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
11 #include "../ssl_locl.h"
12 #include "statem_locl.h"
14 static int final_renegotiate(SSL *s, unsigned int context, int sent,
16 static int init_server_name(SSL *s, unsigned int context);
17 static int final_server_name(SSL *s, unsigned int context, int sent,
20 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
23 static int init_session_ticket(SSL *s, unsigned int context);
24 #ifndef OPENSSL_NO_OCSP
25 static int init_status_request(SSL *s, unsigned int context);
27 #ifndef OPENSSL_NO_NEXTPROTONEG
28 static int init_npn(SSL *s, unsigned int context);
30 static int init_alpn(SSL *s, unsigned int context);
31 static int final_alpn(SSL *s, unsigned int context, int sent, int *al);
32 static int init_sig_algs(SSL *s, unsigned int context);
33 #ifndef OPENSSL_NO_SRP
34 static int init_srp(SSL *s, unsigned int context);
36 static int init_etm(SSL *s, unsigned int context);
37 static int init_ems(SSL *s, unsigned int context);
38 static int final_ems(SSL *s, unsigned int context, int sent, int *al);
39 static int init_psk_kex_modes(SSL *s, unsigned int context);
41 static int final_key_share(SSL *s, unsigned int context, int sent, int *al);
43 #ifndef OPENSSL_NO_SRTP
44 static int init_srtp(SSL *s, unsigned int context);
46 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al);
47 static int final_early_data(SSL *s, unsigned int context, int sent, int *al);
49 /* Structure to define a built-in extension */
50 typedef struct extensions_definition_st {
51 /* The defined type for the extension */
54 * The context that this extension applies to, e.g. what messages and
59 * Initialise extension before parsing. Always called for relevant contexts
60 * even if extension not present
62 int (*init)(SSL *s, unsigned int context);
63 /* Parse extension sent from client to server */
64 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
65 size_t chainidx, int *al);
66 /* Parse extension send from server to client */
67 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
68 size_t chainidx, int *al);
69 /* Construct extension sent from server to client */
70 int (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
71 size_t chainidx, int *al);
72 /* Construct extension sent from client to server */
73 int (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
74 size_t chainidx, int *al);
76 * Finalise extension after parsing. Always called where an extensions was
77 * initialised even if the extension was not present. |sent| is set to 1 if
78 * the extension was seen, or 0 otherwise.
80 int (*final)(SSL *s, unsigned int context, int sent, int *al);
81 } EXTENSION_DEFINITION;
84 * Definitions of all built-in extensions. NOTE: Changes in the number or order
85 * of these extensions should be mirrored with equivalent changes to the
86 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
87 * Each extension has an initialiser, a client and
88 * server side parser and a finaliser. The initialiser is called (if the
89 * extension is relevant to the given context) even if we did not see the
90 * extension in the message that we received. The parser functions are only
91 * called if we see the extension in the message. The finalisers are always
92 * called if the initialiser was called.
93 * There are also server and client side constructor functions which are always
94 * called during message construction if the extension is relevant for the
96 * The initialisation, parsing, finalisation and construction functions are
97 * always called in the order defined in this list. Some extensions may depend
98 * on others having been processed first, so the order of this list is
100 * The extension context is defined by a series of flags which specify which
101 * messages the extension is relevant to. These flags also specify whether the
102 * extension is relevant to a particular protocol or protocol version.
104 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
106 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
107 static const EXTENSION_DEFINITION ext_defs[] = {
109 TLSEXT_TYPE_renegotiate,
110 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_SSL3_ALLOWED
111 | EXT_TLS1_2_AND_BELOW_ONLY,
112 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
113 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
117 TLSEXT_TYPE_server_name,
118 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
119 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
121 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
122 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
125 #ifndef OPENSSL_NO_SRP
128 EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
129 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
134 #ifndef OPENSSL_NO_EC
136 TLSEXT_TYPE_ec_point_formats,
137 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
138 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
139 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
143 TLSEXT_TYPE_supported_groups,
144 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
145 NULL, tls_parse_ctos_supported_groups, NULL,
146 NULL /* TODO(TLS1.3): Need to add this */,
147 tls_construct_ctos_supported_groups, NULL
154 TLSEXT_TYPE_session_ticket,
155 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
156 init_session_ticket, tls_parse_ctos_session_ticket,
157 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
158 tls_construct_ctos_session_ticket, NULL
161 TLSEXT_TYPE_signature_algorithms,
162 EXT_CLIENT_HELLO | EXT_TLS1_3_CERTIFICATE_REQUEST,
163 init_sig_algs, tls_parse_ctos_sig_algs,
164 tls_parse_ctos_sig_algs, tls_construct_ctos_sig_algs,
165 tls_construct_ctos_sig_algs, final_sig_algs
167 #ifndef OPENSSL_NO_OCSP
169 TLSEXT_TYPE_status_request,
170 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
171 | EXT_TLS1_3_CERTIFICATE,
172 init_status_request, tls_parse_ctos_status_request,
173 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
174 tls_construct_ctos_status_request, NULL
179 #ifndef OPENSSL_NO_NEXTPROTONEG
181 TLSEXT_TYPE_next_proto_neg,
182 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
183 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
184 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
191 * Must appear in this list after server_name so that finalisation
192 * happens after server_name callbacks
194 TLSEXT_TYPE_application_layer_protocol_negotiation,
195 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
196 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
197 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
198 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
200 #ifndef OPENSSL_NO_SRTP
202 TLSEXT_TYPE_use_srtp,
203 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
204 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY,
205 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
206 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
212 TLSEXT_TYPE_encrypt_then_mac,
213 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY | EXT_SSL3_ALLOWED,
214 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
215 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
217 #ifndef OPENSSL_NO_CT
219 TLSEXT_TYPE_signed_certificate_timestamp,
220 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
221 | EXT_TLS1_3_CERTIFICATE,
224 * No server side support for this, but can be provided by a custom
225 * extension. This is an exception to the rule that custom extensions
226 * cannot override built in ones.
228 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
234 TLSEXT_TYPE_extended_master_secret,
235 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
236 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
237 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
240 TLSEXT_TYPE_supported_versions,
241 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
243 /* Processed inline as part of version selection */
244 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
247 TLSEXT_TYPE_psk_kex_modes,
248 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
249 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
250 tls_construct_ctos_psk_kex_modes, NULL
252 #ifndef OPENSSL_NO_EC
255 * Must be in this list after supported_groups. We need that to have
256 * been parsed before we do this one.
258 TLSEXT_TYPE_key_share,
259 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO
260 | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY
262 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
263 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
269 EXT_CLIENT_HELLO | EXT_TLS1_3_HELLO_RETRY_REQUEST
270 | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
271 NULL, NULL, tls_parse_stoc_cookie, NULL, tls_construct_ctos_cookie,
276 * Special unsolicited ServerHello extension only used when
277 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
279 TLSEXT_TYPE_cryptopro_bug,
280 EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
281 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
284 TLSEXT_TYPE_early_data,
285 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
286 | EXT_TLS1_3_NEW_SESSION_TICKET,
287 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data,
288 tls_construct_stoc_early_data, tls_construct_ctos_early_data,
292 /* Must be immediately before pre_shared_key */
296 /* We send this, but don't read it */
297 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
300 /* Required by the TLSv1.3 spec to always be the last extension */
302 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO | EXT_TLS_IMPLEMENTATION_ONLY
304 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
305 tls_construct_ctos_psk, NULL
310 * Verify whether we are allowed to use the extension |type| in the current
311 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
312 * indicate the extension is not allowed. If returning 1 then |*found| is set to
313 * 1 if we found a definition for the extension, and |*idx| is set to its index
315 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
316 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
317 RAW_EXTENSION **found)
320 size_t builtin_num = OSSL_NELEM(ext_defs);
321 const EXTENSION_DEFINITION *thisext;
323 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
324 if (type == thisext->type) {
325 /* Check we're allowed to use this extension in this context */
326 if ((context & thisext->context) == 0)
329 if (SSL_IS_DTLS(s)) {
330 if ((thisext->context & EXT_TLS_ONLY) != 0)
332 } else if ((thisext->context & EXT_DTLS_ONLY) != 0) {
336 *found = &rawexlist[i];
341 if ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) == 0) {
343 * Custom extensions only apply to <=TLS1.2. This extension is unknown
344 * in this context - we allow it
350 /* Check the custom extensions */
352 for (i = builtin_num; i < builtin_num + meths->meths_count; i++) {
353 if (meths->meths[i - builtin_num].ext_type == type) {
354 *found = &rawexlist[i];
360 /* Unknown extension. We allow it */
366 * Check whether the context defined for an extension |extctx| means whether
367 * the extension is relevant for the current context |thisctx| or not. Returns
368 * 1 if the extension is relevant for this context, and 0 otherwise
370 static int extension_is_relevant(SSL *s, unsigned int extctx,
371 unsigned int thisctx)
374 && (extctx & EXT_TLS_IMPLEMENTATION_ONLY) != 0)
375 || (s->version == SSL3_VERSION
376 && (extctx & EXT_SSL3_ALLOWED) == 0)
378 && (extctx & EXT_TLS1_2_AND_BELOW_ONLY) != 0)
379 || (!SSL_IS_TLS13(s) && (extctx & EXT_TLS1_3_ONLY) != 0))
386 * Gather a list of all the extensions from the data in |packet]. |context|
387 * tells us which message this extension is for. The raw extension data is
388 * stored in |*res| on success. In the event of an error the alert type to use
389 * is stored in |*al|. We don't actually process the content of the extensions
390 * yet, except to check their types. This function also runs the initialiser
391 * functions for all known extensions (whether we have collected them or not).
392 * If successful the caller is responsible for freeing the contents of |*res|.
394 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
395 * more than one extension of the same type in a ClientHello or ServerHello.
396 * This function returns 1 if all extensions are unique and we have parsed their
397 * types, and 0 if the extensions contain duplicates, could not be successfully
398 * found, or an internal error occurred. We only check duplicates for
399 * extensions that we know about. We ignore others.
401 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
402 RAW_EXTENSION **res, int *al, size_t *len)
404 PACKET extensions = *packet;
407 custom_ext_methods *exts = NULL;
408 RAW_EXTENSION *raw_extensions = NULL;
409 const EXTENSION_DEFINITION *thisexd;
414 * Initialise server side custom extensions. Client side is done during
415 * construction of extensions for the ClientHello.
417 if ((context & EXT_CLIENT_HELLO) != 0) {
418 exts = &s->cert->srv_ext;
419 custom_ext_init(&s->cert->srv_ext);
420 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
421 exts = &s->cert->cli_ext;
424 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
425 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
426 if (raw_extensions == NULL) {
427 *al = SSL_AD_INTERNAL_ERROR;
428 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
432 while (PACKET_remaining(&extensions) > 0) {
435 RAW_EXTENSION *thisex;
437 if (!PACKET_get_net_2(&extensions, &type) ||
438 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
439 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
440 *al = SSL_AD_DECODE_ERROR;
444 * Verify this extension is allowed. We only check duplicates for
445 * extensions that we recognise. We also have a special case for the
446 * PSK extension, which must be the last one in the ClientHello.
448 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
449 || (thisex != NULL && thisex->present == 1)
450 || (type == TLSEXT_TYPE_psk
451 && (context & EXT_CLIENT_HELLO) != 0
452 && PACKET_remaining(&extensions) != 0)) {
453 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
454 *al = SSL_AD_ILLEGAL_PARAMETER;
457 if (thisex != NULL) {
458 thisex->data = extension;
465 * Initialise all known extensions relevant to this context, whether we have
468 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
469 if(thisexd->init != NULL && (thisexd->context & context) != 0
470 && extension_is_relevant(s, thisexd->context, context)
471 && !thisexd->init(s, context)) {
472 *al = SSL_AD_INTERNAL_ERROR;
477 *res = raw_extensions;
483 OPENSSL_free(raw_extensions);
488 * Runs the parser for a given extension with index |idx|. |exts| contains the
489 * list of all parsed extensions previously collected by
490 * tls_collect_extensions(). The parser is only run if it is applicable for the
491 * given |context| and the parser has not already been run. If this is for a
492 * Certificate message, then we also provide the parser with the relevant
493 * Certificate |x| and its position in the |chainidx| with 0 being the first
494 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
495 * |*al| is populated with a suitable alert code. If an extension is not present
496 * this counted as success.
498 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
499 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
501 RAW_EXTENSION *currext = &exts[idx];
502 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
503 size_t chainidx, int *al) = NULL;
505 /* Skip if the extension is not present */
506 if (!currext->present)
510 s->ext.debug_cb(s, !s->server, currext->type,
511 PACKET_data(&currext->data),
512 PACKET_remaining(&currext->data),
515 /* Skip if we've already parsed this extension */
521 if (idx < OSSL_NELEM(ext_defs)) {
522 /* We are handling a built-in extension */
523 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
525 /* Check if extension is defined for our protocol. If not, skip */
526 if (!extension_is_relevant(s, extdef->context, context))
529 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
532 return parser(s, &currext->data, context, x, chainidx, al);
535 * If the parser is NULL we fall through to the custom extension
541 * This is a custom extension. We only allow this if it is a non
542 * resumed session on the server side.
544 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
545 * We're going to need a new mechanism for TLS1.3 to specify which
546 * messages to add the custom extensions to.
548 if ((!s->hit || !s->server)
550 & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
551 && custom_ext_parse(s, s->server, currext->type,
552 PACKET_data(&currext->data),
553 PACKET_remaining(&currext->data),
561 * Parse all remaining extensions that have not yet been parsed. Also calls the
562 * finalisation for all extensions at the end, whether we collected them or not.
563 * Returns 1 for success or 0 for failure. If we are working on a Certificate
564 * message then we also pass the Certificate |x| and its position in the
565 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
566 * populated with a suitable alert code.
568 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
569 size_t chainidx, int *al)
571 size_t i, numexts = OSSL_NELEM(ext_defs);
572 const EXTENSION_DEFINITION *thisexd;
574 /* Calculate the number of extensions in the extensions list */
575 if ((context & EXT_CLIENT_HELLO) != 0) {
576 numexts += s->cert->srv_ext.meths_count;
577 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
578 numexts += s->cert->cli_ext.meths_count;
581 /* Parse each extension in turn */
582 for (i = 0; i < numexts; i++) {
583 if (!tls_parse_extension(s, i, context, exts, x, chainidx, al))
588 * Finalise all known extensions relevant to this context, whether we have
591 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
592 if(thisexd->final != NULL
593 && (thisexd->context & context) != 0
594 && !thisexd->final(s, context, exts[i].present, al))
602 * Construct all the extensions relevant to the current |context| and write
603 * them to |pkt|. If this is an extension for a Certificate in a Certificate
604 * message, then |x| will be set to the Certificate we are handling, and
605 * |chainidx| will indicate the position in the chainidx we are processing (with
606 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
607 * failure occurs then |al| is populated with a suitable alert code. On a
608 * failure construction stops at the first extension to fail to construct.
610 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
611 X509 *x, size_t chainidx, int *al)
614 int addcustom = 0, min_version, max_version = 0, reason, tmpal;
615 const EXTENSION_DEFINITION *thisexd;
618 * Normally if something goes wrong during construction it's an internal
619 * error. We can always override this later.
621 tmpal = SSL_AD_INTERNAL_ERROR;
623 if (!WPACKET_start_sub_packet_u16(pkt)
625 * If extensions are of zero length then we don't even add the
626 * extensions length bytes to a ClientHello/ServerHello in SSLv3
628 || ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
629 && s->version == SSL3_VERSION
630 && !WPACKET_set_flags(pkt,
631 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
632 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
636 if ((context & EXT_CLIENT_HELLO) != 0) {
637 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
639 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
644 /* Add custom extensions first */
645 if ((context & EXT_CLIENT_HELLO) != 0) {
646 custom_ext_init(&s->cert->cli_ext);
648 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
650 * We already initialised the custom extensions during ClientHello
653 * TODO(TLS1.3): We're going to need a new custom extension mechanism
654 * for TLS1.3, so that custom extensions can specify which of the
655 * multiple message they wish to add themselves to.
660 if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) {
661 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
665 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
666 int (*construct)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
667 size_t chainidx, int *al);
669 /* Skip if not relevant for our context */
670 if ((thisexd->context & context) == 0)
673 construct = s->server ? thisexd->construct_stoc
674 : thisexd->construct_ctos;
676 /* Check if this extension is defined for our protocol. If not, skip */
678 && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY)
680 || (s->version == SSL3_VERSION
681 && (thisexd->context & EXT_SSL3_ALLOWED) == 0)
683 && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY)
686 && (thisexd->context & EXT_TLS1_3_ONLY) != 0
687 && (context & EXT_CLIENT_HELLO) == 0)
688 || ((thisexd->context & EXT_TLS1_3_ONLY) != 0
689 && (context & EXT_CLIENT_HELLO) != 0
690 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))
691 || construct == NULL)
694 if (!construct(s, pkt, context, x, chainidx, &tmpal))
698 if (!WPACKET_close(pkt)) {
699 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
711 * Built in extension finalisation and initialisation functions. All initialise
712 * or finalise the associated extension type for the given |context|. For
713 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
714 * otherwise. These functions return 1 on success or 0 on failure. In the event
715 * of a failure then |*al| is populated with a suitable error code.
718 static int final_renegotiate(SSL *s, unsigned int context, int sent,
723 * Check if we can connect to a server that doesn't support safe
726 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
727 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
729 *al = SSL_AD_HANDSHAKE_FAILURE;
730 SSLerr(SSL_F_FINAL_RENEGOTIATE,
731 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
738 /* Need RI if renegotiating */
740 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
742 *al = SSL_AD_HANDSHAKE_FAILURE;
743 SSLerr(SSL_F_FINAL_RENEGOTIATE,
744 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
752 static int init_server_name(SSL *s, unsigned int context)
755 s->servername_done = 0;
760 static int final_server_name(SSL *s, unsigned int context, int sent,
763 int ret = SSL_TLSEXT_ERR_NOACK;
764 int altmp = SSL_AD_UNRECOGNIZED_NAME;
766 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
767 ret = s->ctx->ext.servername_cb(s, &altmp,
768 s->ctx->ext.servername_arg);
769 else if (s->session_ctx != NULL
770 && s->session_ctx->ext.servername_cb != 0)
771 ret = s->session_ctx->ext.servername_cb(s, &altmp,
772 s->session_ctx->ext.servername_arg);
775 case SSL_TLSEXT_ERR_ALERT_FATAL:
779 case SSL_TLSEXT_ERR_ALERT_WARNING:
783 case SSL_TLSEXT_ERR_NOACK:
784 s->servername_done = 0;
792 #ifndef OPENSSL_NO_EC
793 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
796 unsigned long alg_k, alg_a;
801 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
802 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
805 * If we are client and using an elliptic curve cryptography cipher
806 * suite, then if server returns an EC point formats lists extension it
807 * must contain uncompressed.
809 if (s->ext.ecpointformats != NULL
810 && s->ext.ecpointformats_len > 0
811 && s->session->ext.ecpointformats != NULL
812 && s->session->ext.ecpointformats_len > 0
813 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
814 /* we are using an ECC cipher */
816 unsigned char *list = s->session->ext.ecpointformats;
818 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
819 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
822 if (i == s->session->ext.ecpointformats_len) {
823 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
824 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
833 static int init_session_ticket(SSL *s, unsigned int context)
836 s->ext.ticket_expected = 0;
841 #ifndef OPENSSL_NO_OCSP
842 static int init_status_request(SSL *s, unsigned int context)
845 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
848 * Ensure we get sensible values passed to tlsext_status_cb in the event
849 * that we don't receive a status message
851 OPENSSL_free(s->ext.ocsp.resp);
852 s->ext.ocsp.resp = NULL;
853 s->ext.ocsp.resp_len = 0;
860 #ifndef OPENSSL_NO_NEXTPROTONEG
861 static int init_npn(SSL *s, unsigned int context)
869 static int init_alpn(SSL *s, unsigned int context)
871 OPENSSL_free(s->s3->alpn_selected);
872 s->s3->alpn_selected = NULL;
873 s->s3->alpn_selected_len = 0;
875 OPENSSL_free(s->s3->alpn_proposed);
876 s->s3->alpn_proposed = NULL;
877 s->s3->alpn_proposed_len = 0;
882 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
884 const unsigned char *selected = NULL;
885 unsigned char selected_len = 0;
890 if (s->ctx->ext.alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
891 int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len,
892 s->s3->alpn_proposed,
893 (unsigned int)s->s3->alpn_proposed_len,
894 s->ctx->ext.alpn_select_cb_arg);
896 if (r == SSL_TLSEXT_ERR_OK) {
897 OPENSSL_free(s->s3->alpn_selected);
898 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
899 if (s->s3->alpn_selected == NULL) {
900 *al = SSL_AD_INTERNAL_ERROR;
903 s->s3->alpn_selected_len = selected_len;
904 #ifndef OPENSSL_NO_NEXTPROTONEG
905 /* ALPN takes precedence over NPN. */
909 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
917 static int init_sig_algs(SSL *s, unsigned int context)
919 /* Clear any signature algorithms extension received */
920 OPENSSL_free(s->s3->tmp.peer_sigalgs);
921 s->s3->tmp.peer_sigalgs = NULL;
926 #ifndef OPENSSL_NO_SRP
927 static int init_srp(SSL *s, unsigned int context)
929 OPENSSL_free(s->srp_ctx.login);
930 s->srp_ctx.login = NULL;
936 static int init_etm(SSL *s, unsigned int context)
943 static int init_ems(SSL *s, unsigned int context)
946 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
951 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
953 if (!s->server && s->hit) {
955 * Check extended master secret extension is consistent with
958 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
959 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
960 *al = SSL_AD_HANDSHAKE_FAILURE;
961 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
969 #ifndef OPENSSL_NO_SRTP
970 static int init_srtp(SSL *s, unsigned int context)
973 s->srtp_profile = NULL;
979 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
981 if (!sent && SSL_IS_TLS13(s)) {
982 *al = TLS13_AD_MISSING_EXTENSION;
983 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
990 #ifndef OPENSSL_NO_EC
991 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
993 if (!SSL_IS_TLS13(s))
1000 * we have no key_share
1002 * (we are not resuming
1003 * OR the kex_mode doesn't allow non key_share resumes)
1010 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
1011 /* Nothing left we can do - just fail */
1012 *al = SSL_AD_HANDSHAKE_FAILURE;
1013 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1020 * we have no key_share
1023 * we didn't already send a HelloRetryRequest
1025 * the client sent a key_share extension
1027 * (we are not resuming
1028 * OR the kex_mode allows key_share resumes)
1030 * a shared group exists
1032 * send a HelloRetryRequest
1034 * we are not resuming
1036 * the kex_mode doesn't allow non key_share resumes
1040 if (s->server && s->s3->peer_tmp == NULL) {
1041 /* No suitable share */
1042 if (s->hello_retry_request == 0 && sent
1044 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1046 const unsigned char *pcurves, *pcurvestmp, *clntcurves;
1047 size_t num_curves, clnt_num_curves, i;
1048 unsigned int group_id = 0;
1050 /* Check if a shared group exists */
1052 /* Get the clients list of supported groups. */
1053 if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
1054 *al = SSL_AD_INTERNAL_ERROR;
1055 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1059 /* Get our list of available groups */
1060 if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
1061 *al = SSL_AD_INTERNAL_ERROR;
1062 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1066 /* Find the first group we allow that is also in client's list */
1067 for (i = 0, pcurvestmp = pcurves; i < num_curves;
1068 i++, pcurvestmp += 2) {
1069 group_id = bytestogroup(pcurvestmp);
1071 if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1))
1075 if (i < num_curves) {
1076 /* A shared group exists so send a HelloRetryRequest */
1077 s->s3->group_id = group_id;
1078 s->hello_retry_request = 1;
1083 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1084 /* Nothing left we can do - just fail */
1085 *al = SSL_AD_HANDSHAKE_FAILURE;
1086 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1091 /* We have a key_share so don't send any more HelloRetryRequest messages */
1093 s->hello_retry_request = 0;
1096 * For a client side resumption with no key_share we need to generate
1097 * the handshake secret (otherwise this is done during key_share
1100 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
1101 *al = SSL_AD_INTERNAL_ERROR;
1102 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1110 static int init_psk_kex_modes(SSL *s, unsigned int context)
1112 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1116 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1117 size_t binderoffset, const unsigned char *binderin,
1118 unsigned char *binderout,
1119 SSL_SESSION *sess, int sign)
1121 EVP_PKEY *mackey = NULL;
1122 EVP_MD_CTX *mctx = NULL;
1123 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1124 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1125 const char resumption_label[] = "resumption psk binder key";
1126 size_t bindersize, hashsize = EVP_MD_size(md);
1129 /* Generate the early_secret */
1130 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1131 sess->master_key_length,
1132 (unsigned char *)&s->early_secret)) {
1133 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1138 * Create the handshake hash for the binder key...the messages so far are
1141 mctx = EVP_MD_CTX_new();
1143 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1144 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1145 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1149 /* Generate the binder key */
1150 if (!tls13_hkdf_expand(s, md, s->early_secret,
1151 (unsigned char *)resumption_label,
1152 sizeof(resumption_label) - 1, hash, binderkey,
1154 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1158 /* Generate the finished key */
1159 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1160 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1164 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1165 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1170 * Get a hash of the ClientHello up to the start of the binders. If we are
1171 * following a HelloRetryRequest then this includes the hash of the first
1172 * ClientHello and the HelloRetryRequest itself.
1174 if (s->hello_retry_request) {
1178 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
1179 if (hdatalen <= 0) {
1180 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_HANDSHAKE_LENGTH);
1185 * For servers the handshake buffer data will include the second
1186 * ClientHello - which we don't want - so we need to take that bit off.
1189 if (hdatalen < s->init_num + SSL3_HM_HEADER_LENGTH) {
1190 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1193 hdatalen -= s->init_num + SSL3_HM_HEADER_LENGTH;
1196 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1197 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1202 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1203 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1204 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1208 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1209 if (mackey == NULL) {
1210 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1215 binderout = tmpbinder;
1217 bindersize = hashsize;
1218 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1219 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1220 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1221 || bindersize != hashsize) {
1222 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1229 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1230 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1234 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1235 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1236 EVP_PKEY_free(mackey);
1237 EVP_MD_CTX_free(mctx);
1242 static int final_early_data(SSL *s, unsigned int context, int sent, int *al)
1244 if (!s->server || !sent)
1247 if (s->max_early_data == 0
1249 || s->session->ext.tick_identity != 0
1250 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
1251 || !s->ext.early_data_ok
1252 || s->hello_retry_request
1253 || s->s3->alpn_selected_len != s->session->ext.alpn_selected_len
1254 || (s->s3->alpn_selected_len > 0
1255 && memcmp(s->s3->alpn_selected, s->session->ext.alpn_selected,
1256 s->s3->alpn_selected_len) != 0)) {
1257 s->ext.early_data = SSL_EARLY_DATA_REJECTED;
1259 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;
1261 if (!tls13_change_cipher_state(s,
1262 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) {
1263 *al = SSL_AD_INTERNAL_ERROR;