2 * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
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
11 #include "../ssl_locl.h"
12 #include "statem_locl.h"
14 static int final_renegotiate(SSL *s, unsigned int context, int sent,
16 static int init_server_name(SSL *s, unsigned int context);
17 static int final_server_name(SSL *s, unsigned int context, int sent,
20 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
23 static int init_session_ticket(SSL *s, unsigned int context);
24 #ifndef OPENSSL_NO_OCSP
25 static int init_status_request(SSL *s, unsigned int context);
27 #ifndef OPENSSL_NO_NEXTPROTONEG
28 static int init_npn(SSL *s, unsigned int context);
30 static int init_alpn(SSL *s, unsigned int context);
31 static int final_alpn(SSL *s, unsigned int context, int sent, int *al);
32 static int init_sig_algs(SSL *s, unsigned int context);
33 #ifndef OPENSSL_NO_SRP
34 static int init_srp(SSL *s, unsigned int context);
36 static int init_etm(SSL *s, unsigned int context);
37 static int init_ems(SSL *s, unsigned int context);
38 static int final_ems(SSL *s, unsigned int context, int sent, int *al);
39 static int init_psk_kex_modes(SSL *s, unsigned int context);
41 static int final_key_share(SSL *s, unsigned int context, int sent, int *al);
43 #ifndef OPENSSL_NO_SRTP
44 static int init_srtp(SSL *s, unsigned int context);
46 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al);
47 static int final_early_data(SSL *s, unsigned int context, int sent, int *al);
49 /* Structure to define a built-in extension */
50 typedef struct extensions_definition_st {
51 /* The defined type for the extension */
54 * The context that this extension applies to, e.g. what messages and
59 * Initialise extension before parsing. Always called for relevant contexts
60 * even if extension not present
62 int (*init)(SSL *s, unsigned int context);
63 /* Parse extension sent from client to server */
64 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
65 size_t chainidx, int *al);
66 /* Parse extension send from server to client */
67 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
68 size_t chainidx, int *al);
69 /* Construct extension sent from server to client */
70 int (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
71 size_t chainidx, int *al);
72 /* Construct extension sent from client to server */
73 int (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
74 size_t chainidx, int *al);
76 * Finalise extension after parsing. Always called where an extensions was
77 * initialised even if the extension was not present. |sent| is set to 1 if
78 * the extension was seen, or 0 otherwise.
80 int (*final)(SSL *s, unsigned int context, int sent, int *al);
81 } EXTENSION_DEFINITION;
84 * Definitions of all built-in extensions. NOTE: Changes in the number or order
85 * of these extensions should be mirrored with equivalent changes to the
86 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
87 * Each extension has an initialiser, a client and
88 * server side parser and a finaliser. The initialiser is called (if the
89 * extension is relevant to the given context) even if we did not see the
90 * extension in the message that we received. The parser functions are only
91 * called if we see the extension in the message. The finalisers are always
92 * called if the initialiser was called.
93 * There are also server and client side constructor functions which are always
94 * called during message construction if the extension is relevant for the
96 * The initialisation, parsing, finalisation and construction functions are
97 * always called in the order defined in this list. Some extensions may depend
98 * on others having been processed first, so the order of this list is
100 * The extension context is defined by a series of flags which specify which
101 * messages the extension is relevant to. These flags also specify whether the
102 * extension is relevant to a particular protocol or protocol version.
104 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
106 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
107 static const EXTENSION_DEFINITION ext_defs[] = {
109 TLSEXT_TYPE_renegotiate,
110 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_SSL3_ALLOWED
111 | EXT_TLS1_2_AND_BELOW_ONLY,
112 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
113 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
117 TLSEXT_TYPE_server_name,
118 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
119 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
121 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
122 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
125 #ifndef OPENSSL_NO_SRP
128 EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
129 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
135 TLSEXT_TYPE_early_data_info,
136 EXT_TLS1_3_NEW_SESSION_TICKET,
137 NULL, NULL, tls_parse_stoc_early_data_info,
138 tls_construct_stoc_early_data_info, NULL, NULL
140 #ifndef OPENSSL_NO_EC
142 TLSEXT_TYPE_ec_point_formats,
143 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
144 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
145 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
149 TLSEXT_TYPE_supported_groups,
150 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
151 NULL, tls_parse_ctos_supported_groups, NULL,
152 NULL /* TODO(TLS1.3): Need to add this */,
153 tls_construct_ctos_supported_groups, NULL
160 TLSEXT_TYPE_session_ticket,
161 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
162 init_session_ticket, tls_parse_ctos_session_ticket,
163 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
164 tls_construct_ctos_session_ticket, NULL
167 TLSEXT_TYPE_signature_algorithms,
169 init_sig_algs, tls_parse_ctos_sig_algs, NULL, NULL,
170 tls_construct_ctos_sig_algs, final_sig_algs
172 #ifndef OPENSSL_NO_OCSP
174 TLSEXT_TYPE_status_request,
175 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
176 | EXT_TLS1_3_CERTIFICATE,
177 init_status_request, tls_parse_ctos_status_request,
178 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
179 tls_construct_ctos_status_request, NULL
184 #ifndef OPENSSL_NO_NEXTPROTONEG
186 TLSEXT_TYPE_next_proto_neg,
187 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
188 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
189 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
196 * Must appear in this list after server_name so that finalisation
197 * happens after server_name callbacks
199 TLSEXT_TYPE_application_layer_protocol_negotiation,
200 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
201 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
202 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
203 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
205 #ifndef OPENSSL_NO_SRTP
207 TLSEXT_TYPE_use_srtp,
208 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
209 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY,
210 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
211 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
217 TLSEXT_TYPE_encrypt_then_mac,
218 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY | EXT_SSL3_ALLOWED,
219 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
220 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
222 #ifndef OPENSSL_NO_CT
224 TLSEXT_TYPE_signed_certificate_timestamp,
225 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
226 | EXT_TLS1_3_CERTIFICATE,
229 * No server side support for this, but can be provided by a custom
230 * extension. This is an exception to the rule that custom extensions
231 * cannot override built in ones.
233 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
239 TLSEXT_TYPE_extended_master_secret,
240 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
241 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
242 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
245 TLSEXT_TYPE_supported_versions,
246 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
248 /* Processed inline as part of version selection */
249 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
252 TLSEXT_TYPE_psk_kex_modes,
253 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
254 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
255 tls_construct_ctos_psk_kex_modes, NULL
257 #ifndef OPENSSL_NO_EC
260 * Must be in this list after supported_groups. We need that to have
261 * been parsed before we do this one.
263 TLSEXT_TYPE_key_share,
264 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO
265 | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY
267 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
268 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
274 EXT_CLIENT_HELLO | EXT_TLS1_3_HELLO_RETRY_REQUEST
275 | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
276 NULL, NULL, tls_parse_stoc_cookie, NULL, tls_construct_ctos_cookie,
281 * Special unsolicited ServerHello extension only used when
282 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
284 TLSEXT_TYPE_cryptopro_bug,
285 EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
286 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
289 TLSEXT_TYPE_early_data,
290 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
291 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data,
292 tls_construct_stoc_early_data, tls_construct_ctos_early_data,
296 /* Must be immediately before pre_shared_key */
297 /* TODO(TLS1.3): Fix me */
301 /* We send this, but don't read it */
302 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
305 /* Required by the TLSv1.3 spec to always be the last extension */
307 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO | EXT_TLS_IMPLEMENTATION_ONLY
309 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
310 tls_construct_ctos_psk, NULL
315 * Verify whether we are allowed to use the extension |type| in the current
316 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
317 * indicate the extension is not allowed. If returning 1 then |*found| is set to
318 * 1 if we found a definition for the extension, and |*idx| is set to its index
320 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
321 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
322 RAW_EXTENSION **found)
325 size_t builtin_num = OSSL_NELEM(ext_defs);
326 const EXTENSION_DEFINITION *thisext;
328 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
329 if (type == thisext->type) {
330 /* Check we're allowed to use this extension in this context */
331 if ((context & thisext->context) == 0)
334 if (SSL_IS_DTLS(s)) {
335 if ((thisext->context & EXT_TLS_ONLY) != 0)
337 } else if ((thisext->context & EXT_DTLS_ONLY) != 0) {
341 *found = &rawexlist[i];
346 if ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) == 0) {
348 * Custom extensions only apply to <=TLS1.2. This extension is unknown
349 * in this context - we allow it
355 /* Check the custom extensions */
357 for (i = builtin_num; i < builtin_num + meths->meths_count; i++) {
358 if (meths->meths[i - builtin_num].ext_type == type) {
359 *found = &rawexlist[i];
365 /* Unknown extension. We allow it */
371 * Check whether the context defined for an extension |extctx| means whether
372 * the extension is relevant for the current context |thisctx| or not. Returns
373 * 1 if the extension is relevant for this context, and 0 otherwise
375 static int extension_is_relevant(SSL *s, unsigned int extctx,
376 unsigned int thisctx)
379 && (extctx & EXT_TLS_IMPLEMENTATION_ONLY) != 0)
380 || (s->version == SSL3_VERSION
381 && (extctx & EXT_SSL3_ALLOWED) == 0)
383 && (extctx & EXT_TLS1_2_AND_BELOW_ONLY) != 0)
384 || (!SSL_IS_TLS13(s) && (extctx & EXT_TLS1_3_ONLY) != 0))
391 * Gather a list of all the extensions from the data in |packet]. |context|
392 * tells us which message this extension is for. The raw extension data is
393 * stored in |*res| on success. In the event of an error the alert type to use
394 * is stored in |*al|. We don't actually process the content of the extensions
395 * yet, except to check their types. This function also runs the initialiser
396 * functions for all known extensions (whether we have collected them or not).
397 * If successful the caller is responsible for freeing the contents of |*res|.
399 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
400 * more than one extension of the same type in a ClientHello or ServerHello.
401 * This function returns 1 if all extensions are unique and we have parsed their
402 * types, and 0 if the extensions contain duplicates, could not be successfully
403 * found, or an internal error occurred. We only check duplicates for
404 * extensions that we know about. We ignore others.
406 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
407 RAW_EXTENSION **res, int *al, size_t *len)
409 PACKET extensions = *packet;
412 custom_ext_methods *exts = NULL;
413 RAW_EXTENSION *raw_extensions = NULL;
414 const EXTENSION_DEFINITION *thisexd;
419 * Initialise server side custom extensions. Client side is done during
420 * construction of extensions for the ClientHello.
422 if ((context & EXT_CLIENT_HELLO) != 0) {
423 exts = &s->cert->srv_ext;
424 custom_ext_init(&s->cert->srv_ext);
425 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
426 exts = &s->cert->cli_ext;
429 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
430 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
431 if (raw_extensions == NULL) {
432 *al = SSL_AD_INTERNAL_ERROR;
433 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
437 while (PACKET_remaining(&extensions) > 0) {
440 RAW_EXTENSION *thisex;
442 if (!PACKET_get_net_2(&extensions, &type) ||
443 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
444 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
445 *al = SSL_AD_DECODE_ERROR;
449 * Verify this extension is allowed. We only check duplicates for
450 * extensions that we recognise.
452 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
453 || (thisex != NULL && thisex->present == 1)) {
454 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
455 *al = SSL_AD_ILLEGAL_PARAMETER;
458 if (thisex != NULL) {
459 thisex->data = extension;
466 * Initialise all known extensions relevant to this context, whether we have
469 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
470 if(thisexd->init != NULL && (thisexd->context & context) != 0
471 && extension_is_relevant(s, thisexd->context, context)
472 && !thisexd->init(s, context)) {
473 *al = SSL_AD_INTERNAL_ERROR;
478 *res = raw_extensions;
484 OPENSSL_free(raw_extensions);
489 * Runs the parser for a given extension with index |idx|. |exts| contains the
490 * list of all parsed extensions previously collected by
491 * tls_collect_extensions(). The parser is only run if it is applicable for the
492 * given |context| and the parser has not already been run. If this is for a
493 * Certificate message, then we also provide the parser with the relevant
494 * Certificate |x| and its position in the |chainidx| with 0 being the first
495 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
496 * |*al| is populated with a suitable alert code. If an extension is not present
497 * this counted as success.
499 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
500 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
502 RAW_EXTENSION *currext = &exts[idx];
503 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
504 size_t chainidx, int *al) = NULL;
506 /* Skip if the extension is not present */
507 if (!currext->present)
511 s->ext.debug_cb(s, !s->server, currext->type,
512 PACKET_data(&currext->data),
513 PACKET_remaining(&currext->data),
516 /* Skip if we've already parsed this extension */
522 if (idx < OSSL_NELEM(ext_defs)) {
523 /* We are handling a built-in extension */
524 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
526 /* Check if extension is defined for our protocol. If not, skip */
527 if (!extension_is_relevant(s, extdef->context, context))
530 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
533 return parser(s, &currext->data, context, x, chainidx, al);
536 * If the parser is NULL we fall through to the custom extension
542 * This is a custom extension. We only allow this if it is a non
543 * resumed session on the server side.
545 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
546 * We're going to need a new mechanism for TLS1.3 to specify which
547 * messages to add the custom extensions to.
549 if ((!s->hit || !s->server)
551 & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
552 && custom_ext_parse(s, s->server, currext->type,
553 PACKET_data(&currext->data),
554 PACKET_remaining(&currext->data),
562 * Parse all remaining extensions that have not yet been parsed. Also calls the
563 * finalisation for all extensions at the end, whether we collected them or not.
564 * Returns 1 for success or 0 for failure. If we are working on a Certificate
565 * message then we also pass the Certificate |x| and its position in the
566 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
567 * populated with a suitable alert code.
569 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
570 size_t chainidx, int *al)
572 size_t i, numexts = OSSL_NELEM(ext_defs);
573 const EXTENSION_DEFINITION *thisexd;
575 /* Calculate the number of extensions in the extensions list */
576 if ((context & EXT_CLIENT_HELLO) != 0) {
577 numexts += s->cert->srv_ext.meths_count;
578 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
579 numexts += s->cert->cli_ext.meths_count;
582 /* Parse each extension in turn */
583 for (i = 0; i < numexts; i++) {
584 if (!tls_parse_extension(s, i, context, exts, x, chainidx, al))
589 * Finalise all known extensions relevant to this context, whether we have
592 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
593 if(thisexd->final != NULL
594 && (thisexd->context & context) != 0
595 && !thisexd->final(s, context, exts[i].present, al))
603 * Construct all the extensions relevant to the current |context| and write
604 * them to |pkt|. If this is an extension for a Certificate in a Certificate
605 * message, then |x| will be set to the Certificate we are handling, and
606 * |chainidx| will indicate the position in the chainidx we are processing (with
607 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
608 * failure occurs then |al| is populated with a suitable alert code. On a
609 * failure construction stops at the first extension to fail to construct.
611 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
612 X509 *x, size_t chainidx, int *al)
615 int addcustom = 0, min_version, max_version = 0, reason, tmpal;
616 const EXTENSION_DEFINITION *thisexd;
619 * Normally if something goes wrong during construction it's an internal
620 * error. We can always override this later.
622 tmpal = SSL_AD_INTERNAL_ERROR;
624 if (!WPACKET_start_sub_packet_u16(pkt)
626 * If extensions are of zero length then we don't even add the
627 * extensions length bytes to a ClientHello/ServerHello in SSLv3
629 || ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
630 && s->version == SSL3_VERSION
631 && !WPACKET_set_flags(pkt,
632 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
633 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
637 if ((context & EXT_CLIENT_HELLO) != 0) {
638 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
640 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
645 /* Add custom extensions first */
646 if ((context & EXT_CLIENT_HELLO) != 0) {
647 custom_ext_init(&s->cert->cli_ext);
649 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
651 * We already initialised the custom extensions during ClientHello
654 * TODO(TLS1.3): We're going to need a new custom extension mechanism
655 * for TLS1.3, so that custom extensions can specify which of the
656 * multiple message they wish to add themselves to.
661 if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) {
662 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
666 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
667 int (*construct)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
668 size_t chainidx, int *al);
670 /* Skip if not relevant for our context */
671 if ((thisexd->context & context) == 0)
674 construct = s->server ? thisexd->construct_stoc
675 : thisexd->construct_ctos;
677 /* Check if this extension is defined for our protocol. If not, skip */
679 && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY)
681 || (s->version == SSL3_VERSION
682 && (thisexd->context & EXT_SSL3_ALLOWED) == 0)
684 && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY)
687 && (thisexd->context & EXT_TLS1_3_ONLY) != 0
688 && (context & EXT_CLIENT_HELLO) == 0)
689 || ((thisexd->context & EXT_TLS1_3_ONLY) != 0
690 && (context & EXT_CLIENT_HELLO) != 0
691 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))
692 || construct == NULL)
695 if (!construct(s, pkt, context, x, chainidx, &tmpal))
699 if (!WPACKET_close(pkt)) {
700 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
712 * Built in extension finalisation and initialisation functions. All initialise
713 * or finalise the associated extension type for the given |context|. For
714 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
715 * otherwise. These functions return 1 on success or 0 on failure. In the event
716 * of a failure then |*al| is populated with a suitable error code.
719 static int final_renegotiate(SSL *s, unsigned int context, int sent,
724 * Check if we can connect to a server that doesn't support safe
727 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
728 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
730 *al = SSL_AD_HANDSHAKE_FAILURE;
731 SSLerr(SSL_F_FINAL_RENEGOTIATE,
732 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
739 /* Need RI if renegotiating */
741 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
743 *al = SSL_AD_HANDSHAKE_FAILURE;
744 SSLerr(SSL_F_FINAL_RENEGOTIATE,
745 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
753 static int init_server_name(SSL *s, unsigned int context)
756 s->servername_done = 0;
761 static int final_server_name(SSL *s, unsigned int context, int sent,
764 int ret = SSL_TLSEXT_ERR_NOACK;
765 int altmp = SSL_AD_UNRECOGNIZED_NAME;
767 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
768 ret = s->ctx->ext.servername_cb(s, &altmp,
769 s->ctx->ext.servername_arg);
770 else if (s->session_ctx != NULL
771 && s->session_ctx->ext.servername_cb != 0)
772 ret = s->session_ctx->ext.servername_cb(s, &altmp,
773 s->session_ctx->ext.servername_arg);
776 case SSL_TLSEXT_ERR_ALERT_FATAL:
780 case SSL_TLSEXT_ERR_ALERT_WARNING:
784 case SSL_TLSEXT_ERR_NOACK:
785 s->servername_done = 0;
793 #ifndef OPENSSL_NO_EC
794 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
797 unsigned long alg_k, alg_a;
802 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
803 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
806 * If we are client and using an elliptic curve cryptography cipher
807 * suite, then if server returns an EC point formats lists extension it
808 * must contain uncompressed.
810 if (s->ext.ecpointformats != NULL
811 && s->ext.ecpointformats_len > 0
812 && s->session->ext.ecpointformats != NULL
813 && s->session->ext.ecpointformats_len > 0
814 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
815 /* we are using an ECC cipher */
817 unsigned char *list = s->session->ext.ecpointformats;
819 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
820 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
823 if (i == s->session->ext.ecpointformats_len) {
824 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
825 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
834 static int init_session_ticket(SSL *s, unsigned int context)
837 s->ext.ticket_expected = 0;
842 #ifndef OPENSSL_NO_OCSP
843 static int init_status_request(SSL *s, unsigned int context)
846 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
849 * Ensure we get sensible values passed to tlsext_status_cb in the event
850 * that we don't receive a status message
852 OPENSSL_free(s->ext.ocsp.resp);
853 s->ext.ocsp.resp = NULL;
854 s->ext.ocsp.resp_len = 0;
861 #ifndef OPENSSL_NO_NEXTPROTONEG
862 static int init_npn(SSL *s, unsigned int context)
870 static int init_alpn(SSL *s, unsigned int context)
872 OPENSSL_free(s->s3->alpn_selected);
873 s->s3->alpn_selected = NULL;
875 s->s3->alpn_selected_len = 0;
876 OPENSSL_free(s->s3->alpn_proposed);
877 s->s3->alpn_proposed = NULL;
878 s->s3->alpn_proposed_len = 0;
883 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
885 const unsigned char *selected = NULL;
886 unsigned char selected_len = 0;
891 if (s->ctx->ext.alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
892 int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len,
893 s->s3->alpn_proposed,
894 (unsigned int)s->s3->alpn_proposed_len,
895 s->ctx->ext.alpn_select_cb_arg);
897 if (r == SSL_TLSEXT_ERR_OK) {
898 OPENSSL_free(s->s3->alpn_selected);
899 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
900 if (s->s3->alpn_selected == NULL) {
901 *al = SSL_AD_INTERNAL_ERROR;
904 s->s3->alpn_selected_len = selected_len;
905 #ifndef OPENSSL_NO_NEXTPROTONEG
906 /* ALPN takes precedence over NPN. */
910 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
918 static int init_sig_algs(SSL *s, unsigned int context)
920 /* Clear any signature algorithms extension received */
921 OPENSSL_free(s->s3->tmp.peer_sigalgs);
922 s->s3->tmp.peer_sigalgs = NULL;
927 #ifndef OPENSSL_NO_SRP
928 static int init_srp(SSL *s, unsigned int context)
930 OPENSSL_free(s->srp_ctx.login);
931 s->srp_ctx.login = NULL;
937 static int init_etm(SSL *s, unsigned int context)
944 static int init_ems(SSL *s, unsigned int context)
947 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
952 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
954 if (!s->server && s->hit) {
956 * Check extended master secret extension is consistent with
959 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
960 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
961 *al = SSL_AD_HANDSHAKE_FAILURE;
962 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
970 #ifndef OPENSSL_NO_SRTP
971 static int init_srtp(SSL *s, unsigned int context)
974 s->srtp_profile = NULL;
980 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
982 if (!sent && SSL_IS_TLS13(s)) {
983 *al = TLS13_AD_MISSING_EXTENSION;
984 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
991 #ifndef OPENSSL_NO_EC
992 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
994 if (!SSL_IS_TLS13(s))
1001 * we have no key_share
1003 * (we are not resuming
1004 * OR the kex_mode doesn't allow non key_share resumes)
1011 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
1012 /* Nothing left we can do - just fail */
1013 *al = SSL_AD_HANDSHAKE_FAILURE;
1014 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1021 * we have no key_share
1024 * we didn't already send a HelloRetryRequest
1026 * the client sent a key_share extension
1028 * (we are not resuming
1029 * OR the kex_mode allows key_share resumes)
1031 * a shared group exists
1033 * send a HelloRetryRequest
1035 * we are not resuming
1037 * the kex_mode doesn't allow non key_share resumes
1041 if (s->server && s->s3->peer_tmp == NULL) {
1042 /* No suitable share */
1043 if (s->hello_retry_request == 0 && sent
1045 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1047 const unsigned char *pcurves, *pcurvestmp, *clntcurves;
1048 size_t num_curves, clnt_num_curves, i;
1049 unsigned int group_id = 0;
1051 /* Check if a shared group exists */
1053 /* Get the clients list of supported groups. */
1054 if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
1055 *al = SSL_AD_INTERNAL_ERROR;
1056 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1060 /* Get our list of available groups */
1061 if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
1062 *al = SSL_AD_INTERNAL_ERROR;
1063 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1067 /* Find the first group we allow that is also in client's list */
1068 for (i = 0, pcurvestmp = pcurves; i < num_curves;
1069 i++, pcurvestmp += 2) {
1070 group_id = bytestogroup(pcurvestmp);
1072 if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1))
1076 if (i < num_curves) {
1077 /* A shared group exists so send a HelloRetryRequest */
1078 s->s3->group_id = group_id;
1079 s->hello_retry_request = 1;
1084 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1085 /* Nothing left we can do - just fail */
1086 *al = SSL_AD_HANDSHAKE_FAILURE;
1087 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1092 /* We have a key_share so don't send any more HelloRetryRequest messages */
1094 s->hello_retry_request = 0;
1097 * For a client side resumption with no key_share we need to generate
1098 * the handshake secret (otherwise this is done during key_share
1101 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
1102 *al = SSL_AD_INTERNAL_ERROR;
1103 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1111 static int init_psk_kex_modes(SSL *s, unsigned int context)
1113 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1117 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1118 size_t binderoffset, const unsigned char *binderin,
1119 unsigned char *binderout,
1120 SSL_SESSION *sess, int sign)
1122 EVP_PKEY *mackey = NULL;
1123 EVP_MD_CTX *mctx = NULL;
1124 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1125 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1126 const char resumption_label[] = "resumption psk binder key";
1127 size_t bindersize, hashsize = EVP_MD_size(md);
1130 /* Generate the early_secret */
1131 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1132 sess->master_key_length,
1133 (unsigned char *)&s->early_secret)) {
1134 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1139 * Create the handshake hash for the binder key...the messages so far are
1142 mctx = EVP_MD_CTX_new();
1144 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1145 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1146 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1150 /* Generate the binder key */
1151 if (!tls13_hkdf_expand(s, md, s->early_secret,
1152 (unsigned char *)resumption_label,
1153 sizeof(resumption_label) - 1, hash, binderkey,
1155 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1159 /* Generate the finished key */
1160 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1161 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1165 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1166 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1171 * Get a hash of the ClientHello up to the start of the binders. If we are
1172 * following a HelloRetryRequest then this includes the hash of the first
1173 * ClientHello and the HelloRetryRequest itself.
1175 if (s->hello_retry_request) {
1179 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
1180 if (hdatalen <= 0) {
1181 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_HANDSHAKE_LENGTH);
1186 * For servers the handshake buffer data will include the second
1187 * ClientHello - which we don't want - so we need to take that bit off.
1190 if (hdatalen < s->init_num + SSL3_HM_HEADER_LENGTH) {
1191 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1194 hdatalen -= s->init_num + SSL3_HM_HEADER_LENGTH;
1197 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1198 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1203 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1204 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1205 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1209 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1210 if (mackey == NULL) {
1211 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1216 binderout = tmpbinder;
1218 bindersize = hashsize;
1219 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1220 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1221 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1222 || bindersize != hashsize) {
1223 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1230 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1231 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1235 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1236 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1237 EVP_PKEY_free(mackey);
1238 EVP_MD_CTX_free(mctx);
1243 static int final_early_data(SSL *s, unsigned int context, int sent, int *al)
1245 if (!s->server || !sent)
1248 if (s->max_early_data == 0
1250 || s->session->ext.tick_identity != 0
1251 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
1252 || !s->ext.early_data_ok
1253 || s->hello_retry_request
1254 || s->s3->alpn_selected_len != s->session->ext.alpn_selected_len
1255 || memcmp(s->s3->alpn_selected, s->session->ext.alpn_selected,
1256 s->s3->alpn_selected_len) != 0){
1257 s->ext.early_data = SSL_EARLY_DATA_REJECTED;
1259 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;
1261 if (!tls13_change_cipher_state(s,
1262 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) {
1263 *al = SSL_AD_INTERNAL_ERROR;