2 * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include "../ssl_locl.h"
11 #include "statem_locl.h"
13 static int final_renegotiate(SSL *s, unsigned int context, int sent,
15 static int init_server_name(SSL *s, unsigned int context);
16 static int final_server_name(SSL *s, unsigned int context, int sent,
19 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
22 static int init_session_ticket(SSL *s, unsigned int context);
23 #ifndef OPENSSL_NO_OCSP
24 static int init_status_request(SSL *s, unsigned int context);
26 #ifndef OPENSSL_NO_NEXTPROTONEG
27 static int init_npn(SSL *s, unsigned int context);
29 static int init_alpn(SSL *s, unsigned int context);
30 static int final_alpn(SSL *s, unsigned int context, int sent, int *al);
31 static int init_sig_algs(SSL *s, unsigned int context);
32 #ifndef OPENSSL_NO_SRP
33 static int init_srp(SSL *s, unsigned int context);
35 static int init_etm(SSL *s, unsigned int context);
36 static int init_ems(SSL *s, unsigned int context);
37 static int final_ems(SSL *s, unsigned int context, int sent, int *al);
38 static int init_psk_kex_modes(SSL *s, unsigned int context);
40 static int final_key_share(SSL *s, unsigned int context, int sent, int *al);
42 #ifndef OPENSSL_NO_SRTP
43 static int init_srtp(SSL *s, unsigned int context);
45 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al);
46 static int final_early_data(SSL *s, unsigned int context, int sent, int *al);
48 /* Structure to define a built-in extension */
49 typedef struct extensions_definition_st {
50 /* The defined type for the extension */
53 * The context that this extension applies to, e.g. what messages and
58 * Initialise extension before parsing. Always called for relevant contexts
59 * even if extension not present
61 int (*init)(SSL *s, unsigned int context);
62 /* Parse extension sent from client to server */
63 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
64 size_t chainidx, int *al);
65 /* Parse extension send from server to client */
66 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
67 size_t chainidx, int *al);
68 /* Construct extension sent from server to client */
69 int (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
70 size_t chainidx, int *al);
71 /* Construct extension sent from client to server */
72 int (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
73 size_t chainidx, int *al);
75 * Finalise extension after parsing. Always called where an extensions was
76 * initialised even if the extension was not present. |sent| is set to 1 if
77 * the extension was seen, or 0 otherwise.
79 int (*final)(SSL *s, unsigned int context, int sent, int *al);
80 } EXTENSION_DEFINITION;
83 * Definitions of all built-in extensions. NOTE: Changes in the number or order
84 * of these extensions should be mirrored with equivalent changes to the
85 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
86 * Each extension has an initialiser, a client and
87 * server side parser and a finaliser. The initialiser is called (if the
88 * extension is relevant to the given context) even if we did not see the
89 * extension in the message that we received. The parser functions are only
90 * called if we see the extension in the message. The finalisers are always
91 * called if the initialiser was called.
92 * There are also server and client side constructor functions which are always
93 * called during message construction if the extension is relevant for the
95 * The initialisation, parsing, finalisation and construction functions are
96 * always called in the order defined in this list. Some extensions may depend
97 * on others having been processed first, so the order of this list is
99 * The extension context is defined by a series of flags which specify which
100 * messages the extension is relevant to. These flags also specify whether the
101 * extension is relevant to a particular protocol or protocol version.
103 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
105 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
106 static const EXTENSION_DEFINITION ext_defs[] = {
108 TLSEXT_TYPE_renegotiate,
109 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_SSL3_ALLOWED
110 | EXT_TLS1_2_AND_BELOW_ONLY,
111 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
112 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
116 TLSEXT_TYPE_server_name,
117 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
118 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
120 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
121 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
124 #ifndef OPENSSL_NO_SRP
127 EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
128 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
134 TLSEXT_TYPE_early_data_info,
135 EXT_TLS1_3_NEW_SESSION_TICKET,
136 NULL, NULL, tls_parse_stoc_early_data_info,
137 tls_construct_stoc_early_data_info, NULL, NULL
139 #ifndef OPENSSL_NO_EC
141 TLSEXT_TYPE_ec_point_formats,
142 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
143 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
144 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
148 TLSEXT_TYPE_supported_groups,
149 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
150 NULL, tls_parse_ctos_supported_groups, NULL,
151 NULL /* TODO(TLS1.3): Need to add this */,
152 tls_construct_ctos_supported_groups, NULL
159 TLSEXT_TYPE_session_ticket,
160 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
161 init_session_ticket, tls_parse_ctos_session_ticket,
162 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
163 tls_construct_ctos_session_ticket, NULL
166 TLSEXT_TYPE_signature_algorithms,
168 init_sig_algs, tls_parse_ctos_sig_algs, NULL, NULL,
169 tls_construct_ctos_sig_algs, final_sig_algs
171 #ifndef OPENSSL_NO_OCSP
173 TLSEXT_TYPE_status_request,
174 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
175 | EXT_TLS1_3_CERTIFICATE,
176 init_status_request, tls_parse_ctos_status_request,
177 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
178 tls_construct_ctos_status_request, NULL
183 #ifndef OPENSSL_NO_NEXTPROTONEG
185 TLSEXT_TYPE_next_proto_neg,
186 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
187 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
188 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
195 * Must appear in this list after server_name so that finalisation
196 * happens after server_name callbacks
198 TLSEXT_TYPE_application_layer_protocol_negotiation,
199 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
200 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
201 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
202 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
204 #ifndef OPENSSL_NO_SRTP
206 TLSEXT_TYPE_use_srtp,
207 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
208 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY,
209 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
210 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
216 TLSEXT_TYPE_encrypt_then_mac,
217 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY | EXT_SSL3_ALLOWED,
218 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
219 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
221 #ifndef OPENSSL_NO_CT
223 TLSEXT_TYPE_signed_certificate_timestamp,
224 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
225 | EXT_TLS1_3_CERTIFICATE,
228 * No server side support for this, but can be provided by a custom
229 * extension. This is an exception to the rule that custom extensions
230 * cannot override built in ones.
232 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
238 TLSEXT_TYPE_extended_master_secret,
239 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
240 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
241 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
244 TLSEXT_TYPE_supported_versions,
245 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
247 /* Processed inline as part of version selection */
248 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
251 TLSEXT_TYPE_psk_kex_modes,
252 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
253 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
254 tls_construct_ctos_psk_kex_modes, NULL
256 #ifndef OPENSSL_NO_EC
259 * Must be in this list after supported_groups. We need that to have
260 * been parsed before we do this one.
262 TLSEXT_TYPE_key_share,
263 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO
264 | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY
266 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
267 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
273 * Special unsolicited ServerHello extension only used when
274 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
276 TLSEXT_TYPE_cryptopro_bug,
277 EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
278 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
281 TLSEXT_TYPE_early_data,
282 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
283 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data,
284 tls_construct_stoc_early_data, tls_construct_ctos_early_data,
288 /* Must be immediately before pre_shared_key */
289 /* TODO(TLS1.3): Fix me */
293 /* We send this, but don't read it */
294 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
297 /* Required by the TLSv1.3 spec to always be the last extension */
299 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO | EXT_TLS_IMPLEMENTATION_ONLY
301 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
302 tls_construct_ctos_psk, NULL
307 * Verify whether we are allowed to use the extension |type| in the current
308 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
309 * indicate the extension is not allowed. If returning 1 then |*found| is set to
310 * 1 if we found a definition for the extension, and |*idx| is set to its index
312 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
313 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
314 RAW_EXTENSION **found)
317 size_t builtin_num = OSSL_NELEM(ext_defs);
318 const EXTENSION_DEFINITION *thisext;
320 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
321 if (type == thisext->type) {
322 /* Check we're allowed to use this extension in this context */
323 if ((context & thisext->context) == 0)
326 if (SSL_IS_DTLS(s)) {
327 if ((thisext->context & EXT_TLS_ONLY) != 0)
329 } else if ((thisext->context & EXT_DTLS_ONLY) != 0) {
333 *found = &rawexlist[i];
338 if ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) == 0) {
340 * Custom extensions only apply to <=TLS1.2. This extension is unknown
341 * in this context - we allow it
347 /* Check the custom extensions */
349 for (i = builtin_num; i < builtin_num + meths->meths_count; i++) {
350 if (meths->meths[i - builtin_num].ext_type == type) {
351 *found = &rawexlist[i];
357 /* Unknown extension. We allow it */
363 * Check whether the context defined for an extension |extctx| means whether
364 * the extension is relevant for the current context |thisctx| or not. Returns
365 * 1 if the extension is relevant for this context, and 0 otherwise
367 static int extension_is_relevant(SSL *s, unsigned int extctx,
368 unsigned int thisctx)
371 && (extctx & EXT_TLS_IMPLEMENTATION_ONLY) != 0)
372 || (s->version == SSL3_VERSION
373 && (extctx & EXT_SSL3_ALLOWED) == 0)
375 && (extctx & EXT_TLS1_2_AND_BELOW_ONLY) != 0)
376 || (!SSL_IS_TLS13(s) && (extctx & EXT_TLS1_3_ONLY) != 0))
383 * Gather a list of all the extensions from the data in |packet]. |context|
384 * tells us which message this extension is for. The raw extension data is
385 * stored in |*res| on success. In the event of an error the alert type to use
386 * is stored in |*al|. We don't actually process the content of the extensions
387 * yet, except to check their types. This function also runs the initialiser
388 * functions for all known extensions (whether we have collected them or not).
389 * If successful the caller is responsible for freeing the contents of |*res|.
391 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
392 * more than one extension of the same type in a ClientHello or ServerHello.
393 * This function returns 1 if all extensions are unique and we have parsed their
394 * types, and 0 if the extensions contain duplicates, could not be successfully
395 * found, or an internal error occurred. We only check duplicates for
396 * extensions that we know about. We ignore others.
398 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
399 RAW_EXTENSION **res, int *al, size_t *len)
401 PACKET extensions = *packet;
404 custom_ext_methods *exts = NULL;
405 RAW_EXTENSION *raw_extensions = NULL;
406 const EXTENSION_DEFINITION *thisexd;
411 * Initialise server side custom extensions. Client side is done during
412 * construction of extensions for the ClientHello.
414 if ((context & EXT_CLIENT_HELLO) != 0) {
415 exts = &s->cert->srv_ext;
416 custom_ext_init(&s->cert->srv_ext);
417 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
418 exts = &s->cert->cli_ext;
421 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
422 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
423 if (raw_extensions == NULL) {
424 *al = SSL_AD_INTERNAL_ERROR;
425 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
429 while (PACKET_remaining(&extensions) > 0) {
432 RAW_EXTENSION *thisex;
434 if (!PACKET_get_net_2(&extensions, &type) ||
435 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
436 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
437 *al = SSL_AD_DECODE_ERROR;
441 * Verify this extension is allowed. We only check duplicates for
442 * extensions that we recognise.
444 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
445 || (thisex != NULL && thisex->present == 1)) {
446 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
447 *al = SSL_AD_ILLEGAL_PARAMETER;
450 if (thisex != NULL) {
451 thisex->data = extension;
458 * Initialise all known extensions relevant to this context, whether we have
461 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
462 if(thisexd->init != NULL && (thisexd->context & context) != 0
463 && extension_is_relevant(s, thisexd->context, context)
464 && !thisexd->init(s, context)) {
465 *al = SSL_AD_INTERNAL_ERROR;
470 *res = raw_extensions;
476 OPENSSL_free(raw_extensions);
481 * Runs the parser for a given extension with index |idx|. |exts| contains the
482 * list of all parsed extensions previously collected by
483 * tls_collect_extensions(). The parser is only run if it is applicable for the
484 * given |context| and the parser has not already been run. If this is for a
485 * Certificate message, then we also provide the parser with the relevant
486 * Certificate |x| and its position in the |chainidx| with 0 being the first
487 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
488 * |*al| is populated with a suitable alert code. If an extension is not present
489 * this counted as success.
491 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
492 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
494 RAW_EXTENSION *currext = &exts[idx];
495 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
496 size_t chainidx, int *al) = NULL;
498 /* Skip if the extension is not present */
499 if (!currext->present)
503 s->ext.debug_cb(s, !s->server, currext->type,
504 PACKET_data(&currext->data),
505 PACKET_remaining(&currext->data),
508 /* Skip if we've already parsed this extension */
514 if (idx < OSSL_NELEM(ext_defs)) {
515 /* We are handling a built-in extension */
516 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
518 /* Check if extension is defined for our protocol. If not, skip */
519 if (!extension_is_relevant(s, extdef->context, context))
522 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
525 return parser(s, &currext->data, context, x, chainidx, al);
528 * If the parser is NULL we fall through to the custom extension
534 * This is a custom extension. We only allow this if it is a non
535 * resumed session on the server side.
537 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
538 * We're going to need a new mechanism for TLS1.3 to specify which
539 * messages to add the custom extensions to.
541 if ((!s->hit || !s->server)
543 & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
544 && custom_ext_parse(s, s->server, currext->type,
545 PACKET_data(&currext->data),
546 PACKET_remaining(&currext->data),
554 * Parse all remaining extensions that have not yet been parsed. Also calls the
555 * finalisation for all extensions at the end, whether we collected them or not.
556 * Returns 1 for success or 0 for failure. If we are working on a Certificate
557 * message then we also pass the Certificate |x| and its position in the
558 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
559 * populated with a suitable alert code.
561 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
562 size_t chainidx, int *al)
564 size_t i, numexts = OSSL_NELEM(ext_defs);
565 const EXTENSION_DEFINITION *thisexd;
567 /* Calculate the number of extensions in the extensions list */
568 if ((context & EXT_CLIENT_HELLO) != 0) {
569 numexts += s->cert->srv_ext.meths_count;
570 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
571 numexts += s->cert->cli_ext.meths_count;
574 /* Parse each extension in turn */
575 for (i = 0; i < numexts; i++) {
576 if (!tls_parse_extension(s, i, context, exts, x, chainidx, al))
581 * Finalise all known extensions relevant to this context, whether we have
584 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
585 if(thisexd->final != NULL
586 && (thisexd->context & context) != 0
587 && !thisexd->final(s, context, exts[i].present, al))
595 * Construct all the extensions relevant to the current |context| and write
596 * them to |pkt|. If this is an extension for a Certificate in a Certificate
597 * message, then |x| will be set to the Certificate we are handling, and
598 * |chainidx| will indicate the position in the chainidx we are processing (with
599 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
600 * failure occurs then |al| is populated with a suitable alert code. On a
601 * failure construction stops at the first extension to fail to construct.
603 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
604 X509 *x, size_t chainidx, int *al)
607 int addcustom = 0, min_version, max_version = 0, reason, tmpal;
608 const EXTENSION_DEFINITION *thisexd;
611 * Normally if something goes wrong during construction it's an internal
612 * error. We can always override this later.
614 tmpal = SSL_AD_INTERNAL_ERROR;
616 if (!WPACKET_start_sub_packet_u16(pkt)
618 * If extensions are of zero length then we don't even add the
619 * extensions length bytes to a ClientHello/ServerHello in SSLv3
621 || ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
622 && s->version == SSL3_VERSION
623 && !WPACKET_set_flags(pkt,
624 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
625 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
629 if ((context & EXT_CLIENT_HELLO) != 0) {
630 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
632 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
637 /* Add custom extensions first */
638 if ((context & EXT_CLIENT_HELLO) != 0) {
639 custom_ext_init(&s->cert->cli_ext);
641 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
643 * We already initialised the custom extensions during ClientHello
646 * TODO(TLS1.3): We're going to need a new custom extension mechanism
647 * for TLS1.3, so that custom extensions can specify which of the
648 * multiple message they wish to add themselves to.
653 if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) {
654 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
658 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
659 int (*construct)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
660 size_t chainidx, int *al);
662 /* Skip if not relevant for our context */
663 if ((thisexd->context & context) == 0)
666 construct = s->server ? thisexd->construct_stoc
667 : thisexd->construct_ctos;
669 /* Check if this extension is defined for our protocol. If not, skip */
671 && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY)
673 || (s->version == SSL3_VERSION
674 && (thisexd->context & EXT_SSL3_ALLOWED) == 0)
676 && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY)
679 && (thisexd->context & EXT_TLS1_3_ONLY) != 0
680 && (context & EXT_CLIENT_HELLO) == 0)
681 || ((thisexd->context & EXT_TLS1_3_ONLY) != 0
682 && (context & EXT_CLIENT_HELLO) != 0
683 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))
684 || construct == NULL)
687 if (!construct(s, pkt, context, x, chainidx, &tmpal))
691 if (!WPACKET_close(pkt)) {
692 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
704 * Built in extension finalisation and initialisation functions. All initialise
705 * or finalise the associated extension type for the given |context|. For
706 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
707 * otherwise. These functions return 1 on success or 0 on failure. In the event
708 * of a failure then |*al| is populated with a suitable error code.
711 static int final_renegotiate(SSL *s, unsigned int context, int sent,
716 * Check if we can connect to a server that doesn't support safe
719 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
720 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
722 *al = SSL_AD_HANDSHAKE_FAILURE;
723 SSLerr(SSL_F_FINAL_RENEGOTIATE,
724 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
731 /* Need RI if renegotiating */
733 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
735 *al = SSL_AD_HANDSHAKE_FAILURE;
736 SSLerr(SSL_F_FINAL_RENEGOTIATE,
737 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
745 static int init_server_name(SSL *s, unsigned int context)
748 s->servername_done = 0;
753 static int final_server_name(SSL *s, unsigned int context, int sent,
756 int ret = SSL_TLSEXT_ERR_NOACK;
757 int altmp = SSL_AD_UNRECOGNIZED_NAME;
759 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
760 ret = s->ctx->ext.servername_cb(s, &altmp,
761 s->ctx->ext.servername_arg);
762 else if (s->session_ctx != NULL
763 && s->session_ctx->ext.servername_cb != 0)
764 ret = s->session_ctx->ext.servername_cb(s, &altmp,
765 s->session_ctx->ext.servername_arg);
768 case SSL_TLSEXT_ERR_ALERT_FATAL:
772 case SSL_TLSEXT_ERR_ALERT_WARNING:
776 case SSL_TLSEXT_ERR_NOACK:
777 s->servername_done = 0;
785 #ifndef OPENSSL_NO_EC
786 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
789 unsigned long alg_k, alg_a;
794 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
795 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
798 * If we are client and using an elliptic curve cryptography cipher
799 * suite, then if server returns an EC point formats lists extension it
800 * must contain uncompressed.
802 if (s->ext.ecpointformats != NULL
803 && s->ext.ecpointformats_len > 0
804 && s->session->ext.ecpointformats != NULL
805 && s->session->ext.ecpointformats_len > 0
806 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
807 /* we are using an ECC cipher */
809 unsigned char *list = s->session->ext.ecpointformats;
811 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
812 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
815 if (i == s->session->ext.ecpointformats_len) {
816 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
817 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
826 static int init_session_ticket(SSL *s, unsigned int context)
829 s->ext.ticket_expected = 0;
834 #ifndef OPENSSL_NO_OCSP
835 static int init_status_request(SSL *s, unsigned int context)
838 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
841 * Ensure we get sensible values passed to tlsext_status_cb in the event
842 * that we don't receive a status message
844 OPENSSL_free(s->ext.ocsp.resp);
845 s->ext.ocsp.resp = NULL;
846 s->ext.ocsp.resp_len = 0;
853 #ifndef OPENSSL_NO_NEXTPROTONEG
854 static int init_npn(SSL *s, unsigned int context)
862 static int init_alpn(SSL *s, unsigned int context)
864 OPENSSL_free(s->s3->alpn_selected);
865 s->s3->alpn_selected = NULL;
867 s->s3->alpn_selected_len = 0;
868 OPENSSL_free(s->s3->alpn_proposed);
869 s->s3->alpn_proposed = NULL;
870 s->s3->alpn_proposed_len = 0;
875 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
877 const unsigned char *selected = NULL;
878 unsigned char selected_len = 0;
883 if (s->ctx->ext.alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
884 int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len,
885 s->s3->alpn_proposed,
886 (unsigned int)s->s3->alpn_proposed_len,
887 s->ctx->ext.alpn_select_cb_arg);
889 if (r == SSL_TLSEXT_ERR_OK) {
890 OPENSSL_free(s->s3->alpn_selected);
891 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
892 if (s->s3->alpn_selected == NULL) {
893 *al = SSL_AD_INTERNAL_ERROR;
896 s->s3->alpn_selected_len = selected_len;
897 #ifndef OPENSSL_NO_NEXTPROTONEG
898 /* ALPN takes precedence over NPN. */
902 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
910 static int init_sig_algs(SSL *s, unsigned int context)
912 /* Clear any signature algorithms extension received */
913 OPENSSL_free(s->s3->tmp.peer_sigalgs);
914 s->s3->tmp.peer_sigalgs = NULL;
919 #ifndef OPENSSL_NO_SRP
920 static int init_srp(SSL *s, unsigned int context)
922 OPENSSL_free(s->srp_ctx.login);
923 s->srp_ctx.login = NULL;
929 static int init_etm(SSL *s, unsigned int context)
936 static int init_ems(SSL *s, unsigned int context)
939 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
944 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
946 if (!s->server && s->hit) {
948 * Check extended master secret extension is consistent with
951 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
952 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
953 *al = SSL_AD_HANDSHAKE_FAILURE;
954 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
962 #ifndef OPENSSL_NO_SRTP
963 static int init_srtp(SSL *s, unsigned int context)
966 s->srtp_profile = NULL;
972 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
974 if (!sent && SSL_IS_TLS13(s)) {
975 *al = TLS13_AD_MISSING_EXTENSION;
976 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
983 #ifndef OPENSSL_NO_EC
984 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
986 if (!SSL_IS_TLS13(s))
993 * we have no key_share
995 * (we are not resuming
996 * OR the kex_mode doesn't allow non key_share resumes)
1003 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
1004 /* Nothing left we can do - just fail */
1005 *al = SSL_AD_HANDSHAKE_FAILURE;
1006 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1013 * we have no key_share
1016 * we didn't already send a HelloRetryRequest
1018 * the client sent a key_share extension
1020 * (we are not resuming
1021 * OR the kex_mode allows key_share resumes)
1023 * a shared group exists
1025 * send a HelloRetryRequest
1027 * we are not resuming
1029 * the kex_mode doesn't allow non key_share resumes
1033 if (s->server && s->s3->peer_tmp == NULL) {
1034 /* No suitable share */
1035 if (s->hello_retry_request == 0 && sent
1037 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1039 const unsigned char *pcurves, *pcurvestmp, *clntcurves;
1040 size_t num_curves, clnt_num_curves, i;
1041 unsigned int group_id = 0;
1043 /* Check if a shared group exists */
1045 /* Get the clients list of supported groups. */
1046 if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
1047 *al = SSL_AD_INTERNAL_ERROR;
1048 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1052 /* Get our list of available groups */
1053 if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
1054 *al = SSL_AD_INTERNAL_ERROR;
1055 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1059 /* Find the first group we allow that is also in client's list */
1060 for (i = 0, pcurvestmp = pcurves; i < num_curves;
1061 i++, pcurvestmp += 2) {
1062 group_id = bytestogroup(pcurvestmp);
1064 if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1))
1068 if (i < num_curves) {
1069 /* A shared group exists so send a HelloRetryRequest */
1070 s->s3->group_id = group_id;
1071 s->hello_retry_request = 1;
1076 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1077 /* Nothing left we can do - just fail */
1078 *al = SSL_AD_HANDSHAKE_FAILURE;
1079 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1084 /* We have a key_share so don't send any more HelloRetryRequest messages */
1086 s->hello_retry_request = 0;
1089 * For a client side resumption with no key_share we need to generate
1090 * the handshake secret (otherwise this is done during key_share
1093 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
1094 *al = SSL_AD_INTERNAL_ERROR;
1095 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1103 static int init_psk_kex_modes(SSL *s, unsigned int context)
1105 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1109 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1110 size_t binderoffset, const unsigned char *binderin,
1111 unsigned char *binderout,
1112 SSL_SESSION *sess, int sign)
1114 EVP_PKEY *mackey = NULL;
1115 EVP_MD_CTX *mctx = NULL;
1116 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1117 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1118 const char resumption_label[] = "resumption psk binder key";
1119 size_t bindersize, hashsize = EVP_MD_size(md);
1122 /* Generate the early_secret */
1123 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1124 sess->master_key_length,
1125 (unsigned char *)&s->early_secret)) {
1126 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1131 * Create the handshake hash for the binder key...the messages so far are
1134 mctx = EVP_MD_CTX_new();
1136 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1137 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1138 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1142 /* Generate the binder key */
1143 if (!tls13_hkdf_expand(s, md, s->early_secret,
1144 (unsigned char *)resumption_label,
1145 sizeof(resumption_label) - 1, hash, binderkey,
1147 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1151 /* Generate the finished key */
1152 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1153 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1157 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1158 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1163 * Get a hash of the ClientHello up to the start of the binders. If we are
1164 * following a HelloRetryRequest then this includes the hash of the first
1165 * ClientHello and the HelloRetryRequest itself.
1167 if (s->hello_retry_request) {
1171 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
1172 if (hdatalen <= 0) {
1173 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_HANDSHAKE_LENGTH);
1178 * For servers the handshake buffer data will include the second
1179 * ClientHello - which we don't want - so we need to take that bit off.
1182 if (hdatalen < s->init_num + SSL3_HM_HEADER_LENGTH) {
1183 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1186 hdatalen -= s->init_num + SSL3_HM_HEADER_LENGTH;
1189 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1190 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1195 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1196 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1197 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1201 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1202 if (mackey == NULL) {
1203 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1208 binderout = tmpbinder;
1210 bindersize = hashsize;
1211 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1212 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1213 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1214 || bindersize != hashsize) {
1215 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1222 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1223 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1227 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1228 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1229 EVP_PKEY_free(mackey);
1230 EVP_MD_CTX_free(mctx);
1235 static int final_early_data(SSL *s, unsigned int context, int sent, int *al)
1237 if (!s->server || !sent)
1240 if (s->max_early_data == 0
1242 || s->session->ext.tick_identity != 0
1243 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
1244 || !s->ext.early_data_ok
1245 || s->hello_retry_request) {
1246 s->ext.early_data = SSL_EARLY_DATA_REJECTED;
1248 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;
1250 if (!tls13_change_cipher_state(s,
1251 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) {
1252 *al = SSL_AD_INTERNAL_ERROR;