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 #include "mbedtls/platform_util.h"
52 #endif
53
54 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
ssl_write_hostname_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)55 static void ssl_write_hostname_ext( mbedtls_ssl_context *ssl,
56 unsigned char *buf,
57 size_t *olen )
58 {
59 unsigned char *p = buf;
60 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
61 size_t hostname_len;
62
63 *olen = 0;
64
65 if( ssl->hostname == NULL )
66 return;
67
68 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding server name extension: %s",
69 ssl->hostname ) );
70
71 hostname_len = strlen( ssl->hostname );
72
73 if( end < p || (size_t)( end - p ) < hostname_len + 9 )
74 {
75 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
76 return;
77 }
78
79 /*
80 * Sect. 3, RFC 6066 (TLS Extensions Definitions)
81 *
82 * In order to provide any of the server names, clients MAY include an
83 * extension of type "server_name" in the (extended) client hello. The
84 * "extension_data" field of this extension SHALL contain
85 * "ServerNameList" where:
86 *
87 * struct {
88 * NameType name_type;
89 * select (name_type) {
90 * case host_name: HostName;
91 * } name;
92 * } ServerName;
93 *
94 * enum {
95 * host_name(0), (255)
96 * } NameType;
97 *
98 * opaque HostName<1..2^16-1>;
99 *
100 * struct {
101 * ServerName server_name_list<1..2^16-1>
102 * } ServerNameList;
103 *
104 */
105 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME >> 8 ) & 0xFF );
106 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME ) & 0xFF );
107
108 *p++ = (unsigned char)( ( (hostname_len + 5) >> 8 ) & 0xFF );
109 *p++ = (unsigned char)( ( (hostname_len + 5) ) & 0xFF );
110
111 *p++ = (unsigned char)( ( (hostname_len + 3) >> 8 ) & 0xFF );
112 *p++ = (unsigned char)( ( (hostname_len + 3) ) & 0xFF );
113
114 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME ) & 0xFF );
115 *p++ = (unsigned char)( ( hostname_len >> 8 ) & 0xFF );
116 *p++ = (unsigned char)( ( hostname_len ) & 0xFF );
117
118 memcpy( p, ssl->hostname, hostname_len );
119
120 *olen = hostname_len + 9;
121 }
122 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
123
124 #if defined(MBEDTLS_SSL_RENEGOTIATION)
ssl_write_renegotiation_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)125 static void ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl,
126 unsigned char *buf,
127 size_t *olen )
128 {
129 unsigned char *p = buf;
130 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
131
132 *olen = 0;
133
134 /* We're always including an TLS_EMPTY_RENEGOTIATION_INFO_SCSV in the
135 * initial ClientHello, in which case also adding the renegotiation
136 * info extension is NOT RECOMMENDED as per RFC 5746 Section 3.4. */
137 if( ssl->renego_status != MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
138 return;
139
140 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding renegotiation extension" ) );
141
142 if( end < p || (size_t)( end - p ) < 5 + ssl->verify_data_len )
143 {
144 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
145 return;
146 }
147
148 /*
149 * Secure renegotiation
150 */
151 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO >> 8 ) & 0xFF );
152 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO ) & 0xFF );
153
154 *p++ = 0x00;
155 *p++ = ( ssl->verify_data_len + 1 ) & 0xFF;
156 *p++ = ssl->verify_data_len & 0xFF;
157
158 memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
159
160 *olen = 5 + ssl->verify_data_len;
161 }
162 #endif /* MBEDTLS_SSL_RENEGOTIATION */
163
164 /*
165 * Only if we handle at least one key exchange that needs signatures.
166 */
167 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
168 defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
ssl_write_signature_algorithms_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)169 static void ssl_write_signature_algorithms_ext( mbedtls_ssl_context *ssl,
170 unsigned char *buf,
171 size_t *olen )
172 {
173 unsigned char *p = buf;
174 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
175 size_t sig_alg_len = 0;
176 const int *md;
177 #if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_C)
178 unsigned char *sig_alg_list = buf + 6;
179 #endif
180
181 *olen = 0;
182
183 if( ssl->conf->max_minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
184 return;
185
186 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding signature_algorithms extension" ) );
187
188 for( md = ssl->conf->sig_hashes; *md != MBEDTLS_MD_NONE; md++ )
189 {
190 #if defined(MBEDTLS_ECDSA_C)
191 sig_alg_len += 2;
192 #endif
193 #if defined(MBEDTLS_RSA_C)
194 sig_alg_len += 2;
195 #endif
196 }
197
198 if( end < p || (size_t)( end - p ) < sig_alg_len + 6 )
199 {
200 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
201 return;
202 }
203
204 /*
205 * Prepare signature_algorithms extension (TLS 1.2)
206 */
207 sig_alg_len = 0;
208
209 for( md = ssl->conf->sig_hashes; *md != MBEDTLS_MD_NONE; md++ )
210 {
211 #if defined(MBEDTLS_ECDSA_C)
212 sig_alg_list[sig_alg_len++] = mbedtls_ssl_hash_from_md_alg( *md );
213 sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
214 #endif
215 #if defined(MBEDTLS_RSA_C)
216 sig_alg_list[sig_alg_len++] = mbedtls_ssl_hash_from_md_alg( *md );
217 sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
218 #endif
219 }
220
221 /*
222 * enum {
223 * none(0), md5(1), sha1(2), sha224(3), sha256(4), sha384(5),
224 * sha512(6), (255)
225 * } HashAlgorithm;
226 *
227 * enum { anonymous(0), rsa(1), dsa(2), ecdsa(3), (255) }
228 * SignatureAlgorithm;
229 *
230 * struct {
231 * HashAlgorithm hash;
232 * SignatureAlgorithm signature;
233 * } SignatureAndHashAlgorithm;
234 *
235 * SignatureAndHashAlgorithm
236 * supported_signature_algorithms<2..2^16-2>;
237 */
238 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SIG_ALG >> 8 ) & 0xFF );
239 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SIG_ALG ) & 0xFF );
240
241 *p++ = (unsigned char)( ( ( sig_alg_len + 2 ) >> 8 ) & 0xFF );
242 *p++ = (unsigned char)( ( ( sig_alg_len + 2 ) ) & 0xFF );
243
244 *p++ = (unsigned char)( ( sig_alg_len >> 8 ) & 0xFF );
245 *p++ = (unsigned char)( ( sig_alg_len ) & 0xFF );
246
247 *olen = 6 + sig_alg_len;
248 }
249 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
250 MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
251
252 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
253 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl_write_supported_elliptic_curves_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)254 static void ssl_write_supported_elliptic_curves_ext( mbedtls_ssl_context *ssl,
255 unsigned char *buf,
256 size_t *olen )
257 {
258 unsigned char *p = buf;
259 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
260 unsigned char *elliptic_curve_list = p + 6;
261 size_t elliptic_curve_len = 0;
262 const mbedtls_ecp_curve_info *info;
263 #if defined(MBEDTLS_ECP_C)
264 const mbedtls_ecp_group_id *grp_id;
265 #else
266 ((void) ssl);
267 #endif
268
269 *olen = 0;
270
271 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_elliptic_curves extension" ) );
272
273 #if defined(MBEDTLS_ECP_C)
274 for( grp_id = ssl->conf->curve_list; *grp_id != MBEDTLS_ECP_DP_NONE; grp_id++ )
275 #else
276 for( info = mbedtls_ecp_curve_list(); info->grp_id != MBEDTLS_ECP_DP_NONE; info++ )
277 #endif
278 {
279 #if defined(MBEDTLS_ECP_C)
280 info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
281 #endif
282 if( info == NULL )
283 {
284 MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid curve in ssl configuration" ) );
285 return;
286 }
287
288 elliptic_curve_len += 2;
289 }
290
291 if( end < p || (size_t)( end - p ) < 6 + elliptic_curve_len )
292 {
293 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
294 return;
295 }
296
297 elliptic_curve_len = 0;
298
299 #if defined(MBEDTLS_ECP_C)
300 for( grp_id = ssl->conf->curve_list; *grp_id != MBEDTLS_ECP_DP_NONE; grp_id++ )
301 #else
302 for( info = mbedtls_ecp_curve_list(); info->grp_id != MBEDTLS_ECP_DP_NONE; info++ )
303 #endif
304 {
305 #if defined(MBEDTLS_ECP_C)
306 info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
307 #endif
308 elliptic_curve_list[elliptic_curve_len++] = info->tls_id >> 8;
309 elliptic_curve_list[elliptic_curve_len++] = info->tls_id & 0xFF;
310 }
311
312 if( elliptic_curve_len == 0 )
313 return;
314
315 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES >> 8 ) & 0xFF );
316 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES ) & 0xFF );
317
318 *p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) >> 8 ) & 0xFF );
319 *p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) ) & 0xFF );
320
321 *p++ = (unsigned char)( ( ( elliptic_curve_len ) >> 8 ) & 0xFF );
322 *p++ = (unsigned char)( ( ( elliptic_curve_len ) ) & 0xFF );
323
324 *olen = 6 + elliptic_curve_len;
325 }
326
ssl_write_supported_point_formats_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)327 static void ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl,
328 unsigned char *buf,
329 size_t *olen )
330 {
331 unsigned char *p = buf;
332 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
333
334 *olen = 0;
335
336 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_point_formats extension" ) );
337
338 if( end < p || (size_t)( end - p ) < 6 )
339 {
340 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
341 return;
342 }
343
344 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF );
345 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS ) & 0xFF );
346
347 *p++ = 0x00;
348 *p++ = 2;
349
350 *p++ = 1;
351 *p++ = MBEDTLS_ECP_PF_UNCOMPRESSED;
352
353 *olen = 6;
354 }
355 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
356 MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
357
358 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl_write_ecjpake_kkpp_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)359 static void ssl_write_ecjpake_kkpp_ext( mbedtls_ssl_context *ssl,
360 unsigned char *buf,
361 size_t *olen )
362 {
363 int ret;
364 unsigned char *p = buf;
365 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
366 size_t kkpp_len;
367
368 *olen = 0;
369
370 /* Skip costly extension if we can't use EC J-PAKE anyway */
371 if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
372 return;
373
374 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding ecjpake_kkpp extension" ) );
375
376 if( end - p < 4 )
377 {
378 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
379 return;
380 }
381
382 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP >> 8 ) & 0xFF );
383 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP ) & 0xFF );
384
385 /*
386 * We may need to send ClientHello multiple times for Hello verification.
387 * We don't want to compute fresh values every time (both for performance
388 * and consistency reasons), so cache the extension content.
389 */
390 if( ssl->handshake->ecjpake_cache == NULL ||
391 ssl->handshake->ecjpake_cache_len == 0 )
392 {
393 MBEDTLS_SSL_DEBUG_MSG( 3, ( "generating new ecjpake parameters" ) );
394
395 ret = mbedtls_ecjpake_write_round_one( &ssl->handshake->ecjpake_ctx,
396 p + 2, end - p - 2, &kkpp_len,
397 ssl->conf->f_rng, ssl->conf->p_rng );
398 if( ret != 0 )
399 {
400 MBEDTLS_SSL_DEBUG_RET( 1 , "mbedtls_ecjpake_write_round_one", ret );
401 return;
402 }
403
404 ssl->handshake->ecjpake_cache = mbedtls_calloc( 1, kkpp_len );
405 if( ssl->handshake->ecjpake_cache == NULL )
406 {
407 MBEDTLS_SSL_DEBUG_MSG( 1, ( "allocation failed" ) );
408 return;
409 }
410
411 memcpy( ssl->handshake->ecjpake_cache, p + 2, kkpp_len );
412 ssl->handshake->ecjpake_cache_len = kkpp_len;
413 }
414 else
415 {
416 MBEDTLS_SSL_DEBUG_MSG( 3, ( "re-using cached ecjpake parameters" ) );
417
418 kkpp_len = ssl->handshake->ecjpake_cache_len;
419
420 if( (size_t)( end - p - 2 ) < kkpp_len )
421 {
422 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
423 return;
424 }
425
426 memcpy( p + 2, ssl->handshake->ecjpake_cache, kkpp_len );
427 }
428
429 *p++ = (unsigned char)( ( kkpp_len >> 8 ) & 0xFF );
430 *p++ = (unsigned char)( ( kkpp_len ) & 0xFF );
431
432 *olen = kkpp_len + 4;
433 }
434 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
435
436 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
ssl_write_max_fragment_length_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)437 static void ssl_write_max_fragment_length_ext( mbedtls_ssl_context *ssl,
438 unsigned char *buf,
439 size_t *olen )
440 {
441 unsigned char *p = buf;
442 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
443
444 *olen = 0;
445
446 if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ) {
447 return;
448 }
449
450 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding max_fragment_length extension" ) );
451
452 if( end < p || (size_t)( end - p ) < 5 )
453 {
454 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
455 return;
456 }
457
458 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH >> 8 ) & 0xFF );
459 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH ) & 0xFF );
460
461 *p++ = 0x00;
462 *p++ = 1;
463
464 *p++ = ssl->conf->mfl_code;
465
466 *olen = 5;
467 }
468 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
469
470 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
ssl_write_truncated_hmac_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)471 static void ssl_write_truncated_hmac_ext( mbedtls_ssl_context *ssl,
472 unsigned char *buf, size_t *olen )
473 {
474 unsigned char *p = buf;
475 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
476
477 *olen = 0;
478
479 if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED )
480 {
481 return;
482 }
483
484 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding truncated_hmac extension" ) );
485
486 if( end < p || (size_t)( end - p ) < 4 )
487 {
488 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
489 return;
490 }
491
492 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF );
493 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC ) & 0xFF );
494
495 *p++ = 0x00;
496 *p++ = 0x00;
497
498 *olen = 4;
499 }
500 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
501
502 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
ssl_write_encrypt_then_mac_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)503 static void ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
504 unsigned char *buf, size_t *olen )
505 {
506 unsigned char *p = buf;
507 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
508
509 *olen = 0;
510
511 if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
512 ssl->conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
513 {
514 return;
515 }
516
517 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding encrypt_then_mac "
518 "extension" ) );
519
520 if( end < p || (size_t)( end - p ) < 4 )
521 {
522 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
523 return;
524 }
525
526 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC >> 8 ) & 0xFF );
527 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC ) & 0xFF );
528
529 *p++ = 0x00;
530 *p++ = 0x00;
531
532 *olen = 4;
533 }
534 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
535
536 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
ssl_write_extended_ms_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)537 static void ssl_write_extended_ms_ext( mbedtls_ssl_context *ssl,
538 unsigned char *buf, size_t *olen )
539 {
540 unsigned char *p = buf;
541 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
542
543 *olen = 0;
544
545 if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
546 ssl->conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
547 {
548 return;
549 }
550
551 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding extended_master_secret "
552 "extension" ) );
553
554 if( end < p || (size_t)( end - p ) < 4 )
555 {
556 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
557 return;
558 }
559
560 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF );
561 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET ) & 0xFF );
562
563 *p++ = 0x00;
564 *p++ = 0x00;
565
566 *olen = 4;
567 }
568 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
569
570 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
ssl_write_session_ticket_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)571 static void ssl_write_session_ticket_ext( mbedtls_ssl_context *ssl,
572 unsigned char *buf, size_t *olen )
573 {
574 unsigned char *p = buf;
575 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
576 size_t tlen = ssl->session_negotiate->ticket_len;
577
578 *olen = 0;
579
580 if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED )
581 {
582 return;
583 }
584
585 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding session ticket extension" ) );
586
587 if( end < p || (size_t)( end - p ) < 4 + tlen )
588 {
589 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
590 return;
591 }
592
593 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF );
594 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET ) & 0xFF );
595
596 *p++ = (unsigned char)( ( tlen >> 8 ) & 0xFF );
597 *p++ = (unsigned char)( ( tlen ) & 0xFF );
598
599 *olen = 4;
600
601 if( ssl->session_negotiate->ticket == NULL || tlen == 0 )
602 {
603 return;
604 }
605
606 MBEDTLS_SSL_DEBUG_MSG( 3, ( "sending session ticket of length %d", tlen ) );
607
608 memcpy( p, ssl->session_negotiate->ticket, tlen );
609
610 *olen += tlen;
611 }
612 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
613
614 #if defined(MBEDTLS_SSL_ALPN)
ssl_write_alpn_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)615 static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl,
616 unsigned char *buf, size_t *olen )
617 {
618 unsigned char *p = buf;
619 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
620 size_t alpnlen = 0;
621 const char **cur;
622
623 *olen = 0;
624
625 if( ssl->conf->alpn_list == NULL )
626 {
627 return;
628 }
629
630 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding alpn extension" ) );
631
632 for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
633 alpnlen += (unsigned char)( strlen( *cur ) & 0xFF ) + 1;
634
635 if( end < p || (size_t)( end - p ) < 6 + alpnlen )
636 {
637 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
638 return;
639 }
640
641 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN >> 8 ) & 0xFF );
642 *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN ) & 0xFF );
643
644 /*
645 * opaque ProtocolName<1..2^8-1>;
646 *
647 * struct {
648 * ProtocolName protocol_name_list<2..2^16-1>
649 * } ProtocolNameList;
650 */
651
652 /* Skip writing extension and list length for now */
653 p += 4;
654
655 for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
656 {
657 *p = (unsigned char)( strlen( *cur ) & 0xFF );
658 memcpy( p + 1, *cur, *p );
659 p += 1 + *p;
660 }
661
662 *olen = p - buf;
663
664 /* List length = olen - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */
665 buf[4] = (unsigned char)( ( ( *olen - 6 ) >> 8 ) & 0xFF );
666 buf[5] = (unsigned char)( ( ( *olen - 6 ) ) & 0xFF );
667
668 /* Extension length = olen - 2 (ext_type) - 2 (ext_len) */
669 buf[2] = (unsigned char)( ( ( *olen - 4 ) >> 8 ) & 0xFF );
670 buf[3] = (unsigned char)( ( ( *olen - 4 ) ) & 0xFF );
671 }
672 #endif /* MBEDTLS_SSL_ALPN */
673
674 /*
675 * Generate random bytes for ClientHello
676 */
ssl_generate_random(mbedtls_ssl_context * ssl)677 static int ssl_generate_random( mbedtls_ssl_context *ssl )
678 {
679 int ret;
680 unsigned char *p = ssl->handshake->randbytes;
681 #if defined(MBEDTLS_HAVE_TIME)
682 mbedtls_time_t t;
683 #endif
684
685 /*
686 * When responding to a verify request, MUST reuse random (RFC 6347 4.2.1)
687 */
688 #if defined(MBEDTLS_SSL_PROTO_DTLS)
689 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
690 ssl->handshake->verify_cookie != NULL )
691 {
692 return( 0 );
693 }
694 #endif
695
696 #if defined(MBEDTLS_HAVE_TIME)
697 t = mbedtls_time( NULL );
698 *p++ = (unsigned char)( t >> 24 );
699 *p++ = (unsigned char)( t >> 16 );
700 *p++ = (unsigned char)( t >> 8 );
701 *p++ = (unsigned char)( t );
702
703 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, current time: %lu", t ) );
704 #else
705 if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 4 ) ) != 0 )
706 return( ret );
707
708 p += 4;
709 #endif /* MBEDTLS_HAVE_TIME */
710
711 if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 28 ) ) != 0 )
712 return( ret );
713
714 return( 0 );
715 }
716
717 /**
718 * \brief Validate cipher suite against config in SSL context.
719 *
720 * \param suite_info cipher suite to validate
721 * \param ssl SSL context
722 * \param min_minor_ver Minimal minor version to accept a cipher suite
723 * \param max_minor_ver Maximal minor version to accept a cipher suite
724 *
725 * \return 0 if valid, else 1
726 */
ssl_validate_ciphersuite(const mbedtls_ssl_ciphersuite_t * suite_info,const mbedtls_ssl_context * ssl,int min_minor_ver,int max_minor_ver)727 static int ssl_validate_ciphersuite( const mbedtls_ssl_ciphersuite_t * suite_info,
728 const mbedtls_ssl_context * ssl,
729 int min_minor_ver, int max_minor_ver )
730 {
731 (void) ssl;
732 if( suite_info == NULL )
733 return( 1 );
734
735 if( suite_info->min_minor_ver > max_minor_ver ||
736 suite_info->max_minor_ver < min_minor_ver )
737 return( 1 );
738
739 #if defined(MBEDTLS_SSL_PROTO_DTLS)
740 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
741 ( suite_info->flags & MBEDTLS_CIPHERSUITE_NODTLS ) )
742 return( 1 );
743 #endif
744
745 #if defined(MBEDTLS_ARC4_C)
746 if( ssl->conf->arc4_disabled == MBEDTLS_SSL_ARC4_DISABLED &&
747 suite_info->cipher == MBEDTLS_CIPHER_ARC4_128 )
748 return( 1 );
749 #endif
750
751 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
752 if( suite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE &&
753 mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
754 return( 1 );
755 #endif
756
757 return( 0 );
758 }
759
ssl_write_client_hello(mbedtls_ssl_context * ssl)760 static int ssl_write_client_hello( mbedtls_ssl_context *ssl )
761 {
762 int ret;
763 size_t i, n, olen, ext_len = 0;
764 unsigned char *buf;
765 unsigned char *p, *q;
766 unsigned char offer_compress;
767 const int *ciphersuites;
768 const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
769 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
770 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
771 int uses_ec = 0;
772 #endif
773
774 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write client hello" ) );
775
776 if( ssl->conf->f_rng == NULL )
777 {
778 MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided") );
779 return( MBEDTLS_ERR_SSL_NO_RNG );
780 }
781
782 #if defined(MBEDTLS_SSL_RENEGOTIATION)
783 if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
784 #endif
785 {
786 ssl->major_ver = ssl->conf->min_major_ver;
787 ssl->minor_ver = ssl->conf->min_minor_ver;
788 }
789
790 if( ssl->conf->max_major_ver == 0 )
791 {
792 MBEDTLS_SSL_DEBUG_MSG( 1, ( "configured max major version is invalid, "
793 "consider using mbedtls_ssl_config_defaults()" ) );
794 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
795 }
796
797 /*
798 * 0 . 0 handshake type
799 * 1 . 3 handshake length
800 * 4 . 5 highest version supported
801 * 6 . 9 current UNIX time
802 * 10 . 37 random bytes
803 */
804 buf = ssl->out_msg;
805 p = buf + 4;
806
807 mbedtls_ssl_write_version( ssl->conf->max_major_ver, ssl->conf->max_minor_ver,
808 ssl->conf->transport, p );
809 p += 2;
810
811 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, max version: [%d:%d]",
812 buf[4], buf[5] ) );
813
814 if( ( ret = ssl_generate_random( ssl ) ) != 0 )
815 {
816 MBEDTLS_SSL_DEBUG_RET( 1, "ssl_generate_random", ret );
817 return( ret );
818 }
819
820 memcpy( p, ssl->handshake->randbytes, 32 );
821 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", p, 32 );
822 p += 32;
823
824 /*
825 * 38 . 38 session id length
826 * 39 . 39+n session id
827 * 39+n . 39+n DTLS only: cookie length (1 byte)
828 * 40+n . .. DTSL only: cookie
829 * .. . .. ciphersuitelist length (2 bytes)
830 * .. . .. ciphersuitelist
831 * .. . .. compression methods length (1 byte)
832 * .. . .. compression methods
833 * .. . .. extensions length (2 bytes)
834 * .. . .. extensions
835 */
836 n = ssl->session_negotiate->id_len;
837
838 if( n < 16 || n > 32 ||
839 #if defined(MBEDTLS_SSL_RENEGOTIATION)
840 ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
841 #endif
842 ssl->handshake->resume == 0 )
843 {
844 n = 0;
845 }
846
847 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
848 /*
849 * RFC 5077 section 3.4: "When presenting a ticket, the client MAY
850 * generate and include a Session ID in the TLS ClientHello."
851 */
852 #if defined(MBEDTLS_SSL_RENEGOTIATION)
853 if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
854 #endif
855 {
856 if( ssl->session_negotiate->ticket != NULL &&
857 ssl->session_negotiate->ticket_len != 0 )
858 {
859 ret = ssl->conf->f_rng( ssl->conf->p_rng, ssl->session_negotiate->id, 32 );
860
861 if( ret != 0 )
862 return( ret );
863
864 ssl->session_negotiate->id_len = n = 32;
865 }
866 }
867 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
868
869 *p++ = (unsigned char) n;
870
871 for( i = 0; i < n; i++ )
872 *p++ = ssl->session_negotiate->id[i];
873
874 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, session id len.: %d", n ) );
875 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 39, n );
876
877 /*
878 * DTLS cookie
879 */
880 #if defined(MBEDTLS_SSL_PROTO_DTLS)
881 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
882 {
883 if( ssl->handshake->verify_cookie == NULL )
884 {
885 MBEDTLS_SSL_DEBUG_MSG( 3, ( "no verify cookie to send" ) );
886 *p++ = 0;
887 }
888 else
889 {
890 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie",
891 ssl->handshake->verify_cookie,
892 ssl->handshake->verify_cookie_len );
893
894 *p++ = ssl->handshake->verify_cookie_len;
895 memcpy( p, ssl->handshake->verify_cookie,
896 ssl->handshake->verify_cookie_len );
897 p += ssl->handshake->verify_cookie_len;
898 }
899 }
900 #endif
901
902 /*
903 * Ciphersuite list
904 */
905 ciphersuites = ssl->conf->ciphersuite_list[ssl->minor_ver];
906
907 /* Skip writing ciphersuite length for now */
908 n = 0;
909 q = p;
910 p += 2;
911
912 for( i = 0; ciphersuites[i] != 0; i++ )
913 {
914 ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( ciphersuites[i] );
915
916 if( ssl_validate_ciphersuite( ciphersuite_info, ssl,
917 ssl->conf->min_minor_ver,
918 ssl->conf->max_minor_ver ) != 0 )
919 continue;
920
921 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %04x",
922 ciphersuites[i] ) );
923
924 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
925 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
926 uses_ec |= mbedtls_ssl_ciphersuite_uses_ec( ciphersuite_info );
927 #endif
928
929 n++;
930 *p++ = (unsigned char)( ciphersuites[i] >> 8 );
931 *p++ = (unsigned char)( ciphersuites[i] );
932 }
933
934 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, got %d ciphersuites (excluding SCSVs)", n ) );
935
936 /*
937 * Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV
938 */
939 #if defined(MBEDTLS_SSL_RENEGOTIATION)
940 if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
941 #endif
942 {
943 MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding EMPTY_RENEGOTIATION_INFO_SCSV" ) );
944 *p++ = (unsigned char)( MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO >> 8 );
945 *p++ = (unsigned char)( MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO );
946 n++;
947 }
948
949 /* Some versions of OpenSSL don't handle it correctly if not at end */
950 #if defined(MBEDTLS_SSL_FALLBACK_SCSV)
951 if( ssl->conf->fallback == MBEDTLS_SSL_IS_FALLBACK )
952 {
953 MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding FALLBACK_SCSV" ) );
954 *p++ = (unsigned char)( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 );
955 *p++ = (unsigned char)( MBEDTLS_SSL_FALLBACK_SCSV_VALUE );
956 n++;
957 }
958 #endif
959
960 *q++ = (unsigned char)( n >> 7 );
961 *q++ = (unsigned char)( n << 1 );
962
963 #if defined(MBEDTLS_ZLIB_SUPPORT)
964 offer_compress = 1;
965 #else
966 offer_compress = 0;
967 #endif
968
969 /*
970 * We don't support compression with DTLS right now: if many records come
971 * in the same datagram, uncompressing one could overwrite the next one.
972 * We don't want to add complexity for handling that case unless there is
973 * an actual need for it.
974 */
975 #if defined(MBEDTLS_SSL_PROTO_DTLS)
976 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
977 offer_compress = 0;
978 #endif
979
980 if( offer_compress )
981 {
982 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 2 ) );
983 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d %d",
984 MBEDTLS_SSL_COMPRESS_DEFLATE, MBEDTLS_SSL_COMPRESS_NULL ) );
985
986 *p++ = 2;
987 *p++ = MBEDTLS_SSL_COMPRESS_DEFLATE;
988 *p++ = MBEDTLS_SSL_COMPRESS_NULL;
989 }
990 else
991 {
992 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 1 ) );
993 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d",
994 MBEDTLS_SSL_COMPRESS_NULL ) );
995
996 *p++ = 1;
997 *p++ = MBEDTLS_SSL_COMPRESS_NULL;
998 }
999
1000 // First write extensions, then the total length
1001 //
1002 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
1003 ssl_write_hostname_ext( ssl, p + 2 + ext_len, &olen );
1004 ext_len += olen;
1005 #endif
1006
1007 /* Note that TLS_EMPTY_RENEGOTIATION_INFO_SCSV is always added
1008 * even if MBEDTLS_SSL_RENEGOTIATION is not defined. */
1009 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1010 ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen );
1011 ext_len += olen;
1012 #endif
1013
1014 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
1015 defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
1016 ssl_write_signature_algorithms_ext( ssl, p + 2 + ext_len, &olen );
1017 ext_len += olen;
1018 #endif
1019
1020 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
1021 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1022 if( uses_ec )
1023 {
1024 ssl_write_supported_elliptic_curves_ext( ssl, p + 2 + ext_len, &olen );
1025 ext_len += olen;
1026
1027 ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
1028 ext_len += olen;
1029 }
1030 #endif
1031
1032 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1033 ssl_write_ecjpake_kkpp_ext( ssl, p + 2 + ext_len, &olen );
1034 ext_len += olen;
1035 #endif
1036
1037 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
1038 ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen );
1039 ext_len += olen;
1040 #endif
1041
1042 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
1043 ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen );
1044 ext_len += olen;
1045 #endif
1046
1047 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
1048 ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len, &olen );
1049 ext_len += olen;
1050 #endif
1051
1052 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
1053 ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen );
1054 ext_len += olen;
1055 #endif
1056
1057 #if defined(MBEDTLS_SSL_ALPN)
1058 ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen );
1059 ext_len += olen;
1060 #endif
1061
1062 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
1063 ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
1064 ext_len += olen;
1065 #endif
1066
1067 /* olen unused if all extensions are disabled */
1068 ((void) olen);
1069
1070 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d",
1071 ext_len ) );
1072
1073 if( ext_len > 0 )
1074 {
1075 *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF );
1076 *p++ = (unsigned char)( ( ext_len ) & 0xFF );
1077 p += ext_len;
1078 }
1079
1080 ssl->out_msglen = p - buf;
1081 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
1082 ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_HELLO;
1083
1084 ssl->state++;
1085
1086 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1087 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1088 mbedtls_ssl_send_flight_completed( ssl );
1089 #endif
1090
1091 if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
1092 {
1093 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
1094 return( ret );
1095 }
1096
1097 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1098 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
1099 ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
1100 {
1101 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flight_transmit", ret );
1102 return( ret );
1103 }
1104 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1105
1106 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write client hello" ) );
1107
1108 return( 0 );
1109 }
1110
ssl_parse_renegotiation_info(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)1111 static int ssl_parse_renegotiation_info( mbedtls_ssl_context *ssl,
1112 const unsigned char *buf,
1113 size_t len )
1114 {
1115 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1116 if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
1117 {
1118 /* Check verify-data in constant-time. The length OTOH is no secret */
1119 if( len != 1 + ssl->verify_data_len * 2 ||
1120 buf[0] != ssl->verify_data_len * 2 ||
1121 mbedtls_ssl_safer_memcmp( buf + 1,
1122 ssl->own_verify_data, ssl->verify_data_len ) != 0 ||
1123 mbedtls_ssl_safer_memcmp( buf + 1 + ssl->verify_data_len,
1124 ssl->peer_verify_data, ssl->verify_data_len ) != 0 )
1125 {
1126 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
1127 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1128 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1129 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1130 }
1131 }
1132 else
1133 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1134 {
1135 if( len != 1 || buf[0] != 0x00 )
1136 {
1137 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
1138 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1139 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1140 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1141 }
1142
1143 ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
1144 }
1145
1146 return( 0 );
1147 }
1148
1149 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
ssl_parse_max_fragment_length_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)1150 static int ssl_parse_max_fragment_length_ext( mbedtls_ssl_context *ssl,
1151 const unsigned char *buf,
1152 size_t len )
1153 {
1154 /*
1155 * server should use the extension only if we did,
1156 * and if so the server's value should match ours (and len is always 1)
1157 */
1158 if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ||
1159 len != 1 ||
1160 buf[0] != ssl->conf->mfl_code )
1161 {
1162 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching max fragment length extension" ) );
1163 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1164 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1165 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1166 }
1167
1168 return( 0 );
1169 }
1170 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
1171
1172 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
ssl_parse_truncated_hmac_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)1173 static int ssl_parse_truncated_hmac_ext( mbedtls_ssl_context *ssl,
1174 const unsigned char *buf,
1175 size_t len )
1176 {
1177 if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED ||
1178 len != 0 )
1179 {
1180 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching truncated HMAC extension" ) );
1181 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1182 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1183 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1184 }
1185
1186 ((void) buf);
1187
1188 ssl->session_negotiate->trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_ENABLED;
1189
1190 return( 0 );
1191 }
1192 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
1193
1194 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
ssl_parse_encrypt_then_mac_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)1195 static int ssl_parse_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
1196 const unsigned char *buf,
1197 size_t len )
1198 {
1199 if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
1200 ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ||
1201 len != 0 )
1202 {
1203 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching encrypt-then-MAC extension" ) );
1204 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1205 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1206 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1207 }
1208
1209 ((void) buf);
1210
1211 ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED;
1212
1213 return( 0 );
1214 }
1215 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
1216
1217 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
ssl_parse_extended_ms_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)1218 static int ssl_parse_extended_ms_ext( mbedtls_ssl_context *ssl,
1219 const unsigned char *buf,
1220 size_t len )
1221 {
1222 if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
1223 ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ||
1224 len != 0 )
1225 {
1226 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching extended master secret extension" ) );
1227 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1228 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1229 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1230 }
1231
1232 ((void) buf);
1233
1234 ssl->handshake->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED;
1235
1236 return( 0 );
1237 }
1238 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
1239
1240 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
ssl_parse_session_ticket_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)1241 static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
1242 const unsigned char *buf,
1243 size_t len )
1244 {
1245 if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED ||
1246 len != 0 )
1247 {
1248 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching session ticket extension" ) );
1249 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1250 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1251 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1252 }
1253
1254 ((void) buf);
1255
1256 ssl->handshake->new_session_ticket = 1;
1257
1258 return( 0 );
1259 }
1260 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
1261
1262 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
1263 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl_parse_supported_point_formats_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)1264 static int ssl_parse_supported_point_formats_ext( mbedtls_ssl_context *ssl,
1265 const unsigned char *buf,
1266 size_t len )
1267 {
1268 size_t list_size;
1269 const unsigned char *p;
1270
1271 if( len == 0 || (size_t)( buf[0] + 1 ) != len )
1272 {
1273 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1274 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1275 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1276 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1277 }
1278 list_size = buf[0];
1279
1280 p = buf + 1;
1281 while( list_size > 0 )
1282 {
1283 if( p[0] == MBEDTLS_ECP_PF_UNCOMPRESSED ||
1284 p[0] == MBEDTLS_ECP_PF_COMPRESSED )
1285 {
1286 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
1287 ssl->handshake->ecdh_ctx.point_format = p[0];
1288 #endif
1289 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1290 ssl->handshake->ecjpake_ctx.point_format = p[0];
1291 #endif
1292 MBEDTLS_SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) );
1293 return( 0 );
1294 }
1295
1296 list_size--;
1297 p++;
1298 }
1299
1300 MBEDTLS_SSL_DEBUG_MSG( 1, ( "no point format in common" ) );
1301 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1302 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1303 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1304 }
1305 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
1306 MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1307
1308 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl_parse_ecjpake_kkpp(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)1309 static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl,
1310 const unsigned char *buf,
1311 size_t len )
1312 {
1313 int ret;
1314
1315 if( ssl->transform_negotiate->ciphersuite_info->key_exchange !=
1316 MBEDTLS_KEY_EXCHANGE_ECJPAKE )
1317 {
1318 MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip ecjpake kkpp extension" ) );
1319 return( 0 );
1320 }
1321
1322 /* If we got here, we no longer need our cached extension */
1323 mbedtls_free( ssl->handshake->ecjpake_cache );
1324 ssl->handshake->ecjpake_cache = NULL;
1325 ssl->handshake->ecjpake_cache_len = 0;
1326
1327 if( ( ret = mbedtls_ecjpake_read_round_one( &ssl->handshake->ecjpake_ctx,
1328 buf, len ) ) != 0 )
1329 {
1330 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_one", ret );
1331 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1332 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1333 return( ret );
1334 }
1335
1336 return( 0 );
1337 }
1338 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1339
1340 #if defined(MBEDTLS_SSL_ALPN)
ssl_parse_alpn_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)1341 static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl,
1342 const unsigned char *buf, size_t len )
1343 {
1344 size_t list_len, name_len;
1345 const char **p;
1346
1347 /* If we didn't send it, the server shouldn't send it */
1348 if( ssl->conf->alpn_list == NULL )
1349 {
1350 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching ALPN extension" ) );
1351 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1352 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1353 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1354 }
1355
1356 /*
1357 * opaque ProtocolName<1..2^8-1>;
1358 *
1359 * struct {
1360 * ProtocolName protocol_name_list<2..2^16-1>
1361 * } ProtocolNameList;
1362 *
1363 * the "ProtocolNameList" MUST contain exactly one "ProtocolName"
1364 */
1365
1366 /* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */
1367 if( len < 4 )
1368 {
1369 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1370 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1371 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1372 }
1373
1374 list_len = ( buf[0] << 8 ) | buf[1];
1375 if( list_len != len - 2 )
1376 {
1377 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1378 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1379 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1380 }
1381
1382 name_len = buf[2];
1383 if( name_len != list_len - 1 )
1384 {
1385 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1386 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1387 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1388 }
1389
1390 /* Check that the server chosen protocol was in our list and save it */
1391 for( p = ssl->conf->alpn_list; *p != NULL; p++ )
1392 {
1393 if( name_len == strlen( *p ) &&
1394 memcmp( buf + 3, *p, name_len ) == 0 )
1395 {
1396 ssl->alpn_chosen = *p;
1397 return( 0 );
1398 }
1399 }
1400
1401 MBEDTLS_SSL_DEBUG_MSG( 1, ( "ALPN extension: no matching protocol" ) );
1402 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1403 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1404 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1405 }
1406 #endif /* MBEDTLS_SSL_ALPN */
1407
1408 /*
1409 * Parse HelloVerifyRequest. Only called after verifying the HS type.
1410 */
1411 #if defined(MBEDTLS_SSL_PROTO_DTLS)
ssl_parse_hello_verify_request(mbedtls_ssl_context * ssl)1412 static int ssl_parse_hello_verify_request( mbedtls_ssl_context *ssl )
1413 {
1414 const unsigned char *p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
1415 int major_ver, minor_ver;
1416 unsigned char cookie_len;
1417
1418 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse hello verify request" ) );
1419
1420 /*
1421 * struct {
1422 * ProtocolVersion server_version;
1423 * opaque cookie<0..2^8-1>;
1424 * } HelloVerifyRequest;
1425 */
1426 MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
1427 mbedtls_ssl_read_version( &major_ver, &minor_ver, ssl->conf->transport, p );
1428 p += 2;
1429
1430 /*
1431 * Since the RFC is not clear on this point, accept DTLS 1.0 (TLS 1.1)
1432 * even is lower than our min version.
1433 */
1434 if( major_ver < MBEDTLS_SSL_MAJOR_VERSION_3 ||
1435 minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 ||
1436 major_ver > ssl->conf->max_major_ver ||
1437 minor_ver > ssl->conf->max_minor_ver )
1438 {
1439 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server version" ) );
1440
1441 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1442 MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
1443
1444 return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
1445 }
1446
1447 cookie_len = *p++;
1448 MBEDTLS_SSL_DEBUG_BUF( 3, "cookie", p, cookie_len );
1449
1450 if( ( ssl->in_msg + ssl->in_msglen ) - p < cookie_len )
1451 {
1452 MBEDTLS_SSL_DEBUG_MSG( 1,
1453 ( "cookie length does not match incoming message size" ) );
1454 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1455 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1456 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1457 }
1458
1459 mbedtls_free( ssl->handshake->verify_cookie );
1460
1461 ssl->handshake->verify_cookie = mbedtls_calloc( 1, cookie_len );
1462 if( ssl->handshake->verify_cookie == NULL )
1463 {
1464 MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc failed (%d bytes)", cookie_len ) );
1465 return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
1466 }
1467
1468 memcpy( ssl->handshake->verify_cookie, p, cookie_len );
1469 ssl->handshake->verify_cookie_len = cookie_len;
1470
1471 /* Start over at ClientHello */
1472 ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
1473 mbedtls_ssl_reset_checksum( ssl );
1474
1475 mbedtls_ssl_recv_flight_completed( ssl );
1476
1477 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse hello verify request" ) );
1478
1479 return( 0 );
1480 }
1481 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1482
ssl_parse_server_hello(mbedtls_ssl_context * ssl)1483 static int ssl_parse_server_hello( mbedtls_ssl_context *ssl )
1484 {
1485 int ret, i;
1486 size_t n;
1487 size_t ext_len;
1488 unsigned char *buf, *ext;
1489 unsigned char comp;
1490 #if defined(MBEDTLS_ZLIB_SUPPORT)
1491 int accept_comp;
1492 #endif
1493 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1494 int renegotiation_info_seen = 0;
1495 #endif
1496 int handshake_failure = 0;
1497 const mbedtls_ssl_ciphersuite_t *suite_info;
1498
1499 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello" ) );
1500
1501 buf = ssl->in_msg;
1502
1503 if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
1504 {
1505 /* No alert on a read error. */
1506 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
1507 return( ret );
1508 }
1509
1510 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
1511 {
1512 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1513 if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
1514 {
1515 ssl->renego_records_seen++;
1516
1517 if( ssl->conf->renego_max_records >= 0 &&
1518 ssl->renego_records_seen > ssl->conf->renego_max_records )
1519 {
1520 MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation requested, "
1521 "but not honored by server" ) );
1522 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
1523 }
1524
1525 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-handshake message during renego" ) );
1526
1527 ssl->keep_current_message = 1;
1528 return( MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO );
1529 }
1530 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1531
1532 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1533 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1534 MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
1535 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
1536 }
1537
1538 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1539 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1540 {
1541 if( buf[0] == MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST )
1542 {
1543 MBEDTLS_SSL_DEBUG_MSG( 2, ( "received hello verify request" ) );
1544 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
1545 return( ssl_parse_hello_verify_request( ssl ) );
1546 }
1547 else
1548 {
1549 /* We made it through the verification process */
1550 mbedtls_free( ssl->handshake->verify_cookie );
1551 ssl->handshake->verify_cookie = NULL;
1552 ssl->handshake->verify_cookie_len = 0;
1553 }
1554 }
1555 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1556
1557 if( ssl->in_hslen < 38 + mbedtls_ssl_hs_hdr_len( ssl ) ||
1558 buf[0] != MBEDTLS_SSL_HS_SERVER_HELLO )
1559 {
1560 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1561 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1562 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1563 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1564 }
1565
1566 /*
1567 * 0 . 1 server_version
1568 * 2 . 33 random (maybe including 4 bytes of Unix time)
1569 * 34 . 34 session_id length = n
1570 * 35 . 34+n session_id
1571 * 35+n . 36+n cipher_suite
1572 * 37+n . 37+n compression_method
1573 *
1574 * 38+n . 39+n extensions length (optional)
1575 * 40+n . .. extensions
1576 */
1577 buf += mbedtls_ssl_hs_hdr_len( ssl );
1578
1579 MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, version", buf + 0, 2 );
1580 mbedtls_ssl_read_version( &ssl->major_ver, &ssl->minor_ver,
1581 ssl->conf->transport, buf + 0 );
1582
1583 if( ssl->major_ver < ssl->conf->min_major_ver ||
1584 ssl->minor_ver < ssl->conf->min_minor_ver ||
1585 ssl->major_ver > ssl->conf->max_major_ver ||
1586 ssl->minor_ver > ssl->conf->max_minor_ver )
1587 {
1588 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server version out of bounds - "
1589 " min: [%d:%d], server: [%d:%d], max: [%d:%d]",
1590 ssl->conf->min_major_ver, ssl->conf->min_minor_ver,
1591 ssl->major_ver, ssl->minor_ver,
1592 ssl->conf->max_major_ver, ssl->conf->max_minor_ver ) );
1593
1594 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1595 MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
1596
1597 return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
1598 }
1599
1600 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu",
1601 ( (uint32_t) buf[2] << 24 ) |
1602 ( (uint32_t) buf[3] << 16 ) |
1603 ( (uint32_t) buf[4] << 8 ) |
1604 ( (uint32_t) buf[5] ) ) );
1605
1606 memcpy( ssl->handshake->randbytes + 32, buf + 2, 32 );
1607
1608 n = buf[34];
1609
1610 MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 2, 32 );
1611
1612 if( n > 32 )
1613 {
1614 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1615 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1616 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1617 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1618 }
1619
1620 if( ssl->in_hslen > mbedtls_ssl_hs_hdr_len( ssl ) + 39 + n )
1621 {
1622 ext_len = ( ( buf[38 + n] << 8 )
1623 | ( buf[39 + n] ) );
1624
1625 if( ( ext_len > 0 && ext_len < 4 ) ||
1626 ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + 40 + n + ext_len )
1627 {
1628 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1629 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1630 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1631 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1632 }
1633 }
1634 else if( ssl->in_hslen == mbedtls_ssl_hs_hdr_len( ssl ) + 38 + n )
1635 {
1636 ext_len = 0;
1637 }
1638 else
1639 {
1640 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1641 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1642 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1643 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1644 }
1645
1646 /* ciphersuite (used later) */
1647 i = ( buf[35 + n] << 8 ) | buf[36 + n];
1648
1649 /*
1650 * Read and check compression
1651 */
1652 comp = buf[37 + n];
1653
1654 #if defined(MBEDTLS_ZLIB_SUPPORT)
1655 /* See comments in ssl_write_client_hello() */
1656 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1657 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1658 accept_comp = 0;
1659 else
1660 #endif
1661 accept_comp = 1;
1662
1663 if( comp != MBEDTLS_SSL_COMPRESS_NULL &&
1664 ( comp != MBEDTLS_SSL_COMPRESS_DEFLATE || accept_comp == 0 ) )
1665 #else /* MBEDTLS_ZLIB_SUPPORT */
1666 if( comp != MBEDTLS_SSL_COMPRESS_NULL )
1667 #endif/* MBEDTLS_ZLIB_SUPPORT */
1668 {
1669 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server hello, bad compression: %d", comp ) );
1670 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1671 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
1672 return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
1673 }
1674
1675 /*
1676 * Initialize update checksum functions
1677 */
1678 ssl->transform_negotiate->ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( i );
1679
1680 if( ssl->transform_negotiate->ciphersuite_info == NULL )
1681 {
1682 MBEDTLS_SSL_DEBUG_MSG( 1, ( "ciphersuite info for %04x not found", i ) );
1683 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1684 MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
1685 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
1686 }
1687
1688 mbedtls_ssl_optimize_checksum( ssl, ssl->transform_negotiate->ciphersuite_info );
1689
1690 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
1691 MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, session id", buf + 35, n );
1692
1693 /*
1694 * Check if the session can be resumed
1695 */
1696 if( ssl->handshake->resume == 0 || n == 0 ||
1697 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1698 ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
1699 #endif
1700 ssl->session_negotiate->ciphersuite != i ||
1701 ssl->session_negotiate->compression != comp ||
1702 ssl->session_negotiate->id_len != n ||
1703 memcmp( ssl->session_negotiate->id, buf + 35, n ) != 0 )
1704 {
1705 ssl->state++;
1706 ssl->handshake->resume = 0;
1707 #if defined(MBEDTLS_HAVE_TIME)
1708 ssl->session_negotiate->start = mbedtls_time( NULL );
1709 #endif
1710 ssl->session_negotiate->ciphersuite = i;
1711 ssl->session_negotiate->compression = comp;
1712 ssl->session_negotiate->id_len = n;
1713 memcpy( ssl->session_negotiate->id, buf + 35, n );
1714 }
1715 else
1716 {
1717 ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
1718
1719 if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
1720 {
1721 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
1722 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1723 MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
1724 return( ret );
1725 }
1726 }
1727
1728 MBEDTLS_SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
1729 ssl->handshake->resume ? "a" : "no" ) );
1730
1731 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %04x", i ) );
1732 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", buf[37 + n] ) );
1733
1734 /*
1735 * Perform cipher suite validation in same way as in ssl_write_client_hello.
1736 */
1737 i = 0;
1738 while( 1 )
1739 {
1740 if( ssl->conf->ciphersuite_list[ssl->minor_ver][i] == 0 )
1741 {
1742 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1743 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1744 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
1745 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1746 }
1747
1748 if( ssl->conf->ciphersuite_list[ssl->minor_ver][i++] ==
1749 ssl->session_negotiate->ciphersuite )
1750 {
1751 break;
1752 }
1753 }
1754
1755 suite_info = mbedtls_ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite );
1756 if( ssl_validate_ciphersuite( suite_info, ssl, ssl->minor_ver, ssl->minor_ver ) != 0 )
1757 {
1758 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1759 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1760 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
1761 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1762 }
1763
1764 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %s", suite_info->name ) );
1765
1766 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
1767 if( suite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA &&
1768 ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
1769 {
1770 ssl->handshake->ecrs_enabled = 1;
1771 }
1772 #endif
1773
1774 if( comp != MBEDTLS_SSL_COMPRESS_NULL
1775 #if defined(MBEDTLS_ZLIB_SUPPORT)
1776 && comp != MBEDTLS_SSL_COMPRESS_DEFLATE
1777 #endif
1778 )
1779 {
1780 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1781 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1782 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
1783 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1784 }
1785 ssl->session_negotiate->compression = comp;
1786
1787 ext = buf + 40 + n;
1788
1789 MBEDTLS_SSL_DEBUG_MSG( 2, ( "server hello, total extension length: %d", ext_len ) );
1790
1791 while( ext_len )
1792 {
1793 unsigned int ext_id = ( ( ext[0] << 8 )
1794 | ( ext[1] ) );
1795 unsigned int ext_size = ( ( ext[2] << 8 )
1796 | ( ext[3] ) );
1797
1798 if( ext_size + 4 > ext_len )
1799 {
1800 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1801 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1802 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1803 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1804 }
1805
1806 switch( ext_id )
1807 {
1808 case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO:
1809 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
1810 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1811 renegotiation_info_seen = 1;
1812 #endif
1813
1814 if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4,
1815 ext_size ) ) != 0 )
1816 return( ret );
1817
1818 break;
1819
1820 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
1821 case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH:
1822 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found max_fragment_length extension" ) );
1823
1824 if( ( ret = ssl_parse_max_fragment_length_ext( ssl,
1825 ext + 4, ext_size ) ) != 0 )
1826 {
1827 return( ret );
1828 }
1829
1830 break;
1831 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
1832
1833 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
1834 case MBEDTLS_TLS_EXT_TRUNCATED_HMAC:
1835 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found truncated_hmac extension" ) );
1836
1837 if( ( ret = ssl_parse_truncated_hmac_ext( ssl,
1838 ext + 4, ext_size ) ) != 0 )
1839 {
1840 return( ret );
1841 }
1842
1843 break;
1844 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
1845
1846 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
1847 case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
1848 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt_then_mac extension" ) );
1849
1850 if( ( ret = ssl_parse_encrypt_then_mac_ext( ssl,
1851 ext + 4, ext_size ) ) != 0 )
1852 {
1853 return( ret );
1854 }
1855
1856 break;
1857 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
1858
1859 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
1860 case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET:
1861 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extended_master_secret extension" ) );
1862
1863 if( ( ret = ssl_parse_extended_ms_ext( ssl,
1864 ext + 4, ext_size ) ) != 0 )
1865 {
1866 return( ret );
1867 }
1868
1869 break;
1870 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
1871
1872 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
1873 case MBEDTLS_TLS_EXT_SESSION_TICKET:
1874 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found session_ticket extension" ) );
1875
1876 if( ( ret = ssl_parse_session_ticket_ext( ssl,
1877 ext + 4, ext_size ) ) != 0 )
1878 {
1879 return( ret );
1880 }
1881
1882 break;
1883 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
1884
1885 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
1886 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1887 case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS:
1888 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported_point_formats extension" ) );
1889
1890 if( ( ret = ssl_parse_supported_point_formats_ext( ssl,
1891 ext + 4, ext_size ) ) != 0 )
1892 {
1893 return( ret );
1894 }
1895
1896 break;
1897 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
1898 MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1899
1900 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1901 case MBEDTLS_TLS_EXT_ECJPAKE_KKPP:
1902 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ecjpake_kkpp extension" ) );
1903
1904 if( ( ret = ssl_parse_ecjpake_kkpp( ssl,
1905 ext + 4, ext_size ) ) != 0 )
1906 {
1907 return( ret );
1908 }
1909
1910 break;
1911 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1912
1913 #if defined(MBEDTLS_SSL_ALPN)
1914 case MBEDTLS_TLS_EXT_ALPN:
1915 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
1916
1917 if( ( ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size ) ) != 0 )
1918 return( ret );
1919
1920 break;
1921 #endif /* MBEDTLS_SSL_ALPN */
1922
1923 default:
1924 MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)",
1925 ext_id ) );
1926 }
1927
1928 ext_len -= 4 + ext_size;
1929 ext += 4 + ext_size;
1930
1931 if( ext_len > 0 && ext_len < 4 )
1932 {
1933 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
1934 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1935 }
1936 }
1937
1938 /*
1939 * Renegotiation security checks
1940 */
1941 if( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
1942 ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE )
1943 {
1944 MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
1945 handshake_failure = 1;
1946 }
1947 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1948 else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
1949 ssl->secure_renegotiation == MBEDTLS_SSL_SECURE_RENEGOTIATION &&
1950 renegotiation_info_seen == 0 )
1951 {
1952 MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) );
1953 handshake_failure = 1;
1954 }
1955 else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
1956 ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
1957 ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION )
1958 {
1959 MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) );
1960 handshake_failure = 1;
1961 }
1962 else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
1963 ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
1964 renegotiation_info_seen == 1 )
1965 {
1966 MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
1967 handshake_failure = 1;
1968 }
1969 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1970
1971 if( handshake_failure == 1 )
1972 {
1973 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1974 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1975 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
1976 }
1977
1978 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
1979
1980 return( 0 );
1981 }
1982
1983 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
1984 defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
ssl_parse_server_dh_params(mbedtls_ssl_context * ssl,unsigned char ** p,unsigned char * end)1985 static int ssl_parse_server_dh_params( mbedtls_ssl_context *ssl, unsigned char **p,
1986 unsigned char *end )
1987 {
1988 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
1989
1990 /*
1991 * Ephemeral DH parameters:
1992 *
1993 * struct {
1994 * opaque dh_p<1..2^16-1>;
1995 * opaque dh_g<1..2^16-1>;
1996 * opaque dh_Ys<1..2^16-1>;
1997 * } ServerDHParams;
1998 */
1999 if( ( ret = mbedtls_dhm_read_params( &ssl->handshake->dhm_ctx, p, end ) ) != 0 )
2000 {
2001 MBEDTLS_SSL_DEBUG_RET( 2, ( "mbedtls_dhm_read_params" ), ret );
2002 return( ret );
2003 }
2004
2005 if( ssl->handshake->dhm_ctx.len * 8 < ssl->conf->dhm_min_bitlen )
2006 {
2007 MBEDTLS_SSL_DEBUG_MSG( 1, ( "DHM prime too short: %d < %d",
2008 ssl->handshake->dhm_ctx.len * 8,
2009 ssl->conf->dhm_min_bitlen ) );
2010 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2011 }
2012
2013 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P );
2014 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G );
2015 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
2016
2017 return( ret );
2018 }
2019 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
2020 MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
2021
2022 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
2023 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
2024 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
2025 defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
2026 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
ssl_check_server_ecdh_params(const mbedtls_ssl_context * ssl)2027 static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl )
2028 {
2029 const mbedtls_ecp_curve_info *curve_info;
2030 mbedtls_ecp_group_id grp_id;
2031 #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
2032 grp_id = ssl->handshake->ecdh_ctx.grp.id;
2033 #else
2034 grp_id = ssl->handshake->ecdh_ctx.grp_id;
2035 #endif
2036
2037 curve_info = mbedtls_ecp_curve_info_from_grp_id( grp_id );
2038 if( curve_info == NULL )
2039 {
2040 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2041 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2042 }
2043
2044 MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) );
2045
2046 #if defined(MBEDTLS_ECP_C)
2047 if( mbedtls_ssl_check_curve( ssl, grp_id ) != 0 )
2048 #else
2049 if( ssl->handshake->ecdh_ctx.grp.nbits < 163 ||
2050 ssl->handshake->ecdh_ctx.grp.nbits > 521 )
2051 #endif
2052 return( -1 );
2053
2054 MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
2055 MBEDTLS_DEBUG_ECDH_QP );
2056
2057 return( 0 );
2058 }
2059 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
2060 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
2061 MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
2062 MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
2063 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
2064
2065 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
2066 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
2067 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
ssl_parse_server_ecdh_params(mbedtls_ssl_context * ssl,unsigned char ** p,unsigned char * end)2068 static int ssl_parse_server_ecdh_params( mbedtls_ssl_context *ssl,
2069 unsigned char **p,
2070 unsigned char *end )
2071 {
2072 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
2073
2074 /*
2075 * Ephemeral ECDH parameters:
2076 *
2077 * struct {
2078 * ECParameters curve_params;
2079 * ECPoint public;
2080 * } ServerECDHParams;
2081 */
2082 if( ( ret = mbedtls_ecdh_read_params( &ssl->handshake->ecdh_ctx,
2083 (const unsigned char **) p, end ) ) != 0 )
2084 {
2085 MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_read_params" ), ret );
2086 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2087 if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2088 ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
2089 #endif
2090 return( ret );
2091 }
2092
2093 if( ssl_check_server_ecdh_params( ssl ) != 0 )
2094 {
2095 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message (ECDHE curve)" ) );
2096 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2097 }
2098
2099 return( ret );
2100 }
2101 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
2102 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
2103 MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
2104
2105 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
ssl_parse_server_psk_hint(mbedtls_ssl_context * ssl,unsigned char ** p,unsigned char * end)2106 static int ssl_parse_server_psk_hint( mbedtls_ssl_context *ssl,
2107 unsigned char **p,
2108 unsigned char *end )
2109 {
2110 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
2111 size_t len;
2112 ((void) ssl);
2113
2114 /*
2115 * PSK parameters:
2116 *
2117 * opaque psk_identity_hint<0..2^16-1>;
2118 */
2119 if( end - (*p) < 2 )
2120 {
2121 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message "
2122 "(psk_identity_hint length)" ) );
2123 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2124 }
2125 len = (*p)[0] << 8 | (*p)[1];
2126 *p += 2;
2127
2128 if( end - (*p) < (int) len )
2129 {
2130 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message "
2131 "(psk_identity_hint length)" ) );
2132 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2133 }
2134
2135 /*
2136 * Note: we currently ignore the PKS identity hint, as we only allow one
2137 * PSK to be provisionned on the client. This could be changed later if
2138 * someone needs that feature.
2139 */
2140 *p += len;
2141 ret = 0;
2142
2143 return( ret );
2144 }
2145 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
2146
2147 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
2148 defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
2149 /*
2150 * Generate a pre-master secret and encrypt it with the server's RSA key
2151 */
ssl_write_encrypted_pms(mbedtls_ssl_context * ssl,size_t offset,size_t * olen,size_t pms_offset)2152 static int ssl_write_encrypted_pms( mbedtls_ssl_context *ssl,
2153 size_t offset, size_t *olen,
2154 size_t pms_offset )
2155 {
2156 int ret;
2157 size_t len_bytes = ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 ? 0 : 2;
2158 unsigned char *p = ssl->handshake->premaster + pms_offset;
2159
2160 if( offset + len_bytes > MBEDTLS_SSL_OUT_CONTENT_LEN )
2161 {
2162 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small for encrypted pms" ) );
2163 return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
2164 }
2165
2166 /*
2167 * Generate (part of) the pre-master as
2168 * struct {
2169 * ProtocolVersion client_version;
2170 * opaque random[46];
2171 * } PreMasterSecret;
2172 */
2173 mbedtls_ssl_write_version( ssl->conf->max_major_ver, ssl->conf->max_minor_ver,
2174 ssl->conf->transport, p );
2175
2176 if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p + 2, 46 ) ) != 0 )
2177 {
2178 MBEDTLS_SSL_DEBUG_RET( 1, "f_rng", ret );
2179 return( ret );
2180 }
2181
2182 ssl->handshake->pmslen = 48;
2183
2184 if( ssl->session_negotiate->peer_cert == NULL )
2185 {
2186 MBEDTLS_SSL_DEBUG_MSG( 2, ( "certificate required" ) );
2187 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2188 }
2189
2190 /*
2191 * Now write it out, encrypted
2192 */
2193 if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk,
2194 MBEDTLS_PK_RSA ) )
2195 {
2196 MBEDTLS_SSL_DEBUG_MSG( 1, ( "certificate key type mismatch" ) );
2197 return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
2198 }
2199
2200 if( ( ret = mbedtls_pk_encrypt( &ssl->session_negotiate->peer_cert->pk,
2201 p, ssl->handshake->pmslen,
2202 ssl->out_msg + offset + len_bytes, olen,
2203 MBEDTLS_SSL_OUT_CONTENT_LEN - offset - len_bytes,
2204 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
2205 {
2206 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_rsa_pkcs1_encrypt", ret );
2207 return( ret );
2208 }
2209
2210 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
2211 defined(MBEDTLS_SSL_PROTO_TLS1_2)
2212 if( len_bytes == 2 )
2213 {
2214 ssl->out_msg[offset+0] = (unsigned char)( *olen >> 8 );
2215 ssl->out_msg[offset+1] = (unsigned char)( *olen );
2216 *olen += 2;
2217 }
2218 #endif
2219
2220 return( 0 );
2221 }
2222 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED ||
2223 MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
2224
2225 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
2226 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
2227 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
2228 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
ssl_parse_signature_algorithm(mbedtls_ssl_context * ssl,unsigned char ** p,unsigned char * end,mbedtls_md_type_t * md_alg,mbedtls_pk_type_t * pk_alg)2229 static int ssl_parse_signature_algorithm( mbedtls_ssl_context *ssl,
2230 unsigned char **p,
2231 unsigned char *end,
2232 mbedtls_md_type_t *md_alg,
2233 mbedtls_pk_type_t *pk_alg )
2234 {
2235 ((void) ssl);
2236 *md_alg = MBEDTLS_MD_NONE;
2237 *pk_alg = MBEDTLS_PK_NONE;
2238
2239 /* Only in TLS 1.2 */
2240 if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
2241 {
2242 return( 0 );
2243 }
2244
2245 if( (*p) + 2 > end )
2246 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2247
2248 /*
2249 * Get hash algorithm
2250 */
2251 if( ( *md_alg = mbedtls_ssl_md_alg_from_hash( (*p)[0] ) ) == MBEDTLS_MD_NONE )
2252 {
2253 MBEDTLS_SSL_DEBUG_MSG( 1, ( "Server used unsupported "
2254 "HashAlgorithm %d", *(p)[0] ) );
2255 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2256 }
2257
2258 /*
2259 * Get signature algorithm
2260 */
2261 if( ( *pk_alg = mbedtls_ssl_pk_alg_from_sig( (*p)[1] ) ) == MBEDTLS_PK_NONE )
2262 {
2263 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used unsupported "
2264 "SignatureAlgorithm %d", (*p)[1] ) );
2265 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2266 }
2267
2268 /*
2269 * Check if the hash is acceptable
2270 */
2271 if( mbedtls_ssl_check_sig_hash( ssl, *md_alg ) != 0 )
2272 {
2273 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used HashAlgorithm %d that was not offered",
2274 *(p)[0] ) );
2275 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2276 }
2277
2278 MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used SignatureAlgorithm %d", (*p)[1] ) );
2279 MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used HashAlgorithm %d", (*p)[0] ) );
2280 *p += 2;
2281
2282 return( 0 );
2283 }
2284 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
2285 MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
2286 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
2287 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
2288
2289 #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
2290 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
ssl_get_ecdh_params_from_cert(mbedtls_ssl_context * ssl)2291 static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
2292 {
2293 int ret;
2294 const mbedtls_ecp_keypair *peer_key;
2295
2296 if( ssl->session_negotiate->peer_cert == NULL )
2297 {
2298 MBEDTLS_SSL_DEBUG_MSG( 2, ( "certificate required" ) );
2299 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2300 }
2301
2302 if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk,
2303 MBEDTLS_PK_ECKEY ) )
2304 {
2305 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
2306 return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
2307 }
2308
2309 peer_key = mbedtls_pk_ec( ssl->session_negotiate->peer_cert->pk );
2310
2311 if( ( ret = mbedtls_ecdh_get_params( &ssl->handshake->ecdh_ctx, peer_key,
2312 MBEDTLS_ECDH_THEIRS ) ) != 0 )
2313 {
2314 MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_get_params" ), ret );
2315 return( ret );
2316 }
2317
2318 if( ssl_check_server_ecdh_params( ssl ) != 0 )
2319 {
2320 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server certificate (ECDH curve)" ) );
2321 return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE );
2322 }
2323
2324 return( ret );
2325 }
2326 #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
2327 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
2328
ssl_parse_server_key_exchange(mbedtls_ssl_context * ssl)2329 static int ssl_parse_server_key_exchange( mbedtls_ssl_context *ssl )
2330 {
2331 int ret;
2332 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
2333 ssl->transform_negotiate->ciphersuite_info;
2334 unsigned char *p = NULL, *end = NULL;
2335
2336 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server key exchange" ) );
2337
2338 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
2339 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA )
2340 {
2341 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
2342 ssl->state++;
2343 return( 0 );
2344 }
2345 ((void) p);
2346 ((void) end);
2347 #endif
2348
2349 #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
2350 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
2351 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
2352 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
2353 {
2354 if( ( ret = ssl_get_ecdh_params_from_cert( ssl ) ) != 0 )
2355 {
2356 MBEDTLS_SSL_DEBUG_RET( 1, "ssl_get_ecdh_params_from_cert", ret );
2357 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2358 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
2359 return( ret );
2360 }
2361
2362 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
2363 ssl->state++;
2364 return( 0 );
2365 }
2366 ((void) p);
2367 ((void) end);
2368 #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
2369 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
2370
2371 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2372 if( ssl->handshake->ecrs_enabled &&
2373 ssl->handshake->ecrs_state == ssl_ecrs_ske_start_processing )
2374 {
2375 goto start_processing;
2376 }
2377 #endif
2378
2379 if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
2380 {
2381 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
2382 return( ret );
2383 }
2384
2385 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
2386 {
2387 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2388 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2389 MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
2390 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2391 }
2392
2393 /*
2394 * ServerKeyExchange may be skipped with PSK and RSA-PSK when the server
2395 * doesn't use a psk_identity_hint
2396 */
2397 if( ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE )
2398 {
2399 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
2400 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
2401 {
2402 /* Current message is probably either
2403 * CertificateRequest or ServerHelloDone */
2404 ssl->keep_current_message = 1;
2405 goto exit;
2406 }
2407
2408 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key exchange message must "
2409 "not be skipped" ) );
2410 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2411 MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
2412
2413 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2414 }
2415
2416 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2417 if( ssl->handshake->ecrs_enabled )
2418 ssl->handshake->ecrs_state = ssl_ecrs_ske_start_processing;
2419
2420 start_processing:
2421 #endif
2422 p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
2423 end = ssl->in_msg + ssl->in_hslen;
2424 MBEDTLS_SSL_DEBUG_BUF( 3, "server key exchange", p, end - p );
2425
2426 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
2427 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
2428 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
2429 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
2430 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
2431 {
2432 if( ssl_parse_server_psk_hint( ssl, &p, end ) != 0 )
2433 {
2434 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2435 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2436 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
2437 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2438 }
2439 } /* FALLTROUGH */
2440 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
2441
2442 #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) || \
2443 defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
2444 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
2445 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
2446 ; /* nothing more to do */
2447 else
2448 #endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED ||
2449 MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
2450 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
2451 defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
2452 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA ||
2453 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK )
2454 {
2455 if( ssl_parse_server_dh_params( ssl, &p, end ) != 0 )
2456 {
2457 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2458 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2459 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
2460 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2461 }
2462 }
2463 else
2464 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
2465 MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
2466 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
2467 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
2468 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
2469 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
2470 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
2471 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
2472 {
2473 if( ssl_parse_server_ecdh_params( ssl, &p, end ) != 0 )
2474 {
2475 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2476 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2477 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
2478 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2479 }
2480 }
2481 else
2482 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
2483 MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
2484 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
2485 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
2486 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
2487 {
2488 ret = mbedtls_ecjpake_read_round_two( &ssl->handshake->ecjpake_ctx,
2489 p, end - p );
2490 if( ret != 0 )
2491 {
2492 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_two", ret );
2493 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2494 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
2495 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2496 }
2497 }
2498 else
2499 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
2500 {
2501 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2502 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2503 }
2504
2505 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)
2506 if( mbedtls_ssl_ciphersuite_uses_server_signature( ciphersuite_info ) )
2507 {
2508 size_t sig_len, hashlen;
2509 unsigned char hash[64];
2510 mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE;
2511 mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
2512 unsigned char *params = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
2513 size_t params_len = p - params;
2514 void *rs_ctx = NULL;
2515
2516 /*
2517 * Handle the digitally-signed structure
2518 */
2519 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
2520 if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
2521 {
2522 if( ssl_parse_signature_algorithm( ssl, &p, end,
2523 &md_alg, &pk_alg ) != 0 )
2524 {
2525 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2526 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2527 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
2528 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2529 }
2530
2531 if( pk_alg != mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ) )
2532 {
2533 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2534 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2535 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
2536 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2537 }
2538 }
2539 else
2540 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
2541 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
2542 defined(MBEDTLS_SSL_PROTO_TLS1_1)
2543 if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 )
2544 {
2545 pk_alg = mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
2546
2547 /* Default hash for ECDSA is SHA-1 */
2548 if( pk_alg == MBEDTLS_PK_ECDSA && md_alg == MBEDTLS_MD_NONE )
2549 md_alg = MBEDTLS_MD_SHA1;
2550 }
2551 else
2552 #endif
2553 {
2554 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2555 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2556 }
2557
2558 /*
2559 * Read signature
2560 */
2561
2562 if( p > end - 2 )
2563 {
2564 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2565 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2566 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
2567 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2568 }
2569 sig_len = ( p[0] << 8 ) | p[1];
2570 p += 2;
2571
2572 if( p != end - sig_len )
2573 {
2574 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2575 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2576 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
2577 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
2578 }
2579
2580 MBEDTLS_SSL_DEBUG_BUF( 3, "signature", p, sig_len );
2581
2582 /*
2583 * Compute the hash that has been signed
2584 */
2585 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
2586 defined(MBEDTLS_SSL_PROTO_TLS1_1)
2587 if( md_alg == MBEDTLS_MD_NONE )
2588 {
2589 hashlen = 36;
2590 ret = mbedtls_ssl_get_key_exchange_md_ssl_tls( ssl, hash, params,
2591 params_len );
2592 if( ret != 0 )
2593 return( ret );
2594 }
2595 else
2596 #endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
2597 MBEDTLS_SSL_PROTO_TLS1_1 */
2598 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
2599 defined(MBEDTLS_SSL_PROTO_TLS1_2)
2600 if( md_alg != MBEDTLS_MD_NONE )
2601 {
2602 ret = mbedtls_ssl_get_key_exchange_md_tls1_2( ssl, hash, &hashlen,
2603 params, params_len,
2604 md_alg );
2605 if( ret != 0 )
2606 return( ret );
2607 }
2608 else
2609 #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
2610 MBEDTLS_SSL_PROTO_TLS1_2 */
2611 {
2612 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2613 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2614 }
2615
2616 MBEDTLS_SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen );
2617
2618 if( ssl->session_negotiate->peer_cert == NULL )
2619 {
2620 MBEDTLS_SSL_DEBUG_MSG( 2, ( "certificate required" ) );
2621 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2622 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
2623 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2624 }
2625
2626 /*
2627 * Verify signature
2628 */
2629 if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) )
2630 {
2631 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
2632 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2633 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
2634 return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
2635 }
2636
2637 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2638 if( ssl->handshake->ecrs_enabled )
2639 rs_ctx = &ssl->handshake->ecrs_ctx.pk;
2640 #endif
2641
2642 if( ( ret = mbedtls_pk_verify_restartable(
2643 &ssl->session_negotiate->peer_cert->pk,
2644 md_alg, hash, hashlen, p, sig_len, rs_ctx ) ) != 0 )
2645 {
2646 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2647 if( ret != MBEDTLS_ERR_ECP_IN_PROGRESS )
2648 #endif
2649 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2650 MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR );
2651 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_verify", ret );
2652 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2653 if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2654 ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
2655 #endif
2656 return( ret );
2657 }
2658 }
2659 #endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
2660
2661 exit:
2662 ssl->state++;
2663
2664 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server key exchange" ) );
2665
2666 return( 0 );
2667 }
2668
2669 #if ! defined(MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED)
ssl_parse_certificate_request(mbedtls_ssl_context * ssl)2670 static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
2671 {
2672 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
2673 ssl->transform_negotiate->ciphersuite_info;
2674
2675 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
2676
2677 if( ! mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
2678 {
2679 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
2680 ssl->state++;
2681 return( 0 );
2682 }
2683
2684 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2685 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2686 }
2687 #else /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
ssl_parse_certificate_request(mbedtls_ssl_context * ssl)2688 static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
2689 {
2690 int ret;
2691 unsigned char *buf;
2692 size_t n = 0;
2693 size_t cert_type_len = 0, dn_len = 0;
2694 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
2695 ssl->transform_negotiate->ciphersuite_info;
2696
2697 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
2698
2699 if( ! mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
2700 {
2701 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
2702 ssl->state++;
2703 return( 0 );
2704 }
2705
2706 if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
2707 {
2708 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
2709 return( ret );
2710 }
2711
2712 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
2713 {
2714 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
2715 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2716 MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
2717 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2718 }
2719
2720 ssl->state++;
2721 ssl->client_auth = ( ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST );
2722
2723 MBEDTLS_SSL_DEBUG_MSG( 3, ( "got %s certificate request",
2724 ssl->client_auth ? "a" : "no" ) );
2725
2726 if( ssl->client_auth == 0 )
2727 {
2728 /* Current message is probably the ServerHelloDone */
2729 ssl->keep_current_message = 1;
2730 goto exit;
2731 }
2732
2733 /*
2734 * struct {
2735 * ClientCertificateType certificate_types<1..2^8-1>;
2736 * SignatureAndHashAlgorithm
2737 * supported_signature_algorithms<2^16-1>; -- TLS 1.2 only
2738 * DistinguishedName certificate_authorities<0..2^16-1>;
2739 * } CertificateRequest;
2740 *
2741 * Since we only support a single certificate on clients, let's just
2742 * ignore all the information that's supposed to help us pick a
2743 * certificate.
2744 *
2745 * We could check that our certificate matches the request, and bail out
2746 * if it doesn't, but it's simpler to just send the certificate anyway,
2747 * and give the server the opportunity to decide if it should terminate
2748 * the connection when it doesn't like our certificate.
2749 *
2750 * Same goes for the hash in TLS 1.2's signature_algorithms: at this
2751 * point we only have one hash available (see comments in
2752 * write_certificate_verify), so let's just use what we have.
2753 *
2754 * However, we still minimally parse the message to check it is at least
2755 * superficially sane.
2756 */
2757 buf = ssl->in_msg;
2758
2759 /* certificate_types */
2760 if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) )
2761 {
2762 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
2763 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2764 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
2765 return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
2766 }
2767 cert_type_len = buf[mbedtls_ssl_hs_hdr_len( ssl )];
2768 n = cert_type_len;
2769
2770 /*
2771 * In the subsequent code there are two paths that read from buf:
2772 * * the length of the signature algorithms field (if minor version of
2773 * SSL is 3),
2774 * * distinguished name length otherwise.
2775 * Both reach at most the index:
2776 * ...hdr_len + 2 + n,
2777 * therefore the buffer length at this point must be greater than that
2778 * regardless of the actual code path.
2779 */
2780 if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
2781 {
2782 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
2783 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2784 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
2785 return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
2786 }
2787
2788 /* supported_signature_algorithms */
2789 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
2790 if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
2791 {
2792 size_t sig_alg_len = ( ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] << 8 )
2793 | ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n] ) );
2794 #if defined(MBEDTLS_DEBUG_C)
2795 unsigned char* sig_alg;
2796 size_t i;
2797 #endif
2798
2799 /*
2800 * The furthest access in buf is in the loop few lines below:
2801 * sig_alg[i + 1],
2802 * where:
2803 * sig_alg = buf + ...hdr_len + 3 + n,
2804 * max(i) = sig_alg_len - 1.
2805 * Therefore the furthest access is:
2806 * buf[...hdr_len + 3 + n + sig_alg_len - 1 + 1],
2807 * which reduces to:
2808 * buf[...hdr_len + 3 + n + sig_alg_len],
2809 * which is one less than we need the buf to be.
2810 */
2811 if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n + sig_alg_len )
2812 {
2813 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
2814 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2815 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
2816 return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
2817 }
2818
2819 #if defined(MBEDTLS_DEBUG_C)
2820 sig_alg = buf + mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n;
2821 for( i = 0; i < sig_alg_len; i += 2 )
2822 {
2823 MBEDTLS_SSL_DEBUG_MSG( 3, ( "Supported Signature Algorithm found: %d"
2824 ",%d", sig_alg[i], sig_alg[i + 1] ) );
2825 }
2826 #endif
2827
2828 n += 2 + sig_alg_len;
2829 }
2830 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
2831
2832 /* certificate_authorities */
2833 dn_len = ( ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] << 8 )
2834 | ( buf[mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n] ) );
2835
2836 n += dn_len;
2837 if( ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n )
2838 {
2839 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
2840 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2841 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
2842 return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
2843 }
2844
2845 exit:
2846 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
2847
2848 return( 0 );
2849 }
2850 #endif /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
2851
ssl_parse_server_hello_done(mbedtls_ssl_context * ssl)2852 static int ssl_parse_server_hello_done( mbedtls_ssl_context *ssl )
2853 {
2854 int ret;
2855
2856 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello done" ) );
2857
2858 if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
2859 {
2860 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
2861 return( ret );
2862 }
2863
2864 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
2865 {
2866 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
2867 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
2868 }
2869
2870 if( ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) ||
2871 ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_HELLO_DONE )
2872 {
2873 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
2874 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
2875 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
2876 return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO_DONE );
2877 }
2878
2879 ssl->state++;
2880
2881 #if defined(MBEDTLS_SSL_PROTO_DTLS)
2882 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
2883 mbedtls_ssl_recv_flight_completed( ssl );
2884 #endif
2885
2886 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello done" ) );
2887
2888 return( 0 );
2889 }
2890
ssl_write_client_key_exchange(mbedtls_ssl_context * ssl)2891 static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
2892 {
2893 int ret;
2894 size_t i, n;
2895 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
2896 ssl->transform_negotiate->ciphersuite_info;
2897
2898 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write client key exchange" ) );
2899
2900 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)
2901 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA )
2902 {
2903 /*
2904 * DHM key exchange -- send G^X mod P
2905 */
2906 n = ssl->handshake->dhm_ctx.len;
2907
2908 ssl->out_msg[4] = (unsigned char)( n >> 8 );
2909 ssl->out_msg[5] = (unsigned char)( n );
2910 i = 6;
2911
2912 ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
2913 (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
2914 &ssl->out_msg[i], n,
2915 ssl->conf->f_rng, ssl->conf->p_rng );
2916 if( ret != 0 )
2917 {
2918 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_public", ret );
2919 return( ret );
2920 }
2921
2922 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X );
2923 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX );
2924
2925 if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx,
2926 ssl->handshake->premaster,
2927 MBEDTLS_PREMASTER_SIZE,
2928 &ssl->handshake->pmslen,
2929 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
2930 {
2931 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret );
2932 return( ret );
2933 }
2934
2935 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
2936 }
2937 else
2938 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED */
2939 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
2940 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
2941 defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
2942 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
2943 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
2944 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA ||
2945 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
2946 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
2947 {
2948 /*
2949 * ECDH key exchange -- send client public value
2950 */
2951 i = 4;
2952
2953 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2954 if( ssl->handshake->ecrs_enabled )
2955 {
2956 if( ssl->handshake->ecrs_state == ssl_ecrs_cke_ecdh_calc_secret )
2957 goto ecdh_calc_secret;
2958
2959 mbedtls_ecdh_enable_restart( &ssl->handshake->ecdh_ctx );
2960 }
2961 #endif
2962
2963 ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx,
2964 &n,
2965 &ssl->out_msg[i], 1000,
2966 ssl->conf->f_rng, ssl->conf->p_rng );
2967 if( ret != 0 )
2968 {
2969 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_public", ret );
2970 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2971 if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
2972 ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
2973 #endif
2974 return( ret );
2975 }
2976
2977 MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
2978 MBEDTLS_DEBUG_ECDH_Q );
2979
2980 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2981 if( ssl->handshake->ecrs_enabled )
2982 {
2983 ssl->handshake->ecrs_n = n;
2984 ssl->handshake->ecrs_state = ssl_ecrs_cke_ecdh_calc_secret;
2985 }
2986
2987 ecdh_calc_secret:
2988 if( ssl->handshake->ecrs_enabled )
2989 n = ssl->handshake->ecrs_n;
2990 #endif
2991 if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
2992 &ssl->handshake->pmslen,
2993 ssl->handshake->premaster,
2994 MBEDTLS_MPI_MAX_SIZE,
2995 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
2996 {
2997 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_calc_secret", ret );
2998 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
2999 if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
3000 ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
3001 #endif
3002 return( ret );
3003 }
3004
3005 MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
3006 MBEDTLS_DEBUG_ECDH_Z );
3007 }
3008 else
3009 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
3010 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
3011 MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
3012 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
3013 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
3014 if( mbedtls_ssl_ciphersuite_uses_psk( ciphersuite_info ) )
3015 {
3016 /*
3017 * opaque psk_identity<0..2^16-1>;
3018 */
3019 if( ssl->conf->psk == NULL || ssl->conf->psk_identity == NULL )
3020 {
3021 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key for PSK" ) );
3022 return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
3023 }
3024
3025 i = 4;
3026 n = ssl->conf->psk_identity_len;
3027
3028 if( i + 2 + n > MBEDTLS_SSL_OUT_CONTENT_LEN )
3029 {
3030 MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity too long or "
3031 "SSL buffer too short" ) );
3032 return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
3033 }
3034
3035 ssl->out_msg[i++] = (unsigned char)( n >> 8 );
3036 ssl->out_msg[i++] = (unsigned char)( n );
3037
3038 memcpy( ssl->out_msg + i, ssl->conf->psk_identity, ssl->conf->psk_identity_len );
3039 i += ssl->conf->psk_identity_len;
3040
3041 #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
3042 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK )
3043 {
3044 n = 0;
3045 }
3046 else
3047 #endif
3048 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
3049 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
3050 {
3051 if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 2 ) ) != 0 )
3052 return( ret );
3053 }
3054 else
3055 #endif
3056 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
3057 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK )
3058 {
3059 /*
3060 * ClientDiffieHellmanPublic public (DHM send G^X mod P)
3061 */
3062 n = ssl->handshake->dhm_ctx.len;
3063
3064 if( i + 2 + n > MBEDTLS_SSL_OUT_CONTENT_LEN )
3065 {
3066 MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity or DHM size too long"
3067 " or SSL buffer too short" ) );
3068 return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
3069 }
3070
3071 ssl->out_msg[i++] = (unsigned char)( n >> 8 );
3072 ssl->out_msg[i++] = (unsigned char)( n );
3073
3074 ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
3075 (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
3076 &ssl->out_msg[i], n,
3077 ssl->conf->f_rng, ssl->conf->p_rng );
3078 if( ret != 0 )
3079 {
3080 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_public", ret );
3081 return( ret );
3082 }
3083 }
3084 else
3085 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
3086 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
3087 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
3088 {
3089 /*
3090 * ClientECDiffieHellmanPublic public;
3091 */
3092 ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx, &n,
3093 &ssl->out_msg[i], MBEDTLS_SSL_OUT_CONTENT_LEN - i,
3094 ssl->conf->f_rng, ssl->conf->p_rng );
3095 if( ret != 0 )
3096 {
3097 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_public", ret );
3098 return( ret );
3099 }
3100
3101 MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
3102 MBEDTLS_DEBUG_ECDH_Q );
3103 }
3104 else
3105 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
3106 {
3107 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3108 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3109 }
3110
3111 if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
3112 ciphersuite_info->key_exchange ) ) != 0 )
3113 {
3114 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
3115 return( ret );
3116 }
3117 }
3118 else
3119 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
3120 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
3121 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA )
3122 {
3123 i = 4;
3124 if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 0 ) ) != 0 )
3125 return( ret );
3126 }
3127 else
3128 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
3129 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
3130 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
3131 {
3132 i = 4;
3133
3134 ret = mbedtls_ecjpake_write_round_two( &ssl->handshake->ecjpake_ctx,
3135 ssl->out_msg + i, MBEDTLS_SSL_OUT_CONTENT_LEN - i, &n,
3136 ssl->conf->f_rng, ssl->conf->p_rng );
3137 if( ret != 0 )
3138 {
3139 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_write_round_two", ret );
3140 return( ret );
3141 }
3142
3143 ret = mbedtls_ecjpake_derive_secret( &ssl->handshake->ecjpake_ctx,
3144 ssl->handshake->premaster, 32, &ssl->handshake->pmslen,
3145 ssl->conf->f_rng, ssl->conf->p_rng );
3146 if( ret != 0 )
3147 {
3148 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_derive_secret", ret );
3149 return( ret );
3150 }
3151 }
3152 else
3153 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
3154 {
3155 ((void) ciphersuite_info);
3156 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3157 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3158 }
3159
3160 ssl->out_msglen = i + n;
3161 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
3162 ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE;
3163
3164 ssl->state++;
3165
3166 if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
3167 {
3168 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
3169 return( ret );
3170 }
3171
3172 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write client key exchange" ) );
3173
3174 return( 0 );
3175 }
3176
3177 #if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) && \
3178 !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) && \
3179 !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) && \
3180 !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
3181 !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \
3182 !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
ssl_write_certificate_verify(mbedtls_ssl_context * ssl)3183 static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
3184 {
3185 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
3186 ssl->transform_negotiate->ciphersuite_info;
3187 int ret;
3188
3189 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
3190
3191 if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
3192 {
3193 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
3194 return( ret );
3195 }
3196
3197 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
3198 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
3199 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
3200 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
3201 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
3202 {
3203 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
3204 ssl->state++;
3205 return( 0 );
3206 }
3207
3208 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3209 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3210 }
3211 #else
ssl_write_certificate_verify(mbedtls_ssl_context * ssl)3212 static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
3213 {
3214 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
3215 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
3216 ssl->transform_negotiate->ciphersuite_info;
3217 size_t n = 0, offset = 0;
3218 unsigned char hash[48];
3219 unsigned char *hash_start = hash;
3220 mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE;
3221 unsigned int hashlen;
3222 void *rs_ctx = NULL;
3223
3224 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
3225
3226 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
3227 if( ssl->handshake->ecrs_enabled &&
3228 ssl->handshake->ecrs_state == ssl_ecrs_crt_vrfy_sign )
3229 {
3230 goto sign;
3231 }
3232 #endif
3233
3234 if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
3235 {
3236 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
3237 return( ret );
3238 }
3239
3240 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
3241 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
3242 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
3243 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
3244 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
3245 {
3246 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
3247 ssl->state++;
3248 return( 0 );
3249 }
3250
3251 if( ssl->client_auth == 0 || mbedtls_ssl_own_cert( ssl ) == NULL )
3252 {
3253 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
3254 ssl->state++;
3255 return( 0 );
3256 }
3257
3258 if( mbedtls_ssl_own_key( ssl ) == NULL )
3259 {
3260 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key for certificate" ) );
3261 return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
3262 }
3263
3264 /*
3265 * Make a signature of the handshake digests
3266 */
3267 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
3268 if( ssl->handshake->ecrs_enabled )
3269 ssl->handshake->ecrs_state = ssl_ecrs_crt_vrfy_sign;
3270
3271 sign:
3272 #endif
3273
3274 ssl->handshake->calc_verify( ssl, hash );
3275
3276 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
3277 defined(MBEDTLS_SSL_PROTO_TLS1_1)
3278 if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
3279 {
3280 /*
3281 * digitally-signed struct {
3282 * opaque md5_hash[16];
3283 * opaque sha_hash[20];
3284 * };
3285 *
3286 * md5_hash
3287 * MD5(handshake_messages);
3288 *
3289 * sha_hash
3290 * SHA(handshake_messages);
3291 */
3292 hashlen = 36;
3293 md_alg = MBEDTLS_MD_NONE;
3294
3295 /*
3296 * For ECDSA, default hash is SHA-1 only
3297 */
3298 if( mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_ECDSA ) )
3299 {
3300 hash_start += 16;
3301 hashlen -= 16;
3302 md_alg = MBEDTLS_MD_SHA1;
3303 }
3304 }
3305 else
3306 #endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
3307 MBEDTLS_SSL_PROTO_TLS1_1 */
3308 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
3309 if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
3310 {
3311 /*
3312 * digitally-signed struct {
3313 * opaque handshake_messages[handshake_messages_length];
3314 * };
3315 *
3316 * Taking shortcut here. We assume that the server always allows the
3317 * PRF Hash function and has sent it in the allowed signature
3318 * algorithms list received in the Certificate Request message.
3319 *
3320 * Until we encounter a server that does not, we will take this
3321 * shortcut.
3322 *
3323 * Reason: Otherwise we should have running hashes for SHA512 and SHA224
3324 * in order to satisfy 'weird' needs from the server side.
3325 */
3326 if( ssl->transform_negotiate->ciphersuite_info->mac ==
3327 MBEDTLS_MD_SHA384 )
3328 {
3329 md_alg = MBEDTLS_MD_SHA384;
3330 ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA384;
3331 }
3332 else
3333 {
3334 md_alg = MBEDTLS_MD_SHA256;
3335 ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA256;
3336 }
3337 ssl->out_msg[5] = mbedtls_ssl_sig_from_pk( mbedtls_ssl_own_key( ssl ) );
3338
3339 /* Info from md_alg will be used instead */
3340 hashlen = 0;
3341 offset = 2;
3342 }
3343 else
3344 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
3345 {
3346 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3347 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3348 }
3349
3350 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
3351 if( ssl->handshake->ecrs_enabled )
3352 rs_ctx = &ssl->handshake->ecrs_ctx.pk;
3353 #endif
3354
3355 if( ( ret = mbedtls_pk_sign_restartable( mbedtls_ssl_own_key( ssl ),
3356 md_alg, hash_start, hashlen,
3357 ssl->out_msg + 6 + offset, &n,
3358 ssl->conf->f_rng, ssl->conf->p_rng, rs_ctx ) ) != 0 )
3359 {
3360 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_sign", ret );
3361 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
3362 if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
3363 ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
3364 #endif
3365 return( ret );
3366 }
3367
3368 ssl->out_msg[4 + offset] = (unsigned char)( n >> 8 );
3369 ssl->out_msg[5 + offset] = (unsigned char)( n );
3370
3371 ssl->out_msglen = 6 + n + offset;
3372 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
3373 ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE_VERIFY;
3374
3375 ssl->state++;
3376
3377 if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
3378 {
3379 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
3380 return( ret );
3381 }
3382
3383 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate verify" ) );
3384
3385 return( ret );
3386 }
3387 #endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED &&
3388 !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED &&
3389 !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED &&
3390 !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
3391 !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED &&
3392 !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
3393
3394 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
ssl_parse_new_session_ticket(mbedtls_ssl_context * ssl)3395 static int ssl_parse_new_session_ticket( mbedtls_ssl_context *ssl )
3396 {
3397 int ret;
3398 uint32_t lifetime;
3399 size_t ticket_len;
3400 unsigned char *ticket;
3401 const unsigned char *msg;
3402
3403 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse new session ticket" ) );
3404
3405 if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
3406 {
3407 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
3408 return( ret );
3409 }
3410
3411 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
3412 {
3413 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
3414 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
3415 MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
3416 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
3417 }
3418
3419 /*
3420 * struct {
3421 * uint32 ticket_lifetime_hint;
3422 * opaque ticket<0..2^16-1>;
3423 * } NewSessionTicket;
3424 *
3425 * 0 . 3 ticket_lifetime_hint
3426 * 4 . 5 ticket_len (n)
3427 * 6 . 5+n ticket content
3428 */
3429 if( ssl->in_msg[0] != MBEDTLS_SSL_HS_NEW_SESSION_TICKET ||
3430 ssl->in_hslen < 6 + mbedtls_ssl_hs_hdr_len( ssl ) )
3431 {
3432 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
3433 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
3434 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
3435 return( MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
3436 }
3437
3438 msg = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
3439
3440 lifetime = ( ((uint32_t) msg[0]) << 24 ) | ( msg[1] << 16 ) |
3441 ( msg[2] << 8 ) | ( msg[3] );
3442
3443 ticket_len = ( msg[4] << 8 ) | ( msg[5] );
3444
3445 if( ticket_len + 6 + mbedtls_ssl_hs_hdr_len( ssl ) != ssl->in_hslen )
3446 {
3447 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
3448 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
3449 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
3450 return( MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
3451 }
3452
3453 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket length: %d", ticket_len ) );
3454
3455 /* We're not waiting for a NewSessionTicket message any more */
3456 ssl->handshake->new_session_ticket = 0;
3457 ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
3458
3459 /*
3460 * Zero-length ticket means the server changed his mind and doesn't want
3461 * to send a ticket after all, so just forget it
3462 */
3463 if( ticket_len == 0 )
3464 return( 0 );
3465
3466 mbedtls_platform_zeroize( ssl->session_negotiate->ticket,
3467 ssl->session_negotiate->ticket_len );
3468 mbedtls_free( ssl->session_negotiate->ticket );
3469 ssl->session_negotiate->ticket = NULL;
3470 ssl->session_negotiate->ticket_len = 0;
3471
3472 if( ( ticket = mbedtls_calloc( 1, ticket_len ) ) == NULL )
3473 {
3474 MBEDTLS_SSL_DEBUG_MSG( 1, ( "ticket alloc failed" ) );
3475 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
3476 MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
3477 return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
3478 }
3479
3480 memcpy( ticket, msg + 6, ticket_len );
3481
3482 ssl->session_negotiate->ticket = ticket;
3483 ssl->session_negotiate->ticket_len = ticket_len;
3484 ssl->session_negotiate->ticket_lifetime = lifetime;
3485
3486 /*
3487 * RFC 5077 section 3.4:
3488 * "If the client receives a session ticket from the server, then it
3489 * discards any Session ID that was sent in the ServerHello."
3490 */
3491 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket in use, discarding session id" ) );
3492 ssl->session_negotiate->id_len = 0;
3493
3494 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse new session ticket" ) );
3495
3496 return( 0 );
3497 }
3498 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
3499
3500 /*
3501 * SSL handshake -- client side -- single step
3502 */
mbedtls_ssl_handshake_client_step(mbedtls_ssl_context * ssl)3503 int mbedtls_ssl_handshake_client_step( mbedtls_ssl_context *ssl )
3504 {
3505 int ret = 0;
3506
3507 if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->handshake == NULL )
3508 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
3509
3510 MBEDTLS_SSL_DEBUG_MSG( 2, ( "client state: %d", ssl->state ) );
3511
3512 if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
3513 return( ret );
3514
3515 #if defined(MBEDTLS_SSL_PROTO_DTLS)
3516 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
3517 ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
3518 {
3519 if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
3520 return( ret );
3521 }
3522 #endif /* MBEDTLS_SSL_PROTO_DTLS */
3523
3524 /* Change state now, so that it is right in mbedtls_ssl_read_record(), used
3525 * by DTLS for dropping out-of-sequence ChangeCipherSpec records */
3526 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
3527 if( ssl->state == MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC &&
3528 ssl->handshake->new_session_ticket != 0 )
3529 {
3530 ssl->state = MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET;
3531 }
3532 #endif
3533
3534 switch( ssl->state )
3535 {
3536 case MBEDTLS_SSL_HELLO_REQUEST:
3537 ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
3538 break;
3539
3540 /*
3541 * ==> ClientHello
3542 */
3543 case MBEDTLS_SSL_CLIENT_HELLO:
3544 ret = ssl_write_client_hello( ssl );
3545 break;
3546
3547 /*
3548 * <== ServerHello
3549 * Certificate
3550 * ( ServerKeyExchange )
3551 * ( CertificateRequest )
3552 * ServerHelloDone
3553 */
3554 case MBEDTLS_SSL_SERVER_HELLO:
3555 ret = ssl_parse_server_hello( ssl );
3556 break;
3557
3558 case MBEDTLS_SSL_SERVER_CERTIFICATE:
3559 ret = mbedtls_ssl_parse_certificate( ssl );
3560 break;
3561
3562 case MBEDTLS_SSL_SERVER_KEY_EXCHANGE:
3563 ret = ssl_parse_server_key_exchange( ssl );
3564 break;
3565
3566 case MBEDTLS_SSL_CERTIFICATE_REQUEST:
3567 ret = ssl_parse_certificate_request( ssl );
3568 break;
3569
3570 case MBEDTLS_SSL_SERVER_HELLO_DONE:
3571 ret = ssl_parse_server_hello_done( ssl );
3572 break;
3573
3574 /*
3575 * ==> ( Certificate/Alert )
3576 * ClientKeyExchange
3577 * ( CertificateVerify )
3578 * ChangeCipherSpec
3579 * Finished
3580 */
3581 case MBEDTLS_SSL_CLIENT_CERTIFICATE:
3582 ret = mbedtls_ssl_write_certificate( ssl );
3583 break;
3584
3585 case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE:
3586 ret = ssl_write_client_key_exchange( ssl );
3587 break;
3588
3589 case MBEDTLS_SSL_CERTIFICATE_VERIFY:
3590 ret = ssl_write_certificate_verify( ssl );
3591 break;
3592
3593 case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC:
3594 ret = mbedtls_ssl_write_change_cipher_spec( ssl );
3595 break;
3596
3597 case MBEDTLS_SSL_CLIENT_FINISHED:
3598 ret = mbedtls_ssl_write_finished( ssl );
3599 break;
3600
3601 /*
3602 * <== ( NewSessionTicket )
3603 * ChangeCipherSpec
3604 * Finished
3605 */
3606 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
3607 case MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET:
3608 ret = ssl_parse_new_session_ticket( ssl );
3609 break;
3610 #endif
3611
3612 case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC:
3613 ret = mbedtls_ssl_parse_change_cipher_spec( ssl );
3614 break;
3615
3616 case MBEDTLS_SSL_SERVER_FINISHED:
3617 ret = mbedtls_ssl_parse_finished( ssl );
3618 break;
3619
3620 case MBEDTLS_SSL_FLUSH_BUFFERS:
3621 MBEDTLS_SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
3622 ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP;
3623 break;
3624
3625 case MBEDTLS_SSL_HANDSHAKE_WRAPUP:
3626 mbedtls_ssl_handshake_wrapup( ssl );
3627 break;
3628
3629 default:
3630 MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
3631 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
3632 }
3633
3634 return( ret );
3635 }
3636 #endif /* MBEDTLS_SSL_CLI_C */
3637