature_md(pctx, md) <= 0) ||
2285 		    (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_VERIFY,
2286 		    EVP_PKEY_CTRL_GOST_SIG_FORMAT,
2287 		    GOST_SIG_FORMAT_RS_LE, NULL) <= 0)) {
2288 			SSLerror(s, ERR_R_EVP_LIB);
2289 			al = SSL_AD_INTERNAL_ERROR;
2290 			EVP_PKEY_CTX_free(pctx);
2291 			goto fatal_err;
2292 		}
2293 		if (EVP_PKEY_verify(pctx, CBS_data(&signature),
2294 		    CBS_len(&signature), sigbuf, siglen) <= 0) {
2295 			al = SSL_AD_DECRYPT_ERROR;
2296 			SSLerror(s, SSL_R_BAD_SIGNATURE);
2297 			EVP_PKEY_CTX_free(pctx);
2298 			goto fatal_err;
2299 		}
2300 
2301 		EVP_PKEY_CTX_free(pctx);
2302 #endif
2303 	} else {
2304 		SSLerror(s, ERR_R_INTERNAL_ERROR);
2305 		al = SSL_AD_UNSUPPORTED_CERTIFICATE;
2306 		goto fatal_err;
2307 	}
2308 
2309 	ret = 1;
2310 	if (0) {
2311  decode_err:
2312 		al = SSL_AD_DECODE_ERROR;
2313 		SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
2314  fatal_err:
2315 		ssl3_send_alert(s, SSL3_AL_FATAL, al);
2316 	}
2317  end:
2318 	tls1_transcript_free(s);
2319  err:
2320 	EVP_MD_CTX_cleanup(&mctx);
2321 	EVP_PKEY_free(pkey);
2322 	return (ret);
2323 }
2324 
2325 int
2326 ssl3_get_client_certificate(SSL *s)
2327 {
2328 	CBS cbs, client_certs;
2329 	int i, ok, al, ret = -1;
2330 	X509 *x = NULL;
2331 	long n;
2332 	const unsigned char *q;
2333 	STACK_OF(X509) *sk = NULL;
2334 
2335 	n = ssl3_get_message(s, SSL3_ST_SR_CERT_A, SSL3_ST_SR_CERT_B,
2336 	    -1, s->internal->max_cert_list, &ok);
2337 	if (!ok)
2338 		return ((int)n);
2339 
2340 	if (S3I(s)->hs.tls12.message_type == SSL3_MT_CLIENT_KEY_EXCHANGE) {
2341 		if ((s->verify_mode & SSL_VERIFY_PEER) &&
2342 		    (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
2343 			SSLerror(s, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
2344 			al = SSL_AD_HANDSHAKE_FAILURE;
2345 			goto fatal_err;
2346 		}
2347 		/*
2348 		 * If tls asked for a client cert,
2349 		 * the client must return a 0 list.
2350 		 */
2351 		if (S3I(s)->hs.tls12.cert_request) {
2352 			SSLerror(s, SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST
2353 			    );
2354 			al = SSL_AD_UNEXPECTED_MESSAGE;
2355 			goto fatal_err;
2356 		}
2357 		S3I(s)->hs.tls12.reuse_message = 1;
2358 		return (1);
2359 	}
2360 
2361 	if (S3I(s)->hs.tls12.message_type != SSL3_MT_CERTIFICATE) {
2362 		al = SSL_AD_UNEXPECTED_MESSAGE;
2363 		SSLerror(s, SSL_R_WRONG_MESSAGE_TYPE);
2364 		goto fatal_err;
2365 	}
2366 
2367 	if (n < 0)
2368 		goto decode_err;
2369 
2370 	CBS_init(&cbs, s->internal->init_msg, n);
2371 
2372 	if ((sk = sk_X509_new_null()) == NULL) {
2373 		SSLerror(s, ERR_R_MALLOC_FAILURE);
2374 		goto err;
2375 	}
2376 
2377 	if (!CBS_get_u24_length_prefixed(&cbs, &client_certs) ||
2378 	    CBS_len(&cbs) != 0)
2379 		goto decode_err;
2380 
2381 	while (CBS_len(&client_certs) > 0) {
2382 		CBS cert;
2383 
2384 		if (!CBS_get_u24_length_prefixed(&client_certs, &cert)) {
2385 			al = SSL_AD_DECODE_ERROR;
2386 			SSLerror(s, SSL_R_CERT_LENGTH_MISMATCH);
2387 			goto fatal_err;
2388 		}
2389 
2390 		q = CBS_data(&cert);
2391 		x = d2i_X509(NULL, &q, CBS_len(&cert));
2392 		if (x == NULL) {
2393 			SSLerror(s, ERR_R_ASN1_LIB);
2394 			goto err;
2395 		}
2396 		if (q != CBS_data(&cert) + CBS_len(&cert)) {
2397 			al = SSL_AD_DECODE_ERROR;
2398 			SSLerror(s, SSL_R_CERT_LENGTH_MISMATCH);
2399 			goto fatal_err;
2400 		}
2401 		if (!sk_X509_push(sk, x)) {
2402 			SSLerror(s, ERR_R_MALLOC_FAILURE);
2403 			goto err;
2404 		}
2405 		x = NULL;
2406 	}
2407 
2408 	if (sk_X509_num(sk) <= 0) {
2409 		/*
2410 		 * TLS does not mind 0 certs returned.
2411 		 * Fail for TLS only if we required a certificate.
2412 		 */
2413 		if ((s->verify_mode & SSL_VERIFY_PEER) &&
2414 		    (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
2415 			SSLerror(s, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
2416 			al = SSL_AD_HANDSHAKE_FAILURE;
2417 			goto fatal_err;
2418 		}
2419 		/* No client certificate so free transcript. */
2420 		tls1_transcript_free(s);
2421 	} else {
2422 		i = ssl_verify_cert_chain(s, sk);
2423 		if (i <= 0) {
2424 			al = ssl_verify_alarm_type(s->verify_result);
2425 			SSLerror(s, SSL_R_NO_CERTIFICATE_RETURNED);
2426 			goto fatal_err;
2427 		}
2428 	}
2429 
2430 	X509_free(s->session->peer);
2431 	s->session->peer = sk_X509_shift(sk);
2432 	s->session->verify_result = s->verify_result;
2433 
2434 	/*
2435 	 * With the current implementation, sess_cert will always be NULL
2436 	 * when we arrive here
2437 	 */
2438 	if (SSI(s)->sess_cert == NULL) {
2439 		SSI(s)->sess_cert = ssl_sess_cert_new();
2440 		if (SSI(s)->sess_cert == NULL) {
2441 			SSLerror(s, ERR_R_MALLOC_FAILURE);
2442 			goto err;
2443 		}
2444 	}
2445 	sk_X509_pop_free(SSI(s)->sess_cert->cert_chain, X509_free);
2446 	SSI(s)->sess_cert->cert_chain = sk;
2447 
2448 	/*
2449 	 * Inconsistency alert: cert_chain does *not* include the
2450 	 * peer's own certificate, while we do include it in s3_clnt.c
2451 	 */
2452 
2453 	sk = NULL;
2454 
2455 	ret = 1;
2456 	if (0) {
2457  decode_err:
2458 		al = SSL_AD_DECODE_ERROR;
2459 		SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
2460  fatal_err:
2461 		ssl3_send_alert(s, SSL3_AL_FATAL, al);
2462 	}
2463  err:
2464 	X509_free(x);
2465 	sk_X509_pop_free(sk, X509_free);
2466 
2467 	return (ret);
2468 }
2469 
2470 int
2471 ssl3_send_server_certificate(SSL *s)
2472 {
2473 	CBB cbb, server_cert;
2474 	CERT_PKEY *cpk;
2475 
2476 	/*
2477 	 * Server Certificate - RFC 5246, section 7.4.2.
2478 	 */
2479 
2480 	memset(&cbb, 0, sizeof(cbb));
2481 
2482 	if (S3I(s)->hs.state == SSL3_ST_SW_CERT_A) {
2483 		if ((cpk = ssl_get_server_send_pkey(s)) == NULL) {
2484 			SSLerror(s, ERR_R_INTERNAL_ERROR);
2485 			return (0);
2486 		}
2487 
2488 		if (!ssl3_handshake_msg_start(s, &cbb, &server_cert,
2489 		    SSL3_MT_CERTIFICATE))
2490 			goto err;
2491 		if (!ssl3_output_cert_chain(s, &server_cert, cpk))
2492 			goto err;
2493 		if (!ssl3_handshake_msg_finish(s, &cbb))
2494 			goto err;
2495 
2496 		S3I(s)->hs.state = SSL3_ST_SW_CERT_B;
2497 	}
2498 
2499 	/* SSL3_ST_SW_CERT_B */
2500 	return (ssl3_handshake_write(s));
2501 
2502  err:
2503 	CBB_cleanup(&cbb);
2504 
2505 	return (0);
2506 }
2507 
2508 /* send a new session ticket (not necessarily for a new session) */
2509 int
2510 ssl3_send_newsession_ticket(SSL *s)
2511 {
2512 	CBB cbb, session_ticket, ticket;
2513 	SSL_CTX *tctx = s->initial_ctx;
2514 	size_t enc_session_len, enc_session_max_len, hmac_len;
2515 	size_t session_len = 0;
2516 	unsigned char *enc_session = NULL, *session = NULL;
2517 	unsigned char iv[EVP_MAX_IV_LENGTH];
2518 	unsigned char key_name[16];
2519 	unsigned char *hmac;
2520 	unsigned int hlen;
2521 	EVP_CIPHER_CTX ctx;
2522 	HMAC_CTX hctx;
2523 	int len;
2524 
2525 	/*
2526 	 * New Session Ticket - RFC 5077, section 3.3.
2527 	 */
2528 
2529 	EVP_CIPHER_CTX_init(&ctx);
2530 	HMAC_CTX_init(&hctx);
2531 
2532 	memset(&cbb, 0, sizeof(cbb));
2533 
2534 	if (S3I(s)->hs.state == SSL3_ST_SW_SESSION_TICKET_A) {
2535 		if (!ssl3_handshake_msg_start(s, &cbb, &session_ticket,
2536 		    SSL3_MT_NEWSESSION_TICKET))
2537 			goto err;
2538 
2539 		if (!SSL_SESSION_ticket(s->session, &session, &session_len))
2540 			goto err;
2541 		if (session_len > 0xffff)
2542 			goto err;
2543 
2544 		/*
2545 		 * Initialize HMAC and cipher contexts. If callback is present
2546 		 * it does all the work, otherwise use generated values from
2547 		 * parent context.
2548 		 */
2549 		if (tctx->internal->tlsext_ticket_key_cb != NULL) {
2550 			if (tctx->internal->tlsext_ticket_key_cb(s,
2551 			    key_name, iv, &ctx, &hctx, 1) < 0) {
2552 				EVP_CIPHER_CTX_cleanup(&ctx);
2553 				goto err;
2554 			}
2555 		} else {
2556 			arc4random_buf(iv, 16);
2557 			EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
2558 			    tctx->internal->tlsext_tick_aes_key, iv);
2559 			HMAC_Init_ex(&hctx, tctx->internal->tlsext_tick_hmac_key,
2560 			    16, EVP_sha256(), NULL);
2561 			memcpy(key_name, tctx->internal->tlsext_tick_key_name, 16);
2562 		}
2563 
2564 		/* Encrypt the session state. */
2565 		enc_session_max_len = session_len + EVP_MAX_BLOCK_LENGTH;
2566 		if ((enc_session = calloc(1, enc_session_max_len)) == NULL)
2567 			goto err;
2568 		enc_session_len = 0;
2569 		if (!EVP_EncryptUpdate(&ctx, enc_session, &len, session,
2570 		    session_len))
2571 			goto err;
2572 		enc_session_len += len;
2573 		if (!EVP_EncryptFinal_ex(&ctx, enc_session + enc_session_len,
2574 		    &len))
2575 			goto err;
2576 		enc_session_len += len;
2577 
2578 		if (enc_session_len > enc_session_max_len)
2579 			goto err;
2580 
2581 		/* Generate the HMAC. */
2582 		if (!HMAC_Update(&hctx, key_name, sizeof(key_name)))
2583 			goto err;
2584 		if (!HMAC_Update(&hctx, iv, EVP_CIPHER_CTX_iv_length(&ctx)))
2585 			goto err;
2586 		if (!HMAC_Update(&hctx, enc_session, enc_session_len))
2587 			goto err;
2588 
2589 		if ((hmac_len = HMAC_size(&hctx)) <= 0)
2590 			goto err;
2591 
2592 		/*
2593 		 * Ticket lifetime hint (advisory only):
2594 		 * We leave this unspecified for resumed session
2595 		 * (for simplicity), and guess that tickets for new
2596 		 * sessions will live as long as their sessions.
2597 		 */
2598 		if (!CBB_add_u32(&session_ticket,
2599 		    s->internal->hit ? 0 : s->session->timeout))
2600 			goto err;
2601 
2602 		if (!CBB_add_u16_length_prefixed(&session_ticket, &ticket))
2603 			goto err;
2604 		if (!CBB_add_bytes(&ticket, key_name, sizeof(key_name)))
2605 			goto err;
2606 		if (!CBB_add_bytes(&ticket, iv, EVP_CIPHER_CTX_iv_length(&ctx)))
2607 			goto err;
2608 		if (!CBB_add_bytes(&ticket, enc_session, enc_session_len))
2609 			goto err;
2610 		if (!CBB_add_space(&ticket, &hmac, hmac_len))
2611 			goto err;
2612 
2613 		if (!HMAC_Final(&hctx, hmac, &hlen))
2614 			goto err;
2615 		if (hlen != hmac_len)
2616 			goto err;
2617 
2618 		if (!ssl3_handshake_msg_finish(s, &cbb))
2619 			goto err;
2620 
2621 		S3I(s)->hs.state = SSL3_ST_SW_SESSION_TICKET_B;
2622 	}
2623 
2624 	EVP_CIPHER_CTX_cleanup(&ctx);
2625 	HMAC_CTX_cleanup(&hctx);
2626 	freezero(session, session_len);
2627 	free(enc_session);
2628 
2629 	/* SSL3_ST_SW_SESSION_TICKET_B */
2630 	return (ssl3_handshake_write(s));
2631 
2632  err:
2633 	CBB_cleanup(&cbb);
2634 	EVP_CIPHER_CTX_cleanup(&ctx);
2635 	HMAC_CTX_cleanup(&hctx);
2636 	freezero(session, session_len);
2637 	free(enc_session);
2638 
2639 	return (-1);
2640 }
2641 
2642 int
2643 ssl3_send_cert_status(SSL *s)
2644 {
2645 	CBB cbb, certstatus, ocspresp;
2646 
2647 	memset(&cbb, 0, sizeof(cbb));
2648 
2649 	if (S3I(s)->hs.state == SSL3_ST_SW_CERT_STATUS_A) {
2650 		if (!ssl3_handshake_msg_start(s, &cbb, &certstatus,
2651 		    SSL3_MT_CERTIFICATE_STATUS))
2652 			goto err;
2653 		if (!CBB_add_u8(&certstatus, s->tlsext_status_type))
2654 			goto err;
2655 		if (!CBB_add_u24_length_prefixed(&certstatus, &ocspresp))
2656 			goto err;
2657 		if (!CBB_add_bytes(&ocspresp, s->internal->tlsext_ocsp_resp,
2658 		    s->internal->tlsext_ocsp_resp_len))
2659 			goto err;
2660 		if (!ssl3_handshake_msg_finish(s, &cbb))
2661 			goto err;
2662 
2663 		S3I(s)->hs.state = SSL3_ST_SW_CERT_STATUS_B;
2664 	}
2665 
2666 	/* SSL3_ST_SW_CERT_STATUS_B */
2667 	return (ssl3_handshake_write(s));
2668 
2669  err:
2670 	CBB_cleanup(&cbb);
2671 
2672 	return (-1);
2673 }
2674