]>
Commit | Line | Data |
---|---|---|
25670f3e MC |
1 | /* |
2 | * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved. | |
3 | * | |
4 | * Licensed under the OpenSSL license (the "License"). You may not use | |
5 | * this file except in compliance with the License. You can obtain a copy | |
6 | * in the file LICENSE in the source distribution or at | |
7 | * https://www.openssl.org/source/license.html | |
8 | */ | |
9 | ||
10 | #include <openssl/ocsp.h> | |
11 | #include "../ssl_locl.h" | |
12 | #include "statem_locl.h" | |
13 | ||
14 | /* | |
15 | * Parse the client's renegotiation binding and abort if it's not right | |
16 | */ | |
17 | int tls_parse_clienthello_renegotiate(SSL *s, PACKET *pkt, int *al) | |
18 | { | |
19 | unsigned int ilen; | |
20 | const unsigned char *data; | |
21 | ||
22 | /* Parse the length byte */ | |
23 | if (!PACKET_get_1(pkt, &ilen) | |
24 | || !PACKET_get_bytes(pkt, &data, ilen)) { | |
25 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE, | |
26 | SSL_R_RENEGOTIATION_ENCODING_ERR); | |
27 | *al = SSL_AD_ILLEGAL_PARAMETER; | |
28 | return 0; | |
29 | } | |
30 | ||
31 | /* Check that the extension matches */ | |
32 | if (ilen != s->s3->previous_client_finished_len) { | |
33 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE, | |
34 | SSL_R_RENEGOTIATION_MISMATCH); | |
35 | *al = SSL_AD_HANDSHAKE_FAILURE; | |
36 | return 0; | |
37 | } | |
38 | ||
39 | if (memcmp(data, s->s3->previous_client_finished, | |
40 | s->s3->previous_client_finished_len)) { | |
41 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_RENEGOTIATE, | |
42 | SSL_R_RENEGOTIATION_MISMATCH); | |
43 | *al = SSL_AD_HANDSHAKE_FAILURE; | |
44 | return 0; | |
45 | } | |
46 | ||
47 | s->s3->send_connection_binding = 1; | |
48 | ||
49 | return 1; | |
50 | } | |
51 | ||
52 | int tls_parse_clienthello_server_name(SSL *s, PACKET *pkt, int *al) | |
53 | { | |
54 | unsigned int servname_type; | |
55 | PACKET sni, hostname; | |
56 | ||
57 | /*- | |
58 | * The servername extension is treated as follows: | |
59 | * | |
60 | * - Only the hostname type is supported with a maximum length of 255. | |
61 | * - The servername is rejected if too long or if it contains zeros, | |
62 | * in which case an fatal alert is generated. | |
63 | * - The servername field is maintained together with the session cache. | |
64 | * - When a session is resumed, the servername call back invoked in order | |
65 | * to allow the application to position itself to the right context. | |
66 | * - The servername is acknowledged if it is new for a session or when | |
67 | * it is identical to a previously used for the same session. | |
68 | * Applications can control the behaviour. They can at any time | |
69 | * set a 'desirable' servername for a new SSL object. This can be the | |
70 | * case for example with HTTPS when a Host: header field is received and | |
71 | * a renegotiation is requested. In this case, a possible servername | |
72 | * presented in the new client hello is only acknowledged if it matches | |
73 | * the value of the Host: field. | |
74 | * - Applications must use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION | |
75 | * if they provide for changing an explicit servername context for the | |
76 | * session, i.e. when the session has been established with a servername | |
77 | * extension. | |
78 | * - On session reconnect, the servername extension may be absent. | |
79 | * | |
80 | */ | |
81 | if (!PACKET_as_length_prefixed_2(pkt, &sni) | |
82 | /* ServerNameList must be at least 1 byte long. */ | |
83 | || PACKET_remaining(&sni) == 0) { | |
84 | *al = SSL_AD_DECODE_ERROR; | |
85 | return 0; | |
86 | } | |
87 | ||
88 | /* | |
89 | * Although the server_name extension was intended to be | |
90 | * extensible to new name types, RFC 4366 defined the | |
91 | * syntax inextensibility and OpenSSL 1.0.x parses it as | |
92 | * such. | |
93 | * RFC 6066 corrected the mistake but adding new name types | |
94 | * is nevertheless no longer feasible, so act as if no other | |
95 | * SNI types can exist, to simplify parsing. | |
96 | * | |
97 | * Also note that the RFC permits only one SNI value per type, | |
98 | * i.e., we can only have a single hostname. | |
99 | */ | |
100 | if (!PACKET_get_1(&sni, &servname_type) | |
101 | || servname_type != TLSEXT_NAMETYPE_host_name | |
102 | || !PACKET_as_length_prefixed_2(&sni, &hostname)) { | |
103 | *al = SSL_AD_DECODE_ERROR; | |
104 | return 0; | |
105 | } | |
106 | ||
107 | if (!s->hit) { | |
108 | if (PACKET_remaining(&hostname) > TLSEXT_MAXLEN_host_name) { | |
109 | *al = TLS1_AD_UNRECOGNIZED_NAME; | |
110 | return 0; | |
111 | } | |
112 | ||
113 | if (PACKET_contains_zero_byte(&hostname)) { | |
114 | *al = TLS1_AD_UNRECOGNIZED_NAME; | |
115 | return 0; | |
116 | } | |
117 | ||
118 | if (!PACKET_strndup(&hostname, &s->session->tlsext_hostname)) { | |
119 | *al = TLS1_AD_INTERNAL_ERROR; | |
120 | return 0; | |
121 | } | |
122 | ||
123 | s->servername_done = 1; | |
124 | } else { | |
125 | /* | |
126 | * TODO(openssl-team): if the SNI doesn't match, we MUST | |
127 | * fall back to a full handshake. | |
128 | */ | |
129 | s->servername_done = s->session->tlsext_hostname | |
130 | && PACKET_equal(&hostname, s->session->tlsext_hostname, | |
131 | strlen(s->session->tlsext_hostname)); | |
132 | } | |
133 | ||
134 | return 1; | |
135 | } | |
136 | ||
137 | #ifndef OPENSSL_NO_SRP | |
138 | int tls_parse_clienthello_srp(SSL *s, PACKET *pkt, int *al) | |
139 | { | |
140 | PACKET srp_I; | |
141 | ||
142 | if (!PACKET_as_length_prefixed_1(pkt, &srp_I) | |
143 | || PACKET_contains_zero_byte(&srp_I)) { | |
144 | *al = SSL_AD_DECODE_ERROR; | |
145 | return 0; | |
146 | } | |
147 | ||
148 | /* | |
149 | * TODO(openssl-team): currently, we re-authenticate the user | |
150 | * upon resumption. Instead, we MUST ignore the login. | |
151 | */ | |
152 | if (!PACKET_strndup(&srp_I, &s->srp_ctx.login)) { | |
153 | *al = TLS1_AD_INTERNAL_ERROR; | |
154 | return 0; | |
155 | } | |
156 | ||
157 | return 1; | |
158 | } | |
159 | #endif | |
160 | ||
161 | #ifndef OPENSSL_NO_EC | |
162 | int tls_parse_clienthello_ec_pt_formats(SSL *s, PACKET *pkt, int *al) | |
163 | { | |
164 | PACKET ec_point_format_list; | |
165 | ||
166 | if (!PACKET_as_length_prefixed_1(pkt, &ec_point_format_list) | |
167 | || PACKET_remaining(&ec_point_format_list) == 0) { | |
168 | *al = SSL_AD_DECODE_ERROR; | |
169 | return 0; | |
170 | } | |
171 | ||
172 | if (!s->hit) { | |
173 | if (!PACKET_memdup(&ec_point_format_list, | |
174 | &s->session->tlsext_ecpointformatlist, | |
175 | &s->session->tlsext_ecpointformatlist_length)) { | |
176 | *al = TLS1_AD_INTERNAL_ERROR; | |
177 | return 0; | |
178 | } | |
179 | } | |
180 | ||
181 | return 1; | |
182 | } | |
183 | #endif /* OPENSSL_NO_EC */ | |
184 | ||
185 | int tls_parse_clienthello_session_ticket(SSL *s, PACKET *pkt, int *al) | |
186 | { | |
187 | if (s->tls_session_ticket_ext_cb && | |
188 | !s->tls_session_ticket_ext_cb(s, PACKET_data(pkt), | |
189 | PACKET_remaining(pkt), | |
190 | s->tls_session_ticket_ext_cb_arg)) { | |
191 | *al = TLS1_AD_INTERNAL_ERROR; | |
192 | return 0; | |
193 | } | |
194 | ||
195 | return 1; | |
196 | } | |
197 | ||
198 | int tls_parse_clienthello_sig_algs(SSL *s, PACKET *pkt, int *al) | |
199 | { | |
200 | PACKET supported_sig_algs; | |
201 | ||
202 | if (!PACKET_as_length_prefixed_2(pkt, &supported_sig_algs) | |
203 | || (PACKET_remaining(&supported_sig_algs) % 2) != 0 | |
204 | || PACKET_remaining(&supported_sig_algs) == 0) { | |
205 | *al = SSL_AD_DECODE_ERROR; | |
206 | return 0; | |
207 | } | |
208 | ||
209 | if (!s->hit && !tls1_save_sigalgs(s, PACKET_data(&supported_sig_algs), | |
210 | PACKET_remaining(&supported_sig_algs))) { | |
211 | *al = TLS1_AD_INTERNAL_ERROR; | |
212 | return 0; | |
213 | } | |
214 | ||
215 | return 1; | |
216 | } | |
217 | ||
218 | int tls_parse_clienthello_status_request(SSL *s, PACKET *pkt, int *al) | |
219 | { | |
220 | if (!PACKET_get_1(pkt, (unsigned int *)&s->tlsext_status_type)) { | |
221 | *al = SSL_AD_DECODE_ERROR; | |
222 | return 0; | |
223 | } | |
224 | #ifndef OPENSSL_NO_OCSP | |
225 | if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) { | |
226 | const unsigned char *ext_data; | |
227 | PACKET responder_id_list, exts; | |
228 | if (!PACKET_get_length_prefixed_2 (pkt, &responder_id_list)) { | |
229 | *al = SSL_AD_DECODE_ERROR; | |
230 | return 0; | |
231 | } | |
232 | ||
233 | /* | |
234 | * We remove any OCSP_RESPIDs from a previous handshake | |
235 | * to prevent unbounded memory growth - CVE-2016-6304 | |
236 | */ | |
237 | sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids, OCSP_RESPID_free); | |
238 | if (PACKET_remaining(&responder_id_list) > 0) { | |
239 | s->tlsext_ocsp_ids = sk_OCSP_RESPID_new_null(); | |
240 | if (s->tlsext_ocsp_ids == NULL) { | |
241 | *al = SSL_AD_INTERNAL_ERROR; | |
242 | return 0; | |
243 | } | |
244 | } else { | |
245 | s->tlsext_ocsp_ids = NULL; | |
246 | } | |
247 | ||
248 | while (PACKET_remaining(&responder_id_list) > 0) { | |
249 | OCSP_RESPID *id; | |
250 | PACKET responder_id; | |
251 | const unsigned char *id_data; | |
252 | ||
253 | if (!PACKET_get_length_prefixed_2(&responder_id_list, | |
254 | &responder_id) | |
255 | || PACKET_remaining(&responder_id) == 0) { | |
256 | *al = SSL_AD_DECODE_ERROR; | |
257 | return 0; | |
258 | } | |
259 | ||
260 | id_data = PACKET_data(&responder_id); | |
261 | /* TODO(size_t): Convert d2i_* to size_t */ | |
262 | id = d2i_OCSP_RESPID(NULL, &id_data, | |
263 | (int)PACKET_remaining(&responder_id)); | |
264 | if (id == NULL) { | |
265 | *al = SSL_AD_DECODE_ERROR; | |
266 | return 0; | |
267 | } | |
268 | ||
269 | if (id_data != PACKET_end(&responder_id)) { | |
270 | OCSP_RESPID_free(id); | |
271 | *al = SSL_AD_DECODE_ERROR; | |
272 | return 0; | |
273 | } | |
274 | ||
275 | if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id)) { | |
276 | OCSP_RESPID_free(id); | |
277 | *al = SSL_AD_INTERNAL_ERROR; | |
278 | return 0; | |
279 | } | |
280 | } | |
281 | ||
282 | /* Read in request_extensions */ | |
283 | if (!PACKET_as_length_prefixed_2(pkt, &exts)) { | |
284 | *al = SSL_AD_DECODE_ERROR; | |
285 | return 0; | |
286 | } | |
287 | ||
288 | if (PACKET_remaining(&exts) > 0) { | |
289 | ext_data = PACKET_data(&exts); | |
290 | sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts, | |
291 | X509_EXTENSION_free); | |
292 | s->tlsext_ocsp_exts = | |
293 | d2i_X509_EXTENSIONS(NULL, &ext_data, | |
294 | (int)PACKET_remaining(&exts)); | |
295 | if (s->tlsext_ocsp_exts == NULL || ext_data != PACKET_end(&exts)) { | |
296 | *al = SSL_AD_DECODE_ERROR; | |
297 | return 0; | |
298 | } | |
299 | } | |
300 | } else | |
301 | #endif | |
302 | { | |
303 | /* | |
304 | * We don't know what to do with any other type so ignore it. | |
305 | */ | |
306 | s->tlsext_status_type = -1; | |
307 | } | |
308 | ||
309 | return 1; | |
310 | } | |
311 | ||
312 | #ifndef OPENSSL_NO_NEXTPROTONEG | |
313 | int tls_parse_clienthello_npn(SSL *s, PACKET *pkt, int *al) | |
314 | { | |
315 | if (s->s3->tmp.finish_md_len == 0) { | |
316 | /*- | |
317 | * We shouldn't accept this extension on a | |
318 | * renegotiation. | |
319 | * | |
320 | * s->new_session will be set on renegotiation, but we | |
321 | * probably shouldn't rely that it couldn't be set on | |
322 | * the initial renegotiation too in certain cases (when | |
323 | * there's some other reason to disallow resuming an | |
324 | * earlier session -- the current code won't be doing | |
325 | * anything like that, but this might change). | |
326 | * | |
327 | * A valid sign that there's been a previous handshake | |
328 | * in this connection is if s->s3->tmp.finish_md_len > | |
329 | * 0. (We are talking about a check that will happen | |
330 | * in the Hello protocol round, well before a new | |
331 | * Finished message could have been computed.) | |
332 | */ | |
333 | s->s3->next_proto_neg_seen = 1; | |
334 | } | |
335 | ||
336 | return 1; | |
337 | } | |
338 | #endif | |
339 | ||
340 | /* | |
341 | * Save the ALPN extension in a ClientHello. | |
342 | * pkt: the contents of the ALPN extension, not including type and length. | |
343 | * al: a pointer to the alert value to send in the event of a failure. | |
344 | * returns: 1 on success, 0 on error. | |
345 | */ | |
346 | int tls_parse_clienthello_alpn(SSL *s, PACKET *pkt, int *al) | |
347 | { | |
348 | PACKET protocol_list, save_protocol_list, protocol; | |
349 | ||
350 | if (s->s3->tmp.finish_md_len != 0) | |
351 | return 1; | |
352 | ||
353 | if (!PACKET_as_length_prefixed_2(pkt, &protocol_list) | |
354 | || PACKET_remaining(&protocol_list) < 2) { | |
355 | *al = SSL_AD_DECODE_ERROR; | |
356 | return 0; | |
357 | } | |
358 | ||
359 | save_protocol_list = protocol_list; | |
360 | do { | |
361 | /* Protocol names can't be empty. */ | |
362 | if (!PACKET_get_length_prefixed_1(&protocol_list, &protocol) | |
363 | || PACKET_remaining(&protocol) == 0) { | |
364 | *al = SSL_AD_DECODE_ERROR; | |
365 | return 0; | |
366 | } | |
367 | } while (PACKET_remaining(&protocol_list) != 0); | |
368 | ||
369 | if (!PACKET_memdup(&save_protocol_list, | |
370 | &s->s3->alpn_proposed, &s->s3->alpn_proposed_len)) { | |
371 | *al = TLS1_AD_INTERNAL_ERROR; | |
372 | return 0; | |
373 | } | |
374 | ||
375 | return 1; | |
376 | } | |
377 | ||
378 | #ifndef OPENSSL_NO_SRTP | |
379 | int tls_parse_clienthello_use_srtp(SSL *s, PACKET *pkt, int *al) | |
380 | { | |
381 | SRTP_PROTECTION_PROFILE *sprof; | |
382 | STACK_OF(SRTP_PROTECTION_PROFILE) *srvr; | |
383 | unsigned int ct, mki_len, id; | |
384 | int i, srtp_pref; | |
385 | PACKET subpkt; | |
386 | ||
387 | /* Ignore this if we have no SRTP profiles */ | |
388 | if (SSL_get_srtp_profiles(s) == NULL) | |
389 | return 1; | |
390 | ||
391 | /* Pull off the length of the cipher suite list and check it is even */ | |
392 | if (!PACKET_get_net_2(pkt, &ct) | |
393 | || (ct & 1) != 0 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) { | |
394 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP, | |
395 | SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); | |
396 | *al = SSL_AD_DECODE_ERROR; | |
397 | return 0; | |
398 | } | |
399 | ||
400 | srvr = SSL_get_srtp_profiles(s); | |
401 | s->srtp_profile = NULL; | |
402 | /* Search all profiles for a match initially */ | |
403 | srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr); | |
404 | ||
405 | while (PACKET_remaining(&subpkt)) { | |
406 | if (!PACKET_get_net_2(&subpkt, &id)) { | |
407 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP, | |
408 | SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); | |
409 | *al = SSL_AD_DECODE_ERROR; | |
410 | return 0; | |
411 | } | |
412 | ||
413 | /* | |
414 | * Only look for match in profiles of higher preference than | |
415 | * current match. | |
416 | * If no profiles have been have been configured then this | |
417 | * does nothing. | |
418 | */ | |
419 | for (i = 0; i < srtp_pref; i++) { | |
420 | sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i); | |
421 | if (sprof->id == id) { | |
422 | s->srtp_profile = sprof; | |
423 | srtp_pref = i; | |
424 | break; | |
425 | } | |
426 | } | |
427 | } | |
428 | ||
429 | /* | |
430 | * Now extract the MKI value as a sanity check, but discard it for now | |
431 | */ | |
432 | if (!PACKET_get_1(pkt, &mki_len)) { | |
433 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP, | |
434 | SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); | |
435 | *al = SSL_AD_DECODE_ERROR; | |
436 | return 0; | |
437 | } | |
438 | ||
439 | if (!PACKET_forward(pkt, mki_len) | |
440 | || PACKET_remaining(pkt)) { | |
441 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_USE_SRTP, SSL_R_BAD_SRTP_MKI_VALUE); | |
442 | *al = SSL_AD_DECODE_ERROR; | |
443 | return 0; | |
444 | } | |
445 | ||
446 | return 1; | |
447 | } | |
448 | #endif | |
449 | ||
450 | int tls_parse_clienthello_etm(SSL *s, PACKET *pkt, int *al) | |
451 | { | |
452 | if (!(s->options & SSL_OP_NO_ENCRYPT_THEN_MAC)) | |
453 | s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC; | |
454 | ||
455 | return 1; | |
456 | } | |
457 | ||
458 | /* | |
459 | * Checks a list of |groups| to determine if the |group_id| is in it. If it is | |
460 | * and |checkallow| is 1 then additionally check if the group is allowed to be | |
461 | * used. Returns 1 if the group is in the list (and allowed if |checkallow| is | |
462 | * 1) or 0 otherwise. | |
463 | */ | |
464 | static int check_in_list(SSL *s, unsigned int group_id, | |
465 | const unsigned char *groups, size_t num_groups, | |
466 | int checkallow) | |
467 | { | |
468 | size_t i; | |
469 | ||
470 | if (groups == NULL || num_groups == 0) | |
471 | return 0; | |
472 | ||
473 | for (i = 0; i < num_groups; i++, groups += 2) { | |
474 | unsigned int share_id = (groups[0] << 8) | (groups[1]); | |
475 | ||
476 | if (group_id == share_id | |
477 | && (!checkallow || tls_curve_allowed(s, groups, | |
478 | SSL_SECOP_CURVE_CHECK))) { | |
479 | break; | |
480 | } | |
481 | } | |
482 | ||
483 | /* If i == num_groups then not in the list */ | |
484 | return i < num_groups; | |
485 | } | |
486 | ||
487 | /* | |
488 | * Process a key_share extension received in the ClientHello. |pkt| contains | |
489 | * the raw PACKET data for the extension. Returns 1 on success or 0 on failure. | |
490 | * If a failure occurs then |*al| is set to an appropriate alert value. | |
491 | */ | |
492 | int tls_parse_clienthello_key_share(SSL *s, PACKET *pkt, int *al) | |
493 | { | |
494 | unsigned int group_id; | |
495 | PACKET key_share_list, encoded_pt; | |
496 | const unsigned char *clntcurves, *srvrcurves; | |
497 | size_t clnt_num_curves, srvr_num_curves; | |
498 | int group_nid, found = 0; | |
499 | unsigned int curve_flags; | |
500 | ||
501 | if (s->hit) | |
502 | return 1; | |
503 | ||
504 | /* Sanity check */ | |
505 | if (s->s3->peer_tmp != NULL) { | |
506 | *al = SSL_AD_INTERNAL_ERROR; | |
507 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR); | |
508 | return 0; | |
509 | } | |
510 | ||
511 | if (!PACKET_as_length_prefixed_2(pkt, &key_share_list)) { | |
512 | *al = SSL_AD_HANDSHAKE_FAILURE; | |
513 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_LENGTH_MISMATCH); | |
514 | return 0; | |
515 | } | |
516 | ||
517 | /* Get our list of supported curves */ | |
518 | if (!tls1_get_curvelist(s, 0, &srvrcurves, &srvr_num_curves)) { | |
519 | *al = SSL_AD_INTERNAL_ERROR; | |
520 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR); | |
521 | return 0; | |
522 | } | |
523 | ||
524 | /* Get the clients list of supported curves */ | |
525 | if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) { | |
526 | *al = SSL_AD_INTERNAL_ERROR; | |
527 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_INTERNAL_ERROR); | |
528 | return 0; | |
529 | } | |
530 | ||
531 | while (PACKET_remaining(&key_share_list) > 0) { | |
532 | if (!PACKET_get_net_2(&key_share_list, &group_id) | |
533 | || !PACKET_get_length_prefixed_2(&key_share_list, &encoded_pt) | |
534 | || PACKET_remaining(&encoded_pt) == 0) { | |
535 | *al = SSL_AD_HANDSHAKE_FAILURE; | |
536 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, | |
537 | SSL_R_LENGTH_MISMATCH); | |
538 | return 0; | |
539 | } | |
540 | ||
541 | /* | |
542 | * If we already found a suitable key_share we loop through the | |
543 | * rest to verify the structure, but don't process them. | |
544 | */ | |
545 | if (found) | |
546 | continue; | |
547 | ||
548 | /* Check if this share is in supported_groups sent from client */ | |
549 | if (!check_in_list(s, group_id, clntcurves, clnt_num_curves, 0)) { | |
550 | *al = SSL_AD_HANDSHAKE_FAILURE; | |
551 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_KEY_SHARE); | |
552 | return 0; | |
553 | } | |
554 | ||
555 | /* Check if this share is for a group we can use */ | |
556 | if (!check_in_list(s, group_id, srvrcurves, srvr_num_curves, 1)) { | |
557 | /* Share not suitable */ | |
558 | continue; | |
559 | } | |
560 | ||
561 | group_nid = tls1_ec_curve_id2nid(group_id, &curve_flags); | |
562 | ||
563 | if (group_nid == 0) { | |
564 | *al = SSL_AD_INTERNAL_ERROR; | |
565 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, | |
566 | SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS); | |
567 | return 0; | |
568 | } | |
569 | ||
570 | if ((curve_flags & TLS_CURVE_TYPE) == TLS_CURVE_CUSTOM) { | |
571 | /* Can happen for some curves, e.g. X25519 */ | |
572 | EVP_PKEY *key = EVP_PKEY_new(); | |
573 | ||
574 | if (key == NULL || !EVP_PKEY_set_type(key, group_nid)) { | |
575 | *al = SSL_AD_INTERNAL_ERROR; | |
576 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB); | |
577 | EVP_PKEY_free(key); | |
578 | return 0; | |
579 | } | |
580 | s->s3->peer_tmp = key; | |
581 | } else { | |
582 | /* Set up EVP_PKEY with named curve as parameters */ | |
583 | EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL); | |
584 | if (pctx == NULL | |
585 | || EVP_PKEY_paramgen_init(pctx) <= 0 | |
586 | || EVP_PKEY_CTX_set_ec_paramgen_curve_nid(pctx, | |
587 | group_nid) <= 0 | |
588 | || EVP_PKEY_paramgen(pctx, &s->s3->peer_tmp) <= 0) { | |
589 | *al = SSL_AD_INTERNAL_ERROR; | |
590 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, ERR_R_EVP_LIB); | |
591 | EVP_PKEY_CTX_free(pctx); | |
592 | return 0; | |
593 | } | |
594 | EVP_PKEY_CTX_free(pctx); | |
595 | pctx = NULL; | |
596 | } | |
597 | s->s3->group_id = group_id; | |
598 | ||
599 | if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp, | |
600 | PACKET_data(&encoded_pt), | |
601 | PACKET_remaining(&encoded_pt))) { | |
602 | *al = SSL_AD_DECODE_ERROR; | |
603 | SSLerr(SSL_F_TLS_PARSE_CLIENTHELLO_KEY_SHARE, SSL_R_BAD_ECPOINT); | |
604 | return 0; | |
605 | } | |
606 | ||
607 | found = 1; | |
608 | } | |
609 | ||
610 | return 1; | |
611 | } | |
612 | ||
613 | #ifndef OPENSSL_NO_EC | |
614 | int tls_parse_clienthello_supported_groups(SSL *s, PACKET *pkt, int *al) | |
615 | { | |
616 | PACKET supported_groups_list; | |
617 | ||
618 | /* Each group is 2 bytes and we must have at least 1. */ | |
619 | if (!PACKET_as_length_prefixed_2(pkt, &supported_groups_list) | |
620 | || PACKET_remaining(&supported_groups_list) == 0 | |
621 | || (PACKET_remaining(&supported_groups_list) % 2) != 0) { | |
622 | *al = SSL_AD_DECODE_ERROR; | |
623 | return 0; | |
624 | } | |
625 | ||
626 | if (!s->hit | |
627 | && !PACKET_memdup(&supported_groups_list, | |
628 | &s->session->tlsext_supportedgroupslist, | |
629 | &s->session->tlsext_supportedgroupslist_length)) { | |
630 | *al = SSL_AD_DECODE_ERROR; | |
631 | return 0; | |
632 | } | |
633 | ||
634 | return 1; | |
635 | } | |
636 | #endif | |
637 | ||
638 | int tls_parse_clienthello_ems(SSL *s, PACKET *pkt, int *al) | |
639 | { | |
640 | /* The extension must always be empty */ | |
641 | if (PACKET_remaining(pkt) != 0) { | |
642 | *al = SSL_AD_DECODE_ERROR; | |
643 | return 0; | |
644 | } | |
645 | ||
646 | s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS; | |
647 | ||
648 | return 1; | |
649 | } |