1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.]
56 */
57 /* ====================================================================
58 * Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
59 *
60 * Redistribution and use in source and binary forms, with or without
61 * modification, are permitted provided that the following conditions
62 * are met:
63 *
64 * 1. Redistributions of source code must retain the above copyright
65 * notice, this list of conditions and the following disclaimer.
66 *
67 * 2. Redistributions in binary form must reproduce the above copyright
68 * notice, this list of conditions and the following disclaimer in
69 * the documentation and/or other materials provided with the
70 * distribution.
71 *
72 * 3. All advertising materials mentioning features or use of this
73 * software must display the following acknowledgment:
74 * "This product includes software developed by the OpenSSL Project
75 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
76 *
77 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
78 * endorse or promote products derived from this software without
79 * prior written permission. For written permission, please contact
80 * openssl-core@openssl.org.
81 *
82 * 5. Products derived from this software may not be called "OpenSSL"
83 * nor may "OpenSSL" appear in their names without prior written
84 * permission of the OpenSSL Project.
85 *
86 * 6. Redistributions of any form whatsoever must retain the following
87 * acknowledgment:
88 * "This product includes software developed by the OpenSSL Project
89 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
90 *
91 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
92 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
93 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
94 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
95 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
96 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
97 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
98 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
99 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
100 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
101 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
102 * OF THE POSSIBILITY OF SUCH DAMAGE.
103 * ====================================================================
104 *
105 * This product includes cryptographic software written by Eric Young
106 * (eay@cryptsoft.com). This product includes software written by Tim
107 * Hudson (tjh@cryptsoft.com).
108 *
109 */
110 /* ====================================================================
111 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
112 *
113 * Portions of the attached software ("Contribution") are developed by
114 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
115 *
116 * The Contribution is licensed pursuant to the OpenSSL open source
117 * license provided above.
118 *
119 * ECC cipher suite support in OpenSSL originally written by
120 * Vipul Gupta and Sumit Gupta of Sun Microsystems Laboratories.
121 *
122 */
123 /* ====================================================================
124 * Copyright 2005 Nokia. All rights reserved.
125 *
126 * The portions of the attached software ("Contribution") is developed by
127 * Nokia Corporation and is licensed pursuant to the OpenSSL open source
128 * license.
129 *
130 * The Contribution, originally written by Mika Kousa and Pasi Eronen of
131 * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
132 * support (see RFC 4279) to OpenSSL.
133 *
134 * No patent licenses or other rights except those expressly stated in
135 * the OpenSSL open source license shall be deemed granted or received
136 * expressly, by implication, estoppel, or otherwise.
137 *
138 * No assurances are provided by Nokia that the Contribution does not
139 * infringe the patent or other intellectual property rights of any third
140 * party or that the license provides you with all the necessary rights
141 * to make use of the Contribution.
142 *
143 * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
144 * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
145 * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
146 * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
147 * OTHERWISE. */
148
149 #include <openssl/ssl.h>
150
151 #include <assert.h>
152 #include <stdio.h>
153 #include <string.h>
154
155 #include <openssl/bn.h>
156 #include <openssl/buf.h>
157 #include <openssl/bytestring.h>
158 #include <openssl/cipher.h>
159 #include <openssl/dh.h>
160 #include <openssl/ec.h>
161 #include <openssl/ecdsa.h>
162 #include <openssl/err.h>
163 #include <openssl/evp.h>
164 #include <openssl/hmac.h>
165 #include <openssl/md5.h>
166 #include <openssl/mem.h>
167 #include <openssl/obj.h>
168 #include <openssl/rand.h>
169 #include <openssl/sha.h>
170 #include <openssl/x509.h>
171
172 #include "internal.h"
173 #include "../crypto/internal.h"
174 #include "../crypto/dh/internal.h"
175
176
ssl3_accept(SSL * ssl)177 int ssl3_accept(SSL *ssl) {
178 BUF_MEM *buf = NULL;
179 uint32_t alg_a;
180 void (*cb)(const SSL *ssl, int type, int value) = NULL;
181 int ret = -1;
182 int new_state, state, skip = 0;
183
184 assert(ssl->handshake_func == ssl3_accept);
185 assert(ssl->server);
186 assert(!SSL_IS_DTLS(ssl));
187
188 ERR_clear_error();
189 ERR_clear_system_error();
190
191 if (ssl->info_callback != NULL) {
192 cb = ssl->info_callback;
193 } else if (ssl->ctx->info_callback != NULL) {
194 cb = ssl->ctx->info_callback;
195 }
196
197 ssl->in_handshake++;
198
199 if (ssl->cert == NULL) {
200 OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATE_SET);
201 return -1;
202 }
203
204 for (;;) {
205 state = ssl->state;
206
207 switch (ssl->state) {
208 case SSL_ST_ACCEPT:
209 if (cb != NULL) {
210 cb(ssl, SSL_CB_HANDSHAKE_START, 1);
211 }
212
213 if (ssl->init_buf == NULL) {
214 buf = BUF_MEM_new();
215 if (!buf || !BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
216 ret = -1;
217 goto end;
218 }
219 ssl->init_buf = buf;
220 buf = NULL;
221 }
222 ssl->init_num = 0;
223
224 /* Enable a write buffer. This groups handshake messages within a flight
225 * into a single write. */
226 if (!ssl_init_wbio_buffer(ssl, 1)) {
227 ret = -1;
228 goto end;
229 }
230
231 if (!ssl3_init_handshake_buffer(ssl)) {
232 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
233 ret = -1;
234 goto end;
235 }
236
237 if (!ssl->s3->have_version) {
238 ssl->state = SSL3_ST_SR_INITIAL_BYTES;
239 } else {
240 ssl->state = SSL3_ST_SR_CLNT_HELLO_A;
241 }
242 break;
243
244 case SSL3_ST_SR_INITIAL_BYTES:
245 ret = ssl3_get_initial_bytes(ssl);
246 if (ret <= 0) {
247 goto end;
248 }
249 /* ssl3_get_initial_bytes sets ssl->state to one of
250 * SSL3_ST_SR_V2_CLIENT_HELLO or SSL3_ST_SR_CLNT_HELLO_A on success. */
251 break;
252
253 case SSL3_ST_SR_V2_CLIENT_HELLO:
254 ret = ssl3_get_v2_client_hello(ssl);
255 if (ret <= 0) {
256 goto end;
257 }
258 ssl->state = SSL3_ST_SR_CLNT_HELLO_A;
259 break;
260
261 case SSL3_ST_SR_CLNT_HELLO_A:
262 case SSL3_ST_SR_CLNT_HELLO_B:
263 case SSL3_ST_SR_CLNT_HELLO_C:
264 case SSL3_ST_SR_CLNT_HELLO_D:
265 ssl->shutdown = 0;
266 ret = ssl3_get_client_hello(ssl);
267 if (ret <= 0) {
268 goto end;
269 }
270 ssl->state = SSL3_ST_SW_SRVR_HELLO_A;
271 ssl->init_num = 0;
272 break;
273
274 case SSL3_ST_SW_SRVR_HELLO_A:
275 case SSL3_ST_SW_SRVR_HELLO_B:
276 ret = ssl3_send_server_hello(ssl);
277 if (ret <= 0) {
278 goto end;
279 }
280 if (ssl->hit) {
281 if (ssl->tlsext_ticket_expected) {
282 ssl->state = SSL3_ST_SW_SESSION_TICKET_A;
283 } else {
284 ssl->state = SSL3_ST_SW_CHANGE_A;
285 }
286 } else {
287 ssl->state = SSL3_ST_SW_CERT_A;
288 }
289 ssl->init_num = 0;
290 break;
291
292 case SSL3_ST_SW_CERT_A:
293 case SSL3_ST_SW_CERT_B:
294 if (ssl_cipher_has_server_public_key(ssl->s3->tmp.new_cipher)) {
295 ret = ssl3_send_server_certificate(ssl);
296 if (ret <= 0) {
297 goto end;
298 }
299 if (ssl->s3->tmp.certificate_status_expected) {
300 ssl->state = SSL3_ST_SW_CERT_STATUS_A;
301 } else {
302 ssl->state = SSL3_ST_SW_KEY_EXCH_A;
303 }
304 } else {
305 skip = 1;
306 ssl->state = SSL3_ST_SW_KEY_EXCH_A;
307 }
308 ssl->init_num = 0;
309 break;
310
311 case SSL3_ST_SW_CERT_STATUS_A:
312 case SSL3_ST_SW_CERT_STATUS_B:
313 ret = ssl3_send_certificate_status(ssl);
314 if (ret <= 0) {
315 goto end;
316 }
317 ssl->state = SSL3_ST_SW_KEY_EXCH_A;
318 ssl->init_num = 0;
319 break;
320
321 case SSL3_ST_SW_KEY_EXCH_A:
322 case SSL3_ST_SW_KEY_EXCH_B:
323 case SSL3_ST_SW_KEY_EXCH_C:
324 alg_a = ssl->s3->tmp.new_cipher->algorithm_auth;
325
326 /* Send a ServerKeyExchange message if:
327 * - The key exchange is ephemeral or anonymous
328 * Diffie-Hellman.
329 * - There is a PSK identity hint.
330 *
331 * TODO(davidben): This logic is currently duplicated in d1_srvr.c. Fix
332 * this. In the meantime, keep them in sync. */
333 if (ssl_cipher_requires_server_key_exchange(ssl->s3->tmp.new_cipher) ||
334 ((alg_a & SSL_aPSK) && ssl->psk_identity_hint)) {
335 ret = ssl3_send_server_key_exchange(ssl);
336 if (ret <= 0) {
337 goto end;
338 }
339 } else {
340 skip = 1;
341 }
342
343 ssl->state = SSL3_ST_SW_CERT_REQ_A;
344 ssl->init_num = 0;
345 break;
346
347 case SSL3_ST_SW_CERT_REQ_A:
348 case SSL3_ST_SW_CERT_REQ_B:
349 if (ssl->s3->tmp.cert_request) {
350 ret = ssl3_send_certificate_request(ssl);
351 if (ret <= 0) {
352 goto end;
353 }
354 } else {
355 skip = 1;
356 }
357 ssl->state = SSL3_ST_SW_SRVR_DONE_A;
358 ssl->init_num = 0;
359 break;
360
361 case SSL3_ST_SW_SRVR_DONE_A:
362 case SSL3_ST_SW_SRVR_DONE_B:
363 ret = ssl3_send_server_done(ssl);
364 if (ret <= 0) {
365 goto end;
366 }
367 ssl->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
368 ssl->state = SSL3_ST_SW_FLUSH;
369 ssl->init_num = 0;
370 break;
371
372 case SSL3_ST_SW_FLUSH:
373 /* This code originally checked to see if any data was pending using
374 * BIO_CTRL_INFO and then flushed. This caused problems as documented
375 * in PR#1939. The proposed fix doesn't completely resolve this issue
376 * as buggy implementations of BIO_CTRL_PENDING still exist. So instead
377 * we just flush unconditionally. */
378 ssl->rwstate = SSL_WRITING;
379 if (BIO_flush(ssl->wbio) <= 0) {
380 ret = -1;
381 goto end;
382 }
383 ssl->rwstate = SSL_NOTHING;
384
385 ssl->state = ssl->s3->tmp.next_state;
386 break;
387
388 case SSL3_ST_SR_CERT_A:
389 case SSL3_ST_SR_CERT_B:
390 if (ssl->s3->tmp.cert_request) {
391 ret = ssl3_get_client_certificate(ssl);
392 if (ret <= 0) {
393 goto end;
394 }
395 }
396 ssl->init_num = 0;
397 ssl->state = SSL3_ST_SR_KEY_EXCH_A;
398 break;
399
400 case SSL3_ST_SR_KEY_EXCH_A:
401 case SSL3_ST_SR_KEY_EXCH_B:
402 case SSL3_ST_SR_KEY_EXCH_C:
403 ret = ssl3_get_client_key_exchange(ssl);
404 if (ret <= 0) {
405 goto end;
406 }
407 ssl->state = SSL3_ST_SR_CERT_VRFY_A;
408 ssl->init_num = 0;
409 break;
410
411 case SSL3_ST_SR_CERT_VRFY_A:
412 case SSL3_ST_SR_CERT_VRFY_B:
413 ret = ssl3_get_cert_verify(ssl);
414 if (ret <= 0) {
415 goto end;
416 }
417
418 ssl->state = SSL3_ST_SR_CHANGE;
419 ssl->init_num = 0;
420 break;
421
422 case SSL3_ST_SR_CHANGE:
423 ret = ssl->method->ssl_read_change_cipher_spec(ssl);
424 if (ret <= 0) {
425 goto end;
426 }
427
428 if (!ssl3_do_change_cipher_spec(ssl)) {
429 ret = -1;
430 goto end;
431 }
432
433 if (ssl->s3->next_proto_neg_seen) {
434 ssl->state = SSL3_ST_SR_NEXT_PROTO_A;
435 } else if (ssl->s3->tlsext_channel_id_valid) {
436 ssl->state = SSL3_ST_SR_CHANNEL_ID_A;
437 } else {
438 ssl->state = SSL3_ST_SR_FINISHED_A;
439 }
440 break;
441
442 case SSL3_ST_SR_NEXT_PROTO_A:
443 case SSL3_ST_SR_NEXT_PROTO_B:
444 ret = ssl3_get_next_proto(ssl);
445 if (ret <= 0) {
446 goto end;
447 }
448 ssl->init_num = 0;
449 if (ssl->s3->tlsext_channel_id_valid) {
450 ssl->state = SSL3_ST_SR_CHANNEL_ID_A;
451 } else {
452 ssl->state = SSL3_ST_SR_FINISHED_A;
453 }
454 break;
455
456 case SSL3_ST_SR_CHANNEL_ID_A:
457 case SSL3_ST_SR_CHANNEL_ID_B:
458 ret = ssl3_get_channel_id(ssl);
459 if (ret <= 0) {
460 goto end;
461 }
462 ssl->init_num = 0;
463 ssl->state = SSL3_ST_SR_FINISHED_A;
464 break;
465
466 case SSL3_ST_SR_FINISHED_A:
467 case SSL3_ST_SR_FINISHED_B:
468 ret = ssl3_get_finished(ssl, SSL3_ST_SR_FINISHED_A,
469 SSL3_ST_SR_FINISHED_B);
470 if (ret <= 0) {
471 goto end;
472 }
473
474 if (ssl->hit) {
475 ssl->state = SSL_ST_OK;
476 } else if (ssl->tlsext_ticket_expected) {
477 ssl->state = SSL3_ST_SW_SESSION_TICKET_A;
478 } else {
479 ssl->state = SSL3_ST_SW_CHANGE_A;
480 }
481 /* If this is a full handshake with ChannelID then record the hashshake
482 * hashes in |ssl->session| in case we need them to verify a ChannelID
483 * signature on a resumption of this session in the future. */
484 if (!ssl->hit && ssl->s3->tlsext_channel_id_valid) {
485 ret = tls1_record_handshake_hashes_for_channel_id(ssl);
486 if (ret <= 0) {
487 goto end;
488 }
489 }
490 ssl->init_num = 0;
491 break;
492
493 case SSL3_ST_SW_SESSION_TICKET_A:
494 case SSL3_ST_SW_SESSION_TICKET_B:
495 ret = ssl3_send_new_session_ticket(ssl);
496 if (ret <= 0) {
497 goto end;
498 }
499 ssl->state = SSL3_ST_SW_CHANGE_A;
500 ssl->init_num = 0;
501 break;
502
503 case SSL3_ST_SW_CHANGE_A:
504 case SSL3_ST_SW_CHANGE_B:
505 ssl->session->cipher = ssl->s3->tmp.new_cipher;
506 if (!ssl->enc_method->setup_key_block(ssl)) {
507 ret = -1;
508 goto end;
509 }
510
511 ret = ssl3_send_change_cipher_spec(ssl, SSL3_ST_SW_CHANGE_A,
512 SSL3_ST_SW_CHANGE_B);
513 if (ret <= 0) {
514 goto end;
515 }
516 ssl->state = SSL3_ST_SW_FINISHED_A;
517 ssl->init_num = 0;
518
519 if (!ssl->enc_method->change_cipher_state(
520 ssl, SSL3_CHANGE_CIPHER_SERVER_WRITE)) {
521 ret = -1;
522 goto end;
523 }
524 break;
525
526 case SSL3_ST_SW_FINISHED_A:
527 case SSL3_ST_SW_FINISHED_B:
528 ret = ssl3_send_finished(ssl, SSL3_ST_SW_FINISHED_A,
529 SSL3_ST_SW_FINISHED_B,
530 ssl->enc_method->server_finished_label,
531 ssl->enc_method->server_finished_label_len);
532 if (ret <= 0) {
533 goto end;
534 }
535 ssl->state = SSL3_ST_SW_FLUSH;
536 if (ssl->hit) {
537 ssl->s3->tmp.next_state = SSL3_ST_SR_CHANGE;
538 } else {
539 ssl->s3->tmp.next_state = SSL_ST_OK;
540 }
541 ssl->init_num = 0;
542 break;
543
544 case SSL_ST_OK:
545 /* clean a few things up */
546 ssl3_cleanup_key_block(ssl);
547
548 BUF_MEM_free(ssl->init_buf);
549 ssl->init_buf = NULL;
550
551 /* remove buffering on output */
552 ssl_free_wbio_buffer(ssl);
553
554 ssl->init_num = 0;
555
556 /* If we aren't retaining peer certificates then we can discard it
557 * now. */
558 if (ssl->ctx->retain_only_sha256_of_client_certs) {
559 X509_free(ssl->session->peer);
560 ssl->session->peer = NULL;
561 sk_X509_pop_free(ssl->session->cert_chain, X509_free);
562 ssl->session->cert_chain = NULL;
563 }
564
565 ssl->s3->initial_handshake_complete = 1;
566
567 ssl_update_cache(ssl, SSL_SESS_CACHE_SERVER);
568
569 if (cb != NULL) {
570 cb(ssl, SSL_CB_HANDSHAKE_DONE, 1);
571 }
572
573 ret = 1;
574 goto end;
575
576 default:
577 OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_STATE);
578 ret = -1;
579 goto end;
580 }
581
582 if (!ssl->s3->tmp.reuse_message && !skip && cb != NULL &&
583 ssl->state != state) {
584 new_state = ssl->state;
585 ssl->state = state;
586 cb(ssl, SSL_CB_ACCEPT_LOOP, 1);
587 ssl->state = new_state;
588 }
589 skip = 0;
590 }
591
592 end:
593 ssl->in_handshake--;
594 BUF_MEM_free(buf);
595 if (cb != NULL) {
596 cb(ssl, SSL_CB_ACCEPT_EXIT, ret);
597 }
598 return ret;
599 }
600
ssl3_get_initial_bytes(SSL * ssl)601 int ssl3_get_initial_bytes(SSL *ssl) {
602 /* Read the first 5 bytes, the size of the TLS record header. This is
603 * sufficient to detect a V2ClientHello and ensures that we never read beyond
604 * the first record. */
605 int ret = ssl_read_buffer_extend_to(ssl, SSL3_RT_HEADER_LENGTH);
606 if (ret <= 0) {
607 return ret;
608 }
609 assert(ssl_read_buffer_len(ssl) == SSL3_RT_HEADER_LENGTH);
610 const uint8_t *p = ssl_read_buffer(ssl);
611
612 /* Some dedicated error codes for protocol mixups should the application wish
613 * to interpret them differently. (These do not overlap with ClientHello or
614 * V2ClientHello.) */
615 if (strncmp("GET ", (const char *)p, 4) == 0 ||
616 strncmp("POST ", (const char *)p, 5) == 0 ||
617 strncmp("HEAD ", (const char *)p, 5) == 0 ||
618 strncmp("PUT ", (const char *)p, 4) == 0) {
619 OPENSSL_PUT_ERROR(SSL, SSL_R_HTTP_REQUEST);
620 return -1;
621 }
622 if (strncmp("CONNE", (const char *)p, 5) == 0) {
623 OPENSSL_PUT_ERROR(SSL, SSL_R_HTTPS_PROXY_REQUEST);
624 return -1;
625 }
626
627 /* Determine if this is a V2ClientHello. */
628 if ((p[0] & 0x80) && p[2] == SSL2_MT_CLIENT_HELLO &&
629 p[3] >= SSL3_VERSION_MAJOR) {
630 /* This is a V2ClientHello. */
631 ssl->state = SSL3_ST_SR_V2_CLIENT_HELLO;
632 return 1;
633 }
634
635 /* Fall through to the standard logic. */
636 ssl->state = SSL3_ST_SR_CLNT_HELLO_A;
637 return 1;
638 }
639
ssl3_get_v2_client_hello(SSL * ssl)640 int ssl3_get_v2_client_hello(SSL *ssl) {
641 const uint8_t *p;
642 int ret;
643 CBS v2_client_hello, cipher_specs, session_id, challenge;
644 size_t msg_length, rand_len, len;
645 uint8_t msg_type;
646 uint16_t version, cipher_spec_length, session_id_length, challenge_length;
647 CBB client_hello, hello_body, cipher_suites;
648 uint8_t random[SSL3_RANDOM_SIZE];
649
650 /* Determine the length of the V2ClientHello. */
651 assert(ssl_read_buffer_len(ssl) >= SSL3_RT_HEADER_LENGTH);
652 p = ssl_read_buffer(ssl);
653 msg_length = ((p[0] & 0x7f) << 8) | p[1];
654 if (msg_length > (1024 * 4)) {
655 OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE);
656 return -1;
657 }
658 if (msg_length < SSL3_RT_HEADER_LENGTH - 2) {
659 /* Reject lengths that are too short early. We have already read
660 * |SSL3_RT_HEADER_LENGTH| bytes, so we should not attempt to process an
661 * (invalid) V2ClientHello which would be shorter than that. */
662 OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_LENGTH_MISMATCH);
663 return -1;
664 }
665
666 /* Read the remainder of the V2ClientHello. */
667 ret = ssl_read_buffer_extend_to(ssl, 2 + msg_length);
668 if (ret <= 0) {
669 return ret;
670 }
671 assert(ssl_read_buffer_len(ssl) == msg_length + 2);
672 CBS_init(&v2_client_hello, ssl_read_buffer(ssl) + 2, msg_length);
673
674 /* The V2ClientHello without the length is incorporated into the handshake
675 * hash. */
676 if (!ssl3_update_handshake_hash(ssl, CBS_data(&v2_client_hello),
677 CBS_len(&v2_client_hello))) {
678 return -1;
679 }
680 if (ssl->msg_callback) {
681 ssl->msg_callback(0, SSL2_VERSION, 0, CBS_data(&v2_client_hello),
682 CBS_len(&v2_client_hello), ssl, ssl->msg_callback_arg);
683 }
684
685 if (!CBS_get_u8(&v2_client_hello, &msg_type) ||
686 !CBS_get_u16(&v2_client_hello, &version) ||
687 !CBS_get_u16(&v2_client_hello, &cipher_spec_length) ||
688 !CBS_get_u16(&v2_client_hello, &session_id_length) ||
689 !CBS_get_u16(&v2_client_hello, &challenge_length) ||
690 !CBS_get_bytes(&v2_client_hello, &cipher_specs, cipher_spec_length) ||
691 !CBS_get_bytes(&v2_client_hello, &session_id, session_id_length) ||
692 !CBS_get_bytes(&v2_client_hello, &challenge, challenge_length) ||
693 CBS_len(&v2_client_hello) != 0) {
694 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
695 return -1;
696 }
697
698 /* msg_type has already been checked. */
699 assert(msg_type == SSL2_MT_CLIENT_HELLO);
700
701 /* The client_random is the V2ClientHello challenge. Truncate or
702 * left-pad with zeros as needed. */
703 memset(random, 0, SSL3_RANDOM_SIZE);
704 rand_len = CBS_len(&challenge);
705 if (rand_len > SSL3_RANDOM_SIZE) {
706 rand_len = SSL3_RANDOM_SIZE;
707 }
708 memcpy(random + (SSL3_RANDOM_SIZE - rand_len), CBS_data(&challenge),
709 rand_len);
710
711 /* Write out an equivalent SSLv3 ClientHello. */
712 CBB_zero(&client_hello);
713 if (!CBB_init_fixed(&client_hello, (uint8_t *)ssl->init_buf->data,
714 ssl->init_buf->max) ||
715 !CBB_add_u8(&client_hello, SSL3_MT_CLIENT_HELLO) ||
716 !CBB_add_u24_length_prefixed(&client_hello, &hello_body) ||
717 !CBB_add_u16(&hello_body, version) ||
718 !CBB_add_bytes(&hello_body, random, SSL3_RANDOM_SIZE) ||
719 /* No session id. */
720 !CBB_add_u8(&hello_body, 0) ||
721 !CBB_add_u16_length_prefixed(&hello_body, &cipher_suites)) {
722 CBB_cleanup(&client_hello);
723 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
724 return -1;
725 }
726
727 /* Copy the cipher suites. */
728 while (CBS_len(&cipher_specs) > 0) {
729 uint32_t cipher_spec;
730 if (!CBS_get_u24(&cipher_specs, &cipher_spec)) {
731 CBB_cleanup(&client_hello);
732 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
733 return -1;
734 }
735
736 /* Skip SSLv2 ciphers. */
737 if ((cipher_spec & 0xff0000) != 0) {
738 continue;
739 }
740 if (!CBB_add_u16(&cipher_suites, cipher_spec)) {
741 CBB_cleanup(&client_hello);
742 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
743 return -1;
744 }
745 }
746
747 /* Add the null compression scheme and finish. */
748 if (!CBB_add_u8(&hello_body, 1) || !CBB_add_u8(&hello_body, 0) ||
749 !CBB_finish(&client_hello, NULL, &len)) {
750 CBB_cleanup(&client_hello);
751 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
752 return -1;
753 }
754
755 /* Mark the message for "re"-use by the version-specific method. */
756 ssl->s3->tmp.reuse_message = 1;
757 ssl->s3->tmp.message_type = SSL3_MT_CLIENT_HELLO;
758 /* The handshake message header is 4 bytes. */
759 ssl->s3->tmp.message_size = len - 4;
760
761 /* Consume and discard the V2ClientHello. */
762 ssl_read_buffer_consume(ssl, 2 + msg_length);
763 ssl_read_buffer_discard(ssl);
764
765 return 1;
766 }
767
ssl3_get_client_hello(SSL * ssl)768 int ssl3_get_client_hello(SSL *ssl) {
769 int ok, al = SSL_AD_INTERNAL_ERROR, ret = -1;
770 long n;
771 const SSL_CIPHER *c;
772 STACK_OF(SSL_CIPHER) *ciphers = NULL;
773 struct ssl_early_callback_ctx early_ctx;
774 CBS client_hello;
775 uint16_t client_version;
776 CBS client_random, session_id, cipher_suites, compression_methods;
777 SSL_SESSION *session = NULL;
778
779 /* We do this so that we will respond with our native type. If we are TLSv1
780 * and we get SSLv3, we will respond with TLSv1, This down switching should
781 * be handled by a different method. If we are SSLv3, we will respond with
782 * SSLv3, even if prompted with TLSv1. */
783 switch (ssl->state) {
784 case SSL3_ST_SR_CLNT_HELLO_A:
785 case SSL3_ST_SR_CLNT_HELLO_B:
786 n = ssl->method->ssl_get_message(
787 ssl, SSL3_ST_SR_CLNT_HELLO_A, SSL3_ST_SR_CLNT_HELLO_B,
788 SSL3_MT_CLIENT_HELLO, SSL3_RT_MAX_PLAIN_LENGTH,
789 ssl_hash_message, &ok);
790
791 if (!ok) {
792 return n;
793 }
794
795 ssl->state = SSL3_ST_SR_CLNT_HELLO_C;
796 /* fallthrough */
797 case SSL3_ST_SR_CLNT_HELLO_C:
798 case SSL3_ST_SR_CLNT_HELLO_D:
799 /* We have previously parsed the ClientHello message, and can't call
800 * ssl_get_message again without hashing the message into the Finished
801 * digest again. */
802 n = ssl->init_num;
803
804 memset(&early_ctx, 0, sizeof(early_ctx));
805 early_ctx.ssl = ssl;
806 early_ctx.client_hello = ssl->init_msg;
807 early_ctx.client_hello_len = n;
808 if (!ssl_early_callback_init(&early_ctx)) {
809 al = SSL_AD_DECODE_ERROR;
810 OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_PARSE_FAILED);
811 goto f_err;
812 }
813
814 if (ssl->state == SSL3_ST_SR_CLNT_HELLO_C &&
815 ssl->ctx->select_certificate_cb != NULL) {
816 ssl->state = SSL3_ST_SR_CLNT_HELLO_D;
817 switch (ssl->ctx->select_certificate_cb(&early_ctx)) {
818 case 0:
819 ssl->rwstate = SSL_CERTIFICATE_SELECTION_PENDING;
820 goto err;
821
822 case -1:
823 /* Connection rejected. */
824 al = SSL_AD_ACCESS_DENIED;
825 OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
826 goto f_err;
827
828 default:
829 /* fallthrough */;
830 }
831 }
832 ssl->state = SSL3_ST_SR_CLNT_HELLO_D;
833 break;
834
835 default:
836 OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_STATE);
837 return -1;
838 }
839
840 CBS_init(&client_hello, ssl->init_msg, n);
841 if (!CBS_get_u16(&client_hello, &client_version) ||
842 !CBS_get_bytes(&client_hello, &client_random, SSL3_RANDOM_SIZE) ||
843 !CBS_get_u8_length_prefixed(&client_hello, &session_id) ||
844 CBS_len(&session_id) > SSL_MAX_SSL_SESSION_ID_LENGTH) {
845 al = SSL_AD_DECODE_ERROR;
846 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
847 goto f_err;
848 }
849
850 /* use version from inside client hello, not from record header (may differ:
851 * see RFC 2246, Appendix E, second paragraph) */
852 ssl->client_version = client_version;
853
854 /* Load the client random. */
855 memcpy(ssl->s3->client_random, CBS_data(&client_random), SSL3_RANDOM_SIZE);
856
857 if (SSL_IS_DTLS(ssl)) {
858 CBS cookie;
859
860 if (!CBS_get_u8_length_prefixed(&client_hello, &cookie) ||
861 CBS_len(&cookie) > DTLS1_COOKIE_LENGTH) {
862 al = SSL_AD_DECODE_ERROR;
863 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
864 goto f_err;
865 }
866 }
867
868 /* Note: This codepath may run twice if |ssl_get_prev_session| completes
869 * asynchronously.
870 *
871 * TODO(davidben): Clean up the order of events around ClientHello
872 * processing. */
873 if (!ssl->s3->have_version) {
874 /* Select version to use */
875 uint16_t version = ssl3_get_mutual_version(ssl, client_version);
876 if (version == 0) {
877 OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_PROTOCOL);
878 ssl->version = ssl->client_version;
879 al = SSL_AD_PROTOCOL_VERSION;
880 goto f_err;
881 }
882 ssl->version = version;
883 ssl->enc_method = ssl3_get_enc_method(version);
884 assert(ssl->enc_method != NULL);
885 /* At this point, the connection's version is known and |ssl->version| is
886 * fixed. Begin enforcing the record-layer version. */
887 ssl->s3->have_version = 1;
888 } else if (SSL_IS_DTLS(ssl) ? (ssl->client_version > ssl->version)
889 : (ssl->client_version < ssl->version)) {
890 OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_NUMBER);
891 al = SSL_AD_PROTOCOL_VERSION;
892 goto f_err;
893 }
894
895 ssl->hit = 0;
896 int send_new_ticket = 0;
897 switch (ssl_get_prev_session(ssl, &session, &send_new_ticket, &early_ctx)) {
898 case ssl_session_success:
899 break;
900 case ssl_session_error:
901 goto err;
902 case ssl_session_retry:
903 ssl->rwstate = SSL_PENDING_SESSION;
904 goto err;
905 }
906 ssl->tlsext_ticket_expected = send_new_ticket;
907
908 /* The EMS state is needed when making the resumption decision, but
909 * extensions are not normally parsed until later. This detects the EMS
910 * extension for the resumption decision and it's checked against the result
911 * of the normal parse later in this function. */
912 const uint8_t *ems_data;
913 size_t ems_len;
914 int have_extended_master_secret =
915 ssl->version != SSL3_VERSION &&
916 SSL_early_callback_ctx_extension_get(&early_ctx,
917 TLSEXT_TYPE_extended_master_secret,
918 &ems_data, &ems_len) &&
919 ems_len == 0;
920
921 if (session != NULL) {
922 if (session->extended_master_secret &&
923 !have_extended_master_secret) {
924 /* A ClientHello without EMS that attempts to resume a session with EMS
925 * is fatal to the connection. */
926 al = SSL_AD_HANDSHAKE_FAILURE;
927 OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION);
928 goto f_err;
929 }
930
931 ssl->hit =
932 /* Only resume if the session's version matches the negotiated version:
933 * most clients do not accept a mismatch. */
934 ssl->version == session->ssl_version &&
935 /* If the client offers the EMS extension, but the previous session
936 * didn't use it, then negotiate a new session. */
937 have_extended_master_secret == session->extended_master_secret;
938 }
939
940 if (ssl->hit) {
941 /* Use the new session. */
942 SSL_SESSION_free(ssl->session);
943 ssl->session = session;
944 session = NULL;
945
946 ssl->verify_result = ssl->session->verify_result;
947 } else {
948 if (!ssl_get_new_session(ssl, 1 /* server */)) {
949 goto err;
950 }
951
952 /* Clear the session ID if we want the session to be single-use. */
953 if (!(ssl->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)) {
954 ssl->session->session_id_length = 0;
955 }
956 }
957
958 if (ssl->ctx->dos_protection_cb != NULL &&
959 ssl->ctx->dos_protection_cb(&early_ctx) == 0) {
960 /* Connection rejected for DOS reasons. */
961 al = SSL_AD_ACCESS_DENIED;
962 OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
963 goto f_err;
964 }
965
966 if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) ||
967 CBS_len(&cipher_suites) == 0 ||
968 CBS_len(&cipher_suites) % 2 != 0 ||
969 !CBS_get_u8_length_prefixed(&client_hello, &compression_methods) ||
970 CBS_len(&compression_methods) == 0) {
971 al = SSL_AD_DECODE_ERROR;
972 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
973 goto f_err;
974 }
975
976 ciphers = ssl_bytes_to_cipher_list(ssl, &cipher_suites);
977 if (ciphers == NULL) {
978 goto err;
979 }
980
981 /* If it is a hit, check that the cipher is in the list. */
982 if (ssl->hit) {
983 size_t j;
984 int found_cipher = 0;
985 uint32_t id = ssl->session->cipher->id;
986
987 for (j = 0; j < sk_SSL_CIPHER_num(ciphers); j++) {
988 c = sk_SSL_CIPHER_value(ciphers, j);
989 if (c->id == id) {
990 found_cipher = 1;
991 break;
992 }
993 }
994
995 if (!found_cipher) {
996 /* we need to have the cipher in the cipher list if we are asked to reuse
997 * it */
998 al = SSL_AD_ILLEGAL_PARAMETER;
999 OPENSSL_PUT_ERROR(SSL, SSL_R_REQUIRED_CIPHER_MISSING);
1000 goto f_err;
1001 }
1002 }
1003
1004 /* Only null compression is supported. */
1005 if (memchr(CBS_data(&compression_methods), 0,
1006 CBS_len(&compression_methods)) == NULL) {
1007 al = SSL_AD_ILLEGAL_PARAMETER;
1008 OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMPRESSION_SPECIFIED);
1009 goto f_err;
1010 }
1011
1012 /* TLS extensions. */
1013 if (ssl->version >= SSL3_VERSION &&
1014 !ssl_parse_clienthello_tlsext(ssl, &client_hello)) {
1015 OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
1016 goto err;
1017 }
1018
1019 /* There should be nothing left over in the record. */
1020 if (CBS_len(&client_hello) != 0) {
1021 /* wrong packet length */
1022 al = SSL_AD_DECODE_ERROR;
1023 OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_PACKET_LENGTH);
1024 goto f_err;
1025 }
1026
1027 if (have_extended_master_secret != ssl->s3->tmp.extended_master_secret) {
1028 al = SSL_AD_INTERNAL_ERROR;
1029 OPENSSL_PUT_ERROR(SSL, SSL_R_EMS_STATE_INCONSISTENT);
1030 goto f_err;
1031 }
1032
1033 /* Given ciphers and SSL_get_ciphers, we must pick a cipher */
1034 if (!ssl->hit) {
1035 if (ciphers == NULL) {
1036 al = SSL_AD_ILLEGAL_PARAMETER;
1037 OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CIPHERS_PASSED);
1038 goto f_err;
1039 }
1040
1041 /* Let cert callback update server certificates if required */
1042 if (ssl->cert->cert_cb) {
1043 int rv = ssl->cert->cert_cb(ssl, ssl->cert->cert_cb_arg);
1044 if (rv == 0) {
1045 al = SSL_AD_INTERNAL_ERROR;
1046 OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR);
1047 goto f_err;
1048 }
1049 if (rv < 0) {
1050 ssl->rwstate = SSL_X509_LOOKUP;
1051 goto err;
1052 }
1053 ssl->rwstate = SSL_NOTHING;
1054 }
1055 c = ssl3_choose_cipher(ssl, ciphers, ssl_get_cipher_preferences(ssl));
1056
1057 if (c == NULL) {
1058 al = SSL_AD_HANDSHAKE_FAILURE;
1059 OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_CIPHER);
1060 goto f_err;
1061 }
1062 ssl->s3->tmp.new_cipher = c;
1063
1064 /* Determine whether to request a client certificate. */
1065 ssl->s3->tmp.cert_request = !!(ssl->verify_mode & SSL_VERIFY_PEER);
1066 /* Only request a certificate if Channel ID isn't negotiated. */
1067 if ((ssl->verify_mode & SSL_VERIFY_PEER_IF_NO_OBC) &&
1068 ssl->s3->tlsext_channel_id_valid) {
1069 ssl->s3->tmp.cert_request = 0;
1070 }
1071 /* Plain PSK forbids Certificate and CertificateRequest. */
1072 if (ssl->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK) {
1073 ssl->s3->tmp.cert_request = 0;
1074 }
1075 } else {
1076 /* Session-id reuse */
1077 ssl->s3->tmp.new_cipher = ssl->session->cipher;
1078 ssl->s3->tmp.cert_request = 0;
1079 }
1080
1081 /* Now that the cipher is known, initialize the handshake hash. */
1082 if (!ssl3_init_handshake_hash(ssl)) {
1083 goto f_err;
1084 }
1085
1086 /* In TLS 1.2, client authentication requires hashing the handshake transcript
1087 * under a different hash. Otherwise, release the handshake buffer. */
1088 if (!SSL_USE_SIGALGS(ssl) || !ssl->s3->tmp.cert_request) {
1089 ssl3_free_handshake_buffer(ssl);
1090 }
1091
1092 /* we now have the following setup;
1093 * client_random
1094 * cipher_list - our prefered list of ciphers
1095 * ciphers - the clients prefered list of ciphers
1096 * compression - basically ignored right now
1097 * ssl version is set - sslv3
1098 * ssl->session - The ssl session has been setup.
1099 * ssl->hit - session reuse flag
1100 * ssl->tmp.new_cipher - the new cipher to use. */
1101
1102 ret = 1;
1103
1104 if (0) {
1105 f_err:
1106 ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
1107 }
1108
1109 err:
1110 sk_SSL_CIPHER_free(ciphers);
1111 SSL_SESSION_free(session);
1112 return ret;
1113 }
1114
ssl3_send_server_hello(SSL * ssl)1115 int ssl3_send_server_hello(SSL *ssl) {
1116 if (ssl->state == SSL3_ST_SW_SRVR_HELLO_B) {
1117 return ssl_do_write(ssl);
1118 }
1119
1120 assert(ssl->state == SSL3_ST_SW_SRVR_HELLO_A);
1121
1122 /* We only accept ChannelIDs on connections with ECDHE in order to avoid a
1123 * known attack while we fix ChannelID itself. */
1124 if (ssl->s3->tlsext_channel_id_valid &&
1125 (ssl->s3->tmp.new_cipher->algorithm_mkey & SSL_kECDHE) == 0) {
1126 ssl->s3->tlsext_channel_id_valid = 0;
1127 }
1128
1129 /* If this is a resumption and the original handshake didn't support
1130 * ChannelID then we didn't record the original handshake hashes in the
1131 * session and so cannot resume with ChannelIDs. */
1132 if (ssl->hit && ssl->session->original_handshake_hash_len == 0) {
1133 ssl->s3->tlsext_channel_id_valid = 0;
1134 }
1135
1136 if (!ssl_fill_hello_random(ssl->s3->server_random, SSL3_RANDOM_SIZE,
1137 1 /* server */)) {
1138 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1139 return -1;
1140 }
1141
1142 CBB cbb, session_id;
1143 size_t length;
1144 CBB_zero(&cbb);
1145 if (!CBB_init_fixed(&cbb, ssl_handshake_start(ssl),
1146 ssl->init_buf->max - SSL_HM_HEADER_LENGTH(ssl)) ||
1147 !CBB_add_u16(&cbb, ssl->version) ||
1148 !CBB_add_bytes(&cbb, ssl->s3->server_random, SSL3_RANDOM_SIZE) ||
1149 !CBB_add_u8_length_prefixed(&cbb, &session_id) ||
1150 !CBB_add_bytes(&session_id, ssl->session->session_id,
1151 ssl->session->session_id_length) ||
1152 !CBB_add_u16(&cbb, ssl_cipher_get_value(ssl->s3->tmp.new_cipher)) ||
1153 !CBB_add_u8(&cbb, 0 /* no compression */) ||
1154 !ssl_add_serverhello_tlsext(ssl, &cbb) ||
1155 !CBB_finish(&cbb, NULL, &length) ||
1156 !ssl_set_handshake_header(ssl, SSL3_MT_SERVER_HELLO, length)) {
1157 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1158 CBB_cleanup(&cbb);
1159 return -1;
1160 }
1161
1162 ssl->state = SSL3_ST_SW_SRVR_HELLO_B;
1163 return ssl_do_write(ssl);
1164 }
1165
ssl3_send_certificate_status(SSL * ssl)1166 int ssl3_send_certificate_status(SSL *ssl) {
1167 if (ssl->state == SSL3_ST_SW_CERT_STATUS_A) {
1168 CBB out, ocsp_response;
1169 size_t length;
1170
1171 CBB_zero(&out);
1172 if (!CBB_init_fixed(&out, ssl_handshake_start(ssl),
1173 ssl->init_buf->max - SSL_HM_HEADER_LENGTH(ssl)) ||
1174 !CBB_add_u8(&out, TLSEXT_STATUSTYPE_ocsp) ||
1175 !CBB_add_u24_length_prefixed(&out, &ocsp_response) ||
1176 !CBB_add_bytes(&ocsp_response, ssl->ctx->ocsp_response,
1177 ssl->ctx->ocsp_response_length) ||
1178 !CBB_finish(&out, NULL, &length) ||
1179 !ssl_set_handshake_header(ssl, SSL3_MT_CERTIFICATE_STATUS, length)) {
1180 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1181 CBB_cleanup(&out);
1182 return -1;
1183 }
1184
1185 ssl->state = SSL3_ST_SW_CERT_STATUS_B;
1186 }
1187
1188 /* SSL3_ST_SW_CERT_STATUS_B */
1189 return ssl_do_write(ssl);
1190 }
1191
ssl3_send_server_done(SSL * ssl)1192 int ssl3_send_server_done(SSL *ssl) {
1193 if (ssl->state == SSL3_ST_SW_SRVR_DONE_A) {
1194 if (!ssl_set_handshake_header(ssl, SSL3_MT_SERVER_DONE, 0)) {
1195 return -1;
1196 }
1197 ssl->state = SSL3_ST_SW_SRVR_DONE_B;
1198 }
1199
1200 /* SSL3_ST_SW_SRVR_DONE_B */
1201 return ssl_do_write(ssl);
1202 }
1203
ssl3_send_server_key_exchange(SSL * ssl)1204 int ssl3_send_server_key_exchange(SSL *ssl) {
1205 if (ssl->state == SSL3_ST_SW_KEY_EXCH_C) {
1206 return ssl_do_write(ssl);
1207 }
1208
1209 CBB cbb, child;
1210 if (!CBB_init_fixed(&cbb, ssl_handshake_start(ssl),
1211 ssl->init_buf->max - SSL_HM_HEADER_LENGTH(ssl))) {
1212 goto err;
1213 }
1214
1215 if (ssl->state == SSL3_ST_SW_KEY_EXCH_A) {
1216 /* This is the first iteration, so write parameters. */
1217 uint32_t alg_k = ssl->s3->tmp.new_cipher->algorithm_mkey;
1218 uint32_t alg_a = ssl->s3->tmp.new_cipher->algorithm_auth;
1219
1220 /* PSK ciphers begin with an identity hint. */
1221 if (alg_a & SSL_aPSK) {
1222 size_t len =
1223 (ssl->psk_identity_hint == NULL) ? 0 : strlen(ssl->psk_identity_hint);
1224 if (!CBB_add_u16_length_prefixed(&cbb, &child) ||
1225 !CBB_add_bytes(&child, (const uint8_t *)ssl->psk_identity_hint,
1226 len)) {
1227 goto err;
1228 }
1229 }
1230
1231 if (alg_k & SSL_kDHE) {
1232 /* Determine the group to use. */
1233 DH *params = ssl->cert->dh_tmp;
1234 if (params == NULL && ssl->cert->dh_tmp_cb != NULL) {
1235 params = ssl->cert->dh_tmp_cb(ssl, 0, 1024);
1236 }
1237 if (params == NULL) {
1238 OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_TMP_DH_KEY);
1239 ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
1240 goto err;
1241 }
1242 ssl->session->key_exchange_info = DH_num_bits(params);
1243
1244 /* Set up DH, generate a key, and emit the public half. */
1245 DH *dh = DHparams_dup(params);
1246 if (dh == NULL) {
1247 goto err;
1248 }
1249
1250 SSL_ECDH_CTX_init_for_dhe(&ssl->s3->tmp.ecdh_ctx, dh);
1251 if (!CBB_add_u16_length_prefixed(&cbb, &child) ||
1252 !BN_bn2cbb_padded(&child, BN_num_bytes(params->p), params->p) ||
1253 !CBB_add_u16_length_prefixed(&cbb, &child) ||
1254 !BN_bn2cbb_padded(&child, BN_num_bytes(params->g), params->g) ||
1255 !CBB_add_u16_length_prefixed(&cbb, &child) ||
1256 !SSL_ECDH_CTX_generate_keypair(&ssl->s3->tmp.ecdh_ctx, &child)) {
1257 goto err;
1258 }
1259 } else if (alg_k & SSL_kECDHE) {
1260 /* Determine the curve to use. */
1261 uint16_t curve_id;
1262 if (!tls1_get_shared_curve(ssl, &curve_id)) {
1263 OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_TMP_ECDH_KEY);
1264 ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
1265 goto err;
1266 }
1267 ssl->session->key_exchange_info = curve_id;
1268
1269 /* Set up ECDH, generate a key, and emit the public half. */
1270 if (!SSL_ECDH_CTX_init(&ssl->s3->tmp.ecdh_ctx, curve_id) ||
1271 !CBB_add_u8(&cbb, NAMED_CURVE_TYPE) ||
1272 !CBB_add_u16(&cbb, curve_id) ||
1273 !CBB_add_u8_length_prefixed(&cbb, &child) ||
1274 !SSL_ECDH_CTX_generate_keypair(&ssl->s3->tmp.ecdh_ctx, &child)) {
1275 goto err;
1276 }
1277 } else {
1278 assert(alg_k & SSL_kPSK);
1279 }
1280
1281 /* Otherwise, restore |cbb| from the previous iteration.
1282 * TODO(davidben): When |ssl->init_buf| is gone, come up with a simpler
1283 * pattern. Probably keep the |CBB| around in the handshake state. */
1284 } else if (!CBB_did_write(&cbb, ssl->init_num - SSL_HM_HEADER_LENGTH(ssl))) {
1285 goto err;
1286 }
1287
1288 /* Add a signature. */
1289 if (ssl_cipher_has_server_public_key(ssl->s3->tmp.new_cipher)) {
1290 if (!ssl_has_private_key(ssl)) {
1291 ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
1292 goto err;
1293 }
1294
1295 const size_t max_sig_len = ssl_private_key_max_signature_len(ssl);
1296 size_t sig_len;
1297 enum ssl_private_key_result_t sign_result;
1298 if (ssl->state == SSL3_ST_SW_KEY_EXCH_A) {
1299 /* This is the first iteration, so set up the signature. Sample the
1300 * parameter length before adding a signature algorithm. */
1301 if (!CBB_flush(&cbb)) {
1302 goto err;
1303 }
1304 size_t params_len = CBB_len(&cbb);
1305
1306 /* Determine signature algorithm. */
1307 const EVP_MD *md;
1308 if (SSL_USE_SIGALGS(ssl)) {
1309 md = tls1_choose_signing_digest(ssl);
1310 if (!tls12_add_sigandhash(ssl, &cbb, md)) {
1311 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1312 ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
1313 goto err;
1314 }
1315 } else if (ssl_private_key_type(ssl) == EVP_PKEY_RSA) {
1316 md = EVP_md5_sha1();
1317 } else {
1318 md = EVP_sha1();
1319 }
1320
1321 /* Compute the digest and sign it. */
1322 uint8_t digest[EVP_MAX_MD_SIZE];
1323 unsigned digest_len = 0;
1324 EVP_MD_CTX md_ctx;
1325 EVP_MD_CTX_init(&md_ctx);
1326 int digest_ret =
1327 EVP_DigestInit_ex(&md_ctx, md, NULL) &&
1328 EVP_DigestUpdate(&md_ctx, ssl->s3->client_random, SSL3_RANDOM_SIZE) &&
1329 EVP_DigestUpdate(&md_ctx, ssl->s3->server_random, SSL3_RANDOM_SIZE) &&
1330 EVP_DigestUpdate(&md_ctx, CBB_data(&cbb), params_len) &&
1331 EVP_DigestFinal_ex(&md_ctx, digest, &digest_len);
1332 EVP_MD_CTX_cleanup(&md_ctx);
1333 uint8_t *ptr;
1334 if (!digest_ret ||
1335 !CBB_add_u16_length_prefixed(&cbb, &child) ||
1336 !CBB_reserve(&child, &ptr, max_sig_len)) {
1337 goto err;
1338 }
1339 sign_result = ssl_private_key_sign(ssl, ptr, &sig_len, max_sig_len, md,
1340 digest, digest_len);
1341 } else {
1342 assert(ssl->state == SSL3_ST_SW_KEY_EXCH_B);
1343
1344 /* Retry the signature. */
1345 uint8_t *ptr;
1346 if (!CBB_add_u16_length_prefixed(&cbb, &child) ||
1347 !CBB_reserve(&child, &ptr, max_sig_len)) {
1348 goto err;
1349 }
1350 sign_result =
1351 ssl_private_key_sign_complete(ssl, ptr, &sig_len, max_sig_len);
1352 }
1353
1354 switch (sign_result) {
1355 case ssl_private_key_success:
1356 ssl->rwstate = SSL_NOTHING;
1357 if (!CBB_did_write(&child, sig_len)) {
1358 goto err;
1359 }
1360 break;
1361 case ssl_private_key_failure:
1362 ssl->rwstate = SSL_NOTHING;
1363 goto err;
1364 case ssl_private_key_retry:
1365 /* Discard the unfinished signature and save the state of |cbb| for the
1366 * next iteration. */
1367 CBB_discard_child(&cbb);
1368 ssl->init_num = SSL_HM_HEADER_LENGTH(ssl) + CBB_len(&cbb);
1369 ssl->rwstate = SSL_PRIVATE_KEY_OPERATION;
1370 ssl->state = SSL3_ST_SW_KEY_EXCH_B;
1371 goto err;
1372 }
1373 }
1374
1375 size_t length;
1376 if (!CBB_finish(&cbb, NULL, &length) ||
1377 !ssl_set_handshake_header(ssl, SSL3_MT_SERVER_KEY_EXCHANGE, length)) {
1378 goto err;
1379 }
1380 ssl->state = SSL3_ST_SW_KEY_EXCH_C;
1381 return ssl_do_write(ssl);
1382
1383 err:
1384 CBB_cleanup(&cbb);
1385 return -1;
1386 }
1387
ssl3_send_certificate_request(SSL * ssl)1388 int ssl3_send_certificate_request(SSL *ssl) {
1389 uint8_t *p, *d;
1390 size_t i;
1391 int j, nl, off, n;
1392 STACK_OF(X509_NAME) *sk = NULL;
1393 X509_NAME *name;
1394 BUF_MEM *buf;
1395
1396 if (ssl->state == SSL3_ST_SW_CERT_REQ_A) {
1397 buf = ssl->init_buf;
1398
1399 d = p = ssl_handshake_start(ssl);
1400
1401 /* get the list of acceptable cert types */
1402 p++;
1403 n = ssl3_get_req_cert_type(ssl, p);
1404 d[0] = n;
1405 p += n;
1406 n++;
1407
1408 if (SSL_USE_SIGALGS(ssl)) {
1409 const uint8_t *psigs;
1410 nl = tls12_get_psigalgs(ssl, &psigs);
1411 s2n(nl, p);
1412 memcpy(p, psigs, nl);
1413 p += nl;
1414 n += nl + 2;
1415 }
1416
1417 off = n;
1418 p += 2;
1419 n += 2;
1420
1421 sk = SSL_get_client_CA_list(ssl);
1422 nl = 0;
1423 if (sk != NULL) {
1424 for (i = 0; i < sk_X509_NAME_num(sk); i++) {
1425 name = sk_X509_NAME_value(sk, i);
1426 j = i2d_X509_NAME(name, NULL);
1427 if (!BUF_MEM_grow_clean(buf, SSL_HM_HEADER_LENGTH(ssl) + n + j + 2)) {
1428 OPENSSL_PUT_ERROR(SSL, ERR_R_BUF_LIB);
1429 goto err;
1430 }
1431 p = ssl_handshake_start(ssl) + n;
1432 s2n(j, p);
1433 i2d_X509_NAME(name, &p);
1434 n += 2 + j;
1435 nl += 2 + j;
1436 }
1437 }
1438
1439 /* else no CA names */
1440 p = ssl_handshake_start(ssl) + off;
1441 s2n(nl, p);
1442
1443 if (!ssl_set_handshake_header(ssl, SSL3_MT_CERTIFICATE_REQUEST, n)) {
1444 goto err;
1445 }
1446 ssl->state = SSL3_ST_SW_CERT_REQ_B;
1447 }
1448
1449 /* SSL3_ST_SW_CERT_REQ_B */
1450 return ssl_do_write(ssl);
1451
1452 err:
1453 return -1;
1454 }
1455
ssl3_get_client_key_exchange(SSL * ssl)1456 int ssl3_get_client_key_exchange(SSL *ssl) {
1457 int al;
1458 CBS client_key_exchange;
1459 uint32_t alg_k;
1460 uint32_t alg_a;
1461 uint8_t *premaster_secret = NULL;
1462 size_t premaster_secret_len = 0;
1463 uint8_t *decrypt_buf = NULL;
1464
1465 unsigned psk_len = 0;
1466 uint8_t psk[PSK_MAX_PSK_LEN];
1467
1468 if (ssl->state == SSL3_ST_SR_KEY_EXCH_A ||
1469 ssl->state == SSL3_ST_SR_KEY_EXCH_B) {
1470 int ok;
1471 const long n = ssl->method->ssl_get_message(
1472 ssl, SSL3_ST_SR_KEY_EXCH_A, SSL3_ST_SR_KEY_EXCH_B,
1473 SSL3_MT_CLIENT_KEY_EXCHANGE, 2048 /* ??? */, ssl_hash_message, &ok);
1474 if (!ok) {
1475 return n;
1476 }
1477 }
1478
1479 CBS_init(&client_key_exchange, ssl->init_msg, ssl->init_num);
1480 alg_k = ssl->s3->tmp.new_cipher->algorithm_mkey;
1481 alg_a = ssl->s3->tmp.new_cipher->algorithm_auth;
1482
1483 /* If using a PSK key exchange, prepare the pre-shared key. */
1484 if (alg_a & SSL_aPSK) {
1485 CBS psk_identity;
1486
1487 /* If using PSK, the ClientKeyExchange contains a psk_identity. If PSK,
1488 * then this is the only field in the message. */
1489 if (!CBS_get_u16_length_prefixed(&client_key_exchange, &psk_identity) ||
1490 ((alg_k & SSL_kPSK) && CBS_len(&client_key_exchange) != 0)) {
1491 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1492 al = SSL_AD_DECODE_ERROR;
1493 goto f_err;
1494 }
1495
1496 if (ssl->psk_server_callback == NULL) {
1497 OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_NO_SERVER_CB);
1498 al = SSL_AD_INTERNAL_ERROR;
1499 goto f_err;
1500 }
1501
1502 if (CBS_len(&psk_identity) > PSK_MAX_IDENTITY_LEN ||
1503 CBS_contains_zero_byte(&psk_identity)) {
1504 OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG);
1505 al = SSL_AD_ILLEGAL_PARAMETER;
1506 goto f_err;
1507 }
1508
1509 if (!CBS_strdup(&psk_identity, &ssl->session->psk_identity)) {
1510 al = SSL_AD_INTERNAL_ERROR;
1511 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
1512 goto f_err;
1513 }
1514
1515 /* Look up the key for the identity. */
1516 psk_len = ssl->psk_server_callback(ssl, ssl->session->psk_identity, psk,
1517 sizeof(psk));
1518 if (psk_len > PSK_MAX_PSK_LEN) {
1519 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1520 al = SSL_AD_INTERNAL_ERROR;
1521 goto f_err;
1522 } else if (psk_len == 0) {
1523 /* PSK related to the given identity not found */
1524 OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_NOT_FOUND);
1525 al = SSL_AD_UNKNOWN_PSK_IDENTITY;
1526 goto f_err;
1527 }
1528 }
1529
1530 /* Depending on the key exchange method, compute |premaster_secret| and
1531 * |premaster_secret_len|. */
1532 if (alg_k & SSL_kRSA) {
1533 /* Allocate a buffer large enough for an RSA decryption. */
1534 const size_t rsa_size = ssl_private_key_max_signature_len(ssl);
1535 decrypt_buf = OPENSSL_malloc(rsa_size);
1536 if (decrypt_buf == NULL) {
1537 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
1538 goto err;
1539 }
1540
1541 enum ssl_private_key_result_t decrypt_result;
1542 size_t decrypt_len;
1543 if (ssl->state == SSL3_ST_SR_KEY_EXCH_B) {
1544 if (!ssl_has_private_key(ssl) ||
1545 ssl_private_key_type(ssl) != EVP_PKEY_RSA) {
1546 al = SSL_AD_HANDSHAKE_FAILURE;
1547 OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_RSA_CERTIFICATE);
1548 goto f_err;
1549 }
1550 CBS encrypted_premaster_secret;
1551 if (ssl->version > SSL3_VERSION) {
1552 if (!CBS_get_u16_length_prefixed(&client_key_exchange,
1553 &encrypted_premaster_secret) ||
1554 CBS_len(&client_key_exchange) != 0) {
1555 al = SSL_AD_DECODE_ERROR;
1556 OPENSSL_PUT_ERROR(SSL,
1557 SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG);
1558 goto f_err;
1559 }
1560 } else {
1561 encrypted_premaster_secret = client_key_exchange;
1562 }
1563
1564 /* Decrypt with no padding. PKCS#1 padding will be removed as part of the
1565 * timing-sensitive code below. */
1566 decrypt_result = ssl_private_key_decrypt(
1567 ssl, decrypt_buf, &decrypt_len, rsa_size,
1568 CBS_data(&encrypted_premaster_secret),
1569 CBS_len(&encrypted_premaster_secret));
1570 } else {
1571 assert(ssl->state == SSL3_ST_SR_KEY_EXCH_C);
1572 /* Complete async decrypt. */
1573 decrypt_result = ssl_private_key_decrypt_complete(
1574 ssl, decrypt_buf, &decrypt_len, rsa_size);
1575 }
1576
1577 switch (decrypt_result) {
1578 case ssl_private_key_success:
1579 ssl->rwstate = SSL_NOTHING;
1580 break;
1581 case ssl_private_key_failure:
1582 ssl->rwstate = SSL_NOTHING;
1583 goto err;
1584 case ssl_private_key_retry:
1585 ssl->rwstate = SSL_PRIVATE_KEY_OPERATION;
1586 ssl->state = SSL3_ST_SR_KEY_EXCH_C;
1587 goto err;
1588 }
1589
1590 assert(decrypt_len == rsa_size);
1591
1592 /* Prepare a random premaster, to be used on invalid padding. See RFC 5246,
1593 * section 7.4.7.1. */
1594 premaster_secret_len = SSL_MAX_MASTER_KEY_LENGTH;
1595 premaster_secret = OPENSSL_malloc(premaster_secret_len);
1596 if (premaster_secret == NULL) {
1597 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
1598 goto err;
1599 }
1600 if (!RAND_bytes(premaster_secret, premaster_secret_len)) {
1601 goto err;
1602 }
1603
1604 /* The smallest padded premaster is 11 bytes of overhead. Small keys are
1605 * publicly invalid. */
1606 if (decrypt_len < 11 + premaster_secret_len) {
1607 al = SSL_AD_DECRYPT_ERROR;
1608 OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED);
1609 goto f_err;
1610 }
1611
1612 /* Check the padding. See RFC 3447, section 7.2.2. */
1613 size_t padding_len = decrypt_len - premaster_secret_len;
1614 uint8_t good = constant_time_eq_int_8(decrypt_buf[0], 0) &
1615 constant_time_eq_int_8(decrypt_buf[1], 2);
1616 size_t i;
1617 for (i = 2; i < padding_len - 1; i++) {
1618 good &= ~constant_time_is_zero_8(decrypt_buf[i]);
1619 }
1620 good &= constant_time_is_zero_8(decrypt_buf[padding_len - 1]);
1621
1622 /* The premaster secret must begin with |client_version|. This too must be
1623 * checked in constant time (http://eprint.iacr.org/2003/052/). */
1624 good &= constant_time_eq_8(decrypt_buf[padding_len],
1625 (unsigned)(ssl->client_version >> 8));
1626 good &= constant_time_eq_8(decrypt_buf[padding_len + 1],
1627 (unsigned)(ssl->client_version & 0xff));
1628
1629 /* Select, in constant time, either the decrypted premaster or the random
1630 * premaster based on |good|. */
1631 for (i = 0; i < premaster_secret_len; i++) {
1632 premaster_secret[i] = constant_time_select_8(
1633 good, decrypt_buf[padding_len + i], premaster_secret[i]);
1634 }
1635
1636 OPENSSL_free(decrypt_buf);
1637 decrypt_buf = NULL;
1638 } else if (alg_k & (SSL_kECDHE|SSL_kDHE)) {
1639 /* Parse the ClientKeyExchange. ECDHE uses a u8 length prefix while DHE uses
1640 * u16. */
1641 CBS peer_key;
1642 int peer_key_ok;
1643 if (alg_k & SSL_kECDHE) {
1644 peer_key_ok = CBS_get_u8_length_prefixed(&client_key_exchange, &peer_key);
1645 } else {
1646 peer_key_ok =
1647 CBS_get_u16_length_prefixed(&client_key_exchange, &peer_key);
1648 }
1649
1650 if (!peer_key_ok || CBS_len(&client_key_exchange) != 0) {
1651 al = SSL_AD_DECODE_ERROR;
1652 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1653 goto f_err;
1654 }
1655
1656 /* Compute the premaster. */
1657 uint8_t alert;
1658 if (!SSL_ECDH_CTX_compute_secret(&ssl->s3->tmp.ecdh_ctx, &premaster_secret,
1659 &premaster_secret_len, &alert,
1660 CBS_data(&peer_key), CBS_len(&peer_key))) {
1661 al = alert;
1662 goto f_err;
1663 }
1664
1665 /* The key exchange state may now be discarded. */
1666 SSL_ECDH_CTX_cleanup(&ssl->s3->tmp.ecdh_ctx);
1667 } else if (alg_k & SSL_kPSK) {
1668 /* For plain PSK, other_secret is a block of 0s with the same length as the
1669 * pre-shared key. */
1670 premaster_secret_len = psk_len;
1671 premaster_secret = OPENSSL_malloc(premaster_secret_len);
1672 if (premaster_secret == NULL) {
1673 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
1674 goto err;
1675 }
1676 memset(premaster_secret, 0, premaster_secret_len);
1677 } else {
1678 al = SSL_AD_HANDSHAKE_FAILURE;
1679 OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CIPHER_TYPE);
1680 goto f_err;
1681 }
1682
1683 /* For a PSK cipher suite, the actual pre-master secret is combined with the
1684 * pre-shared key. */
1685 if (alg_a & SSL_aPSK) {
1686 CBB new_premaster, child;
1687 uint8_t *new_data;
1688 size_t new_len;
1689
1690 CBB_zero(&new_premaster);
1691 if (!CBB_init(&new_premaster, 2 + psk_len + 2 + premaster_secret_len) ||
1692 !CBB_add_u16_length_prefixed(&new_premaster, &child) ||
1693 !CBB_add_bytes(&child, premaster_secret, premaster_secret_len) ||
1694 !CBB_add_u16_length_prefixed(&new_premaster, &child) ||
1695 !CBB_add_bytes(&child, psk, psk_len) ||
1696 !CBB_finish(&new_premaster, &new_data, &new_len)) {
1697 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
1698 CBB_cleanup(&new_premaster);
1699 goto err;
1700 }
1701
1702 OPENSSL_cleanse(premaster_secret, premaster_secret_len);
1703 OPENSSL_free(premaster_secret);
1704 premaster_secret = new_data;
1705 premaster_secret_len = new_len;
1706 }
1707
1708 /* Compute the master secret */
1709 ssl->session->master_key_length = ssl->enc_method->generate_master_secret(
1710 ssl, ssl->session->master_key, premaster_secret, premaster_secret_len);
1711 if (ssl->session->master_key_length == 0) {
1712 goto err;
1713 }
1714 ssl->session->extended_master_secret = ssl->s3->tmp.extended_master_secret;
1715
1716 OPENSSL_cleanse(premaster_secret, premaster_secret_len);
1717 OPENSSL_free(premaster_secret);
1718 return 1;
1719
1720 f_err:
1721 ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
1722 err:
1723 if (premaster_secret != NULL) {
1724 OPENSSL_cleanse(premaster_secret, premaster_secret_len);
1725 OPENSSL_free(premaster_secret);
1726 }
1727 OPENSSL_free(decrypt_buf);
1728
1729 return -1;
1730 }
1731
ssl3_get_cert_verify(SSL * ssl)1732 int ssl3_get_cert_verify(SSL *ssl) {
1733 int al, ok, ret = 0;
1734 long n;
1735 CBS certificate_verify, signature;
1736 X509 *peer = ssl->session->peer;
1737 EVP_PKEY *pkey = NULL;
1738 const EVP_MD *md = NULL;
1739 uint8_t digest[EVP_MAX_MD_SIZE];
1740 size_t digest_length;
1741 EVP_PKEY_CTX *pctx = NULL;
1742
1743 /* Only RSA and ECDSA client certificates are supported, so a
1744 * CertificateVerify is required if and only if there's a client certificate.
1745 * */
1746 if (peer == NULL) {
1747 ssl3_free_handshake_buffer(ssl);
1748 return 1;
1749 }
1750
1751 n = ssl->method->ssl_get_message(
1752 ssl, SSL3_ST_SR_CERT_VRFY_A, SSL3_ST_SR_CERT_VRFY_B,
1753 SSL3_MT_CERTIFICATE_VERIFY, SSL3_RT_MAX_PLAIN_LENGTH,
1754 ssl_dont_hash_message, &ok);
1755
1756 if (!ok) {
1757 return n;
1758 }
1759
1760 /* Filter out unsupported certificate types. */
1761 pkey = X509_get_pubkey(peer);
1762 if (pkey == NULL) {
1763 goto err;
1764 }
1765 if (!(X509_certificate_type(peer, pkey) & EVP_PKT_SIGN) ||
1766 (pkey->type != EVP_PKEY_RSA && pkey->type != EVP_PKEY_EC)) {
1767 al = SSL_AD_UNSUPPORTED_CERTIFICATE;
1768 OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE);
1769 goto f_err;
1770 }
1771
1772 CBS_init(&certificate_verify, ssl->init_msg, n);
1773
1774 /* Determine the digest type if needbe. */
1775 if (SSL_USE_SIGALGS(ssl)) {
1776 uint8_t hash, signature_type;
1777 if (!CBS_get_u8(&certificate_verify, &hash) ||
1778 !CBS_get_u8(&certificate_verify, &signature_type)) {
1779 al = SSL_AD_DECODE_ERROR;
1780 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1781 goto f_err;
1782 }
1783 if (!tls12_check_peer_sigalg(ssl, &md, &al, hash, signature_type, pkey)) {
1784 goto f_err;
1785 }
1786 }
1787
1788 /* Compute the digest. */
1789 if (!ssl3_cert_verify_hash(ssl, digest, &digest_length, &md, pkey->type)) {
1790 goto err;
1791 }
1792
1793 /* The handshake buffer is no longer necessary, and we may hash the current
1794 * message.*/
1795 ssl3_free_handshake_buffer(ssl);
1796 if (!ssl3_hash_current_message(ssl)) {
1797 goto err;
1798 }
1799
1800 /* Parse and verify the signature. */
1801 if (!CBS_get_u16_length_prefixed(&certificate_verify, &signature) ||
1802 CBS_len(&certificate_verify) != 0) {
1803 al = SSL_AD_DECODE_ERROR;
1804 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1805 goto f_err;
1806 }
1807
1808 pctx = EVP_PKEY_CTX_new(pkey, NULL);
1809 if (pctx == NULL) {
1810 goto err;
1811 }
1812 if (!EVP_PKEY_verify_init(pctx) ||
1813 !EVP_PKEY_CTX_set_signature_md(pctx, md) ||
1814 !EVP_PKEY_verify(pctx, CBS_data(&signature), CBS_len(&signature), digest,
1815 digest_length)) {
1816 al = SSL_AD_DECRYPT_ERROR;
1817 OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SIGNATURE);
1818 goto f_err;
1819 }
1820
1821 ret = 1;
1822
1823 if (0) {
1824 f_err:
1825 ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
1826 }
1827
1828 err:
1829 EVP_PKEY_CTX_free(pctx);
1830 EVP_PKEY_free(pkey);
1831
1832 return ret;
1833 }
1834
ssl3_get_client_certificate(SSL * ssl)1835 int ssl3_get_client_certificate(SSL *ssl) {
1836 int i, ok, al, ret = -1;
1837 X509 *x = NULL;
1838 unsigned long n;
1839 STACK_OF(X509) *sk = NULL;
1840 SHA256_CTX sha256;
1841 CBS certificate_msg, certificate_list;
1842 int is_first_certificate = 1;
1843
1844 n = ssl->method->ssl_get_message(ssl, SSL3_ST_SR_CERT_A, SSL3_ST_SR_CERT_B,
1845 -1, (long)ssl->max_cert_list,
1846 ssl_hash_message, &ok);
1847
1848 if (!ok) {
1849 return n;
1850 }
1851
1852 if (ssl->s3->tmp.message_type == SSL3_MT_CLIENT_KEY_EXCHANGE) {
1853 if ((ssl->verify_mode & SSL_VERIFY_PEER) &&
1854 (ssl->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
1855 OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
1856 al = SSL_AD_HANDSHAKE_FAILURE;
1857 goto f_err;
1858 }
1859
1860 /* If tls asked for a client cert, the client must return a 0 list */
1861 if (ssl->version > SSL3_VERSION && ssl->s3->tmp.cert_request) {
1862 OPENSSL_PUT_ERROR(SSL,
1863 SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST);
1864 al = SSL_AD_UNEXPECTED_MESSAGE;
1865 goto f_err;
1866 }
1867 ssl->s3->tmp.reuse_message = 1;
1868
1869 return 1;
1870 }
1871
1872 if (ssl->s3->tmp.message_type != SSL3_MT_CERTIFICATE) {
1873 al = SSL_AD_UNEXPECTED_MESSAGE;
1874 OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_MESSAGE_TYPE);
1875 goto f_err;
1876 }
1877
1878 CBS_init(&certificate_msg, ssl->init_msg, n);
1879
1880 sk = sk_X509_new_null();
1881 if (sk == NULL) {
1882 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
1883 goto err;
1884 }
1885
1886 if (!CBS_get_u24_length_prefixed(&certificate_msg, &certificate_list) ||
1887 CBS_len(&certificate_msg) != 0) {
1888 al = SSL_AD_DECODE_ERROR;
1889 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1890 goto f_err;
1891 }
1892
1893 while (CBS_len(&certificate_list) > 0) {
1894 CBS certificate;
1895 const uint8_t *data;
1896
1897 if (!CBS_get_u24_length_prefixed(&certificate_list, &certificate)) {
1898 al = SSL_AD_DECODE_ERROR;
1899 OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1900 goto f_err;
1901 }
1902
1903 if (is_first_certificate && ssl->ctx->retain_only_sha256_of_client_certs) {
1904 /* If this is the first certificate, and we don't want to keep peer
1905 * certificates in memory, then we hash it right away. */
1906 SHA256_Init(&sha256);
1907 SHA256_Update(&sha256, CBS_data(&certificate), CBS_len(&certificate));
1908 SHA256_Final(ssl->session->peer_sha256, &sha256);
1909 ssl->session->peer_sha256_valid = 1;
1910 }
1911 is_first_certificate = 0;
1912
1913 /* A u24 length cannot overflow a long. */
1914 data = CBS_data(&certificate);
1915 x = d2i_X509(NULL, &data, (long)CBS_len(&certificate));
1916 if (x == NULL) {
1917 al = SSL_AD_BAD_CERTIFICATE;
1918 OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
1919 goto f_err;
1920 }
1921 if (data != CBS_data(&certificate) + CBS_len(&certificate)) {
1922 al = SSL_AD_DECODE_ERROR;
1923 OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_LENGTH_MISMATCH);
1924 goto f_err;
1925 }
1926 if (!sk_X509_push(sk, x)) {
1927 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
1928 goto err;
1929 }
1930 x = NULL;
1931 }
1932
1933 if (sk_X509_num(sk) <= 0) {
1934 /* No client certificate so the handshake buffer may be discarded. */
1935 ssl3_free_handshake_buffer(ssl);
1936
1937 /* TLS does not mind 0 certs returned */
1938 if (ssl->version == SSL3_VERSION) {
1939 al = SSL_AD_HANDSHAKE_FAILURE;
1940 OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATES_RETURNED);
1941 goto f_err;
1942 } else if ((ssl->verify_mode & SSL_VERIFY_PEER) &&
1943 (ssl->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
1944 /* Fail for TLS only if we required a certificate */
1945 OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
1946 al = SSL_AD_HANDSHAKE_FAILURE;
1947 goto f_err;
1948 }
1949 } else {
1950 i = ssl_verify_cert_chain(ssl, sk);
1951 if (i <= 0) {
1952 al = ssl_verify_alarm_type(ssl->verify_result);
1953 OPENSSL_PUT_ERROR(SSL, SSL_R_CERTIFICATE_VERIFY_FAILED);
1954 goto f_err;
1955 }
1956 }
1957
1958 X509_free(ssl->session->peer);
1959 ssl->session->peer = sk_X509_shift(sk);
1960 ssl->session->verify_result = ssl->verify_result;
1961
1962 sk_X509_pop_free(ssl->session->cert_chain, X509_free);
1963 ssl->session->cert_chain = sk;
1964 /* Inconsistency alert: cert_chain does *not* include the peer's own
1965 * certificate, while we do include it in s3_clnt.c */
1966
1967 sk = NULL;
1968
1969 ret = 1;
1970
1971 if (0) {
1972 f_err:
1973 ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
1974 }
1975
1976 err:
1977 X509_free(x);
1978 sk_X509_pop_free(sk, X509_free);
1979 return ret;
1980 }
1981
ssl3_send_server_certificate(SSL * ssl)1982 int ssl3_send_server_certificate(SSL *ssl) {
1983 if (ssl->state == SSL3_ST_SW_CERT_A) {
1984 if (!ssl3_output_cert_chain(ssl)) {
1985 return 0;
1986 }
1987 ssl->state = SSL3_ST_SW_CERT_B;
1988 }
1989
1990 /* SSL3_ST_SW_CERT_B */
1991 return ssl_do_write(ssl);
1992 }
1993
1994 /* send a new session ticket (not necessarily for a new session) */
ssl3_send_new_session_ticket(SSL * ssl)1995 int ssl3_send_new_session_ticket(SSL *ssl) {
1996 int ret = -1;
1997 uint8_t *session = NULL;
1998 size_t session_len;
1999 EVP_CIPHER_CTX ctx;
2000 HMAC_CTX hctx;
2001
2002 EVP_CIPHER_CTX_init(&ctx);
2003 HMAC_CTX_init(&hctx);
2004
2005 if (ssl->state == SSL3_ST_SW_SESSION_TICKET_A) {
2006 uint8_t *p, *macstart;
2007 int len;
2008 unsigned int hlen;
2009 SSL_CTX *tctx = ssl->initial_ctx;
2010 uint8_t iv[EVP_MAX_IV_LENGTH];
2011 uint8_t key_name[16];
2012 /* The maximum overhead of encrypting the session is 16 (key name) + IV +
2013 * one block of encryption overhead + HMAC. */
2014 const size_t max_ticket_overhead =
2015 16 + EVP_MAX_IV_LENGTH + EVP_MAX_BLOCK_LENGTH + EVP_MAX_MD_SIZE;
2016
2017 /* Serialize the SSL_SESSION to be encoded into the ticket. */
2018 if (!SSL_SESSION_to_bytes_for_ticket(ssl->session, &session,
2019 &session_len)) {
2020 goto err;
2021 }
2022
2023 /* If the session is too long, emit a dummy value rather than abort the
2024 * connection. */
2025 if (session_len > 0xFFFF - max_ticket_overhead) {
2026 static const char kTicketPlaceholder[] = "TICKET TOO LARGE";
2027 const size_t placeholder_len = strlen(kTicketPlaceholder);
2028
2029 OPENSSL_free(session);
2030 session = NULL;
2031
2032 p = ssl_handshake_start(ssl);
2033 /* Emit ticket_lifetime_hint. */
2034 l2n(0, p);
2035 /* Emit ticket. */
2036 s2n(placeholder_len, p);
2037 memcpy(p, kTicketPlaceholder, placeholder_len);
2038 p += placeholder_len;
2039
2040 len = p - ssl_handshake_start(ssl);
2041 if (!ssl_set_handshake_header(ssl, SSL3_MT_NEWSESSION_TICKET, len)) {
2042 goto err;
2043 }
2044 ssl->state = SSL3_ST_SW_SESSION_TICKET_B;
2045 return ssl_do_write(ssl);
2046 }
2047
2048 /* Grow buffer if need be: the length calculation is as follows:
2049 * handshake_header_length + 4 (ticket lifetime hint) + 2 (ticket length) +
2050 * max_ticket_overhead + * session_length */
2051 if (!BUF_MEM_grow(ssl->init_buf, SSL_HM_HEADER_LENGTH(ssl) + 6 +
2052 max_ticket_overhead + session_len)) {
2053 goto err;
2054 }
2055 p = ssl_handshake_start(ssl);
2056 /* Initialize HMAC and cipher contexts. If callback present it does all the
2057 * work otherwise use generated values from parent ctx. */
2058 if (tctx->tlsext_ticket_key_cb) {
2059 if (tctx->tlsext_ticket_key_cb(ssl, key_name, iv, &ctx, &hctx,
2060 1 /* encrypt */) < 0) {
2061 goto err;
2062 }
2063 } else {
2064 if (!RAND_bytes(iv, 16) ||
2065 !EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
2066 tctx->tlsext_tick_aes_key, iv) ||
2067 !HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16, tlsext_tick_md(),
2068 NULL)) {
2069 goto err;
2070 }
2071 memcpy(key_name, tctx->tlsext_tick_key_name, 16);
2072 }
2073
2074 /* Ticket lifetime hint (advisory only): We leave this unspecified for
2075 * resumed session (for simplicity), and guess that tickets for new
2076 * sessions will live as long as their sessions. */
2077 l2n(ssl->hit ? 0 : ssl->session->timeout, p);
2078
2079 /* Skip ticket length for now */
2080 p += 2;
2081 /* Output key name */
2082 macstart = p;
2083 memcpy(p, key_name, 16);
2084 p += 16;
2085 /* output IV */
2086 memcpy(p, iv, EVP_CIPHER_CTX_iv_length(&ctx));
2087 p += EVP_CIPHER_CTX_iv_length(&ctx);
2088 /* Encrypt session data */
2089 if (!EVP_EncryptUpdate(&ctx, p, &len, session, session_len)) {
2090 goto err;
2091 }
2092 p += len;
2093 if (!EVP_EncryptFinal_ex(&ctx, p, &len)) {
2094 goto err;
2095 }
2096 p += len;
2097
2098 if (!HMAC_Update(&hctx, macstart, p - macstart) ||
2099 !HMAC_Final(&hctx, p, &hlen)) {
2100 goto err;
2101 }
2102
2103 p += hlen;
2104 /* Now write out lengths: p points to end of data written */
2105 /* Total length */
2106 len = p - ssl_handshake_start(ssl);
2107 /* Skip ticket lifetime hint */
2108 p = ssl_handshake_start(ssl) + 4;
2109 s2n(len - 6, p);
2110 if (!ssl_set_handshake_header(ssl, SSL3_MT_NEWSESSION_TICKET, len)) {
2111 goto err;
2112 }
2113 ssl->state = SSL3_ST_SW_SESSION_TICKET_B;
2114 }
2115
2116 /* SSL3_ST_SW_SESSION_TICKET_B */
2117 ret = ssl_do_write(ssl);
2118
2119 err:
2120 OPENSSL_free(session);
2121 EVP_CIPHER_CTX_cleanup(&ctx);
2122 HMAC_CTX_cleanup(&hctx);
2123 return ret;
2124 }
2125
2126 /* ssl3_get_next_proto reads a Next Protocol Negotiation handshake message. It
2127 * sets the next_proto member in s if found */
ssl3_get_next_proto(SSL * ssl)2128 int ssl3_get_next_proto(SSL *ssl) {
2129 int ok;
2130 long n;
2131 CBS next_protocol, selected_protocol, padding;
2132
2133 /* Clients cannot send a NextProtocol message if we didn't see the extension
2134 * in their ClientHello */
2135 if (!ssl->s3->next_proto_neg_seen) {
2136 OPENSSL_PUT_ERROR(SSL, SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION);
2137 return -1;
2138 }
2139
2140 n = ssl->method->ssl_get_message(ssl, SSL3_ST_SR_NEXT_PROTO_A,
2141 SSL3_ST_SR_NEXT_PROTO_B, SSL3_MT_NEXT_PROTO,
2142 514, /* See the payload format below */
2143 ssl_hash_message, &ok);
2144
2145 if (!ok) {
2146 return n;
2147 }
2148
2149 CBS_init(&next_protocol, ssl->init_msg, n);
2150
2151 /* The payload looks like:
2152 * uint8 proto_len;
2153 * uint8 proto[proto_len];
2154 * uint8 padding_len;
2155 * uint8 padding[padding_len]; */
2156 if (!CBS_get_u8_length_prefixed(&next_protocol, &selected_protocol) ||
2157 !CBS_get_u8_length_prefixed(&next_protocol, &padding) ||
2158 CBS_len(&next_protocol) != 0 ||
2159 !CBS_stow(&selected_protocol, &ssl->next_proto_negotiated,
2160 &ssl->next_proto_negotiated_len)) {
2161 return 0;
2162 }
2163
2164 return 1;
2165 }
2166
2167 /* ssl3_get_channel_id reads and verifies a ClientID handshake message. */
ssl3_get_channel_id(SSL * ssl)2168 int ssl3_get_channel_id(SSL *ssl) {
2169 int ret = -1, ok;
2170 long n;
2171 uint8_t channel_id_hash[EVP_MAX_MD_SIZE];
2172 size_t channel_id_hash_len;
2173 const uint8_t *p;
2174 uint16_t extension_type;
2175 EC_GROUP *p256 = NULL;
2176 EC_KEY *key = NULL;
2177 EC_POINT *point = NULL;
2178 ECDSA_SIG sig;
2179 BIGNUM x, y;
2180 CBS encrypted_extensions, extension;
2181
2182 n = ssl->method->ssl_get_message(
2183 ssl, SSL3_ST_SR_CHANNEL_ID_A, SSL3_ST_SR_CHANNEL_ID_B,
2184 SSL3_MT_ENCRYPTED_EXTENSIONS, 2 + 2 + TLSEXT_CHANNEL_ID_SIZE,
2185 ssl_dont_hash_message, &ok);
2186
2187 if (!ok) {
2188 return n;
2189 }
2190
2191 /* Before incorporating the EncryptedExtensions message to the handshake
2192 * hash, compute the hash that should have been signed. */
2193 if (!tls1_channel_id_hash(ssl, channel_id_hash, &channel_id_hash_len)) {
2194 return -1;
2195 }
2196 assert(channel_id_hash_len == SHA256_DIGEST_LENGTH);
2197
2198 if (!ssl3_hash_current_message(ssl)) {
2199 return -1;
2200 }
2201
2202 CBS_init(&encrypted_extensions, ssl->init_msg, n);
2203
2204 /* EncryptedExtensions could include multiple extensions, but the only
2205 * extension that could be negotiated is ChannelID, so there can only be one
2206 * entry.
2207 *
2208 * The payload looks like:
2209 * uint16 extension_type
2210 * uint16 extension_len;
2211 * uint8 x[32];
2212 * uint8 y[32];
2213 * uint8 r[32];
2214 * uint8 s[32]; */
2215
2216 if (!CBS_get_u16(&encrypted_extensions, &extension_type) ||
2217 !CBS_get_u16_length_prefixed(&encrypted_extensions, &extension) ||
2218 CBS_len(&encrypted_extensions) != 0 ||
2219 extension_type != TLSEXT_TYPE_channel_id ||
2220 CBS_len(&extension) != TLSEXT_CHANNEL_ID_SIZE) {
2221 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_MESSAGE);
2222 return -1;
2223 }
2224
2225 p256 = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
2226 if (!p256) {
2227 OPENSSL_PUT_ERROR(SSL, SSL_R_NO_P256_SUPPORT);
2228 return -1;
2229 }
2230
2231 BN_init(&x);
2232 BN_init(&y);
2233 sig.r = BN_new();
2234 sig.s = BN_new();
2235 if (sig.r == NULL || sig.s == NULL) {
2236 goto err;
2237 }
2238
2239 p = CBS_data(&extension);
2240 if (BN_bin2bn(p + 0, 32, &x) == NULL ||
2241 BN_bin2bn(p + 32, 32, &y) == NULL ||
2242 BN_bin2bn(p + 64, 32, sig.r) == NULL ||
2243 BN_bin2bn(p + 96, 32, sig.s) == NULL) {
2244 goto err;
2245 }
2246
2247 point = EC_POINT_new(p256);
2248 if (!point ||
2249 !EC_POINT_set_affine_coordinates_GFp(p256, point, &x, &y, NULL)) {
2250 goto err;
2251 }
2252
2253 key = EC_KEY_new();
2254 if (!key || !EC_KEY_set_group(key, p256) ||
2255 !EC_KEY_set_public_key(key, point)) {
2256 goto err;
2257 }
2258
2259 /* We stored the handshake hash in |tlsext_channel_id| the first time that we
2260 * were called. */
2261 if (!ECDSA_do_verify(channel_id_hash, channel_id_hash_len, &sig, key)) {
2262 OPENSSL_PUT_ERROR(SSL, SSL_R_CHANNEL_ID_SIGNATURE_INVALID);
2263 ssl->s3->tlsext_channel_id_valid = 0;
2264 goto err;
2265 }
2266
2267 memcpy(ssl->s3->tlsext_channel_id, p, 64);
2268 ret = 1;
2269
2270 err:
2271 BN_free(&x);
2272 BN_free(&y);
2273 BN_free(sig.r);
2274 BN_free(sig.s);
2275 EC_KEY_free(key);
2276 EC_POINT_free(point);
2277 EC_GROUP_free(p256);
2278 return ret;
2279 }
2280