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 /* Must be before key_share */
241 TLSEXT_TYPE_psk_kex_modes,
242 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
243 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
244 tls_construct_ctos_psk_kex_modes, NULL
248 * Must be in this list after supported_groups. We need that to have
249 * been parsed before we do this one.
251 TLSEXT_TYPE_key_share,
252 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO
253 | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY
255 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
256 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
261 * Special unsolicited ServerHello extension only used when
262 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
264 TLSEXT_TYPE_cryptopro_bug,
265 EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
266 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
269 /* Must be immediately before pre_shared_key */
270 /* TODO(TLS1.3): Fix me */
274 /* We send this, but don't read it */
275 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
278 /* Required by the TLSv1.3 spec to always be the last extension */
280 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO | EXT_TLS_IMPLEMENTATION_ONLY
282 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, NULL,
283 tls_construct_ctos_psk, NULL
288 * Verify whether we are allowed to use the extension |type| in the current
289 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
290 * indicate the extension is not allowed. If returning 1 then |*found| is set to
291 * 1 if we found a definition for the extension, and |*idx| is set to its index
293 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
294 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
295 RAW_EXTENSION **found)
298 size_t builtin_num = OSSL_NELEM(ext_defs);
299 const EXTENSION_DEFINITION *thisext;
301 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
302 if (type == thisext->type) {
303 /* Check we're allowed to use this extension in this context */
304 if ((context & thisext->context) == 0)
307 if (SSL_IS_DTLS(s)) {
308 if ((thisext->context & EXT_TLS_ONLY) != 0)
310 } else if ((thisext->context & EXT_DTLS_ONLY) != 0) {
314 *found = &rawexlist[i];
319 if ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) == 0) {
321 * Custom extensions only apply to <=TLS1.2. This extension is unknown
322 * in this context - we allow it
328 /* Check the custom extensions */
330 for (i = builtin_num; i < builtin_num + meths->meths_count; i++) {
331 if (meths->meths[i - builtin_num].ext_type == type) {
332 *found = &rawexlist[i];
338 /* Unknown extension. We allow it */
344 * Check whether the context defined for an extension |extctx| means whether
345 * the extension is relevant for the current context |thisctx| or not. Returns
346 * 1 if the extension is relevant for this context, and 0 otherwise
348 static int extension_is_relevant(SSL *s, unsigned int extctx,
349 unsigned int thisctx)
352 && (extctx & EXT_TLS_IMPLEMENTATION_ONLY) != 0)
353 || (s->version == SSL3_VERSION
354 && (extctx & EXT_SSL3_ALLOWED) == 0)
356 && (extctx & EXT_TLS1_2_AND_BELOW_ONLY) != 0)
357 || (!SSL_IS_TLS13(s) && (extctx & EXT_TLS1_3_ONLY) != 0))
364 * Gather a list of all the extensions from the data in |packet]. |context|
365 * tells us which message this extension is for. The raw extension data is
366 * stored in |*res| on success. In the event of an error the alert type to use
367 * is stored in |*al|. We don't actually process the content of the extensions
368 * yet, except to check their types. This function also runs the initialiser
369 * functions for all known extensions (whether we have collected them or not).
370 * If successful the caller is responsible for freeing the contents of |*res|.
372 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
373 * more than one extension of the same type in a ClientHello or ServerHello.
374 * This function returns 1 if all extensions are unique and we have parsed their
375 * types, and 0 if the extensions contain duplicates, could not be successfully
376 * found, or an internal error occurred. We only check duplicates for
377 * extensions that we know about. We ignore others.
379 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
380 RAW_EXTENSION **res, int *al)
382 PACKET extensions = *packet;
384 custom_ext_methods *exts = NULL;
385 RAW_EXTENSION *raw_extensions = NULL;
386 const EXTENSION_DEFINITION *thisexd;
391 * Initialise server side custom extensions. Client side is done during
392 * construction of extensions for the ClientHello.
394 if ((context & EXT_CLIENT_HELLO) != 0) {
395 exts = &s->cert->srv_ext;
396 custom_ext_init(&s->cert->srv_ext);
397 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
398 exts = &s->cert->cli_ext;
401 raw_extensions = OPENSSL_zalloc((OSSL_NELEM(ext_defs)
402 + (exts != NULL ? exts->meths_count : 0))
403 * sizeof(*raw_extensions));
404 if (raw_extensions == NULL) {
405 *al = SSL_AD_INTERNAL_ERROR;
406 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
410 while (PACKET_remaining(&extensions) > 0) {
413 RAW_EXTENSION *thisex;
415 if (!PACKET_get_net_2(&extensions, &type) ||
416 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
417 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
418 *al = SSL_AD_DECODE_ERROR;
422 * Verify this extension is allowed. We only check duplicates for
423 * extensions that we recognise.
425 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
426 || (thisex != NULL && thisex->present == 1)) {
427 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
428 *al = SSL_AD_ILLEGAL_PARAMETER;
431 if (thisex != NULL) {
432 thisex->data = extension;
439 * Initialise all known extensions relevant to this context, whether we have
442 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
443 if(thisexd->init != NULL && (thisexd->context & context) != 0
444 && extension_is_relevant(s, thisexd->context, context)
445 && !thisexd->init(s, context)) {
446 *al = SSL_AD_INTERNAL_ERROR;
451 *res = raw_extensions;
455 OPENSSL_free(raw_extensions);
460 * Runs the parser for a given extension with index |idx|. |exts| contains the
461 * list of all parsed extensions previously collected by
462 * tls_collect_extensions(). The parser is only run if it is applicable for the
463 * given |context| and the parser has not already been run. If this is for a
464 * Certificate message, then we also provide the parser with the relevant
465 * Certificate |x| and its position in the |chainidx| with 0 being the first
466 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
467 * |*al| is populated with a suitable alert code. If an extension is not present
468 * this counted as success.
470 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
471 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
473 RAW_EXTENSION *currext = &exts[idx];
474 int (*parser)(SSL *s, PACKET *pkt, X509 *x, size_t chainidx, int *al) = NULL;
476 /* Skip if the extension is not present */
477 if (!currext->present)
481 s->ext.debug_cb(s, !s->server, currext->type,
482 PACKET_data(&currext->data),
483 PACKET_remaining(&currext->data),
486 /* Skip if we've already parsed this extension */
492 if (idx < OSSL_NELEM(ext_defs)) {
493 /* We are handling a built-in extension */
494 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
496 /* Check if extension is defined for our protocol. If not, skip */
497 if (!extension_is_relevant(s, extdef->context, context))
500 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
503 return parser(s, &currext->data, x, chainidx, al);
506 * If the parser is NULL we fall through to the custom extension
512 * This is a custom extension. We only allow this if it is a non
513 * resumed session on the server side.
515 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
516 * We're going to need a new mechanism for TLS1.3 to specify which
517 * messages to add the custom extensions to.
519 if ((!s->hit || !s->server)
521 & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
522 && custom_ext_parse(s, s->server, currext->type,
523 PACKET_data(&currext->data),
524 PACKET_remaining(&currext->data),
532 * Parse all remaining extensions that have not yet been parsed. Also calls the
533 * finalisation for all extensions at the end, whether we collected them or not.
534 * Returns 1 for success or 0 for failure. If we are working on a Certificate
535 * message then we also pass the Certificate |x| and its position in the
536 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
537 * populated with a suitable alert code.
539 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
540 size_t chainidx, int *al)
542 size_t i, numexts = OSSL_NELEM(ext_defs);
543 const EXTENSION_DEFINITION *thisexd;
545 /* Calculate the number of extensions in the extensions list */
546 if ((context & EXT_CLIENT_HELLO) != 0) {
547 numexts += s->cert->srv_ext.meths_count;
548 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
549 numexts += s->cert->cli_ext.meths_count;
552 /* Parse each extension in turn */
553 for (i = 0; i < numexts; i++) {
554 if (!tls_parse_extension(s, i, context, exts, x, chainidx, al))
559 * Finalise all known extensions relevant to this context, whether we have
562 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
563 if(thisexd->final != NULL
564 && (thisexd->context & context) != 0
565 && !thisexd->final(s, context, exts[i].present, al))
573 * Construct all the extensions relevant to the current |context| and write
574 * them to |pkt|. If this is an extension for a Certificate in a Certificate
575 * message, then |x| will be set to the Certificate we are handling, and
576 * |chainidx| will indicate the position in the chainidx we are processing (with
577 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
578 * failure occurs then |al| is populated with a suitable alert code. On a
579 * failure construction stops at the first extension to fail to construct.
581 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
582 X509 *x, size_t chainidx, int *al)
585 int addcustom = 0, min_version, max_version = 0, reason, tmpal;
586 const EXTENSION_DEFINITION *thisexd;
589 * Normally if something goes wrong during construction it's an internal
590 * error. We can always override this later.
592 tmpal = SSL_AD_INTERNAL_ERROR;
594 if (!WPACKET_start_sub_packet_u16(pkt)
596 * If extensions are of zero length then we don't even add the
597 * extensions length bytes to a ClientHello/ServerHello in SSLv3
599 || ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
600 && s->version == SSL3_VERSION
601 && !WPACKET_set_flags(pkt,
602 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
603 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
607 if ((context & EXT_CLIENT_HELLO) != 0) {
608 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
610 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
615 /* Add custom extensions first */
616 if ((context & EXT_CLIENT_HELLO) != 0) {
617 custom_ext_init(&s->cert->cli_ext);
619 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
621 * We already initialised the custom extensions during ClientHello
624 * TODO(TLS1.3): We're going to need a new custom extension mechanism
625 * for TLS1.3, so that custom extensions can specify which of the
626 * multiple message they wish to add themselves to.
631 if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) {
632 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
636 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
637 int (*construct)(SSL *s, WPACKET *pkt, X509 *x, size_t chainidx,
640 /* Skip if not relevant for our context */
641 if ((thisexd->context & context) == 0)
644 construct = s->server ? thisexd->construct_stoc
645 : thisexd->construct_ctos;
647 /* Check if this extension is defined for our protocol. If not, skip */
649 && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY)
651 || (s->version == SSL3_VERSION
652 && (thisexd->context & EXT_SSL3_ALLOWED) == 0)
654 && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY)
657 && (thisexd->context & EXT_TLS1_3_ONLY) != 0
658 && (context & EXT_CLIENT_HELLO) == 0)
659 || ((thisexd->context & EXT_TLS1_3_ONLY) != 0
660 && (context & EXT_CLIENT_HELLO) != 0
661 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))
662 || construct == NULL)
665 if (!construct(s, pkt, x, chainidx, &tmpal))
669 if (!WPACKET_close(pkt)) {
670 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
682 * Built in extension finalisation and initialisation functions. All initialise
683 * or finalise the associated extension type for the given |context|. For
684 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
685 * otherwise. These functions return 1 on success or 0 on failure. In the event
686 * of a failure then |*al| is populated with a suitable error code.
689 static int final_renegotiate(SSL *s, unsigned int context, int sent,
694 * Check if we can connect to a server that doesn't support safe
697 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
698 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
700 *al = SSL_AD_HANDSHAKE_FAILURE;
701 SSLerr(SSL_F_FINAL_RENEGOTIATE,
702 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
709 /* Need RI if renegotiating */
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);
723 static int init_server_name(SSL *s, unsigned int context)
726 s->servername_done = 0;
731 static int final_server_name(SSL *s, unsigned int context, int sent,
734 int ret = SSL_TLSEXT_ERR_NOACK;
735 int altmp = SSL_AD_UNRECOGNIZED_NAME;
737 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
738 ret = s->ctx->ext.servername_cb(s, &altmp,
739 s->ctx->ext.servername_arg);
740 else if (s->initial_ctx != NULL
741 && s->initial_ctx->ext.servername_cb != 0)
742 ret = s->initial_ctx->ext.servername_cb(s, &altmp,
743 s->initial_ctx->ext.servername_arg);
746 case SSL_TLSEXT_ERR_ALERT_FATAL:
750 case SSL_TLSEXT_ERR_ALERT_WARNING:
754 case SSL_TLSEXT_ERR_NOACK:
755 s->servername_done = 0;
763 #ifndef OPENSSL_NO_EC
764 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
767 unsigned long alg_k, alg_a;
772 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
773 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
776 * If we are client and using an elliptic curve cryptography cipher
777 * suite, then if server returns an EC point formats lists extension it
778 * must contain uncompressed.
780 if (s->ext.ecpointformats != NULL
781 && s->ext.ecpointformats_len > 0
782 && s->session->ext.ecpointformats != NULL
783 && s->session->ext.ecpointformats_len > 0
784 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
785 /* we are using an ECC cipher */
787 unsigned char *list = s->session->ext.ecpointformats;
789 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
790 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
793 if (i == s->session->ext.ecpointformats_len) {
794 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
795 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
804 static int init_session_ticket(SSL *s, unsigned int context)
807 s->ext.ticket_expected = 0;
812 #ifndef OPENSSL_NO_OCSP
813 static int init_status_request(SSL *s, unsigned int context)
816 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
819 * Ensure we get sensible values passed to tlsext_status_cb in the event
820 * that we don't receive a status message
822 OPENSSL_free(s->ext.ocsp.resp);
823 s->ext.ocsp.resp = NULL;
824 s->ext.ocsp.resp_len = 0;
831 #ifndef OPENSSL_NO_NEXTPROTONEG
832 static int init_npn(SSL *s, unsigned int context)
840 static int init_alpn(SSL *s, unsigned int context)
842 OPENSSL_free(s->s3->alpn_selected);
843 s->s3->alpn_selected = NULL;
845 s->s3->alpn_selected_len = 0;
846 OPENSSL_free(s->s3->alpn_proposed);
847 s->s3->alpn_proposed = NULL;
848 s->s3->alpn_proposed_len = 0;
853 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
855 const unsigned char *selected = NULL;
856 unsigned char selected_len = 0;
861 if (s->ctx->ext.alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
862 int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len,
863 s->s3->alpn_proposed,
864 (unsigned int)s->s3->alpn_proposed_len,
865 s->ctx->ext.alpn_select_cb_arg);
867 if (r == SSL_TLSEXT_ERR_OK) {
868 OPENSSL_free(s->s3->alpn_selected);
869 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
870 if (s->s3->alpn_selected == NULL) {
871 *al = SSL_AD_INTERNAL_ERROR;
874 s->s3->alpn_selected_len = selected_len;
875 #ifndef OPENSSL_NO_NEXTPROTONEG
876 /* ALPN takes precedence over NPN. */
880 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
888 static int init_sig_algs(SSL *s, unsigned int context)
890 /* Clear any signature algorithms extension received */
891 OPENSSL_free(s->s3->tmp.peer_sigalgs);
892 s->s3->tmp.peer_sigalgs = NULL;
897 #ifndef OPENSSL_NO_SRP
898 static int init_srp(SSL *s, unsigned int context)
900 OPENSSL_free(s->srp_ctx.login);
901 s->srp_ctx.login = NULL;
907 static int init_etm(SSL *s, unsigned int context)
909 s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
914 static int init_ems(SSL *s, unsigned int context)
917 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
922 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
924 if (!s->server && s->hit) {
926 * Check extended master secret extension is consistent with
929 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
930 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
931 *al = SSL_AD_HANDSHAKE_FAILURE;
932 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
940 #ifndef OPENSSL_NO_SRTP
941 static int init_srtp(SSL *s, unsigned int context)
944 s->srtp_profile = NULL;
950 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
952 if (!sent && SSL_IS_TLS13(s)) {
953 *al = TLS13_AD_MISSING_EXTENSION;
954 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
962 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
964 if (!SSL_IS_TLS13(s))
969 * we have no key_share
971 * (we are not resuming
972 * OR the kex_mode doesn't allow non key_share resumes)
976 if (((s->server && s->s3->peer_tmp == NULL) || (!s->server && !sent))
978 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
979 /* No suitable share */
980 /* TODO(TLS1.3): Send a HelloRetryRequest */
981 *al = SSL_AD_HANDSHAKE_FAILURE;
982 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
987 * For a client side resumption with no key_share we need to generate
988 * the handshake secret (otherwise this is done during key_share
991 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
992 *al = SSL_AD_INTERNAL_ERROR;
993 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1000 static int init_psk_kex_modes(SSL *s, unsigned int context)
1002 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1007 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1008 size_t binderoffset, const unsigned char *binderin,
1009 unsigned char *binderout,
1010 SSL_SESSION *sess, int sign)
1012 EVP_PKEY *mackey = NULL;
1013 EVP_MD_CTX *mctx = NULL;
1014 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1015 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1016 const char resumption_label[] = "resumption psk binder key";
1017 size_t hashsize = EVP_MD_size(md), bindersize;
1020 /* Generate the early_secret */
1021 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1022 sess->master_key_length,
1023 (unsigned char *)&s->early_secret)) {
1024 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1029 * Create the handshake hash for the binder key...the messages so far are
1032 mctx = EVP_MD_CTX_new();
1034 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1035 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1036 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1040 /* Generate the binder key */
1041 if (!tls13_hkdf_expand(s, md, s->early_secret,
1042 (unsigned char *)resumption_label,
1043 sizeof(resumption_label) - 1, hash, binderkey,
1045 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1049 /* Generate the finished key */
1050 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1051 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1056 * Get a hash of the ClientHello up to the start of the binders.
1057 * TODO(TLS1.3): This will need to be tweaked when we implement
1058 * HelloRetryRequest to include the digest of the previous messages here.
1060 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0
1061 || EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1062 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1063 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1067 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1068 if (mackey == NULL) {
1069 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1074 binderout = tmpbinder;
1076 bindersize = hashsize;
1077 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1078 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1079 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1080 || bindersize != hashsize) {
1081 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1088 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1089 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1093 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1094 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1095 EVP_PKEY_free(mackey);
1096 EVP_MD_CTX_free(mctx);