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);
39 static int final_key_share(SSL *s, unsigned int context, int sent, int *al);
40 #ifndef OPENSSL_NO_SRTP
41 static int init_srtp(SSL *s, unsigned int context);
43 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al);
45 /* Structure to define a built-in extension */
46 typedef struct extensions_definition_st {
47 /* The defined type for the extension */
50 * The context that this extension applies to, e.g. what messages and
55 * Initialise extension before parsing. Always called for relevant contexts
56 * even if extension not present
58 int (*init)(SSL *s, unsigned int context);
59 /* Parse extension sent from client to server */
60 int (*parse_ctos)(SSL *s, PACKET *pkt, X509 *x, size_t chainidx, int *al);
61 /* Parse extension send from server to client */
62 int (*parse_stoc)(SSL *s, PACKET *pkt, X509 *x, size_t chainidx, int *al);
63 /* Construct extension sent from server to client */
64 int (*construct_stoc)(SSL *s, WPACKET *pkt, X509 *x, size_t chainidx,
66 /* Construct extension sent from client to server */
67 int (*construct_ctos)(SSL *s, WPACKET *pkt, X509 *x, size_t chainidx,
70 * Finalise extension after parsing. Always called where an extensions was
71 * initialised even if the extension was not present. |sent| is set to 1 if
72 * the extension was seen, or 0 otherwise.
74 int (*final)(SSL *s, unsigned int context, int sent, int *al);
75 } EXTENSION_DEFINITION;
78 * Definitions of all built-in extensions. NOTE: Changes in the number or order
79 * of these extensions should be mirrored with equivalent changes to the
80 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
81 * Each extension has an initialiser, a client and
82 * server side parser and a finaliser. The initialiser is called (if the
83 * extension is relevant to the given context) even if we did not see the
84 * extension in the message that we received. The parser functions are only
85 * called if we see the extension in the message. The finalisers are always
86 * called if the initialiser was called.
87 * There are also server and client side constructor functions which are always
88 * called during message construction if the extension is relevant for the
90 * The initialisation, parsing, finalisation and construction functions are
91 * always called in the order defined in this list. Some extensions may depend
92 * on others having been processed first, so the order of this list is
94 * The extension context is defined by a series of flags which specify which
95 * messages the extension is relevant to. These flags also specify whether the
96 * extension is relevant to a particular protocol or protocol version.
98 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
100 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
101 static const EXTENSION_DEFINITION ext_defs[] = {
103 TLSEXT_TYPE_renegotiate,
104 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_SSL3_ALLOWED
105 | EXT_TLS1_2_AND_BELOW_ONLY,
106 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
107 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
111 TLSEXT_TYPE_server_name,
112 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
113 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
115 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
116 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
119 #ifndef OPENSSL_NO_SRP
122 EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
123 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
128 #ifndef OPENSSL_NO_EC
130 TLSEXT_TYPE_ec_point_formats,
131 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
132 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
133 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
137 TLSEXT_TYPE_supported_groups,
138 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
139 NULL, tls_parse_ctos_supported_groups, NULL,
140 NULL /* TODO(TLS1.3): Need to add this */,
141 tls_construct_ctos_supported_groups, NULL
148 TLSEXT_TYPE_session_ticket,
149 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
150 init_session_ticket, tls_parse_ctos_session_ticket,
151 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
152 tls_construct_ctos_session_ticket, NULL
155 TLSEXT_TYPE_signature_algorithms,
157 init_sig_algs, tls_parse_ctos_sig_algs, NULL, NULL,
158 tls_construct_ctos_sig_algs, final_sig_algs
160 #ifndef OPENSSL_NO_OCSP
162 TLSEXT_TYPE_status_request,
163 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
164 | EXT_TLS1_3_CERTIFICATE,
165 init_status_request, tls_parse_ctos_status_request,
166 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
167 tls_construct_ctos_status_request, NULL
172 #ifndef OPENSSL_NO_NEXTPROTONEG
174 TLSEXT_TYPE_next_proto_neg,
175 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
176 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
177 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
184 * Must appear in this list after server_name so that finalisation
185 * happens after server_name callbacks
187 TLSEXT_TYPE_application_layer_protocol_negotiation,
188 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
189 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
190 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
191 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
193 #ifndef OPENSSL_NO_SRTP
195 TLSEXT_TYPE_use_srtp,
196 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
197 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY,
198 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
199 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
205 TLSEXT_TYPE_encrypt_then_mac,
206 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
207 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
208 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
210 #ifndef OPENSSL_NO_CT
212 TLSEXT_TYPE_signed_certificate_timestamp,
213 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
214 | EXT_TLS1_3_CERTIFICATE,
217 * No server side support for this, but can be provided by a custom
218 * extension. This is an exception to the rule that custom extensions
219 * cannot override built in ones.
221 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
227 TLSEXT_TYPE_extended_master_secret,
228 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
229 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
230 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
233 TLSEXT_TYPE_supported_versions,
234 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
236 /* Processed inline as part of version selection */
237 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
240 TLSEXT_TYPE_psk_kex_modes,
241 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
242 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
243 tls_construct_ctos_psk_kex_modes, NULL
247 * Must be in this list after supported_groups. We need that to have
248 * been parsed before we do this one.
250 TLSEXT_TYPE_key_share,
251 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO
252 | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY
254 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
255 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
260 * Special unsolicited ServerHello extension only used when
261 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
263 TLSEXT_TYPE_cryptopro_bug,
264 EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
265 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
268 /* Must be immediately before pre_shared_key */
269 /* TODO(TLS1.3): Fix me */
273 /* We send this, but don't read it */
274 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
277 /* Required by the TLSv1.3 spec to always be the last extension */
279 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO | EXT_TLS_IMPLEMENTATION_ONLY
281 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
282 tls_construct_ctos_psk, NULL
287 * Verify whether we are allowed to use the extension |type| in the current
288 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
289 * indicate the extension is not allowed. If returning 1 then |*found| is set to
290 * 1 if we found a definition for the extension, and |*idx| is set to its index
292 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
293 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
294 RAW_EXTENSION **found)
297 size_t builtin_num = OSSL_NELEM(ext_defs);
298 const EXTENSION_DEFINITION *thisext;
300 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
301 if (type == thisext->type) {
302 /* Check we're allowed to use this extension in this context */
303 if ((context & thisext->context) == 0)
306 if (SSL_IS_DTLS(s)) {
307 if ((thisext->context & EXT_TLS_ONLY) != 0)
309 } else if ((thisext->context & EXT_DTLS_ONLY) != 0) {
313 *found = &rawexlist[i];
318 if ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) == 0) {
320 * Custom extensions only apply to <=TLS1.2. This extension is unknown
321 * in this context - we allow it
327 /* Check the custom extensions */
329 for (i = builtin_num; i < builtin_num + meths->meths_count; i++) {
330 if (meths->meths[i - builtin_num].ext_type == type) {
331 *found = &rawexlist[i];
337 /* Unknown extension. We allow it */
343 * Check whether the context defined for an extension |extctx| means whether
344 * the extension is relevant for the current context |thisctx| or not. Returns
345 * 1 if the extension is relevant for this context, and 0 otherwise
347 static int extension_is_relevant(SSL *s, unsigned int extctx,
348 unsigned int thisctx)
351 && (extctx & EXT_TLS_IMPLEMENTATION_ONLY) != 0)
352 || (s->version == SSL3_VERSION
353 && (extctx & EXT_SSL3_ALLOWED) == 0)
355 && (extctx & EXT_TLS1_2_AND_BELOW_ONLY) != 0)
356 || (!SSL_IS_TLS13(s) && (extctx & EXT_TLS1_3_ONLY) != 0))
363 * Gather a list of all the extensions from the data in |packet]. |context|
364 * tells us which message this extension is for. The raw extension data is
365 * stored in |*res| on success. In the event of an error the alert type to use
366 * is stored in |*al|. We don't actually process the content of the extensions
367 * yet, except to check their types. This function also runs the initialiser
368 * functions for all known extensions (whether we have collected them or not).
369 * If successful the caller is responsible for freeing the contents of |*res|.
371 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
372 * more than one extension of the same type in a ClientHello or ServerHello.
373 * This function returns 1 if all extensions are unique and we have parsed their
374 * types, and 0 if the extensions contain duplicates, could not be successfully
375 * found, or an internal error occurred. We only check duplicates for
376 * extensions that we know about. We ignore others.
378 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
379 RAW_EXTENSION **res, int *al)
381 PACKET extensions = *packet;
383 custom_ext_methods *exts = NULL;
384 RAW_EXTENSION *raw_extensions = NULL;
385 const EXTENSION_DEFINITION *thisexd;
390 * Initialise server side custom extensions. Client side is done during
391 * construction of extensions for the ClientHello.
393 if ((context & EXT_CLIENT_HELLO) != 0) {
394 exts = &s->cert->srv_ext;
395 custom_ext_init(&s->cert->srv_ext);
396 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
397 exts = &s->cert->cli_ext;
400 raw_extensions = OPENSSL_zalloc((OSSL_NELEM(ext_defs)
401 + (exts != NULL ? exts->meths_count : 0))
402 * sizeof(*raw_extensions));
403 if (raw_extensions == NULL) {
404 *al = SSL_AD_INTERNAL_ERROR;
405 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
409 while (PACKET_remaining(&extensions) > 0) {
412 RAW_EXTENSION *thisex;
414 if (!PACKET_get_net_2(&extensions, &type) ||
415 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
416 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
417 *al = SSL_AD_DECODE_ERROR;
421 * Verify this extension is allowed. We only check duplicates for
422 * extensions that we recognise.
424 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
425 || (thisex != NULL && thisex->present == 1)) {
426 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
427 *al = SSL_AD_ILLEGAL_PARAMETER;
430 if (thisex != NULL) {
431 thisex->data = extension;
438 * Initialise all known extensions relevant to this context, whether we have
441 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
442 if(thisexd->init != NULL && (thisexd->context & context) != 0
443 && extension_is_relevant(s, thisexd->context, context)
444 && !thisexd->init(s, context)) {
445 *al = SSL_AD_INTERNAL_ERROR;
450 *res = raw_extensions;
454 OPENSSL_free(raw_extensions);
459 * Runs the parser for a given extension with index |idx|. |exts| contains the
460 * list of all parsed extensions previously collected by
461 * tls_collect_extensions(). The parser is only run if it is applicable for the
462 * given |context| and the parser has not already been run. If this is for a
463 * Certificate message, then we also provide the parser with the relevant
464 * Certificate |x| and its position in the |chainidx| with 0 being the first
465 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
466 * |*al| is populated with a suitable alert code. If an extension is not present
467 * this counted as success.
469 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
470 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
472 RAW_EXTENSION *currext = &exts[idx];
473 int (*parser)(SSL *s, PACKET *pkt, X509 *x, size_t chainidx, int *al) = NULL;
475 /* Skip if the extension is not present */
476 if (!currext->present)
480 s->ext.debug_cb(s, !s->server, currext->type,
481 PACKET_data(&currext->data),
482 PACKET_remaining(&currext->data),
485 /* Skip if we've already parsed this extension */
491 if (idx < OSSL_NELEM(ext_defs)) {
492 /* We are handling a built-in extension */
493 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
495 /* Check if extension is defined for our protocol. If not, skip */
496 if (!extension_is_relevant(s, extdef->context, context))
499 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
502 return parser(s, &currext->data, x, chainidx, al);
505 * If the parser is NULL we fall through to the custom extension
511 * This is a custom extension. We only allow this if it is a non
512 * resumed session on the server side.
514 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
515 * We're going to need a new mechanism for TLS1.3 to specify which
516 * messages to add the custom extensions to.
518 if ((!s->hit || !s->server)
520 & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
521 && custom_ext_parse(s, s->server, currext->type,
522 PACKET_data(&currext->data),
523 PACKET_remaining(&currext->data),
531 * Parse all remaining extensions that have not yet been parsed. Also calls the
532 * finalisation for all extensions at the end, whether we collected them or not.
533 * Returns 1 for success or 0 for failure. If we are working on a Certificate
534 * message then we also pass the Certificate |x| and its position in the
535 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
536 * populated with a suitable alert code.
538 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
539 size_t chainidx, int *al)
541 size_t i, numexts = OSSL_NELEM(ext_defs);
542 const EXTENSION_DEFINITION *thisexd;
544 /* Calculate the number of extensions in the extensions list */
545 if ((context & EXT_CLIENT_HELLO) != 0) {
546 numexts += s->cert->srv_ext.meths_count;
547 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
548 numexts += s->cert->cli_ext.meths_count;
551 /* Parse each extension in turn */
552 for (i = 0; i < numexts; i++) {
553 if (!tls_parse_extension(s, i, context, exts, x, chainidx, al))
558 * Finalise all known extensions relevant to this context, whether we have
561 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
562 if(thisexd->final != NULL
563 && (thisexd->context & context) != 0
564 && !thisexd->final(s, context, exts[i].present, al))
572 * Construct all the extensions relevant to the current |context| and write
573 * them to |pkt|. If this is an extension for a Certificate in a Certificate
574 * message, then |x| will be set to the Certificate we are handling, and
575 * |chainidx| will indicate the position in the chainidx we are processing (with
576 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
577 * failure occurs then |al| is populated with a suitable alert code. On a
578 * failure construction stops at the first extension to fail to construct.
580 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
581 X509 *x, size_t chainidx, int *al)
584 int addcustom = 0, min_version, max_version = 0, reason, tmpal;
585 const EXTENSION_DEFINITION *thisexd;
588 * Normally if something goes wrong during construction it's an internal
589 * error. We can always override this later.
591 tmpal = SSL_AD_INTERNAL_ERROR;
593 if (!WPACKET_start_sub_packet_u16(pkt)
595 * If extensions are of zero length then we don't even add the
596 * extensions length bytes to a ClientHello/ServerHello in SSLv3
598 || ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
599 && s->version == SSL3_VERSION
600 && !WPACKET_set_flags(pkt,
601 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
602 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
606 if ((context & EXT_CLIENT_HELLO) != 0) {
607 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
609 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
614 /* Add custom extensions first */
615 if ((context & EXT_CLIENT_HELLO) != 0) {
616 custom_ext_init(&s->cert->cli_ext);
618 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
620 * We already initialised the custom extensions during ClientHello
623 * TODO(TLS1.3): We're going to need a new custom extension mechanism
624 * for TLS1.3, so that custom extensions can specify which of the
625 * multiple message they wish to add themselves to.
630 if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) {
631 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
635 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
636 int (*construct)(SSL *s, WPACKET *pkt, X509 *x, size_t chainidx,
639 /* Skip if not relevant for our context */
640 if ((thisexd->context & context) == 0)
643 construct = s->server ? thisexd->construct_stoc
644 : thisexd->construct_ctos;
646 /* Check if this extension is defined for our protocol. If not, skip */
648 && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY)
650 || (s->version == SSL3_VERSION
651 && (thisexd->context & EXT_SSL3_ALLOWED) == 0)
653 && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY)
656 && (thisexd->context & EXT_TLS1_3_ONLY) != 0
657 && (context & EXT_CLIENT_HELLO) == 0)
658 || ((thisexd->context & EXT_TLS1_3_ONLY) != 0
659 && (context & EXT_CLIENT_HELLO) != 0
660 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))
661 || construct == NULL)
664 if (!construct(s, pkt, x, chainidx, &tmpal))
668 if (!WPACKET_close(pkt)) {
669 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
681 * Built in extension finalisation and initialisation functions. All initialise
682 * or finalise the associated extension type for the given |context|. For
683 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
684 * otherwise. These functions return 1 on success or 0 on failure. In the event
685 * of a failure then |*al| is populated with a suitable error code.
688 static int final_renegotiate(SSL *s, unsigned int context, int sent,
693 * Check if we can connect to a server that doesn't support safe
696 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
697 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
699 *al = SSL_AD_HANDSHAKE_FAILURE;
700 SSLerr(SSL_F_FINAL_RENEGOTIATE,
701 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
708 /* Need RI if renegotiating */
710 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
712 *al = SSL_AD_HANDSHAKE_FAILURE;
713 SSLerr(SSL_F_FINAL_RENEGOTIATE,
714 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
722 static int init_server_name(SSL *s, unsigned int context)
725 s->servername_done = 0;
730 static int final_server_name(SSL *s, unsigned int context, int sent,
733 int ret = SSL_TLSEXT_ERR_NOACK;
734 int altmp = SSL_AD_UNRECOGNIZED_NAME;
736 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
737 ret = s->ctx->ext.servername_cb(s, &altmp,
738 s->ctx->ext.servername_arg);
739 else if (s->initial_ctx != NULL
740 && s->initial_ctx->ext.servername_cb != 0)
741 ret = s->initial_ctx->ext.servername_cb(s, &altmp,
742 s->initial_ctx->ext.servername_arg);
745 case SSL_TLSEXT_ERR_ALERT_FATAL:
749 case SSL_TLSEXT_ERR_ALERT_WARNING:
753 case SSL_TLSEXT_ERR_NOACK:
754 s->servername_done = 0;
762 #ifndef OPENSSL_NO_EC
763 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
766 unsigned long alg_k, alg_a;
771 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
772 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
775 * If we are client and using an elliptic curve cryptography cipher
776 * suite, then if server returns an EC point formats lists extension it
777 * must contain uncompressed.
779 if (s->ext.ecpointformats != NULL
780 && s->ext.ecpointformats_len > 0
781 && s->session->ext.ecpointformats != NULL
782 && s->session->ext.ecpointformats_len > 0
783 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
784 /* we are using an ECC cipher */
786 unsigned char *list = s->session->ext.ecpointformats;
788 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
789 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
792 if (i == s->session->ext.ecpointformats_len) {
793 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
794 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
803 static int init_session_ticket(SSL *s, unsigned int context)
806 s->ext.ticket_expected = 0;
811 #ifndef OPENSSL_NO_OCSP
812 static int init_status_request(SSL *s, unsigned int context)
815 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
818 * Ensure we get sensible values passed to tlsext_status_cb in the event
819 * that we don't receive a status message
821 OPENSSL_free(s->ext.ocsp.resp);
822 s->ext.ocsp.resp = NULL;
823 s->ext.ocsp.resp_len = 0;
830 #ifndef OPENSSL_NO_NEXTPROTONEG
831 static int init_npn(SSL *s, unsigned int context)
839 static int init_alpn(SSL *s, unsigned int context)
841 OPENSSL_free(s->s3->alpn_selected);
842 s->s3->alpn_selected = NULL;
844 s->s3->alpn_selected_len = 0;
845 OPENSSL_free(s->s3->alpn_proposed);
846 s->s3->alpn_proposed = NULL;
847 s->s3->alpn_proposed_len = 0;
852 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
854 const unsigned char *selected = NULL;
855 unsigned char selected_len = 0;
860 if (s->ctx->ext.alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
861 int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len,
862 s->s3->alpn_proposed,
863 (unsigned int)s->s3->alpn_proposed_len,
864 s->ctx->ext.alpn_select_cb_arg);
866 if (r == SSL_TLSEXT_ERR_OK) {
867 OPENSSL_free(s->s3->alpn_selected);
868 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
869 if (s->s3->alpn_selected == NULL) {
870 *al = SSL_AD_INTERNAL_ERROR;
873 s->s3->alpn_selected_len = selected_len;
874 #ifndef OPENSSL_NO_NEXTPROTONEG
875 /* ALPN takes precedence over NPN. */
879 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
887 static int init_sig_algs(SSL *s, unsigned int context)
889 /* Clear any signature algorithms extension received */
890 OPENSSL_free(s->s3->tmp.peer_sigalgs);
891 s->s3->tmp.peer_sigalgs = NULL;
896 #ifndef OPENSSL_NO_SRP
897 static int init_srp(SSL *s, unsigned int context)
899 OPENSSL_free(s->srp_ctx.login);
900 s->srp_ctx.login = NULL;
906 static int init_etm(SSL *s, unsigned int context)
908 s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
913 static int init_ems(SSL *s, unsigned int context)
916 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
921 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
923 if (!s->server && s->hit) {
925 * Check extended master secret extension is consistent with
928 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
929 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
930 *al = SSL_AD_HANDSHAKE_FAILURE;
931 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
939 #ifndef OPENSSL_NO_SRTP
940 static int init_srtp(SSL *s, unsigned int context)
943 s->srtp_profile = NULL;
949 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
951 if (!sent && SSL_IS_TLS13(s)) {
952 *al = TLS13_AD_MISSING_EXTENSION;
953 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
961 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
963 if (!SSL_IS_TLS13(s))
968 * we have no key_share
970 * (we are not resuming
971 * OR the kex_mode doesn't allow non key_share resumes)
975 if (((s->server && s->s3->peer_tmp == NULL) || (!s->server && !sent))
977 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
978 /* No suitable share */
979 /* TODO(TLS1.3): Send a HelloRetryRequest */
980 *al = SSL_AD_HANDSHAKE_FAILURE;
981 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
986 * For a client side resumption with no key_share we need to generate
987 * the handshake secret (otherwise this is done during key_share
990 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
991 *al = SSL_AD_INTERNAL_ERROR;
992 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
999 static int init_psk_kex_modes(SSL *s, unsigned int context)
1001 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1005 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1006 size_t binderoffset, const unsigned char *binderin,
1007 unsigned char *binderout,
1008 SSL_SESSION *sess, int sign)
1010 EVP_PKEY *mackey = NULL;
1011 EVP_MD_CTX *mctx = NULL;
1012 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1013 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1014 const char resumption_label[] = "resumption psk binder key";
1015 size_t bindersize, hashsize = EVP_MD_size(md);
1018 /* Generate the early_secret */
1019 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1020 sess->master_key_length,
1021 (unsigned char *)&s->early_secret)) {
1022 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1027 * Create the handshake hash for the binder key...the messages so far are
1030 mctx = EVP_MD_CTX_new();
1032 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1033 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1034 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1038 /* Generate the binder key */
1039 if (!tls13_hkdf_expand(s, md, s->early_secret,
1040 (unsigned char *)resumption_label,
1041 sizeof(resumption_label) - 1, hash, binderkey,
1043 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1047 /* Generate the finished key */
1048 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1049 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1054 * Get a hash of the ClientHello up to the start of the binders.
1055 * TODO(TLS1.3): This will need to be tweaked when we implement
1056 * HelloRetryRequest to include the digest of the previous messages here.
1058 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0
1059 || EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1060 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1061 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1065 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1066 if (mackey == NULL) {
1067 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1072 binderout = tmpbinder;
1074 bindersize = hashsize;
1075 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1076 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1077 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1078 || bindersize != hashsize) {
1079 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1086 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1087 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1091 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1092 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1093 EVP_PKEY_free(mackey);
1094 EVP_MD_CTX_free(mctx);