1 /*
2 * SSLv3/TLSv1 client-side functions
3 *
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 *
19 * This file is part of mbed TLS (https://tls.mbed.org)
20 */
21
22 #if !defined(MBEDTLS_CONFIG_FILE)
23 #include "mbedtls/config.h"
24 #else
25 #include MBEDTLS_CONFIG_FILE
26 #endif
27
28 #if defined(MBEDTLS_SSL_CLI_C)
29
30 #if defined(MBEDTLS_PLATFORM_C)
31 #include "mbedtls/platform.h"
32 #else
33 #include <stdlib.h>
34 #define mbedtls_calloc calloc
35 #define mbedtls_free free
36 #endif
37
38 #include "mbedtls/debug.h"
39 #include "mbedtls/ssl.h"
40 #include "mbedtls/ssl_internal.h"
41
42 #include <string.h>
43
44 #include <stdint.h>
45
46 #if defined(MBEDTLS_HAVE_TIME)
47 #include "mbedtls/platform_time.h"
48 #endif
49
50 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
51 /* Implementation that should never be optimized out by the compiler */
mbedtls_zeroize(void * v,size_t n)52 static void mbedtls_zeroize( void *v, size_t n ) {
53 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
54 }
55 #endif
56
57 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
ssl_write_hostname_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)58 static void ssl_write_hostname_ext( mbedtls_ssl_context *ssl,
59 unsigned char *buf,
60 size_t *olen )
61 {
62 unsigned char *p = buf;
63 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
64 size_t hostname_len;
65
66 *olen = 0;
67
68 if( ssl->hostname == NULL )
69 return;
70
71 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding server name extension: %s",
72 ssl->hostname ) );
73
74 hostname_len = strlen( ssl->hostname );
75
76 if( end < p || (size_t)( end - p ) < hostname_len + 9 )
77 {
78 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
79 return;
80 }
81
82 /*
83 * struct {
84 * NameType name_type;
85 * select (name_type) {
86 * case host_name: HostName;
87 * } name;
88 * } ServerName;
89 *
90 * enum {
91 * host_name(0), (255)
92 * } NameType;
93 *
94 * opaque HostName<1..2^16-1>;
95 *
96 * struct {
97 * ServerName server_name_list<1..2^16-1>
98 * } ServerNameList;
99 */
100 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME >> 8 ) & 0xFF );
101 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME ) & 0xFF );
102
103 *p++ = (unsigned char)( ( (hostname_len + 5) >> 8 ) & 0xFF );
104 *p++ = (unsigned char)( ( (hostname_len + 5) ) & 0xFF );
105
106 *p++ = (unsigned char)( ( (hostname_len + 3) >> 8 ) & 0xFF );
107 *p++ = (unsigned char)( ( (hostname_len + 3) ) & 0xFF );
108
109 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME ) & 0xFF );
110 *p++ = (unsigned char)( ( hostname_len >> 8 ) & 0xFF );
111 *p++ = (unsigned char)( ( hostname_len ) & 0xFF );
112
113 memcpy( p, ssl->hostname, hostname_len );
114
115 *olen = hostname_len + 9;
116 }
117 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
118
119 #if defined(MBEDTLS_SSL_RENEGOTIATION)
ssl_write_renegotiation_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)120 static void ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl,
121 unsigned char *buf,
122 size_t *olen )
123 {
124 unsigned char *p = buf;
125 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
126
127 *olen = 0;
128
129 if( ssl->renego_status != MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
130 return;
131
132 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding renegotiation extension" ) );
133
134 if( end < p || (size_t)( end - p ) < 5 + ssl->verify_data_len )
135 {
136 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
137 return;
138 }
139
140 /*
141 * Secure renegotiation
142 */
143 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO >> 8 ) & 0xFF );
144 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO ) & 0xFF );
145
146 *p++ = 0x00;
147 *p++ = ( ssl->verify_data_len + 1 ) & 0xFF;
148 *p++ = ssl->verify_data_len & 0xFF;
149
150 memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
151
152 *olen = 5 + ssl->verify_data_len;
153 }
154 #endif /* MBEDTLS_SSL_RENEGOTIATION */
155
156 /*
157 * Only if we handle at least one key exchange that needs signatures.
158 */
159 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
160 defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
ssl_write_signature_algorithms_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)161 static void ssl_write_signature_algorithms_ext( mbedtls_ssl_context *ssl,
162 unsigned char *buf,
163 size_t *olen )
164 {
165 unsigned char *p = buf;
166 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
167 size_t sig_alg_len = 0;
168 const int *md;
169 #if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_C)
170 unsigned char *sig_alg_list = buf + 6;
171 #endif
172
173 *olen = 0;
174
175 if( ssl->conf->max_minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
176 return;
177
178 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding signature_algorithms extension" ) );
179
180 for( md = ssl->conf->sig_hashes; *md != MBEDTLS_MD_NONE; md++ )
181 {
182 #if defined(MBEDTLS_ECDSA_C)
183 sig_alg_len += 2;
184 #endif
185 #if defined(MBEDTLS_RSA_C)
186 sig_alg_len += 2;
187 #endif
188 }
189
190 if( end < p || (size_t)( end - p ) < sig_alg_len + 6 )
191 {
192 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
193 return;
194 }
195
196 /*
197 * Prepare signature_algorithms extension (TLS 1.2)
198 */
199 sig_alg_len = 0;
200
201 for( md = ssl->conf->sig_hashes; *md != MBEDTLS_MD_NONE; md++ )
202 {
203 #if defined(MBEDTLS_ECDSA_C)
204 sig_alg_list[sig_alg_len++] = mbedtls_ssl_hash_from_md_alg( *md );
205 sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
206 #endif
207 #if defined(MBEDTLS_RSA_C)
208 sig_alg_list[sig_alg_len++] = mbedtls_ssl_hash_from_md_alg( *md );
209 sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
210 #endif
211 }
212
213 /*
214 * enum {
215 * none(0), md5(1), sha1(2), sha224(3), sha256(4), sha384(5),
216 * sha512(6), (255)
217 * } HashAlgorithm;
218 *
219 * enum { anonymous(0), rsa(1), dsa(2), ecdsa(3), (255) }
220 * SignatureAlgorithm;
221 *
222 * struct {
223 * HashAlgorithm hash;
224 * SignatureAlgorithm signature;
225 * } SignatureAndHashAlgorithm;
226 *
227 * SignatureAndHashAlgorithm
228 * supported_signature_algorithms<2..2^16-2>;
229 */
230 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SIG_ALG >> 8 ) & 0xFF );
231 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SIG_ALG ) & 0xFF );
232
233 *p++ = (unsigned char)( ( ( sig_alg_len + 2 ) >> 8 ) & 0xFF );
234 *p++ = (unsigned char)( ( ( sig_alg_len + 2 ) ) & 0xFF );
235
236 *p++ = (unsigned char)( ( sig_alg_len >> 8 ) & 0xFF );
237 *p++ = (unsigned char)( ( sig_alg_len ) & 0xFF );
238
239 *olen = 6 + sig_alg_len;
240 }
241 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
242 MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
243
244 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
245 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl_write_supported_elliptic_curves_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)246 static void ssl_write_supported_elliptic_curves_ext( mbedtls_ssl_context *ssl,
247 unsigned char *buf,
248 size_t *olen )
249 {
250 unsigned char *p = buf;
251 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
252 unsigned char *elliptic_curve_list = p + 6;
253 size_t elliptic_curve_len = 0;
254 const mbedtls_ecp_curve_info *info;
255 #if defined(MBEDTLS_ECP_C)
256 const mbedtls_ecp_group_id *grp_id;
257 #else
258 ((void) ssl);
259 #endif
260
261 *olen = 0;
262
263 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_elliptic_curves extension" ) );
264
265 #if defined(MBEDTLS_ECP_C)
266 for( grp_id = ssl->conf->curve_list; *grp_id != MBEDTLS_ECP_DP_NONE; grp_id++ )
267 {
268 info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
269 #else
270 for( info = mbedtls_ecp_curve_list(); info->grp_id != MBEDTLS_ECP_DP_NONE; info++ )
271 {
272 #endif
273 if( info == NULL )
274 {
275 MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid curve in ssl configuration" ) );
276 return;
277 }
278
279 elliptic_curve_len += 2;
280 }
281
282 if( end < p || (size_t)( end - p ) < 6 + elliptic_curve_len )
283 {
284 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
285 return;
286 }
287
288 elliptic_curve_len = 0;
289
290 #if defined(MBEDTLS_ECP_C)
291 for( grp_id = ssl->conf->curve_list; *grp_id != MBEDTLS_ECP_DP_NONE; grp_id++ )
292 {
293 info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
294 #else
295 for( info = mbedtls_ecp_curve_list(); info->grp_id != MBEDTLS_ECP_DP_NONE; info++ )
296 {
297 #endif
298 elliptic_curve_list[elliptic_curve_len++] = info->tls_id >> 8;
299 elliptic_curve_list[elliptic_curve_len++] = info->tls_id & 0xFF;
300 }
301
302 if( elliptic_curve_len == 0 )
303 return;
304
305 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES >> 8 ) & 0xFF );
306 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES ) & 0xFF );
307
308 *p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) >> 8 ) & 0xFF );
309 *p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) ) & 0xFF );
310
311 *p++ = (unsigned char)( ( ( elliptic_curve_len ) >> 8 ) & 0xFF );
312 *p++ = (unsigned char)( ( ( elliptic_curve_len ) ) & 0xFF );
313
314 *olen = 6 + elliptic_curve_len;
315 }
316
317 static void ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl,
318 unsigned char *buf,
319 size_t *olen )
320 {
321 unsigned char *p = buf;
322 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
323
324 *olen = 0;
325
326 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_point_formats extension" ) );
327
328 if( end < p || (size_t)( end - p ) < 6 )
329 {
330 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
331 return;
332 }
333
334 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF );
335 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS ) & 0xFF );
336
337 *p++ = 0x00;
338 *p++ = 2;
339
340 *p++ = 1;
341 *p++ = MBEDTLS_ECP_PF_UNCOMPRESSED;
342
343 *olen = 6;
344 }
345 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
346 MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
347
348 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
349 static void ssl_write_ecjpake_kkpp_ext( mbedtls_ssl_context *ssl,
350 unsigned char *buf,
351 size_t *olen )
352 {
353 int ret;
354 unsigned char *p = buf;
355 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
356 size_t kkpp_len;
357
358 *olen = 0;
359
360 /* Skip costly extension if we can't use EC J-PAKE anyway */
361 if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
362 return;
363
364 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding ecjpake_kkpp extension" ) );
365
366 if( end - p < 4 )
367 {
368 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
369 return;
370 }
371
372 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP >> 8 ) & 0xFF );
373 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP ) & 0xFF );
374
375 /*
376 * We may need to send ClientHello multiple times for Hello verification.
377 * We don't want to compute fresh values every time (both for performance
378 * and consistency reasons), so cache the extension content.
379 */
380 if( ssl->handshake->ecjpake_cache == NULL ||
381 ssl->handshake->ecjpake_cache_len == 0 )
382 {
383 MBEDTLS_SSL_DEBUG_MSG( 3, ( "generating new ecjpake parameters" ) );
384
385 ret = mbedtls_ecjpake_write_round_one( &ssl->handshake->ecjpake_ctx,
386 p + 2, end - p - 2, &kkpp_len,
387 ssl->conf->f_rng, ssl->conf->p_rng );
388 if( ret != 0 )
389 {
390 MBEDTLS_SSL_DEBUG_RET( 1 , "mbedtls_ecjpake_write_round_one", ret );
391 return;
392 }
393
394 ssl->handshake->ecjpake_cache = mbedtls_calloc( 1, kkpp_len );
395 if( ssl->handshake->ecjpake_cache == NULL )
396 {
397 MBEDTLS_SSL_DEBUG_MSG( 1, ( "allocation failed" ) );
398 return;
399 }
400
401 memcpy( ssl->handshake->ecjpake_cache, p + 2, kkpp_len );
402 ssl->handshake->ecjpake_cache_len = kkpp_len;
403 }
404 else
405 {
406 MBEDTLS_SSL_DEBUG_MSG( 3, ( "re-using cached ecjpake parameters" ) );
407
408 kkpp_len = ssl->handshake->ecjpake_cache_len;
409
410 if( (size_t)( end - p - 2 ) < kkpp_len )
411 {
412 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
413 return;
414 }
415
416 memcpy( p + 2, ssl->handshake->ecjpake_cache, kkpp_len );
417 }
418
419 *p++ = (unsigned char)( ( kkpp_len >> 8 ) & 0xFF );
420 *p++ = (unsigned char)( ( kkpp_len ) & 0xFF );
421
422 *olen = kkpp_len + 4;
423 }
424 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
425
426 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
427 static void ssl_write_max_fragment_length_ext( mbedtls_ssl_context *ssl,
428 unsigned char *buf,
429 size_t *olen )
430 {
431 unsigned char *p = buf;
432 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
433
434 *olen = 0;
435
436 if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ) {
437 return;
438 }
439
440 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding max_fragment_length extension" ) );
441
442 if( end < p || (size_t)( end - p ) < 5 )
443 {
444 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
445 return;
446 }
447
448 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH >> 8 ) & 0xFF );
449 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH ) & 0xFF );
450
451 *p++ = 0x00;
452 *p++ = 1;
453
454 *p++ = ssl->conf->mfl_code;
455
456 *olen = 5;
457 }
458 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
459
460 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
461 static void ssl_write_truncated_hmac_ext( mbedtls_ssl_context *ssl,
462 unsigned char *buf, size_t *olen )
463 {
464 unsigned char *p = buf;
465 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
466
467 *olen = 0;
468
469 if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED )
470 {
471 return;
472 }
473
474 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding truncated_hmac extension" ) );
475
476 if( end < p || (size_t)( end - p ) < 4 )
477 {
478 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
479 return;
480 }
481
482 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF );
483 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC ) & 0xFF );
484
485 *p++ = 0x00;
486 *p++ = 0x00;
487
488 *olen = 4;
489 }
490 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
491
492 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
493 static void ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
494 unsigned char *buf, size_t *olen )
495 {
496 unsigned char *p = buf;
497 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
498
499 *olen = 0;
500
501 if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
502 ssl->conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
503 {
504 return;
505 }
506
507 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding encrypt_then_mac "
508 "extension" ) );
509
510 if( end < p || (size_t)( end - p ) < 4 )
511 {
512 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
513 return;
514 }
515
516 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC >> 8 ) & 0xFF );
517 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC ) & 0xFF );
518
519 *p++ = 0x00;
520 *p++ = 0x00;
521
522 *olen = 4;
523 }
524 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
525
526 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
527 static void ssl_write_extended_ms_ext( mbedtls_ssl_context *ssl,
528 unsigned char *buf, size_t *olen )
529 {
530 unsigned char *p = buf;
531 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
532
533 *olen = 0;
534
535 if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
536 ssl->conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
537 {
538 return;
539 }
540
541 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding extended_master_secret "
542 "extension" ) );
543
544 if( end < p || (size_t)( end - p ) < 4 )
545 {
546 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
547 return;
548 }
549
550 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF );
551 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET ) & 0xFF );
552
553 *p++ = 0x00;
554 *p++ = 0x00;
555
556 *olen = 4;
557 }
558 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
559
560 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
561 static void ssl_write_session_ticket_ext( mbedtls_ssl_context *ssl,
562 unsigned char *buf, size_t *olen )
563 {
564 unsigned char *p = buf;
565 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
566 size_t tlen = ssl->session_negotiate->ticket_len;
567
568 *olen = 0;
569
570 if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED )
571 {
572 return;
573 }
574
575 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding session ticket extension" ) );
576
577 if( end < p || (size_t)( end - p ) < 4 + tlen )
578 {
579 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
580 return;
581 }
582
583 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF );
584 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET ) & 0xFF );
585
586 *p++ = (unsigned char)( ( tlen >> 8 ) & 0xFF );
587 *p++ = (unsigned char)( ( tlen ) & 0xFF );
588
589 *olen = 4;
590
591 if( ssl->session_negotiate->ticket == NULL || tlen == 0 )
592 {
593 return;
594 }
595
596 MBEDTLS_SSL_DEBUG_MSG( 3, ( "sending session ticket of length %d", tlen ) );
597
598 memcpy( p, ssl->session_negotiate->ticket, tlen );
599
600 *olen += tlen;
601 }
602 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
603
604 #if defined(MBEDTLS_SSL_ALPN)
605 static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl,
606 unsigned char *buf, size_t *olen )
607 {
608 unsigned char *p = buf;
609 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
610 size_t alpnlen = 0;
611 const char **cur;
612
613 *olen = 0;
614
615 if( ssl->conf->alpn_list == NULL )
616 {
617 return;
618 }
619
620 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding alpn extension" ) );
621
622 for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
623 alpnlen += (unsigned char)( strlen( *cur ) & 0xFF ) + 1;
624
625 if( end < p || (size_t)( end - p ) < 6 + alpnlen )
626 {
627 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
628 return;
629 }
630
631 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN >> 8 ) & 0xFF );
632 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN ) & 0xFF );
633
634 /*
635 * opaque ProtocolName<1..2^8-1>;
636 *
637 * struct {
638 * ProtocolName protocol_name_list<2..2^16-1>
639 * } ProtocolNameList;
640 */
641
642 /* Skip writing extension and list length for now */
643 p += 4;
644
645 for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
646 {
647 *p = (unsigned char)( strlen( *cur ) & 0xFF );
648 memcpy( p + 1, *cur, *p );
649 p += 1 + *p;
650 }
651
652 *olen = p - buf;
653
654 /* List length = olen - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */
655 buf[4] = (unsigned char)( ( ( *olen - 6 ) >> 8 ) & 0xFF );
656 buf[5] = (unsigned char)( ( ( *olen - 6 ) ) & 0xFF );
657
658 /* Extension length = olen - 2 (ext_type) - 2 (ext_len) */
659 buf[2] = (unsigned char)( ( ( *olen - 4 ) >> 8 ) & 0xFF );
660 buf[3] = (unsigned char)( ( ( *olen - 4 ) ) & 0xFF );
661 }
662 #endif /* MBEDTLS_SSL_ALPN */
663
664 /*
665 * Generate random bytes for ClientHello
666 */
667 static int ssl_generate_random( mbedtls_ssl_context *ssl )
668 {
669 int ret;
670 unsigned char *p = ssl->handshake->randbytes;
671 #if defined(MBEDTLS_HAVE_TIME)
672 mbedtls_time_t t;
673 #endif
674
675 /*
676 * When responding to a verify request, MUST reuse random (RFC 6347 4.2.1)
677 */
678 #if defined(MBEDTLS_SSL_PROTO_DTLS)
679 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
680 ssl->handshake->verify_cookie != NULL )
681 {
682 return( 0 );
683 }
684 #endif
685
686 #if defined(MBEDTLS_HAVE_TIME)
687 t = mbedtls_time( NULL );
688 *p++ = (unsigned char)( t >> 24 );
689 *p++ = (unsigned char)( t >> 16 );
690 *p++ = (unsigned char)( t >> 8 );
691 *p++ = (unsigned char)( t );
692
693 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, current time: %lu", t ) );
694 #else
695 if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 4 ) ) != 0 )
696 return( ret );
697
698 p += 4;
699 #endif /* MBEDTLS_HAVE_TIME */
700
701 if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 28 ) ) != 0 )
702 return( ret );
703
704 return( 0 );
705 }
706
707 static int ssl_write_client_hello( mbedtls_ssl_context *ssl )
708 {
709 int ret;
710 size_t i, n, olen, ext_len = 0;
711 unsigned char *buf;
712 unsigned char *p, *q;
713 unsigned char offer_compress;
714 const int *ciphersuites;
715 const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
716
717 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write client hello" ) );
718
719 if( ssl->conf->f_rng == NULL )
720 {
721 MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided") );
722 return( MBEDTLS_ERR_SSL_NO_RNG );
723 }
724
725 #if defined(MBEDTLS_SSL_RENEGOTIATION)
726 if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
727 #endif
728 {
729 ssl->major_ver = ssl->conf->min_major_ver;
730 ssl->minor_ver = ssl->conf->min_minor_ver;
731 }
732
733 if( ssl->conf->max_major_ver == 0 )
734 {
735 MBEDTLS_SSL_DEBUG_MSG( 1, ( "configured max major version is invalid, "
736 "consider using mbedtls_ssl_config_defaults()" ) );
737 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
738 }
739
740 /*
741 * 0 . 0 handshake type
742 * 1 . 3 handshake length
743 * 4 . 5 highest version supported
744 * 6 . 9 current UNIX time
745 * 10 . 37 random bytes
746 */
747 buf = ssl->out_msg;
748 p = buf + 4;
749
750 mbedtls_ssl_write_version( ssl->conf->max_major_ver, ssl->conf->max_minor_ver,
751 ssl->conf->transport, p );
752 p += 2;
753
754 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, max version: [%d:%d]",
755 buf[4], buf[5] ) );
756
757 if( ( ret = ssl_generate_random( ssl ) ) != 0 )
758 {
759 MBEDTLS_SSL_DEBUG_RET( 1, "ssl_generate_random", ret );
760 return( ret );
761 }
762
763 memcpy( p, ssl->handshake->randbytes, 32 );
764 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", p, 32 );
765 p += 32;
766
767 /*
768 * 38 . 38 session id length
769 * 39 . 39+n session id
770 * 39+n . 39+n DTLS only: cookie length (1 byte)
771 * 40+n . .. DTSL only: cookie
772 * .. . .. ciphersuitelist length (2 bytes)
773 * .. . .. ciphersuitelist
774 * .. . .. compression methods length (1 byte)
775 * .. . .. compression methods
776 * .. . .. extensions length (2 bytes)
777 * .. . .. extensions
778 */
779 n = ssl->session_negotiate->id_len;
780
781 if( n < 16 || n > 32 ||
782 #if defined(MBEDTLS_SSL_RENEGOTIATION)
783 ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
784 #endif
785 ssl->handshake->resume == 0 )
786 {
787 n = 0;
788 }
789
790 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
791 /*
792 * RFC 5077 section 3.4: "When presenting a ticket, the client MAY
793 * generate and include a Session ID in the TLS ClientHello."
794 */
795 #if defined(MBEDTLS_SSL_RENEGOTIATION)
796 if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
797 #endif
798 {
799 if( ssl->session_negotiate->ticket != NULL &&
800 ssl->session_negotiate->ticket_len != 0 )
801 {
802 ret = ssl->conf->f_rng( ssl->conf->p_rng, ssl->session_negotiate->id, 32 );
803
804 if( ret != 0 )
805 return( ret );
806
807 ssl->session_negotiate->id_len = n = 32;
808 }
809 }
810 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
811
812 *p++ = (unsigned char) n;
813
814 for( i = 0; i < n; i++ )
815 *p++ = ssl->session_negotiate->id[i];
816
817 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, session id len.: %d", n ) );
818 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 39, n );
819
820 /*
821 * DTLS cookie
822 */
823 #if defined(MBEDTLS_SSL_PROTO_DTLS)
824 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
825 {
826 if( ssl->handshake->verify_cookie == NULL )
827 {
828 MBEDTLS_SSL_DEBUG_MSG( 3, ( "no verify cookie to send" ) );
829 *p++ = 0;
830 }
831 else
832 {
833 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie",
834 ssl->handshake->verify_cookie,
835 ssl->handshake->verify_cookie_len );
836
837 *p++ = ssl->handshake->verify_cookie_len;
838 memcpy( p, ssl->handshake->verify_cookie,
839 ssl->handshake->verify_cookie_len );
840 p += ssl->handshake->verify_cookie_len;
841 }
842 }
843 #endif
844
845 /*
846 * Ciphersuite list
847 */
848 ciphersuites = ssl->conf->ciphersuite_list[ssl->minor_ver];
849
850 /* Skip writing ciphersuite length for now */
851 n = 0;
852 q = p;
853 p += 2;
854
855 for( i = 0; ciphersuites[i] != 0; i++ )
856 {
857 ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( ciphersuites[i] );
858
859 if( ciphersuite_info == NULL )
860 continue;
861
862 if( ciphersuite_info->min_minor_ver > ssl->conf->max_minor_ver ||
863 ciphersuite_info->max_minor_ver < ssl->conf->min_minor_ver )
864 continue;
865
866 #if defined(MBEDTLS_SSL_PROTO_DTLS)
867 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
868 ( ciphersuite_info->flags & MBEDTLS_CIPHERSUITE_NODTLS ) )
869 continue;
870 #endif
871
872 #if defined(MBEDTLS_ARC4_C)
873 if( ssl->conf->arc4_disabled == MBEDTLS_SSL_ARC4_DISABLED &&
874 ciphersuite_info->cipher == MBEDTLS_CIPHER_ARC4_128 )
875 continue;
876 #endif
877
878 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
879 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE &&
880 mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
881 continue;
882 #endif
883
884 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %04x",
885 ciphersuites[i] ) );
886
887 n++;
888 *p++ = (unsigned char)( ciphersuites[i] >> 8 );
889 *p++ = (unsigned char)( ciphersuites[i] );
890 }
891
892 /*
893 * Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV
894 */
895 #if defined(MBEDTLS_SSL_RENEGOTIATION)
896 if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
897 #endif
898 {
899 *p++ = (unsigned char)( MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO >> 8 );
900 *p++ = (unsigned char)( MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO );
901 n++;
902 }
903
904 /* Some versions of OpenSSL don't handle it correctly if not at end */
905 #if defined(MBEDTLS_SSL_FALLBACK_SCSV)
906 if( ssl->conf->fallback == MBEDTLS_SSL_IS_FALLBACK )
907 {
908 MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding FALLBACK_SCSV" ) );
909 *p++ = (unsigned char)( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 );
910 *p++ = (unsigned char)( MBEDTLS_SSL_FALLBACK_SCSV_VALUE );
911 n++;
912 }
913 #endif
914
915 *q++ = (unsigned char)( n >> 7 );
916 *q++ = (unsigned char)( n << 1 );
917
918 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, got %d ciphersuites", n ) );
919
920 #if defined(MBEDTLS_ZLIB_SUPPORT)
921 offer_compress = 1;
922 #else
923 offer_compress = 0;
924 #endif
925
926 /*
927 * We don't support compression with DTLS right now: is many records come
928 * in the same datagram, uncompressing one could overwrite the next one.
929 * We don't want to add complexity for handling that case unless there is
930 * an actual need for it.
931 */
932 #if defined(MBEDTLS_SSL_PROTO_DTLS)
933 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
934 offer_compress = 0;
935 #endif
936
937 if( offer_compress )
938 {
939 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 2 ) );
940 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d %d",
941 MBEDTLS_SSL_COMPRESS_DEFLATE, MBEDTLS_SSL_COMPRESS_NULL ) );
942
943 *p++ = 2;
944 *p++ = MBEDTLS_SSL_COMPRESS_DEFLATE;
945 *p++ = MBEDTLS_SSL_COMPRESS_NULL;
946 }
947 else
948 {
949 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 1 ) );
950 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d",
951 MBEDTLS_SSL_COMPRESS_NULL ) );
952
953 *p++ = 1;
954 *p++ = MBEDTLS_SSL_COMPRESS_NULL;
955 }
956
957 // First write extensions, then the total length
958 //
959 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
960 ssl_write_hostname_ext( ssl, p + 2 + ext_len, &olen );
961 ext_len += olen;
962 #endif
963
964 #if defined(MBEDTLS_SSL_RENEGOTIATION)
965 ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen );
966 ext_len += olen;
967 #endif
968
969 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
970 defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
971 ssl_write_signature_algorithms_ext( ssl, p + 2 + ext_len, &olen );
972 ext_len += olen;
973 #endif
974
975 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
976 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
977 ssl_write_supported_elliptic_curves_ext( ssl, p + 2 + ext_len, &olen );
978 ext_len += olen;
979
980 ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
981 ext_len += olen;
982 #endif
983
984 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
985 ssl_write_ecjpake_kkpp_ext( ssl, p + 2 + ext_len, &olen );
986 ext_len += olen;
987 #endif
988
989 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
990 ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen );
991 ext_len += olen;
992 #endif
993
994 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
995 ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen );
996 ext_len += olen;
997 #endif
998
999 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
1000 ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len, &olen );
1001 ext_len += olen;
1002 #endif
1003
1004 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
1005 ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen );
1006 ext_len += olen;
1007 #endif
1008
1009 #if defined(MBEDTLS_SSL_ALPN)
1010 ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen );
1011 ext_len += olen;
1012 #endif
1013
1014 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
1015 ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
1016 ext_len += olen;
1017 #endif
1018
1019 /* olen unused if all extensions are disabled */
1020 ((void) olen);
1021
1022 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d",
1023 ext_len ) );
1024
1025 if( ext_len > 0 )
1026 {
1027 *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF );
1028 *p++ = (unsigned char)( ( ext_len ) & 0xFF );
1029 p += ext_len;
1030 }
1031
1032 ssl->out_msglen = p - buf;
1033 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
1034 ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_HELLO;
1035
1036 ssl->state++;
1037
1038 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1039 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1040 mbedtls_ssl_send_flight_completed( ssl );
1041 #endif
1042
1043 if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 )
1044 {
1045 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
1046 return( ret );
1047 }
1048
1049 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write client hello" ) );
1050
1051 return( 0 );
1052 }
1053
1054 static int ssl_parse_renegotiation_info( mbedtls_ssl_context *ssl,
1055 const unsigned char *buf,
1056 size_t len )
1057 {
1058 int ret;
1059
1060 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1061 if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
1062 {
1063 /* Check verify-data in constant-time. The length OTOH is no secret */
1064 if( len != 1 + ssl->verify_data_len * 2 ||
1065 buf[0] != ssl->verify_data_len * 2 ||
1066 mbedtls_ssl_safer_memcmp( buf + 1,
1067 ssl->own_verify_data, ssl->verify_data_len ) != 0 ||
1068 mbedtls_ssl_safer_memcmp( buf + 1 + ssl->verify_data_len,
1069 ssl->peer_verify_data, ssl->verify_data_len ) != 0 )
1070 {
1071 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
1072
1073 if( ( ret = mbedtls_ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
1074 return( ret );
1075
1076 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1077 }
1078 }
1079 else
1080 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1081 {
1082 if( len != 1 || buf[0] != 0x00 )
1083 {
1084 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
1085
1086 if( ( ret = mbedtls_ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
1087 return( ret );
1088
1089 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1090 }
1091
1092 ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
1093 }
1094
1095 return( 0 );
1096 }
1097
1098 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
1099 static int ssl_parse_max_fragment_length_ext( mbedtls_ssl_context *ssl,
1100 const unsigned char *buf,
1101 size_t len )
1102 {
1103 /*
1104 * server should use the extension only if we did,
1105 * and if so the server's value should match ours (and len is always 1)
1106 */
1107 if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ||
1108 len != 1 ||
1109 buf[0] != ssl->conf->mfl_code )
1110 {
1111 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1112 }
1113
1114 return( 0 );
1115 }
1116 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
1117
1118 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
1119 static int ssl_parse_truncated_hmac_ext( mbedtls_ssl_context *ssl,
1120 const unsigned char *buf,
1121 size_t len )
1122 {
1123 if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED ||
1124 len != 0 )
1125 {
1126 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1127 }
1128
1129 ((void) buf);
1130
1131 ssl->session_negotiate->trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_ENABLED;
1132
1133 return( 0 );
1134 }
1135 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
1136
1137 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
1138 static int ssl_parse_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
1139 const unsigned char *buf,
1140 size_t len )
1141 {
1142 if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
1143 ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ||
1144 len != 0 )
1145 {
1146 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1147 }
1148
1149 ((void) buf);
1150
1151 ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED;
1152
1153 return( 0 );
1154 }
1155 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
1156
1157 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
1158 static int ssl_parse_extended_ms_ext( mbedtls_ssl_context *ssl,
1159 const unsigned char *buf,
1160 size_t len )
1161 {
1162 if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
1163 ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ||
1164 len != 0 )
1165 {
1166 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1167 }
1168
1169 ((void) buf);
1170
1171 ssl->handshake->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED;
1172
1173 return( 0 );
1174 }
1175 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
1176
1177 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
1178 static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
1179 const unsigned char *buf,
1180 size_t len )
1181 {
1182 if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED ||
1183 len != 0 )
1184 {
1185 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1186 }
1187
1188 ((void) buf);
1189
1190 ssl->handshake->new_session_ticket = 1;
1191
1192 return( 0 );
1193 }
1194 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
1195
1196 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
1197 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1198 static int ssl_parse_supported_point_formats_ext( mbedtls_ssl_context *ssl,
1199 const unsigned char *buf,
1200 size_t len )
1201 {
1202 size_t list_size;
1203 const unsigned char *p;
1204
1205 list_size = buf[0];
1206 if( list_size + 1 != len )
1207 {
1208 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1209 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1210 }
1211
1212 p = buf + 1;
1213 while( list_size > 0 )
1214 {
1215 if( p[0] == MBEDTLS_ECP_PF_UNCOMPRESSED ||
1216 p[0] == MBEDTLS_ECP_PF_COMPRESSED )
1217 {
1218 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
1219 ssl->handshake->ecdh_ctx.point_format = p[0];
1220 #endif
1221 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1222 ssl->handshake->ecjpake_ctx.point_format = p[0];
1223 #endif
1224 MBEDTLS_SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) );
1225 return( 0 );
1226 }
1227
1228 list_size--;
1229 p++;
1230 }
1231
1232 MBEDTLS_SSL_DEBUG_MSG( 1, ( "no point format in common" ) );
1233 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1234 }
1235 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
1236 MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1237
1238 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1239 static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl,
1240 const unsigned char *buf,
1241 size_t len )
1242 {
1243 int ret;
1244
1245 if( ssl->transform_negotiate->ciphersuite_info->key_exchange !=
1246 MBEDTLS_KEY_EXCHANGE_ECJPAKE )
1247 {
1248 MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip ecjpake kkpp extension" ) );
1249 return( 0 );
1250 }
1251
1252 /* If we got here, we no longer need our cached extension */
1253 mbedtls_free( ssl->handshake->ecjpake_cache );
1254 ssl->handshake->ecjpake_cache = NULL;
1255 ssl->handshake->ecjpake_cache_len = 0;
1256
1257 if( ( ret = mbedtls_ecjpake_read_round_one( &ssl->handshake->ecjpake_ctx,
1258 buf, len ) ) != 0 )
1259 {
1260 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_one", ret );
1261 return( ret );
1262 }
1263
1264 return( 0 );
1265 }
1266 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1267
1268 #if defined(MBEDTLS_SSL_ALPN)
1269 static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl,
1270 const unsigned char *buf, size_t len )
1271 {
1272 size_t list_len, name_len;
1273 const char **p;
1274
1275 /* If we didn't send it, the server shouldn't send it */
1276 if( ssl->conf->alpn_list == NULL )
1277 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1278
1279 /*
1280 * opaque ProtocolName<1..2^8-1>;
1281 *
1282 * struct {
1283 * ProtocolName protocol_name_list<2..2^16-1>
1284 * } ProtocolNameList;
1285 *
1286 * the "ProtocolNameList" MUST contain exactly one "ProtocolName"
1287 */
1288
1289 /* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */
1290 if( len < 4 )
1291 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1292
1293 list_len = ( buf[0] << 8 ) | buf[1];
1294 if( list_len != len - 2 )
1295 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1296
1297 name_len = buf[2];
1298 if( name_len != list_len - 1 )
1299 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1300
1301 /* Check that the server chosen protocol was in our list and save it */
1302 for( p = ssl->conf->alpn_list; *p != NULL; p++ )
1303 {
1304 if( name_len == strlen( *p ) &&
1305 memcmp( buf + 3, *p, name_len ) == 0 )
1306 {
1307 ssl->alpn_chosen = *p;
1308 return( 0 );
1309 }
1310 }
1311
1312 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1313 }
1314 #endif /* MBEDTLS_SSL_ALPN */
1315
1316 /*
1317 * Parse HelloVerifyRequest. Only called after verifying the HS type.
1318 */
1319 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1320 static int ssl_parse_hello_verify_request( mbedtls_ssl_context *ssl )
1321 {
1322 const unsigned char *p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
1323 int major_ver, minor_ver;
1324 unsigned char cookie_len;
1325
1326 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse hello verify request" ) );
1327
1328 /*
1329 * struct {
1330 * ProtocolVersion server_version;
1331 * opaque cookie<0..2^8-1>;
1332 * } HelloVerifyRequest;
1333 */
1334 MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
1335 mbedtls_ssl_read_version( &major_ver, &minor_ver, ssl->conf->transport, p );
1336 p += 2;
1337
1338 /*
1339 * Since the RFC is not clear on this point, accept DTLS 1.0 (TLS 1.1)
1340 * even is lower than our min version.
1341 */
1342 if( major_ver < MBEDTLS_SSL_MAJOR_VERSION_3 ||
1343 minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 ||
1344 major_ver > ssl->conf->max_major_ver ||
1345 minor_ver > ssl->conf->max_minor_ver )
1346 {
1347 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server version" ) );
1348
1349 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1350 MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
1351
1352 return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
1353 }
1354
1355 cookie_len = *p++;
1356 MBEDTLS_SSL_DEBUG_BUF( 3, "cookie", p, cookie_len );
1357
1358 if( ( ssl->in_msg + ssl->in_msglen ) - p < cookie_len )
1359 {
1360 MBEDTLS_SSL_DEBUG_MSG( 1,
1361 ( "cookie length does not match incoming message size" ) );
1362 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1363 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1364 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1365 }
1366
1367 mbedtls_free( ssl->handshake->verify_cookie );
1368
1369 ssl->handshake->verify_cookie = mbedtls_calloc( 1, cookie_len );
1370 if( ssl->handshake->verify_cookie == NULL )
1371 {
1372 MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc failed (%d bytes)", cookie_len ) );
1373 return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
1374 }
1375
1376 memcpy( ssl->handshake->verify_cookie, p, cookie_len );
1377 ssl->handshake->verify_cookie_len = cookie_len;
1378
1379 /* Start over at ClientHello */
1380 ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
1381 mbedtls_ssl_reset_checksum( ssl );
1382
1383 mbedtls_ssl_recv_flight_completed( ssl );
1384
1385 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse hello verify request" ) );
1386
1387 return( 0 );
1388 }
1389 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1390
1391 static int ssl_parse_server_hello( mbedtls_ssl_context *ssl )
1392 {
1393 int ret, i;
1394 size_t n;
1395 size_t ext_len;
1396 unsigned char *buf, *ext;
1397 unsigned char comp;
1398 #if defined(MBEDTLS_ZLIB_SUPPORT)
1399 int accept_comp;
1400 #endif
1401 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1402 int renegotiation_info_seen = 0;
1403 #endif
1404 int handshake_failure = 0;
1405 const mbedtls_ssl_ciphersuite_t *suite_info;
1406 #if defined(MBEDTLS_DEBUG_C)
1407 uint32_t t;
1408 #endif
1409
1410 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello" ) );
1411
1412 buf = ssl->in_msg;
1413
1414 if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
1415 {
1416 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
1417 return( ret );
1418 }
1419
1420 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
1421 {
1422 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1423 if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
1424 {
1425 ssl->renego_records_seen++;
1426
1427 if( ssl->conf->renego_max_records >= 0 &&
1428 ssl->renego_records_seen > ssl->conf->renego_max_records )
1429 {
1430 MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation requested, "
1431 "but not honored by server" ) );
1432 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
1433 }
1434
1435 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-handshake message during renego" ) );
1436 return( MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO );
1437 }
1438 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1439
1440 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1441 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
1442 }
1443
1444 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1445 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1446 {
1447 if( buf[0] == MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST )
1448 {
1449 MBEDTLS_SSL_DEBUG_MSG( 2, ( "received hello verify request" ) );
1450 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
1451 return( ssl_parse_hello_verify_request( ssl ) );
1452 }
1453 else
1454 {
1455 /* We made it through the verification process */
1456 mbedtls_free( ssl->handshake->verify_cookie );
1457 ssl->handshake->verify_cookie = NULL;
1458 ssl->handshake->verify_cookie_len = 0;
1459 }
1460 }
1461 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1462
1463 if( ssl->in_hslen < 38 + mbedtls_ssl_hs_hdr_len( ssl ) ||
1464 buf[0] != MBEDTLS_SSL_HS_SERVER_HELLO )
1465 {
1466 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1467 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1468 }
1469
1470 /*
1471 * 0 . 1 server_version
1472 * 2 . 33 random (maybe including 4 bytes of Unix time)
1473 * 34 . 34 session_id length = n
1474 * 35 . 34+n session_id
1475 * 35+n . 36+n cipher_suite
1476 * 37+n . 37+n compression_method
1477 *
1478 * 38+n . 39+n extensions length (optional)
1479 * 40+n . .. extensions
1480 */
1481 buf += mbedtls_ssl_hs_hdr_len( ssl );
1482
1483 MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, version", buf + 0, 2 );
1484 mbedtls_ssl_read_version( &ssl->major_ver, &ssl->minor_ver,
1485 ssl->conf->transport, buf + 0 );
1486
1487 if( ssl->major_ver < ssl->conf->min_major_ver ||
1488 ssl->minor_ver < ssl->conf->min_minor_ver ||
1489 ssl->major_ver > ssl->conf->max_major_ver ||
1490 ssl->minor_ver > ssl->conf->max_minor_ver )
1491 {
1492 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server version out of bounds - "
1493 " min: [%d:%d], server: [%d:%d], max: [%d:%d]",
1494 ssl->conf->min_major_ver, ssl->conf->min_minor_ver,
1495 ssl->major_ver, ssl->minor_ver,
1496 ssl->conf->max_major_ver, ssl->conf->max_minor_ver ) );
1497
1498 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1499 MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
1500
1501 return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
1502 }
1503
1504 #if defined(MBEDTLS_DEBUG_C)
1505 t = ( (uint32_t) buf[2] << 24 )
1506 | ( (uint32_t) buf[3] << 16 )
1507 | ( (uint32_t) buf[4] << 8 )
1508 | ( (uint32_t) buf[5] );
1509 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", t ) );
1510 #endif
1511
1512 memcpy( ssl->handshake->randbytes + 32, buf + 2, 32 );
1513
1514 n = buf[34];
1515
1516 MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 2, 32 );
1517
1518 if( n > 32 )
1519 {
1520 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1521 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1522 }
1523
1524 if( ssl->in_hslen > mbedtls_ssl_hs_hdr_len( ssl ) + 39 + n )
1525 {
1526 ext_len = ( ( buf[38 + n] << 8 )
1527 | ( buf[39 + n] ) );
1528
1529 if( ( ext_len > 0 && ext_len < 4 ) ||
1530 ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + 40 + n + ext_len )
1531 {
1532 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1533 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1534 }
1535 }
1536 else if( ssl->in_hslen == mbedtls_ssl_hs_hdr_len( ssl ) + 38 + n )
1537 {
1538 ext_len = 0;
1539 }
1540 else
1541 {
1542 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1543 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1544 }
1545
1546 /* ciphersuite (used later) */
1547 i = ( buf[35 + n] << 8 ) | buf[36 + n];
1548
1549 /*
1550 * Read and check compression
1551 */
1552 comp = buf[37 + n];
1553
1554 #if defined(MBEDTLS_ZLIB_SUPPORT)
1555 /* See comments in ssl_write_client_hello() */
1556 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1557 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1558 accept_comp = 0;
1559 else
1560 #endif
1561 accept_comp = 1;
1562
1563 if( comp != MBEDTLS_SSL_COMPRESS_NULL &&
1564 ( comp != MBEDTLS_SSL_COMPRESS_DEFLATE || accept_comp == 0 ) )
1565 #else /* MBEDTLS_ZLIB_SUPPORT */
1566 if( comp != MBEDTLS_SSL_COMPRESS_NULL )
1567 #endif/* MBEDTLS_ZLIB_SUPPORT */
1568 {
1569 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server hello, bad compression: %d", comp ) );
1570 return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
1571 }
1572
1573 /*
1574 * Initialize update checksum functions
1575 */
1576 ssl->transform_negotiate->ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( i );
1577
1578 if( ssl->transform_negotiate->ciphersuite_info == NULL )
1579 {
1580 MBEDTLS_SSL_DEBUG_MSG( 1, ( "ciphersuite info for %04x not found", i ) );
1581 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
1582 }
1583
1584 mbedtls_ssl_optimize_checksum( ssl, ssl->transform_negotiate->ciphersuite_info );
1585
1586 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
1587 MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, session id", buf + 35, n );
1588
1589 /*
1590 * Check if the session can be resumed
1591 */
1592 if( ssl->handshake->resume == 0 || n == 0 ||
1593 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1594 ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
1595 #endif
1596 ssl->session_negotiate->ciphersuite != i ||
1597 ssl->session_negotiate->compression != comp ||
1598 ssl->session_negotiate->id_len != n ||
1599 memcmp( ssl->session_negotiate->id, buf + 35, n ) != 0 )
1600 {
1601 ssl->state++;
1602 ssl->handshake->resume = 0;
1603 #if defined(MBEDTLS_HAVE_TIME)
1604 ssl->session_negotiate->start = mbedtls_time( NULL );
1605 #endif
1606 ssl->session_negotiate->ciphersuite = i;
1607 ssl->session_negotiate->compression = comp;
1608 ssl->session_negotiate->id_len = n;
1609 memcpy( ssl->session_negotiate->id, buf + 35, n );
1610 }
1611 else
1612 {
1613 ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
1614
1615 if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
1616 {
1617 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
1618 return( ret );
1619 }
1620 }
1621
1622 MBEDTLS_SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
1623 ssl->handshake->resume ? "a" : "no" ) );
1624
1625 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %04x", i ) );
1626 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", buf[37 + n] ) );
1627
1628 suite_info = mbedtls_ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite );
1629 if( suite_info == NULL
1630 #if defined(MBEDTLS_ARC4_C)
1631 || ( ssl->conf->arc4_disabled &&
1632 suite_info->cipher == MBEDTLS_CIPHER_ARC4_128 )
1633 #endif
1634 )
1635 {
1636 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1637 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1638 }
1639
1640 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %s", suite_info->name ) );
1641
1642 i = 0;
1643 while( 1 )
1644 {
1645 if( ssl->conf->ciphersuite_list[ssl->minor_ver][i] == 0 )
1646 {
1647 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1648 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1649 }
1650
1651 if( ssl->conf->ciphersuite_list[ssl->minor_ver][i++] ==
1652 ssl->session_negotiate->ciphersuite )
1653 {
1654 break;
1655 }
1656 }
1657
1658 if( comp != MBEDTLS_SSL_COMPRESS_NULL
1659 #if defined(MBEDTLS_ZLIB_SUPPORT)
1660 && comp != MBEDTLS_SSL_COMPRESS_DEFLATE
1661 #endif
1662 )
1663 {
1664 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1665 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1666 }
1667 ssl->session_negotiate->compression = comp;
1668
1669 ext = buf + 40 + n;
1670
1671 MBEDTLS_SSL_DEBUG_MSG( 2, ( "server hello, total extension length: %d", ext_len ) );
1672
1673 while( ext_len )
1674 {
1675 unsigned int ext_id = ( ( ext[0] << 8 )
1676 | ( ext[1] ) );
1677 unsigned int ext_size = ( ( ext[2] << 8 )
1678 | ( ext[3] ) );
1679
1680 if( ext_size + 4 > ext_len )
1681 {
1682 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1683 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1684 }
1685
1686 switch( ext_id )
1687 {
1688 case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO:
1689 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
1690 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1691 renegotiation_info_seen = 1;
1692 #endif
1693
1694 if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4,
1695 ext_size ) ) != 0 )
1696 return( ret );
1697
1698 break;
1699
1700 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
1701 case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH:
1702 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found max_fragment_length extension" ) );
1703
1704 if( ( ret = ssl_parse_max_fragment_length_ext( ssl,
1705 ext + 4, ext_size ) ) != 0 )
1706 {
1707 return( ret );
1708 }
1709
1710 break;
1711 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
1712
1713 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
1714 case MBEDTLS_TLS_EXT_TRUNCATED_HMAC:
1715 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found truncated_hmac extension" ) );
1716
1717 if( ( ret = ssl_parse_truncated_hmac_ext( ssl,
1718 ext + 4, ext_size ) ) != 0 )
1719 {
1720 return( ret );
1721 }
1722
1723 break;
1724 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
1725
1726 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
1727 case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
1728 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt_then_mac extension" ) );
1729
1730 if( ( ret = ssl_parse_encrypt_then_mac_ext( ssl,
1731 ext + 4, ext_size ) ) != 0 )
1732 {
1733 return( ret );
1734 }
1735
1736 break;
1737 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
1738
1739 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
1740 case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET:
1741 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extended_master_secret extension" ) );
1742
1743 if( ( ret = ssl_parse_extended_ms_ext( ssl,
1744 ext + 4, ext_size ) ) != 0 )
1745 {
1746 return( ret );
1747 }
1748
1749 break;
1750 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
1751
1752 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
1753 case MBEDTLS_TLS_EXT_SESSION_TICKET:
1754 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found session_ticket extension" ) );
1755
1756 if( ( ret = ssl_parse_session_ticket_ext( ssl,
1757 ext + 4, ext_size ) ) != 0 )
1758 {
1759 return( ret );
1760 }
1761
1762 break;
1763 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
1764
1765 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
1766 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1767 case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS:
1768 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported_point_formats extension" ) );
1769
1770 if( ( ret = ssl_parse_supported_point_formats_ext( ssl,
1771 ext + 4, ext_size ) ) != 0 )
1772 {
1773 return( ret );
1774 }
1775
1776 break;
1777 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
1778 MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1779
1780 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1781 case MBEDTLS_TLS_EXT_ECJPAKE_KKPP:
1782 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ecjpake_kkpp extension" ) );
1783
1784 if( ( ret = ssl_parse_ecjpake_kkpp( ssl,
1785 ext + 4, ext_size ) ) != 0 )
1786 {
1787 return( ret );
1788 }
1789
1790 break;
1791 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1792
1793 #if defined(MBEDTLS_SSL_ALPN)
1794 case MBEDTLS_TLS_EXT_ALPN:
1795 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
1796
1797 if( ( ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size ) ) != 0 )
1798 return( ret );
1799
1800 break;
1801 #endif /* MBEDTLS_SSL_ALPN */
1802
1803 default:
1804 MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)",
1805 ext_id ) );
1806 }
1807
1808 ext_len -= 4 + ext_size;
1809 ext += 4 + ext_size;
1810
1811 if( ext_len > 0 && ext_len < 4 )
1812 {
1813 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1814 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1815 }
1816 }
1817
1818 /*
1819 * Renegotiation security checks
1820 */
1821 if( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
1822 ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE )
1823 {
1824 MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
1825 handshake_failure = 1;
1826 }
1827 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1828 else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
1829 ssl->secure_renegotiation == MBEDTLS_SSL_SECURE_RENEGOTIATION &&
1830 renegotiation_info_seen == 0 )
1831 {
1832 MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) );
1833 handshake_failure = 1;
1834 }
1835 else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
1836 ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
1837 ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION )
1838 {
1839 MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) );
1840 handshake_failure = 1;
1841 }
1842 else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
1843 ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
1844 renegotiation_info_seen == 1 )
1845 {
1846 MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
1847 handshake_failure = 1;
1848 }
1849 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1850
1851 if( handshake_failure == 1 )
1852 {
1853 if( ( ret = mbedtls_ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
1854 return( ret );
1855
1856 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1857 }
1858
1859 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
1860
1861 return( 0 );
1862 }
1863
1864 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
1865 defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
1866 static int ssl_parse_server_dh_params( mbedtls_ssl_context *ssl, unsigned char **p,
1867 unsigned char *end )
1868 {
1869 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
1870
1871 /*
1872 * Ephemeral DH parameters:
1873 *
1874 * struct {
1875 * opaque dh_p<1..2^16-1>;
1876 * opaque dh_g<1..2^16-1>;
1877 * opaque dh_Ys<1..2^16-1>;
1878 * } ServerDHParams;
1879 */
1880 if( ( ret = mbedtls_dhm_read_params( &ssl->handshake->dhm_ctx, p, end ) ) != 0 )
1881 {
1882 MBEDTLS_SSL_DEBUG_RET( 2, ( "mbedtls_dhm_read_params" ), ret );
1883 return( ret );
1884 }
1885
1886 if( ssl->handshake->dhm_ctx.len * 8 < ssl->conf->dhm_min_bitlen )
1887 {
1888 MBEDTLS_SSL_DEBUG_MSG( 1, ( "DHM prime too short: %d < %d",
1889 ssl->handshake->dhm_ctx.len * 8,
1890 ssl->conf->dhm_min_bitlen ) );
1891 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
1892 }
1893
1894 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P );
1895 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G );
1896 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
1897
1898 return( ret );
1899 }
1900 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
1901 MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
1902
1903 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
1904 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
1905 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
1906 defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
1907 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
1908 static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl )
1909 {
1910 const mbedtls_ecp_curve_info *curve_info;
1911
1912 curve_info = mbedtls_ecp_curve_info_from_grp_id( ssl->handshake->ecdh_ctx.grp.id );
1913 if( curve_info == NULL )
1914 {
1915 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
1916 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
1917 }
1918
1919 MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) );
1920
1921 #if defined(MBEDTLS_ECP_C)
1922 if( mbedtls_ssl_check_curve( ssl, ssl->handshake->ecdh_ctx.grp.id ) != 0 )
1923 #else
1924 if( ssl->handshake->ecdh_ctx.grp.nbits < 163 ||
1925 ssl->handshake->ecdh_ctx.grp.nbits > 521 )
1926 #endif
1927 return( -1 );
1928
1929 MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Qp", &ssl->handshake->ecdh_ctx.Qp );
1930
1931 return( 0 );
1932 }
1933 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
1934 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
1935 MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
1936 MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
1937 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
1938
1939 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
1940 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
1941 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
1942 static int ssl_parse_server_ecdh_params( mbedtls_ssl_context *ssl,
1943 unsigned char **p,
1944 unsigned char *end )
1945 {
1946 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
1947
1948 /*
1949 * Ephemeral ECDH parameters:
1950 *
1951 * struct {
1952 * ECParameters curve_params;
1953 * ECPoint public;
1954 * } ServerECDHParams;
1955 */
1956 if( ( ret = mbedtls_ecdh_read_params( &ssl->handshake->ecdh_ctx,
1957 (const unsigned char **) p, end ) ) != 0 )
1958 {
1959 MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_read_params" ), ret );
1960 return( ret );
1961 }
1962
1963 if( ssl_check_server_ecdh_params( ssl ) != 0 )
1964 {
1965 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message (ECDHE curve)" ) );
1966 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
1967 }
1968
1969 return( ret );
1970 }
1971 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
1972 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
1973 MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
1974
1975 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
1976 static int ssl_parse_server_psk_hint( mbedtls_ssl_context *ssl,
1977 unsigned char **p,
1978 unsigned char *end )
1979 {
1980 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
1981 size_t len;
1982 ((void) ssl);
1983
1984 /*
1985 * PSK parameters:
1986 *
1987 * opaque psk_identity_hint<0..2^16-1>;
1988 */
1989 len = (*p)[0] << 8 | (*p)[1];
1990 *p += 2;
1991
1992 if( (*p) + len > end )
1993 {
1994 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message (psk_identity_hint length)" ) );
1995 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
1996 }
1997
1998 /*
1999 * Note: we currently ignore the PKS identity hint, as we only allow one
2000 * PSK to be provisionned on the client. This could be changed later if
2001 * someone needs that feature.
2002 */
2003 *p += len;
2004 ret = 0;
2005
2006 return( ret );
2007 }
2008 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
2009
2010 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
2011 defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
2012 /*
2013 * Generate a pre-master secret and encrypt it with the server's RSA key
2014 */
2015 static int ssl_write_encrypted_pms( mbedtls_ssl_context *ssl,
2016 size_t offset, size_t *olen,
2017 size_t pms_offset )
2018 {
2019 int ret;
2020 size_t len_bytes = ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ? 0 : 2;
2021 unsigned char *p = ssl->handshake->premaster + pms_offset;
2022
2023 if( offset + len_bytes > MBEDTLS_SSL_MAX_CONTENT_LEN )
2024 {
2025 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small for encrypted pms" ) );
2026 return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
2027 }
2028
2029 /*
2030 * Generate (part of) the pre-master as
2031 * struct {
2032 * ProtocolVersion client_version;
2033 * opaque random[46];
2034 * } PreMasterSecret;
2035 */
2036 mbedtls_ssl_write_version( ssl->conf->max_major_ver, ssl->conf->max_minor_ver,
2037 ssl->conf->transport, p );
2038
2039 if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p + 2, 46 ) ) != 0 )
2040 {
2041 MBEDTLS_SSL_DEBUG_RET( 1, "f_rng", ret );
2042 return( ret );
2043 }
2044
2045 ssl->handshake->pmslen = 48;
2046
2047 if( ssl->session_negotiate->peer_cert == NULL )
2048 {
2049 MBEDTLS_SSL_DEBUG_MSG( 2, ( "certificate required" ) );
2050 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2051 }
2052
2053 /*
2054 * Now write it out, encrypted
2055 */
2056 if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk,
2057 MBEDTLS_PK_RSA ) )
2058 {
2059 MBEDTLS_SSL_DEBUG_MSG( 1, ( "certificate key type mismatch" ) );
2060 return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
2061 }
2062
2063 if( ( ret = mbedtls_pk_encrypt( &ssl->session_negotiate->peer_cert->pk,
2064 p, ssl->handshake->pmslen,
2065 ssl->out_msg + offset + len_bytes, olen,
2066 MBEDTLS_SSL_MAX_CONTENT_LEN - offset - len_bytes,
2067 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
2068 {
2069 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_rsa_pkcs1_encrypt", ret );
2070 return( ret );
2071 }
2072
2073 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
2074 defined(MBEDTLS_SSL_PROTO_TLS1_2)
2075 if( len_bytes == 2 )
2076 {
2077 ssl->out_msg[offset+0] = (unsigned char)( *olen >> 8 );
2078 ssl->out_msg[offset+1] = (unsigned char)( *olen );
2079 *olen += 2;
2080 }
2081 #endif
2082
2083 return( 0 );
2084 }
2085 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED ||
2086 MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
2087
2088 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
2089 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
2090 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
2091 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
2092 static int ssl_parse_signature_algorithm( mbedtls_ssl_context *ssl,
2093 unsigned char **p,
2094 unsigned char *end,
2095 mbedtls_md_type_t *md_alg,
2096 mbedtls_pk_type_t *pk_alg )
2097 {
2098 ((void) ssl);
2099 *md_alg = MBEDTLS_MD_NONE;
2100 *pk_alg = MBEDTLS_PK_NONE;
2101
2102 /* Only in TLS 1.2 */
2103 if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
2104 {
2105 return( 0 );
2106 }
2107
2108 if( (*p) + 2 > end )
2109 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2110
2111 /*
2112 * Get hash algorithm
2113 */
2114 if( ( *md_alg = mbedtls_ssl_md_alg_from_hash( (*p)[0] ) ) == MBEDTLS_MD_NONE )
2115 {
2116 MBEDTLS_SSL_DEBUG_MSG( 1, ( "Server used unsupported "
2117 "HashAlgorithm %d", *(p)[0] ) );
2118 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2119 }
2120
2121 /*
2122 * Get signature algorithm
2123 */
2124 if( ( *pk_alg = mbedtls_ssl_pk_alg_from_sig( (*p)[1] ) ) == MBEDTLS_PK_NONE )
2125 {
2126 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used unsupported "
2127 "SignatureAlgorithm %d", (*p)[1] ) );
2128 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2129 }
2130
2131 /*
2132 * Check if the hash is acceptable
2133 */
2134 if( mbedtls_ssl_check_sig_hash( ssl, *md_alg ) != 0 )
2135 {
2136 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used HashAlgorithm "
2137 "that was not offered" ) );
2138 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2139 }
2140
2141 MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used SignatureAlgorithm %d", (*p)[1] ) );
2142 MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used HashAlgorithm %d", (*p)[0] ) );
2143 *p += 2;
2144
2145 return( 0 );
2146 }
2147 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
2148 MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
2149 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
2150 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
2151
2152 #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
2153 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
2154 static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
2155 {
2156 int ret;
2157 const mbedtls_ecp_keypair *peer_key;
2158
2159 if( ssl->session_negotiate->peer_cert == NULL )
2160 {
2161 MBEDTLS_SSL_DEBUG_MSG( 2, ( "certificate required" ) );
2162 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2163 }
2164
2165 if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk,
2166 MBEDTLS_PK_ECKEY ) )
2167 {
2168 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
2169 return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
2170 }
2171
2172 peer_key = mbedtls_pk_ec( ssl->session_negotiate->peer_cert->pk );
2173
2174 if( ( ret = mbedtls_ecdh_get_params( &ssl->handshake->ecdh_ctx, peer_key,
2175 MBEDTLS_ECDH_THEIRS ) ) != 0 )
2176 {
2177 MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_get_params" ), ret );
2178 return( ret );
2179 }
2180
2181 if( ssl_check_server_ecdh_params( ssl ) != 0 )
2182 {
2183 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server certificate (ECDH curve)" ) );
2184 return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
2185 }
2186
2187 return( ret );
2188 }
2189 #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
2190 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
2191
2192 static int ssl_parse_server_key_exchange( mbedtls_ssl_context *ssl )
2193 {
2194 int ret;
2195 const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
2196 unsigned char *p, *end;
2197
2198 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server key exchange" ) );
2199
2200 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
2201 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA )
2202 {
2203 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
2204 ssl->state++;
2205 return( 0 );
2206 }
2207 ((void) p);
2208 ((void) end);
2209 #endif
2210
2211 #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
2212 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
2213 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
2214 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
2215 {
2216 if( ( ret = ssl_get_ecdh_params_from_cert( ssl ) ) != 0 )
2217 {
2218 MBEDTLS_SSL_DEBUG_RET( 1, "ssl_get_ecdh_params_from_cert", ret );
2219 return( ret );
2220 }
2221
2222 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
2223 ssl->state++;
2224 return( 0 );
2225 }
2226 ((void) p);
2227 ((void) end);
2228 #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
2229 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
2230
2231 if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
2232 {
2233 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
2234 return( ret );
2235 }
2236
2237 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
2238 {
2239 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2240 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2241 }
2242
2243 /*
2244 * ServerKeyExchange may be skipped with PSK and RSA-PSK when the server
2245 * doesn't use a psk_identity_hint
2246 */
2247 if( ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE )
2248 {
2249 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
2250 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
2251 {
2252 ssl->record_read = 1;
2253 goto exit;
2254 }
2255
2256 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2257 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2258 }
2259
2260 p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
2261 end = ssl->in_msg + ssl->in_hslen;
2262 MBEDTLS_SSL_DEBUG_BUF( 3, "server key exchange", p, end - p );
2263
2264 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
2265 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
2266 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
2267 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
2268 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
2269 {
2270 if( ssl_parse_server_psk_hint( ssl, &p, end ) != 0 )
2271 {
2272 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2273 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2274 }
2275 } /* FALLTROUGH */
2276 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
2277
2278 #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) || \
2279 defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
2280 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
2281 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
2282 ; /* nothing more to do */
2283 else
2284 #endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED ||
2285 MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
2286 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
2287 defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
2288 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA ||
2289 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK )
2290 {
2291 if( ssl_parse_server_dh_params( ssl, &p, end ) != 0 )
2292 {
2293 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2294 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2295 }
2296 }
2297 else
2298 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
2299 MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
2300 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
2301 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
2302 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
2303 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
2304 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
2305 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
2306 {
2307 if( ssl_parse_server_ecdh_params( ssl, &p, end ) != 0 )
2308 {
2309 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2310 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2311 }
2312 }
2313 else
2314 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
2315 MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
2316 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
2317 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
2318 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
2319 {
2320 ret = mbedtls_ecjpake_read_round_two( &ssl->handshake->ecjpake_ctx,
2321 p, end - p );
2322 if( ret != 0 )
2323 {
2324 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_two", ret );
2325 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2326 }
2327 }
2328 else
2329 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
2330 {
2331 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2332 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2333 }
2334
2335 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
2336 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
2337 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
2338 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA ||
2339 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
2340 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
2341 {
2342 size_t sig_len, hashlen;
2343 unsigned char hash[64];
2344 mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE;
2345 mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
2346 unsigned char *params = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
2347 size_t params_len = p - params;
2348
2349 /*
2350 * Handle the digitally-signed structure
2351 */
2352 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
2353 if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
2354 {
2355 if( ssl_parse_signature_algorithm( ssl, &p, end,
2356 &md_alg, &pk_alg ) != 0 )
2357 {
2358 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2359 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2360 }
2361
2362 if( pk_alg != mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ) )
2363 {
2364 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2365 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2366 }
2367 }
2368 else
2369 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
2370 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
2371 defined(MBEDTLS_SSL_PROTO_TLS1_1)
2372 if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 )
2373 {
2374 pk_alg = mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
2375
2376 /* Default hash for ECDSA is SHA-1 */
2377 if( pk_alg == MBEDTLS_PK_ECDSA && md_alg == MBEDTLS_MD_NONE )
2378 md_alg = MBEDTLS_MD_SHA1;
2379 }
2380 else
2381 #endif
2382 {
2383 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2384 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2385 }
2386
2387 /*
2388 * Read signature
2389 */
2390 sig_len = ( p[0] << 8 ) | p[1];
2391 p += 2;
2392
2393 if( end != p + sig_len )
2394 {
2395 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2396 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2397 }
2398
2399 MBEDTLS_SSL_DEBUG_BUF( 3, "signature", p, sig_len );
2400
2401 /*
2402 * Compute the hash that has been signed
2403 */
2404 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
2405 defined(MBEDTLS_SSL_PROTO_TLS1_1)
2406 if( md_alg == MBEDTLS_MD_NONE )
2407 {
2408 mbedtls_md5_context mbedtls_md5;
2409 mbedtls_sha1_context mbedtls_sha1;
2410
2411 mbedtls_md5_init( &mbedtls_md5 );
2412 mbedtls_sha1_init( &mbedtls_sha1 );
2413
2414 hashlen = 36;
2415
2416 /*
2417 * digitally-signed struct {
2418 * opaque md5_hash[16];
2419 * opaque sha_hash[20];
2420 * };
2421 *
2422 * md5_hash
2423 * MD5(ClientHello.random + ServerHello.random
2424 * + ServerParams);
2425 * sha_hash
2426 * SHA(ClientHello.random + ServerHello.random
2427 * + ServerParams);
2428 */
2429 mbedtls_md5_starts( &mbedtls_md5 );
2430 mbedtls_md5_update( &mbedtls_md5, ssl->handshake->randbytes, 64 );
2431 mbedtls_md5_update( &mbedtls_md5, params, params_len );
2432 mbedtls_md5_finish( &mbedtls_md5, hash );
2433
2434 mbedtls_sha1_starts( &mbedtls_sha1 );
2435 mbedtls_sha1_update( &mbedtls_sha1, ssl->handshake->randbytes, 64 );
2436 mbedtls_sha1_update( &mbedtls_sha1, params, params_len );
2437 mbedtls_sha1_finish( &mbedtls_sha1, hash + 16 );
2438
2439 mbedtls_md5_free( &mbedtls_md5 );
2440 mbedtls_sha1_free( &mbedtls_sha1 );
2441 }
2442 else
2443 #endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
2444 MBEDTLS_SSL_PROTO_TLS1_1 */
2445 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
2446 defined(MBEDTLS_SSL_PROTO_TLS1_2)
2447 if( md_alg != MBEDTLS_MD_NONE )
2448 {
2449 mbedtls_md_context_t ctx;
2450
2451 mbedtls_md_init( &ctx );
2452
2453 /* Info from md_alg will be used instead */
2454 hashlen = 0;
2455
2456 /*
2457 * digitally-signed struct {
2458 * opaque client_random[32];
2459 * opaque server_random[32];
2460 * ServerDHParams params;
2461 * };
2462 */
2463 if( ( ret = mbedtls_md_setup( &ctx,
2464 mbedtls_md_info_from_type( md_alg ), 0 ) ) != 0 )
2465 {
2466 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_md_setup", ret );
2467 return( ret );
2468 }
2469
2470 mbedtls_md_starts( &ctx );
2471 mbedtls_md_update( &ctx, ssl->handshake->randbytes, 64 );
2472 mbedtls_md_update( &ctx, params, params_len );
2473 mbedtls_md_finish( &ctx, hash );
2474 mbedtls_md_free( &ctx );
2475 }
2476 else
2477 #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
2478 MBEDTLS_SSL_PROTO_TLS1_2 */
2479 {
2480 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2481 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2482 }
2483
2484 MBEDTLS_SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen != 0 ? hashlen :
2485 (unsigned int) ( mbedtls_md_get_size( mbedtls_md_info_from_type( md_alg ) ) ) );
2486
2487 if( ssl->session_negotiate->peer_cert == NULL )
2488 {
2489 MBEDTLS_SSL_DEBUG_MSG( 2, ( "certificate required" ) );
2490 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2491 }
2492
2493 /*
2494 * Verify signature
2495 */
2496 if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) )
2497 {
2498 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2499 return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
2500 }
2501
2502 if( ( ret = mbedtls_pk_verify( &ssl->session_negotiate->peer_cert->pk,
2503 md_alg, hash, hashlen, p, sig_len ) ) != 0 )
2504 {
2505 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_verify", ret );
2506 return( ret );
2507 }
2508 }
2509 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
2510 MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
2511 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
2512
2513 exit:
2514 ssl->state++;
2515
2516 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server key exchange" ) );
2517
2518 return( 0 );
2519 }
2520
2521 #if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) && \
2522 !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) && \
2523 !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) && \
2524 !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
2525 !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \
2526 !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
2527 static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
2528 {
2529 const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
2530
2531 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
2532
2533 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
2534 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
2535 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
2536 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
2537 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
2538 {
2539 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
2540 ssl->state++;
2541 return( 0 );
2542 }
2543
2544 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2545 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2546 }
2547 #else
2548 static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
2549 {
2550 int ret;
2551 unsigned char *buf;
2552 size_t n = 0;
2553 size_t cert_type_len = 0, dn_len = 0;
2554 const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
2555
2556 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
2557
2558 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
2559 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
2560 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
2561 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
2562 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
2563 {
2564 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
2565 ssl->state++;
2566 return( 0 );
2567 }
2568
2569 if( ssl->record_read == 0 )
2570 {
2571 if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
2572 {
2573 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
2574 return( ret );
2575 }
2576
2577 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
2578 {
2579 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
2580 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2581 }
2582
2583 ssl->record_read = 1;
2584 }
2585
2586 ssl->client_auth = 0;
2587 ssl->state++;
2588
2589 if( ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST )
2590 ssl->client_auth++;
2591
2592 MBEDTLS_SSL_DEBUG_MSG( 3, ( "got %s certificate request",
2593 ssl->client_auth ? "a" : "no" ) );
2594
2595 if( ssl->client_auth == 0 )
2596 goto exit;
2597
2598 ssl->record_read = 0;
2599
2600 /*
2601 * struct {
2602 * ClientCertificateType certificate_types<1..2^8-1>;
2603 * SignatureAndHashAlgorithm
2604 * supported_signature_algorithms<2^16-1>; -- TLS 1.2 only
2605 * DistinguishedName certificate_authorities<0..2^16-1>;
2606 * } CertificateRequest;
2607 *
2608 * Since we only support a single certificate on clients, let's just
2609 * ignore all the information that's supposed to help us pick a
2610 * certificate.
2611 *
2612 * We could check that our certificate matches the request, and bail out
2613 * if it doesn't, but it's simpler to just send the certificate anyway,
2614 * and give the server the opportunity to decide if it should terminate
2615 * the connection when it doesn't like our certificate.
2616 *
2617 * Same goes for the hash in TLS 1.2's signature_algorithms: at this
2618 * point we only have one hash available (see comments in
2619 * write_certificate_verify), so let's just use what we have.
2620 *
2621 * However, we still minimally parse the message to check it is at least
2622 * superficially sane.
2623 */
2624 buf = ssl->in_msg;
2625
2626 /* certificate_types */
2627 cert_type_len = buf[mbedtls_ssl_hs_hdr_len( ssl )];
2628 n = cert_type_len;
2629
2630 if( ssl->in_hslen < mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
2631 {
2632 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
2633 return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
2634 }
2635
2636 /* supported_signature_algorithms */
2637 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
2638 if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
2639 {
2640 size_t sig_alg_len = ( ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] << 8 )
2641 | ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n] ) );
2642 #if defined(MBEDTLS_DEBUG_C)
2643 unsigned char* sig_alg = buf + mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n;
2644 size_t i;
2645
2646 for( i = 0; i < sig_alg_len; i += 2 )
2647 {
2648 MBEDTLS_SSL_DEBUG_MSG( 3, ( "Supported Signature Algorithm found: %d,%d", sig_alg[i], sig_alg[i + 1] ) );
2649 }
2650 #endif
2651
2652 n += 2 + sig_alg_len;
2653
2654 if( ssl->in_hslen < mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
2655 {
2656 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
2657 return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
2658 }
2659 }
2660 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
2661
2662 /* certificate_authorities */
2663 dn_len = ( ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] << 8 )
2664 | ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n] ) );
2665
2666 n += dn_len;
2667 if( ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n )
2668 {
2669 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
2670 return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
2671 }
2672
2673 exit:
2674 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
2675
2676 return( 0 );
2677 }
2678 #endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED &&
2679 !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED &&
2680 !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED &&
2681 !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
2682 !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED &&
2683 !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
2684
2685 static int ssl_parse_server_hello_done( mbedtls_ssl_context *ssl )
2686 {
2687 int ret;
2688
2689 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello done" ) );
2690
2691 if( ssl->record_read == 0 )
2692 {
2693 if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
2694 {
2695 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
2696 return( ret );
2697 }
2698
2699 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
2700 {
2701 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
2702 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2703 }
2704 }
2705 ssl->record_read = 0;
2706
2707 if( ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) ||
2708 ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_HELLO_DONE )
2709 {
2710 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
2711 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO_DONE );
2712 }
2713
2714 ssl->state++;
2715
2716 #if defined(MBEDTLS_SSL_PROTO_DTLS)
2717 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
2718 mbedtls_ssl_recv_flight_completed( ssl );
2719 #endif
2720
2721 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello done" ) );
2722
2723 return( 0 );
2724 }
2725
2726 static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
2727 {
2728 int ret;
2729 size_t i, n;
2730 const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
2731
2732 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write client key exchange" ) );
2733
2734 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)
2735 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA )
2736 {
2737 /*
2738 * DHM key exchange -- send G^X mod P
2739 */
2740 n = ssl->handshake->dhm_ctx.len;
2741
2742 ssl->out_msg[4] = (unsigned char)( n >> 8 );
2743 ssl->out_msg[5] = (unsigned char)( n );
2744 i = 6;
2745
2746 ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
2747 (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
2748 &ssl->out_msg[i], n,
2749 ssl->conf->f_rng, ssl->conf->p_rng );
2750 if( ret != 0 )
2751 {
2752 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_public", ret );
2753 return( ret );
2754 }
2755
2756 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X );
2757 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX );
2758
2759 if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx,
2760 ssl->handshake->premaster,
2761 MBEDTLS_PREMASTER_SIZE,
2762 &ssl->handshake->pmslen,
2763 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
2764 {
2765 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret );
2766 return( ret );
2767 }
2768
2769 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
2770 }
2771 else
2772 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED */
2773 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
2774 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
2775 defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
2776 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
2777 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
2778 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA ||
2779 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
2780 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
2781 {
2782 /*
2783 * ECDH key exchange -- send client public value
2784 */
2785 i = 4;
2786
2787 ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx,
2788 &n,
2789 &ssl->out_msg[i], 1000,
2790 ssl->conf->f_rng, ssl->conf->p_rng );
2791 if( ret != 0 )
2792 {
2793 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_public", ret );
2794 return( ret );
2795 }
2796
2797 MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
2798
2799 if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
2800 &ssl->handshake->pmslen,
2801 ssl->handshake->premaster,
2802 MBEDTLS_MPI_MAX_SIZE,
2803 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
2804 {
2805 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_calc_secret", ret );
2806 return( ret );
2807 }
2808
2809 MBEDTLS_SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z );
2810 }
2811 else
2812 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
2813 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
2814 MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
2815 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
2816 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
2817 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
2818 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
2819 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
2820 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
2821 {
2822 /*
2823 * opaque psk_identity<0..2^16-1>;
2824 */
2825 if( ssl->conf->psk == NULL || ssl->conf->psk_identity == NULL )
2826 {
2827 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key for PSK" ) );
2828 return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
2829 }
2830
2831 i = 4;
2832 n = ssl->conf->psk_identity_len;
2833
2834 if( i + 2 + n > MBEDTLS_SSL_MAX_CONTENT_LEN )
2835 {
2836 MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity too long or "
2837 "SSL buffer too short" ) );
2838 return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
2839 }
2840
2841 ssl->out_msg[i++] = (unsigned char)( n >> 8 );
2842 ssl->out_msg[i++] = (unsigned char)( n );
2843
2844 memcpy( ssl->out_msg + i, ssl->conf->psk_identity, ssl->conf->psk_identity_len );
2845 i += ssl->conf->psk_identity_len;
2846
2847 #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
2848 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK )
2849 {
2850 n = 0;
2851 }
2852 else
2853 #endif
2854 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
2855 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
2856 {
2857 if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 2 ) ) != 0 )
2858 return( ret );
2859 }
2860 else
2861 #endif
2862 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
2863 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK )
2864 {
2865 /*
2866 * ClientDiffieHellmanPublic public (DHM send G^X mod P)
2867 */
2868 n = ssl->handshake->dhm_ctx.len;
2869
2870 if( i + 2 + n > MBEDTLS_SSL_MAX_CONTENT_LEN )
2871 {
2872 MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity or DHM size too long"
2873 " or SSL buffer too short" ) );
2874 return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
2875 }
2876
2877 ssl->out_msg[i++] = (unsigned char)( n >> 8 );
2878 ssl->out_msg[i++] = (unsigned char)( n );
2879
2880 ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
2881 (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
2882 &ssl->out_msg[i], n,
2883 ssl->conf->f_rng, ssl->conf->p_rng );
2884 if( ret != 0 )
2885 {
2886 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_public", ret );
2887 return( ret );
2888 }
2889 }
2890 else
2891 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
2892 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
2893 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
2894 {
2895 /*
2896 * ClientECDiffieHellmanPublic public;
2897 */
2898 ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx, &n,
2899 &ssl->out_msg[i], MBEDTLS_SSL_MAX_CONTENT_LEN - i,
2900 ssl->conf->f_rng, ssl->conf->p_rng );
2901 if( ret != 0 )
2902 {
2903 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_public", ret );
2904 return( ret );
2905 }
2906
2907 MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
2908 }
2909 else
2910 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
2911 {
2912 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2913 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2914 }
2915
2916 if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
2917 ciphersuite_info->key_exchange ) ) != 0 )
2918 {
2919 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
2920 return( ret );
2921 }
2922 }
2923 else
2924 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
2925 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
2926 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA )
2927 {
2928 i = 4;
2929 if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 0 ) ) != 0 )
2930 return( ret );
2931 }
2932 else
2933 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
2934 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
2935 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
2936 {
2937 i = 4;
2938
2939 ret = mbedtls_ecjpake_write_round_two( &ssl->handshake->ecjpake_ctx,
2940 ssl->out_msg + i, MBEDTLS_SSL_MAX_CONTENT_LEN - i, &n,
2941 ssl->conf->f_rng, ssl->conf->p_rng );
2942 if( ret != 0 )
2943 {
2944 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_write_round_two", ret );
2945 return( ret );
2946 }
2947
2948 ret = mbedtls_ecjpake_derive_secret( &ssl->handshake->ecjpake_ctx,
2949 ssl->handshake->premaster, 32, &ssl->handshake->pmslen,
2950 ssl->conf->f_rng, ssl->conf->p_rng );
2951 if( ret != 0 )
2952 {
2953 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_derive_secret", ret );
2954 return( ret );
2955 }
2956 }
2957 else
2958 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
2959 {
2960 ((void) ciphersuite_info);
2961 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2962 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2963 }
2964
2965 ssl->out_msglen = i + n;
2966 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
2967 ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE;
2968
2969 ssl->state++;
2970
2971 if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 )
2972 {
2973 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
2974 return( ret );
2975 }
2976
2977 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write client key exchange" ) );
2978
2979 return( 0 );
2980 }
2981
2982 #if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) && \
2983 !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) && \
2984 !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) && \
2985 !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
2986 !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \
2987 !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
2988 static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
2989 {
2990 const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
2991 int ret;
2992
2993 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
2994
2995 if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
2996 {
2997 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
2998 return( ret );
2999 }
3000
3001 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
3002 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
3003 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
3004 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
3005 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
3006 {
3007 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
3008 ssl->state++;
3009 return( 0 );
3010 }
3011
3012 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3013 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3014 }
3015 #else
3016 static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
3017 {
3018 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
3019 const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
3020 size_t n = 0, offset = 0;
3021 unsigned char hash[48];
3022 unsigned char *hash_start = hash;
3023 mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE;
3024 unsigned int hashlen;
3025
3026 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
3027
3028 if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
3029 {
3030 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
3031 return( ret );
3032 }
3033
3034 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
3035 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
3036 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
3037 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
3038 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
3039 {
3040 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
3041 ssl->state++;
3042 return( 0 );
3043 }
3044
3045 if( ssl->client_auth == 0 || mbedtls_ssl_own_cert( ssl ) == NULL )
3046 {
3047 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
3048 ssl->state++;
3049 return( 0 );
3050 }
3051
3052 if( mbedtls_ssl_own_key( ssl ) == NULL )
3053 {
3054 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key for certificate" ) );
3055 return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
3056 }
3057
3058 /*
3059 * Make an RSA signature of the handshake digests
3060 */
3061 ssl->handshake->calc_verify( ssl, hash );
3062
3063 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
3064 defined(MBEDTLS_SSL_PROTO_TLS1_1)
3065 if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
3066 {
3067 /*
3068 * digitally-signed struct {
3069 * opaque md5_hash[16];
3070 * opaque sha_hash[20];
3071 * };
3072 *
3073 * md5_hash
3074 * MD5(handshake_messages);
3075 *
3076 * sha_hash
3077 * SHA(handshake_messages);
3078 */
3079 hashlen = 36;
3080 md_alg = MBEDTLS_MD_NONE;
3081
3082 /*
3083 * For ECDSA, default hash is SHA-1 only
3084 */
3085 if( mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_ECDSA ) )
3086 {
3087 hash_start += 16;
3088 hashlen -= 16;
3089 md_alg = MBEDTLS_MD_SHA1;
3090 }
3091 }
3092 else
3093 #endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
3094 MBEDTLS_SSL_PROTO_TLS1_1 */
3095 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
3096 if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
3097 {
3098 /*
3099 * digitally-signed struct {
3100 * opaque handshake_messages[handshake_messages_length];
3101 * };
3102 *
3103 * Taking shortcut here. We assume that the server always allows the
3104 * PRF Hash function and has sent it in the allowed signature
3105 * algorithms list received in the Certificate Request message.
3106 *
3107 * Until we encounter a server that does not, we will take this
3108 * shortcut.
3109 *
3110 * Reason: Otherwise we should have running hashes for SHA512 and SHA224
3111 * in order to satisfy 'weird' needs from the server side.
3112 */
3113 if( ssl->transform_negotiate->ciphersuite_info->mac ==
3114 MBEDTLS_MD_SHA384 )
3115 {
3116 md_alg = MBEDTLS_MD_SHA384;
3117 ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA384;
3118 }
3119 else
3120 {
3121 md_alg = MBEDTLS_MD_SHA256;
3122 ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA256;
3123 }
3124 ssl->out_msg[5] = mbedtls_ssl_sig_from_pk( mbedtls_ssl_own_key( ssl ) );
3125
3126 /* Info from md_alg will be used instead */
3127 hashlen = 0;
3128 offset = 2;
3129 }
3130 else
3131 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
3132 {
3133 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3134 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3135 }
3136
3137 if( ( ret = mbedtls_pk_sign( mbedtls_ssl_own_key( ssl ), md_alg, hash_start, hashlen,
3138 ssl->out_msg + 6 + offset, &n,
3139 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
3140 {
3141 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_sign", ret );
3142 return( ret );
3143 }
3144
3145 ssl->out_msg[4 + offset] = (unsigned char)( n >> 8 );
3146 ssl->out_msg[5 + offset] = (unsigned char)( n );
3147
3148 ssl->out_msglen = 6 + n + offset;
3149 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
3150 ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE_VERIFY;
3151
3152 ssl->state++;
3153
3154 if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 )
3155 {
3156 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
3157 return( ret );
3158 }
3159
3160 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate verify" ) );
3161
3162 return( ret );
3163 }
3164 #endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED &&
3165 !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED &&
3166 !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED &&
3167 !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
3168 !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED &&
3169 !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
3170
3171 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
3172 static int ssl_parse_new_session_ticket( mbedtls_ssl_context *ssl )
3173 {
3174 int ret;
3175 uint32_t lifetime;
3176 size_t ticket_len;
3177 unsigned char *ticket;
3178 const unsigned char *msg;
3179
3180 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse new session ticket" ) );
3181
3182 if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
3183 {
3184 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
3185 return( ret );
3186 }
3187
3188 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
3189 {
3190 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
3191 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
3192 }
3193
3194 /*
3195 * struct {
3196 * uint32 ticket_lifetime_hint;
3197 * opaque ticket<0..2^16-1>;
3198 * } NewSessionTicket;
3199 *
3200 * 0 . 3 ticket_lifetime_hint
3201 * 4 . 5 ticket_len (n)
3202 * 6 . 5+n ticket content
3203 */
3204 if( ssl->in_msg[0] != MBEDTLS_SSL_HS_NEW_SESSION_TICKET ||
3205 ssl->in_hslen < 6 + mbedtls_ssl_hs_hdr_len( ssl ) )
3206 {
3207 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
3208 return( MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
3209 }
3210
3211 msg = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
3212
3213 lifetime = ( msg[0] << 24 ) | ( msg[1] << 16 ) |
3214 ( msg[2] << 8 ) | ( msg[3] );
3215
3216 ticket_len = ( msg[4] << 8 ) | ( msg[5] );
3217
3218 if( ticket_len + 6 + mbedtls_ssl_hs_hdr_len( ssl ) != ssl->in_hslen )
3219 {
3220 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
3221 return( MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
3222 }
3223
3224 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket length: %d", ticket_len ) );
3225
3226 /* We're not waiting for a NewSessionTicket message any more */
3227 ssl->handshake->new_session_ticket = 0;
3228 ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
3229
3230 /*
3231 * Zero-length ticket means the server changed his mind and doesn't want
3232 * to send a ticket after all, so just forget it
3233 */
3234 if( ticket_len == 0 )
3235 return( 0 );
3236
3237 mbedtls_zeroize( ssl->session_negotiate->ticket,
3238 ssl->session_negotiate->ticket_len );
3239 mbedtls_free( ssl->session_negotiate->ticket );
3240 ssl->session_negotiate->ticket = NULL;
3241 ssl->session_negotiate->ticket_len = 0;
3242
3243 if( ( ticket = mbedtls_calloc( 1, ticket_len ) ) == NULL )
3244 {
3245 MBEDTLS_SSL_DEBUG_MSG( 1, ( "ticket alloc failed" ) );
3246 return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
3247 }
3248
3249 memcpy( ticket, msg + 6, ticket_len );
3250
3251 ssl->session_negotiate->ticket = ticket;
3252 ssl->session_negotiate->ticket_len = ticket_len;
3253 ssl->session_negotiate->ticket_lifetime = lifetime;
3254
3255 /*
3256 * RFC 5077 section 3.4:
3257 * "If the client receives a session ticket from the server, then it
3258 * discards any Session ID that was sent in the ServerHello."
3259 */
3260 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket in use, discarding session id" ) );
3261 ssl->session_negotiate->id_len = 0;
3262
3263 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse new session ticket" ) );
3264
3265 return( 0 );
3266 }
3267 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
3268
3269 /*
3270 * SSL handshake -- client side -- single step
3271 */
3272 int mbedtls_ssl_handshake_client_step( mbedtls_ssl_context *ssl )
3273 {
3274 int ret = 0;
3275
3276 if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->handshake == NULL )
3277 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
3278
3279 MBEDTLS_SSL_DEBUG_MSG( 2, ( "client state: %d", ssl->state ) );
3280
3281 if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
3282 return( ret );
3283
3284 #if defined(MBEDTLS_SSL_PROTO_DTLS)
3285 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
3286 ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
3287 {
3288 if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 )
3289 return( ret );
3290 }
3291 #endif
3292
3293 /* Change state now, so that it is right in mbedtls_ssl_read_record(), used
3294 * by DTLS for dropping out-of-sequence ChangeCipherSpec records */
3295 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
3296 if( ssl->state == MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC &&
3297 ssl->handshake->new_session_ticket != 0 )
3298 {
3299 ssl->state = MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET;
3300 }
3301 #endif
3302
3303 switch( ssl->state )
3304 {
3305 case MBEDTLS_SSL_HELLO_REQUEST:
3306 ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
3307 break;
3308
3309 /*
3310 * ==> ClientHello
3311 */
3312 case MBEDTLS_SSL_CLIENT_HELLO:
3313 ret = ssl_write_client_hello( ssl );
3314 break;
3315
3316 /*
3317 * <== ServerHello
3318 * Certificate
3319 * ( ServerKeyExchange )
3320 * ( CertificateRequest )
3321 * ServerHelloDone
3322 */
3323 case MBEDTLS_SSL_SERVER_HELLO:
3324 ret = ssl_parse_server_hello( ssl );
3325 break;
3326
3327 case MBEDTLS_SSL_SERVER_CERTIFICATE:
3328 ret = mbedtls_ssl_parse_certificate( ssl );
3329 break;
3330
3331 case MBEDTLS_SSL_SERVER_KEY_EXCHANGE:
3332 ret = ssl_parse_server_key_exchange( ssl );
3333 break;
3334
3335 case MBEDTLS_SSL_CERTIFICATE_REQUEST:
3336 ret = ssl_parse_certificate_request( ssl );
3337 break;
3338
3339 case MBEDTLS_SSL_SERVER_HELLO_DONE:
3340 ret = ssl_parse_server_hello_done( ssl );
3341 break;
3342
3343 /*
3344 * ==> ( Certificate/Alert )
3345 * ClientKeyExchange
3346 * ( CertificateVerify )
3347 * ChangeCipherSpec
3348 * Finished
3349 */
3350 case MBEDTLS_SSL_CLIENT_CERTIFICATE:
3351 ret = mbedtls_ssl_write_certificate( ssl );
3352 break;
3353
3354 case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE:
3355 ret = ssl_write_client_key_exchange( ssl );
3356 break;
3357
3358 case MBEDTLS_SSL_CERTIFICATE_VERIFY:
3359 ret = ssl_write_certificate_verify( ssl );
3360 break;
3361
3362 case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC:
3363 ret = mbedtls_ssl_write_change_cipher_spec( ssl );
3364 break;
3365
3366 case MBEDTLS_SSL_CLIENT_FINISHED:
3367 ret = mbedtls_ssl_write_finished( ssl );
3368 break;
3369
3370 /*
3371 * <== ( NewSessionTicket )
3372 * ChangeCipherSpec
3373 * Finished
3374 */
3375 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
3376 case MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET:
3377 ret = ssl_parse_new_session_ticket( ssl );
3378 break;
3379 #endif
3380
3381 case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC:
3382 ret = mbedtls_ssl_parse_change_cipher_spec( ssl );
3383 break;
3384
3385 case MBEDTLS_SSL_SERVER_FINISHED:
3386 ret = mbedtls_ssl_parse_finished( ssl );
3387 break;
3388
3389 case MBEDTLS_SSL_FLUSH_BUFFERS:
3390 MBEDTLS_SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
3391 ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP;
3392 break;
3393
3394 case MBEDTLS_SSL_HANDSHAKE_WRAPUP:
3395 mbedtls_ssl_handshake_wrapup( ssl );
3396 break;
3397
3398 default:
3399 MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
3400 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
3401 }
3402
3403 return( ret );
3404 }
3405 #endif /* MBEDTLS_SSL_CLI_C */
3406
