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_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 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;
349 custom_ext_methods *exts = NULL;
350 RAW_EXTENSION *raw_extensions = NULL;
351 EXTENSION_DEFINITION *thisexd;
354 * Initialise server side custom extensions. Client side is done during
355 * construction of extensions for the ClientHello.
357 if ((context & EXT_CLIENT_HELLO) != 0) {
358 exts = &s->cert->srv_ext;
359 custom_ext_init(&s->cert->srv_ext);
360 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
361 exts = &s->cert->cli_ext;
364 raw_extensions = OPENSSL_zalloc((OSSL_NELEM(ext_defs)
365 + (exts != NULL ? exts->meths_count : 0))
366 * sizeof(*raw_extensions));
367 if (raw_extensions == NULL) {
368 *al = SSL_AD_INTERNAL_ERROR;
369 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
373 while (PACKET_remaining(&extensions) > 0) {
376 RAW_EXTENSION *thisex;
378 if (!PACKET_get_net_2(&extensions, &type) ||
379 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
380 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
381 *al = SSL_AD_DECODE_ERROR;
385 * Verify this extension is allowed. We only check duplicates for
386 * extensions that we recognise.
388 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
389 || (thisex != NULL && thisex->present == 1)) {
390 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
391 *al = SSL_AD_ILLEGAL_PARAMETER;
394 if (thisex != NULL) {
395 thisex->data = extension;
402 * Initialise all known extensions relevant to this context, whether we have
405 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
406 if(thisexd->init != NULL && (thisexd->context & context) != 0
407 && extension_is_relevant(s, thisexd->context, context)
408 && !thisexd->init(s, context)) {
409 *al = SSL_AD_INTERNAL_ERROR;
414 *res = raw_extensions;
418 OPENSSL_free(raw_extensions);
423 * Runs the parser for a given extension with index |idx|. |exts| contains the
424 * list of all parsed extensions previously collected by
425 * tls_collect_extensions(). The parser is only run if it is applicable for the
426 * given |context| and the parser has not already been run. Returns 1 on success
427 * or 0 on failure. In the event of a failure |*al| is populated with a suitable
428 * alert code. If an extension is not present this counted as success.
430 int tls_parse_extension(SSL *s, unsigned int idx, int context,
431 RAW_EXTENSION *exts, int *al)
433 RAW_EXTENSION *currext = &exts[idx];
434 int (*parser)(SSL *s, PACKET *pkt, int *al) = NULL;
436 /* Skip if the extension is not present */
437 if (!currext->present)
440 if (s->tlsext_debug_cb)
441 s->tlsext_debug_cb(s, !s->server, currext->type,
442 PACKET_data(&currext->data),
443 PACKET_remaining(&currext->data),
444 s->tlsext_debug_arg);
446 /* Skip if we've already parsed this extension */
452 if (idx < OSSL_NELEM(ext_defs)) {
453 /* We are handling a built-in extension */
454 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
456 /* Check if extension is defined for our protocol. If not, skip */
457 if (!extension_is_relevant(s, extdef->context, context))
460 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
463 return parser(s, &currext->data, al);
466 * If the parser is NULL we fall through to the custom extension
472 * This is a custom extension. We only allow this if it is a non
473 * resumed session on the server side.
475 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
476 * We're going to need a new mechanism for TLS1.3 to specify which
477 * messages to add the custom extensions to.
479 if ((!s->hit || !s->server)
481 & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
482 && custom_ext_parse(s, s->server, currext->type,
483 PACKET_data(&currext->data),
484 PACKET_remaining(&currext->data),
492 * Parse all remaining extensions that have not yet been parsed. Also calls the
493 * finalisation for all extensions at the end, whether we collected them or not.
494 * Returns 1 for success or 0 for failure. On failure, |*al| is populated with a
495 * suitable alert code.
497 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, int *al)
499 size_t i, numexts = OSSL_NELEM(ext_defs);
500 EXTENSION_DEFINITION *thisexd;
502 /* Calculate the number of extensions in the extensions list */
503 if ((context & EXT_CLIENT_HELLO) != 0) {
504 numexts += s->cert->srv_ext.meths_count;
505 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
506 numexts += s->cert->cli_ext.meths_count;
509 /* Parse each extension in turn */
510 for (i = 0; i < numexts; i++) {
511 if (!tls_parse_extension(s, loop, context, exts, al))
516 * Finalise all known extensions relevant to this context, whether we have
519 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
520 if(thisexd->final != NULL
521 && (thisexd->context & context) != 0
522 && !thisexd->final(s, context, exts[i].present, al))
530 * Construct all the extensions relevant to the current |context| and write
531 * them to |pkt|. Returns 1 on success or 0 on failure. If a failure occurs then
532 * |al| is populated with a suitable alert code. On a failure construction stops
533 * at the first extension to fail to construct.
535 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
539 int addcustom = 0, min_version, max_version = 0, reason, tmpal;
540 EXTENSION_DEFINITION *thisexd;
543 * Normally if something goes wrong during construction it's an internal
544 * error. We can always override this later.
546 tmpal = SSL_AD_INTERNAL_ERROR;
548 if (!WPACKET_start_sub_packet_u16(pkt)
550 * If extensions are of zero length then we don't even add the
551 * extensions length bytes to a ClientHello/ServerHello in SSLv3
553 || ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
554 && s->version == SSL3_VERSION
555 && !WPACKET_set_flags(pkt,
556 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
557 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
561 if ((context & EXT_CLIENT_HELLO) != 0) {
562 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
564 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
569 /* Add custom extensions first */
570 if ((context & EXT_CLIENT_HELLO) != 0) {
571 custom_ext_init(&s->cert->cli_ext);
573 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
575 * We already initialised the custom extensions during ClientHello
578 * TODO(TLS1.3): We're going to need a new custom extension mechanism
579 * for TLS1.3, so that custom extensions can specify which of the
580 * multiple message they wish to add themselves to.
585 if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) {
586 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
590 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
591 int (*construct)(SSL *s, WPACKET *pkt, int *al);
593 /* Skip if not relevant for our context */
594 if ((ext_defs[loop].context & context) == 0)
597 construct = s->server ? thisexd->construct_stoc
598 : thisexd->construct_ctos;
600 /* Check if this extension is defined for our protocol. If not, skip */
602 && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY)
604 || (s->version == SSL3_VERSION
605 && (thisexd->context & EXT_SSL3_ALLOWED) == 0)
607 && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY)
610 && (thisexd->context & EXT_TLS1_3_ONLY) != 0
611 && (context & EXT_CLIENT_HELLO) == 0)
612 || ((thisexd->context & EXT_TLS1_3_ONLY) != 0
613 && (context & EXT_CLIENT_HELLO) != 0
614 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))
615 || construct == NULL)
618 if (!construct(s, pkt, &tmpal))
622 if (!WPACKET_close(pkt)) {
623 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
635 * Built in extension finalisation and initialisation functions. All initialise
636 * or finalise the associated extension type for the given |context|. For
637 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
638 * otherwise. These functions return 1 on success or 0 on failure. In the event
639 * of a failure then |*al| is populated with a suitable error code.
642 static int final_renegotiate(SSL *s, unsigned int context, int sent,
647 * Check if we can connect to a server that doesn't support safe
650 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
651 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
653 *al = SSL_AD_HANDSHAKE_FAILURE;
654 SSLerr(SSL_F_TLS_EXT_FINAL_RENEGOTIATE,
655 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
662 /* Need RI if renegotiating */
664 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
666 *al = SSL_AD_HANDSHAKE_FAILURE;
667 SSLerr(SSL_F_TLS_EXT_FINAL_RENEGOTIATE,
668 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
676 static int init_server_name(SSL *s, unsigned int context)
679 s->servername_done = 0;
684 static int final_server_name(SSL *s, unsigned int context, int sent,
687 int ret = SSL_TLSEXT_ERR_NOACK;
688 int altmp = SSL_AD_UNRECOGNIZED_NAME;
690 if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
691 ret = s->ctx->tlsext_servername_callback(s, &altmp,
692 s->ctx->tlsext_servername_arg);
693 else if (s->initial_ctx != NULL
694 && s->initial_ctx->tlsext_servername_callback != 0)
695 ret = s->initial_ctx->tlsext_servername_callback(s, &altmp,
696 s->initial_ctx->tlsext_servername_arg);
699 case SSL_TLSEXT_ERR_ALERT_FATAL:
703 case SSL_TLSEXT_ERR_ALERT_WARNING:
707 case SSL_TLSEXT_ERR_NOACK:
708 s->servername_done = 0;
716 #ifndef OPENSSL_NO_EC
717 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
720 unsigned long alg_k, alg_a;
725 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
726 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
729 * If we are client and using an elliptic curve cryptography cipher
730 * suite, then if server returns an EC point formats lists extension it
731 * must contain uncompressed.
733 if (s->tlsext_ecpointformatlist != NULL
734 && s->tlsext_ecpointformatlist_length > 0
735 && s->session->tlsext_ecpointformatlist != NULL
736 && s->session->tlsext_ecpointformatlist_length > 0
737 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
738 /* we are using an ECC cipher */
740 unsigned char *list = s->session->tlsext_ecpointformatlist;
742 for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++) {
743 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
746 if (i == s->session->tlsext_ecpointformatlist_length) {
747 SSLerr(SSL_F_TLS_EXT_FINAL_EC_PT_FORMATS,
748 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
757 static int init_session_ticket(SSL *s, unsigned int context)
760 s->tlsext_ticket_expected = 0;
765 static int init_status_request(SSL *s, unsigned int context)
768 s->tlsext_status_type = -1;
773 static int final_status_request(SSL *s, unsigned int context, int sent,
780 * Ensure we get sensible values passed to tlsext_status_cb in the event
781 * that we don't receive a status message
783 OPENSSL_free(s->tlsext_ocsp_resp);
784 s->tlsext_ocsp_resp = NULL;
785 s->tlsext_ocsp_resplen = 0;
790 #ifndef OPENSSL_NO_NEXTPROTONEG
791 static int init_npn(SSL *s, unsigned int context)
793 s->s3->next_proto_neg_seen = 0;
799 static int init_alpn(SSL *s, unsigned int context)
801 OPENSSL_free(s->s3->alpn_selected);
802 s->s3->alpn_selected = NULL;
804 s->s3->alpn_selected_len = 0;
805 OPENSSL_free(s->s3->alpn_proposed);
806 s->s3->alpn_proposed = NULL;
807 s->s3->alpn_proposed_len = 0;
812 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
814 const unsigned char *selected = NULL;
815 unsigned char selected_len = 0;
820 if (s->ctx->alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
821 int r = s->ctx->alpn_select_cb(s, &selected, &selected_len,
822 s->s3->alpn_proposed,
823 (unsigned int)s->s3->alpn_proposed_len,
824 s->ctx->alpn_select_cb_arg);
826 if (r == SSL_TLSEXT_ERR_OK) {
827 OPENSSL_free(s->s3->alpn_selected);
828 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
829 if (s->s3->alpn_selected == NULL) {
830 *al = SSL_AD_INTERNAL_ERROR;
833 s->s3->alpn_selected_len = selected_len;
834 #ifndef OPENSSL_NO_NEXTPROTONEG
835 /* ALPN takes precedence over NPN. */
836 s->s3->next_proto_neg_seen = 0;
839 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
847 static int init_sig_algs(SSL *s, unsigned int context)
849 /* Clear any signature algorithms extension received */
850 OPENSSL_free(s->s3->tmp.peer_sigalgs);
851 s->s3->tmp.peer_sigalgs = NULL;
856 #ifndef OPENSSL_NO_SRP
857 static int init_srp(SSL *s, unsigned int context)
859 OPENSSL_free(s->srp_ctx.login);
860 s->srp_ctx.login = NULL;
866 static int init_etm(SSL *s, unsigned int context)
868 s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
873 static int init_ems(SSL *s, unsigned int context)
876 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
881 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
883 if (!s->server && s->hit) {
885 * Check extended master secret extension is consistent with
888 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
889 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
890 *al = SSL_AD_HANDSHAKE_FAILURE;
891 SSLerr(SSL_F_TLS_EXT_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
899 #ifndef OPENSSL_NO_SRTP
900 static int init_srtp(SSL *s, unsigned int context)
903 s->srtp_profile = NULL;