1 /*
2 * TLS server-side functions
3 *
4 * Copyright The Mbed TLS Contributors
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
20 #include "common.h"
21
22 #if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_PROTO_TLS1_2)
23
24 #include "mbedtls/platform.h"
25
26 #include "mbedtls/ssl.h"
27 #include "ssl_misc.h"
28 #include "mbedtls/debug.h"
29 #include "mbedtls/error.h"
30 #include "mbedtls/platform_util.h"
31 #include "constant_time_internal.h"
32 #include "mbedtls/constant_time.h"
33 #include "hash_info.h"
34
35 #include <string.h>
36
37 #if defined(MBEDTLS_ECP_C)
38 #include "mbedtls/ecp.h"
39 #endif
40
41 #if defined(MBEDTLS_HAVE_TIME)
42 #include "mbedtls/platform_time.h"
43 #endif
44
45 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
mbedtls_ssl_set_client_transport_id(mbedtls_ssl_context * ssl,const unsigned char * info,size_t ilen)46 int mbedtls_ssl_set_client_transport_id( mbedtls_ssl_context *ssl,
47 const unsigned char *info,
48 size_t ilen )
49 {
50 if( ssl->conf->endpoint != MBEDTLS_SSL_IS_SERVER )
51 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
52
53 mbedtls_free( ssl->cli_id );
54
55 if( ( ssl->cli_id = mbedtls_calloc( 1, ilen ) ) == NULL )
56 return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
57
58 memcpy( ssl->cli_id, info, ilen );
59 ssl->cli_id_len = ilen;
60
61 return( 0 );
62 }
63
mbedtls_ssl_conf_dtls_cookies(mbedtls_ssl_config * conf,mbedtls_ssl_cookie_write_t * f_cookie_write,mbedtls_ssl_cookie_check_t * f_cookie_check,void * p_cookie)64 void mbedtls_ssl_conf_dtls_cookies( mbedtls_ssl_config *conf,
65 mbedtls_ssl_cookie_write_t *f_cookie_write,
66 mbedtls_ssl_cookie_check_t *f_cookie_check,
67 void *p_cookie )
68 {
69 conf->f_cookie_write = f_cookie_write;
70 conf->f_cookie_check = f_cookie_check;
71 conf->p_cookie = p_cookie;
72 }
73 #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
74
75 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
76 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_conf_has_psk_or_cb(mbedtls_ssl_config const * conf)77 static int ssl_conf_has_psk_or_cb( mbedtls_ssl_config const *conf )
78 {
79 if( conf->f_psk != NULL )
80 return( 1 );
81
82 if( conf->psk_identity_len == 0 || conf->psk_identity == NULL )
83 return( 0 );
84
85
86 #if defined(MBEDTLS_USE_PSA_CRYPTO)
87 if( ! mbedtls_svc_key_id_is_null( conf->psk_opaque ) )
88 return( 1 );
89 #endif /* MBEDTLS_USE_PSA_CRYPTO */
90
91 if( conf->psk != NULL && conf->psk_len != 0 )
92 return( 1 );
93
94 return( 0 );
95 }
96 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
97
98 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_renegotiation_info(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)99 static int ssl_parse_renegotiation_info( mbedtls_ssl_context *ssl,
100 const unsigned char *buf,
101 size_t len )
102 {
103 #if defined(MBEDTLS_SSL_RENEGOTIATION)
104 if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
105 {
106 /* Check verify-data in constant-time. The length OTOH is no secret */
107 if( len != 1 + ssl->verify_data_len ||
108 buf[0] != ssl->verify_data_len ||
109 mbedtls_ct_memcmp( buf + 1, ssl->peer_verify_data,
110 ssl->verify_data_len ) != 0 )
111 {
112 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
113 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
114 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
115 return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
116 }
117 }
118 else
119 #endif /* MBEDTLS_SSL_RENEGOTIATION */
120 {
121 if( len != 1 || buf[0] != 0x0 )
122 {
123 MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
124 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
125 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
126 return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
127 }
128
129 ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
130 }
131
132 return( 0 );
133 }
134
135 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
136 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
137 /*
138 * Function for parsing a supported groups (TLS 1.3) or supported elliptic
139 * curves (TLS 1.2) extension.
140 *
141 * The "extension_data" field of a supported groups extension contains a
142 * "NamedGroupList" value (TLS 1.3 RFC8446):
143 * enum {
144 * secp256r1(0x0017), secp384r1(0x0018), secp521r1(0x0019),
145 * x25519(0x001D), x448(0x001E),
146 * ffdhe2048(0x0100), ffdhe3072(0x0101), ffdhe4096(0x0102),
147 * ffdhe6144(0x0103), ffdhe8192(0x0104),
148 * ffdhe_private_use(0x01FC..0x01FF),
149 * ecdhe_private_use(0xFE00..0xFEFF),
150 * (0xFFFF)
151 * } NamedGroup;
152 * struct {
153 * NamedGroup named_group_list<2..2^16-1>;
154 * } NamedGroupList;
155 *
156 * The "extension_data" field of a supported elliptic curves extension contains
157 * a "NamedCurveList" value (TLS 1.2 RFC 8422):
158 * enum {
159 * deprecated(1..22),
160 * secp256r1 (23), secp384r1 (24), secp521r1 (25),
161 * x25519(29), x448(30),
162 * reserved (0xFE00..0xFEFF),
163 * deprecated(0xFF01..0xFF02),
164 * (0xFFFF)
165 * } NamedCurve;
166 * struct {
167 * NamedCurve named_curve_list<2..2^16-1>
168 * } NamedCurveList;
169 *
170 * The TLS 1.3 supported groups extension was defined to be a compatible
171 * generalization of the TLS 1.2 supported elliptic curves extension. They both
172 * share the same extension identifier.
173 *
174 * DHE groups are not supported yet.
175 */
176 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_supported_groups_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)177 static int ssl_parse_supported_groups_ext( mbedtls_ssl_context *ssl,
178 const unsigned char *buf,
179 size_t len )
180 {
181 size_t list_size, our_size;
182 const unsigned char *p;
183 const mbedtls_ecp_curve_info *curve_info, **curves;
184
185 if ( len < 2 ) {
186 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
187 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
188 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
189 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
190 }
191 list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
192 if( list_size + 2 != len ||
193 list_size % 2 != 0 )
194 {
195 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
196 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
197 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
198 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
199 }
200
201 /* Should never happen unless client duplicates the extension */
202 if( ssl->handshake->curves != NULL )
203 {
204 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
205 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
206 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
207 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
208 }
209
210 /* Don't allow our peer to make us allocate too much memory,
211 * and leave room for a final 0 */
212 our_size = list_size / 2 + 1;
213 if( our_size > MBEDTLS_ECP_DP_MAX )
214 our_size = MBEDTLS_ECP_DP_MAX;
215
216 if( ( curves = mbedtls_calloc( our_size, sizeof( *curves ) ) ) == NULL )
217 {
218 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
219 MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
220 return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
221 }
222
223 ssl->handshake->curves = curves;
224
225 p = buf + 2;
226 while( list_size > 0 && our_size > 1 )
227 {
228 curve_info = mbedtls_ecp_curve_info_from_tls_id( ( p[0] << 8 ) | p[1] );
229
230 if( curve_info != NULL )
231 {
232 *curves++ = curve_info;
233 our_size--;
234 }
235
236 list_size -= 2;
237 p += 2;
238 }
239
240 return( 0 );
241 }
242
243 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_supported_point_formats(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)244 static int ssl_parse_supported_point_formats( mbedtls_ssl_context *ssl,
245 const unsigned char *buf,
246 size_t len )
247 {
248 size_t list_size;
249 const unsigned char *p;
250
251 if( len == 0 || (size_t)( buf[0] + 1 ) != len )
252 {
253 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
254 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
255 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
256 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
257 }
258 list_size = buf[0];
259
260 p = buf + 1;
261 while( list_size > 0 )
262 {
263 if( p[0] == MBEDTLS_ECP_PF_UNCOMPRESSED ||
264 p[0] == MBEDTLS_ECP_PF_COMPRESSED )
265 {
266 #if !defined(MBEDTLS_USE_PSA_CRYPTO) && \
267 ( defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) )
268 ssl->handshake->ecdh_ctx.point_format = p[0];
269 #endif /* !MBEDTLS_USE_PSA_CRYPTO &&
270 ( MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ) */
271 #if !defined(MBEDTLS_USE_PSA_CRYPTO) && \
272 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
273 mbedtls_ecjpake_set_point_format( &ssl->handshake->ecjpake_ctx,
274 p[0] );
275 #endif /* !MBEDTLS_USE_PSA_CRYPTO && MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
276 MBEDTLS_SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) );
277 return( 0 );
278 }
279
280 list_size--;
281 p++;
282 }
283
284 return( 0 );
285 }
286 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
287 MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
288
289 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
290 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_ecjpake_kkpp(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)291 static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl,
292 const unsigned char *buf,
293 size_t len)
294 {
295 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
296
297 #if defined(MBEDTLS_USE_PSA_CRYPTO)
298 if( ssl->handshake->psa_pake_ctx_is_ok != 1 )
299 #else
300 if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
301 #endif /* MBEDTLS_USE_PSA_CRYPTO */
302 {
303 MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip ecjpake kkpp extension" ) );
304 return( 0 );
305 }
306
307 #if defined(MBEDTLS_USE_PSA_CRYPTO)
308 if( ( ret = mbedtls_psa_ecjpake_read_round(
309 &ssl->handshake->psa_pake_ctx, buf, len,
310 MBEDTLS_ECJPAKE_ROUND_ONE ) ) != 0 )
311 {
312 psa_destroy_key( ssl->handshake->psa_pake_password );
313 psa_pake_abort( &ssl->handshake->psa_pake_ctx );
314
315 MBEDTLS_SSL_DEBUG_RET( 1, "psa_pake_input round one", ret );
316 mbedtls_ssl_send_alert_message(
317 ssl,
318 MBEDTLS_SSL_ALERT_LEVEL_FATAL,
319 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
320
321 return( ret );
322 }
323 #else
324 if( ( ret = mbedtls_ecjpake_read_round_one( &ssl->handshake->ecjpake_ctx,
325 buf, len ) ) != 0 )
326 {
327 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_one", ret );
328 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
329 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
330 return( ret );
331 }
332 #endif /* MBEDTLS_USE_PSA_CRYPTO */
333
334 /* Only mark the extension as OK when we're sure it is */
335 ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK;
336
337 return( 0 );
338 }
339 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
340
341 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
342 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_max_fragment_length_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)343 static int ssl_parse_max_fragment_length_ext( mbedtls_ssl_context *ssl,
344 const unsigned char *buf,
345 size_t len )
346 {
347 if( len != 1 || buf[0] >= MBEDTLS_SSL_MAX_FRAG_LEN_INVALID )
348 {
349 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
350 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
351 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
352 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
353 }
354
355 ssl->session_negotiate->mfl_code = buf[0];
356
357 return( 0 );
358 }
359 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
360
361 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
362 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_cid_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)363 static int ssl_parse_cid_ext( mbedtls_ssl_context *ssl,
364 const unsigned char *buf,
365 size_t len )
366 {
367 size_t peer_cid_len;
368
369 /* CID extension only makes sense in DTLS */
370 if( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM )
371 {
372 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
373 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
374 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
375 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
376 }
377
378 /*
379 * struct {
380 * opaque cid<0..2^8-1>;
381 * } ConnectionId;
382 */
383
384 if( len < 1 )
385 {
386 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
387 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
388 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
389 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
390 }
391
392 peer_cid_len = *buf++;
393 len--;
394
395 if( len != peer_cid_len )
396 {
397 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
398 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
399 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
400 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
401 }
402
403 /* Ignore CID if the user has disabled its use. */
404 if( ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED )
405 {
406 /* Leave ssl->handshake->cid_in_use in its default
407 * value of MBEDTLS_SSL_CID_DISABLED. */
408 MBEDTLS_SSL_DEBUG_MSG( 3, ( "Client sent CID extension, but CID disabled" ) );
409 return( 0 );
410 }
411
412 if( peer_cid_len > MBEDTLS_SSL_CID_OUT_LEN_MAX )
413 {
414 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
415 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
416 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
417 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
418 }
419
420 ssl->handshake->cid_in_use = MBEDTLS_SSL_CID_ENABLED;
421 ssl->handshake->peer_cid_len = (uint8_t) peer_cid_len;
422 memcpy( ssl->handshake->peer_cid, buf, peer_cid_len );
423
424 MBEDTLS_SSL_DEBUG_MSG( 3, ( "Use of CID extension negotiated" ) );
425 MBEDTLS_SSL_DEBUG_BUF( 3, "Client CID", buf, peer_cid_len );
426
427 return( 0 );
428 }
429 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
430
431 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
432 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_encrypt_then_mac_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)433 static int ssl_parse_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
434 const unsigned char *buf,
435 size_t len )
436 {
437 if( len != 0 )
438 {
439 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
440 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
441 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
442 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
443 }
444
445 ((void) buf);
446
447 if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED )
448 {
449 ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED;
450 }
451
452 return( 0 );
453 }
454 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
455
456 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
457 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_extended_ms_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)458 static int ssl_parse_extended_ms_ext( mbedtls_ssl_context *ssl,
459 const unsigned char *buf,
460 size_t len )
461 {
462 if( len != 0 )
463 {
464 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
465 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
466 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
467 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
468 }
469
470 ((void) buf);
471
472 if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED )
473 {
474 ssl->handshake->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED;
475 }
476
477 return( 0 );
478 }
479 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
480
481 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
482 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_session_ticket_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t len)483 static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
484 unsigned char *buf,
485 size_t len )
486 {
487 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
488 mbedtls_ssl_session session;
489
490 mbedtls_ssl_session_init( &session );
491
492 if( ssl->conf->f_ticket_parse == NULL ||
493 ssl->conf->f_ticket_write == NULL )
494 {
495 return( 0 );
496 }
497
498 /* Remember the client asked us to send a new ticket */
499 ssl->handshake->new_session_ticket = 1;
500
501 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket length: %" MBEDTLS_PRINTF_SIZET, len ) );
502
503 if( len == 0 )
504 return( 0 );
505
506 #if defined(MBEDTLS_SSL_RENEGOTIATION)
507 if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
508 {
509 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket rejected: renegotiating" ) );
510 return( 0 );
511 }
512 #endif /* MBEDTLS_SSL_RENEGOTIATION */
513
514 /*
515 * Failures are ok: just ignore the ticket and proceed.
516 */
517 if( ( ret = ssl->conf->f_ticket_parse( ssl->conf->p_ticket, &session,
518 buf, len ) ) != 0 )
519 {
520 mbedtls_ssl_session_free( &session );
521
522 if( ret == MBEDTLS_ERR_SSL_INVALID_MAC )
523 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket is not authentic" ) );
524 else if( ret == MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED )
525 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket is expired" ) );
526 else
527 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_parse", ret );
528
529 return( 0 );
530 }
531
532 /*
533 * Keep the session ID sent by the client, since we MUST send it back to
534 * inform them we're accepting the ticket (RFC 5077 section 3.4)
535 */
536 session.id_len = ssl->session_negotiate->id_len;
537 memcpy( &session.id, ssl->session_negotiate->id, session.id_len );
538
539 mbedtls_ssl_session_free( ssl->session_negotiate );
540 memcpy( ssl->session_negotiate, &session, sizeof( mbedtls_ssl_session ) );
541
542 /* Zeroize instead of free as we copied the content */
543 mbedtls_platform_zeroize( &session, sizeof( mbedtls_ssl_session ) );
544
545 MBEDTLS_SSL_DEBUG_MSG( 3, ( "session successfully restored from ticket" ) );
546
547 ssl->handshake->resume = 1;
548
549 /* Don't send a new ticket after all, this one is OK */
550 ssl->handshake->new_session_ticket = 0;
551
552 return( 0 );
553 }
554 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
555
556 #if defined(MBEDTLS_SSL_DTLS_SRTP)
557 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_use_srtp_ext(mbedtls_ssl_context * ssl,const unsigned char * buf,size_t len)558 static int ssl_parse_use_srtp_ext( mbedtls_ssl_context *ssl,
559 const unsigned char *buf,
560 size_t len )
561 {
562 mbedtls_ssl_srtp_profile client_protection = MBEDTLS_TLS_SRTP_UNSET;
563 size_t i,j;
564 size_t profile_length;
565 uint16_t mki_length;
566 /*! 2 bytes for profile length and 1 byte for mki len */
567 const size_t size_of_lengths = 3;
568
569 /* If use_srtp is not configured, just ignore the extension */
570 if( ( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) ||
571 ( ssl->conf->dtls_srtp_profile_list == NULL ) ||
572 ( ssl->conf->dtls_srtp_profile_list_len == 0 ) )
573 {
574 return( 0 );
575 }
576
577 /* RFC5764 section 4.1.1
578 * uint8 SRTPProtectionProfile[2];
579 *
580 * struct {
581 * SRTPProtectionProfiles SRTPProtectionProfiles;
582 * opaque srtp_mki<0..255>;
583 * } UseSRTPData;
584
585 * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>;
586 */
587
588 /*
589 * Min length is 5: at least one protection profile(2 bytes)
590 * and length(2 bytes) + srtp_mki length(1 byte)
591 * Check here that we have at least 2 bytes of protection profiles length
592 * and one of srtp_mki length
593 */
594 if( len < size_of_lengths )
595 {
596 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
597 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
598 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
599 }
600
601 ssl->dtls_srtp_info.chosen_dtls_srtp_profile = MBEDTLS_TLS_SRTP_UNSET;
602
603 /* first 2 bytes are protection profile length(in bytes) */
604 profile_length = ( buf[0] << 8 ) | buf[1];
605 buf += 2;
606
607 /* The profile length cannot be bigger than input buffer size - lengths fields */
608 if( profile_length > len - size_of_lengths ||
609 profile_length % 2 != 0 ) /* profiles are 2 bytes long, so the length must be even */
610 {
611 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
612 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
613 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
614 }
615 /*
616 * parse the extension list values are defined in
617 * http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml
618 */
619 for( j = 0; j < profile_length; j += 2 )
620 {
621 uint16_t protection_profile_value = buf[j] << 8 | buf[j + 1];
622 client_protection = mbedtls_ssl_check_srtp_profile_value( protection_profile_value );
623
624 if( client_protection != MBEDTLS_TLS_SRTP_UNSET )
625 {
626 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found srtp profile: %s",
627 mbedtls_ssl_get_srtp_profile_as_string(
628 client_protection ) ) );
629 }
630 else
631 {
632 continue;
633 }
634 /* check if suggested profile is in our list */
635 for( i = 0; i < ssl->conf->dtls_srtp_profile_list_len; i++)
636 {
637 if( client_protection == ssl->conf->dtls_srtp_profile_list[i] )
638 {
639 ssl->dtls_srtp_info.chosen_dtls_srtp_profile = ssl->conf->dtls_srtp_profile_list[i];
640 MBEDTLS_SSL_DEBUG_MSG( 3, ( "selected srtp profile: %s",
641 mbedtls_ssl_get_srtp_profile_as_string(
642 client_protection ) ) );
643 break;
644 }
645 }
646 if( ssl->dtls_srtp_info.chosen_dtls_srtp_profile != MBEDTLS_TLS_SRTP_UNSET )
647 break;
648 }
649 buf += profile_length; /* buf points to the mki length */
650 mki_length = *buf;
651 buf++;
652
653 if( mki_length > MBEDTLS_TLS_SRTP_MAX_MKI_LENGTH ||
654 mki_length + profile_length + size_of_lengths != len )
655 {
656 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
657 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
658 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
659 }
660
661 /* Parse the mki only if present and mki is supported locally */
662 if( ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED &&
663 mki_length > 0 )
664 {
665 ssl->dtls_srtp_info.mki_len = mki_length;
666
667 memcpy( ssl->dtls_srtp_info.mki_value, buf, mki_length );
668
669 MBEDTLS_SSL_DEBUG_BUF( 3, "using mki", ssl->dtls_srtp_info.mki_value,
670 ssl->dtls_srtp_info.mki_len );
671 }
672
673 return( 0 );
674 }
675 #endif /* MBEDTLS_SSL_DTLS_SRTP */
676
677 /*
678 * Auxiliary functions for ServerHello parsing and related actions
679 */
680
681 #if defined(MBEDTLS_X509_CRT_PARSE_C)
682 /*
683 * Return 0 if the given key uses one of the acceptable curves, -1 otherwise
684 */
685 #if defined(MBEDTLS_ECDSA_C)
686 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_check_key_curve(mbedtls_pk_context * pk,const mbedtls_ecp_curve_info ** curves)687 static int ssl_check_key_curve( mbedtls_pk_context *pk,
688 const mbedtls_ecp_curve_info **curves )
689 {
690 const mbedtls_ecp_curve_info **crv = curves;
691 mbedtls_ecp_group_id grp_id = mbedtls_pk_ec( *pk )->grp.id;
692
693 while( *crv != NULL )
694 {
695 if( (*crv)->grp_id == grp_id )
696 return( 0 );
697 crv++;
698 }
699
700 return( -1 );
701 }
702 #endif /* MBEDTLS_ECDSA_C */
703
704 /*
705 * Try picking a certificate for this ciphersuite,
706 * return 0 on success and -1 on failure.
707 */
708 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_pick_cert(mbedtls_ssl_context * ssl,const mbedtls_ssl_ciphersuite_t * ciphersuite_info)709 static int ssl_pick_cert( mbedtls_ssl_context *ssl,
710 const mbedtls_ssl_ciphersuite_t * ciphersuite_info )
711 {
712 mbedtls_ssl_key_cert *cur, *list;
713 #if defined(MBEDTLS_USE_PSA_CRYPTO)
714 psa_algorithm_t pk_alg =
715 mbedtls_ssl_get_ciphersuite_sig_pk_psa_alg( ciphersuite_info );
716 psa_key_usage_t pk_usage =
717 mbedtls_ssl_get_ciphersuite_sig_pk_psa_usage( ciphersuite_info );
718 #else
719 mbedtls_pk_type_t pk_alg =
720 mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
721 #endif /* MBEDTLS_USE_PSA_CRYPTO */
722 uint32_t flags;
723
724 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
725 if( ssl->handshake->sni_key_cert != NULL )
726 list = ssl->handshake->sni_key_cert;
727 else
728 #endif
729 list = ssl->conf->key_cert;
730
731 int pk_alg_is_none = 0;
732 #if defined(MBEDTLS_USE_PSA_CRYPTO)
733 pk_alg_is_none = ( pk_alg == PSA_ALG_NONE );
734 #else
735 pk_alg_is_none = ( pk_alg == MBEDTLS_PK_NONE );
736 #endif /* MBEDTLS_USE_PSA_CRYPTO */
737 if( pk_alg_is_none )
738 return( 0 );
739
740 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite requires certificate" ) );
741
742 if( list == NULL )
743 {
744 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server has no certificate" ) );
745 return( -1 );
746 }
747
748 for( cur = list; cur != NULL; cur = cur->next )
749 {
750 flags = 0;
751 MBEDTLS_SSL_DEBUG_CRT( 3, "candidate certificate chain, certificate",
752 cur->cert );
753
754 int key_type_matches = 0;
755 #if defined(MBEDTLS_USE_PSA_CRYPTO)
756 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
757 key_type_matches = ( ( ssl->conf->f_async_sign_start != NULL ||
758 ssl->conf->f_async_decrypt_start != NULL ||
759 mbedtls_pk_can_do_ext( cur->key, pk_alg, pk_usage ) ) &&
760 mbedtls_pk_can_do_ext( &cur->cert->pk, pk_alg, pk_usage ) );
761 #else
762 key_type_matches = (
763 mbedtls_pk_can_do_ext( cur->key, pk_alg, pk_usage ) );
764 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
765 #else
766 key_type_matches = mbedtls_pk_can_do( &cur->cert->pk, pk_alg );
767 #endif /* MBEDTLS_USE_PSA_CRYPTO */
768 if( !key_type_matches )
769 {
770 MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: key type" ) );
771 continue;
772 }
773
774 /*
775 * This avoids sending the client a cert it'll reject based on
776 * keyUsage or other extensions.
777 *
778 * It also allows the user to provision different certificates for
779 * different uses based on keyUsage, eg if they want to avoid signing
780 * and decrypting with the same RSA key.
781 */
782 if( mbedtls_ssl_check_cert_usage( cur->cert, ciphersuite_info,
783 MBEDTLS_SSL_IS_SERVER, &flags ) != 0 )
784 {
785 MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: "
786 "(extended) key usage extension" ) );
787 continue;
788 }
789
790 #if defined(MBEDTLS_ECDSA_C)
791 if( pk_alg == MBEDTLS_PK_ECDSA &&
792 ssl_check_key_curve( &cur->cert->pk, ssl->handshake->curves ) != 0 )
793 {
794 MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: elliptic curve" ) );
795 continue;
796 }
797 #endif
798
799 /* If we get there, we got a winner */
800 break;
801 }
802
803 /* Do not update ssl->handshake->key_cert unless there is a match */
804 if( cur != NULL )
805 {
806 ssl->handshake->key_cert = cur;
807 MBEDTLS_SSL_DEBUG_CRT( 3, "selected certificate chain, certificate",
808 ssl->handshake->key_cert->cert );
809 return( 0 );
810 }
811
812 return( -1 );
813 }
814 #endif /* MBEDTLS_X509_CRT_PARSE_C */
815
816 /*
817 * Check if a given ciphersuite is suitable for use with our config/keys/etc
818 * Sets ciphersuite_info only if the suite matches.
819 */
820 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_ciphersuite_match(mbedtls_ssl_context * ssl,int suite_id,const mbedtls_ssl_ciphersuite_t ** ciphersuite_info)821 static int ssl_ciphersuite_match( mbedtls_ssl_context *ssl, int suite_id,
822 const mbedtls_ssl_ciphersuite_t **ciphersuite_info )
823 {
824 const mbedtls_ssl_ciphersuite_t *suite_info;
825
826 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
827 mbedtls_pk_type_t sig_type;
828 #endif
829
830 suite_info = mbedtls_ssl_ciphersuite_from_id( suite_id );
831 if( suite_info == NULL )
832 {
833 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
834 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
835 }
836
837 MBEDTLS_SSL_DEBUG_MSG( 3, ( "trying ciphersuite: %#04x (%s)",
838 (unsigned int) suite_id, suite_info->name ) );
839
840 if( suite_info->min_tls_version > ssl->tls_version ||
841 suite_info->max_tls_version < ssl->tls_version )
842 {
843 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: version" ) );
844 return( 0 );
845 }
846
847 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
848 if( suite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE &&
849 ( ssl->handshake->cli_exts & MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK ) == 0 )
850 {
851 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: ecjpake "
852 "not configured or ext missing" ) );
853 return( 0 );
854 }
855 #endif
856
857
858 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
859 if( mbedtls_ssl_ciphersuite_uses_ec( suite_info ) &&
860 ( ssl->handshake->curves == NULL ||
861 ssl->handshake->curves[0] == NULL ) )
862 {
863 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: "
864 "no common elliptic curve" ) );
865 return( 0 );
866 }
867 #endif
868
869 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
870 /* If the ciphersuite requires a pre-shared key and we don't
871 * have one, skip it now rather than failing later */
872 if( mbedtls_ssl_ciphersuite_uses_psk( suite_info ) &&
873 ssl_conf_has_psk_or_cb( ssl->conf ) == 0 )
874 {
875 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no pre-shared key" ) );
876 return( 0 );
877 }
878 #endif
879
880 #if defined(MBEDTLS_X509_CRT_PARSE_C)
881 /*
882 * Final check: if ciphersuite requires us to have a
883 * certificate/key of a particular type:
884 * - select the appropriate certificate if we have one, or
885 * - try the next ciphersuite if we don't
886 * This must be done last since we modify the key_cert list.
887 */
888 if( ssl_pick_cert( ssl, suite_info ) != 0 )
889 {
890 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: "
891 "no suitable certificate" ) );
892 return( 0 );
893 }
894 #endif
895
896 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
897 /* If the ciphersuite requires signing, check whether
898 * a suitable hash algorithm is present. */
899 sig_type = mbedtls_ssl_get_ciphersuite_sig_alg( suite_info );
900 if( sig_type != MBEDTLS_PK_NONE &&
901 mbedtls_ssl_tls12_get_preferred_hash_for_sig_alg(
902 ssl, mbedtls_ssl_sig_from_pk_alg( sig_type ) ) == MBEDTLS_SSL_HASH_NONE )
903 {
904 MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no suitable hash algorithm "
905 "for signature algorithm %u", (unsigned) sig_type ) );
906 return( 0 );
907 }
908
909 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
910
911 *ciphersuite_info = suite_info;
912 return( 0 );
913 }
914
915 /* This function doesn't alert on errors that happen early during
916 ClientHello parsing because they might indicate that the client is
917 not talking SSL/TLS at all and would not understand our alert. */
918 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_client_hello(mbedtls_ssl_context * ssl)919 static int ssl_parse_client_hello( mbedtls_ssl_context *ssl )
920 {
921 int ret, got_common_suite;
922 size_t i, j;
923 size_t ciph_offset, comp_offset, ext_offset;
924 size_t msg_len, ciph_len, sess_len, comp_len, ext_len;
925 #if defined(MBEDTLS_SSL_PROTO_DTLS)
926 size_t cookie_offset, cookie_len;
927 #endif
928 unsigned char *buf, *p, *ext;
929 #if defined(MBEDTLS_SSL_RENEGOTIATION)
930 int renegotiation_info_seen = 0;
931 #endif
932 int handshake_failure = 0;
933 const int *ciphersuites;
934 const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
935
936 /* If there is no signature-algorithm extension present,
937 * we need to fall back to the default values for allowed
938 * signature-hash pairs. */
939 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
940 int sig_hash_alg_ext_present = 0;
941 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
942
943 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) );
944
945 int renegotiating;
946
947 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
948 read_record_header:
949 #endif
950 /*
951 * If renegotiating, then the input was read with mbedtls_ssl_read_record(),
952 * otherwise read it ourselves manually in order to support SSLv2
953 * ClientHello, which doesn't use the same record layer format.
954 */
955 renegotiating = 0;
956 #if defined(MBEDTLS_SSL_RENEGOTIATION)
957 renegotiating = ( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE );
958 #endif
959 if( !renegotiating )
960 {
961 if( ( ret = mbedtls_ssl_fetch_input( ssl, 5 ) ) != 0 )
962 {
963 /* No alert on a read error. */
964 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
965 return( ret );
966 }
967 }
968
969 buf = ssl->in_hdr;
970
971 MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, mbedtls_ssl_in_hdr_len( ssl ) );
972
973 /*
974 * TLS Client Hello
975 *
976 * Record layer:
977 * 0 . 0 message type
978 * 1 . 2 protocol version
979 * 3 . 11 DTLS: epoch + record sequence number
980 * 3 . 4 message length
981 */
982 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, message type: %d",
983 buf[0] ) );
984
985 if( buf[0] != MBEDTLS_SSL_MSG_HANDSHAKE )
986 {
987 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
988 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
989 }
990
991 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, message len.: %d",
992 ( ssl->in_len[0] << 8 ) | ssl->in_len[1] ) );
993
994 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, protocol version: [%d:%d]",
995 buf[1], buf[2] ) );
996
997 /* For DTLS if this is the initial handshake, remember the client sequence
998 * number to use it in our next message (RFC 6347 4.2.1) */
999 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1000 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM
1001 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1002 && ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE
1003 #endif
1004 )
1005 {
1006 /* Epoch should be 0 for initial handshakes */
1007 if( ssl->in_ctr[0] != 0 || ssl->in_ctr[1] != 0 )
1008 {
1009 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1010 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
1011 }
1012
1013 memcpy( &ssl->cur_out_ctr[2], ssl->in_ctr + 2,
1014 sizeof( ssl->cur_out_ctr ) - 2 );
1015
1016 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
1017 if( mbedtls_ssl_dtls_replay_check( ssl ) != 0 )
1018 {
1019 MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record, discarding" ) );
1020 ssl->next_record_offset = 0;
1021 ssl->in_left = 0;
1022 goto read_record_header;
1023 }
1024
1025 /* No MAC to check yet, so we can update right now */
1026 mbedtls_ssl_dtls_replay_update( ssl );
1027 #endif
1028 }
1029 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1030
1031 msg_len = ( ssl->in_len[0] << 8 ) | ssl->in_len[1];
1032
1033 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1034 if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
1035 {
1036 /* Set by mbedtls_ssl_read_record() */
1037 msg_len = ssl->in_hslen;
1038 }
1039 else
1040 #endif
1041 {
1042 if( msg_len > MBEDTLS_SSL_IN_CONTENT_LEN )
1043 {
1044 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1045 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
1046 }
1047
1048 if( ( ret = mbedtls_ssl_fetch_input( ssl,
1049 mbedtls_ssl_in_hdr_len( ssl ) + msg_len ) ) != 0 )
1050 {
1051 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
1052 return( ret );
1053 }
1054
1055 /* Done reading this record, get ready for the next one */
1056 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1057 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1058 ssl->next_record_offset = msg_len + mbedtls_ssl_in_hdr_len( ssl );
1059 else
1060 #endif
1061 ssl->in_left = 0;
1062 }
1063
1064 buf = ssl->in_msg;
1065
1066 MBEDTLS_SSL_DEBUG_BUF( 4, "record contents", buf, msg_len );
1067
1068 ssl->handshake->update_checksum( ssl, buf, msg_len );
1069
1070 /*
1071 * Handshake layer:
1072 * 0 . 0 handshake type
1073 * 1 . 3 handshake length
1074 * 4 . 5 DTLS only: message sequence number
1075 * 6 . 8 DTLS only: fragment offset
1076 * 9 . 11 DTLS only: fragment length
1077 */
1078 if( msg_len < mbedtls_ssl_hs_hdr_len( ssl ) )
1079 {
1080 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1081 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1082 }
1083
1084 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d", buf[0] ) );
1085
1086 if( buf[0] != MBEDTLS_SSL_HS_CLIENT_HELLO )
1087 {
1088 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1089 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
1090 }
1091 {
1092 size_t handshake_len = MBEDTLS_GET_UINT24_BE( buf, 1 );
1093 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %u",
1094 ( unsigned ) handshake_len ) );
1095
1096 /* The record layer has a record size limit of 2^14 - 1 and
1097 * fragmentation is not supported, so buf[1] should be zero. */
1098 if( buf[1] != 0 )
1099 {
1100 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message: %u != 0",
1101 (unsigned) buf[1] ) );
1102 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1103 }
1104
1105 /* We don't support fragmentation of ClientHello (yet?) */
1106 if( msg_len != mbedtls_ssl_hs_hdr_len( ssl ) + handshake_len )
1107 {
1108 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message: %u != %u + %u",
1109 (unsigned) msg_len,
1110 (unsigned) mbedtls_ssl_hs_hdr_len( ssl ),
1111 (unsigned) handshake_len ) );
1112 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1113 }
1114 }
1115
1116 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1117 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1118 {
1119 /*
1120 * Copy the client's handshake message_seq on initial handshakes,
1121 * check sequence number on renego.
1122 */
1123 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1124 if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
1125 {
1126 /* This couldn't be done in ssl_prepare_handshake_record() */
1127 unsigned int cli_msg_seq = ( ssl->in_msg[4] << 8 ) |
1128 ssl->in_msg[5];
1129
1130 if( cli_msg_seq != ssl->handshake->in_msg_seq )
1131 {
1132 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message_seq: "
1133 "%u (expected %u)", cli_msg_seq,
1134 ssl->handshake->in_msg_seq ) );
1135 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1136 }
1137
1138 ssl->handshake->in_msg_seq++;
1139 }
1140 else
1141 #endif
1142 {
1143 unsigned int cli_msg_seq = ( ssl->in_msg[4] << 8 ) |
1144 ssl->in_msg[5];
1145 ssl->handshake->out_msg_seq = cli_msg_seq;
1146 ssl->handshake->in_msg_seq = cli_msg_seq + 1;
1147 }
1148 {
1149 /*
1150 * For now we don't support fragmentation, so make sure
1151 * fragment_offset == 0 and fragment_length == length
1152 */
1153 size_t fragment_offset, fragment_length, length;
1154 fragment_offset = MBEDTLS_GET_UINT24_BE( ssl->in_msg, 6 );
1155 fragment_length = MBEDTLS_GET_UINT24_BE( ssl->in_msg, 9 );
1156 length = MBEDTLS_GET_UINT24_BE( ssl->in_msg, 1 );
1157 MBEDTLS_SSL_DEBUG_MSG(
1158 4, ( "fragment_offset=%u fragment_length=%u length=%u",
1159 (unsigned) fragment_offset, (unsigned) fragment_length,
1160 (unsigned) length ) );
1161 if( fragment_offset != 0 || length != fragment_length )
1162 {
1163 MBEDTLS_SSL_DEBUG_MSG( 1, ( "ClientHello fragmentation not supported" ) );
1164 return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
1165 }
1166 }
1167 }
1168 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1169
1170 buf += mbedtls_ssl_hs_hdr_len( ssl );
1171 msg_len -= mbedtls_ssl_hs_hdr_len( ssl );
1172
1173 /*
1174 * ClientHello layer:
1175 * 0 . 1 protocol version
1176 * 2 . 33 random bytes (starting with 4 bytes of Unix time)
1177 * 34 . 35 session id length (1 byte)
1178 * 35 . 34+x session id
1179 * 35+x . 35+x DTLS only: cookie length (1 byte)
1180 * 36+x . .. DTLS only: cookie
1181 * .. . .. ciphersuite list length (2 bytes)
1182 * .. . .. ciphersuite list
1183 * .. . .. compression alg. list length (1 byte)
1184 * .. . .. compression alg. list
1185 * .. . .. extensions length (2 bytes, optional)
1186 * .. . .. extensions (optional)
1187 */
1188
1189 /*
1190 * Minimal length (with everything empty and extensions omitted) is
1191 * 2 + 32 + 1 + 2 + 1 = 38 bytes. Check that first, so that we can
1192 * read at least up to session id length without worrying.
1193 */
1194 if( msg_len < 38 )
1195 {
1196 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1197 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1198 }
1199
1200 /*
1201 * Check and save the protocol version
1202 */
1203 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, version", buf, 2 );
1204
1205 ssl->tls_version = mbedtls_ssl_read_version( buf, ssl->conf->transport );
1206 ssl->session_negotiate->tls_version = ssl->tls_version;
1207
1208 if( ssl->tls_version != MBEDTLS_SSL_VERSION_TLS1_2 )
1209 {
1210 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server only supports TLS 1.2" ) );
1211 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1212 MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
1213 return( MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION );
1214 }
1215
1216 /*
1217 * Save client random (inc. Unix time)
1218 */
1219 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", buf + 2, 32 );
1220
1221 memcpy( ssl->handshake->randbytes, buf + 2, 32 );
1222
1223 /*
1224 * Check the session ID length and save session ID
1225 */
1226 sess_len = buf[34];
1227
1228 if( sess_len > sizeof( ssl->session_negotiate->id ) ||
1229 sess_len + 34 + 2 > msg_len ) /* 2 for cipherlist length field */
1230 {
1231 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1232 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1233 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1234 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1235 }
1236
1237 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 35, sess_len );
1238
1239 ssl->session_negotiate->id_len = sess_len;
1240 memset( ssl->session_negotiate->id, 0,
1241 sizeof( ssl->session_negotiate->id ) );
1242 memcpy( ssl->session_negotiate->id, buf + 35,
1243 ssl->session_negotiate->id_len );
1244
1245 /*
1246 * Check the cookie length and content
1247 */
1248 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1249 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1250 {
1251 cookie_offset = 35 + sess_len;
1252 cookie_len = buf[cookie_offset];
1253
1254 if( cookie_offset + 1 + cookie_len + 2 > msg_len )
1255 {
1256 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1257 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1258 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1259 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1260 }
1261
1262 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie",
1263 buf + cookie_offset + 1, cookie_len );
1264
1265 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
1266 if( ssl->conf->f_cookie_check != NULL
1267 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1268 && ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE
1269 #endif
1270 )
1271 {
1272 if( ssl->conf->f_cookie_check( ssl->conf->p_cookie,
1273 buf + cookie_offset + 1, cookie_len,
1274 ssl->cli_id, ssl->cli_id_len ) != 0 )
1275 {
1276 MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification failed" ) );
1277 ssl->handshake->verify_cookie_len = 1;
1278 }
1279 else
1280 {
1281 MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification passed" ) );
1282 ssl->handshake->verify_cookie_len = 0;
1283 }
1284 }
1285 else
1286 #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
1287 {
1288 /* We know we didn't send a cookie, so it should be empty */
1289 if( cookie_len != 0 )
1290 {
1291 /* This may be an attacker's probe, so don't send an alert */
1292 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1293 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1294 }
1295
1296 MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification skipped" ) );
1297 }
1298
1299 /*
1300 * Check the ciphersuitelist length (will be parsed later)
1301 */
1302 ciph_offset = cookie_offset + 1 + cookie_len;
1303 }
1304 else
1305 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1306 ciph_offset = 35 + sess_len;
1307
1308 ciph_len = ( buf[ciph_offset + 0] << 8 )
1309 | ( buf[ciph_offset + 1] );
1310
1311 if( ciph_len < 2 ||
1312 ciph_len + 2 + ciph_offset + 1 > msg_len || /* 1 for comp. alg. len */
1313 ( ciph_len % 2 ) != 0 )
1314 {
1315 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1316 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1317 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1318 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1319 }
1320
1321 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
1322 buf + ciph_offset + 2, ciph_len );
1323
1324 /*
1325 * Check the compression algorithm's length.
1326 * The list contents are ignored because implementing
1327 * MBEDTLS_SSL_COMPRESS_NULL is mandatory and is the only
1328 * option supported by Mbed TLS.
1329 */
1330 comp_offset = ciph_offset + 2 + ciph_len;
1331
1332 comp_len = buf[comp_offset];
1333
1334 if( comp_len < 1 ||
1335 comp_len > 16 ||
1336 comp_len + comp_offset + 1 > msg_len )
1337 {
1338 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1339 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1340 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1341 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1342 }
1343
1344 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, compression",
1345 buf + comp_offset + 1, comp_len );
1346
1347 /*
1348 * Check the extension length
1349 */
1350 ext_offset = comp_offset + 1 + comp_len;
1351 if( msg_len > ext_offset )
1352 {
1353 if( msg_len < ext_offset + 2 )
1354 {
1355 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1356 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1357 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1358 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1359 }
1360
1361 ext_len = ( buf[ext_offset + 0] << 8 )
1362 | ( buf[ext_offset + 1] );
1363
1364 if( msg_len != ext_offset + 2 + ext_len )
1365 {
1366 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1367 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1368 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1369 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1370 }
1371 }
1372 else
1373 ext_len = 0;
1374
1375 ext = buf + ext_offset + 2;
1376 MBEDTLS_SSL_DEBUG_BUF( 3, "client hello extensions", ext, ext_len );
1377
1378 while( ext_len != 0 )
1379 {
1380 unsigned int ext_id;
1381 unsigned int ext_size;
1382 if ( ext_len < 4 ) {
1383 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1384 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1385 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1386 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1387 }
1388 ext_id = ( ( ext[0] << 8 ) | ( ext[1] ) );
1389 ext_size = ( ( ext[2] << 8 ) | ( ext[3] ) );
1390
1391 if( ext_size + 4 > ext_len )
1392 {
1393 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
1394 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1395 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
1396 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
1397 }
1398 switch( ext_id )
1399 {
1400 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
1401 case MBEDTLS_TLS_EXT_SERVERNAME:
1402 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ServerName extension" ) );
1403 ret = mbedtls_ssl_parse_server_name_ext( ssl, ext + 4,
1404 ext + 4 + ext_size );
1405 if( ret != 0 )
1406 return( ret );
1407 break;
1408 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
1409
1410 case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO:
1411 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
1412 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1413 renegotiation_info_seen = 1;
1414 #endif
1415
1416 ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size );
1417 if( ret != 0 )
1418 return( ret );
1419 break;
1420
1421 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
1422 case MBEDTLS_TLS_EXT_SIG_ALG:
1423 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) );
1424
1425 ret = mbedtls_ssl_parse_sig_alg_ext( ssl, ext + 4, ext + 4 + ext_size );
1426 if( ret != 0 )
1427 return( ret );
1428
1429 sig_hash_alg_ext_present = 1;
1430 break;
1431 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
1432
1433 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
1434 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1435 case MBEDTLS_TLS_EXT_SUPPORTED_GROUPS:
1436 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported elliptic curves extension" ) );
1437
1438 ret = ssl_parse_supported_groups_ext( ssl, ext + 4, ext_size );
1439 if( ret != 0 )
1440 return( ret );
1441 break;
1442
1443 case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS:
1444 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported point formats extension" ) );
1445 ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT;
1446
1447 ret = ssl_parse_supported_point_formats( ssl, ext + 4, ext_size );
1448 if( ret != 0 )
1449 return( ret );
1450 break;
1451 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
1452 MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1453
1454 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1455 case MBEDTLS_TLS_EXT_ECJPAKE_KKPP:
1456 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ecjpake kkpp extension" ) );
1457
1458 ret = ssl_parse_ecjpake_kkpp( ssl, ext + 4, ext_size );
1459 if( ret != 0 )
1460 return( ret );
1461 break;
1462 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1463
1464 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
1465 case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH:
1466 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found max fragment length extension" ) );
1467
1468 ret = ssl_parse_max_fragment_length_ext( ssl, ext + 4, ext_size );
1469 if( ret != 0 )
1470 return( ret );
1471 break;
1472 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
1473
1474 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
1475 case MBEDTLS_TLS_EXT_CID:
1476 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found CID extension" ) );
1477
1478 ret = ssl_parse_cid_ext( ssl, ext + 4, ext_size );
1479 if( ret != 0 )
1480 return( ret );
1481 break;
1482 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
1483
1484 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
1485 case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
1486 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt then mac extension" ) );
1487
1488 ret = ssl_parse_encrypt_then_mac_ext( ssl, ext + 4, ext_size );
1489 if( ret != 0 )
1490 return( ret );
1491 break;
1492 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
1493
1494 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
1495 case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET:
1496 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extended master secret extension" ) );
1497
1498 ret = ssl_parse_extended_ms_ext( ssl, ext + 4, ext_size );
1499 if( ret != 0 )
1500 return( ret );
1501 break;
1502 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
1503
1504 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
1505 case MBEDTLS_TLS_EXT_SESSION_TICKET:
1506 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found session ticket extension" ) );
1507
1508 ret = ssl_parse_session_ticket_ext( ssl, ext + 4, ext_size );
1509 if( ret != 0 )
1510 return( ret );
1511 break;
1512 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
1513
1514 #if defined(MBEDTLS_SSL_ALPN)
1515 case MBEDTLS_TLS_EXT_ALPN:
1516 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
1517
1518 ret = mbedtls_ssl_parse_alpn_ext( ssl, ext + 4,
1519 ext + 4 + ext_size );
1520 if( ret != 0 )
1521 return( ret );
1522 break;
1523 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
1524
1525 #if defined(MBEDTLS_SSL_DTLS_SRTP)
1526 case MBEDTLS_TLS_EXT_USE_SRTP:
1527 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found use_srtp extension" ) );
1528
1529 ret = ssl_parse_use_srtp_ext( ssl, ext + 4, ext_size );
1530 if( ret != 0 )
1531 return( ret );
1532 break;
1533 #endif /* MBEDTLS_SSL_DTLS_SRTP */
1534
1535 default:
1536 MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %u (ignoring)",
1537 ext_id ) );
1538 }
1539
1540 ext_len -= 4 + ext_size;
1541 ext += 4 + ext_size;
1542 }
1543
1544 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
1545
1546 /*
1547 * Try to fall back to default hash SHA1 if the client
1548 * hasn't provided any preferred signature-hash combinations.
1549 */
1550 if( ! sig_hash_alg_ext_present )
1551 {
1552 uint16_t *received_sig_algs = ssl->handshake->received_sig_algs;
1553 const uint16_t default_sig_algs[] = {
1554 #if defined(MBEDTLS_ECDSA_C)
1555 MBEDTLS_SSL_TLS12_SIG_AND_HASH_ALG( MBEDTLS_SSL_SIG_ECDSA,
1556 MBEDTLS_SSL_HASH_SHA1 ),
1557 #endif
1558 #if defined(MBEDTLS_RSA_C)
1559 MBEDTLS_SSL_TLS12_SIG_AND_HASH_ALG( MBEDTLS_SSL_SIG_RSA,
1560 MBEDTLS_SSL_HASH_SHA1 ),
1561 #endif
1562 MBEDTLS_TLS_SIG_NONE
1563 };
1564
1565 #if defined(static_assert)
1566 static_assert( sizeof( default_sig_algs ) / sizeof( default_sig_algs[0] ) <=
1567 MBEDTLS_RECEIVED_SIG_ALGS_SIZE, "default_sig_algs is too big" );
1568 #endif
1569
1570 memcpy( received_sig_algs, default_sig_algs, sizeof( default_sig_algs ) );
1571 }
1572
1573 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
1574
1575 /*
1576 * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV
1577 */
1578 for( i = 0, p = buf + ciph_offset + 2; i < ciph_len; i += 2, p += 2 )
1579 {
1580 if( p[0] == 0 && p[1] == MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO )
1581 {
1582 MBEDTLS_SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
1583 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1584 if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
1585 {
1586 MBEDTLS_SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV "
1587 "during renegotiation" ) );
1588 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1589 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1590 return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
1591 }
1592 #endif
1593 ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
1594 break;
1595 }
1596 }
1597
1598 /*
1599 * Renegotiation security checks
1600 */
1601 if( ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_RENEGOTIATION &&
1602 ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE )
1603 {
1604 MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
1605 handshake_failure = 1;
1606 }
1607 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1608 else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
1609 ssl->secure_renegotiation == MBEDTLS_SSL_SECURE_RENEGOTIATION &&
1610 renegotiation_info_seen == 0 )
1611 {
1612 MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) );
1613 handshake_failure = 1;
1614 }
1615 else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
1616 ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
1617 ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION )
1618 {
1619 MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) );
1620 handshake_failure = 1;
1621 }
1622 else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
1623 ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
1624 renegotiation_info_seen == 1 )
1625 {
1626 MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
1627 handshake_failure = 1;
1628 }
1629 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1630
1631 if( handshake_failure == 1 )
1632 {
1633 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1634 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1635 return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
1636 }
1637
1638 /*
1639 * Server certification selection (after processing TLS extensions)
1640 */
1641 if( ssl->conf->f_cert_cb && ( ret = ssl->conf->f_cert_cb( ssl ) ) != 0 )
1642 {
1643 MBEDTLS_SSL_DEBUG_RET( 1, "f_cert_cb", ret );
1644 return( ret );
1645 }
1646 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
1647 ssl->handshake->sni_name = NULL;
1648 ssl->handshake->sni_name_len = 0;
1649 #endif
1650
1651 /*
1652 * Search for a matching ciphersuite
1653 * (At the end because we need information from the EC-based extensions
1654 * and certificate from the SNI callback triggered by the SNI extension
1655 * or certificate from server certificate selection callback.)
1656 */
1657 got_common_suite = 0;
1658 ciphersuites = ssl->conf->ciphersuite_list;
1659 ciphersuite_info = NULL;
1660
1661 if (ssl->conf->respect_cli_pref == MBEDTLS_SSL_SRV_CIPHERSUITE_ORDER_CLIENT)
1662 {
1663 for( j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2 )
1664 for( i = 0; ciphersuites[i] != 0; i++ )
1665 {
1666 if( MBEDTLS_GET_UINT16_BE(p, 0) != ciphersuites[i] )
1667 continue;
1668
1669 got_common_suite = 1;
1670
1671 if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i],
1672 &ciphersuite_info ) ) != 0 )
1673 return( ret );
1674
1675 if( ciphersuite_info != NULL )
1676 goto have_ciphersuite;
1677 }
1678 } else {
1679 for( i = 0; ciphersuites[i] != 0; i++ )
1680 for( j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2 )
1681 {
1682 if( MBEDTLS_GET_UINT16_BE(p, 0) != ciphersuites[i] )
1683 continue;
1684
1685 got_common_suite = 1;
1686
1687 if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i],
1688 &ciphersuite_info ) ) != 0 )
1689 return( ret );
1690
1691 if( ciphersuite_info != NULL )
1692 goto have_ciphersuite;
1693 }
1694 }
1695
1696 if( got_common_suite )
1697 {
1698 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, "
1699 "but none of them usable" ) );
1700 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1701 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1702 return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
1703 }
1704 else
1705 {
1706 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) );
1707 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
1708 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
1709 return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
1710 }
1711
1712 have_ciphersuite:
1713 MBEDTLS_SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) );
1714
1715 ssl->session_negotiate->ciphersuite = ciphersuites[i];
1716 ssl->handshake->ciphersuite_info = ciphersuite_info;
1717
1718 ssl->state++;
1719
1720 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1721 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1722 mbedtls_ssl_recv_flight_completed( ssl );
1723 #endif
1724
1725 /* Debugging-only output for testsuite */
1726 #if defined(MBEDTLS_DEBUG_C) && \
1727 defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
1728 mbedtls_pk_type_t sig_alg = mbedtls_ssl_get_ciphersuite_sig_alg( ciphersuite_info );
1729 if( sig_alg != MBEDTLS_PK_NONE )
1730 {
1731 unsigned int sig_hash = mbedtls_ssl_tls12_get_preferred_hash_for_sig_alg(
1732 ssl, mbedtls_ssl_sig_from_pk_alg( sig_alg ) );
1733 MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: %u",
1734 sig_hash ) );
1735 }
1736 else
1737 {
1738 MBEDTLS_SSL_DEBUG_MSG( 3, ( "no hash algorithm for signature algorithm "
1739 "%u - should not happen", (unsigned) sig_alg ) );
1740 }
1741 #endif
1742
1743 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client hello" ) );
1744
1745 return( 0 );
1746 }
1747
1748 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
ssl_write_cid_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)1749 static void ssl_write_cid_ext( mbedtls_ssl_context *ssl,
1750 unsigned char *buf,
1751 size_t *olen )
1752 {
1753 unsigned char *p = buf;
1754 size_t ext_len;
1755 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
1756
1757 *olen = 0;
1758
1759 /* Skip writing the extension if we don't want to use it or if
1760 * the client hasn't offered it. */
1761 if( ssl->handshake->cid_in_use == MBEDTLS_SSL_CID_DISABLED )
1762 return;
1763
1764 /* ssl->own_cid_len is at most MBEDTLS_SSL_CID_IN_LEN_MAX
1765 * which is at most 255, so the increment cannot overflow. */
1766 if( end < p || (size_t)( end - p ) < (unsigned)( ssl->own_cid_len + 5 ) )
1767 {
1768 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
1769 return;
1770 }
1771
1772 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding CID extension" ) );
1773
1774 /*
1775 * struct {
1776 * opaque cid<0..2^8-1>;
1777 * } ConnectionId;
1778 */
1779 MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_CID, p, 0 );
1780 p += 2;
1781 ext_len = (size_t) ssl->own_cid_len + 1;
1782 MBEDTLS_PUT_UINT16_BE( ext_len, p, 0 );
1783 p += 2;
1784
1785 *p++ = (uint8_t) ssl->own_cid_len;
1786 memcpy( p, ssl->own_cid, ssl->own_cid_len );
1787
1788 *olen = ssl->own_cid_len + 5;
1789 }
1790 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
1791
1792 #if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC_ETM)
ssl_write_encrypt_then_mac_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)1793 static void ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
1794 unsigned char *buf,
1795 size_t *olen )
1796 {
1797 unsigned char *p = buf;
1798 const mbedtls_ssl_ciphersuite_t *suite = NULL;
1799
1800 /*
1801 * RFC 7366: "If a server receives an encrypt-then-MAC request extension
1802 * from a client and then selects a stream or Authenticated Encryption
1803 * with Associated Data (AEAD) ciphersuite, it MUST NOT send an
1804 * encrypt-then-MAC response extension back to the client."
1805 */
1806 suite = mbedtls_ssl_ciphersuite_from_id(
1807 ssl->session_negotiate->ciphersuite );
1808 if( suite == NULL )
1809 ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_DISABLED;
1810 else
1811 {
1812 mbedtls_ssl_mode_t ssl_mode =
1813 mbedtls_ssl_get_mode_from_ciphersuite(
1814 ssl->session_negotiate->encrypt_then_mac,
1815 suite );
1816
1817 if( ssl_mode != MBEDTLS_SSL_MODE_CBC_ETM )
1818 ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_DISABLED;
1819 }
1820
1821 if( ssl->session_negotiate->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED )
1822 {
1823 *olen = 0;
1824 return;
1825 }
1826
1827 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding encrypt then mac extension" ) );
1828
1829 MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC, p, 0 );
1830 p += 2;
1831
1832 *p++ = 0x00;
1833 *p++ = 0x00;
1834
1835 *olen = 4;
1836 }
1837 #endif /* MBEDTLS_SSL_SOME_SUITES_USE_CBC_ETM */
1838
1839 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
ssl_write_extended_ms_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)1840 static void ssl_write_extended_ms_ext( mbedtls_ssl_context *ssl,
1841 unsigned char *buf,
1842 size_t *olen )
1843 {
1844 unsigned char *p = buf;
1845
1846 if( ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED )
1847 {
1848 *olen = 0;
1849 return;
1850 }
1851
1852 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding extended master secret "
1853 "extension" ) );
1854
1855 MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET, p, 0 );
1856 p += 2;
1857
1858 *p++ = 0x00;
1859 *p++ = 0x00;
1860
1861 *olen = 4;
1862 }
1863 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
1864
1865 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
ssl_write_session_ticket_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)1866 static void ssl_write_session_ticket_ext( mbedtls_ssl_context *ssl,
1867 unsigned char *buf,
1868 size_t *olen )
1869 {
1870 unsigned char *p = buf;
1871
1872 if( ssl->handshake->new_session_ticket == 0 )
1873 {
1874 *olen = 0;
1875 return;
1876 }
1877
1878 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding session ticket extension" ) );
1879
1880 MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_SESSION_TICKET, p, 0 );
1881 p += 2;
1882
1883 *p++ = 0x00;
1884 *p++ = 0x00;
1885
1886 *olen = 4;
1887 }
1888 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
1889
ssl_write_renegotiation_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)1890 static void ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl,
1891 unsigned char *buf,
1892 size_t *olen )
1893 {
1894 unsigned char *p = buf;
1895
1896 if( ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_RENEGOTIATION )
1897 {
1898 *olen = 0;
1899 return;
1900 }
1901
1902 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, secure renegotiation extension" ) );
1903
1904 MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO, p, 0 );
1905 p += 2;
1906
1907 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1908 if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
1909 {
1910 *p++ = 0x00;
1911 *p++ = ( ssl->verify_data_len * 2 + 1 ) & 0xFF;
1912 *p++ = ssl->verify_data_len * 2 & 0xFF;
1913
1914 memcpy( p, ssl->peer_verify_data, ssl->verify_data_len );
1915 p += ssl->verify_data_len;
1916 memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
1917 p += ssl->verify_data_len;
1918 }
1919 else
1920 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1921 {
1922 *p++ = 0x00;
1923 *p++ = 0x01;
1924 *p++ = 0x00;
1925 }
1926
1927 *olen = p - buf;
1928 }
1929
1930 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
ssl_write_max_fragment_length_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)1931 static void ssl_write_max_fragment_length_ext( mbedtls_ssl_context *ssl,
1932 unsigned char *buf,
1933 size_t *olen )
1934 {
1935 unsigned char *p = buf;
1936
1937 if( ssl->session_negotiate->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE )
1938 {
1939 *olen = 0;
1940 return;
1941 }
1942
1943 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, max_fragment_length extension" ) );
1944
1945 MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH, p, 0 );
1946 p += 2;
1947
1948 *p++ = 0x00;
1949 *p++ = 1;
1950
1951 *p++ = ssl->session_negotiate->mfl_code;
1952
1953 *olen = 5;
1954 }
1955 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
1956
1957 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
1958 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl_write_supported_point_formats_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)1959 static void ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl,
1960 unsigned char *buf,
1961 size_t *olen )
1962 {
1963 unsigned char *p = buf;
1964 ((void) ssl);
1965
1966 if( ( ssl->handshake->cli_exts &
1967 MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT ) == 0 )
1968 {
1969 *olen = 0;
1970 return;
1971 }
1972
1973 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, supported_point_formats extension" ) );
1974
1975 MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS, p, 0 );
1976 p += 2;
1977
1978 *p++ = 0x00;
1979 *p++ = 2;
1980
1981 *p++ = 1;
1982 *p++ = MBEDTLS_ECP_PF_UNCOMPRESSED;
1983
1984 *olen = 6;
1985 }
1986 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1987
1988 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl_write_ecjpake_kkpp_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)1989 static void ssl_write_ecjpake_kkpp_ext( mbedtls_ssl_context *ssl,
1990 unsigned char *buf,
1991 size_t *olen )
1992 {
1993 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
1994 unsigned char *p = buf;
1995 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
1996 size_t kkpp_len;
1997
1998 *olen = 0;
1999
2000 /* Skip costly computation if not needed */
2001 if( ssl->handshake->ciphersuite_info->key_exchange !=
2002 MBEDTLS_KEY_EXCHANGE_ECJPAKE )
2003 return;
2004
2005 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, ecjpake kkpp extension" ) );
2006
2007 if( end - p < 4 )
2008 {
2009 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
2010 return;
2011 }
2012
2013 MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_ECJPAKE_KKPP, p, 0 );
2014 p += 2;
2015
2016 #if defined(MBEDTLS_USE_PSA_CRYPTO)
2017 ret = mbedtls_psa_ecjpake_write_round( &ssl->handshake->psa_pake_ctx,
2018 p + 2, end - p - 2, &kkpp_len,
2019 MBEDTLS_ECJPAKE_ROUND_ONE );
2020 if ( ret != 0 )
2021 {
2022 psa_destroy_key( ssl->handshake->psa_pake_password );
2023 psa_pake_abort( &ssl->handshake->psa_pake_ctx );
2024 MBEDTLS_SSL_DEBUG_RET( 1 , "psa_pake_output", ret );
2025 return;
2026 }
2027 #else
2028 ret = mbedtls_ecjpake_write_round_one( &ssl->handshake->ecjpake_ctx,
2029 p + 2, end - p - 2, &kkpp_len,
2030 ssl->conf->f_rng, ssl->conf->p_rng );
2031 if( ret != 0 )
2032 {
2033 MBEDTLS_SSL_DEBUG_RET( 1 , "mbedtls_ecjpake_write_round_one", ret );
2034 return;
2035 }
2036 #endif /* MBEDTLS_USE_PSA_CRYPTO */
2037
2038 MBEDTLS_PUT_UINT16_BE( kkpp_len, p, 0 );
2039 p += 2;
2040
2041 *olen = kkpp_len + 4;
2042 }
2043 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
2044
2045 #if defined(MBEDTLS_SSL_DTLS_SRTP ) && defined(MBEDTLS_SSL_PROTO_DTLS)
ssl_write_use_srtp_ext(mbedtls_ssl_context * ssl,unsigned char * buf,size_t * olen)2046 static void ssl_write_use_srtp_ext( mbedtls_ssl_context *ssl,
2047 unsigned char *buf,
2048 size_t *olen )
2049 {
2050 size_t mki_len = 0, ext_len = 0;
2051 uint16_t profile_value = 0;
2052 const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
2053
2054 *olen = 0;
2055
2056 if( ( ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM ) ||
2057 ( ssl->dtls_srtp_info.chosen_dtls_srtp_profile == MBEDTLS_TLS_SRTP_UNSET ) )
2058 {
2059 return;
2060 }
2061
2062 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding use_srtp extension" ) );
2063
2064 if( ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED )
2065 {
2066 mki_len = ssl->dtls_srtp_info.mki_len;
2067 }
2068
2069 /* The extension total size is 9 bytes :
2070 * - 2 bytes for the extension tag
2071 * - 2 bytes for the total size
2072 * - 2 bytes for the protection profile length
2073 * - 2 bytes for the protection profile
2074 * - 1 byte for the mki length
2075 * + the actual mki length
2076 * Check we have enough room in the output buffer */
2077 if( (size_t)( end - buf ) < mki_len + 9 )
2078 {
2079 MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
2080 return;
2081 }
2082
2083 /* extension */
2084 MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_USE_SRTP, buf, 0 );
2085 /*
2086 * total length 5 and mki value: only one profile(2 bytes)
2087 * and length(2 bytes) and srtp_mki )
2088 */
2089 ext_len = 5 + mki_len;
2090 MBEDTLS_PUT_UINT16_BE( ext_len, buf, 2 );
2091
2092 /* protection profile length: 2 */
2093 buf[4] = 0x00;
2094 buf[5] = 0x02;
2095 profile_value = mbedtls_ssl_check_srtp_profile_value(
2096 ssl->dtls_srtp_info.chosen_dtls_srtp_profile );
2097 if( profile_value != MBEDTLS_TLS_SRTP_UNSET )
2098 {
2099 MBEDTLS_PUT_UINT16_BE( profile_value, buf, 6 );
2100 }
2101 else
2102 {
2103 MBEDTLS_SSL_DEBUG_MSG( 1, ( "use_srtp extension invalid profile" ) );
2104 return;
2105 }
2106
2107 buf[8] = mki_len & 0xFF;
2108 memcpy( &buf[9], ssl->dtls_srtp_info.mki_value, mki_len );
2109
2110 *olen = 9 + mki_len;
2111 }
2112 #endif /* MBEDTLS_SSL_DTLS_SRTP */
2113
2114 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
2115 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_write_hello_verify_request(mbedtls_ssl_context * ssl)2116 static int ssl_write_hello_verify_request( mbedtls_ssl_context *ssl )
2117 {
2118 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2119 unsigned char *p = ssl->out_msg + 4;
2120 unsigned char *cookie_len_byte;
2121
2122 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write hello verify request" ) );
2123
2124 /*
2125 * struct {
2126 * ProtocolVersion server_version;
2127 * opaque cookie<0..2^8-1>;
2128 * } HelloVerifyRequest;
2129 */
2130
2131 /* The RFC is not clear on this point, but sending the actual negotiated
2132 * version looks like the most interoperable thing to do. */
2133 mbedtls_ssl_write_version( p, ssl->conf->transport, ssl->tls_version );
2134 MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
2135 p += 2;
2136
2137 /* If we get here, f_cookie_check is not null */
2138 if( ssl->conf->f_cookie_write == NULL )
2139 {
2140 MBEDTLS_SSL_DEBUG_MSG( 1, ( "inconsistent cookie callbacks" ) );
2141 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2142 }
2143
2144 /* Skip length byte until we know the length */
2145 cookie_len_byte = p++;
2146
2147 if( ( ret = ssl->conf->f_cookie_write( ssl->conf->p_cookie,
2148 &p, ssl->out_buf + MBEDTLS_SSL_OUT_BUFFER_LEN,
2149 ssl->cli_id, ssl->cli_id_len ) ) != 0 )
2150 {
2151 MBEDTLS_SSL_DEBUG_RET( 1, "f_cookie_write", ret );
2152 return( ret );
2153 }
2154
2155 *cookie_len_byte = (unsigned char)( p - ( cookie_len_byte + 1 ) );
2156
2157 MBEDTLS_SSL_DEBUG_BUF( 3, "cookie sent", cookie_len_byte + 1, *cookie_len_byte );
2158
2159 ssl->out_msglen = p - ssl->out_msg;
2160 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
2161 ssl->out_msg[0] = MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST;
2162
2163 ssl->state = MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT;
2164
2165 if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
2166 {
2167 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
2168 return( ret );
2169 }
2170
2171 #if defined(MBEDTLS_SSL_PROTO_DTLS)
2172 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
2173 ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
2174 {
2175 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flight_transmit", ret );
2176 return( ret );
2177 }
2178 #endif /* MBEDTLS_SSL_PROTO_DTLS */
2179
2180 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write hello verify request" ) );
2181
2182 return( 0 );
2183 }
2184 #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
2185
ssl_handle_id_based_session_resumption(mbedtls_ssl_context * ssl)2186 static void ssl_handle_id_based_session_resumption( mbedtls_ssl_context *ssl )
2187 {
2188 int ret;
2189 mbedtls_ssl_session session_tmp;
2190 mbedtls_ssl_session * const session = ssl->session_negotiate;
2191
2192 /* Resume is 0 by default, see ssl_handshake_init().
2193 * It may be already set to 1 by ssl_parse_session_ticket_ext(). */
2194 if( ssl->handshake->resume == 1 )
2195 return;
2196 if( session->id_len == 0 )
2197 return;
2198 if( ssl->conf->f_get_cache == NULL )
2199 return;
2200 #if defined(MBEDTLS_SSL_RENEGOTIATION)
2201 if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
2202 return;
2203 #endif
2204
2205 mbedtls_ssl_session_init( &session_tmp );
2206
2207 ret = ssl->conf->f_get_cache( ssl->conf->p_cache,
2208 session->id,
2209 session->id_len,
2210 &session_tmp );
2211 if( ret != 0 )
2212 goto exit;
2213
2214 if( session->ciphersuite != session_tmp.ciphersuite )
2215 {
2216 /* Mismatch between cached and negotiated session */
2217 goto exit;
2218 }
2219
2220 /* Move semantics */
2221 mbedtls_ssl_session_free( session );
2222 *session = session_tmp;
2223 memset( &session_tmp, 0, sizeof( session_tmp ) );
2224
2225 MBEDTLS_SSL_DEBUG_MSG( 3, ( "session successfully restored from cache" ) );
2226 ssl->handshake->resume = 1;
2227
2228 exit:
2229
2230 mbedtls_ssl_session_free( &session_tmp );
2231 }
2232
2233 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_write_server_hello(mbedtls_ssl_context * ssl)2234 static int ssl_write_server_hello( mbedtls_ssl_context *ssl )
2235 {
2236 #if defined(MBEDTLS_HAVE_TIME)
2237 mbedtls_time_t t;
2238 #endif
2239 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2240 size_t olen, ext_len = 0, n;
2241 unsigned char *buf, *p;
2242
2243 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server hello" ) );
2244
2245 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
2246 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
2247 ssl->handshake->verify_cookie_len != 0 )
2248 {
2249 MBEDTLS_SSL_DEBUG_MSG( 2, ( "client hello was not authenticated" ) );
2250 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello" ) );
2251
2252 return( ssl_write_hello_verify_request( ssl ) );
2253 }
2254 #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
2255
2256 if( ssl->conf->f_rng == NULL )
2257 {
2258 MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided") );
2259 return( MBEDTLS_ERR_SSL_NO_RNG );
2260 }
2261
2262 /*
2263 * 0 . 0 handshake type
2264 * 1 . 3 handshake length
2265 * 4 . 5 protocol version
2266 * 6 . 9 UNIX time()
2267 * 10 . 37 random bytes
2268 */
2269 buf = ssl->out_msg;
2270 p = buf + 4;
2271
2272 mbedtls_ssl_write_version( p, ssl->conf->transport, ssl->tls_version );
2273 p += 2;
2274
2275 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen version: [%d:%d]",
2276 buf[4], buf[5] ) );
2277
2278 #if defined(MBEDTLS_HAVE_TIME)
2279 t = mbedtls_time( NULL );
2280 MBEDTLS_PUT_UINT32_BE( t, p, 0 );
2281 p += 4;
2282
2283 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %" MBEDTLS_PRINTF_LONGLONG,
2284 (long long) t ) );
2285 #else
2286 if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 4 ) ) != 0 )
2287 return( ret );
2288
2289 p += 4;
2290 #endif /* MBEDTLS_HAVE_TIME */
2291
2292 if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 28 ) ) != 0 )
2293 return( ret );
2294
2295 p += 28;
2296
2297 memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 );
2298
2299 MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 );
2300
2301 ssl_handle_id_based_session_resumption( ssl );
2302
2303 if( ssl->handshake->resume == 0 )
2304 {
2305 /*
2306 * New session, create a new session id,
2307 * unless we're about to issue a session ticket
2308 */
2309 ssl->state++;
2310
2311 #if defined(MBEDTLS_HAVE_TIME)
2312 ssl->session_negotiate->start = mbedtls_time( NULL );
2313 #endif
2314
2315 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
2316 if( ssl->handshake->new_session_ticket != 0 )
2317 {
2318 ssl->session_negotiate->id_len = n = 0;
2319 memset( ssl->session_negotiate->id, 0, 32 );
2320 }
2321 else
2322 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
2323 {
2324 ssl->session_negotiate->id_len = n = 32;
2325 if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, ssl->session_negotiate->id,
2326 n ) ) != 0 )
2327 return( ret );
2328 }
2329 }
2330 else
2331 {
2332 /*
2333 * Resuming a session
2334 */
2335 n = ssl->session_negotiate->id_len;
2336 ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
2337
2338 if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
2339 {
2340 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
2341 return( ret );
2342 }
2343 }
2344
2345 /*
2346 * 38 . 38 session id length
2347 * 39 . 38+n session id
2348 * 39+n . 40+n chosen ciphersuite
2349 * 41+n . 41+n chosen compression alg.
2350 * 42+n . 43+n extensions length
2351 * 44+n . 43+n+m extensions
2352 */
2353 *p++ = (unsigned char) ssl->session_negotiate->id_len;
2354 memcpy( p, ssl->session_negotiate->id, ssl->session_negotiate->id_len );
2355 p += ssl->session_negotiate->id_len;
2356
2357 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %" MBEDTLS_PRINTF_SIZET, n ) );
2358 MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, session id", buf + 39, n );
2359 MBEDTLS_SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
2360 ssl->handshake->resume ? "a" : "no" ) );
2361
2362 MBEDTLS_PUT_UINT16_BE( ssl->session_negotiate->ciphersuite, p, 0 );
2363 p += 2;
2364 *p++ = MBEDTLS_BYTE_0( MBEDTLS_SSL_COMPRESS_NULL );
2365
2366 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %s",
2367 mbedtls_ssl_get_ciphersuite_name( ssl->session_negotiate->ciphersuite ) ) );
2368 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: 0x%02X",
2369 (unsigned int) MBEDTLS_SSL_COMPRESS_NULL ) );
2370
2371 /*
2372 * First write extensions, then the total length
2373 */
2374 ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen );
2375 ext_len += olen;
2376
2377 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
2378 ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen );
2379 ext_len += olen;
2380 #endif
2381
2382 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
2383 ssl_write_cid_ext( ssl, p + 2 + ext_len, &olen );
2384 ext_len += olen;
2385 #endif
2386
2387 #if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC_ETM)
2388 ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len, &olen );
2389 ext_len += olen;
2390 #endif
2391
2392 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
2393 ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen );
2394 ext_len += olen;
2395 #endif
2396
2397 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
2398 ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
2399 ext_len += olen;
2400 #endif
2401
2402 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
2403 defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
2404 const mbedtls_ssl_ciphersuite_t *suite =
2405 mbedtls_ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite );
2406 if ( suite != NULL && mbedtls_ssl_ciphersuite_uses_ec( suite) )
2407 {
2408 ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
2409 ext_len += olen;
2410 }
2411 #endif
2412
2413 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
2414 ssl_write_ecjpake_kkpp_ext( ssl, p + 2 + ext_len, &olen );
2415 ext_len += olen;
2416 #endif
2417
2418 #if defined(MBEDTLS_SSL_ALPN)
2419 unsigned char *end = buf + MBEDTLS_SSL_OUT_CONTENT_LEN - 4;
2420 if( ( ret = mbedtls_ssl_write_alpn_ext( ssl, p + 2 + ext_len, end, &olen ) )
2421 != 0 )
2422 return ret;
2423
2424 ext_len += olen;
2425 #endif
2426
2427 #if defined(MBEDTLS_SSL_DTLS_SRTP)
2428 ssl_write_use_srtp_ext( ssl, p + 2 + ext_len, &olen );
2429 ext_len += olen;
2430 #endif
2431
2432 MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, total extension length: %" MBEDTLS_PRINTF_SIZET,
2433 ext_len ) );
2434
2435 if( ext_len > 0 )
2436 {
2437 MBEDTLS_PUT_UINT16_BE( ext_len, p, 0 );
2438 p += 2 + ext_len;
2439 }
2440
2441 ssl->out_msglen = p - buf;
2442 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
2443 ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_HELLO;
2444
2445 ret = mbedtls_ssl_write_handshake_msg( ssl );
2446
2447 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello" ) );
2448
2449 return( ret );
2450 }
2451
2452 #if !defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED)
2453 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_write_certificate_request(mbedtls_ssl_context * ssl)2454 static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
2455 {
2456 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
2457 ssl->handshake->ciphersuite_info;
2458
2459 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
2460
2461 if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
2462 {
2463 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
2464 ssl->state++;
2465 return( 0 );
2466 }
2467
2468 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
2469 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
2470 }
2471 #else /* !MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */
2472 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_write_certificate_request(mbedtls_ssl_context * ssl)2473 static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
2474 {
2475 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
2476 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
2477 ssl->handshake->ciphersuite_info;
2478 uint16_t dn_size, total_dn_size; /* excluding length bytes */
2479 size_t ct_len, sa_len; /* including length bytes */
2480 unsigned char *buf, *p;
2481 const unsigned char * const end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
2482 const mbedtls_x509_crt *crt;
2483 int authmode;
2484
2485 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
2486
2487 ssl->state++;
2488
2489 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
2490 if( ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET )
2491 authmode = ssl->handshake->sni_authmode;
2492 else
2493 #endif
2494 authmode = ssl->conf->authmode;
2495
2496 if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) ||
2497 authmode == MBEDTLS_SSL_VERIFY_NONE )
2498 {
2499 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
2500 return( 0 );
2501 }
2502
2503 /*
2504 * 0 . 0 handshake type
2505 * 1 . 3 handshake length
2506 * 4 . 4 cert type count
2507 * 5 .. m-1 cert types
2508 * m .. m+1 sig alg length (TLS 1.2 only)
2509 * m+1 .. n-1 SignatureAndHashAlgorithms (TLS 1.2 only)
2510 * n .. n+1 length of all DNs
2511 * n+2 .. n+3 length of DN 1
2512 * n+4 .. ... Distinguished Name #1
2513 * ... .. ... length of DN 2, etc.
2514 */
2515 buf = ssl->out_msg;
2516 p = buf + 4;
2517
2518 /*
2519 * Supported certificate types
2520 *
2521 * ClientCertificateType certificate_types<1..2^8-1>;
2522 * enum { (255) } ClientCertificateType;
2523 */
2524 ct_len = 0;
2525
2526 #if defined(MBEDTLS_RSA_C)
2527 p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_RSA_SIGN;
2528 #endif
2529 #if defined(MBEDTLS_ECDSA_C)
2530 p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_ECDSA_SIGN;
2531 #endif
2532
2533 p[0] = (unsigned char) ct_len++;
2534 p += ct_len;
2535
2536 sa_len = 0;
2537
2538 /*
2539 * Add signature_algorithms for verify (TLS 1.2)
2540 *
2541 * SignatureAndHashAlgorithm supported_signature_algorithms<2..2^16-2>;
2542 *
2543 * struct {
2544 * HashAlgorithm hash;
2545 * SignatureAlgorithm signature;
2546 * } SignatureAndHashAlgorithm;
2547 *
2548 * enum { (255) } HashAlgorithm;
2549 * enum { (255) } SignatureAlgorithm;
2550 */
2551 const uint16_t *sig_alg = mbedtls_ssl_get_sig_algs( ssl );
2552 if( sig_alg == NULL )
2553 return( MBEDTLS_ERR_SSL_BAD_CONFIG );
2554
2555 for( ; *sig_alg != MBEDTLS_TLS_SIG_NONE; sig_alg++ )
2556 {
2557 unsigned char hash = MBEDTLS_BYTE_1( *sig_alg );
2558
2559 if( mbedtls_ssl_set_calc_verify_md( ssl, hash ) )
2560 continue;
2561 if( ! mbedtls_ssl_sig_alg_is_supported( ssl, *sig_alg ) )
2562 continue;
2563
2564 /* Write elements at offsets starting from 1 (offset 0 is for the
2565 * length). Thus the offset of each element is the length of the
2566 * partial list including that element. */
2567 sa_len += 2;
2568 MBEDTLS_PUT_UINT16_BE( *sig_alg, p, sa_len );
2569
2570 }
2571
2572 /* Fill in list length. */
2573 MBEDTLS_PUT_UINT16_BE( sa_len, p, 0 );
2574 sa_len += 2;
2575 p += sa_len;
2576
2577 /*
2578 * DistinguishedName certificate_authorities<0..2^16-1>;
2579 * opaque DistinguishedName<1..2^16-1>;
2580 */
2581 p += 2;
2582
2583 total_dn_size = 0;
2584
2585 if( ssl->conf->cert_req_ca_list == MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED )
2586 {
2587 /* NOTE: If trusted certificates are provisioned
2588 * via a CA callback (configured through
2589 * `mbedtls_ssl_conf_ca_cb()`, then the
2590 * CertificateRequest is currently left empty. */
2591
2592 #if defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED)
2593 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
2594 if( ssl->handshake->dn_hints != NULL )
2595 crt = ssl->handshake->dn_hints;
2596 else
2597 #endif
2598 if( ssl->conf->dn_hints != NULL )
2599 crt = ssl->conf->dn_hints;
2600 else
2601 #endif
2602 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
2603 if( ssl->handshake->sni_ca_chain != NULL )
2604 crt = ssl->handshake->sni_ca_chain;
2605 else
2606 #endif
2607 crt = ssl->conf->ca_chain;
2608
2609 while( crt != NULL && crt->version != 0 )
2610 {
2611 /* It follows from RFC 5280 A.1 that this length
2612 * can be represented in at most 11 bits. */
2613 dn_size = (uint16_t) crt->subject_raw.len;
2614
2615 if( end < p || (size_t)( end - p ) < 2 + (size_t) dn_size )
2616 {
2617 MBEDTLS_SSL_DEBUG_MSG( 1, ( "skipping CAs: buffer too short" ) );
2618 break;
2619 }
2620
2621 MBEDTLS_PUT_UINT16_BE( dn_size, p, 0 );
2622 p += 2;
2623 memcpy( p, crt->subject_raw.p, dn_size );
2624 p += dn_size;
2625
2626 MBEDTLS_SSL_DEBUG_BUF( 3, "requested DN", p - dn_size, dn_size );
2627
2628 total_dn_size += 2 + dn_size;
2629 crt = crt->next;
2630 }
2631 }
2632
2633 ssl->out_msglen = p - buf;
2634 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
2635 ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE_REQUEST;
2636 MBEDTLS_PUT_UINT16_BE( total_dn_size, ssl->out_msg, 4 + ct_len + sa_len );
2637
2638 ret = mbedtls_ssl_write_handshake_msg( ssl );
2639
2640 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) );
2641
2642 return( ret );
2643 }
2644 #endif /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */
2645
2646 #if defined(MBEDTLS_USE_PSA_CRYPTO) && \
2647 ( defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
2648 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) )
2649 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_get_ecdh_params_from_cert(mbedtls_ssl_context * ssl)2650 static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
2651 {
2652 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2653 psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
2654 unsigned char buf[
2655 PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)];
2656 psa_key_attributes_t key_attributes = PSA_KEY_ATTRIBUTES_INIT;
2657 size_t ecdh_bits = 0;
2658 size_t key_len;
2659 mbedtls_pk_context *pk;
2660 mbedtls_ecp_keypair *key;
2661
2662 pk = mbedtls_ssl_own_key( ssl );
2663
2664 if( pk == NULL )
2665 return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
2666
2667 switch( mbedtls_pk_get_type( pk ) )
2668 {
2669 case MBEDTLS_PK_OPAQUE:
2670 if( ! mbedtls_pk_can_do( pk, MBEDTLS_PK_ECKEY ) )
2671 return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
2672
2673 ssl->handshake->ecdh_psa_privkey =
2674 *( (mbedtls_svc_key_id_t*) pk->pk_ctx );
2675
2676 /* Key should not be destroyed in the TLS library */
2677 ssl->handshake->ecdh_psa_privkey_is_external = 1;
2678
2679 status = psa_get_key_attributes( ssl->handshake->ecdh_psa_privkey,
2680 &key_attributes );
2681 if( status != PSA_SUCCESS)
2682 {
2683 ssl->handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
2684 return( psa_ssl_status_to_mbedtls( status ) );
2685 }
2686
2687 ssl->handshake->ecdh_psa_type = psa_get_key_type( &key_attributes );
2688 ssl->handshake->ecdh_bits = psa_get_key_bits( &key_attributes );
2689
2690 psa_reset_key_attributes( &key_attributes );
2691
2692 ret = 0;
2693 break;
2694 case MBEDTLS_PK_ECKEY:
2695 case MBEDTLS_PK_ECKEY_DH:
2696 case MBEDTLS_PK_ECDSA:
2697 key = mbedtls_pk_ec( *pk );
2698 if( key == NULL )
2699 return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
2700
2701 /* Convert EC group to PSA key type. */
2702 if( ( ssl->handshake->ecdh_psa_type =
2703 mbedtls_ecc_group_to_psa( key->grp.id,
2704 &ecdh_bits ) ) == 0 )
2705 {
2706 return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
2707 }
2708
2709 ssl->handshake->ecdh_bits = ecdh_bits;
2710
2711 key_attributes = psa_key_attributes_init();
2712 psa_set_key_usage_flags( &key_attributes, PSA_KEY_USAGE_DERIVE );
2713 psa_set_key_algorithm( &key_attributes, PSA_ALG_ECDH );
2714 psa_set_key_type( &key_attributes,
2715 PSA_KEY_TYPE_ECC_KEY_PAIR( ssl->handshake->ecdh_psa_type ) );
2716 psa_set_key_bits( &key_attributes, ssl->handshake->ecdh_bits );
2717
2718 key_len = PSA_BITS_TO_BYTES( key->grp.pbits );
2719 ret = mbedtls_ecp_write_key( key, buf, key_len );
2720 if( ret != 0 )
2721 goto cleanup;
2722
2723 status = psa_import_key( &key_attributes, buf, key_len,
2724 &ssl->handshake->ecdh_psa_privkey );
2725 if( status != PSA_SUCCESS )
2726 {
2727 ret = psa_ssl_status_to_mbedtls( status );
2728 goto cleanup;
2729 }
2730
2731 ret = 0;
2732 break;
2733 default:
2734 ret = MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH;
2735 }
2736
2737 cleanup:
2738 mbedtls_platform_zeroize( buf, sizeof( buf ) );
2739
2740 return( ret );
2741 }
2742 #elif defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
2743 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
2744 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_get_ecdh_params_from_cert(mbedtls_ssl_context * ssl)2745 static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
2746 {
2747 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2748
2749 const mbedtls_pk_context *private_key = mbedtls_ssl_own_key( ssl );
2750 if( private_key == NULL)
2751 {
2752 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no server private key" ) );
2753 return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
2754 }
2755
2756 if( ! mbedtls_pk_can_do( private_key, MBEDTLS_PK_ECKEY ) )
2757 {
2758 MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
2759 return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
2760 }
2761
2762 if( ( ret = mbedtls_ecdh_get_params( &ssl->handshake->ecdh_ctx,
2763 mbedtls_pk_ec( *mbedtls_ssl_own_key( ssl ) ),
2764 MBEDTLS_ECDH_OURS ) ) != 0 )
2765 {
2766 MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_get_params" ), ret );
2767 return( ret );
2768 }
2769
2770 return( 0 );
2771 }
2772 #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
2773 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
2774
2775 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) && \
2776 defined(MBEDTLS_SSL_ASYNC_PRIVATE)
2777 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_resume_server_key_exchange(mbedtls_ssl_context * ssl,size_t * signature_len)2778 static int ssl_resume_server_key_exchange( mbedtls_ssl_context *ssl,
2779 size_t *signature_len )
2780 {
2781 /* Append the signature to ssl->out_msg, leaving 2 bytes for the
2782 * signature length which will be added in ssl_write_server_key_exchange
2783 * after the call to ssl_prepare_server_key_exchange.
2784 * ssl_write_server_key_exchange also takes care of incrementing
2785 * ssl->out_msglen. */
2786 unsigned char *sig_start = ssl->out_msg + ssl->out_msglen + 2;
2787 size_t sig_max_len = ( ssl->out_buf + MBEDTLS_SSL_OUT_CONTENT_LEN
2788 - sig_start );
2789 int ret = ssl->conf->f_async_resume( ssl,
2790 sig_start, signature_len, sig_max_len );
2791 if( ret != MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
2792 {
2793 ssl->handshake->async_in_progress = 0;
2794 mbedtls_ssl_set_async_operation_data( ssl, NULL );
2795 }
2796 MBEDTLS_SSL_DEBUG_RET( 2, "ssl_resume_server_key_exchange", ret );
2797 return( ret );
2798 }
2799 #endif /* defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) &&
2800 defined(MBEDTLS_SSL_ASYNC_PRIVATE) */
2801
2802 /* Prepare the ServerKeyExchange message, up to and including
2803 * calculating the signature if any, but excluding formatting the
2804 * signature and sending the message. */
2805 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_prepare_server_key_exchange(mbedtls_ssl_context * ssl,size_t * signature_len)2806 static int ssl_prepare_server_key_exchange( mbedtls_ssl_context *ssl,
2807 size_t *signature_len )
2808 {
2809 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
2810 ssl->handshake->ciphersuite_info;
2811
2812 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PFS_ENABLED)
2813 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED)
2814 unsigned char *dig_signed = NULL;
2815 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */
2816 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PFS_ENABLED */
2817
2818 (void) ciphersuite_info; /* unused in some configurations */
2819 #if !defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED)
2820 (void) signature_len;
2821 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */
2822
2823 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED)
2824 #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
2825 size_t out_buf_len = ssl->out_buf_len - ( ssl->out_msg - ssl->out_buf );
2826 #else
2827 size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN - ( ssl->out_msg - ssl->out_buf );
2828 #endif
2829 #endif
2830
2831 ssl->out_msglen = 4; /* header (type:1, length:3) to be written later */
2832
2833 /*
2834 *
2835 * Part 1: Provide key exchange parameters for chosen ciphersuite.
2836 *
2837 */
2838
2839 /*
2840 * - ECJPAKE key exchanges
2841 */
2842 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
2843 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
2844 {
2845 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2846 #if defined(MBEDTLS_USE_PSA_CRYPTO)
2847 unsigned char *out_p = ssl->out_msg + ssl->out_msglen;
2848 unsigned char *end_p = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN -
2849 ssl->out_msglen;
2850 size_t output_offset = 0;
2851 size_t output_len = 0;
2852 const mbedtls_ecp_curve_info *curve_info;
2853
2854 /*
2855 * The first 3 bytes are:
2856 * [0] MBEDTLS_ECP_TLS_NAMED_CURVE
2857 * [1, 2] elliptic curve's TLS ID
2858 *
2859 * However since we only support secp256r1 for now, we hardcode its
2860 * TLS ID here
2861 */
2862 if( ( curve_info = mbedtls_ecp_curve_info_from_grp_id(
2863 MBEDTLS_ECP_DP_SECP256R1 ) ) == NULL )
2864 {
2865 return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
2866 }
2867 *out_p = MBEDTLS_ECP_TLS_NAMED_CURVE;
2868 MBEDTLS_PUT_UINT16_BE( curve_info->tls_id, out_p, 1 );
2869 output_offset += 3;
2870
2871 ret = mbedtls_psa_ecjpake_write_round( &ssl->handshake->psa_pake_ctx,
2872 out_p + output_offset,
2873 end_p - out_p - output_offset, &output_len,
2874 MBEDTLS_ECJPAKE_ROUND_TWO );
2875 if( ret != 0 )
2876 {
2877 psa_destroy_key( ssl->handshake->psa_pake_password );
2878 psa_pake_abort( &ssl->handshake->psa_pake_ctx );
2879 MBEDTLS_SSL_DEBUG_RET( 1 , "psa_pake_output", ret );
2880 return( ret );
2881 }
2882
2883 output_offset += output_len;
2884 ssl->out_msglen += output_offset;
2885 #else
2886 size_t len = 0;
2887
2888 ret = mbedtls_ecjpake_write_round_two(
2889 &ssl->handshake->ecjpake_ctx,
2890 ssl->out_msg + ssl->out_msglen,
2891 MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen, &len,
2892 ssl->conf->f_rng, ssl->conf->p_rng );
2893 if( ret != 0 )
2894 {
2895 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_write_round_two", ret );
2896 return( ret );
2897 }
2898
2899 ssl->out_msglen += len;
2900 #endif /* MBEDTLS_USE_PSA_CRYPTO */
2901 }
2902 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
2903
2904 /*
2905 * For (EC)DHE key exchanges with PSK, parameters are prefixed by support
2906 * identity hint (RFC 4279, Sec. 3). Until someone needs this feature,
2907 * we use empty support identity hints here.
2908 **/
2909 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) || \
2910 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
2911 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
2912 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
2913 {
2914 ssl->out_msg[ssl->out_msglen++] = 0x00;
2915 ssl->out_msg[ssl->out_msglen++] = 0x00;
2916 }
2917 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED ||
2918 MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
2919
2920 /*
2921 * - DHE key exchanges
2922 */
2923 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_DHE_ENABLED)
2924 if( mbedtls_ssl_ciphersuite_uses_dhe( ciphersuite_info ) )
2925 {
2926 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2927 size_t len = 0;
2928
2929 if( ssl->conf->dhm_P.p == NULL || ssl->conf->dhm_G.p == NULL )
2930 {
2931 MBEDTLS_SSL_DEBUG_MSG( 1, ( "no DH parameters set" ) );
2932 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
2933 }
2934
2935 /*
2936 * Ephemeral DH parameters:
2937 *
2938 * struct {
2939 * opaque dh_p<1..2^16-1>;
2940 * opaque dh_g<1..2^16-1>;
2941 * opaque dh_Ys<1..2^16-1>;
2942 * } ServerDHParams;
2943 */
2944 if( ( ret = mbedtls_dhm_set_group( &ssl->handshake->dhm_ctx,
2945 &ssl->conf->dhm_P,
2946 &ssl->conf->dhm_G ) ) != 0 )
2947 {
2948 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_set_group", ret );
2949 return( ret );
2950 }
2951
2952 if( ( ret = mbedtls_dhm_make_params(
2953 &ssl->handshake->dhm_ctx,
2954 (int) mbedtls_dhm_get_len( &ssl->handshake->dhm_ctx ),
2955 ssl->out_msg + ssl->out_msglen, &len,
2956 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
2957 {
2958 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_params", ret );
2959 return( ret );
2960 }
2961
2962 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED)
2963 dig_signed = ssl->out_msg + ssl->out_msglen;
2964 #endif
2965
2966 ssl->out_msglen += len;
2967
2968 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X );
2969 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P );
2970 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G );
2971 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX );
2972 }
2973 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_DHE_ENABLED */
2974
2975 /*
2976 * - ECDHE key exchanges
2977 */
2978 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDHE_ENABLED)
2979 if( mbedtls_ssl_ciphersuite_uses_ecdhe( ciphersuite_info ) )
2980 {
2981 /*
2982 * Ephemeral ECDH parameters:
2983 *
2984 * struct {
2985 * ECParameters curve_params;
2986 * ECPoint public;
2987 * } ServerECDHParams;
2988 */
2989 const mbedtls_ecp_curve_info **curve = NULL;
2990 const uint16_t *group_list = mbedtls_ssl_get_groups( ssl );
2991 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
2992 size_t len = 0;
2993
2994 /* Match our preference list against the offered curves */
2995 if( group_list == NULL )
2996 return( MBEDTLS_ERR_SSL_BAD_CONFIG );
2997 for( ; *group_list != 0; group_list++ )
2998 for( curve = ssl->handshake->curves; *curve != NULL; curve++ )
2999 if( (*curve)->tls_id == *group_list )
3000 goto curve_matching_done;
3001
3002 curve_matching_done:
3003 if( curve == NULL || *curve == NULL )
3004 {
3005 MBEDTLS_SSL_DEBUG_MSG( 1, ( "no matching curve for ECDHE" ) );
3006 return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
3007 }
3008
3009 MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDHE curve: %s", (*curve)->name ) );
3010
3011 #if defined(MBEDTLS_USE_PSA_CRYPTO)
3012 psa_status_t status = PSA_ERROR_GENERIC_ERROR;
3013 psa_key_attributes_t key_attributes;
3014 mbedtls_ssl_handshake_params *handshake = ssl->handshake;
3015 size_t ecdh_bits = 0;
3016 uint8_t *p = ssl->out_msg + ssl->out_msglen;
3017 const size_t header_size = 4; // curve_type(1), namedcurve(2),
3018 // data length(1)
3019 const size_t data_length_size = 1;
3020
3021 MBEDTLS_SSL_DEBUG_MSG( 1, ( "Perform PSA-based ECDH computation." ) );
3022
3023 /* Convert EC group to PSA key type. */
3024 handshake->ecdh_psa_type = mbedtls_psa_parse_tls_ecc_group(
3025 (*curve)->tls_id, &ecdh_bits );
3026
3027 if( handshake->ecdh_psa_type == 0 )
3028 {
3029 MBEDTLS_SSL_DEBUG_MSG( 1, ( "Invalid ecc group parse." ) );
3030 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
3031 }
3032 handshake->ecdh_bits = ecdh_bits;
3033
3034 key_attributes = psa_key_attributes_init();
3035 psa_set_key_usage_flags( &key_attributes, PSA_KEY_USAGE_DERIVE );
3036 psa_set_key_algorithm( &key_attributes, PSA_ALG_ECDH );
3037 psa_set_key_type( &key_attributes, handshake->ecdh_psa_type );
3038 psa_set_key_bits( &key_attributes, handshake->ecdh_bits );
3039
3040 /*
3041 * ECParameters curve_params
3042 *
3043 * First byte is curve_type, always named_curve
3044 */
3045 *p++ = MBEDTLS_ECP_TLS_NAMED_CURVE;
3046
3047 /*
3048 * Next two bytes are the namedcurve value
3049 */
3050 MBEDTLS_PUT_UINT16_BE( (*curve)->tls_id, p, 0 );
3051 p += 2;
3052
3053 /* Generate ECDH private key. */
3054 status = psa_generate_key( &key_attributes,
3055 &handshake->ecdh_psa_privkey );
3056 if( status != PSA_SUCCESS )
3057 {
3058 ret = psa_ssl_status_to_mbedtls( status );
3059 MBEDTLS_SSL_DEBUG_RET( 1, "psa_generate_key", ret );
3060 return( ret );
3061 }
3062
3063 /*
3064 * ECPoint public
3065 *
3066 * First byte is data length.
3067 * It will be filled later. p holds now the data length location.
3068 */
3069
3070 /* Export the public part of the ECDH private key from PSA.
3071 * Make one byte space for the length.
3072 */
3073 unsigned char *own_pubkey = p + data_length_size;
3074
3075 size_t own_pubkey_max_len = (size_t)( MBEDTLS_SSL_OUT_CONTENT_LEN
3076 - ( own_pubkey - ssl->out_msg ) );
3077
3078 status = psa_export_public_key( handshake->ecdh_psa_privkey,
3079 own_pubkey, own_pubkey_max_len,
3080 &len );
3081 if( status != PSA_SUCCESS )
3082 {
3083 ret = psa_ssl_status_to_mbedtls( status );
3084 MBEDTLS_SSL_DEBUG_RET( 1, "psa_export_public_key", ret );
3085 (void) psa_destroy_key( handshake->ecdh_psa_privkey );
3086 handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
3087 return( ret );
3088 }
3089
3090 /* Store the length of the exported public key. */
3091 *p = (uint8_t) len;
3092
3093 /* Determine full message length. */
3094 len += header_size;
3095 #else
3096 if( ( ret = mbedtls_ecdh_setup( &ssl->handshake->ecdh_ctx,
3097 (*curve)->grp_id ) ) != 0 )
3098 {
3099 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecp_group_load", ret );
3100 return( ret );
3101 }
3102
3103 if( ( ret = mbedtls_ecdh_make_params(
3104 &ssl->handshake->ecdh_ctx, &len,
3105 ssl->out_msg + ssl->out_msglen,
3106 MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen,
3107 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
3108 {
3109 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_params", ret );
3110 return( ret );
3111 }
3112
3113 MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
3114 MBEDTLS_DEBUG_ECDH_Q );
3115 #endif /* MBEDTLS_USE_PSA_CRYPTO */
3116
3117 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED)
3118 dig_signed = ssl->out_msg + ssl->out_msglen;
3119 #endif
3120
3121 ssl->out_msglen += len;
3122 }
3123 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_ECDHE_ENABLED */
3124
3125 /*
3126 *
3127 * Part 2: For key exchanges involving the server signing the
3128 * exchange parameters, compute and add the signature here.
3129 *
3130 */
3131 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED)
3132 if( mbedtls_ssl_ciphersuite_uses_server_signature( ciphersuite_info ) )
3133 {
3134 if( dig_signed == NULL )
3135 {
3136 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3137 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3138 }
3139
3140 size_t dig_signed_len = ssl->out_msg + ssl->out_msglen - dig_signed;
3141 size_t hashlen = 0;
3142 unsigned char hash[MBEDTLS_HASH_MAX_SIZE];
3143
3144 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
3145
3146 /*
3147 * 2.1: Choose hash algorithm:
3148 * For TLS 1.2, obey signature-hash-algorithm extension
3149 * to choose appropriate hash.
3150 */
3151
3152 mbedtls_pk_type_t sig_alg =
3153 mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
3154
3155 unsigned int sig_hash =
3156 mbedtls_ssl_tls12_get_preferred_hash_for_sig_alg(
3157 ssl, mbedtls_ssl_sig_from_pk_alg( sig_alg ) );
3158
3159 mbedtls_md_type_t md_alg = mbedtls_ssl_md_alg_from_hash( sig_hash );
3160
3161 /* For TLS 1.2, obey signature-hash-algorithm extension
3162 * (RFC 5246, Sec. 7.4.1.4.1). */
3163 if( sig_alg == MBEDTLS_PK_NONE || md_alg == MBEDTLS_MD_NONE )
3164 {
3165 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3166 /* (... because we choose a cipher suite
3167 * only if there is a matching hash.) */
3168 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3169 }
3170
3171 MBEDTLS_SSL_DEBUG_MSG( 3, ( "pick hash algorithm %u for signing", (unsigned) md_alg ) );
3172
3173 /*
3174 * 2.2: Compute the hash to be signed
3175 */
3176 if( md_alg != MBEDTLS_MD_NONE )
3177 {
3178 ret = mbedtls_ssl_get_key_exchange_md_tls1_2( ssl, hash, &hashlen,
3179 dig_signed,
3180 dig_signed_len,
3181 md_alg );
3182 if( ret != 0 )
3183 return( ret );
3184 }
3185 else
3186 {
3187 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3188 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3189 }
3190
3191 MBEDTLS_SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen );
3192
3193 /*
3194 * 2.3: Compute and add the signature
3195 */
3196 /*
3197 * We need to specify signature and hash algorithm explicitly through
3198 * a prefix to the signature.
3199 *
3200 * struct {
3201 * HashAlgorithm hash;
3202 * SignatureAlgorithm signature;
3203 * } SignatureAndHashAlgorithm;
3204 *
3205 * struct {
3206 * SignatureAndHashAlgorithm algorithm;
3207 * opaque signature<0..2^16-1>;
3208 * } DigitallySigned;
3209 *
3210 */
3211
3212 ssl->out_msg[ssl->out_msglen++] = mbedtls_ssl_hash_from_md_alg( md_alg );
3213 ssl->out_msg[ssl->out_msglen++] = mbedtls_ssl_sig_from_pk_alg( sig_alg );
3214
3215 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
3216 if( ssl->conf->f_async_sign_start != NULL )
3217 {
3218 ret = ssl->conf->f_async_sign_start( ssl,
3219 mbedtls_ssl_own_cert( ssl ),
3220 md_alg, hash, hashlen );
3221 switch( ret )
3222 {
3223 case MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH:
3224 /* act as if f_async_sign was null */
3225 break;
3226 case 0:
3227 ssl->handshake->async_in_progress = 1;
3228 return( ssl_resume_server_key_exchange( ssl, signature_len ) );
3229 case MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS:
3230 ssl->handshake->async_in_progress = 1;
3231 return( MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS );
3232 default:
3233 MBEDTLS_SSL_DEBUG_RET( 1, "f_async_sign_start", ret );
3234 return( ret );
3235 }
3236 }
3237 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
3238
3239 if( mbedtls_ssl_own_key( ssl ) == NULL )
3240 {
3241 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key" ) );
3242 return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
3243 }
3244
3245 /* Append the signature to ssl->out_msg, leaving 2 bytes for the
3246 * signature length which will be added in ssl_write_server_key_exchange
3247 * after the call to ssl_prepare_server_key_exchange.
3248 * ssl_write_server_key_exchange also takes care of incrementing
3249 * ssl->out_msglen. */
3250 if( ( ret = mbedtls_pk_sign( mbedtls_ssl_own_key( ssl ),
3251 md_alg, hash, hashlen,
3252 ssl->out_msg + ssl->out_msglen + 2,
3253 out_buf_len - ssl->out_msglen - 2,
3254 signature_len,
3255 ssl->conf->f_rng,
3256 ssl->conf->p_rng ) ) != 0 )
3257 {
3258 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_sign", ret );
3259 return( ret );
3260 }
3261 }
3262 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */
3263
3264 return( 0 );
3265 }
3266
3267 /* Prepare the ServerKeyExchange message and send it. For ciphersuites
3268 * that do not include a ServerKeyExchange message, do nothing. Either
3269 * way, if successful, move on to the next step in the SSL state
3270 * machine. */
3271 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_write_server_key_exchange(mbedtls_ssl_context * ssl)3272 static int ssl_write_server_key_exchange( mbedtls_ssl_context *ssl )
3273 {
3274 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
3275 size_t signature_len = 0;
3276 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_NON_PFS_ENABLED)
3277 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
3278 ssl->handshake->ciphersuite_info;
3279 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_NON_PFS_ENABLED */
3280
3281 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server key exchange" ) );
3282
3283 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_NON_PFS_ENABLED)
3284 /* Extract static ECDH parameters and abort if ServerKeyExchange
3285 * is not needed. */
3286 if( mbedtls_ssl_ciphersuite_no_pfs( ciphersuite_info ) )
3287 {
3288 /* For suites involving ECDH, extract DH parameters
3289 * from certificate at this point. */
3290 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_ENABLED)
3291 if( mbedtls_ssl_ciphersuite_uses_ecdh( ciphersuite_info ) )
3292 {
3293 ret = ssl_get_ecdh_params_from_cert( ssl );
3294 if( ret != 0 )
3295 {
3296 MBEDTLS_SSL_DEBUG_RET( 1, "ssl_get_ecdh_params_from_cert", ret );
3297 return( ret );
3298 }
3299 }
3300 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_ECDH_ENABLED */
3301
3302 /* Key exchanges not involving ephemeral keys don't use
3303 * ServerKeyExchange, so end here. */
3304 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write server key exchange" ) );
3305 ssl->state++;
3306 return( 0 );
3307 }
3308 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_NON_PFS_ENABLED */
3309
3310 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) && \
3311 defined(MBEDTLS_SSL_ASYNC_PRIVATE)
3312 /* If we have already prepared the message and there is an ongoing
3313 * signature operation, resume signing. */
3314 if( ssl->handshake->async_in_progress != 0 )
3315 {
3316 MBEDTLS_SSL_DEBUG_MSG( 2, ( "resuming signature operation" ) );
3317 ret = ssl_resume_server_key_exchange( ssl, &signature_len );
3318 }
3319 else
3320 #endif /* defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) &&
3321 defined(MBEDTLS_SSL_ASYNC_PRIVATE) */
3322 {
3323 /* ServerKeyExchange is needed. Prepare the message. */
3324 ret = ssl_prepare_server_key_exchange( ssl, &signature_len );
3325 }
3326
3327 if( ret != 0 )
3328 {
3329 /* If we're starting to write a new message, set ssl->out_msglen
3330 * to 0. But if we're resuming after an asynchronous message,
3331 * out_msglen is the amount of data written so far and mst be
3332 * preserved. */
3333 if( ret == MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
3334 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server key exchange (pending)" ) );
3335 else
3336 ssl->out_msglen = 0;
3337 return( ret );
3338 }
3339
3340 /* If there is a signature, write its length.
3341 * ssl_prepare_server_key_exchange already wrote the signature
3342 * itself at its proper place in the output buffer. */
3343 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED)
3344 if( signature_len != 0 )
3345 {
3346 ssl->out_msg[ssl->out_msglen++] = MBEDTLS_BYTE_1( signature_len );
3347 ssl->out_msg[ssl->out_msglen++] = MBEDTLS_BYTE_0( signature_len );
3348
3349 MBEDTLS_SSL_DEBUG_BUF( 3, "my signature",
3350 ssl->out_msg + ssl->out_msglen,
3351 signature_len );
3352
3353 /* Skip over the already-written signature */
3354 ssl->out_msglen += signature_len;
3355 }
3356 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */
3357
3358 /* Add header and send. */
3359 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
3360 ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE;
3361
3362 ssl->state++;
3363
3364 if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
3365 {
3366 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
3367 return( ret );
3368 }
3369
3370 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server key exchange" ) );
3371 return( 0 );
3372 }
3373
3374 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_write_server_hello_done(mbedtls_ssl_context * ssl)3375 static int ssl_write_server_hello_done( mbedtls_ssl_context *ssl )
3376 {
3377 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
3378
3379 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server hello done" ) );
3380
3381 ssl->out_msglen = 4;
3382 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
3383 ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_HELLO_DONE;
3384
3385 ssl->state++;
3386
3387 #if defined(MBEDTLS_SSL_PROTO_DTLS)
3388 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
3389 mbedtls_ssl_send_flight_completed( ssl );
3390 #endif
3391
3392 if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
3393 {
3394 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
3395 return( ret );
3396 }
3397
3398 #if defined(MBEDTLS_SSL_PROTO_DTLS)
3399 if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
3400 ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
3401 {
3402 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flight_transmit", ret );
3403 return( ret );
3404 }
3405 #endif /* MBEDTLS_SSL_PROTO_DTLS */
3406
3407 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello done" ) );
3408
3409 return( 0 );
3410 }
3411
3412 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
3413 defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
3414 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_client_dh_public(mbedtls_ssl_context * ssl,unsigned char ** p,const unsigned char * end)3415 static int ssl_parse_client_dh_public( mbedtls_ssl_context *ssl, unsigned char **p,
3416 const unsigned char *end )
3417 {
3418 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
3419 size_t n;
3420
3421 /*
3422 * Receive G^Y mod P, premaster = (G^Y)^X mod P
3423 */
3424 if( *p + 2 > end )
3425 {
3426 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3427 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3428 }
3429
3430 n = ( (*p)[0] << 8 ) | (*p)[1];
3431 *p += 2;
3432
3433 if( *p + n > end )
3434 {
3435 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3436 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3437 }
3438
3439 if( ( ret = mbedtls_dhm_read_public( &ssl->handshake->dhm_ctx, *p, n ) ) != 0 )
3440 {
3441 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_read_public", ret );
3442 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3443 }
3444
3445 *p += n;
3446
3447 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
3448
3449 return( ret );
3450 }
3451 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
3452 MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
3453
3454 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
3455 defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
3456
3457 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
3458 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_resume_decrypt_pms(mbedtls_ssl_context * ssl,unsigned char * peer_pms,size_t * peer_pmslen,size_t peer_pmssize)3459 static int ssl_resume_decrypt_pms( mbedtls_ssl_context *ssl,
3460 unsigned char *peer_pms,
3461 size_t *peer_pmslen,
3462 size_t peer_pmssize )
3463 {
3464 int ret = ssl->conf->f_async_resume( ssl,
3465 peer_pms, peer_pmslen, peer_pmssize );
3466 if( ret != MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
3467 {
3468 ssl->handshake->async_in_progress = 0;
3469 mbedtls_ssl_set_async_operation_data( ssl, NULL );
3470 }
3471 MBEDTLS_SSL_DEBUG_RET( 2, "ssl_decrypt_encrypted_pms", ret );
3472 return( ret );
3473 }
3474 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
3475
3476 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_decrypt_encrypted_pms(mbedtls_ssl_context * ssl,const unsigned char * p,const unsigned char * end,unsigned char * peer_pms,size_t * peer_pmslen,size_t peer_pmssize)3477 static int ssl_decrypt_encrypted_pms( mbedtls_ssl_context *ssl,
3478 const unsigned char *p,
3479 const unsigned char *end,
3480 unsigned char *peer_pms,
3481 size_t *peer_pmslen,
3482 size_t peer_pmssize )
3483 {
3484 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
3485
3486 mbedtls_x509_crt *own_cert = mbedtls_ssl_own_cert( ssl );
3487 if( own_cert == NULL ) {
3488 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no local certificate" ) );
3489 return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE );
3490 }
3491 mbedtls_pk_context *public_key = &own_cert->pk;
3492 mbedtls_pk_context *private_key = mbedtls_ssl_own_key( ssl );
3493 size_t len = mbedtls_pk_get_len( public_key );
3494
3495 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
3496 /* If we have already started decoding the message and there is an ongoing
3497 * decryption operation, resume signing. */
3498 if( ssl->handshake->async_in_progress != 0 )
3499 {
3500 MBEDTLS_SSL_DEBUG_MSG( 2, ( "resuming decryption operation" ) );
3501 return( ssl_resume_decrypt_pms( ssl,
3502 peer_pms, peer_pmslen, peer_pmssize ) );
3503 }
3504 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
3505
3506 /*
3507 * Prepare to decrypt the premaster using own private RSA key
3508 */
3509 if ( p + 2 > end ) {
3510 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3511 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3512 }
3513 if( *p++ != MBEDTLS_BYTE_1( len ) ||
3514 *p++ != MBEDTLS_BYTE_0( len ) )
3515 {
3516 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3517 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3518 }
3519
3520 if( p + len != end )
3521 {
3522 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3523 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3524 }
3525
3526 /*
3527 * Decrypt the premaster secret
3528 */
3529 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
3530 if( ssl->conf->f_async_decrypt_start != NULL )
3531 {
3532 ret = ssl->conf->f_async_decrypt_start( ssl,
3533 mbedtls_ssl_own_cert( ssl ),
3534 p, len );
3535 switch( ret )
3536 {
3537 case MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH:
3538 /* act as if f_async_decrypt_start was null */
3539 break;
3540 case 0:
3541 ssl->handshake->async_in_progress = 1;
3542 return( ssl_resume_decrypt_pms( ssl,
3543 peer_pms,
3544 peer_pmslen,
3545 peer_pmssize ) );
3546 case MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS:
3547 ssl->handshake->async_in_progress = 1;
3548 return( MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS );
3549 default:
3550 MBEDTLS_SSL_DEBUG_RET( 1, "f_async_decrypt_start", ret );
3551 return( ret );
3552 }
3553 }
3554 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
3555
3556 if( ! mbedtls_pk_can_do( private_key, MBEDTLS_PK_RSA ) )
3557 {
3558 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no RSA private key" ) );
3559 return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
3560 }
3561
3562 ret = mbedtls_pk_decrypt( private_key, p, len,
3563 peer_pms, peer_pmslen, peer_pmssize,
3564 ssl->conf->f_rng, ssl->conf->p_rng );
3565 return( ret );
3566 }
3567
3568 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_encrypted_pms(mbedtls_ssl_context * ssl,const unsigned char * p,const unsigned char * end,size_t pms_offset)3569 static int ssl_parse_encrypted_pms( mbedtls_ssl_context *ssl,
3570 const unsigned char *p,
3571 const unsigned char *end,
3572 size_t pms_offset )
3573 {
3574 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
3575 unsigned char *pms = ssl->handshake->premaster + pms_offset;
3576 unsigned char ver[2];
3577 unsigned char fake_pms[48], peer_pms[48];
3578 unsigned char mask;
3579 size_t i, peer_pmslen;
3580 unsigned int diff;
3581
3582 /* In case of a failure in decryption, the decryption may write less than
3583 * 2 bytes of output, but we always read the first two bytes. It doesn't
3584 * matter in the end because diff will be nonzero in that case due to
3585 * ret being nonzero, and we only care whether diff is 0.
3586 * But do initialize peer_pms and peer_pmslen for robustness anyway. This
3587 * also makes memory analyzers happy (don't access uninitialized memory,
3588 * even if it's an unsigned char). */
3589 peer_pms[0] = peer_pms[1] = ~0;
3590 peer_pmslen = 0;
3591
3592 ret = ssl_decrypt_encrypted_pms( ssl, p, end,
3593 peer_pms,
3594 &peer_pmslen,
3595 sizeof( peer_pms ) );
3596
3597 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
3598 if ( ret == MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS )
3599 return( ret );
3600 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
3601
3602 mbedtls_ssl_write_version( ver, ssl->conf->transport,
3603 ssl->session_negotiate->tls_version );
3604
3605 /* Avoid data-dependent branches while checking for invalid
3606 * padding, to protect against timing-based Bleichenbacher-type
3607 * attacks. */
3608 diff = (unsigned int) ret;
3609 diff |= peer_pmslen ^ 48;
3610 diff |= peer_pms[0] ^ ver[0];
3611 diff |= peer_pms[1] ^ ver[1];
3612
3613 /* mask = diff ? 0xff : 0x00 using bit operations to avoid branches */
3614 mask = mbedtls_ct_uint_mask( diff );
3615
3616 /*
3617 * Protection against Bleichenbacher's attack: invalid PKCS#1 v1.5 padding
3618 * must not cause the connection to end immediately; instead, send a
3619 * bad_record_mac later in the handshake.
3620 * To protect against timing-based variants of the attack, we must
3621 * not have any branch that depends on whether the decryption was
3622 * successful. In particular, always generate the fake premaster secret,
3623 * regardless of whether it will ultimately influence the output or not.
3624 */
3625 ret = ssl->conf->f_rng( ssl->conf->p_rng, fake_pms, sizeof( fake_pms ) );
3626 if( ret != 0 )
3627 {
3628 /* It's ok to abort on an RNG failure, since this does not reveal
3629 * anything about the RSA decryption. */
3630 return( ret );
3631 }
3632
3633 #if defined(MBEDTLS_SSL_DEBUG_ALL)
3634 if( diff != 0 )
3635 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3636 #endif
3637
3638 if( sizeof( ssl->handshake->premaster ) < pms_offset ||
3639 sizeof( ssl->handshake->premaster ) - pms_offset < 48 )
3640 {
3641 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
3642 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
3643 }
3644 ssl->handshake->pmslen = 48;
3645
3646 /* Set pms to either the true or the fake PMS, without
3647 * data-dependent branches. */
3648 for( i = 0; i < ssl->handshake->pmslen; i++ )
3649 pms[i] = ( mask & fake_pms[i] ) | ( (~mask) & peer_pms[i] );
3650
3651 return( 0 );
3652 }
3653 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED ||
3654 MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
3655
3656 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
3657 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_client_psk_identity(mbedtls_ssl_context * ssl,unsigned char ** p,const unsigned char * end)3658 static int ssl_parse_client_psk_identity( mbedtls_ssl_context *ssl, unsigned char **p,
3659 const unsigned char *end )
3660 {
3661 int ret = 0;
3662 uint16_t n;
3663
3664 if( ssl_conf_has_psk_or_cb( ssl->conf ) == 0 )
3665 {
3666 MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no pre-shared key" ) );
3667 return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
3668 }
3669
3670 /*
3671 * Receive client pre-shared key identity name
3672 */
3673 if( end - *p < 2 )
3674 {
3675 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3676 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3677 }
3678
3679 n = ( (*p)[0] << 8 ) | (*p)[1];
3680 *p += 2;
3681
3682 if( n == 0 || n > end - *p )
3683 {
3684 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3685 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3686 }
3687
3688 if( ssl->conf->f_psk != NULL )
3689 {
3690 if( ssl->conf->f_psk( ssl->conf->p_psk, ssl, *p, n ) != 0 )
3691 ret = MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY;
3692 }
3693 else
3694 {
3695 /* Identity is not a big secret since clients send it in the clear,
3696 * but treat it carefully anyway, just in case */
3697 if( n != ssl->conf->psk_identity_len ||
3698 mbedtls_ct_memcmp( ssl->conf->psk_identity, *p, n ) != 0 )
3699 {
3700 ret = MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY;
3701 }
3702 }
3703
3704 if( ret == MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY )
3705 {
3706 MBEDTLS_SSL_DEBUG_BUF( 3, "Unknown PSK identity", *p, n );
3707 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
3708 MBEDTLS_SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY );
3709 return( MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY );
3710 }
3711
3712 *p += n;
3713
3714 return( 0 );
3715 }
3716 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
3717
3718 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_client_key_exchange(mbedtls_ssl_context * ssl)3719 static int ssl_parse_client_key_exchange( mbedtls_ssl_context *ssl )
3720 {
3721 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
3722 const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
3723 unsigned char *p, *end;
3724
3725 ciphersuite_info = ssl->handshake->ciphersuite_info;
3726
3727 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client key exchange" ) );
3728
3729 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE) && \
3730 ( defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
3731 defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) )
3732 if( ( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
3733 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA ) &&
3734 ( ssl->handshake->async_in_progress != 0 ) )
3735 {
3736 /* We've already read a record and there is an asynchronous
3737 * operation in progress to decrypt it. So skip reading the
3738 * record. */
3739 MBEDTLS_SSL_DEBUG_MSG( 3, ( "will resume decryption of previously-read record" ) );
3740 }
3741 else
3742 #endif
3743 if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
3744 {
3745 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
3746 return( ret );
3747 }
3748
3749 p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
3750 end = ssl->in_msg + ssl->in_hslen;
3751
3752 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
3753 {
3754 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3755 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
3756 }
3757
3758 if( ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE )
3759 {
3760 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
3761 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
3762 }
3763
3764 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)
3765 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA )
3766 {
3767 if( ( ret = ssl_parse_client_dh_public( ssl, &p, end ) ) != 0 )
3768 {
3769 MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_dh_public" ), ret );
3770 return( ret );
3771 }
3772
3773 if( p != end )
3774 {
3775 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
3776 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3777 }
3778
3779 if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx,
3780 ssl->handshake->premaster,
3781 MBEDTLS_PREMASTER_SIZE,
3782 &ssl->handshake->pmslen,
3783 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
3784 {
3785 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret );
3786 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3787 }
3788
3789 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
3790 }
3791 else
3792 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED */
3793 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
3794 defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
3795 defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
3796 defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
3797 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
3798 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA ||
3799 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
3800 ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
3801 {
3802 #if defined(MBEDTLS_USE_PSA_CRYPTO)
3803 size_t data_len = (size_t)( *p++ );
3804 size_t buf_len = (size_t)( end - p );
3805 psa_status_t status = PSA_ERROR_GENERIC_ERROR;
3806 mbedtls_ssl_handshake_params *handshake = ssl->handshake;
3807
3808 MBEDTLS_SSL_DEBUG_MSG( 1, ( "Read the peer's public key." ) );
3809
3810 /*
3811 * We must have at least two bytes (1 for length, at least 1 for data)
3812 */
3813 if( buf_len < 2 )
3814 {
3815 MBEDTLS_SSL_DEBUG_MSG( 1, ( "Invalid buffer length" ) );
3816 return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
3817 }
3818
3819 if( data_len < 1 || data_len > buf_len )
3820 {
3821 MBEDTLS_SSL_DEBUG_MSG( 1, ( "Invalid data length" ) );
3822 return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
3823 }
3824
3825 /* Store peer's ECDH public key. */
3826 memcpy( handshake->ecdh_psa_peerkey, p, data_len );
3827 handshake->ecdh_psa_peerkey_len = data_len;
3828
3829 /* Compute ECDH shared secret. */
3830 status = psa_raw_key_agreement(
3831 PSA_ALG_ECDH, handshake->ecdh_psa_privkey,
3832 handshake->ecdh_psa_peerkey, handshake->ecdh_psa_peerkey_len,
3833 handshake->premaster, sizeof( handshake->premaster ),
3834 &handshake->pmslen );
3835 if( status != PSA_SUCCESS )
3836 {
3837 ret = psa_ssl_status_to_mbedtls( status );
3838 MBEDTLS_SSL_DEBUG_RET( 1, "psa_raw_key_agreement", ret );
3839 if( handshake->ecdh_psa_privkey_is_external == 0 )
3840 (void) psa_destroy_key( handshake->ecdh_psa_privkey );
3841 handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
3842 return( ret );
3843 }
3844
3845 if( handshake->ecdh_psa_privkey_is_external == 0 )
3846 {
3847 status = psa_destroy_key( handshake->ecdh_psa_privkey );
3848
3849 if( status != PSA_SUCCESS )
3850 {
3851 ret = psa_ssl_status_to_mbedtls( status );
3852 MBEDTLS_SSL_DEBUG_RET( 1, "psa_destroy_key", ret );
3853 return( ret );
3854 }
3855 }
3856 handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
3857 #else
3858 if( ( ret = mbedtls_ecdh_read_public( &ssl->handshake->ecdh_ctx,
3859 p, end - p) ) != 0 )
3860 {
3861 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_read_public", ret );
3862 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3863 }
3864
3865 MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
3866 MBEDTLS_DEBUG_ECDH_QP );
3867
3868 if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
3869 &ssl->handshake->pmslen,
3870 ssl->handshake->premaster,
3871 MBEDTLS_MPI_MAX_SIZE,
3872 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
3873 {
3874 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_calc_secret", ret );
3875 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3876 }
3877
3878 MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
3879 MBEDTLS_DEBUG_ECDH_Z );
3880 #endif /* MBEDTLS_USE_PSA_CRYPTO */
3881 }
3882 else
3883 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
3884 MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
3885 MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
3886 MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
3887 #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
3888 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK )
3889 {
3890 if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
3891 {
3892 MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
3893 return( ret );
3894 }
3895
3896 if( p != end )
3897 {
3898 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
3899 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3900 }
3901
3902 #if !defined(MBEDTLS_USE_PSA_CRYPTO)
3903 if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
3904 ciphersuite_info->key_exchange ) ) != 0 )
3905 {
3906 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
3907 return( ret );
3908 }
3909 #endif /* !MBEDTLS_USE_PSA_CRYPTO */
3910 }
3911 else
3912 #endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */
3913 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
3914 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
3915 {
3916 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
3917 if ( ssl->handshake->async_in_progress != 0 )
3918 {
3919 /* There is an asynchronous operation in progress to
3920 * decrypt the encrypted premaster secret, so skip
3921 * directly to resuming this operation. */
3922 MBEDTLS_SSL_DEBUG_MSG( 3, ( "PSK identity already parsed" ) );
3923 /* Update p to skip the PSK identity. ssl_parse_encrypted_pms
3924 * won't actually use it, but maintain p anyway for robustness. */
3925 p += ssl->conf->psk_identity_len + 2;
3926 }
3927 else
3928 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
3929 if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
3930 {
3931 MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
3932 return( ret );
3933 }
3934
3935 if( ( ret = ssl_parse_encrypted_pms( ssl, p, end, 2 ) ) != 0 )
3936 {
3937 MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_encrypted_pms" ), ret );
3938 return( ret );
3939 }
3940
3941 #if !defined(MBEDTLS_USE_PSA_CRYPTO)
3942 if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
3943 ciphersuite_info->key_exchange ) ) != 0 )
3944 {
3945 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
3946 return( ret );
3947 }
3948 #endif /* !MBEDTLS_USE_PSA_CRYPTO */
3949 }
3950 else
3951 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
3952 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
3953 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK )
3954 {
3955 if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
3956 {
3957 MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
3958 return( ret );
3959 }
3960 if( ( ret = ssl_parse_client_dh_public( ssl, &p, end ) ) != 0 )
3961 {
3962 MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_dh_public" ), ret );
3963 return( ret );
3964 }
3965
3966 if( p != end )
3967 {
3968 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
3969 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
3970 }
3971
3972 #if defined(MBEDTLS_USE_PSA_CRYPTO)
3973 unsigned char *pms = ssl->handshake->premaster;
3974 unsigned char *pms_end = pms + sizeof( ssl->handshake->premaster );
3975 size_t pms_len;
3976
3977 /* Write length only when we know the actual value */
3978 if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx,
3979 pms + 2, pms_end - ( pms + 2 ), &pms_len,
3980 ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
3981 {
3982 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret );
3983 return( ret );
3984 }
3985 MBEDTLS_PUT_UINT16_BE( pms_len, pms, 0 );
3986 pms += 2 + pms_len;
3987
3988 MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
3989 #else
3990 if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
3991 ciphersuite_info->key_exchange ) ) != 0 )
3992 {
3993 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
3994 return( ret );
3995 }
3996 #endif /* MBEDTLS_USE_PSA_CRYPTO */
3997 }
3998 else
3999 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
4000 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
4001 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
4002 {
4003 #if defined(MBEDTLS_USE_PSA_CRYPTO)
4004 psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
4005 psa_status_t destruction_status = PSA_ERROR_CORRUPTION_DETECTED;
4006 uint8_t ecpoint_len;
4007
4008 mbedtls_ssl_handshake_params *handshake = ssl->handshake;
4009
4010 if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
4011 {
4012 MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
4013 psa_destroy_key( handshake->ecdh_psa_privkey );
4014 handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
4015 return( ret );
4016 }
4017
4018 /* Keep a copy of the peer's public key */
4019 if( p >= end )
4020 {
4021 psa_destroy_key( handshake->ecdh_psa_privkey );
4022 handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
4023 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
4024 }
4025
4026 ecpoint_len = *(p++);
4027 if( (size_t)( end - p ) < ecpoint_len ) {
4028 psa_destroy_key( handshake->ecdh_psa_privkey );
4029 handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
4030 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
4031 }
4032
4033 if( ecpoint_len > sizeof( handshake->ecdh_psa_peerkey ) ) {
4034 psa_destroy_key( handshake->ecdh_psa_privkey );
4035 handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
4036 return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
4037 }
4038
4039 memcpy( handshake->ecdh_psa_peerkey, p, ecpoint_len );
4040 handshake->ecdh_psa_peerkey_len = ecpoint_len;
4041 p += ecpoint_len;
4042
4043 /* As RFC 5489 section 2, the premaster secret is formed as follows:
4044 * - a uint16 containing the length (in octets) of the ECDH computation
4045 * - the octet string produced by the ECDH computation
4046 * - a uint16 containing the length (in octets) of the PSK
4047 * - the PSK itself
4048 */
4049 unsigned char *psm = ssl->handshake->premaster;
4050 const unsigned char* const psm_end =
4051 psm + sizeof( ssl->handshake->premaster );
4052 /* uint16 to store length (in octets) of the ECDH computation */
4053 const size_t zlen_size = 2;
4054 size_t zlen = 0;
4055
4056 /* Compute ECDH shared secret. */
4057 status = psa_raw_key_agreement( PSA_ALG_ECDH,
4058 handshake->ecdh_psa_privkey,
4059 handshake->ecdh_psa_peerkey,
4060 handshake->ecdh_psa_peerkey_len,
4061 psm + zlen_size,
4062 psm_end - ( psm + zlen_size ),
4063 &zlen );
4064
4065 destruction_status = psa_destroy_key( handshake->ecdh_psa_privkey );
4066 handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT;
4067
4068 if( status != PSA_SUCCESS )
4069 return( psa_ssl_status_to_mbedtls( status ) );
4070 else if( destruction_status != PSA_SUCCESS )
4071 return( psa_ssl_status_to_mbedtls( destruction_status ) );
4072
4073 /* Write the ECDH computation length before the ECDH computation */
4074 MBEDTLS_PUT_UINT16_BE( zlen, psm, 0 );
4075 psm += zlen_size + zlen;
4076
4077 #else /* MBEDTLS_USE_PSA_CRYPTO */
4078 if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
4079 {
4080 MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
4081 return( ret );
4082 }
4083
4084 if( ( ret = mbedtls_ecdh_read_public( &ssl->handshake->ecdh_ctx,
4085 p, end - p ) ) != 0 )
4086 {
4087 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_read_public", ret );
4088 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
4089 }
4090
4091 MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
4092 MBEDTLS_DEBUG_ECDH_QP );
4093
4094 if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
4095 ciphersuite_info->key_exchange ) ) != 0 )
4096 {
4097 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
4098 return( ret );
4099 }
4100 #endif /* MBEDTLS_USE_PSA_CRYPTO */
4101 }
4102 else
4103 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
4104 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
4105 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA )
4106 {
4107 if( ( ret = ssl_parse_encrypted_pms( ssl, p, end, 0 ) ) != 0 )
4108 {
4109 MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_parse_encrypted_pms_secret" ), ret );
4110 return( ret );
4111 }
4112 }
4113 else
4114 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
4115 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
4116 if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
4117 {
4118 #if defined(MBEDTLS_USE_PSA_CRYPTO)
4119 if( ( ret = mbedtls_psa_ecjpake_read_round(
4120 &ssl->handshake->psa_pake_ctx, p, end - p,
4121 MBEDTLS_ECJPAKE_ROUND_TWO ) ) != 0 )
4122 {
4123 psa_destroy_key( ssl->handshake->psa_pake_password );
4124 psa_pake_abort( &ssl->handshake->psa_pake_ctx );
4125
4126 MBEDTLS_SSL_DEBUG_RET( 1, "psa_pake_input round two", ret );
4127 return( ret );
4128 }
4129 #else
4130 ret = mbedtls_ecjpake_read_round_two( &ssl->handshake->ecjpake_ctx,
4131 p, end - p );
4132 if( ret != 0 )
4133 {
4134 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_two", ret );
4135 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
4136 }
4137
4138 ret = mbedtls_ecjpake_derive_secret( &ssl->handshake->ecjpake_ctx,
4139 ssl->handshake->premaster, 32, &ssl->handshake->pmslen,
4140 ssl->conf->f_rng, ssl->conf->p_rng );
4141 if( ret != 0 )
4142 {
4143 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_derive_secret", ret );
4144 return( ret );
4145 }
4146 #endif /* MBEDTLS_USE_PSA_CRYPTO */
4147 }
4148 else
4149 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
4150 {
4151 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
4152 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
4153 }
4154
4155 if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
4156 {
4157 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
4158 return( ret );
4159 }
4160
4161 ssl->state++;
4162
4163 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client key exchange" ) );
4164
4165 return( 0 );
4166 }
4167
4168 #if !defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED)
4169 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_certificate_verify(mbedtls_ssl_context * ssl)4170 static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
4171 {
4172 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
4173 ssl->handshake->ciphersuite_info;
4174
4175 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
4176
4177 if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
4178 {
4179 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
4180 ssl->state++;
4181 return( 0 );
4182 }
4183
4184 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
4185 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
4186 }
4187 #else /* !MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */
4188 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_parse_certificate_verify(mbedtls_ssl_context * ssl)4189 static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
4190 {
4191 int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
4192 size_t i, sig_len;
4193 unsigned char hash[48];
4194 unsigned char *hash_start = hash;
4195 size_t hashlen;
4196 mbedtls_pk_type_t pk_alg;
4197 mbedtls_md_type_t md_alg;
4198 const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
4199 ssl->handshake->ciphersuite_info;
4200 mbedtls_pk_context * peer_pk;
4201
4202 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
4203
4204 if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
4205 {
4206 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
4207 ssl->state++;
4208 return( 0 );
4209 }
4210
4211 #if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
4212 if( ssl->session_negotiate->peer_cert == NULL )
4213 {
4214 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
4215 ssl->state++;
4216 return( 0 );
4217 }
4218 #else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
4219 if( ssl->session_negotiate->peer_cert_digest == NULL )
4220 {
4221 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
4222 ssl->state++;
4223 return( 0 );
4224 }
4225 #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
4226
4227 /* Read the message without adding it to the checksum */
4228 ret = mbedtls_ssl_read_record( ssl, 0 /* no checksum update */ );
4229 if( 0 != ret )
4230 {
4231 MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_read_record" ), ret );
4232 return( ret );
4233 }
4234
4235 ssl->state++;
4236
4237 /* Process the message contents */
4238 if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ||
4239 ssl->in_msg[0] != MBEDTLS_SSL_HS_CERTIFICATE_VERIFY )
4240 {
4241 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
4242 return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
4243 }
4244
4245 i = mbedtls_ssl_hs_hdr_len( ssl );
4246
4247 #if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
4248 peer_pk = &ssl->handshake->peer_pubkey;
4249 #else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
4250 if( ssl->session_negotiate->peer_cert == NULL )
4251 {
4252 /* Should never happen */
4253 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
4254 }
4255 peer_pk = &ssl->session_negotiate->peer_cert->pk;
4256 #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
4257
4258 /*
4259 * struct {
4260 * SignatureAndHashAlgorithm algorithm; -- TLS 1.2 only
4261 * opaque signature<0..2^16-1>;
4262 * } DigitallySigned;
4263 */
4264 if( i + 2 > ssl->in_hslen )
4265 {
4266 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
4267 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
4268 }
4269
4270 /*
4271 * Hash
4272 */
4273 md_alg = mbedtls_ssl_md_alg_from_hash( ssl->in_msg[i] );
4274
4275 if( md_alg == MBEDTLS_MD_NONE || mbedtls_ssl_set_calc_verify_md( ssl, ssl->in_msg[i] ) )
4276 {
4277 MBEDTLS_SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg"
4278 " for verify message" ) );
4279 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
4280 }
4281
4282 #if !defined(MBEDTLS_MD_SHA1)
4283 if( MBEDTLS_MD_SHA1 == md_alg )
4284 hash_start += 16;
4285 #endif
4286
4287 /* Info from md_alg will be used instead */
4288 hashlen = 0;
4289
4290 i++;
4291
4292 /*
4293 * Signature
4294 */
4295 if( ( pk_alg = mbedtls_ssl_pk_alg_from_sig( ssl->in_msg[i] ) )
4296 == MBEDTLS_PK_NONE )
4297 {
4298 MBEDTLS_SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg"
4299 " for verify message" ) );
4300 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
4301 }
4302
4303 /*
4304 * Check the certificate's key type matches the signature alg
4305 */
4306 if( !mbedtls_pk_can_do( peer_pk, pk_alg ) )
4307 {
4308 MBEDTLS_SSL_DEBUG_MSG( 1, ( "sig_alg doesn't match cert key" ) );
4309 return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
4310 }
4311
4312 i++;
4313
4314 if( i + 2 > ssl->in_hslen )
4315 {
4316 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
4317 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
4318 }
4319
4320 sig_len = ( ssl->in_msg[i] << 8 ) | ssl->in_msg[i+1];
4321 i += 2;
4322
4323 if( i + sig_len != ssl->in_hslen )
4324 {
4325 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
4326 return( MBEDTLS_ERR_SSL_DECODE_ERROR );
4327 }
4328
4329 /* Calculate hash and verify signature */
4330 {
4331 size_t dummy_hlen;
4332 ssl->handshake->calc_verify( ssl, hash, &dummy_hlen );
4333 }
4334
4335 if( ( ret = mbedtls_pk_verify( peer_pk,
4336 md_alg, hash_start, hashlen,
4337 ssl->in_msg + i, sig_len ) ) != 0 )
4338 {
4339 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_verify", ret );
4340 return( ret );
4341 }
4342
4343 mbedtls_ssl_update_handshake_status( ssl );
4344
4345 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate verify" ) );
4346
4347 return( ret );
4348 }
4349 #endif /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */
4350
4351 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
4352 MBEDTLS_CHECK_RETURN_CRITICAL
ssl_write_new_session_ticket(mbedtls_ssl_context * ssl)4353 static int ssl_write_new_session_ticket( mbedtls_ssl_context *ssl )
4354 {
4355 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
4356 size_t tlen;
4357 uint32_t lifetime;
4358
4359 MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write new session ticket" ) );
4360
4361 ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
4362 ssl->out_msg[0] = MBEDTLS_SSL_HS_NEW_SESSION_TICKET;
4363
4364 /*
4365 * struct {
4366 * uint32 ticket_lifetime_hint;
4367 * opaque ticket<0..2^16-1>;
4368 * } NewSessionTicket;
4369 *
4370 * 4 . 7 ticket_lifetime_hint (0 = unspecified)
4371 * 8 . 9 ticket_len (n)
4372 * 10 . 9+n ticket content
4373 */
4374
4375 if( ( ret = ssl->conf->f_ticket_write( ssl->conf->p_ticket,
4376 ssl->session_negotiate,
4377 ssl->out_msg + 10,
4378 ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN,
4379 &tlen, &lifetime ) ) != 0 )
4380 {
4381 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_write", ret );
4382 tlen = 0;
4383 }
4384
4385 MBEDTLS_PUT_UINT32_BE( lifetime, ssl->out_msg, 4 );
4386 MBEDTLS_PUT_UINT16_BE( tlen, ssl->out_msg, 8 );
4387 ssl->out_msglen = 10 + tlen;
4388
4389 /*
4390 * Morally equivalent to updating ssl->state, but NewSessionTicket and
4391 * ChangeCipherSpec share the same state.
4392 */
4393 ssl->handshake->new_session_ticket = 0;
4394
4395 if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
4396 {
4397 MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
4398 return( ret );
4399 }
4400
4401 MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write new session ticket" ) );
4402
4403 return( 0 );
4404 }
4405 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
4406
4407 /*
4408 * SSL handshake -- server side -- single step
4409 */
mbedtls_ssl_handshake_server_step(mbedtls_ssl_context * ssl)4410 int mbedtls_ssl_handshake_server_step( mbedtls_ssl_context *ssl )
4411 {
4412 int ret = 0;
4413
4414 MBEDTLS_SSL_DEBUG_MSG( 2, ( "server state: %d", ssl->state ) );
4415
4416 switch( ssl->state )
4417 {
4418 case MBEDTLS_SSL_HELLO_REQUEST:
4419 ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
4420 break;
4421
4422 /*
4423 * <== ClientHello
4424 */
4425 case MBEDTLS_SSL_CLIENT_HELLO:
4426 ret = ssl_parse_client_hello( ssl );
4427 break;
4428
4429 #if defined(MBEDTLS_SSL_PROTO_DTLS)
4430 case MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT:
4431 return( MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED );
4432 #endif
4433
4434 /*
4435 * ==> ServerHello
4436 * Certificate
4437 * ( ServerKeyExchange )
4438 * ( CertificateRequest )
4439 * ServerHelloDone
4440 */
4441 case MBEDTLS_SSL_SERVER_HELLO:
4442 ret = ssl_write_server_hello( ssl );
4443 break;
4444
4445 case MBEDTLS_SSL_SERVER_CERTIFICATE:
4446 ret = mbedtls_ssl_write_certificate( ssl );
4447 break;
4448
4449 case MBEDTLS_SSL_SERVER_KEY_EXCHANGE:
4450 ret = ssl_write_server_key_exchange( ssl );
4451 break;
4452
4453 case MBEDTLS_SSL_CERTIFICATE_REQUEST:
4454 ret = ssl_write_certificate_request( ssl );
4455 break;
4456
4457 case MBEDTLS_SSL_SERVER_HELLO_DONE:
4458 ret = ssl_write_server_hello_done( ssl );
4459 break;
4460
4461 /*
4462 * <== ( Certificate/Alert )
4463 * ClientKeyExchange
4464 * ( CertificateVerify )
4465 * ChangeCipherSpec
4466 * Finished
4467 */
4468 case MBEDTLS_SSL_CLIENT_CERTIFICATE:
4469 ret = mbedtls_ssl_parse_certificate( ssl );
4470 break;
4471
4472 case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE:
4473 ret = ssl_parse_client_key_exchange( ssl );
4474 break;
4475
4476 case MBEDTLS_SSL_CERTIFICATE_VERIFY:
4477 ret = ssl_parse_certificate_verify( ssl );
4478 break;
4479
4480 case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC:
4481 ret = mbedtls_ssl_parse_change_cipher_spec( ssl );
4482 break;
4483
4484 case MBEDTLS_SSL_CLIENT_FINISHED:
4485 ret = mbedtls_ssl_parse_finished( ssl );
4486 break;
4487
4488 /*
4489 * ==> ( NewSessionTicket )
4490 * ChangeCipherSpec
4491 * Finished
4492 */
4493 case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC:
4494 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
4495 if( ssl->handshake->new_session_ticket != 0 )
4496 ret = ssl_write_new_session_ticket( ssl );
4497 else
4498 #endif
4499 ret = mbedtls_ssl_write_change_cipher_spec( ssl );
4500 break;
4501
4502 case MBEDTLS_SSL_SERVER_FINISHED:
4503 ret = mbedtls_ssl_write_finished( ssl );
4504 break;
4505
4506 case MBEDTLS_SSL_FLUSH_BUFFERS:
4507 MBEDTLS_SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
4508 ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP;
4509 break;
4510
4511 case MBEDTLS_SSL_HANDSHAKE_WRAPUP:
4512 mbedtls_ssl_handshake_wrapup( ssl );
4513 break;
4514
4515 default:
4516 MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
4517 return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
4518 }
4519
4520 return( ret );
4521 }
4522
mbedtls_ssl_conf_preference_order(mbedtls_ssl_config * conf,int order)4523 void mbedtls_ssl_conf_preference_order( mbedtls_ssl_config *conf, int order )
4524 {
4525 conf->respect_cli_pref = order;
4526 }
4527
4528 #endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_PROTO_TLS1_2 */
4529
