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
10 #include "../ssl_locl.h"
11 #include "statem_locl.h"
13 static int final_renegotiate(SSL *s, unsigned int context, int sent,
15 static int init_server_name(SSL *s, unsigned int context);
16 static int final_server_name(SSL *s, unsigned int context, int sent,
19 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
22 static int init_session_ticket(SSL *s, unsigned int context);
23 #ifndef OPENSSL_NO_OCSP
24 static int init_status_request(SSL *s, unsigned int context);
26 #ifndef OPENSSL_NO_NEXTPROTONEG
27 static int init_npn(SSL *s, unsigned int context);
29 static int init_alpn(SSL *s, unsigned int context);
30 static int final_alpn(SSL *s, unsigned int context, int sent, int *al);
31 static int init_sig_algs(SSL *s, unsigned int context);
32 #ifndef OPENSSL_NO_SRP
33 static int init_srp(SSL *s, unsigned int context);
35 static int init_etm(SSL *s, unsigned int context);
36 static int init_ems(SSL *s, unsigned int context);
37 static int final_ems(SSL *s, unsigned int context, int sent, int *al);
38 static int init_psk_kex_modes(SSL *s, unsigned int context);
40 static int final_key_share(SSL *s, unsigned int context, int sent, int *al);
42 #ifndef OPENSSL_NO_SRTP
43 static int init_srtp(SSL *s, unsigned int context);
45 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al);
47 /* Structure to define a built-in extension */
48 typedef struct extensions_definition_st {
49 /* The defined type for the extension */
52 * The context that this extension applies to, e.g. what messages and
57 * Initialise extension before parsing. Always called for relevant contexts
58 * even if extension not present
60 int (*init)(SSL *s, unsigned int context);
61 /* Parse extension sent from client to server */
62 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
63 size_t chainidx, int *al);
64 /* Parse extension send from server to client */
65 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
66 size_t chainidx, int *al);
67 /* Construct extension sent from server to client */
68 int (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
69 size_t chainidx, int *al);
70 /* Construct extension sent from client to server */
71 int (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
72 size_t chainidx, int *al);
74 * Finalise extension after parsing. Always called where an extensions was
75 * initialised even if the extension was not present. |sent| is set to 1 if
76 * the extension was seen, or 0 otherwise.
78 int (*final)(SSL *s, unsigned int context, int sent, int *al);
79 } EXTENSION_DEFINITION;
82 * Definitions of all built-in extensions. NOTE: Changes in the number or order
83 * of these extensions should be mirrored with equivalent changes to the
84 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
85 * Each extension has an initialiser, a client and
86 * server side parser and a finaliser. The initialiser is called (if the
87 * extension is relevant to the given context) even if we did not see the
88 * extension in the message that we received. The parser functions are only
89 * called if we see the extension in the message. The finalisers are always
90 * called if the initialiser was called.
91 * There are also server and client side constructor functions which are always
92 * called during message construction if the extension is relevant for the
94 * The initialisation, parsing, finalisation and construction functions are
95 * always called in the order defined in this list. Some extensions may depend
96 * on others having been processed first, so the order of this list is
98 * The extension context is defined by a series of flags which specify which
99 * messages the extension is relevant to. These flags also specify whether the
100 * extension is relevant to a particular protocol or protocol version.
102 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
104 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
105 static const EXTENSION_DEFINITION ext_defs[] = {
107 TLSEXT_TYPE_renegotiate,
108 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_SSL3_ALLOWED
109 | EXT_TLS1_2_AND_BELOW_ONLY,
110 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
111 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
115 TLSEXT_TYPE_server_name,
116 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
117 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
119 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
120 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
123 #ifndef OPENSSL_NO_SRP
126 EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
127 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
133 TLSEXT_TYPE_early_data_info,
134 EXT_TLS1_3_NEW_SESSION_TICKET,
135 NULL, NULL, NULL, tls_construct_stoc_early_data_info, NULL, NULL
137 #ifndef OPENSSL_NO_EC
139 TLSEXT_TYPE_ec_point_formats,
140 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
141 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
142 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
146 TLSEXT_TYPE_supported_groups,
147 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
148 NULL, tls_parse_ctos_supported_groups, NULL,
149 NULL /* TODO(TLS1.3): Need to add this */,
150 tls_construct_ctos_supported_groups, NULL
157 TLSEXT_TYPE_session_ticket,
158 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
159 init_session_ticket, tls_parse_ctos_session_ticket,
160 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
161 tls_construct_ctos_session_ticket, NULL
164 TLSEXT_TYPE_signature_algorithms,
166 init_sig_algs, tls_parse_ctos_sig_algs, NULL, NULL,
167 tls_construct_ctos_sig_algs, final_sig_algs
169 #ifndef OPENSSL_NO_OCSP
171 TLSEXT_TYPE_status_request,
172 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
173 | EXT_TLS1_3_CERTIFICATE,
174 init_status_request, tls_parse_ctos_status_request,
175 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
176 tls_construct_ctos_status_request, NULL
181 #ifndef OPENSSL_NO_NEXTPROTONEG
183 TLSEXT_TYPE_next_proto_neg,
184 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
185 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
186 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
193 * Must appear in this list after server_name so that finalisation
194 * happens after server_name callbacks
196 TLSEXT_TYPE_application_layer_protocol_negotiation,
197 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
198 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
199 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
200 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
202 #ifndef OPENSSL_NO_SRTP
204 TLSEXT_TYPE_use_srtp,
205 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
206 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY,
207 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
208 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
214 TLSEXT_TYPE_encrypt_then_mac,
215 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY | EXT_SSL3_ALLOWED,
216 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
217 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
219 #ifndef OPENSSL_NO_CT
221 TLSEXT_TYPE_signed_certificate_timestamp,
222 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
223 | EXT_TLS1_3_CERTIFICATE,
226 * No server side support for this, but can be provided by a custom
227 * extension. This is an exception to the rule that custom extensions
228 * cannot override built in ones.
230 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
236 TLSEXT_TYPE_extended_master_secret,
237 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
238 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
239 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
242 TLSEXT_TYPE_supported_versions,
243 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
245 /* Processed inline as part of version selection */
246 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
249 TLSEXT_TYPE_psk_kex_modes,
250 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
251 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
252 tls_construct_ctos_psk_kex_modes, NULL
254 #ifndef OPENSSL_NO_EC
257 * Must be in this list after supported_groups. We need that to have
258 * been parsed before we do this one.
260 TLSEXT_TYPE_key_share,
261 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO
262 | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY
264 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
265 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
271 * Special unsolicited ServerHello extension only used when
272 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
274 TLSEXT_TYPE_cryptopro_bug,
275 EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
276 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
279 /* Must be immediately before pre_shared_key */
280 /* TODO(TLS1.3): Fix me */
284 /* We send this, but don't read it */
285 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
288 /* Required by the TLSv1.3 spec to always be the last extension */
290 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO | EXT_TLS_IMPLEMENTATION_ONLY
292 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
293 tls_construct_ctos_psk, NULL
298 * Verify whether we are allowed to use the extension |type| in the current
299 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
300 * indicate the extension is not allowed. If returning 1 then |*found| is set to
301 * 1 if we found a definition for the extension, and |*idx| is set to its index
303 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
304 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
305 RAW_EXTENSION **found)
308 size_t builtin_num = OSSL_NELEM(ext_defs);
309 const EXTENSION_DEFINITION *thisext;
311 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
312 if (type == thisext->type) {
313 /* Check we're allowed to use this extension in this context */
314 if ((context & thisext->context) == 0)
317 if (SSL_IS_DTLS(s)) {
318 if ((thisext->context & EXT_TLS_ONLY) != 0)
320 } else if ((thisext->context & EXT_DTLS_ONLY) != 0) {
324 *found = &rawexlist[i];
329 if ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) == 0) {
331 * Custom extensions only apply to <=TLS1.2. This extension is unknown
332 * in this context - we allow it
338 /* Check the custom extensions */
340 for (i = builtin_num; i < builtin_num + meths->meths_count; i++) {
341 if (meths->meths[i - builtin_num].ext_type == type) {
342 *found = &rawexlist[i];
348 /* Unknown extension. We allow it */
354 * Check whether the context defined for an extension |extctx| means whether
355 * the extension is relevant for the current context |thisctx| or not. Returns
356 * 1 if the extension is relevant for this context, and 0 otherwise
358 static int extension_is_relevant(SSL *s, unsigned int extctx,
359 unsigned int thisctx)
362 && (extctx & EXT_TLS_IMPLEMENTATION_ONLY) != 0)
363 || (s->version == SSL3_VERSION
364 && (extctx & EXT_SSL3_ALLOWED) == 0)
366 && (extctx & EXT_TLS1_2_AND_BELOW_ONLY) != 0)
367 || (!SSL_IS_TLS13(s) && (extctx & EXT_TLS1_3_ONLY) != 0))
374 * Gather a list of all the extensions from the data in |packet]. |context|
375 * tells us which message this extension is for. The raw extension data is
376 * stored in |*res| on success. In the event of an error the alert type to use
377 * is stored in |*al|. We don't actually process the content of the extensions
378 * yet, except to check their types. This function also runs the initialiser
379 * functions for all known extensions (whether we have collected them or not).
380 * If successful the caller is responsible for freeing the contents of |*res|.
382 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
383 * more than one extension of the same type in a ClientHello or ServerHello.
384 * This function returns 1 if all extensions are unique and we have parsed their
385 * types, and 0 if the extensions contain duplicates, could not be successfully
386 * found, or an internal error occurred. We only check duplicates for
387 * extensions that we know about. We ignore others.
389 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
390 RAW_EXTENSION **res, int *al, size_t *len)
392 PACKET extensions = *packet;
395 custom_ext_methods *exts = NULL;
396 RAW_EXTENSION *raw_extensions = NULL;
397 const EXTENSION_DEFINITION *thisexd;
402 * Initialise server side custom extensions. Client side is done during
403 * construction of extensions for the ClientHello.
405 if ((context & EXT_CLIENT_HELLO) != 0) {
406 exts = &s->cert->srv_ext;
407 custom_ext_init(&s->cert->srv_ext);
408 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
409 exts = &s->cert->cli_ext;
412 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
413 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
414 if (raw_extensions == NULL) {
415 *al = SSL_AD_INTERNAL_ERROR;
416 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
420 while (PACKET_remaining(&extensions) > 0) {
423 RAW_EXTENSION *thisex;
425 if (!PACKET_get_net_2(&extensions, &type) ||
426 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
427 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
428 *al = SSL_AD_DECODE_ERROR;
432 * Verify this extension is allowed. We only check duplicates for
433 * extensions that we recognise.
435 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
436 || (thisex != NULL && thisex->present == 1)) {
437 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
438 *al = SSL_AD_ILLEGAL_PARAMETER;
441 if (thisex != NULL) {
442 thisex->data = extension;
449 * Initialise all known extensions relevant to this context, whether we have
452 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
453 if(thisexd->init != NULL && (thisexd->context & context) != 0
454 && extension_is_relevant(s, thisexd->context, context)
455 && !thisexd->init(s, context)) {
456 *al = SSL_AD_INTERNAL_ERROR;
461 *res = raw_extensions;
467 OPENSSL_free(raw_extensions);
472 * Runs the parser for a given extension with index |idx|. |exts| contains the
473 * list of all parsed extensions previously collected by
474 * tls_collect_extensions(). The parser is only run if it is applicable for the
475 * given |context| and the parser has not already been run. If this is for a
476 * Certificate message, then we also provide the parser with the relevant
477 * Certificate |x| and its position in the |chainidx| with 0 being the first
478 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
479 * |*al| is populated with a suitable alert code. If an extension is not present
480 * this counted as success.
482 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
483 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
485 RAW_EXTENSION *currext = &exts[idx];
486 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
487 size_t chainidx, int *al) = NULL;
489 /* Skip if the extension is not present */
490 if (!currext->present)
494 s->ext.debug_cb(s, !s->server, currext->type,
495 PACKET_data(&currext->data),
496 PACKET_remaining(&currext->data),
499 /* Skip if we've already parsed this extension */
505 if (idx < OSSL_NELEM(ext_defs)) {
506 /* We are handling a built-in extension */
507 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
509 /* Check if extension is defined for our protocol. If not, skip */
510 if (!extension_is_relevant(s, extdef->context, context))
513 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
516 return parser(s, &currext->data, context, x, chainidx, al);
519 * If the parser is NULL we fall through to the custom extension
525 * This is a custom extension. We only allow this if it is a non
526 * resumed session on the server side.
528 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
529 * We're going to need a new mechanism for TLS1.3 to specify which
530 * messages to add the custom extensions to.
532 if ((!s->hit || !s->server)
534 & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
535 && custom_ext_parse(s, s->server, currext->type,
536 PACKET_data(&currext->data),
537 PACKET_remaining(&currext->data),
545 * Parse all remaining extensions that have not yet been parsed. Also calls the
546 * finalisation for all extensions at the end, whether we collected them or not.
547 * Returns 1 for success or 0 for failure. If we are working on a Certificate
548 * message then we also pass the Certificate |x| and its position in the
549 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
550 * populated with a suitable alert code.
552 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
553 size_t chainidx, int *al)
555 size_t i, numexts = OSSL_NELEM(ext_defs);
556 const EXTENSION_DEFINITION *thisexd;
558 /* Calculate the number of extensions in the extensions list */
559 if ((context & EXT_CLIENT_HELLO) != 0) {
560 numexts += s->cert->srv_ext.meths_count;
561 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
562 numexts += s->cert->cli_ext.meths_count;
565 /* Parse each extension in turn */
566 for (i = 0; i < numexts; i++) {
567 if (!tls_parse_extension(s, i, context, exts, x, chainidx, al))
572 * Finalise all known extensions relevant to this context, whether we have
575 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
576 if(thisexd->final != NULL
577 && (thisexd->context & context) != 0
578 && !thisexd->final(s, context, exts[i].present, al))
586 * Construct all the extensions relevant to the current |context| and write
587 * them to |pkt|. If this is an extension for a Certificate in a Certificate
588 * message, then |x| will be set to the Certificate we are handling, and
589 * |chainidx| will indicate the position in the chainidx we are processing (with
590 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
591 * failure occurs then |al| is populated with a suitable alert code. On a
592 * failure construction stops at the first extension to fail to construct.
594 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
595 X509 *x, size_t chainidx, int *al)
598 int addcustom = 0, min_version, max_version = 0, reason, tmpal;
599 const EXTENSION_DEFINITION *thisexd;
602 * Normally if something goes wrong during construction it's an internal
603 * error. We can always override this later.
605 tmpal = SSL_AD_INTERNAL_ERROR;
607 if (!WPACKET_start_sub_packet_u16(pkt)
609 * If extensions are of zero length then we don't even add the
610 * extensions length bytes to a ClientHello/ServerHello in SSLv3
612 || ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
613 && s->version == SSL3_VERSION
614 && !WPACKET_set_flags(pkt,
615 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
616 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
620 if ((context & EXT_CLIENT_HELLO) != 0) {
621 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
623 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
628 /* Add custom extensions first */
629 if ((context & EXT_CLIENT_HELLO) != 0) {
630 custom_ext_init(&s->cert->cli_ext);
632 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
634 * We already initialised the custom extensions during ClientHello
637 * TODO(TLS1.3): We're going to need a new custom extension mechanism
638 * for TLS1.3, so that custom extensions can specify which of the
639 * multiple message they wish to add themselves to.
644 if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) {
645 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
649 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
650 int (*construct)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
651 size_t chainidx, int *al);
653 /* Skip if not relevant for our context */
654 if ((thisexd->context & context) == 0)
657 construct = s->server ? thisexd->construct_stoc
658 : thisexd->construct_ctos;
660 /* Check if this extension is defined for our protocol. If not, skip */
662 && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY)
664 || (s->version == SSL3_VERSION
665 && (thisexd->context & EXT_SSL3_ALLOWED) == 0)
667 && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY)
670 && (thisexd->context & EXT_TLS1_3_ONLY) != 0
671 && (context & EXT_CLIENT_HELLO) == 0)
672 || ((thisexd->context & EXT_TLS1_3_ONLY) != 0
673 && (context & EXT_CLIENT_HELLO) != 0
674 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))
675 || construct == NULL)
678 if (!construct(s, pkt, context, x, chainidx, &tmpal))
682 if (!WPACKET_close(pkt)) {
683 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
695 * Built in extension finalisation and initialisation functions. All initialise
696 * or finalise the associated extension type for the given |context|. For
697 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
698 * otherwise. These functions return 1 on success or 0 on failure. In the event
699 * of a failure then |*al| is populated with a suitable error code.
702 static int final_renegotiate(SSL *s, unsigned int context, int sent,
707 * Check if we can connect to a server that doesn't support safe
710 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
711 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
713 *al = SSL_AD_HANDSHAKE_FAILURE;
714 SSLerr(SSL_F_FINAL_RENEGOTIATE,
715 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
722 /* Need RI if renegotiating */
724 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
726 *al = SSL_AD_HANDSHAKE_FAILURE;
727 SSLerr(SSL_F_FINAL_RENEGOTIATE,
728 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
736 static int init_server_name(SSL *s, unsigned int context)
739 s->servername_done = 0;
744 static int final_server_name(SSL *s, unsigned int context, int sent,
747 int ret = SSL_TLSEXT_ERR_NOACK;
748 int altmp = SSL_AD_UNRECOGNIZED_NAME;
750 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
751 ret = s->ctx->ext.servername_cb(s, &altmp,
752 s->ctx->ext.servername_arg);
753 else if (s->session_ctx != NULL
754 && s->session_ctx->ext.servername_cb != 0)
755 ret = s->session_ctx->ext.servername_cb(s, &altmp,
756 s->session_ctx->ext.servername_arg);
759 case SSL_TLSEXT_ERR_ALERT_FATAL:
763 case SSL_TLSEXT_ERR_ALERT_WARNING:
767 case SSL_TLSEXT_ERR_NOACK:
768 s->servername_done = 0;
776 #ifndef OPENSSL_NO_EC
777 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
780 unsigned long alg_k, alg_a;
785 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
786 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
789 * If we are client and using an elliptic curve cryptography cipher
790 * suite, then if server returns an EC point formats lists extension it
791 * must contain uncompressed.
793 if (s->ext.ecpointformats != NULL
794 && s->ext.ecpointformats_len > 0
795 && s->session->ext.ecpointformats != NULL
796 && s->session->ext.ecpointformats_len > 0
797 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
798 /* we are using an ECC cipher */
800 unsigned char *list = s->session->ext.ecpointformats;
802 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
803 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
806 if (i == s->session->ext.ecpointformats_len) {
807 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
808 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
817 static int init_session_ticket(SSL *s, unsigned int context)
820 s->ext.ticket_expected = 0;
825 #ifndef OPENSSL_NO_OCSP
826 static int init_status_request(SSL *s, unsigned int context)
829 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
832 * Ensure we get sensible values passed to tlsext_status_cb in the event
833 * that we don't receive a status message
835 OPENSSL_free(s->ext.ocsp.resp);
836 s->ext.ocsp.resp = NULL;
837 s->ext.ocsp.resp_len = 0;
844 #ifndef OPENSSL_NO_NEXTPROTONEG
845 static int init_npn(SSL *s, unsigned int context)
853 static int init_alpn(SSL *s, unsigned int context)
855 OPENSSL_free(s->s3->alpn_selected);
856 s->s3->alpn_selected = NULL;
858 s->s3->alpn_selected_len = 0;
859 OPENSSL_free(s->s3->alpn_proposed);
860 s->s3->alpn_proposed = NULL;
861 s->s3->alpn_proposed_len = 0;
866 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
868 const unsigned char *selected = NULL;
869 unsigned char selected_len = 0;
874 if (s->ctx->ext.alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
875 int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len,
876 s->s3->alpn_proposed,
877 (unsigned int)s->s3->alpn_proposed_len,
878 s->ctx->ext.alpn_select_cb_arg);
880 if (r == SSL_TLSEXT_ERR_OK) {
881 OPENSSL_free(s->s3->alpn_selected);
882 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
883 if (s->s3->alpn_selected == NULL) {
884 *al = SSL_AD_INTERNAL_ERROR;
887 s->s3->alpn_selected_len = selected_len;
888 #ifndef OPENSSL_NO_NEXTPROTONEG
889 /* ALPN takes precedence over NPN. */
893 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
901 static int init_sig_algs(SSL *s, unsigned int context)
903 /* Clear any signature algorithms extension received */
904 OPENSSL_free(s->s3->tmp.peer_sigalgs);
905 s->s3->tmp.peer_sigalgs = NULL;
910 #ifndef OPENSSL_NO_SRP
911 static int init_srp(SSL *s, unsigned int context)
913 OPENSSL_free(s->srp_ctx.login);
914 s->srp_ctx.login = NULL;
920 static int init_etm(SSL *s, unsigned int context)
927 static int init_ems(SSL *s, unsigned int context)
930 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
935 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
937 if (!s->server && s->hit) {
939 * Check extended master secret extension is consistent with
942 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
943 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
944 *al = SSL_AD_HANDSHAKE_FAILURE;
945 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
953 #ifndef OPENSSL_NO_SRTP
954 static int init_srtp(SSL *s, unsigned int context)
957 s->srtp_profile = NULL;
963 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
965 if (!sent && SSL_IS_TLS13(s)) {
966 *al = TLS13_AD_MISSING_EXTENSION;
967 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
974 #ifndef OPENSSL_NO_EC
975 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
977 if (!SSL_IS_TLS13(s))
984 * we have no key_share
986 * (we are not resuming
987 * OR the kex_mode doesn't allow non key_share resumes)
994 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
995 /* Nothing left we can do - just fail */
996 *al = SSL_AD_HANDSHAKE_FAILURE;
997 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1004 * we have no key_share
1007 * we didn't already send a HelloRetryRequest
1009 * the client sent a key_share extension
1011 * (we are not resuming
1012 * OR the kex_mode allows key_share resumes)
1014 * a shared group exists
1016 * send a HelloRetryRequest
1018 * we are not resuming
1020 * the kex_mode doesn't allow non key_share resumes
1024 if (s->server && s->s3->peer_tmp == NULL) {
1025 /* No suitable share */
1026 if (s->hello_retry_request == 0 && sent
1028 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1030 const unsigned char *pcurves, *pcurvestmp, *clntcurves;
1031 size_t num_curves, clnt_num_curves, i;
1032 unsigned int group_id = 0;
1034 /* Check if a shared group exists */
1036 /* Get the clients list of supported groups. */
1037 if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
1038 *al = SSL_AD_INTERNAL_ERROR;
1039 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1043 /* Get our list of available groups */
1044 if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
1045 *al = SSL_AD_INTERNAL_ERROR;
1046 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1050 /* Find the first group we allow that is also in client's list */
1051 for (i = 0, pcurvestmp = pcurves; i < num_curves;
1052 i++, pcurvestmp += 2) {
1053 group_id = bytestogroup(pcurvestmp);
1055 if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1))
1059 if (i < num_curves) {
1060 /* A shared group exists so send a HelloRetryRequest */
1061 s->s3->group_id = group_id;
1062 s->hello_retry_request = 1;
1067 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1068 /* Nothing left we can do - just fail */
1069 *al = SSL_AD_HANDSHAKE_FAILURE;
1070 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1075 /* We have a key_share so don't send any more HelloRetryRequest messages */
1077 s->hello_retry_request = 0;
1080 * For a client side resumption with no key_share we need to generate
1081 * the handshake secret (otherwise this is done during key_share
1084 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
1085 *al = SSL_AD_INTERNAL_ERROR;
1086 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1094 static int init_psk_kex_modes(SSL *s, unsigned int context)
1096 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1100 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1101 size_t binderoffset, const unsigned char *binderin,
1102 unsigned char *binderout,
1103 SSL_SESSION *sess, int sign)
1105 EVP_PKEY *mackey = NULL;
1106 EVP_MD_CTX *mctx = NULL;
1107 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1108 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1109 const char resumption_label[] = "resumption psk binder key";
1110 size_t bindersize, hashsize = EVP_MD_size(md);
1113 /* Generate the early_secret */
1114 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1115 sess->master_key_length,
1116 (unsigned char *)&s->early_secret)) {
1117 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1122 * Create the handshake hash for the binder key...the messages so far are
1125 mctx = EVP_MD_CTX_new();
1127 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1128 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1129 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1133 /* Generate the binder key */
1134 if (!tls13_hkdf_expand(s, md, s->early_secret,
1135 (unsigned char *)resumption_label,
1136 sizeof(resumption_label) - 1, hash, binderkey,
1138 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1142 /* Generate the finished key */
1143 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1144 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1148 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1149 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1154 * Get a hash of the ClientHello up to the start of the binders. If we are
1155 * following a HelloRetryRequest then this includes the hash of the first
1156 * ClientHello and the HelloRetryRequest itself.
1158 if (s->hello_retry_request) {
1162 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
1163 if (hdatalen <= 0) {
1164 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_HANDSHAKE_LENGTH);
1169 * For servers the handshake buffer data will include the second
1170 * ClientHello - which we don't want - so we need to take that bit off.
1173 if (hdatalen < s->init_num + SSL3_HM_HEADER_LENGTH) {
1174 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1177 hdatalen -= s->init_num + SSL3_HM_HEADER_LENGTH;
1180 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1181 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1186 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1187 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1188 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1192 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1193 if (mackey == NULL) {
1194 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1199 binderout = tmpbinder;
1201 bindersize = hashsize;
1202 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1203 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1204 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1205 || bindersize != hashsize) {
1206 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1213 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1214 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1218 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1219 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1220 EVP_PKEY_free(mackey);
1221 EVP_MD_CTX_free(mctx);