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 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
118 | SSL_EXT_SSL3_ALLOWED | SSL_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 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
126 | SSL_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 SSL_EXT_CLIENT_HELLO | SSL_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 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
145 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
146 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
147 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
151 TLSEXT_TYPE_supported_groups,
152 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
153 NULL, tls_parse_ctos_supported_groups, NULL,
154 NULL /* TODO(TLS1.3): Need to add this */,
155 tls_construct_ctos_supported_groups, NULL
162 TLSEXT_TYPE_session_ticket,
163 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
164 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
165 init_session_ticket, tls_parse_ctos_session_ticket,
166 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
167 tls_construct_ctos_session_ticket, NULL
170 TLSEXT_TYPE_signature_algorithms,
171 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
172 init_sig_algs, tls_parse_ctos_sig_algs,
173 tls_parse_ctos_sig_algs, tls_construct_ctos_sig_algs,
174 tls_construct_ctos_sig_algs, final_sig_algs
176 #ifndef OPENSSL_NO_OCSP
178 TLSEXT_TYPE_status_request,
179 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
180 | SSL_EXT_TLS1_3_CERTIFICATE,
181 init_status_request, tls_parse_ctos_status_request,
182 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
183 tls_construct_ctos_status_request, NULL
188 #ifndef OPENSSL_NO_NEXTPROTONEG
190 TLSEXT_TYPE_next_proto_neg,
191 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
192 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
193 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
194 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
201 * Must appear in this list after server_name so that finalisation
202 * happens after server_name callbacks
204 TLSEXT_TYPE_application_layer_protocol_negotiation,
205 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
206 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
207 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
208 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
210 #ifndef OPENSSL_NO_SRTP
212 TLSEXT_TYPE_use_srtp,
213 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
214 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS | SSL_EXT_DTLS_ONLY,
215 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
216 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
222 TLSEXT_TYPE_encrypt_then_mac,
223 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
224 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
225 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
226 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
228 #ifndef OPENSSL_NO_CT
230 TLSEXT_TYPE_signed_certificate_timestamp,
231 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
232 | SSL_EXT_TLS1_3_CERTIFICATE,
235 * No server side support for this, but can be provided by a custom
236 * extension. This is an exception to the rule that custom extensions
237 * cannot override built in ones.
239 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
245 TLSEXT_TYPE_extended_master_secret,
246 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
247 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
248 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
249 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
252 TLSEXT_TYPE_supported_versions,
253 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY
254 | SSL_EXT_TLS1_3_ONLY,
256 /* Processed inline as part of version selection */
257 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
260 TLSEXT_TYPE_psk_kex_modes,
261 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY
262 | SSL_EXT_TLS1_3_ONLY,
263 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
264 tls_construct_ctos_psk_kex_modes, NULL
266 #ifndef OPENSSL_NO_EC
269 * Must be in this list after supported_groups. We need that to have
270 * been parsed before we do this one.
272 TLSEXT_TYPE_key_share,
273 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
274 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY
275 | SSL_EXT_TLS1_3_ONLY,
276 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
277 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
283 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
284 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
285 NULL, NULL, tls_parse_stoc_cookie, NULL, tls_construct_ctos_cookie,
290 * Special unsolicited ServerHello extension only used when
291 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
293 TLSEXT_TYPE_cryptopro_bug,
294 SSL_EXT_TLS1_2_SERVER_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
295 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
298 TLSEXT_TYPE_early_data,
299 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
300 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
301 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data,
302 tls_construct_stoc_early_data, tls_construct_ctos_early_data,
306 TLSEXT_TYPE_certificate_authorities,
307 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
308 | SSL_EXT_TLS1_3_ONLY,
309 init_certificate_authorities,
310 tls_parse_certificate_authorities, tls_parse_certificate_authorities,
311 tls_construct_certificate_authorities,
312 tls_construct_certificate_authorities, NULL,
315 /* Must be immediately before pre_shared_key */
317 SSL_EXT_CLIENT_HELLO,
319 /* We send this, but don't read it */
320 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
323 /* Required by the TLSv1.3 spec to always be the last extension */
325 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
326 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
327 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
328 tls_construct_ctos_psk, NULL
332 /* Check whether an extension's context matches the current context */
333 static int validate_context(SSL *s, unsigned int extctx, unsigned int thisctx)
335 /* Check we're allowed to use this extension in this context */
336 if ((thisctx & extctx) == 0)
339 if (SSL_IS_DTLS(s)) {
340 if ((extctx & SSL_EXT_TLS_ONLY) != 0)
342 } else if ((extctx & SSL_EXT_DTLS_ONLY) != 0) {
350 * Verify whether we are allowed to use the extension |type| in the current
351 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
352 * indicate the extension is not allowed. If returning 1 then |*found| is set to
353 * the definition for the extension we found.
355 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
356 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
357 RAW_EXTENSION **found)
360 size_t builtin_num = OSSL_NELEM(ext_defs);
361 const EXTENSION_DEFINITION *thisext;
363 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
364 if (type == thisext->type) {
365 if (!validate_context(s, thisext->context, context))
368 *found = &rawexlist[i];
373 /* Check the custom extensions */
376 ENDPOINT role = ENDPOINT_BOTH;
377 custom_ext_method *meth = NULL;
379 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
380 role = ENDPOINT_SERVER;
381 else if ((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0)
382 role = ENDPOINT_CLIENT;
384 meth = custom_ext_find(meths, role, type, &offset);
386 if (!validate_context(s, meth->context, context))
388 *found = &rawexlist[offset + builtin_num];
393 /* Unknown extension. We allow it */
399 * Check whether the context defined for an extension |extctx| means whether
400 * the extension is relevant for the current context |thisctx| or not. Returns
401 * 1 if the extension is relevant for this context, and 0 otherwise
403 int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx)
406 && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0)
407 || (s->version == SSL3_VERSION
408 && (extctx & SSL_EXT_SSL3_ALLOWED) == 0)
410 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
411 || (!SSL_IS_TLS13(s) && (extctx & SSL_EXT_TLS1_3_ONLY) != 0)
412 || (s->hit && (extctx & SSL_EXT_IGNORE_ON_RESUMPTION) != 0))
419 * Gather a list of all the extensions from the data in |packet]. |context|
420 * tells us which message this extension is for. The raw extension data is
421 * stored in |*res| on success. In the event of an error the alert type to use
422 * is stored in |*al|. We don't actually process the content of the extensions
423 * yet, except to check their types. This function also runs the initialiser
424 * functions for all known extensions (whether we have collected them or not).
425 * If successful the caller is responsible for freeing the contents of |*res|.
427 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
428 * more than one extension of the same type in a ClientHello or ServerHello.
429 * This function returns 1 if all extensions are unique and we have parsed their
430 * types, and 0 if the extensions contain duplicates, could not be successfully
431 * found, or an internal error occurred. We only check duplicates for
432 * extensions that we know about. We ignore others.
434 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
435 RAW_EXTENSION **res, int *al, size_t *len)
437 PACKET extensions = *packet;
440 custom_ext_methods *exts = &s->cert->custext;
441 RAW_EXTENSION *raw_extensions = NULL;
442 const EXTENSION_DEFINITION *thisexd;
447 * Initialise server side custom extensions. Client side is done during
448 * construction of extensions for the ClientHello.
450 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
451 custom_ext_init(&s->cert->custext);
453 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
454 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
455 if (raw_extensions == NULL) {
456 *al = SSL_AD_INTERNAL_ERROR;
457 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
461 while (PACKET_remaining(&extensions) > 0) {
464 RAW_EXTENSION *thisex;
466 if (!PACKET_get_net_2(&extensions, &type) ||
467 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
468 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
469 *al = SSL_AD_DECODE_ERROR;
473 * Verify this extension is allowed. We only check duplicates for
474 * extensions that we recognise. We also have a special case for the
475 * PSK extension, which must be the last one in the ClientHello.
477 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
478 || (thisex != NULL && thisex->present == 1)
479 || (type == TLSEXT_TYPE_psk
480 && (context & SSL_EXT_CLIENT_HELLO) != 0
481 && PACKET_remaining(&extensions) != 0)) {
482 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
483 *al = SSL_AD_ILLEGAL_PARAMETER;
486 if (thisex != NULL) {
487 thisex->data = extension;
494 * Initialise all known extensions relevant to this context, whether we have
497 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
498 if(thisexd->init != NULL && (thisexd->context & context) != 0
499 && extension_is_relevant(s, thisexd->context, context)
500 && !thisexd->init(s, context)) {
501 *al = SSL_AD_INTERNAL_ERROR;
506 *res = raw_extensions;
512 OPENSSL_free(raw_extensions);
517 * Runs the parser for a given extension with index |idx|. |exts| contains the
518 * list of all parsed extensions previously collected by
519 * tls_collect_extensions(). The parser is only run if it is applicable for the
520 * given |context| and the parser has not already been run. If this is for a
521 * Certificate message, then we also provide the parser with the relevant
522 * Certificate |x| and its position in the |chainidx| with 0 being the first
523 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
524 * |*al| is populated with a suitable alert code. If an extension is not present
525 * this counted as success.
527 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
528 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
530 RAW_EXTENSION *currext = &exts[idx];
531 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
532 size_t chainidx, int *al) = NULL;
534 /* Skip if the extension is not present */
535 if (!currext->present)
539 s->ext.debug_cb(s, !s->server, currext->type,
540 PACKET_data(&currext->data),
541 PACKET_remaining(&currext->data),
544 /* Skip if we've already parsed this extension */
550 if (idx < OSSL_NELEM(ext_defs)) {
551 /* We are handling a built-in extension */
552 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
554 /* Check if extension is defined for our protocol. If not, skip */
555 if (!extension_is_relevant(s, extdef->context, context))
558 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
561 return parser(s, &currext->data, context, x, chainidx, al);
564 * If the parser is NULL we fall through to the custom extension
569 /* Parse custom extensions */
570 if (custom_ext_parse(s, context, currext->type,
571 PACKET_data(&currext->data),
572 PACKET_remaining(&currext->data),
573 x, chainidx, al) <= 0)
580 * Parse all remaining extensions that have not yet been parsed. Also calls the
581 * finalisation for all extensions at the end, whether we collected them or not.
582 * Returns 1 for success or 0 for failure. If we are working on a Certificate
583 * message then we also pass the Certificate |x| and its position in the
584 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
585 * populated with a suitable alert code.
587 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
588 size_t chainidx, int *al)
590 size_t i, numexts = OSSL_NELEM(ext_defs);
591 const EXTENSION_DEFINITION *thisexd;
593 /* Calculate the number of extensions in the extensions list */
594 numexts += s->cert->custext.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))
616 int should_add_extension(SSL *s, unsigned int extctx, unsigned int thisctx,
619 /* Skip if not relevant for our context */
620 if ((extctx & thisctx) == 0)
623 /* Check if this extension is defined for our protocol. If not, skip */
624 if ((SSL_IS_DTLS(s) && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0)
625 || (s->version == SSL3_VERSION
626 && (extctx & SSL_EXT_SSL3_ALLOWED) == 0)
628 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
630 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0
631 && (thisctx & SSL_EXT_CLIENT_HELLO) == 0)
632 || ((extctx & SSL_EXT_TLS1_3_ONLY) != 0
633 && (thisctx & SSL_EXT_CLIENT_HELLO) != 0
634 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION)))
641 * Construct all the extensions relevant to the current |context| and write
642 * them to |pkt|. If this is an extension for a Certificate in a Certificate
643 * message, then |x| will be set to the Certificate we are handling, and
644 * |chainidx| will indicate the position in the chainidx we are processing (with
645 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
646 * failure occurs then |al| is populated with a suitable alert code. On a
647 * failure construction stops at the first extension to fail to construct.
649 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
650 X509 *x, size_t chainidx, int *al)
653 int min_version, max_version = 0, reason, tmpal;
654 const EXTENSION_DEFINITION *thisexd;
657 * Normally if something goes wrong during construction it's an internal
658 * error. We can always override this later.
660 tmpal = SSL_AD_INTERNAL_ERROR;
662 if (!WPACKET_start_sub_packet_u16(pkt)
664 * If extensions are of zero length then we don't even add the
665 * extensions length bytes to a ClientHello/ServerHello in SSLv3
668 (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0
669 && s->version == SSL3_VERSION
670 && !WPACKET_set_flags(pkt,
671 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
672 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
676 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
677 reason = ssl_get_client_min_max_version(s, &min_version, &max_version);
679 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
684 /* Add custom extensions first */
685 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
686 /* On the server side with initiase during ClientHello parsing */
687 custom_ext_init(&s->cert->custext);
689 if (!custom_ext_add(s, context, pkt, x, chainidx, max_version, &tmpal)) {
690 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
694 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
695 int (*construct)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
696 size_t chainidx, int *al);
698 /* Skip if not relevant for our context */
699 if (!should_add_extension(s, thisexd->context, context, max_version))
702 construct = s->server ? thisexd->construct_stoc
703 : thisexd->construct_ctos;
705 if (construct == NULL)
708 if (!construct(s, pkt, context, x, chainidx, &tmpal))
712 if (!WPACKET_close(pkt)) {
713 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
725 * Built in extension finalisation and initialisation functions. All initialise
726 * or finalise the associated extension type for the given |context|. For
727 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
728 * otherwise. These functions return 1 on success or 0 on failure. In the event
729 * of a failure then |*al| is populated with a suitable error code.
732 static int final_renegotiate(SSL *s, unsigned int context, int sent,
737 * Check if we can connect to a server that doesn't support safe
740 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
741 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
743 *al = SSL_AD_HANDSHAKE_FAILURE;
744 SSLerr(SSL_F_FINAL_RENEGOTIATE,
745 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
752 /* Need RI if renegotiating */
754 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
756 *al = SSL_AD_HANDSHAKE_FAILURE;
757 SSLerr(SSL_F_FINAL_RENEGOTIATE,
758 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
766 static int init_server_name(SSL *s, unsigned int context)
769 s->servername_done = 0;
774 static int final_server_name(SSL *s, unsigned int context, int sent,
777 int ret = SSL_TLSEXT_ERR_NOACK;
778 int altmp = SSL_AD_UNRECOGNIZED_NAME;
780 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
781 ret = s->ctx->ext.servername_cb(s, &altmp,
782 s->ctx->ext.servername_arg);
783 else if (s->session_ctx != NULL
784 && s->session_ctx->ext.servername_cb != 0)
785 ret = s->session_ctx->ext.servername_cb(s, &altmp,
786 s->session_ctx->ext.servername_arg);
789 case SSL_TLSEXT_ERR_ALERT_FATAL:
793 case SSL_TLSEXT_ERR_ALERT_WARNING:
797 case SSL_TLSEXT_ERR_NOACK:
798 s->servername_done = 0;
806 #ifndef OPENSSL_NO_EC
807 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
810 unsigned long alg_k, alg_a;
815 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
816 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
819 * If we are client and using an elliptic curve cryptography cipher
820 * suite, then if server returns an EC point formats lists extension it
821 * must contain uncompressed.
823 if (s->ext.ecpointformats != NULL
824 && s->ext.ecpointformats_len > 0
825 && s->session->ext.ecpointformats != NULL
826 && s->session->ext.ecpointformats_len > 0
827 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
828 /* we are using an ECC cipher */
830 unsigned char *list = s->session->ext.ecpointformats;
832 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
833 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
836 if (i == s->session->ext.ecpointformats_len) {
837 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
838 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
847 static int init_session_ticket(SSL *s, unsigned int context)
850 s->ext.ticket_expected = 0;
855 #ifndef OPENSSL_NO_OCSP
856 static int init_status_request(SSL *s, unsigned int context)
859 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
862 * Ensure we get sensible values passed to tlsext_status_cb in the event
863 * that we don't receive a status message
865 OPENSSL_free(s->ext.ocsp.resp);
866 s->ext.ocsp.resp = NULL;
867 s->ext.ocsp.resp_len = 0;
874 #ifndef OPENSSL_NO_NEXTPROTONEG
875 static int init_npn(SSL *s, unsigned int context)
883 static int init_alpn(SSL *s, unsigned int context)
885 OPENSSL_free(s->s3->alpn_selected);
886 s->s3->alpn_selected = NULL;
887 s->s3->alpn_selected_len = 0;
889 OPENSSL_free(s->s3->alpn_proposed);
890 s->s3->alpn_proposed = NULL;
891 s->s3->alpn_proposed_len = 0;
896 static int final_alpn(SSL *s, unsigned int context, int sent, int *al)
898 const unsigned char *selected = NULL;
899 unsigned char selected_len = 0;
904 if (s->ctx->ext.alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
905 int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len,
906 s->s3->alpn_proposed,
907 (unsigned int)s->s3->alpn_proposed_len,
908 s->ctx->ext.alpn_select_cb_arg);
910 if (r == SSL_TLSEXT_ERR_OK) {
911 OPENSSL_free(s->s3->alpn_selected);
912 s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
913 if (s->s3->alpn_selected == NULL) {
914 *al = SSL_AD_INTERNAL_ERROR;
917 s->s3->alpn_selected_len = selected_len;
918 #ifndef OPENSSL_NO_NEXTPROTONEG
919 /* ALPN takes precedence over NPN. */
922 } else if (r == SSL_TLSEXT_ERR_NOACK) {
923 /* Behave as if no callback was present. */
926 *al = SSL_AD_NO_APPLICATION_PROTOCOL;
934 static int init_sig_algs(SSL *s, unsigned int context)
936 /* Clear any signature algorithms extension received */
937 OPENSSL_free(s->s3->tmp.peer_sigalgs);
938 s->s3->tmp.peer_sigalgs = NULL;
943 #ifndef OPENSSL_NO_SRP
944 static int init_srp(SSL *s, unsigned int context)
946 OPENSSL_free(s->srp_ctx.login);
947 s->srp_ctx.login = NULL;
953 static int init_etm(SSL *s, unsigned int context)
960 static int init_ems(SSL *s, unsigned int context)
963 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
968 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
970 if (!s->server && s->hit) {
972 * Check extended master secret extension is consistent with
975 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
976 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
977 *al = SSL_AD_HANDSHAKE_FAILURE;
978 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
986 static int init_certificate_authorities(SSL *s, unsigned int context)
988 sk_X509_NAME_pop_free(s->s3->tmp.peer_ca_names, X509_NAME_free);
989 s->s3->tmp.peer_ca_names = NULL;
993 static int tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
994 unsigned int context, X509 *x,
995 size_t chainidx, int *al)
997 const STACK_OF(X509_NAME) *ca_sk = SSL_get0_CA_list(s);
999 if (ca_sk == NULL || sk_X509_NAME_num(ca_sk) == 0)
1002 if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_certificate_authorities)
1003 || !WPACKET_start_sub_packet_u16(pkt)
1004 || !construct_ca_names(s, pkt)
1005 || !WPACKET_close(pkt)) {
1006 SSLerr(SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,
1007 ERR_R_INTERNAL_ERROR);
1014 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
1015 unsigned int context, X509 *x,
1016 size_t chainidx, int *al)
1018 if (!parse_ca_names(s, pkt, al))
1020 if (PACKET_remaining(pkt) != 0) {
1021 *al = SSL_AD_DECODE_ERROR;
1027 #ifndef OPENSSL_NO_SRTP
1028 static int init_srtp(SSL *s, unsigned int context)
1031 s->srtp_profile = NULL;
1037 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
1039 if (!sent && SSL_IS_TLS13(s)) {
1040 *al = TLS13_AD_MISSING_EXTENSION;
1041 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
1048 #ifndef OPENSSL_NO_EC
1049 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
1051 if (!SSL_IS_TLS13(s))
1058 * we have no key_share
1060 * (we are not resuming
1061 * OR the kex_mode doesn't allow non key_share resumes)
1068 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
1069 /* Nothing left we can do - just fail */
1070 *al = SSL_AD_HANDSHAKE_FAILURE;
1071 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1078 * we have no key_share
1081 * we didn't already send a HelloRetryRequest
1083 * the client sent a key_share extension
1085 * (we are not resuming
1086 * OR the kex_mode allows key_share resumes)
1088 * a shared group exists
1090 * send a HelloRetryRequest
1092 * we are not resuming
1094 * the kex_mode doesn't allow non key_share resumes
1098 if (s->server && s->s3->peer_tmp == NULL) {
1099 /* No suitable share */
1100 if (s->hello_retry_request == 0 && sent
1102 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1104 const unsigned char *pcurves, *pcurvestmp, *clntcurves;
1105 size_t num_curves, clnt_num_curves, i;
1106 unsigned int group_id = 0;
1108 /* Check if a shared group exists */
1110 /* Get the clients list of supported groups. */
1111 if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
1112 *al = SSL_AD_INTERNAL_ERROR;
1113 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1117 /* Get our list of available groups */
1118 if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
1119 *al = SSL_AD_INTERNAL_ERROR;
1120 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1124 /* Find the first group we allow that is also in client's list */
1125 for (i = 0, pcurvestmp = pcurves; i < num_curves;
1126 i++, pcurvestmp += 2) {
1127 group_id = bytestogroup(pcurvestmp);
1129 if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1))
1133 if (i < num_curves) {
1134 /* A shared group exists so send a HelloRetryRequest */
1135 s->s3->group_id = group_id;
1136 s->hello_retry_request = 1;
1141 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1142 /* Nothing left we can do - just fail */
1143 *al = SSL_AD_HANDSHAKE_FAILURE;
1144 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1149 /* We have a key_share so don't send any more HelloRetryRequest messages */
1151 s->hello_retry_request = 0;
1154 * For a client side resumption with no key_share we need to generate
1155 * the handshake secret (otherwise this is done during key_share
1158 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
1159 *al = SSL_AD_INTERNAL_ERROR;
1160 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1168 static int init_psk_kex_modes(SSL *s, unsigned int context)
1170 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1174 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1175 size_t binderoffset, const unsigned char *binderin,
1176 unsigned char *binderout,
1177 SSL_SESSION *sess, int sign)
1179 EVP_PKEY *mackey = NULL;
1180 EVP_MD_CTX *mctx = NULL;
1181 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1182 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1183 const char resumption_label[] = "resumption psk binder key";
1184 size_t bindersize, hashsize = EVP_MD_size(md);
1187 /* Generate the early_secret */
1188 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1189 sess->master_key_length,
1190 (unsigned char *)&s->early_secret)) {
1191 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1196 * Create the handshake hash for the binder key...the messages so far are
1199 mctx = EVP_MD_CTX_new();
1201 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1202 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1203 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1207 /* Generate the binder key */
1208 if (!tls13_hkdf_expand(s, md, s->early_secret,
1209 (unsigned char *)resumption_label,
1210 sizeof(resumption_label) - 1, hash, binderkey,
1212 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1216 /* Generate the finished key */
1217 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1218 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1222 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1223 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1228 * Get a hash of the ClientHello up to the start of the binders. If we are
1229 * following a HelloRetryRequest then this includes the hash of the first
1230 * ClientHello and the HelloRetryRequest itself.
1232 if (s->hello_retry_request) {
1236 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
1237 if (hdatalen <= 0) {
1238 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_HANDSHAKE_LENGTH);
1243 * For servers the handshake buffer data will include the second
1244 * ClientHello - which we don't want - so we need to take that bit off.
1247 PACKET hashprefix, msg;
1249 /* Find how many bytes are left after the first two messages */
1250 if (!PACKET_buf_init(&hashprefix, hdata, hdatalen)
1251 || !PACKET_forward(&hashprefix, 1)
1252 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)
1253 || !PACKET_forward(&hashprefix, 1)
1254 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)) {
1255 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1258 hdatalen -= PACKET_remaining(&hashprefix);
1261 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1262 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1267 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1268 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1269 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1273 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1274 if (mackey == NULL) {
1275 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1280 binderout = tmpbinder;
1282 bindersize = hashsize;
1283 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1284 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1285 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1286 || bindersize != hashsize) {
1287 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1294 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1295 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1299 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1300 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1301 EVP_PKEY_free(mackey);
1302 EVP_MD_CTX_free(mctx);
1307 static int final_early_data(SSL *s, unsigned int context, int sent, int *al)
1309 if (!s->server || !sent)
1312 if (s->max_early_data == 0
1314 || s->session->ext.tick_identity != 0
1315 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
1316 || !s->ext.early_data_ok
1317 || s->hello_retry_request
1318 || s->s3->alpn_selected_len != s->session->ext.alpn_selected_len
1319 || (s->s3->alpn_selected_len > 0
1320 && memcmp(s->s3->alpn_selected, s->session->ext.alpn_selected,
1321 s->s3->alpn_selected_len) != 0)) {
1322 s->ext.early_data = SSL_EARLY_DATA_REJECTED;
1324 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;
1326 if (!tls13_change_cipher_state(s,
1327 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) {
1328 *al = SSL_AD_INTERNAL_ERROR;