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 static int init_certificate_authorities(SSL *s, unsigned int context);
34 static int tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
35 unsigned int context, X509 *x,
36 size_t chainidx, int *al);
37 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
38 unsigned int context, X509 *x,
39 size_t chainidx, int *al);
40 #ifndef OPENSSL_NO_SRP
41 static int init_srp(SSL *s, unsigned int context);
43 static int init_etm(SSL *s, unsigned int context);
44 static int init_ems(SSL *s, unsigned int context);
45 static int final_ems(SSL *s, unsigned int context, int sent, int *al);
46 static int init_psk_kex_modes(SSL *s, unsigned int context);
48 static int final_key_share(SSL *s, unsigned int context, int sent, int *al);
50 #ifndef OPENSSL_NO_SRTP
51 static int init_srtp(SSL *s, unsigned int context);
53 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al);
54 static int final_early_data(SSL *s, unsigned int context, int sent, int *al);
56 /* Structure to define a built-in extension */
57 typedef struct extensions_definition_st {
58 /* The defined type for the extension */
61 * The context that this extension applies to, e.g. what messages and
66 * Initialise extension before parsing. Always called for relevant contexts
67 * even if extension not present
69 int (*init)(SSL *s, unsigned int context);
70 /* Parse extension sent from client to server */
71 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
72 size_t chainidx, int *al);
73 /* Parse extension send from server to client */
74 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
75 size_t chainidx, int *al);
76 /* Construct extension sent from server to client */
77 int (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
78 size_t chainidx, int *al);
79 /* Construct extension sent from client to server */
80 int (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
81 size_t chainidx, int *al);
83 * Finalise extension after parsing. Always called where an extensions was
84 * initialised even if the extension was not present. |sent| is set to 1 if
85 * the extension was seen, or 0 otherwise.
87 int (*final)(SSL *s, unsigned int context, int sent, int *al);
88 } EXTENSION_DEFINITION;
91 * Definitions of all built-in extensions. NOTE: Changes in the number or order
92 * of these extensions should be mirrored with equivalent changes to the
93 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
94 * Each extension has an initialiser, a client and
95 * server side parser and a finaliser. The initialiser is called (if the
96 * extension is relevant to the given context) even if we did not see the
97 * extension in the message that we received. The parser functions are only
98 * called if we see the extension in the message. The finalisers are always
99 * called if the initialiser was called.
100 * There are also server and client side constructor functions which are always
101 * called during message construction if the extension is relevant for the
103 * The initialisation, parsing, finalisation and construction functions are
104 * always called in the order defined in this list. Some extensions may depend
105 * on others having been processed first, so the order of this list is
107 * The extension context is defined by a series of flags which specify which
108 * messages the extension is relevant to. These flags also specify whether the
109 * extension is relevant to a particular protocol or protocol version.
111 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
113 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
114 static const EXTENSION_DEFINITION ext_defs[] = {
116 TLSEXT_TYPE_renegotiate,
117 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_SSL3_ALLOWED
118 | EXT_TLS1_2_AND_BELOW_ONLY,
119 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
120 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
124 TLSEXT_TYPE_server_name,
125 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
126 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
128 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
129 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
132 #ifndef OPENSSL_NO_SRP
135 EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
136 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
141 #ifndef OPENSSL_NO_EC
143 TLSEXT_TYPE_ec_point_formats,
144 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
145 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
146 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
150 TLSEXT_TYPE_supported_groups,
151 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
152 NULL, tls_parse_ctos_supported_groups, NULL,
153 NULL /* TODO(TLS1.3): Need to add this */,
154 tls_construct_ctos_supported_groups, NULL
161 TLSEXT_TYPE_session_ticket,
162 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
163 init_session_ticket, tls_parse_ctos_session_ticket,
164 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
165 tls_construct_ctos_session_ticket, NULL
168 TLSEXT_TYPE_signature_algorithms,
169 EXT_CLIENT_HELLO | EXT_TLS1_3_CERTIFICATE_REQUEST,
170 init_sig_algs, tls_parse_ctos_sig_algs,
171 tls_parse_ctos_sig_algs, tls_construct_ctos_sig_algs,
172 tls_construct_ctos_sig_algs, final_sig_algs
174 #ifndef OPENSSL_NO_OCSP
176 TLSEXT_TYPE_status_request,
177 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
178 | EXT_TLS1_3_CERTIFICATE,
179 init_status_request, tls_parse_ctos_status_request,
180 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
181 tls_construct_ctos_status_request, NULL
186 #ifndef OPENSSL_NO_NEXTPROTONEG
188 TLSEXT_TYPE_next_proto_neg,
189 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
190 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
191 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
198 * Must appear in this list after server_name so that finalisation
199 * happens after server_name callbacks
201 TLSEXT_TYPE_application_layer_protocol_negotiation,
202 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
203 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
204 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
205 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
207 #ifndef OPENSSL_NO_SRTP
209 TLSEXT_TYPE_use_srtp,
210 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
211 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY,
212 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
213 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
219 TLSEXT_TYPE_encrypt_then_mac,
220 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY | EXT_SSL3_ALLOWED,
221 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
222 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
224 #ifndef OPENSSL_NO_CT
226 TLSEXT_TYPE_signed_certificate_timestamp,
227 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO
228 | EXT_TLS1_3_CERTIFICATE,
231 * No server side support for this, but can be provided by a custom
232 * extension. This is an exception to the rule that custom extensions
233 * cannot override built in ones.
235 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
241 TLSEXT_TYPE_extended_master_secret,
242 EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
243 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
244 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
247 TLSEXT_TYPE_supported_versions,
248 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
250 /* Processed inline as part of version selection */
251 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
254 TLSEXT_TYPE_psk_kex_modes,
255 EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
256 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
257 tls_construct_ctos_psk_kex_modes, NULL
259 #ifndef OPENSSL_NO_EC
262 * Must be in this list after supported_groups. We need that to have
263 * been parsed before we do this one.
265 TLSEXT_TYPE_key_share,
266 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO
267 | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY
269 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
270 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
276 EXT_CLIENT_HELLO | EXT_TLS1_3_HELLO_RETRY_REQUEST
277 | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY,
278 NULL, NULL, tls_parse_stoc_cookie, NULL, tls_construct_ctos_cookie,
283 * Special unsolicited ServerHello extension only used when
284 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
286 TLSEXT_TYPE_cryptopro_bug,
287 EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY,
288 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
291 TLSEXT_TYPE_early_data,
292 EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
293 | EXT_TLS1_3_NEW_SESSION_TICKET,
294 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data,
295 tls_construct_stoc_early_data, tls_construct_ctos_early_data,
299 TLSEXT_TYPE_certificate_authorities,
300 EXT_CLIENT_HELLO | EXT_TLS1_3_CERTIFICATE_REQUEST | EXT_TLS1_3_ONLY,
301 init_certificate_authorities,
302 tls_parse_certificate_authorities, tls_parse_certificate_authorities,
303 tls_construct_certificate_authorities,
304 tls_construct_certificate_authorities, NULL,
307 /* Must be immediately before pre_shared_key */
311 /* We send this, but don't read it */
312 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
315 /* Required by the TLSv1.3 spec to always be the last extension */
317 EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO | EXT_TLS_IMPLEMENTATION_ONLY
319 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
320 tls_construct_ctos_psk, NULL
325 * Verify whether we are allowed to use the extension |type| in the current
326 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
327 * indicate the extension is not allowed. If returning 1 then |*found| is set to
328 * 1 if we found a definition for the extension, and |*idx| is set to its index
330 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
331 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
332 RAW_EXTENSION **found)
335 size_t builtin_num = OSSL_NELEM(ext_defs);
336 const EXTENSION_DEFINITION *thisext;
338 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
339 if (type == thisext->type) {
340 /* Check we're allowed to use this extension in this context */
341 if ((context & thisext->context) == 0)
344 if (SSL_IS_DTLS(s)) {
345 if ((thisext->context & EXT_TLS_ONLY) != 0)
347 } else if ((thisext->context & EXT_DTLS_ONLY) != 0) {
351 *found = &rawexlist[i];
356 if ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) == 0) {
358 * Custom extensions only apply to <=TLS1.2. This extension is unknown
359 * in this context - we allow it
365 /* Check the custom extensions */
367 for (i = builtin_num; i < builtin_num + meths->meths_count; i++) {
368 if (meths->meths[i - builtin_num].ext_type == type) {
369 *found = &rawexlist[i];
375 /* Unknown extension. We allow it */
381 * Check whether the context defined for an extension |extctx| means whether
382 * the extension is relevant for the current context |thisctx| or not. Returns
383 * 1 if the extension is relevant for this context, and 0 otherwise
385 static int extension_is_relevant(SSL *s, unsigned int extctx,
386 unsigned int thisctx)
389 && (extctx & EXT_TLS_IMPLEMENTATION_ONLY) != 0)
390 || (s->version == SSL3_VERSION
391 && (extctx & EXT_SSL3_ALLOWED) == 0)
393 && (extctx & EXT_TLS1_2_AND_BELOW_ONLY) != 0)
394 || (!SSL_IS_TLS13(s) && (extctx & EXT_TLS1_3_ONLY) != 0))
401 * Gather a list of all the extensions from the data in |packet]. |context|
402 * tells us which message this extension is for. The raw extension data is
403 * stored in |*res| on success. In the event of an error the alert type to use
404 * is stored in |*al|. We don't actually process the content of the extensions
405 * yet, except to check their types. This function also runs the initialiser
406 * functions for all known extensions (whether we have collected them or not).
407 * If successful the caller is responsible for freeing the contents of |*res|.
409 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
410 * more than one extension of the same type in a ClientHello or ServerHello.
411 * This function returns 1 if all extensions are unique and we have parsed their
412 * types, and 0 if the extensions contain duplicates, could not be successfully
413 * found, or an internal error occurred. We only check duplicates for
414 * extensions that we know about. We ignore others.
416 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
417 RAW_EXTENSION **res, int *al, size_t *len)
419 PACKET extensions = *packet;
422 custom_ext_methods *exts = NULL;
423 RAW_EXTENSION *raw_extensions = NULL;
424 const EXTENSION_DEFINITION *thisexd;
429 * Initialise server side custom extensions. Client side is done during
430 * construction of extensions for the ClientHello.
432 if ((context & EXT_CLIENT_HELLO) != 0) {
433 exts = &s->cert->srv_ext;
434 custom_ext_init(&s->cert->srv_ext);
435 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
436 exts = &s->cert->cli_ext;
439 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
440 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
441 if (raw_extensions == NULL) {
442 *al = SSL_AD_INTERNAL_ERROR;
443 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
447 while (PACKET_remaining(&extensions) > 0) {
450 RAW_EXTENSION *thisex;
452 if (!PACKET_get_net_2(&extensions, &type) ||
453 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
454 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
455 *al = SSL_AD_DECODE_ERROR;
459 * Verify this extension is allowed. We only check duplicates for
460 * extensions that we recognise. We also have a special case for the
461 * PSK extension, which must be the last one in the ClientHello.
463 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
464 || (thisex != NULL && thisex->present == 1)
465 || (type == TLSEXT_TYPE_psk
466 && (context & EXT_CLIENT_HELLO) != 0
467 && PACKET_remaining(&extensions) != 0)) {
468 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
469 *al = SSL_AD_ILLEGAL_PARAMETER;
472 if (thisex != NULL) {
473 thisex->data = extension;
480 * Initialise all known extensions relevant to this context, whether we have
483 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
484 if(thisexd->init != NULL && (thisexd->context & context) != 0
485 && extension_is_relevant(s, thisexd->context, context)
486 && !thisexd->init(s, context)) {
487 *al = SSL_AD_INTERNAL_ERROR;
492 *res = raw_extensions;
498 OPENSSL_free(raw_extensions);
503 * Runs the parser for a given extension with index |idx|. |exts| contains the
504 * list of all parsed extensions previously collected by
505 * tls_collect_extensions(). The parser is only run if it is applicable for the
506 * given |context| and the parser has not already been run. If this is for a
507 * Certificate message, then we also provide the parser with the relevant
508 * Certificate |x| and its position in the |chainidx| with 0 being the first
509 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
510 * |*al| is populated with a suitable alert code. If an extension is not present
511 * this counted as success.
513 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
514 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
516 RAW_EXTENSION *currext = &exts[idx];
517 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
518 size_t chainidx, int *al) = NULL;
520 /* Skip if the extension is not present */
521 if (!currext->present)
525 s->ext.debug_cb(s, !s->server, currext->type,
526 PACKET_data(&currext->data),
527 PACKET_remaining(&currext->data),
530 /* Skip if we've already parsed this extension */
536 if (idx < OSSL_NELEM(ext_defs)) {
537 /* We are handling a built-in extension */
538 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
540 /* Check if extension is defined for our protocol. If not, skip */
541 if (!extension_is_relevant(s, extdef->context, context))
544 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
547 return parser(s, &currext->data, context, x, chainidx, al);
550 * If the parser is NULL we fall through to the custom extension
556 * This is a custom extension. We only allow this if it is a non
557 * resumed session on the server side.
559 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
560 * We're going to need a new mechanism for TLS1.3 to specify which
561 * messages to add the custom extensions to.
563 if ((!s->hit || !s->server)
565 & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
566 && custom_ext_parse(s, s->server, currext->type,
567 PACKET_data(&currext->data),
568 PACKET_remaining(&currext->data),
576 * Parse all remaining extensions that have not yet been parsed. Also calls the
577 * finalisation for all extensions at the end, whether we collected them or not.
578 * Returns 1 for success or 0 for failure. If we are working on a Certificate
579 * message then we also pass the Certificate |x| and its position in the
580 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
581 * populated with a suitable alert code.
583 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
584 size_t chainidx, int *al)
586 size_t i, numexts = OSSL_NELEM(ext_defs);
587 const EXTENSION_DEFINITION *thisexd;
589 /* Calculate the number of extensions in the extensions list */
590 if ((context & EXT_CLIENT_HELLO) != 0) {
591 numexts += s->cert->srv_ext.meths_count;
592 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
593 numexts += s->cert->cli_ext.meths_count;
596 /* Parse each extension in turn */
597 for (i = 0; i < numexts; i++) {
598 if (!tls_parse_extension(s, i, context, exts, x, chainidx, al))
603 * Finalise all known extensions relevant to this context, whether we have
606 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
607 if(thisexd->final != NULL
608 && (thisexd->context & context) != 0
609 && !thisexd->final(s, context, exts[i].present, al))
617 * Construct all the extensions relevant to the current |context| and write
618 * them to |pkt|. If this is an extension for a Certificate in a Certificate
619 * message, then |x| will be set to the Certificate we are handling, and
620 * |chainidx| will indicate the position in the chainidx we are processing (with
621 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
622 * failure occurs then |al| is populated with a suitable alert code. On a
623 * failure construction stops at the first extension to fail to construct.
625 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
626 X509 *x, size_t chainidx, int *al)
629 int addcustom = 0, min_version, max_version = 0, reason, tmpal;
630 const EXTENSION_DEFINITION *thisexd;
633 * Normally if something goes wrong during construction it's an internal
634 * error. We can always override this later.
636 tmpal = SSL_AD_INTERNAL_ERROR;
638 if (!WPACKET_start_sub_packet_u16(pkt)
640 * If extensions are of zero length then we don't even add the
641 * extensions length bytes to a ClientHello/ServerHello in SSLv3
643 || ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0
644 && s->version == SSL3_VERSION
645 && !WPACKET_set_flags(pkt,
646 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
647 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
651 if ((context & EXT_CLIENT_HELLO) != 0) {
652 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
654 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
659 /* Add custom extensions first */
660 if ((context & EXT_CLIENT_HELLO) != 0) {
661 custom_ext_init(&s->cert->cli_ext);
663 } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) {
665 * We already initialised the custom extensions during ClientHello
668 * TODO(TLS1.3): We're going to need a new custom extension mechanism
669 * for TLS1.3, so that custom extensions can specify which of the
670 * multiple message they wish to add themselves to.
675 if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) {
676 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
680 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
681 int (*construct)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
682 size_t chainidx, int *al);
684 /* Skip if not relevant for our context */
685 if ((thisexd->context & context) == 0)
688 construct = s->server ? thisexd->construct_stoc
689 : thisexd->construct_ctos;
691 /* Check if this extension is defined for our protocol. If not, skip */
693 && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY)
695 || (s->version == SSL3_VERSION
696 && (thisexd->context & EXT_SSL3_ALLOWED) == 0)
698 && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY)
701 && (thisexd->context & EXT_TLS1_3_ONLY) != 0
702 && (context & EXT_CLIENT_HELLO) == 0)
703 || ((thisexd->context & EXT_TLS1_3_ONLY) != 0
704 && (context & EXT_CLIENT_HELLO) != 0
705 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))
706 || construct == NULL)
709 if (!construct(s, pkt, context, x, chainidx, &tmpal))
713 if (!WPACKET_close(pkt)) {
714 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
726 * Built in extension finalisation and initialisation functions. All initialise
727 * or finalise the associated extension type for the given |context|. For
728 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
729 * otherwise. These functions return 1 on success or 0 on failure. In the event
730 * of a failure then |*al| is populated with a suitable error code.
733 static int final_renegotiate(SSL *s, unsigned int context, int sent,
738 * Check if we can connect to a server that doesn't support safe
741 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
742 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
744 *al = SSL_AD_HANDSHAKE_FAILURE;
745 SSLerr(SSL_F_FINAL_RENEGOTIATE,
746 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
753 /* Need RI if renegotiating */
755 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
757 *al = SSL_AD_HANDSHAKE_FAILURE;
758 SSLerr(SSL_F_FINAL_RENEGOTIATE,
759 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
767 static int init_server_name(SSL *s, unsigned int context)
770 s->servername_done = 0;
775 static int final_server_name(SSL *s, unsigned int context, int sent,
778 int ret = SSL_TLSEXT_ERR_NOACK;
779 int altmp = SSL_AD_UNRECOGNIZED_NAME;
781 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
782 ret = s->ctx->ext.servername_cb(s, &altmp,
783 s->ctx->ext.servername_arg);
784 else if (s->session_ctx != NULL
785 && s->session_ctx->ext.servername_cb != 0)
786 ret = s->session_ctx->ext.servername_cb(s, &altmp,
787 s->session_ctx->ext.servername_arg);
790 case SSL_TLSEXT_ERR_ALERT_FATAL:
794 case SSL_TLSEXT_ERR_ALERT_WARNING:
798 case SSL_TLSEXT_ERR_NOACK:
799 s->servername_done = 0;
807 #ifndef OPENSSL_NO_EC
808 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
811 unsigned long alg_k, alg_a;
816 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
817 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
820 * If we are client and using an elliptic curve cryptography cipher
821 * suite, then if server returns an EC point formats lists extension it
822 * must contain uncompressed.
824 if (s->ext.ecpointformats != NULL
825 && s->ext.ecpointformats_len > 0
826 && s->session->ext.ecpointformats != NULL
827 && s->session->ext.ecpointformats_len > 0
828 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
829 /* we are using an ECC cipher */
831 unsigned char *list = s->session->ext.ecpointformats;
833 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
834 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
837 if (i == s->session->ext.ecpointformats_len) {
838 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
839 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
848 static int init_session_ticket(SSL *s, unsigned int context)
851 s->ext.ticket_expected = 0;
856 #ifndef OPENSSL_NO_OCSP
857 static int init_status_request(SSL *s, unsigned int context)
860 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
863 * Ensure we get sensible values passed to tlsext_status_cb in the event
864 * that we don't receive a status message
866 OPENSSL_free(s->ext.ocsp.resp);
867 s->ext.ocsp.resp = NULL;
868 s->ext.ocsp.resp_len = 0;
875 #ifndef OPENSSL_NO_NEXTPROTONEG
876 static int init_npn(SSL *s, unsigned int context)
884 static int init_alpn(SSL *s, unsigned int context)
886 OPENSSL_free(s->s3->alpn_selected);
887 s->s3->alpn_selected = NULL;
888 s->s3->alpn_selected_len = 0;
890 OPENSSL_free(s->s3->alpn_proposed);
891 s->s3->alpn_proposed = NULL;
892 s->s3->alpn_proposed_len = 0;
897 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
899 const unsigned char *selected = NULL;
900 unsigned char selected_len = 0;
905 if (s->ctx->ext.alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
906 int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len,
907 s->s3->alpn_proposed,
908 (unsigned int)s->s3->alpn_proposed_len,
909 s->ctx->ext.alpn_select_cb_arg);
911 if (r == SSL_TLSEXT_ERR_OK) {
912 OPENSSL_free(s->s3->alpn_selected);
913 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
914 if (s->s3->alpn_selected == NULL) {
915 *al = SSL_AD_INTERNAL_ERROR;
918 s->s3->alpn_selected_len = selected_len;
919 #ifndef OPENSSL_NO_NEXTPROTONEG
920 /* ALPN takes precedence over NPN. */
924 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
932 static int init_sig_algs(SSL *s, unsigned int context)
934 /* Clear any signature algorithms extension received */
935 OPENSSL_free(s->s3->tmp.peer_sigalgs);
936 s->s3->tmp.peer_sigalgs = NULL;
941 #ifndef OPENSSL_NO_SRP
942 static int init_srp(SSL *s, unsigned int context)
944 OPENSSL_free(s->srp_ctx.login);
945 s->srp_ctx.login = NULL;
951 static int init_etm(SSL *s, unsigned int context)
958 static int init_ems(SSL *s, unsigned int context)
961 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
966 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
968 if (!s->server && s->hit) {
970 * Check extended master secret extension is consistent with
973 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
974 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
975 *al = SSL_AD_HANDSHAKE_FAILURE;
976 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
984 static int init_certificate_authorities(SSL *s, unsigned int context)
986 sk_X509_NAME_pop_free(s->s3->tmp.ca_names, X509_NAME_free);
987 s->s3->tmp.ca_names = NULL;
991 static int tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
992 unsigned int context, X509 *x,
993 size_t chainidx, int *al)
995 STACK_OF(X509_NAME) *ca_sk = SSL_get_client_CA_list(s);
997 if (ca_sk == NULL || sk_X509_NAME_num(ca_sk) == 0)
1000 if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_certificate_authorities)
1001 || !WPACKET_start_sub_packet_u16(pkt)
1002 || !construct_ca_names(s, pkt)
1003 || !WPACKET_close(pkt)) {
1004 SSLerr(SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,
1005 ERR_R_INTERNAL_ERROR);
1012 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
1013 unsigned int context, X509 *x,
1014 size_t chainidx, int *al)
1016 if (!parse_ca_names(s, pkt, al))
1018 if (PACKET_remaining(pkt) != 0) {
1019 *al = SSL_AD_DECODE_ERROR;
1025 #ifndef OPENSSL_NO_SRTP
1026 static int init_srtp(SSL *s, unsigned int context)
1029 s->srtp_profile = NULL;
1035 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
1037 if (!sent && SSL_IS_TLS13(s)) {
1038 *al = TLS13_AD_MISSING_EXTENSION;
1039 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
1046 #ifndef OPENSSL_NO_EC
1047 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
1049 if (!SSL_IS_TLS13(s))
1056 * we have no key_share
1058 * (we are not resuming
1059 * OR the kex_mode doesn't allow non key_share resumes)
1066 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
1067 /* Nothing left we can do - just fail */
1068 *al = SSL_AD_HANDSHAKE_FAILURE;
1069 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1076 * we have no key_share
1079 * we didn't already send a HelloRetryRequest
1081 * the client sent a key_share extension
1083 * (we are not resuming
1084 * OR the kex_mode allows key_share resumes)
1086 * a shared group exists
1088 * send a HelloRetryRequest
1090 * we are not resuming
1092 * the kex_mode doesn't allow non key_share resumes
1096 if (s->server && s->s3->peer_tmp == NULL) {
1097 /* No suitable share */
1098 if (s->hello_retry_request == 0 && sent
1100 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1102 const unsigned char *pcurves, *pcurvestmp, *clntcurves;
1103 size_t num_curves, clnt_num_curves, i;
1104 unsigned int group_id = 0;
1106 /* Check if a shared group exists */
1108 /* Get the clients list of supported groups. */
1109 if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
1110 *al = SSL_AD_INTERNAL_ERROR;
1111 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1115 /* Get our list of available groups */
1116 if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
1117 *al = SSL_AD_INTERNAL_ERROR;
1118 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1122 /* Find the first group we allow that is also in client's list */
1123 for (i = 0, pcurvestmp = pcurves; i < num_curves;
1124 i++, pcurvestmp += 2) {
1125 group_id = bytestogroup(pcurvestmp);
1127 if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1))
1131 if (i < num_curves) {
1132 /* A shared group exists so send a HelloRetryRequest */
1133 s->s3->group_id = group_id;
1134 s->hello_retry_request = 1;
1139 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1140 /* Nothing left we can do - just fail */
1141 *al = SSL_AD_HANDSHAKE_FAILURE;
1142 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1147 /* We have a key_share so don't send any more HelloRetryRequest messages */
1149 s->hello_retry_request = 0;
1152 * For a client side resumption with no key_share we need to generate
1153 * the handshake secret (otherwise this is done during key_share
1156 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
1157 *al = SSL_AD_INTERNAL_ERROR;
1158 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1166 static int init_psk_kex_modes(SSL *s, unsigned int context)
1168 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1172 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1173 size_t binderoffset, const unsigned char *binderin,
1174 unsigned char *binderout,
1175 SSL_SESSION *sess, int sign)
1177 EVP_PKEY *mackey = NULL;
1178 EVP_MD_CTX *mctx = NULL;
1179 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1180 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1181 const char resumption_label[] = "resumption psk binder key";
1182 size_t bindersize, hashsize = EVP_MD_size(md);
1185 /* Generate the early_secret */
1186 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1187 sess->master_key_length,
1188 (unsigned char *)&s->early_secret)) {
1189 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1194 * Create the handshake hash for the binder key...the messages so far are
1197 mctx = EVP_MD_CTX_new();
1199 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1200 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1201 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1205 /* Generate the binder key */
1206 if (!tls13_hkdf_expand(s, md, s->early_secret,
1207 (unsigned char *)resumption_label,
1208 sizeof(resumption_label) - 1, hash, binderkey,
1210 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1214 /* Generate the finished key */
1215 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1216 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1220 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1221 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1226 * Get a hash of the ClientHello up to the start of the binders. If we are
1227 * following a HelloRetryRequest then this includes the hash of the first
1228 * ClientHello and the HelloRetryRequest itself.
1230 if (s->hello_retry_request) {
1234 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
1235 if (hdatalen <= 0) {
1236 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_HANDSHAKE_LENGTH);
1241 * For servers the handshake buffer data will include the second
1242 * ClientHello - which we don't want - so we need to take that bit off.
1245 if (hdatalen < s->init_num + SSL3_HM_HEADER_LENGTH) {
1246 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1249 hdatalen -= s->init_num + SSL3_HM_HEADER_LENGTH;
1252 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1253 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1258 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1259 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1260 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1264 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1265 if (mackey == NULL) {
1266 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1271 binderout = tmpbinder;
1273 bindersize = hashsize;
1274 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1275 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1276 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1277 || bindersize != hashsize) {
1278 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1285 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1286 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1290 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1291 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1292 EVP_PKEY_free(mackey);
1293 EVP_MD_CTX_free(mctx);
1298 static int final_early_data(SSL *s, unsigned int context, int sent, int *al)
1300 if (!s->server || !sent)
1303 if (s->max_early_data == 0
1305 || s->session->ext.tick_identity != 0
1306 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
1307 || !s->ext.early_data_ok
1308 || s->hello_retry_request
1309 || s->s3->alpn_selected_len != s->session->ext.alpn_selected_len
1310 || (s->s3->alpn_selected_len > 0
1311 && memcmp(s->s3->alpn_selected, s->session->ext.alpn_selected,
1312 s->s3->alpn_selected_len) != 0)) {
1313 s->ext.early_data = SSL_EARLY_DATA_REJECTED;
1315 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;
1317 if (!tls13_change_cipher_state(s,
1318 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) {
1319 *al = SSL_AD_INTERNAL_ERROR;