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 static int init_status_request(SSL *s, unsigned int context);
24 static int final_status_request(SSL *s, unsigned int context, int sent,
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 #ifndef OPENSSL_NO_SRTP
39 static int init_srtp(SSL *s, unsigned int context);
42 /* Structure to define a built-in extension */
43 typedef struct extensions_definition_st {
44 /* The defined type for the extension */
47 * The context that this extension applies to, e.g. what messages and
52 * Initialise extension before parsing. Always called for relevant contexts
53 * even if extension not present
55 int (*init)(SSL *s, unsigned int context);
56 /* Parse extension sent from client to server */
57 int (*parse_ctos)(SSL *s, PACKET *pkt, int *al);
58 /* Parse extension send from server to client */
59 int (*parse_stoc)(SSL *s, PACKET *pkt, int *al);
60 /* Construct extension sent from server to client */
61 int (*construct_stoc)(SSL *s, WPACKET *pkt, int *al);
62 /* Construct extension sent from client to server */
63 int (*construct_ctos)(SSL *s, WPACKET *pkt, int *al);
65 * Finalise extension after parsing. Always called where an extensions was
66 * initialised even if the extension was not present. |sent| is set to 1 if
67 * the extension was seen, or 0 otherwise.
69 int (*final)(SSL *s, unsigned int context, int sent, int *al);
70 } EXTENSION_DEFINITION;
73 * Definitions of all built-in extensions. NOTE: Changes in the number or order
74 * of these extensions should be mirrored with equivalent changes to the indexes
75 * defined in statem_locl.h.
76 * Each extension has an initialiser, a client and
77 * server side parser and a finaliser. The initialiser is called (if the
78 * extension is relevant to the given context) even if we did not see the
79 * extension in the message that we received. The parser functions are only
80 * called if we see the extension in the message. The finalisers are always
81 * called if the initialiser was called.
82 * There are also server and client side constructor functions which are always
83 * called during message construction if the extension is relevant for the
85 * The initialisation, parsing, finalisation and construction functions are
86 * always called in the order defined in this list. Some extensions may depend
87 * on others having been processed first, so the order of this list is
89 * The extension context is defined by a series of flags which specify which
90 * messages the extension is relevant to. These flags also specify whether the
91 * extension is relevant to a paricular protocol or protocol version.
93 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
95 static const EXTENSION_DEFINITION ext_defs[] = {
97 TLSEXT_TYPE_renegotiate,
98 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_SSL3_ALLOWED
99 | EXT_TLS1_2_AND_BELOW_ONLY,
100 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
101 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
105 TLSEXT_TYPE_server_name,
106 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
107 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
109 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
110 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
113 #ifndef OPENSSL_NO_SRP
116 EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
117 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
120 #ifndef OPENSSL_NO_EC
122 TLSEXT_TYPE_ec_point_formats,
123 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
124 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
125 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
129 TLSEXT_TYPE_supported_groups,
130 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
131 NULL, tls_parse_ctos_supported_groups, NULL,
132 NULL /* TODO(TLS1.3): Need to add this */,
133 tls_construct_ctos_supported_groups, NULL
137 TLSEXT_TYPE_session_ticket,
138 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
139 init_session_ticket, tls_parse_ctos_session_ticket,
140 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
141 tls_construct_ctos_session_ticket, NULL
144 TLSEXT_TYPE_signature_algorithms,
146 init_sig_algs, tls_parse_ctos_sig_algs, NULL, NULL,
147 tls_construct_ctos_sig_algs, NULL
149 #ifndef OPENSSL_NO_OCSP
151 TLSEXT_TYPE_status_request,
152 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
153 | EXT_TLS1_3_CERTIFICATE,
154 init_status_request, tls_parse_ctos_status_request,
155 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
156 tls_construct_ctos_status_request, final_status_request
159 #ifndef OPENSSL_NO_NEXTPROTONEG
161 TLSEXT_TYPE_next_proto_neg,
162 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
163 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
164 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
169 * Must appear in this list after server_name so that finalisation
170 * happens after server_name callbacks
172 TLSEXT_TYPE_application_layer_protocol_negotiation,
173 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
174 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
175 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
176 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
178 #ifndef OPENSSL_NO_SRTP
180 TLSEXT_TYPE_use_srtp,
181 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
182 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY,
183 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
184 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
188 TLSEXT_TYPE_encrypt_then_mac,
189 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
190 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
191 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
193 #ifndef OPENSSL_NO_CT
195 TLSEXT_TYPE_signed_certificate_timestamp,
196 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
197 | EXT_TLS1_3_CERTIFICATE,
200 * No server side support for this, but can be provided by a custom
201 * extension. This is an exception to the rule that custom extensions
202 * cannot override built in ones.
204 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
208 TLSEXT_TYPE_extended_master_secret,
209 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
210 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
211 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
214 TLSEXT_TYPE_supported_versions,
215 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
217 /* Processed inline as part of version selection */
218 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
222 * Must be in this list after supported_groups. We need that to have
223 * been parsed before we do this one.
225 TLSEXT_TYPE_key_share,
226 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO
227 | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY
229 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
230 tls_construct_stoc_key_share, tls_construct_ctos_key_share, NULL
234 * Special unsolicited ServerHello extension only used when
235 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
237 TLSEXT_TYPE_cryptopro_bug,
238 EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
239 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
242 /* Last in the list because it must be added as the last extension */
246 /* We send this, but don't read it */
247 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
252 * Verify whether we are allowed to use the extension |type| in the current
253 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
254 * indicate the extension is not allowed. If returning 1 then |*found| is set to
255 * 1 if we found a definition for the extension, and |*idx| is set to its index
257 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
258 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
259 RAW_EXTENSION **found)
262 size_t builtin_num = OSSL_NELEM(ext_defs);
263 const EXTENSION_DEFINITION *thisext;
265 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
266 if (type == thisext->type) {
267 /* Check we're allowed to use this extension in this context */
268 if ((context & thisext->context) == 0)
271 if (SSL_IS_DTLS(s)) {
272 if ((thisext->context & EXT_TLS_ONLY) != 0)
274 } else if ((thisext->context & EXT_DTLS_ONLY) != 0) {
278 *found = &rawexlist[i];
283 if ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) == 0) {
285 * Custom extensions only apply to <=TLS1.2. This extension is unknown
286 * in this context - we allow it
292 /* Check the custom extensions */
294 for (i = builtin_num; i < builtin_num + meths->meths_count; i++) {
295 if (meths->meths[i - builtin_num].ext_type == type) {
296 *found = &rawexlist[i];
302 /* Unknown extension. We allow it */
308 * Check whether the context defined for an extension |extctx| means whether
309 * the extension is relevant for the current context |thisctx| or not. Returns
310 * 1 if the extension is relevant for this context, and 0 otherwise
312 static int extension_is_relevant(SSL *s, unsigned int extctx,
313 unsigned int thisctx)
316 && (extctx & EXT_TLS_IMPLEMENTATION_ONLY) != 0)
317 || (s->version == SSL3_VERSION
318 && (extctx & EXT_SSL3_ALLOWED) == 0)
320 && (extctx & EXT_TLS1_2_AND_BELOW_ONLY) != 0)
321 || (!SSL_IS_TLS13(s) && (extctx & EXT_TLS1_3_ONLY) != 0))
328 * Gather a list of all the extensions from the data in |packet]. |context|
329 * tells us which message this extension is for. The raw extension data is
330 * stored in |*res| on success. In the event of an error the alert type to use
331 * is stored in |*al|. We don't actually process the content of the extensions
332 * yet, except to check their types. This function also runs the initialiser
333 * functions for all known extensions (whether we have collected them or not).
334 * If successful the caller is responsible for freeing the contents of |*res|.
336 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
337 * more than one extension of the same type in a ClientHello or ServerHello.
338 * This function returns 1 if all extensions are unique and we have parsed their
339 * types, and 0 if the extensions contain duplicates, could not be successfully
340 * found, or an internal error occurred. We only check duplicates for
341 * extensions that we know about. We ignore others.
343 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
344 RAW_EXTENSION **res, int *al)
346 PACKET extensions = *packet;
348 custom_ext_methods *exts = NULL;
349 RAW_EXTENSION *raw_extensions = NULL;
350 const EXTENSION_DEFINITION *thisexd;
355 * Initialise server side custom extensions. Client side is done during
356 * construction of extensions for the ClientHello.
358 if ((context & EXT_CLIENT_HELLO) != 0) {
359 exts = &s->cert->srv_ext;
360 custom_ext_init(&s->cert->srv_ext);
361 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
362 exts = &s->cert->cli_ext;
365 raw_extensions = OPENSSL_zalloc((OSSL_NELEM(ext_defs)
366 + (exts != NULL ? exts->meths_count : 0))
367 * sizeof(*raw_extensions));
368 if (raw_extensions == NULL) {
369 *al = SSL_AD_INTERNAL_ERROR;
370 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
374 while (PACKET_remaining(&extensions) > 0) {
377 RAW_EXTENSION *thisex;
379 if (!PACKET_get_net_2(&extensions, &type) ||
380 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
381 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
382 *al = SSL_AD_DECODE_ERROR;
386 * Verify this extension is allowed. We only check duplicates for
387 * extensions that we recognise.
389 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
390 || (thisex != NULL && thisex->present == 1)) {
391 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
392 *al = SSL_AD_ILLEGAL_PARAMETER;
395 if (thisex != NULL) {
396 thisex->data = extension;
403 * Initialise all known extensions relevant to this context, whether we have
406 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
407 if(thisexd->init != NULL && (thisexd->context & context) != 0
408 && extension_is_relevant(s, thisexd->context, context)
409 && !thisexd->init(s, context)) {
410 *al = SSL_AD_INTERNAL_ERROR;
415 *res = raw_extensions;
419 OPENSSL_free(raw_extensions);
424 * Runs the parser for a given extension with index |idx|. |exts| contains the
425 * list of all parsed extensions previously collected by
426 * tls_collect_extensions(). The parser is only run if it is applicable for the
427 * given |context| and the parser has not already been run. Returns 1 on success
428 * or 0 on failure. In the event of a failure |*al| is populated with a suitable
429 * alert code. If an extension is not present this counted as success.
431 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
432 RAW_EXTENSION *exts, int *al)
434 RAW_EXTENSION *currext = &exts[idx];
435 int (*parser)(SSL *s, PACKET *pkt, int *al) = NULL;
437 /* Skip if the extension is not present */
438 if (!currext->present)
441 if (s->tlsext_debug_cb)
442 s->tlsext_debug_cb(s, !s->server, currext->type,
443 PACKET_data(&currext->data),
444 PACKET_remaining(&currext->data),
445 s->tlsext_debug_arg);
447 /* Skip if we've already parsed this extension */
453 if (idx < OSSL_NELEM(ext_defs)) {
454 /* We are handling a built-in extension */
455 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
457 /* Check if extension is defined for our protocol. If not, skip */
458 if (!extension_is_relevant(s, extdef->context, context))
461 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
464 return parser(s, &currext->data, al);
467 * If the parser is NULL we fall through to the custom extension
473 * This is a custom extension. We only allow this if it is a non
474 * resumed session on the server side.
476 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
477 * We're going to need a new mechanism for TLS1.3 to specify which
478 * messages to add the custom extensions to.
480 if ((!s->hit || !s->server)
482 & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
483 && custom_ext_parse(s, s->server, currext->type,
484 PACKET_data(&currext->data),
485 PACKET_remaining(&currext->data),
493 * Parse all remaining extensions that have not yet been parsed. Also calls the
494 * finalisation for all extensions at the end, whether we collected them or not.
495 * Returns 1 for success or 0 for failure. On failure, |*al| is populated with a
496 * suitable alert code.
498 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, int *al)
500 size_t i, numexts = OSSL_NELEM(ext_defs);
501 const EXTENSION_DEFINITION *thisexd;
503 /* Calculate the number of extensions in the extensions list */
504 if ((context & EXT_CLIENT_HELLO) != 0) {
505 numexts += s->cert->srv_ext.meths_count;
506 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
507 numexts += s->cert->cli_ext.meths_count;
510 /* Parse each extension in turn */
511 for (i = 0; i < numexts; i++) {
512 if (!tls_parse_extension(s, i, context, exts, al))
517 * Finalise all known extensions relevant to this context, whether we have
520 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
521 if(thisexd->final != NULL
522 && (thisexd->context & context) != 0
523 && !thisexd->final(s, context, exts[i].present, al))
531 * Construct all the extensions relevant to the current |context| and write
532 * them to |pkt|. Returns 1 on success or 0 on failure. If a failure occurs then
533 * |al| is populated with a suitable alert code. On a failure construction stops
534 * at the first extension to fail to construct.
536 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
540 int addcustom = 0, min_version, max_version = 0, reason, tmpal;
541 const EXTENSION_DEFINITION *thisexd;
544 * Normally if something goes wrong during construction it's an internal
545 * error. We can always override this later.
547 tmpal = SSL_AD_INTERNAL_ERROR;
549 if (!WPACKET_start_sub_packet_u16(pkt)
551 * If extensions are of zero length then we don't even add the
552 * extensions length bytes to a ClientHello/ServerHello in SSLv3
554 || ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
555 && s->version == SSL3_VERSION
556 && !WPACKET_set_flags(pkt,
557 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
558 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
562 if ((context & EXT_CLIENT_HELLO) != 0) {
563 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
565 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
570 /* Add custom extensions first */
571 if ((context & EXT_CLIENT_HELLO) != 0) {
572 custom_ext_init(&s->cert->cli_ext);
574 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
576 * We already initialised the custom extensions during ClientHello
579 * TODO(TLS1.3): We're going to need a new custom extension mechanism
580 * for TLS1.3, so that custom extensions can specify which of the
581 * multiple message they wish to add themselves to.
586 if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) {
587 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
591 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
592 int (*construct)(SSL *s, WPACKET *pkt, int *al);
594 /* Skip if not relevant for our context */
595 if ((thisexd->context & context) == 0)
598 construct = s->server ? thisexd->construct_stoc
599 : thisexd->construct_ctos;
601 /* Check if this extension is defined for our protocol. If not, skip */
603 && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY)
605 || (s->version == SSL3_VERSION
606 && (thisexd->context & EXT_SSL3_ALLOWED) == 0)
608 && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY)
611 && (thisexd->context & EXT_TLS1_3_ONLY) != 0
612 && (context & EXT_CLIENT_HELLO) == 0)
613 || ((thisexd->context & EXT_TLS1_3_ONLY) != 0
614 && (context & EXT_CLIENT_HELLO) != 0
615 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))
616 || construct == NULL)
619 if (!construct(s, pkt, &tmpal))
623 if (!WPACKET_close(pkt)) {
624 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
636 * Built in extension finalisation and initialisation functions. All initialise
637 * or finalise the associated extension type for the given |context|. For
638 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
639 * otherwise. These functions return 1 on success or 0 on failure. In the event
640 * of a failure then |*al| is populated with a suitable error code.
643 static int final_renegotiate(SSL *s, unsigned int context, int sent,
648 * Check if we can connect to a server that doesn't support safe
651 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
652 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
654 *al = SSL_AD_HANDSHAKE_FAILURE;
655 SSLerr(SSL_F_FINAL_RENEGOTIATE,
656 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
663 /* Need RI if renegotiating */
665 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
667 *al = SSL_AD_HANDSHAKE_FAILURE;
668 SSLerr(SSL_F_FINAL_RENEGOTIATE,
669 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
677 static int init_server_name(SSL *s, unsigned int context)
680 s->servername_done = 0;
685 static int final_server_name(SSL *s, unsigned int context, int sent,
688 int ret = SSL_TLSEXT_ERR_NOACK;
689 int altmp = SSL_AD_UNRECOGNIZED_NAME;
691 if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
692 ret = s->ctx->tlsext_servername_callback(s, &altmp,
693 s->ctx->tlsext_servername_arg);
694 else if (s->initial_ctx != NULL
695 && s->initial_ctx->tlsext_servername_callback != 0)
696 ret = s->initial_ctx->tlsext_servername_callback(s, &altmp,
697 s->initial_ctx->tlsext_servername_arg);
700 case SSL_TLSEXT_ERR_ALERT_FATAL:
704 case SSL_TLSEXT_ERR_ALERT_WARNING:
708 case SSL_TLSEXT_ERR_NOACK:
709 s->servername_done = 0;
717 #ifndef OPENSSL_NO_EC
718 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
721 unsigned long alg_k, alg_a;
726 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
727 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
730 * If we are client and using an elliptic curve cryptography cipher
731 * suite, then if server returns an EC point formats lists extension it
732 * must contain uncompressed.
734 if (s->tlsext_ecpointformatlist != NULL
735 && s->tlsext_ecpointformatlist_length > 0
736 && s->session->tlsext_ecpointformatlist != NULL
737 && s->session->tlsext_ecpointformatlist_length > 0
738 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
739 /* we are using an ECC cipher */
741 unsigned char *list = s->session->tlsext_ecpointformatlist;
743 for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++) {
744 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
747 if (i == s->session->tlsext_ecpointformatlist_length) {
748 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
749 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
758 static int init_session_ticket(SSL *s, unsigned int context)
761 s->tlsext_ticket_expected = 0;
766 static int init_status_request(SSL *s, unsigned int context)
769 s->tlsext_status_type = TLSEXT_STATUSTYPE_nothing;
774 static int final_status_request(SSL *s, unsigned int context, int sent,
781 * Ensure we get sensible values passed to tlsext_status_cb in the event
782 * that we don't receive a status message
784 OPENSSL_free(s->tlsext_ocsp_resp);
785 s->tlsext_ocsp_resp = NULL;
786 s->tlsext_ocsp_resplen = 0;
791 #ifndef OPENSSL_NO_NEXTPROTONEG
792 static int init_npn(SSL *s, unsigned int context)
794 s->s3->next_proto_neg_seen = 0;
800 static int init_alpn(SSL *s, unsigned int context)
802 OPENSSL_free(s->s3->alpn_selected);
803 s->s3->alpn_selected = NULL;
805 s->s3->alpn_selected_len = 0;
806 OPENSSL_free(s->s3->alpn_proposed);
807 s->s3->alpn_proposed = NULL;
808 s->s3->alpn_proposed_len = 0;
813 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
815 const unsigned char *selected = NULL;
816 unsigned char selected_len = 0;
821 if (s->ctx->alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
822 int r = s->ctx->alpn_select_cb(s, &selected, &selected_len,
823 s->s3->alpn_proposed,
824 (unsigned int)s->s3->alpn_proposed_len,
825 s->ctx->alpn_select_cb_arg);
827 if (r == SSL_TLSEXT_ERR_OK) {
828 OPENSSL_free(s->s3->alpn_selected);
829 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
830 if (s->s3->alpn_selected == NULL) {
831 *al = SSL_AD_INTERNAL_ERROR;
834 s->s3->alpn_selected_len = selected_len;
835 #ifndef OPENSSL_NO_NEXTPROTONEG
836 /* ALPN takes precedence over NPN. */
837 s->s3->next_proto_neg_seen = 0;
840 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
848 static int init_sig_algs(SSL *s, unsigned int context)
850 /* Clear any signature algorithms extension received */
851 OPENSSL_free(s->s3->tmp.peer_sigalgs);
852 s->s3->tmp.peer_sigalgs = NULL;
857 #ifndef OPENSSL_NO_SRP
858 static int init_srp(SSL *s, unsigned int context)
860 OPENSSL_free(s->srp_ctx.login);
861 s->srp_ctx.login = NULL;
867 static int init_etm(SSL *s, unsigned int context)
869 s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
874 static int init_ems(SSL *s, unsigned int context)
877 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
882 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
884 if (!s->server && s->hit) {
886 * Check extended master secret extension is consistent with
889 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
890 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
891 *al = SSL_AD_HANDSHAKE_FAILURE;
892 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
900 #ifndef OPENSSL_NO_SRTP
901 static int init_srtp(SSL *s, unsigned int context)
904 s->srtp_profile = NULL;