2 * Copyright 2016-2017 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 init_sig_algs(SSL *s, unsigned int context);
32 static int init_certificate_authorities(SSL *s, unsigned int context);
33 static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
38 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
39 unsigned int context, X509 *x,
40 size_t chainidx, int *al);
41 #ifndef OPENSSL_NO_SRP
42 static int init_srp(SSL *s, unsigned int context);
44 static int init_etm(SSL *s, unsigned int context);
45 static int init_ems(SSL *s, unsigned int context);
46 static int final_ems(SSL *s, unsigned int context, int sent, int *al);
47 static int init_psk_kex_modes(SSL *s, unsigned int context);
49 static int final_key_share(SSL *s, unsigned int context, int sent, int *al);
51 #ifndef OPENSSL_NO_SRTP
52 static int init_srtp(SSL *s, unsigned int context);
54 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al);
55 static int final_early_data(SSL *s, unsigned int context, int sent, int *al);
57 /* Structure to define a built-in extension */
58 typedef struct extensions_definition_st {
59 /* The defined type for the extension */
62 * The context that this extension applies to, e.g. what messages and
67 * Initialise extension before parsing. Always called for relevant contexts
68 * even if extension not present
70 int (*init)(SSL *s, unsigned int context);
71 /* Parse extension sent from client to server */
72 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
73 size_t chainidx, int *al);
74 /* Parse extension send from server to client */
75 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
76 size_t chainidx, int *al);
77 /* Construct extension sent from server to client */
78 EXT_RETURN (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context,
79 X509 *x, size_t chainidx, int *al);
80 /* Construct extension sent from client to server */
81 EXT_RETURN (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context,
82 X509 *x, size_t chainidx, int *al);
84 * Finalise extension after parsing. Always called where an extensions was
85 * initialised even if the extension was not present. |sent| is set to 1 if
86 * the extension was seen, or 0 otherwise.
88 int (*final)(SSL *s, unsigned int context, int sent, int *al);
89 } EXTENSION_DEFINITION;
92 * Definitions of all built-in extensions. NOTE: Changes in the number or order
93 * of these extensions should be mirrored with equivalent changes to the
94 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
95 * Each extension has an initialiser, a client and
96 * server side parser and a finaliser. The initialiser is called (if the
97 * extension is relevant to the given context) even if we did not see the
98 * extension in the message that we received. The parser functions are only
99 * called if we see the extension in the message. The finalisers are always
100 * called if the initialiser was called.
101 * There are also server and client side constructor functions which are always
102 * called during message construction if the extension is relevant for the
104 * The initialisation, parsing, finalisation and construction functions are
105 * always called in the order defined in this list. Some extensions may depend
106 * on others having been processed first, so the order of this list is
108 * The extension context is defined by a series of flags which specify which
109 * messages the extension is relevant to. These flags also specify whether the
110 * extension is relevant to a particular protocol or protocol version.
112 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
114 * NOTE: WebSphere Application Server 7+ cannot handle empty extensions at
115 * the end, keep these extensions before signature_algorithm.
117 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
118 static const EXTENSION_DEFINITION ext_defs[] = {
120 TLSEXT_TYPE_renegotiate,
121 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
122 | SSL_EXT_SSL3_ALLOWED | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
123 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
124 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
128 TLSEXT_TYPE_server_name,
129 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
130 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
132 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
133 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
136 #ifndef OPENSSL_NO_SRP
139 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
140 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
145 #ifndef OPENSSL_NO_EC
147 TLSEXT_TYPE_ec_point_formats,
148 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
149 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
150 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
151 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
155 TLSEXT_TYPE_supported_groups,
156 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
157 NULL, tls_parse_ctos_supported_groups, NULL,
158 tls_construct_stoc_supported_groups,
159 tls_construct_ctos_supported_groups, NULL
166 TLSEXT_TYPE_session_ticket,
167 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
168 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
169 init_session_ticket, tls_parse_ctos_session_ticket,
170 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
171 tls_construct_ctos_session_ticket, NULL
173 #ifndef OPENSSL_NO_OCSP
175 TLSEXT_TYPE_status_request,
176 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
177 | SSL_EXT_TLS1_3_CERTIFICATE,
178 init_status_request, tls_parse_ctos_status_request,
179 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
180 tls_construct_ctos_status_request, NULL
185 #ifndef OPENSSL_NO_NEXTPROTONEG
187 TLSEXT_TYPE_next_proto_neg,
188 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
189 | SSL_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 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
203 | SSL_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, NULL
207 #ifndef OPENSSL_NO_SRTP
209 TLSEXT_TYPE_use_srtp,
210 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
211 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS | SSL_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 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
221 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
222 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
223 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
225 #ifndef OPENSSL_NO_CT
227 TLSEXT_TYPE_signed_certificate_timestamp,
228 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
229 | SSL_EXT_TLS1_3_CERTIFICATE,
232 * No server side support for this, but can be provided by a custom
233 * extension. This is an exception to the rule that custom extensions
234 * cannot override built in ones.
236 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
242 TLSEXT_TYPE_extended_master_secret,
243 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
244 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
245 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
246 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
249 TLSEXT_TYPE_signature_algorithms,
250 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
251 init_sig_algs, tls_parse_ctos_sig_algs,
252 tls_parse_ctos_sig_algs, tls_construct_ctos_sig_algs,
253 tls_construct_ctos_sig_algs, final_sig_algs
256 TLSEXT_TYPE_supported_versions,
257 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY
258 | SSL_EXT_TLS1_3_ONLY,
260 /* Processed inline as part of version selection */
261 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
264 TLSEXT_TYPE_psk_kex_modes,
265 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY
266 | SSL_EXT_TLS1_3_ONLY,
267 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
268 tls_construct_ctos_psk_kex_modes, NULL
270 #ifndef OPENSSL_NO_EC
273 * Must be in this list after supported_groups. We need that to have
274 * been parsed before we do this one.
276 TLSEXT_TYPE_key_share,
277 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
278 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY
279 | SSL_EXT_TLS1_3_ONLY,
280 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
281 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
287 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
288 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
289 NULL, NULL, tls_parse_stoc_cookie, NULL, tls_construct_ctos_cookie,
294 * Special unsolicited ServerHello extension only used when
295 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
297 TLSEXT_TYPE_cryptopro_bug,
298 SSL_EXT_TLS1_2_SERVER_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
299 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
302 TLSEXT_TYPE_early_data,
303 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
304 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
305 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data,
306 tls_construct_stoc_early_data, tls_construct_ctos_early_data,
310 TLSEXT_TYPE_certificate_authorities,
311 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
312 | SSL_EXT_TLS1_3_ONLY,
313 init_certificate_authorities,
314 tls_parse_certificate_authorities, tls_parse_certificate_authorities,
315 tls_construct_certificate_authorities,
316 tls_construct_certificate_authorities, NULL,
319 /* Must be immediately before pre_shared_key */
321 SSL_EXT_CLIENT_HELLO,
323 /* We send this, but don't read it */
324 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
327 /* Required by the TLSv1.3 spec to always be the last extension */
329 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
330 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
331 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
332 tls_construct_ctos_psk, NULL
336 /* Check whether an extension's context matches the current context */
337 static int validate_context(SSL *s, unsigned int extctx, unsigned int thisctx)
339 /* Check we're allowed to use this extension in this context */
340 if ((thisctx & extctx) == 0)
343 if (SSL_IS_DTLS(s)) {
344 if ((extctx & SSL_EXT_TLS_ONLY) != 0)
346 } else if ((extctx & SSL_EXT_DTLS_ONLY) != 0) {
354 * Verify whether we are allowed to use the extension |type| in the current
355 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
356 * indicate the extension is not allowed. If returning 1 then |*found| is set to
357 * the definition for the extension we found.
359 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
360 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
361 RAW_EXTENSION **found)
364 size_t builtin_num = OSSL_NELEM(ext_defs);
365 const EXTENSION_DEFINITION *thisext;
367 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
368 if (type == thisext->type) {
369 if (!validate_context(s, thisext->context, context))
372 *found = &rawexlist[i];
377 /* Check the custom extensions */
380 ENDPOINT role = ENDPOINT_BOTH;
381 custom_ext_method *meth = NULL;
383 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
384 role = ENDPOINT_SERVER;
385 else if ((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0)
386 role = ENDPOINT_CLIENT;
388 meth = custom_ext_find(meths, role, type, &offset);
390 if (!validate_context(s, meth->context, context))
392 *found = &rawexlist[offset + builtin_num];
397 /* Unknown extension. We allow it */
403 * Check whether the context defined for an extension |extctx| means whether
404 * the extension is relevant for the current context |thisctx| or not. Returns
405 * 1 if the extension is relevant for this context, and 0 otherwise
407 int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx)
410 && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0)
411 || (s->version == SSL3_VERSION
412 && (extctx & SSL_EXT_SSL3_ALLOWED) == 0)
414 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
415 || (!SSL_IS_TLS13(s) && (extctx & SSL_EXT_TLS1_3_ONLY) != 0)
416 || (s->hit && (extctx & SSL_EXT_IGNORE_ON_RESUMPTION) != 0))
423 * Gather a list of all the extensions from the data in |packet]. |context|
424 * tells us which message this extension is for. The raw extension data is
425 * stored in |*res| on success. In the event of an error the alert type to use
426 * is stored in |*al|. We don't actually process the content of the extensions
427 * yet, except to check their types. This function also runs the initialiser
428 * functions for all known extensions if |init| is nonzero (whether we have
429 * collected them or not). If successful the caller is responsible for freeing
430 * the contents of |*res|.
432 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
433 * more than one extension of the same type in a ClientHello or ServerHello.
434 * This function returns 1 if all extensions are unique and we have parsed their
435 * types, and 0 if the extensions contain duplicates, could not be successfully
436 * found, or an internal error occurred. We only check duplicates for
437 * extensions that we know about. We ignore others.
439 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
440 RAW_EXTENSION **res, int *al, size_t *len,
443 PACKET extensions = *packet;
446 custom_ext_methods *exts = &s->cert->custext;
447 RAW_EXTENSION *raw_extensions = NULL;
448 const EXTENSION_DEFINITION *thisexd;
453 * Initialise server side custom extensions. Client side is done during
454 * construction of extensions for the ClientHello.
456 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
457 custom_ext_init(&s->cert->custext);
459 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
460 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
461 if (raw_extensions == NULL) {
462 *al = SSL_AD_INTERNAL_ERROR;
463 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
468 while (PACKET_remaining(&extensions) > 0) {
469 unsigned int type, idx;
471 RAW_EXTENSION *thisex;
473 if (!PACKET_get_net_2(&extensions, &type) ||
474 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
475 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
476 *al = SSL_AD_DECODE_ERROR;
480 * Verify this extension is allowed. We only check duplicates for
481 * extensions that we recognise. We also have a special case for the
482 * PSK extension, which must be the last one in the ClientHello.
484 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
485 || (thisex != NULL && thisex->present == 1)
486 || (type == TLSEXT_TYPE_psk
487 && (context & SSL_EXT_CLIENT_HELLO) != 0
488 && PACKET_remaining(&extensions) != 0)) {
489 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
490 *al = SSL_AD_ILLEGAL_PARAMETER;
493 idx = thisex - raw_extensions;
495 * Check that we requested this extension (if appropriate). Requests can
496 * be sent in the ClientHello and CertificateRequest. Unsolicited
497 * extensions can be sent in the NewSessionTicket. We only do this for
498 * the built-in extensions. Custom extensions have a different but
499 * similar check elsewhere.
501 * - The HRR cookie extension is unsolicited
502 * - The renegotiate extension is unsolicited (the client signals
503 * support via an SCSV)
504 * - The signed_certificate_timestamp extension can be provided by a
505 * custom extension or by the built-in version. We let the extension
506 * itself handle unsolicited response checks.
508 if (idx < OSSL_NELEM(ext_defs)
509 && (context & (SSL_EXT_CLIENT_HELLO
510 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
511 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) == 0
512 && type != TLSEXT_TYPE_cookie
513 && type != TLSEXT_TYPE_renegotiate
514 && type != TLSEXT_TYPE_signed_certificate_timestamp
515 && (s->ext.extflags[idx] & SSL_EXT_FLAG_SENT) == 0) {
516 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_UNSOLICITED_EXTENSION);
517 *al = SSL_AD_UNSUPPORTED_EXTENSION;
520 if (thisex != NULL) {
521 thisex->data = extension;
524 thisex->received_order = i++;
526 s->ext.debug_cb(s, !s->server, thisex->type,
527 PACKET_data(&thisex->data),
528 PACKET_remaining(&thisex->data),
535 * Initialise all known extensions relevant to this context,
536 * whether we have found them or not
538 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs);
540 if (thisexd->init != NULL && (thisexd->context & context) != 0
541 && extension_is_relevant(s, thisexd->context, context)
542 && !thisexd->init(s, context)) {
543 *al = SSL_AD_INTERNAL_ERROR;
549 *res = raw_extensions;
555 OPENSSL_free(raw_extensions);
560 * Runs the parser for a given extension with index |idx|. |exts| contains the
561 * list of all parsed extensions previously collected by
562 * tls_collect_extensions(). The parser is only run if it is applicable for the
563 * given |context| and the parser has not already been run. If this is for a
564 * Certificate message, then we also provide the parser with the relevant
565 * Certificate |x| and its position in the |chainidx| with 0 being the first
566 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
567 * |*al| is populated with a suitable alert code. If an extension is not present
568 * this counted as success.
570 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
571 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
573 RAW_EXTENSION *currext = &exts[idx];
574 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
575 size_t chainidx, int *al) = NULL;
577 /* Skip if the extension is not present */
578 if (!currext->present)
581 /* Skip if we've already parsed this extension */
587 if (idx < OSSL_NELEM(ext_defs)) {
588 /* We are handling a built-in extension */
589 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
591 /* Check if extension is defined for our protocol. If not, skip */
592 if (!extension_is_relevant(s, extdef->context, context))
595 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
598 return parser(s, &currext->data, context, x, chainidx, al);
601 * If the parser is NULL we fall through to the custom extension
606 /* Parse custom extensions */
607 if (custom_ext_parse(s, context, currext->type,
608 PACKET_data(&currext->data),
609 PACKET_remaining(&currext->data),
610 x, chainidx, al) <= 0)
617 * Parse all remaining extensions that have not yet been parsed. Also calls the
618 * finalisation for all extensions at the end if |fin| is nonzero, whether we
619 * collected them or not. Returns 1 for success or 0 for failure. If we are
620 * working on a Certificate message then we also pass the Certificate |x| and
621 * its position in the |chainidx|, with 0 being the first certificate. On
622 * failure, |*al| is populated with a suitable alert code.
624 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
625 size_t chainidx, int *al, int fin)
627 size_t i, numexts = OSSL_NELEM(ext_defs);
628 const EXTENSION_DEFINITION *thisexd;
630 /* Calculate the number of extensions in the extensions list */
631 numexts += s->cert->custext.meths_count;
633 /* Parse each extension in turn */
634 for (i = 0; i < numexts; i++) {
635 if (!tls_parse_extension(s, i, context, exts, x, chainidx, al))
641 * Finalise all known extensions relevant to this context,
642 * whether we have found them or not
644 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs);
646 if (thisexd->final != NULL && (thisexd->context & context) != 0
647 && !thisexd->final(s, context, exts[i].present, al))
655 int should_add_extension(SSL *s, unsigned int extctx, unsigned int thisctx,
658 /* Skip if not relevant for our context */
659 if ((extctx & thisctx) == 0)
662 /* Check if this extension is defined for our protocol. If not, skip */
663 if ((SSL_IS_DTLS(s) && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0)
664 || (s->version == SSL3_VERSION
665 && (extctx & SSL_EXT_SSL3_ALLOWED) == 0)
667 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
669 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0
670 && (thisctx & SSL_EXT_CLIENT_HELLO) == 0)
671 || ((extctx & SSL_EXT_TLS1_3_ONLY) != 0
672 && (thisctx & SSL_EXT_CLIENT_HELLO) != 0
673 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION)))
680 * Construct all the extensions relevant to the current |context| and write
681 * them to |pkt|. If this is an extension for a Certificate in a Certificate
682 * message, then |x| will be set to the Certificate we are handling, and
683 * |chainidx| will indicate the position in the chainidx we are processing (with
684 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
685 * failure occurs then |al| is populated with a suitable alert code. On a
686 * failure construction stops at the first extension to fail to construct.
688 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
689 X509 *x, size_t chainidx, int *al)
692 int min_version, max_version = 0, reason, tmpal;
693 const EXTENSION_DEFINITION *thisexd;
696 * Normally if something goes wrong during construction it's an internal
697 * error. We can always override this later.
699 tmpal = SSL_AD_INTERNAL_ERROR;
701 if (!WPACKET_start_sub_packet_u16(pkt)
703 * If extensions are of zero length then we don't even add the
704 * extensions length bytes to a ClientHello/ServerHello in SSLv3
707 (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0
708 && s->version == SSL3_VERSION
709 && !WPACKET_set_flags(pkt,
710 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
711 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
715 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
716 reason = ssl_get_min_max_version(s, &min_version, &max_version);
718 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
723 /* Add custom extensions first */
724 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
725 /* On the server side with initialise during ClientHello parsing */
726 custom_ext_init(&s->cert->custext);
728 if (!custom_ext_add(s, context, pkt, x, chainidx, max_version, &tmpal)) {
729 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
733 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
734 EXT_RETURN (*construct)(SSL *s, WPACKET *pkt, unsigned int context,
735 X509 *x, size_t chainidx, int *al);
738 /* Skip if not relevant for our context */
739 if (!should_add_extension(s, thisexd->context, context, max_version))
742 construct = s->server ? thisexd->construct_stoc
743 : thisexd->construct_ctos;
745 if (construct == NULL)
748 ret = construct(s, pkt, context, x, chainidx, &tmpal);
749 if (ret == EXT_RETURN_FAIL)
751 if (ret == EXT_RETURN_SENT
752 && (context & (SSL_EXT_CLIENT_HELLO
753 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
754 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) != 0)
755 s->ext.extflags[i] |= SSL_EXT_FLAG_SENT;
758 if (!WPACKET_close(pkt)) {
759 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
771 * Built in extension finalisation and initialisation functions. All initialise
772 * or finalise the associated extension type for the given |context|. For
773 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
774 * otherwise. These functions return 1 on success or 0 on failure. In the event
775 * of a failure then |*al| is populated with a suitable error code.
778 static int final_renegotiate(SSL *s, unsigned int context, int sent,
783 * Check if we can connect to a server that doesn't support safe
786 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
787 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
789 *al = SSL_AD_HANDSHAKE_FAILURE;
790 SSLerr(SSL_F_FINAL_RENEGOTIATE,
791 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
798 /* Need RI if renegotiating */
800 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
802 *al = SSL_AD_HANDSHAKE_FAILURE;
803 SSLerr(SSL_F_FINAL_RENEGOTIATE,
804 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
812 static int init_server_name(SSL *s, unsigned int context)
815 s->servername_done = 0;
820 static int final_server_name(SSL *s, unsigned int context, int sent,
823 int ret = SSL_TLSEXT_ERR_NOACK;
824 int altmp = SSL_AD_UNRECOGNIZED_NAME;
826 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
827 ret = s->ctx->ext.servername_cb(s, &altmp,
828 s->ctx->ext.servername_arg);
829 else if (s->session_ctx != NULL
830 && s->session_ctx->ext.servername_cb != 0)
831 ret = s->session_ctx->ext.servername_cb(s, &altmp,
832 s->session_ctx->ext.servername_arg);
835 case SSL_TLSEXT_ERR_ALERT_FATAL:
839 case SSL_TLSEXT_ERR_ALERT_WARNING:
843 case SSL_TLSEXT_ERR_NOACK:
844 s->servername_done = 0;
852 #ifndef OPENSSL_NO_EC
853 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
856 unsigned long alg_k, alg_a;
861 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
862 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
865 * If we are client and using an elliptic curve cryptography cipher
866 * suite, then if server returns an EC point formats lists extension it
867 * must contain uncompressed.
869 if (s->ext.ecpointformats != NULL
870 && s->ext.ecpointformats_len > 0
871 && s->session->ext.ecpointformats != NULL
872 && s->session->ext.ecpointformats_len > 0
873 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
874 /* we are using an ECC cipher */
876 unsigned char *list = s->session->ext.ecpointformats;
878 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
879 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
882 if (i == s->session->ext.ecpointformats_len) {
883 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
884 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
893 static int init_session_ticket(SSL *s, unsigned int context)
896 s->ext.ticket_expected = 0;
901 #ifndef OPENSSL_NO_OCSP
902 static int init_status_request(SSL *s, unsigned int context)
905 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
908 * Ensure we get sensible values passed to tlsext_status_cb in the event
909 * that we don't receive a status message
911 OPENSSL_free(s->ext.ocsp.resp);
912 s->ext.ocsp.resp = NULL;
913 s->ext.ocsp.resp_len = 0;
920 #ifndef OPENSSL_NO_NEXTPROTONEG
921 static int init_npn(SSL *s, unsigned int context)
929 static int init_alpn(SSL *s, unsigned int context)
931 OPENSSL_free(s->s3->alpn_selected);
932 s->s3->alpn_selected = NULL;
933 s->s3->alpn_selected_len = 0;
935 OPENSSL_free(s->s3->alpn_proposed);
936 s->s3->alpn_proposed = NULL;
937 s->s3->alpn_proposed_len = 0;
942 static int init_sig_algs(SSL *s, unsigned int context)
944 /* Clear any signature algorithms extension received */
945 OPENSSL_free(s->s3->tmp.peer_sigalgs);
946 s->s3->tmp.peer_sigalgs = NULL;
951 #ifndef OPENSSL_NO_SRP
952 static int init_srp(SSL *s, unsigned int context)
954 OPENSSL_free(s->srp_ctx.login);
955 s->srp_ctx.login = NULL;
961 static int init_etm(SSL *s, unsigned int context)
968 static int init_ems(SSL *s, unsigned int context)
971 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
976 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
978 if (!s->server && s->hit) {
980 * Check extended master secret extension is consistent with
983 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
984 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
985 *al = SSL_AD_HANDSHAKE_FAILURE;
986 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
994 static int init_certificate_authorities(SSL *s, unsigned int context)
996 sk_X509_NAME_pop_free(s->s3->tmp.peer_ca_names, X509_NAME_free);
997 s->s3->tmp.peer_ca_names = NULL;
1001 static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
1002 unsigned int context,
1007 const STACK_OF(X509_NAME) *ca_sk = SSL_get0_CA_list(s);
1009 if (ca_sk == NULL || sk_X509_NAME_num(ca_sk) == 0)
1010 return EXT_RETURN_NOT_SENT;
1012 if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_certificate_authorities)
1013 || !WPACKET_start_sub_packet_u16(pkt)
1014 || !construct_ca_names(s, pkt)
1015 || !WPACKET_close(pkt)) {
1016 SSLerr(SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,
1017 ERR_R_INTERNAL_ERROR);
1018 return EXT_RETURN_FAIL;
1021 return EXT_RETURN_SENT;
1024 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
1025 unsigned int context, X509 *x,
1026 size_t chainidx, int *al)
1028 if (!parse_ca_names(s, pkt, al))
1030 if (PACKET_remaining(pkt) != 0) {
1031 *al = SSL_AD_DECODE_ERROR;
1037 #ifndef OPENSSL_NO_SRTP
1038 static int init_srtp(SSL *s, unsigned int context)
1041 s->srtp_profile = NULL;
1047 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
1049 if (!sent && SSL_IS_TLS13(s) && !s->hit) {
1050 *al = TLS13_AD_MISSING_EXTENSION;
1051 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
1058 #ifndef OPENSSL_NO_EC
1059 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
1061 if (!SSL_IS_TLS13(s))
1064 /* Nothing to do for key_share in an HRR */
1065 if ((context & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0)
1072 * we have no key_share
1074 * (we are not resuming
1075 * OR the kex_mode doesn't allow non key_share resumes)
1082 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
1083 /* Nothing left we can do - just fail */
1084 *al = SSL_AD_MISSING_EXTENSION;
1085 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1092 * we have no key_share
1095 * we didn't already send a HelloRetryRequest
1097 * the client sent a key_share extension
1099 * (we are not resuming
1100 * OR the kex_mode allows key_share resumes)
1102 * a shared group exists
1104 * send a HelloRetryRequest
1106 * we are not resuming
1108 * the kex_mode doesn't allow non key_share resumes
1112 if (s->server && s->s3->peer_tmp == NULL) {
1113 /* No suitable share */
1114 if (s->hello_retry_request == 0 && sent
1116 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1118 const unsigned char *pcurves, *pcurvestmp, *clntcurves;
1119 size_t num_curves, clnt_num_curves, i;
1120 unsigned int group_id = 0;
1122 /* Check if a shared group exists */
1124 /* Get the clients list of supported groups. */
1125 if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
1126 *al = SSL_AD_INTERNAL_ERROR;
1127 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1131 /* Get our list of available groups */
1132 if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
1133 *al = SSL_AD_INTERNAL_ERROR;
1134 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1138 /* Find the first group we allow that is also in client's list */
1139 for (i = 0, pcurvestmp = pcurves; i < num_curves;
1140 i++, pcurvestmp += 2) {
1141 group_id = bytestogroup(pcurvestmp);
1143 if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1))
1147 if (i < num_curves) {
1148 /* A shared group exists so send a HelloRetryRequest */
1149 s->s3->group_id = group_id;
1150 s->hello_retry_request = 1;
1155 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1156 /* Nothing left we can do - just fail */
1158 *al = SSL_AD_MISSING_EXTENSION;
1160 *al = SSL_AD_HANDSHAKE_FAILURE;
1161 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1166 /* We have a key_share so don't send any more HelloRetryRequest messages */
1168 s->hello_retry_request = 0;
1171 * For a client side resumption with no key_share we need to generate
1172 * the handshake secret (otherwise this is done during key_share
1175 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
1176 *al = SSL_AD_INTERNAL_ERROR;
1177 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1185 static int init_psk_kex_modes(SSL *s, unsigned int context)
1187 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1191 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1192 size_t binderoffset, const unsigned char *binderin,
1193 unsigned char *binderout, SSL_SESSION *sess, int sign,
1196 EVP_PKEY *mackey = NULL;
1197 EVP_MD_CTX *mctx = NULL;
1198 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1199 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1200 unsigned char tmppsk[EVP_MAX_MD_SIZE];
1201 unsigned char *early_secret, *psk;
1202 const char resumption_label[] = "res binder";
1203 const char external_label[] = "ext binder";
1204 const char nonce_label[] = "resumption";
1206 size_t bindersize, labelsize, hashsize = EVP_MD_size(md);
1210 label = external_label;
1211 labelsize = sizeof(external_label) - 1;
1213 label = resumption_label;
1214 labelsize = sizeof(resumption_label) - 1;
1217 if (sess->master_key_length != hashsize) {
1218 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_PSK);
1223 psk = sess->master_key;
1226 if (!tls13_hkdf_expand(s, md, sess->master_key,
1227 (const unsigned char *)nonce_label,
1228 sizeof(nonce_label) - 1, sess->ext.tick_nonce,
1229 sess->ext.tick_nonce_len, psk, hashsize)) {
1230 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1236 * Generate the early_secret. On the server side we've selected a PSK to
1237 * resume with (internal or external) so we always do this. On the client
1238 * side we do this for a non-external (i.e. resumption) PSK so that it
1239 * is in place for sending early data. For client side external PSK we
1240 * generate it but store it away for later use.
1242 if (s->server || !external)
1243 early_secret = (unsigned char *)s->early_secret;
1245 early_secret = (unsigned char *)sess->early_secret;
1246 if (!tls13_generate_secret(s, md, NULL, psk, hashsize, early_secret)) {
1247 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1252 * Create the handshake hash for the binder key...the messages so far are
1255 mctx = EVP_MD_CTX_new();
1257 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1258 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1259 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1263 /* Generate the binder key */
1264 if (!tls13_hkdf_expand(s, md, early_secret, (unsigned char *)label,
1265 labelsize, hash, hashsize, binderkey, hashsize)) {
1266 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1270 /* Generate the finished key */
1271 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1272 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1276 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1277 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1282 * Get a hash of the ClientHello up to the start of the binders. If we are
1283 * following a HelloRetryRequest then this includes the hash of the first
1284 * ClientHello and the HelloRetryRequest itself.
1286 if (s->hello_retry_request) {
1290 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
1291 if (hdatalen <= 0) {
1292 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_HANDSHAKE_LENGTH);
1297 * For servers the handshake buffer data will include the second
1298 * ClientHello - which we don't want - so we need to take that bit off.
1301 PACKET hashprefix, msg;
1303 /* Find how many bytes are left after the first two messages */
1304 if (!PACKET_buf_init(&hashprefix, hdata, hdatalen)
1305 || !PACKET_forward(&hashprefix, 1)
1306 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)
1307 || !PACKET_forward(&hashprefix, 1)
1308 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)) {
1309 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1312 hdatalen -= PACKET_remaining(&hashprefix);
1315 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1316 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1321 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1322 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1323 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1327 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1328 if (mackey == NULL) {
1329 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1334 binderout = tmpbinder;
1336 bindersize = hashsize;
1337 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1338 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1339 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1340 || bindersize != hashsize) {
1341 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1348 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1349 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1353 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1354 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1355 EVP_PKEY_free(mackey);
1356 EVP_MD_CTX_free(mctx);
1361 static int final_early_data(SSL *s, unsigned int context, int sent, int *al)
1363 if (!s->server || !sent)
1366 if (s->max_early_data == 0
1368 || s->session->ext.tick_identity != 0
1369 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
1370 || !s->ext.early_data_ok
1371 || s->hello_retry_request
1372 || s->s3->alpn_selected_len != s->session->ext.alpn_selected_len
1373 || (s->s3->alpn_selected_len > 0
1374 && memcmp(s->s3->alpn_selected, s->session->ext.alpn_selected,
1375 s->s3->alpn_selected_len) != 0)) {
1376 s->ext.early_data = SSL_EARLY_DATA_REJECTED;
1378 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;
1380 if (!tls13_change_cipher_state(s,
1381 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) {
1382 *al = SSL_AD_INTERNAL_ERROR;