1/*
2 * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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 <string.h>
11#include "internal/nelem.h"
12#include "internal/cryptlib.h"
13#include "../ssl_local.h"
14#include "statem_local.h"
15#include "internal/cryptlib.h"
16
17static int final_renegotiate(SSL *s, unsigned int context, int sent);
18static int init_server_name(SSL *s, unsigned int context);
19static int final_server_name(SSL *s, unsigned int context, int sent);
20#ifndef OPENSSL_NO_EC
21static int final_ec_pt_formats(SSL *s, unsigned int context, int sent);
22#endif
23static int init_session_ticket(SSL *s, unsigned int context);
24#ifndef OPENSSL_NO_OCSP
25static int init_status_request(SSL *s, unsigned int context);
26#endif
27#ifndef OPENSSL_NO_NEXTPROTONEG
28static int init_npn(SSL *s, unsigned int context);
29#endif
30static int init_alpn(SSL *s, unsigned int context);
31static int final_alpn(SSL *s, unsigned int context, int sent);
32static int init_sig_algs_cert(SSL *s, unsigned int context);
33static int init_sig_algs(SSL *s, unsigned int context);
34static int init_certificate_authorities(SSL *s, unsigned int context);
35static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
36 unsigned int context,
37 X509 *x,
38 size_t chainidx);
39static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
40 unsigned int context, X509 *x,
41 size_t chainidx);
42#ifndef OPENSSL_NO_SRP
43static int init_srp(SSL *s, unsigned int context);
44#endif
45static int init_etm(SSL *s, unsigned int context);
46static int init_ems(SSL *s, unsigned int context);
47static int final_ems(SSL *s, unsigned int context, int sent);
48static int init_psk_kex_modes(SSL *s, unsigned int context);
49static int final_key_share(SSL *s, unsigned int context, int sent);
50#ifndef OPENSSL_NO_SRTP
51static int init_srtp(SSL *s, unsigned int context);
52#endif
53static int final_sig_algs(SSL *s, unsigned int context, int sent);
54static int final_early_data(SSL *s, unsigned int context, int sent);
55static int final_maxfragmentlen(SSL *s, unsigned int context, int sent);
56static int init_post_handshake_auth(SSL *s, unsigned int context);
57
58/* Structure to define a built-in extension */
59typedef struct extensions_definition_st {
60 /* The defined type for the extension */
61 unsigned int type;
62 /*
63 * The context that this extension applies to, e.g. what messages and
64 * protocol versions
65 */
66 unsigned int context;
67 /*
68 * Initialise extension before parsing. Always called for relevant contexts
69 * even if extension not present
70 */
71 int (*init)(SSL *s, unsigned int context);
72 /* Parse extension sent from client to server */
73 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
74 size_t chainidx);
75 /* Parse extension send from server to client */
76 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
77 size_t chainidx);
78 /* Construct extension sent from server to client */
79 EXT_RETURN (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context,
80 X509 *x, size_t chainidx);
81 /* Construct extension sent from client to server */
82 EXT_RETURN (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context,
83 X509 *x, size_t chainidx);
84 /*
85 * Finalise extension after parsing. Always called where an extensions was
86 * initialised even if the extension was not present. |sent| is set to 1 if
87 * the extension was seen, or 0 otherwise.
88 */
89 int (*final)(SSL *s, unsigned int context, int sent);
90} EXTENSION_DEFINITION;
91
92/*
93 * Definitions of all built-in extensions. NOTE: Changes in the number or order
94 * of these extensions should be mirrored with equivalent changes to the
95 * indexes ( TLSEXT_IDX_* ) defined in ssl_local.h.
96 * Each extension has an initialiser, a client and
97 * server side parser and a finaliser. The initialiser is called (if the
98 * extension is relevant to the given context) even if we did not see the
99 * extension in the message that we received. The parser functions are only
100 * called if we see the extension in the message. The finalisers are always
101 * called if the initialiser was called.
102 * There are also server and client side constructor functions which are always
103 * called during message construction if the extension is relevant for the
104 * given context.
105 * The initialisation, parsing, finalisation and construction functions are
106 * always called in the order defined in this list. Some extensions may depend
107 * on others having been processed first, so the order of this list is
108 * significant.
109 * The extension context is defined by a series of flags which specify which
110 * messages the extension is relevant to. These flags also specify whether the
111 * extension is relevant to a particular protocol or protocol version.
112 *
113 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
114 *
115 * NOTE: WebSphere Application Server 7+ cannot handle empty extensions at
116 * the end, keep these extensions before signature_algorithm.
117 */
118#define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
119static const EXTENSION_DEFINITION ext_defs[] = {
120 {
121 TLSEXT_TYPE_renegotiate,
122 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
123 | SSL_EXT_SSL3_ALLOWED | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
124 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
125 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
126 final_renegotiate
127 },
128 {
129 TLSEXT_TYPE_server_name,
130 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
131 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
132 init_server_name,
133 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
134 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
135 final_server_name
136 },
137 {
138 TLSEXT_TYPE_max_fragment_length,
139 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
140 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
141 NULL, tls_parse_ctos_maxfragmentlen, tls_parse_stoc_maxfragmentlen,
142 tls_construct_stoc_maxfragmentlen, tls_construct_ctos_maxfragmentlen,
143 final_maxfragmentlen
144 },
145#ifndef OPENSSL_NO_SRP
146 {
147 TLSEXT_TYPE_srp,
148 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
149 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
150 },
151#else
152 INVALID_EXTENSION,
153#endif
154#ifndef OPENSSL_NO_EC
155 {
156 TLSEXT_TYPE_ec_point_formats,
157 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
158 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
159 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
160 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
161 final_ec_pt_formats
162 },
163#else
164 INVALID_EXTENSION,
165#endif
166#if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
167 {
168 /*
169 * "supported_groups" is spread across several specifications.
170 * It was originally specified as "elliptic_curves" in RFC 4492,
171 * and broadened to include named FFDH groups by RFC 7919.
172 * Both RFCs 4492 and 7919 do not include a provision for the server
173 * to indicate to the client the complete list of groups supported
174 * by the server, with the server instead just indicating the
175 * selected group for this connection in the ServerKeyExchange
176 * message. TLS 1.3 adds a scheme for the server to indicate
177 * to the client its list of supported groups in the
178 * EncryptedExtensions message, but none of the relevant
179 * specifications permit sending supported_groups in the ServerHello.
180 * Nonetheless (possibly due to the close proximity to the
181 * "ec_point_formats" extension, which is allowed in the ServerHello),
182 * there are several servers that send this extension in the
183 * ServerHello anyway. Up to and including the 1.1.0 release,
184 * we did not check for the presence of nonpermitted extensions,
185 * so to avoid a regression, we must permit this extension in the
186 * TLS 1.2 ServerHello as well.
187 *
188 * Note that there is no tls_parse_stoc_supported_groups function,
189 * so we do not perform any additional parsing, validation, or
190 * processing on the server's group list -- this is just a minimal
191 * change to preserve compatibility with these misbehaving servers.
192 */
193 TLSEXT_TYPE_supported_groups,
194 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
195 | SSL_EXT_TLS1_2_SERVER_HELLO,
196 NULL, tls_parse_ctos_supported_groups, NULL,
197 tls_construct_stoc_supported_groups,
198 tls_construct_ctos_supported_groups, NULL
199 },
200#else
201 INVALID_EXTENSION,
202#endif
203 {
204 TLSEXT_TYPE_session_ticket,
205 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
206 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
207 init_session_ticket, tls_parse_ctos_session_ticket,
208 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
209 tls_construct_ctos_session_ticket, NULL
210 },
211#ifndef OPENSSL_NO_OCSP
212 {
213 TLSEXT_TYPE_status_request,
214 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
215 | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
216 init_status_request, tls_parse_ctos_status_request,
217 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
218 tls_construct_ctos_status_request, NULL
219 },
220#else
221 INVALID_EXTENSION,
222#endif
223#ifndef OPENSSL_NO_NEXTPROTONEG
224 {
225 TLSEXT_TYPE_next_proto_neg,
226 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
227 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
228 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
229 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
230 },
231#else
232 INVALID_EXTENSION,
233#endif
234 {
235 /*
236 * Must appear in this list after server_name so that finalisation
237 * happens after server_name callbacks
238 */
239 TLSEXT_TYPE_application_layer_protocol_negotiation,
240 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
241 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
242 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
243 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
244 },
245#ifndef OPENSSL_NO_SRTP
246 {
247 TLSEXT_TYPE_use_srtp,
248 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
249 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS | SSL_EXT_DTLS_ONLY,
250 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
251 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
252 },
253#else
254 INVALID_EXTENSION,
255#endif
256 {
257 TLSEXT_TYPE_encrypt_then_mac,
258 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
259 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
260 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
261 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
262 },
263#ifndef OPENSSL_NO_CT
264 {
265 TLSEXT_TYPE_signed_certificate_timestamp,
266 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
267 | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
268 NULL,
269 /*
270 * No server side support for this, but can be provided by a custom
271 * extension. This is an exception to the rule that custom extensions
272 * cannot override built in ones.
273 */
274 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
275 },
276#else
277 INVALID_EXTENSION,
278#endif
279 {
280 TLSEXT_TYPE_extended_master_secret,
281 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
282 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
283 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
284 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
285 },
286 {
287 TLSEXT_TYPE_signature_algorithms_cert,
288 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
289 init_sig_algs_cert, tls_parse_ctos_sig_algs_cert,
290 tls_parse_ctos_sig_algs_cert,
291 /* We do not generate signature_algorithms_cert at present. */
292 NULL, NULL, NULL
293 },
294 {
295 TLSEXT_TYPE_post_handshake_auth,
296 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ONLY,
297 init_post_handshake_auth,
298 tls_parse_ctos_post_handshake_auth, NULL,
299 NULL, tls_construct_ctos_post_handshake_auth,
300 NULL,
301 },
302 {
303 TLSEXT_TYPE_signature_algorithms,
304 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
305 init_sig_algs, tls_parse_ctos_sig_algs,
306 tls_parse_ctos_sig_algs, tls_construct_ctos_sig_algs,
307 tls_construct_ctos_sig_algs, final_sig_algs
308 },
309 {
310 TLSEXT_TYPE_supported_versions,
311 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
312 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY,
313 NULL,
314 /* Processed inline as part of version selection */
315 NULL, tls_parse_stoc_supported_versions,
316 tls_construct_stoc_supported_versions,
317 tls_construct_ctos_supported_versions, NULL
318 },
319 {
320 TLSEXT_TYPE_psk_kex_modes,
321 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY
322 | SSL_EXT_TLS1_3_ONLY,
323 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
324 tls_construct_ctos_psk_kex_modes, NULL
325 },
326 {
327 /*
328 * Must be in this list after supported_groups. We need that to have
329 * been parsed before we do this one.
330 */
331 TLSEXT_TYPE_key_share,
332 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
333 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY
334 | SSL_EXT_TLS1_3_ONLY,
335 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
336 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
337 final_key_share
338 },
339 {
340 /* Must be after key_share */
341 TLSEXT_TYPE_cookie,
342 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
343 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
344 NULL, tls_parse_ctos_cookie, tls_parse_stoc_cookie,
345 tls_construct_stoc_cookie, tls_construct_ctos_cookie, NULL
346 },
347 {
348 /*
349 * Special unsolicited ServerHello extension only used when
350 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set. We allow it in a ClientHello but
351 * ignore it.
352 */
353 TLSEXT_TYPE_cryptopro_bug,
354 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
355 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
356 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
357 },
358 {
359 TLSEXT_TYPE_early_data,
360 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
361 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET | SSL_EXT_TLS1_3_ONLY,
362 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data,
363 tls_construct_stoc_early_data, tls_construct_ctos_early_data,
364 final_early_data
365 },
366 {
367 TLSEXT_TYPE_certificate_authorities,
368 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
369 | SSL_EXT_TLS1_3_ONLY,
370 init_certificate_authorities,
371 tls_parse_certificate_authorities, tls_parse_certificate_authorities,
372 tls_construct_certificate_authorities,
373 tls_construct_certificate_authorities, NULL,
374 },
375 {
376 /* Must be immediately before pre_shared_key */
377 TLSEXT_TYPE_padding,
378 SSL_EXT_CLIENT_HELLO,
379 NULL,
380 /* We send this, but don't read it */
381 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
382 },
383 {
384 /* Required by the TLSv1.3 spec to always be the last extension */
385 TLSEXT_TYPE_psk,
386 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
387 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
388 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
389 tls_construct_ctos_psk, NULL
390 }
391};
392
393/* Check whether an extension's context matches the current context */
394static int validate_context(SSL *s, unsigned int extctx, unsigned int thisctx)
395{
396 /* Check we're allowed to use this extension in this context */
397 if ((thisctx & extctx) == 0)
398 return 0;
399
400 if (SSL_IS_DTLS(s)) {
401 if ((extctx & SSL_EXT_TLS_ONLY) != 0)
402 return 0;
403 } else if ((extctx & SSL_EXT_DTLS_ONLY) != 0) {
404 return 0;
405 }
406
407 return 1;
408}
409
410int tls_validate_all_contexts(SSL *s, unsigned int thisctx, RAW_EXTENSION *exts)
411{
412 size_t i, num_exts, builtin_num = OSSL_NELEM(ext_defs), offset;
413 RAW_EXTENSION *thisext;
414 unsigned int context;
415 ENDPOINT role = ENDPOINT_BOTH;
416
417 if ((thisctx & SSL_EXT_CLIENT_HELLO) != 0)
418 role = ENDPOINT_SERVER;
419 else if ((thisctx & SSL_EXT_TLS1_2_SERVER_HELLO) != 0)
420 role = ENDPOINT_CLIENT;
421
422 /* Calculate the number of extensions in the extensions list */
423 num_exts = builtin_num + s->cert->custext.meths_count;
424
425 for (thisext = exts, i = 0; i < num_exts; i++, thisext++) {
426 if (!thisext->present)
427 continue;
428
429 if (i < builtin_num) {
430 context = ext_defs[i].context;
431 } else {
432 custom_ext_method *meth = NULL;
433
434 meth = custom_ext_find(&s->cert->custext, role, thisext->type,
435 &offset);
436 if (!ossl_assert(meth != NULL))
437 return 0;
438 context = meth->context;
439 }
440
441 if (!validate_context(s, context, thisctx))
442 return 0;
443 }
444
445 return 1;
446}
447
448/*
449 * Verify whether we are allowed to use the extension |type| in the current
450 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
451 * indicate the extension is not allowed. If returning 1 then |*found| is set to
452 * the definition for the extension we found.
453 */
454static int verify_extension(SSL *s, unsigned int context, unsigned int type,
455 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
456 RAW_EXTENSION **found)
457{
458 size_t i;
459 size_t builtin_num = OSSL_NELEM(ext_defs);
460 const EXTENSION_DEFINITION *thisext;
461
462 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
463 if (type == thisext->type) {
464 if (!validate_context(s, thisext->context, context))
465 return 0;
466
467 *found = &rawexlist[i];
468 return 1;
469 }
470 }
471
472 /* Check the custom extensions */
473 if (meths != NULL) {
474 size_t offset = 0;
475 ENDPOINT role = ENDPOINT_BOTH;
476 custom_ext_method *meth = NULL;
477
478 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
479 role = ENDPOINT_SERVER;
480 else if ((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0)
481 role = ENDPOINT_CLIENT;
482
483 meth = custom_ext_find(meths, role, type, &offset);
484 if (meth != NULL) {
485 if (!validate_context(s, meth->context, context))
486 return 0;
487 *found = &rawexlist[offset + builtin_num];
488 return 1;
489 }
490 }
491
492 /* Unknown extension. We allow it */
493 *found = NULL;
494 return 1;
495}
496
497/*
498 * Check whether the context defined for an extension |extctx| means whether
499 * the extension is relevant for the current context |thisctx| or not. Returns
500 * 1 if the extension is relevant for this context, and 0 otherwise
501 */
502int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx)
503{
504 int is_tls13;
505
506 /*
507 * For HRR we haven't selected the version yet but we know it will be
508 * TLSv1.3
509 */
510 if ((thisctx & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0)
511 is_tls13 = 1;
512 else
513 is_tls13 = SSL_IS_TLS13(s);
514
515 if ((SSL_IS_DTLS(s)
516 && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0)
517 || (s->version == SSL3_VERSION
518 && (extctx & SSL_EXT_SSL3_ALLOWED) == 0)
519 /*
520 * Note that SSL_IS_TLS13() means "TLS 1.3 has been negotiated",
521 * which is never true when generating the ClientHello.
522 * However, version negotiation *has* occurred by the time the
523 * ClientHello extensions are being parsed.
524 * Be careful to allow TLS 1.3-only extensions when generating
525 * the ClientHello.
526 */
527 || (is_tls13 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
528 || (!is_tls13 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0
529 && (thisctx & SSL_EXT_CLIENT_HELLO) == 0)
530 || (s->server && !is_tls13 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0)
531 || (s->hit && (extctx & SSL_EXT_IGNORE_ON_RESUMPTION) != 0))
532 return 0;
533 return 1;
534}
535
536/*
537 * Gather a list of all the extensions from the data in |packet]. |context|
538 * tells us which message this extension is for. The raw extension data is
539 * stored in |*res| on success. We don't actually process the content of the
540 * extensions yet, except to check their types. This function also runs the
541 * initialiser functions for all known extensions if |init| is nonzero (whether
542 * we have collected them or not). If successful the caller is responsible for
543 * freeing the contents of |*res|.
544 *
545 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
546 * more than one extension of the same type in a ClientHello or ServerHello.
547 * This function returns 1 if all extensions are unique and we have parsed their
548 * types, and 0 if the extensions contain duplicates, could not be successfully
549 * found, or an internal error occurred. We only check duplicates for
550 * extensions that we know about. We ignore others.
551 */
552int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
553 RAW_EXTENSION **res, size_t *len, int init)
554{
555 PACKET extensions = *packet;
556 size_t i = 0;
557 size_t num_exts;
558 custom_ext_methods *exts = &s->cert->custext;
559 RAW_EXTENSION *raw_extensions = NULL;
560 const EXTENSION_DEFINITION *thisexd;
561
562 *res = NULL;
563
564 /*
565 * Initialise server side custom extensions. Client side is done during
566 * construction of extensions for the ClientHello.
567 */
568 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
569 custom_ext_init(&s->cert->custext);
570
571 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
572 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
573 if (raw_extensions == NULL) {
574 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_COLLECT_EXTENSIONS,
575 ERR_R_MALLOC_FAILURE);
576 return 0;
577 }
578
579 i = 0;
580 while (PACKET_remaining(&extensions) > 0) {
581 unsigned int type, idx;
582 PACKET extension;
583 RAW_EXTENSION *thisex;
584
585 if (!PACKET_get_net_2(&extensions, &type) ||
586 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
587 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_COLLECT_EXTENSIONS,
588 SSL_R_BAD_EXTENSION);
589 goto err;
590 }
591 /*
592 * Verify this extension is allowed. We only check duplicates for
593 * extensions that we recognise. We also have a special case for the
594 * PSK extension, which must be the last one in the ClientHello.
595 */
596 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
597 || (thisex != NULL && thisex->present == 1)
598 || (type == TLSEXT_TYPE_psk
599 && (context & SSL_EXT_CLIENT_HELLO) != 0
600 && PACKET_remaining(&extensions) != 0)) {
601 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_COLLECT_EXTENSIONS,
602 SSL_R_BAD_EXTENSION);
603 goto err;
604 }
605 idx = thisex - raw_extensions;
606 /*-
607 * Check that we requested this extension (if appropriate). Requests can
608 * be sent in the ClientHello and CertificateRequest. Unsolicited
609 * extensions can be sent in the NewSessionTicket. We only do this for
610 * the built-in extensions. Custom extensions have a different but
611 * similar check elsewhere.
612 * Special cases:
613 * - The HRR cookie extension is unsolicited
614 * - The renegotiate extension is unsolicited (the client signals
615 * support via an SCSV)
616 * - The signed_certificate_timestamp extension can be provided by a
617 * custom extension or by the built-in version. We let the extension
618 * itself handle unsolicited response checks.
619 */
620 if (idx < OSSL_NELEM(ext_defs)
621 && (context & (SSL_EXT_CLIENT_HELLO
622 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
623 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) == 0
624 && type != TLSEXT_TYPE_cookie
625 && type != TLSEXT_TYPE_renegotiate
626 && type != TLSEXT_TYPE_signed_certificate_timestamp
627 && (s->ext.extflags[idx] & SSL_EXT_FLAG_SENT) == 0
628#ifndef OPENSSL_NO_GOST
629 && !((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0
630 && type == TLSEXT_TYPE_cryptopro_bug)
631#endif
632 ) {
633 SSLfatal(s, SSL_AD_UNSUPPORTED_EXTENSION,
634 SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_UNSOLICITED_EXTENSION);
635 goto err;
636 }
637 if (thisex != NULL) {
638 thisex->data = extension;
639 thisex->present = 1;
640 thisex->type = type;
641 thisex->received_order = i++;
642 if (s->ext.debug_cb)
643 s->ext.debug_cb(s, !s->server, thisex->type,
644 PACKET_data(&thisex->data),
645 PACKET_remaining(&thisex->data),
646 s->ext.debug_arg);
647 }
648 }
649
650 if (init) {
651 /*
652 * Initialise all known extensions relevant to this context,
653 * whether we have found them or not
654 */
655 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs);
656 i++, thisexd++) {
657 if (thisexd->init != NULL && (thisexd->context & context) != 0
658 && extension_is_relevant(s, thisexd->context, context)
659 && !thisexd->init(s, context)) {
660 /* SSLfatal() already called */
661 goto err;
662 }
663 }
664 }
665
666 *res = raw_extensions;
667 if (len != NULL)
668 *len = num_exts;
669 return 1;
670
671 err:
672 OPENSSL_free(raw_extensions);
673 return 0;
674}
675
676/*
677 * Runs the parser for a given extension with index |idx|. |exts| contains the
678 * list of all parsed extensions previously collected by
679 * tls_collect_extensions(). The parser is only run if it is applicable for the
680 * given |context| and the parser has not already been run. If this is for a
681 * Certificate message, then we also provide the parser with the relevant
682 * Certificate |x| and its position in the |chainidx| with 0 being the first
683 * Certificate. Returns 1 on success or 0 on failure. If an extension is not
684 * present this counted as success.
685 */
686int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
687 RAW_EXTENSION *exts, X509 *x, size_t chainidx)
688{
689 RAW_EXTENSION *currext = &exts[idx];
690 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
691 size_t chainidx) = NULL;
692
693 /* Skip if the extension is not present */
694 if (!currext->present)
695 return 1;
696
697 /* Skip if we've already parsed this extension */
698 if (currext->parsed)
699 return 1;
700
701 currext->parsed = 1;
702
703 if (idx < OSSL_NELEM(ext_defs)) {
704 /* We are handling a built-in extension */
705 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
706
707 /* Check if extension is defined for our protocol. If not, skip */
708 if (!extension_is_relevant(s, extdef->context, context))
709 return 1;
710
711 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
712
713 if (parser != NULL)
714 return parser(s, &currext->data, context, x, chainidx);
715
716 /*
717 * If the parser is NULL we fall through to the custom extension
718 * processing
719 */
720 }
721
722 /* Parse custom extensions */
723 return custom_ext_parse(s, context, currext->type,
724 PACKET_data(&currext->data),
725 PACKET_remaining(&currext->data),
726 x, chainidx);
727}
728
729/*
730 * Parse all remaining extensions that have not yet been parsed. Also calls the
731 * finalisation for all extensions at the end if |fin| is nonzero, whether we
732 * collected them or not. Returns 1 for success or 0 for failure. If we are
733 * working on a Certificate message then we also pass the Certificate |x| and
734 * its position in the |chainidx|, with 0 being the first certificate.
735 */
736int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
737 size_t chainidx, int fin)
738{
739 size_t i, numexts = OSSL_NELEM(ext_defs);
740 const EXTENSION_DEFINITION *thisexd;
741
742 /* Calculate the number of extensions in the extensions list */
743 numexts += s->cert->custext.meths_count;
744
745 /* Parse each extension in turn */
746 for (i = 0; i < numexts; i++) {
747 if (!tls_parse_extension(s, i, context, exts, x, chainidx)) {
748 /* SSLfatal() already called */
749 return 0;
750 }
751 }
752
753 if (fin) {
754 /*
755 * Finalise all known extensions relevant to this context,
756 * whether we have found them or not
757 */
758 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs);
759 i++, thisexd++) {
760 if (thisexd->final != NULL && (thisexd->context & context) != 0
761 && !thisexd->final(s, context, exts[i].present)) {
762 /* SSLfatal() already called */
763 return 0;
764 }
765 }
766 }
767
768 return 1;
769}
770
771int should_add_extension(SSL *s, unsigned int extctx, unsigned int thisctx,
772 int max_version)
773{
774 /* Skip if not relevant for our context */
775 if ((extctx & thisctx) == 0)
776 return 0;
777
778 /* Check if this extension is defined for our protocol. If not, skip */
779 if (!extension_is_relevant(s, extctx, thisctx)
780 || ((extctx & SSL_EXT_TLS1_3_ONLY) != 0
781 && (thisctx & SSL_EXT_CLIENT_HELLO) != 0
782 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION)))
783 return 0;
784
785 return 1;
786}
787
788/*
789 * Construct all the extensions relevant to the current |context| and write
790 * them to |pkt|. If this is an extension for a Certificate in a Certificate
791 * message, then |x| will be set to the Certificate we are handling, and
792 * |chainidx| will indicate the position in the chainidx we are processing (with
793 * 0 being the first in the chain). Returns 1 on success or 0 on failure. On a
794 * failure construction stops at the first extension to fail to construct.
795 */
796int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
797 X509 *x, size_t chainidx)
798{
799 size_t i;
800 int min_version, max_version = 0, reason;
801 const EXTENSION_DEFINITION *thisexd;
802
803 if (!WPACKET_start_sub_packet_u16(pkt)
804 /*
805 * If extensions are of zero length then we don't even add the
806 * extensions length bytes to a ClientHello/ServerHello
807 * (for non-TLSv1.3).
808 */
809 || ((context &
810 (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0
811 && !WPACKET_set_flags(pkt,
812 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
813 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS,
814 ERR_R_INTERNAL_ERROR);
815 return 0;
816 }
817
818 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
819 reason = ssl_get_min_max_version(s, &min_version, &max_version, NULL);
820 if (reason != 0) {
821 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS,
822 reason);
823 return 0;
824 }
825 }
826
827 /* Add custom extensions first */
828 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
829 /* On the server side with initialise during ClientHello parsing */
830 custom_ext_init(&s->cert->custext);
831 }
832 if (!custom_ext_add(s, context, pkt, x, chainidx, max_version)) {
833 /* SSLfatal() already called */
834 return 0;
835 }
836
837 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
838 EXT_RETURN (*construct)(SSL *s, WPACKET *pkt, unsigned int context,
839 X509 *x, size_t chainidx);
840 EXT_RETURN ret;
841
842 /* Skip if not relevant for our context */
843 if (!should_add_extension(s, thisexd->context, context, max_version))
844 continue;
845
846 construct = s->server ? thisexd->construct_stoc
847 : thisexd->construct_ctos;
848
849 if (construct == NULL)
850 continue;
851
852 ret = construct(s, pkt, context, x, chainidx);
853 if (ret == EXT_RETURN_FAIL) {
854 /* SSLfatal() already called */
855 return 0;
856 }
857 if (ret == EXT_RETURN_SENT
858 && (context & (SSL_EXT_CLIENT_HELLO
859 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
860 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) != 0)
861 s->ext.extflags[i] |= SSL_EXT_FLAG_SENT;
862 }
863
864 if (!WPACKET_close(pkt)) {
865 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS,
866 ERR_R_INTERNAL_ERROR);
867 return 0;
868 }
869
870 return 1;
871}
872
873/*
874 * Built in extension finalisation and initialisation functions. All initialise
875 * or finalise the associated extension type for the given |context|. For
876 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
877 * otherwise. These functions return 1 on success or 0 on failure.
878 */
879
880static int final_renegotiate(SSL *s, unsigned int context, int sent)
881{
882 if (!s->server) {
883 /*
884 * Check if we can connect to a server that doesn't support safe
885 * renegotiation
886 */
887 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
888 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
889 && !sent) {
890 SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_RENEGOTIATE,
891 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
892 return 0;
893 }
894
895 return 1;
896 }
897
898 /* Need RI if renegotiating */
899 if (s->renegotiate
900 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
901 && !sent) {
902 SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_RENEGOTIATE,
903 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
904 return 0;
905 }
906
907
908 return 1;
909}
910
911static int init_server_name(SSL *s, unsigned int context)
912{
913 if (s->server) {
914 s->servername_done = 0;
915
916 OPENSSL_free(s->ext.hostname);
917 s->ext.hostname = NULL;
918 }
919
920 return 1;
921}
922
923static int final_server_name(SSL *s, unsigned int context, int sent)
924{
925 int ret = SSL_TLSEXT_ERR_NOACK;
926 int altmp = SSL_AD_UNRECOGNIZED_NAME;
927 int was_ticket = (SSL_get_options(s) & SSL_OP_NO_TICKET) == 0;
928
929 if (!ossl_assert(s->ctx != NULL) || !ossl_assert(s->session_ctx != NULL)) {
930 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME,
931 ERR_R_INTERNAL_ERROR);
932 return 0;
933 }
934
935 if (s->ctx->ext.servername_cb != NULL)
936 ret = s->ctx->ext.servername_cb(s, &altmp,
937 s->ctx->ext.servername_arg);
938 else if (s->session_ctx->ext.servername_cb != NULL)
939 ret = s->session_ctx->ext.servername_cb(s, &altmp,
940 s->session_ctx->ext.servername_arg);
941
942 /*
943 * For servers, propagate the SNI hostname from the temporary
944 * storage in the SSL to the persistent SSL_SESSION, now that we
945 * know we accepted it.
946 * Clients make this copy when parsing the server's response to
947 * the extension, which is when they find out that the negotiation
948 * was successful.
949 */
950 if (s->server) {
951 /* TODO(OpenSSL1.2) revisit !sent case */
952 if (sent && ret == SSL_TLSEXT_ERR_OK && !s->hit) {
953 /* Only store the hostname in the session if we accepted it. */
954 OPENSSL_free(s->session->ext.hostname);
955 s->session->ext.hostname = OPENSSL_strdup(s->ext.hostname);
956 if (s->session->ext.hostname == NULL && s->ext.hostname != NULL) {
957 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME,
958 ERR_R_INTERNAL_ERROR);
959 }
960 }
961 }
962
963 /*
964 * If we switched contexts (whether here or in the client_hello callback),
965 * move the sess_accept increment from the session_ctx to the new
966 * context, to avoid the confusing situation of having sess_accept_good
967 * exceed sess_accept (zero) for the new context.
968 */
969 if (SSL_IS_FIRST_HANDSHAKE(s) && s->ctx != s->session_ctx) {
970 tsan_counter(&s->ctx->stats.sess_accept);
971 tsan_decr(&s->session_ctx->stats.sess_accept);
972 }
973
974 /*
975 * If we're expecting to send a ticket, and tickets were previously enabled,
976 * and now tickets are disabled, then turn off expected ticket.
977 * Also, if this is not a resumption, create a new session ID
978 */
979 if (ret == SSL_TLSEXT_ERR_OK && s->ext.ticket_expected
980 && was_ticket && (SSL_get_options(s) & SSL_OP_NO_TICKET) != 0) {
981 s->ext.ticket_expected = 0;
982 if (!s->hit) {
983 SSL_SESSION* ss = SSL_get_session(s);
984
985 if (ss != NULL) {
986 OPENSSL_free(ss->ext.tick);
987 ss->ext.tick = NULL;
988 ss->ext.ticklen = 0;
989 ss->ext.tick_lifetime_hint = 0;
990 ss->ext.tick_age_add = 0;
991 if (!ssl_generate_session_id(s, ss)) {
992 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME,
993 ERR_R_INTERNAL_ERROR);
994 return 0;
995 }
996 } else {
997 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME,
998 ERR_R_INTERNAL_ERROR);
999 return 0;
1000 }
1001 }
1002 }
1003
1004 switch (ret) {
1005 case SSL_TLSEXT_ERR_ALERT_FATAL:
1006 SSLfatal(s, altmp, SSL_F_FINAL_SERVER_NAME, SSL_R_CALLBACK_FAILED);
1007 return 0;
1008
1009 case SSL_TLSEXT_ERR_ALERT_WARNING:
1010 /* TLSv1.3 doesn't have warning alerts so we suppress this */
1011 if (!SSL_IS_TLS13(s))
1012 ssl3_send_alert(s, SSL3_AL_WARNING, altmp);
1013 return 1;
1014
1015 case SSL_TLSEXT_ERR_NOACK:
1016 s->servername_done = 0;
1017 return 1;
1018
1019 default:
1020 return 1;
1021 }
1022}
1023
1024#ifndef OPENSSL_NO_EC
1025static int final_ec_pt_formats(SSL *s, unsigned int context, int sent)
1026{
1027 unsigned long alg_k, alg_a;
1028
1029 if (s->server)
1030 return 1;
1031
1032 alg_k = s->s3.tmp.new_cipher->algorithm_mkey;
1033 alg_a = s->s3.tmp.new_cipher->algorithm_auth;
1034
1035 /*
1036 * If we are client and using an elliptic curve cryptography cipher
1037 * suite, then if server returns an EC point formats lists extension it
1038 * must contain uncompressed.
1039 */
1040 if (s->ext.ecpointformats != NULL
1041 && s->ext.ecpointformats_len > 0
1042 && s->ext.peer_ecpointformats != NULL
1043 && s->ext.peer_ecpointformats_len > 0
1044 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
1045 /* we are using an ECC cipher */
1046 size_t i;
1047 unsigned char *list = s->ext.peer_ecpointformats;
1048
1049 for (i = 0; i < s->ext.peer_ecpointformats_len; i++) {
1050 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
1051 break;
1052 }
1053 if (i == s->ext.peer_ecpointformats_len) {
1054 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_FINAL_EC_PT_FORMATS,
1055 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
1056 return 0;
1057 }
1058 }
1059
1060 return 1;
1061}
1062#endif
1063
1064static int init_session_ticket(SSL *s, unsigned int context)
1065{
1066 if (!s->server)
1067 s->ext.ticket_expected = 0;
1068
1069 return 1;
1070}
1071
1072#ifndef OPENSSL_NO_OCSP
1073static int init_status_request(SSL *s, unsigned int context)
1074{
1075 if (s->server) {
1076 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
1077 } else {
1078 /*
1079 * Ensure we get sensible values passed to tlsext_status_cb in the event
1080 * that we don't receive a status message
1081 */
1082 OPENSSL_free(s->ext.ocsp.resp);
1083 s->ext.ocsp.resp = NULL;
1084 s->ext.ocsp.resp_len = 0;
1085 }
1086
1087 return 1;
1088}
1089#endif
1090
1091#ifndef OPENSSL_NO_NEXTPROTONEG
1092static int init_npn(SSL *s, unsigned int context)
1093{
1094 s->s3.npn_seen = 0;
1095
1096 return 1;
1097}
1098#endif
1099
1100static int init_alpn(SSL *s, unsigned int context)
1101{
1102 OPENSSL_free(s->s3.alpn_selected);
1103 s->s3.alpn_selected = NULL;
1104 s->s3.alpn_selected_len = 0;
1105 if (s->server) {
1106 OPENSSL_free(s->s3.alpn_proposed);
1107 s->s3.alpn_proposed = NULL;
1108 s->s3.alpn_proposed_len = 0;
1109 }
1110 return 1;
1111}
1112
1113static int final_alpn(SSL *s, unsigned int context, int sent)
1114{
1115 if (!s->server && !sent && s->session->ext.alpn_selected != NULL)
1116 s->ext.early_data_ok = 0;
1117
1118 if (!s->server || !SSL_IS_TLS13(s))
1119 return 1;
1120
1121 /*
1122 * Call alpn_select callback if needed. Has to be done after SNI and
1123 * cipher negotiation (HTTP/2 restricts permitted ciphers). In TLSv1.3
1124 * we also have to do this before we decide whether to accept early_data.
1125 * In TLSv1.3 we've already negotiated our cipher so we do this call now.
1126 * For < TLSv1.3 we defer it until after cipher negotiation.
1127 *
1128 * On failure SSLfatal() already called.
1129 */
1130 return tls_handle_alpn(s);
1131}
1132
1133static int init_sig_algs(SSL *s, unsigned int context)
1134{
1135 /* Clear any signature algorithms extension received */
1136 OPENSSL_free(s->s3.tmp.peer_sigalgs);
1137 s->s3.tmp.peer_sigalgs = NULL;
1138
1139 return 1;
1140}
1141
1142static int init_sig_algs_cert(SSL *s, unsigned int context)
1143{
1144 /* Clear any signature algorithms extension received */
1145 OPENSSL_free(s->s3.tmp.peer_cert_sigalgs);
1146 s->s3.tmp.peer_cert_sigalgs = NULL;
1147
1148 return 1;
1149}
1150
1151#ifndef OPENSSL_NO_SRP
1152static int init_srp(SSL *s, unsigned int context)
1153{
1154 OPENSSL_free(s->srp_ctx.login);
1155 s->srp_ctx.login = NULL;
1156
1157 return 1;
1158}
1159#endif
1160
1161static int init_etm(SSL *s, unsigned int context)
1162{
1163 s->ext.use_etm = 0;
1164
1165 return 1;
1166}
1167
1168static int init_ems(SSL *s, unsigned int context)
1169{
1170 s->s3.flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
1171
1172 return 1;
1173}
1174
1175static int final_ems(SSL *s, unsigned int context, int sent)
1176{
1177 if (!s->server && s->hit) {
1178 /*
1179 * Check extended master secret extension is consistent with
1180 * original session.
1181 */
1182 if (!(s->s3.flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
1183 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
1184 SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_EMS,
1185 SSL_R_INCONSISTENT_EXTMS);
1186 return 0;
1187 }
1188 }
1189
1190 return 1;
1191}
1192
1193static int init_certificate_authorities(SSL *s, unsigned int context)
1194{
1195 sk_X509_NAME_pop_free(s->s3.tmp.peer_ca_names, X509_NAME_free);
1196 s->s3.tmp.peer_ca_names = NULL;
1197 return 1;
1198}
1199
1200static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
1201 unsigned int context,
1202 X509 *x,
1203 size_t chainidx)
1204{
1205 const STACK_OF(X509_NAME) *ca_sk = get_ca_names(s);
1206
1207 if (ca_sk == NULL || sk_X509_NAME_num(ca_sk) == 0)
1208 return EXT_RETURN_NOT_SENT;
1209
1210 if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_certificate_authorities)
1211 || !WPACKET_start_sub_packet_u16(pkt)) {
1212 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1213 SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,
1214 ERR_R_INTERNAL_ERROR);
1215 return EXT_RETURN_FAIL;
1216 }
1217
1218 if (!construct_ca_names(s, ca_sk, pkt)) {
1219 /* SSLfatal() already called */
1220 return EXT_RETURN_FAIL;
1221 }
1222
1223 if (!WPACKET_close(pkt)) {
1224 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1225 SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,
1226 ERR_R_INTERNAL_ERROR);
1227 return EXT_RETURN_FAIL;
1228 }
1229
1230 return EXT_RETURN_SENT;
1231}
1232
1233static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
1234 unsigned int context, X509 *x,
1235 size_t chainidx)
1236{
1237 if (!parse_ca_names(s, pkt))
1238 return 0;
1239 if (PACKET_remaining(pkt) != 0) {
1240 SSLfatal(s, SSL_AD_DECODE_ERROR,
1241 SSL_F_TLS_PARSE_CERTIFICATE_AUTHORITIES, SSL_R_BAD_EXTENSION);
1242 return 0;
1243 }
1244 return 1;
1245}
1246
1247#ifndef OPENSSL_NO_SRTP
1248static int init_srtp(SSL *s, unsigned int context)
1249{
1250 if (s->server)
1251 s->srtp_profile = NULL;
1252
1253 return 1;
1254}
1255#endif
1256
1257static int final_sig_algs(SSL *s, unsigned int context, int sent)
1258{
1259 if (!sent && SSL_IS_TLS13(s) && !s->hit) {
1260 SSLfatal(s, TLS13_AD_MISSING_EXTENSION, SSL_F_FINAL_SIG_ALGS,
1261 SSL_R_MISSING_SIGALGS_EXTENSION);
1262 return 0;
1263 }
1264
1265 return 1;
1266}
1267
1268static int final_key_share(SSL *s, unsigned int context, int sent)
1269{
1270#if !defined(OPENSSL_NO_TLS1_3)
1271 if (!SSL_IS_TLS13(s))
1272 return 1;
1273
1274 /* Nothing to do for key_share in an HRR */
1275 if ((context & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0)
1276 return 1;
1277
1278 /*
1279 * If
1280 * we are a client
1281 * AND
1282 * we have no key_share
1283 * AND
1284 * (we are not resuming
1285 * OR the kex_mode doesn't allow non key_share resumes)
1286 * THEN
1287 * fail;
1288 */
1289 if (!s->server
1290 && !sent
1291 && (!s->hit
1292 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
1293 /* Nothing left we can do - just fail */
1294 SSLfatal(s, SSL_AD_MISSING_EXTENSION, SSL_F_FINAL_KEY_SHARE,
1295 SSL_R_NO_SUITABLE_KEY_SHARE);
1296 return 0;
1297 }
1298 /*
1299 * IF
1300 * we are a server
1301 * THEN
1302 * IF
1303 * we have a suitable key_share
1304 * THEN
1305 * IF
1306 * we are stateless AND we have no cookie
1307 * THEN
1308 * send a HelloRetryRequest
1309 * ELSE
1310 * IF
1311 * we didn't already send a HelloRetryRequest
1312 * AND
1313 * the client sent a key_share extension
1314 * AND
1315 * (we are not resuming
1316 * OR the kex_mode allows key_share resumes)
1317 * AND
1318 * a shared group exists
1319 * THEN
1320 * send a HelloRetryRequest
1321 * ELSE IF
1322 * we are not resuming
1323 * OR
1324 * the kex_mode doesn't allow non key_share resumes
1325 * THEN
1326 * fail
1327 * ELSE IF
1328 * we are stateless AND we have no cookie
1329 * THEN
1330 * send a HelloRetryRequest
1331 */
1332 if (s->server) {
1333 if (s->s3.peer_tmp != NULL) {
1334 /* We have a suitable key_share */
1335 if ((s->s3.flags & TLS1_FLAGS_STATELESS) != 0
1336 && !s->ext.cookieok) {
1337 if (!ossl_assert(s->hello_retry_request == SSL_HRR_NONE)) {
1338 /*
1339 * If we are stateless then we wouldn't know about any
1340 * previously sent HRR - so how can this be anything other
1341 * than 0?
1342 */
1343 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE,
1344 ERR_R_INTERNAL_ERROR);
1345 return 0;
1346 }
1347 s->hello_retry_request = SSL_HRR_PENDING;
1348 return 1;
1349 }
1350 } else {
1351 /* No suitable key_share */
1352 if (s->hello_retry_request == SSL_HRR_NONE && sent
1353 && (!s->hit
1354 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1355 != 0)) {
1356 const uint16_t *pgroups, *clntgroups;
1357 size_t num_groups, clnt_num_groups, i;
1358 unsigned int group_id = 0;
1359
1360 /* Check if a shared group exists */
1361
1362 /* Get the clients list of supported groups. */
1363 tls1_get_peer_groups(s, &clntgroups, &clnt_num_groups);
1364 tls1_get_supported_groups(s, &pgroups, &num_groups);
1365
1366 /*
1367 * Find the first group we allow that is also in client's list
1368 */
1369 for (i = 0; i < num_groups; i++) {
1370 group_id = pgroups[i];
1371
1372 if (check_in_list(s, group_id, clntgroups, clnt_num_groups,
1373 1))
1374 break;
1375 }
1376
1377 if (i < num_groups) {
1378 /* A shared group exists so send a HelloRetryRequest */
1379 s->s3.group_id = group_id;
1380 s->hello_retry_request = SSL_HRR_PENDING;
1381 return 1;
1382 }
1383 }
1384 if (!s->hit
1385 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1386 /* Nothing left we can do - just fail */
1387 SSLfatal(s, sent ? SSL_AD_HANDSHAKE_FAILURE
1388 : SSL_AD_MISSING_EXTENSION,
1389 SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1390 return 0;
1391 }
1392
1393 if ((s->s3.flags & TLS1_FLAGS_STATELESS) != 0
1394 && !s->ext.cookieok) {
1395 if (!ossl_assert(s->hello_retry_request == SSL_HRR_NONE)) {
1396 /*
1397 * If we are stateless then we wouldn't know about any
1398 * previously sent HRR - so how can this be anything other
1399 * than 0?
1400 */
1401 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE,
1402 ERR_R_INTERNAL_ERROR);
1403 return 0;
1404 }
1405 s->hello_retry_request = SSL_HRR_PENDING;
1406 return 1;
1407 }
1408 }
1409
1410 /*
1411 * We have a key_share so don't send any more HelloRetryRequest
1412 * messages
1413 */
1414 if (s->hello_retry_request == SSL_HRR_PENDING)
1415 s->hello_retry_request = SSL_HRR_COMPLETE;
1416 } else {
1417 /*
1418 * For a client side resumption with no key_share we need to generate
1419 * the handshake secret (otherwise this is done during key_share
1420 * processing).
1421 */
1422 if (!sent && !tls13_generate_handshake_secret(s, NULL, 0)) {
1423 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE,
1424 ERR_R_INTERNAL_ERROR);
1425 return 0;
1426 }
1427 }
1428#endif /* !defined(OPENSSL_NO_TLS1_3) */
1429 return 1;
1430}
1431
1432static int init_psk_kex_modes(SSL *s, unsigned int context)
1433{
1434 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1435 return 1;
1436}
1437
1438int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1439 size_t binderoffset, const unsigned char *binderin,
1440 unsigned char *binderout, SSL_SESSION *sess, int sign,
1441 int external)
1442{
1443 EVP_PKEY *mackey = NULL;
1444 EVP_MD_CTX *mctx = NULL;
1445 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1446 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1447 unsigned char *early_secret;
1448#ifdef CHARSET_EBCDIC
1449 static const unsigned char resumption_label[] = { 0x72, 0x65, 0x73, 0x20, 0x62, 0x69, 0x6E, 0x64, 0x65, 0x72, 0x00 };
1450 static const unsigned char external_label[] = { 0x65, 0x78, 0x74, 0x20, 0x62, 0x69, 0x6E, 0x64, 0x65, 0x72, 0x00 };
1451#else
1452 static const unsigned char resumption_label[] = "res binder";
1453 static const unsigned char external_label[] = "ext binder";
1454#endif
1455 const unsigned char *label;
1456 size_t bindersize, labelsize, hashsize;
1457 int hashsizei = EVP_MD_size(md);
1458 int ret = -1;
1459 int usepskfored = 0;
1460
1461 /* Ensure cast to size_t is safe */
1462 if (!ossl_assert(hashsizei >= 0)) {
1463 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1464 ERR_R_INTERNAL_ERROR);
1465 goto err;
1466 }
1467 hashsize = (size_t)hashsizei;
1468
1469 if (external
1470 && s->early_data_state == SSL_EARLY_DATA_CONNECTING
1471 && s->session->ext.max_early_data == 0
1472 && sess->ext.max_early_data > 0)
1473 usepskfored = 1;
1474
1475 if (external) {
1476 label = external_label;
1477 labelsize = sizeof(external_label) - 1;
1478 } else {
1479 label = resumption_label;
1480 labelsize = sizeof(resumption_label) - 1;
1481 }
1482
1483 /*
1484 * Generate the early_secret. On the server side we've selected a PSK to
1485 * resume with (internal or external) so we always do this. On the client
1486 * side we do this for a non-external (i.e. resumption) PSK or external PSK
1487 * that will be used for early_data so that it is in place for sending early
1488 * data. For client side external PSK not being used for early_data we
1489 * generate it but store it away for later use.
1490 */
1491 if (s->server || !external || usepskfored)
1492 early_secret = (unsigned char *)s->early_secret;
1493 else
1494 early_secret = (unsigned char *)sess->early_secret;
1495
1496 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1497 sess->master_key_length, early_secret)) {
1498 /* SSLfatal() already called */
1499 goto err;
1500 }
1501
1502 /*
1503 * Create the handshake hash for the binder key...the messages so far are
1504 * empty!
1505 */
1506 mctx = EVP_MD_CTX_new();
1507 if (mctx == NULL
1508 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1509 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1510 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1511 ERR_R_INTERNAL_ERROR);
1512 goto err;
1513 }
1514
1515 /* Generate the binder key */
1516 if (!tls13_hkdf_expand(s, md, early_secret, label, labelsize, hash,
1517 hashsize, binderkey, hashsize, 1)) {
1518 /* SSLfatal() already called */
1519 goto err;
1520 }
1521
1522 /* Generate the finished key */
1523 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1524 /* SSLfatal() already called */
1525 goto err;
1526 }
1527
1528 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1529 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1530 ERR_R_INTERNAL_ERROR);
1531 goto err;
1532 }
1533
1534 /*
1535 * Get a hash of the ClientHello up to the start of the binders. If we are
1536 * following a HelloRetryRequest then this includes the hash of the first
1537 * ClientHello and the HelloRetryRequest itself.
1538 */
1539 if (s->hello_retry_request == SSL_HRR_PENDING) {
1540 size_t hdatalen;
1541 long hdatalen_l;
1542 void *hdata;
1543
1544 hdatalen = hdatalen_l =
1545 BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
1546 if (hdatalen_l <= 0) {
1547 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1548 SSL_R_BAD_HANDSHAKE_LENGTH);
1549 goto err;
1550 }
1551
1552 /*
1553 * For servers the handshake buffer data will include the second
1554 * ClientHello - which we don't want - so we need to take that bit off.
1555 */
1556 if (s->server) {
1557 PACKET hashprefix, msg;
1558
1559 /* Find how many bytes are left after the first two messages */
1560 if (!PACKET_buf_init(&hashprefix, hdata, hdatalen)
1561 || !PACKET_forward(&hashprefix, 1)
1562 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)
1563 || !PACKET_forward(&hashprefix, 1)
1564 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)) {
1565 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1566 ERR_R_INTERNAL_ERROR);
1567 goto err;
1568 }
1569 hdatalen -= PACKET_remaining(&hashprefix);
1570 }
1571
1572 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1573 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1574 ERR_R_INTERNAL_ERROR);
1575 goto err;
1576 }
1577 }
1578
1579 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1580 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1581 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1582 ERR_R_INTERNAL_ERROR);
1583 goto err;
1584 }
1585
1586 mackey = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finishedkey,
1587 hashsize);
1588 if (mackey == NULL) {
1589 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1590 ERR_R_INTERNAL_ERROR);
1591 goto err;
1592 }
1593
1594 if (!sign)
1595 binderout = tmpbinder;
1596
1597 bindersize = hashsize;
1598 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1599 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1600 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1601 || bindersize != hashsize) {
1602 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1603 ERR_R_INTERNAL_ERROR);
1604 goto err;
1605 }
1606
1607 if (sign) {
1608 ret = 1;
1609 } else {
1610 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1611 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1612 if (!ret)
1613 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PSK_DO_BINDER,
1614 SSL_R_BINDER_DOES_NOT_VERIFY);
1615 }
1616
1617 err:
1618 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1619 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1620 EVP_PKEY_free(mackey);
1621 EVP_MD_CTX_free(mctx);
1622
1623 return ret;
1624}
1625
1626static int final_early_data(SSL *s, unsigned int context, int sent)
1627{
1628 if (!sent)
1629 return 1;
1630
1631 if (!s->server) {
1632 if (context == SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
1633 && sent
1634 && !s->ext.early_data_ok) {
1635 /*
1636 * If we get here then the server accepted our early_data but we
1637 * later realised that it shouldn't have done (e.g. inconsistent
1638 * ALPN)
1639 */
1640 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_FINAL_EARLY_DATA,
1641 SSL_R_BAD_EARLY_DATA);
1642 return 0;
1643 }
1644
1645 return 1;
1646 }
1647
1648 if (s->max_early_data == 0
1649 || !s->hit
1650 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
1651 || !s->ext.early_data_ok
1652 || s->hello_retry_request != SSL_HRR_NONE
1653 || (s->allow_early_data_cb != NULL
1654 && !s->allow_early_data_cb(s,
1655 s->allow_early_data_cb_data))) {
1656 s->ext.early_data = SSL_EARLY_DATA_REJECTED;
1657 } else {
1658 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;
1659
1660 if (!tls13_change_cipher_state(s,
1661 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) {
1662 /* SSLfatal() already called */
1663 return 0;
1664 }
1665 }
1666
1667 return 1;
1668}
1669
1670static int final_maxfragmentlen(SSL *s, unsigned int context, int sent)
1671{
1672 /*
1673 * Session resumption on server-side with MFL extension active
1674 * BUT MFL extension packet was not resent (i.e. sent == 0)
1675 */
1676 if (s->server && s->hit && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
1677 && !sent ) {
1678 SSLfatal(s, SSL_AD_MISSING_EXTENSION, SSL_F_FINAL_MAXFRAGMENTLEN,
1679 SSL_R_BAD_EXTENSION);
1680 return 0;
1681 }
1682
1683 /* Current SSL buffer is lower than requested MFL */
1684 if (s->session && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
1685 && s->max_send_fragment < GET_MAX_FRAGMENT_LENGTH(s->session))
1686 /* trigger a larger buffer reallocation */
1687 if (!ssl3_setup_buffers(s)) {
1688 /* SSLfatal() already called */
1689 return 0;
1690 }
1691
1692 return 1;
1693}
1694
1695static int init_post_handshake_auth(SSL *s, unsigned int context)
1696{
1697 s->post_handshake_auth = SSL_PHA_NONE;
1698
1699 return 1;
1700}
1701