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 "internal/nelem.h"
12 #include "../ssl_locl.h"
13 #include "statem_locl.h"
15 static int final_renegotiate(SSL *s, unsigned int context, int sent,
17 static int init_server_name(SSL *s, unsigned int context);
18 static int final_server_name(SSL *s, unsigned int context, int sent,
21 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
24 static int init_session_ticket(SSL *s, unsigned int context);
25 #ifndef OPENSSL_NO_OCSP
26 static int init_status_request(SSL *s, unsigned int context);
28 #ifndef OPENSSL_NO_NEXTPROTONEG
29 static int init_npn(SSL *s, unsigned int context);
31 static int init_alpn(SSL *s, unsigned int context);
32 static int init_sig_algs(SSL *s, unsigned int context);
33 static int init_certificate_authorities(SSL *s, unsigned int context);
34 static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
39 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
40 unsigned int context, X509 *x,
41 size_t chainidx, int *al);
42 #ifndef OPENSSL_NO_SRP
43 static int init_srp(SSL *s, unsigned int context);
45 static int init_etm(SSL *s, unsigned int context);
46 static int init_ems(SSL *s, unsigned int context);
47 static int final_ems(SSL *s, unsigned int context, int sent, int *al);
48 static int init_psk_kex_modes(SSL *s, unsigned int context);
50 static int final_key_share(SSL *s, unsigned int context, int sent, int *al);
52 #ifndef OPENSSL_NO_SRTP
53 static int init_srtp(SSL *s, unsigned int context);
55 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al);
56 static int final_early_data(SSL *s, unsigned int context, int sent, int *al);
58 /* Structure to define a built-in extension */
59 typedef struct extensions_definition_st {
60 /* The defined type for the extension */
63 * The context that this extension applies to, e.g. what messages and
68 * Initialise extension before parsing. Always called for relevant contexts
69 * even if extension not present
71 int (*init)(SSL *s, unsigned int context);
72 /* Parse extension sent from client to server */
73 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
74 size_t chainidx, int *al);
75 /* Parse extension send from server to client */
76 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
77 size_t chainidx, int *al);
78 /* Construct extension sent from server to client */
79 EXT_RETURN (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context,
80 X509 *x, size_t chainidx, int *al);
81 /* Construct extension sent from client to server */
82 EXT_RETURN (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context,
83 X509 *x, size_t chainidx, int *al);
85 * Finalise extension after parsing. Always called where an extensions was
86 * initialised even if the extension was not present. |sent| is set to 1 if
87 * the extension was seen, or 0 otherwise.
89 int (*final)(SSL *s, unsigned int context, int sent, int *al);
90 } EXTENSION_DEFINITION;
93 * Definitions of all built-in extensions. NOTE: Changes in the number or order
94 * of these extensions should be mirrored with equivalent changes to the
95 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
96 * Each extension has an initialiser, a client and
97 * server side parser and a finaliser. The initialiser is called (if the
98 * extension is relevant to the given context) even if we did not see the
99 * extension in the message that we received. The parser functions are only
100 * called if we see the extension in the message. The finalisers are always
101 * called if the initialiser was called.
102 * There are also server and client side constructor functions which are always
103 * called during message construction if the extension is relevant for the
105 * The initialisation, parsing, finalisation and construction functions are
106 * always called in the order defined in this list. Some extensions may depend
107 * on others having been processed first, so the order of this list is
109 * The extension context is defined by a series of flags which specify which
110 * messages the extension is relevant to. These flags also specify whether the
111 * extension is relevant to a particular protocol or protocol version.
113 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
115 * NOTE: WebSphere Application Server 7+ cannot handle empty extensions at
116 * the end, keep these extensions before signature_algorithm.
118 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
119 static const EXTENSION_DEFINITION ext_defs[] = {
121 TLSEXT_TYPE_renegotiate,
122 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
123 | SSL_EXT_SSL3_ALLOWED | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
124 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
125 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
129 TLSEXT_TYPE_server_name,
130 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
131 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
133 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
134 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
137 #ifndef OPENSSL_NO_SRP
140 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
141 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
146 #ifndef OPENSSL_NO_EC
148 TLSEXT_TYPE_ec_point_formats,
149 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
150 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
151 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
152 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
156 TLSEXT_TYPE_supported_groups,
157 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
158 NULL, tls_parse_ctos_supported_groups, NULL,
159 tls_construct_stoc_supported_groups,
160 tls_construct_ctos_supported_groups, NULL
167 TLSEXT_TYPE_session_ticket,
168 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
169 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
170 init_session_ticket, tls_parse_ctos_session_ticket,
171 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
172 tls_construct_ctos_session_ticket, NULL
174 #ifndef OPENSSL_NO_OCSP
176 TLSEXT_TYPE_status_request,
177 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
178 | SSL_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 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
190 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
191 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
192 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
199 * Must appear in this list after server_name so that finalisation
200 * happens after server_name callbacks
202 TLSEXT_TYPE_application_layer_protocol_negotiation,
203 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
204 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
205 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
206 tls_construct_stoc_alpn, tls_construct_ctos_alpn, NULL
208 #ifndef OPENSSL_NO_SRTP
210 TLSEXT_TYPE_use_srtp,
211 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
212 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS | SSL_EXT_DTLS_ONLY,
213 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
214 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
220 TLSEXT_TYPE_encrypt_then_mac,
221 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
222 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
223 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
224 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
226 #ifndef OPENSSL_NO_CT
228 TLSEXT_TYPE_signed_certificate_timestamp,
229 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
230 | SSL_EXT_TLS1_3_CERTIFICATE,
233 * No server side support for this, but can be provided by a custom
234 * extension. This is an exception to the rule that custom extensions
235 * cannot override built in ones.
237 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
243 TLSEXT_TYPE_extended_master_secret,
244 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
245 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
246 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
247 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
250 TLSEXT_TYPE_signature_algorithms,
251 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
252 init_sig_algs, tls_parse_ctos_sig_algs,
253 tls_parse_ctos_sig_algs, tls_construct_ctos_sig_algs,
254 tls_construct_ctos_sig_algs, final_sig_algs
257 TLSEXT_TYPE_supported_versions,
258 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY
259 | SSL_EXT_TLS1_3_ONLY,
261 /* Processed inline as part of version selection */
262 NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL
265 TLSEXT_TYPE_psk_kex_modes,
266 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY
267 | SSL_EXT_TLS1_3_ONLY,
268 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
269 tls_construct_ctos_psk_kex_modes, NULL
271 #ifndef OPENSSL_NO_EC
274 * Must be in this list after supported_groups. We need that to have
275 * been parsed before we do this one.
277 TLSEXT_TYPE_key_share,
278 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
279 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY
280 | SSL_EXT_TLS1_3_ONLY,
281 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share,
282 tls_construct_stoc_key_share, tls_construct_ctos_key_share,
288 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
289 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
290 NULL, NULL, tls_parse_stoc_cookie, NULL, tls_construct_ctos_cookie,
295 * Special unsolicited ServerHello extension only used when
296 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
298 TLSEXT_TYPE_cryptopro_bug,
299 SSL_EXT_TLS1_2_SERVER_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
300 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
303 TLSEXT_TYPE_early_data,
304 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
305 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
306 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data,
307 tls_construct_stoc_early_data, tls_construct_ctos_early_data,
311 TLSEXT_TYPE_certificate_authorities,
312 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
313 | SSL_EXT_TLS1_3_ONLY,
314 init_certificate_authorities,
315 tls_parse_certificate_authorities, tls_parse_certificate_authorities,
316 tls_construct_certificate_authorities,
317 tls_construct_certificate_authorities, NULL,
320 /* Must be immediately before pre_shared_key */
322 SSL_EXT_CLIENT_HELLO,
324 /* We send this, but don't read it */
325 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
328 /* Required by the TLSv1.3 spec to always be the last extension */
330 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
331 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
332 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
333 tls_construct_ctos_psk, NULL
337 /* Check whether an extension's context matches the current context */
338 static int validate_context(SSL *s, unsigned int extctx, unsigned int thisctx)
340 /* Check we're allowed to use this extension in this context */
341 if ((thisctx & extctx) == 0)
344 if (SSL_IS_DTLS(s)) {
345 if ((extctx & SSL_EXT_TLS_ONLY) != 0)
347 } else if ((extctx & SSL_EXT_DTLS_ONLY) != 0) {
355 * Verify whether we are allowed to use the extension |type| in the current
356 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
357 * indicate the extension is not allowed. If returning 1 then |*found| is set to
358 * the definition for the extension we found.
360 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
361 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
362 RAW_EXTENSION **found)
365 size_t builtin_num = OSSL_NELEM(ext_defs);
366 const EXTENSION_DEFINITION *thisext;
368 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
369 if (type == thisext->type) {
370 if (!validate_context(s, thisext->context, context))
373 *found = &rawexlist[i];
378 /* Check the custom extensions */
381 ENDPOINT role = ENDPOINT_BOTH;
382 custom_ext_method *meth = NULL;
384 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
385 role = ENDPOINT_SERVER;
386 else if ((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0)
387 role = ENDPOINT_CLIENT;
389 meth = custom_ext_find(meths, role, type, &offset);
391 if (!validate_context(s, meth->context, context))
393 *found = &rawexlist[offset + builtin_num];
398 /* Unknown extension. We allow it */
404 * Check whether the context defined for an extension |extctx| means whether
405 * the extension is relevant for the current context |thisctx| or not. Returns
406 * 1 if the extension is relevant for this context, and 0 otherwise
408 int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx)
411 && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0)
412 || (s->version == SSL3_VERSION
413 && (extctx & SSL_EXT_SSL3_ALLOWED) == 0)
415 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
416 || (!SSL_IS_TLS13(s) && (extctx & SSL_EXT_TLS1_3_ONLY) != 0)
417 || (s->hit && (extctx & SSL_EXT_IGNORE_ON_RESUMPTION) != 0))
424 * Gather a list of all the extensions from the data in |packet]. |context|
425 * tells us which message this extension is for. The raw extension data is
426 * stored in |*res| on success. In the event of an error the alert type to use
427 * is stored in |*al|. We don't actually process the content of the extensions
428 * yet, except to check their types. This function also runs the initialiser
429 * functions for all known extensions if |init| is nonzero (whether we have
430 * collected them or not). If successful the caller is responsible for freeing
431 * the contents of |*res|.
433 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
434 * more than one extension of the same type in a ClientHello or ServerHello.
435 * This function returns 1 if all extensions are unique and we have parsed their
436 * types, and 0 if the extensions contain duplicates, could not be successfully
437 * found, or an internal error occurred. We only check duplicates for
438 * extensions that we know about. We ignore others.
440 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
441 RAW_EXTENSION **res, int *al, size_t *len,
444 PACKET extensions = *packet;
447 custom_ext_methods *exts = &s->cert->custext;
448 RAW_EXTENSION *raw_extensions = NULL;
449 const EXTENSION_DEFINITION *thisexd;
454 * Initialise server side custom extensions. Client side is done during
455 * construction of extensions for the ClientHello.
457 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
458 custom_ext_init(&s->cert->custext);
460 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
461 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
462 if (raw_extensions == NULL) {
463 *al = SSL_AD_INTERNAL_ERROR;
464 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE);
469 while (PACKET_remaining(&extensions) > 0) {
470 unsigned int type, idx;
472 RAW_EXTENSION *thisex;
474 if (!PACKET_get_net_2(&extensions, &type) ||
475 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
476 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
477 *al = SSL_AD_DECODE_ERROR;
481 * Verify this extension is allowed. We only check duplicates for
482 * extensions that we recognise. We also have a special case for the
483 * PSK extension, which must be the last one in the ClientHello.
485 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
486 || (thisex != NULL && thisex->present == 1)
487 || (type == TLSEXT_TYPE_psk
488 && (context & SSL_EXT_CLIENT_HELLO) != 0
489 && PACKET_remaining(&extensions) != 0)) {
490 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION);
491 *al = SSL_AD_ILLEGAL_PARAMETER;
494 idx = thisex - raw_extensions;
496 * Check that we requested this extension (if appropriate). Requests can
497 * be sent in the ClientHello and CertificateRequest. Unsolicited
498 * extensions can be sent in the NewSessionTicket. We only do this for
499 * the built-in extensions. Custom extensions have a different but
500 * similar check elsewhere.
502 * - The HRR cookie extension is unsolicited
503 * - The renegotiate extension is unsolicited (the client signals
504 * support via an SCSV)
505 * - The signed_certificate_timestamp extension can be provided by a
506 * custom extension or by the built-in version. We let the extension
507 * itself handle unsolicited response checks.
509 if (idx < OSSL_NELEM(ext_defs)
510 && (context & (SSL_EXT_CLIENT_HELLO
511 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
512 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) == 0
513 && type != TLSEXT_TYPE_cookie
514 && type != TLSEXT_TYPE_renegotiate
515 && type != TLSEXT_TYPE_signed_certificate_timestamp
516 && (s->ext.extflags[idx] & SSL_EXT_FLAG_SENT) == 0) {
517 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_UNSOLICITED_EXTENSION);
518 *al = SSL_AD_UNSUPPORTED_EXTENSION;
521 if (thisex != NULL) {
522 thisex->data = extension;
525 thisex->received_order = i++;
527 s->ext.debug_cb(s, !s->server, thisex->type,
528 PACKET_data(&thisex->data),
529 PACKET_remaining(&thisex->data),
536 * Initialise all known extensions relevant to this context,
537 * whether we have found them or not
539 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs);
541 if (thisexd->init != NULL && (thisexd->context & context) != 0
542 && extension_is_relevant(s, thisexd->context, context)
543 && !thisexd->init(s, context)) {
544 *al = SSL_AD_INTERNAL_ERROR;
550 *res = raw_extensions;
556 OPENSSL_free(raw_extensions);
561 * Runs the parser for a given extension with index |idx|. |exts| contains the
562 * list of all parsed extensions previously collected by
563 * tls_collect_extensions(). The parser is only run if it is applicable for the
564 * given |context| and the parser has not already been run. If this is for a
565 * Certificate message, then we also provide the parser with the relevant
566 * Certificate |x| and its position in the |chainidx| with 0 being the first
567 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
568 * |*al| is populated with a suitable alert code. If an extension is not present
569 * this counted as success.
571 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
572 RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al)
574 RAW_EXTENSION *currext = &exts[idx];
575 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
576 size_t chainidx, int *al) = NULL;
578 /* Skip if the extension is not present */
579 if (!currext->present)
582 /* Skip if we've already parsed this extension */
588 if (idx < OSSL_NELEM(ext_defs)) {
589 /* We are handling a built-in extension */
590 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
592 /* Check if extension is defined for our protocol. If not, skip */
593 if (!extension_is_relevant(s, extdef->context, context))
596 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
599 return parser(s, &currext->data, context, x, chainidx, al);
602 * If the parser is NULL we fall through to the custom extension
607 /* Parse custom extensions */
608 if (custom_ext_parse(s, context, currext->type,
609 PACKET_data(&currext->data),
610 PACKET_remaining(&currext->data),
611 x, chainidx, al) <= 0)
618 * Parse all remaining extensions that have not yet been parsed. Also calls the
619 * finalisation for all extensions at the end if |fin| is nonzero, whether we
620 * collected them or not. Returns 1 for success or 0 for failure. If we are
621 * working on a Certificate message then we also pass the Certificate |x| and
622 * its position in the |chainidx|, with 0 being the first certificate. On
623 * failure, |*al| is populated with a suitable alert code.
625 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
626 size_t chainidx, int *al, int fin)
628 size_t i, numexts = OSSL_NELEM(ext_defs);
629 const EXTENSION_DEFINITION *thisexd;
631 /* Calculate the number of extensions in the extensions list */
632 numexts += s->cert->custext.meths_count;
634 /* Parse each extension in turn */
635 for (i = 0; i < numexts; i++) {
636 if (!tls_parse_extension(s, i, context, exts, x, chainidx, al))
642 * Finalise all known extensions relevant to this context,
643 * whether we have found them or not
645 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs);
647 if (thisexd->final != NULL && (thisexd->context & context) != 0
648 && !thisexd->final(s, context, exts[i].present, al))
656 int should_add_extension(SSL *s, unsigned int extctx, unsigned int thisctx,
659 /* Skip if not relevant for our context */
660 if ((extctx & thisctx) == 0)
663 /* Check if this extension is defined for our protocol. If not, skip */
664 if ((SSL_IS_DTLS(s) && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0)
665 || (s->version == SSL3_VERSION
666 && (extctx & SSL_EXT_SSL3_ALLOWED) == 0)
668 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
670 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0
671 && (thisctx & SSL_EXT_CLIENT_HELLO) == 0)
672 || ((extctx & SSL_EXT_TLS1_3_ONLY) != 0
673 && (thisctx & SSL_EXT_CLIENT_HELLO) != 0
674 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION)))
681 * Construct all the extensions relevant to the current |context| and write
682 * them to |pkt|. If this is an extension for a Certificate in a Certificate
683 * message, then |x| will be set to the Certificate we are handling, and
684 * |chainidx| will indicate the position in the chainidx we are processing (with
685 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
686 * failure occurs then |al| is populated with a suitable alert code. On a
687 * failure construction stops at the first extension to fail to construct.
689 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
690 X509 *x, size_t chainidx, int *al)
693 int min_version, max_version = 0, reason, tmpal;
694 const EXTENSION_DEFINITION *thisexd;
697 * Normally if something goes wrong during construction it's an internal
698 * error. We can always override this later.
700 tmpal = SSL_AD_INTERNAL_ERROR;
702 if (!WPACKET_start_sub_packet_u16(pkt)
704 * If extensions are of zero length then we don't even add the
705 * extensions length bytes to a ClientHello/ServerHello in SSLv3
708 (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0
709 && s->version == SSL3_VERSION
710 && !WPACKET_set_flags(pkt,
711 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
712 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
716 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
717 reason = ssl_get_min_max_version(s, &min_version, &max_version);
719 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason);
724 /* Add custom extensions first */
725 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
726 /* On the server side with initialise during ClientHello parsing */
727 custom_ext_init(&s->cert->custext);
729 if (!custom_ext_add(s, context, pkt, x, chainidx, max_version, &tmpal)) {
730 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
734 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
735 EXT_RETURN (*construct)(SSL *s, WPACKET *pkt, unsigned int context,
736 X509 *x, size_t chainidx, int *al);
739 /* Skip if not relevant for our context */
740 if (!should_add_extension(s, thisexd->context, context, max_version))
743 construct = s->server ? thisexd->construct_stoc
744 : thisexd->construct_ctos;
746 if (construct == NULL)
749 ret = construct(s, pkt, context, x, chainidx, &tmpal);
750 if (ret == EXT_RETURN_FAIL)
752 if (ret == EXT_RETURN_SENT
753 && (context & (SSL_EXT_CLIENT_HELLO
754 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
755 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) != 0)
756 s->ext.extflags[i] |= SSL_EXT_FLAG_SENT;
759 if (!WPACKET_close(pkt)) {
760 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR);
772 * Built in extension finalisation and initialisation functions. All initialise
773 * or finalise the associated extension type for the given |context|. For
774 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
775 * otherwise. These functions return 1 on success or 0 on failure. In the event
776 * of a failure then |*al| is populated with a suitable error code.
779 static int final_renegotiate(SSL *s, unsigned int context, int sent,
784 * Check if we can connect to a server that doesn't support safe
787 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
788 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
790 *al = SSL_AD_HANDSHAKE_FAILURE;
791 SSLerr(SSL_F_FINAL_RENEGOTIATE,
792 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
799 /* Need RI if renegotiating */
801 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
803 *al = SSL_AD_HANDSHAKE_FAILURE;
804 SSLerr(SSL_F_FINAL_RENEGOTIATE,
805 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
813 static int init_server_name(SSL *s, unsigned int context)
816 s->servername_done = 0;
821 static int final_server_name(SSL *s, unsigned int context, int sent,
824 int ret = SSL_TLSEXT_ERR_NOACK;
825 int altmp = SSL_AD_UNRECOGNIZED_NAME;
827 if (s->ctx != NULL && s->ctx->ext.servername_cb != 0)
828 ret = s->ctx->ext.servername_cb(s, &altmp,
829 s->ctx->ext.servername_arg);
830 else if (s->session_ctx != NULL
831 && s->session_ctx->ext.servername_cb != 0)
832 ret = s->session_ctx->ext.servername_cb(s, &altmp,
833 s->session_ctx->ext.servername_arg);
836 case SSL_TLSEXT_ERR_ALERT_FATAL:
840 case SSL_TLSEXT_ERR_ALERT_WARNING:
844 case SSL_TLSEXT_ERR_NOACK:
845 s->servername_done = 0;
853 #ifndef OPENSSL_NO_EC
854 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent,
857 unsigned long alg_k, alg_a;
862 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
863 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
866 * If we are client and using an elliptic curve cryptography cipher
867 * suite, then if server returns an EC point formats lists extension it
868 * must contain uncompressed.
870 if (s->ext.ecpointformats != NULL
871 && s->ext.ecpointformats_len > 0
872 && s->session->ext.ecpointformats != NULL
873 && s->session->ext.ecpointformats_len > 0
874 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
875 /* we are using an ECC cipher */
877 unsigned char *list = s->session->ext.ecpointformats;
879 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
880 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
883 if (i == s->session->ext.ecpointformats_len) {
884 SSLerr(SSL_F_FINAL_EC_PT_FORMATS,
885 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
894 static int init_session_ticket(SSL *s, unsigned int context)
897 s->ext.ticket_expected = 0;
902 #ifndef OPENSSL_NO_OCSP
903 static int init_status_request(SSL *s, unsigned int context)
906 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
909 * Ensure we get sensible values passed to tlsext_status_cb in the event
910 * that we don't receive a status message
912 OPENSSL_free(s->ext.ocsp.resp);
913 s->ext.ocsp.resp = NULL;
914 s->ext.ocsp.resp_len = 0;
921 #ifndef OPENSSL_NO_NEXTPROTONEG
922 static int init_npn(SSL *s, unsigned int context)
930 static int init_alpn(SSL *s, unsigned int context)
932 OPENSSL_free(s->s3->alpn_selected);
933 s->s3->alpn_selected = NULL;
934 s->s3->alpn_selected_len = 0;
936 OPENSSL_free(s->s3->alpn_proposed);
937 s->s3->alpn_proposed = NULL;
938 s->s3->alpn_proposed_len = 0;
943 static int init_sig_algs(SSL *s, unsigned int context)
945 /* Clear any signature algorithms extension received */
946 OPENSSL_free(s->s3->tmp.peer_sigalgs);
947 s->s3->tmp.peer_sigalgs = NULL;
952 #ifndef OPENSSL_NO_SRP
953 static int init_srp(SSL *s, unsigned int context)
955 OPENSSL_free(s->srp_ctx.login);
956 s->srp_ctx.login = NULL;
962 static int init_etm(SSL *s, unsigned int context)
969 static int init_ems(SSL *s, unsigned int context)
972 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
977 static int final_ems(SSL *s, unsigned int context, int sent, int *al)
979 if (!s->server && s->hit) {
981 * Check extended master secret extension is consistent with
984 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
985 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
986 *al = SSL_AD_HANDSHAKE_FAILURE;
987 SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS);
995 static int init_certificate_authorities(SSL *s, unsigned int context)
997 sk_X509_NAME_pop_free(s->s3->tmp.peer_ca_names, X509_NAME_free);
998 s->s3->tmp.peer_ca_names = NULL;
1002 static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
1003 unsigned int context,
1008 const STACK_OF(X509_NAME) *ca_sk = SSL_get0_CA_list(s);
1010 if (ca_sk == NULL || sk_X509_NAME_num(ca_sk) == 0)
1011 return EXT_RETURN_NOT_SENT;
1013 if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_certificate_authorities)
1014 || !WPACKET_start_sub_packet_u16(pkt)
1015 || !construct_ca_names(s, pkt)
1016 || !WPACKET_close(pkt)) {
1017 SSLerr(SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,
1018 ERR_R_INTERNAL_ERROR);
1019 return EXT_RETURN_FAIL;
1022 return EXT_RETURN_SENT;
1025 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
1026 unsigned int context, X509 *x,
1027 size_t chainidx, int *al)
1029 if (!parse_ca_names(s, pkt, al))
1031 if (PACKET_remaining(pkt) != 0) {
1032 *al = SSL_AD_DECODE_ERROR;
1038 #ifndef OPENSSL_NO_SRTP
1039 static int init_srtp(SSL *s, unsigned int context)
1042 s->srtp_profile = NULL;
1048 static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al)
1050 if (!sent && SSL_IS_TLS13(s) && !s->hit) {
1051 *al = TLS13_AD_MISSING_EXTENSION;
1052 SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION);
1059 #ifndef OPENSSL_NO_EC
1060 static int final_key_share(SSL *s, unsigned int context, int sent, int *al)
1062 if (!SSL_IS_TLS13(s))
1065 /* Nothing to do for key_share in an HRR */
1066 if ((context & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0)
1073 * we have no key_share
1075 * (we are not resuming
1076 * OR the kex_mode doesn't allow non key_share resumes)
1083 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
1084 /* Nothing left we can do - just fail */
1085 *al = SSL_AD_MISSING_EXTENSION;
1086 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1093 * we have no key_share
1096 * we didn't already send a HelloRetryRequest
1098 * the client sent a key_share extension
1100 * (we are not resuming
1101 * OR the kex_mode allows key_share resumes)
1103 * a shared group exists
1105 * send a HelloRetryRequest
1107 * we are not resuming
1109 * the kex_mode doesn't allow non key_share resumes
1113 if (s->server && s->s3->peer_tmp == NULL) {
1114 /* No suitable share */
1115 if (s->hello_retry_request == 0 && sent
1117 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1119 const unsigned char *pcurves, *pcurvestmp, *clntcurves;
1120 size_t num_curves, clnt_num_curves, i;
1121 unsigned int group_id = 0;
1123 /* Check if a shared group exists */
1125 /* Get the clients list of supported groups. */
1126 if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) {
1127 *al = SSL_AD_INTERNAL_ERROR;
1128 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1132 /* Get our list of available groups */
1133 if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) {
1134 *al = SSL_AD_INTERNAL_ERROR;
1135 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1139 /* Find the first group we allow that is also in client's list */
1140 for (i = 0, pcurvestmp = pcurves; i < num_curves;
1141 i++, pcurvestmp += 2) {
1142 group_id = bytestogroup(pcurvestmp);
1144 if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1))
1148 if (i < num_curves) {
1149 /* A shared group exists so send a HelloRetryRequest */
1150 s->s3->group_id = group_id;
1151 s->hello_retry_request = 1;
1156 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1157 /* Nothing left we can do - just fail */
1159 *al = SSL_AD_MISSING_EXTENSION;
1161 *al = SSL_AD_HANDSHAKE_FAILURE;
1162 SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1167 /* We have a key_share so don't send any more HelloRetryRequest messages */
1169 s->hello_retry_request = 0;
1172 * For a client side resumption with no key_share we need to generate
1173 * the handshake secret (otherwise this is done during key_share
1176 if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) {
1177 *al = SSL_AD_INTERNAL_ERROR;
1178 SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR);
1186 static int init_psk_kex_modes(SSL *s, unsigned int context)
1188 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1192 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1193 size_t binderoffset, const unsigned char *binderin,
1194 unsigned char *binderout, SSL_SESSION *sess, int sign,
1197 EVP_PKEY *mackey = NULL;
1198 EVP_MD_CTX *mctx = NULL;
1199 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1200 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1201 unsigned char tmppsk[EVP_MAX_MD_SIZE];
1202 unsigned char *early_secret, *psk;
1203 const char resumption_label[] = "res binder";
1204 const char external_label[] = "ext binder";
1205 const char nonce_label[] = "resumption";
1207 size_t bindersize, labelsize, hashsize = EVP_MD_size(md);
1209 int usepskfored = 0;
1212 && s->early_data_state == SSL_EARLY_DATA_CONNECTING
1213 && s->session->ext.max_early_data == 0
1214 && sess->ext.max_early_data > 0)
1218 label = external_label;
1219 labelsize = sizeof(external_label) - 1;
1221 label = resumption_label;
1222 labelsize = sizeof(resumption_label) - 1;
1225 if (sess->master_key_length != hashsize) {
1226 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_PSK);
1231 psk = sess->master_key;
1234 if (!tls13_hkdf_expand(s, md, sess->master_key,
1235 (const unsigned char *)nonce_label,
1236 sizeof(nonce_label) - 1, sess->ext.tick_nonce,
1237 sess->ext.tick_nonce_len, psk, hashsize)) {
1238 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1244 * Generate the early_secret. On the server side we've selected a PSK to
1245 * resume with (internal or external) so we always do this. On the client
1246 * side we do this for a non-external (i.e. resumption) PSK or external PSK
1247 * that will be used for early_data so that it is in place for sending early
1248 * data. For client side external PSK not being used for early_data we
1249 * generate it but store it away for later use.
1251 if (s->server || !external || usepskfored)
1252 early_secret = (unsigned char *)s->early_secret;
1254 early_secret = (unsigned char *)sess->early_secret;
1255 if (!tls13_generate_secret(s, md, NULL, psk, hashsize, early_secret)) {
1256 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1261 * Create the handshake hash for the binder key...the messages so far are
1264 mctx = EVP_MD_CTX_new();
1266 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1267 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1268 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1272 /* Generate the binder key */
1273 if (!tls13_hkdf_expand(s, md, early_secret, (unsigned char *)label,
1274 labelsize, hash, hashsize, binderkey, hashsize)) {
1275 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1279 /* Generate the finished key */
1280 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1281 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1285 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1286 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1291 * Get a hash of the ClientHello up to the start of the binders. If we are
1292 * following a HelloRetryRequest then this includes the hash of the first
1293 * ClientHello and the HelloRetryRequest itself.
1295 if (s->hello_retry_request) {
1299 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
1300 if (hdatalen <= 0) {
1301 SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_HANDSHAKE_LENGTH);
1306 * For servers the handshake buffer data will include the second
1307 * ClientHello - which we don't want - so we need to take that bit off.
1310 PACKET hashprefix, msg;
1312 /* Find how many bytes are left after the first two messages */
1313 if (!PACKET_buf_init(&hashprefix, hdata, hdatalen)
1314 || !PACKET_forward(&hashprefix, 1)
1315 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)
1316 || !PACKET_forward(&hashprefix, 1)
1317 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)) {
1318 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1321 hdatalen -= PACKET_remaining(&hashprefix);
1324 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1325 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1330 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1331 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1332 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1336 mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize);
1337 if (mackey == NULL) {
1338 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1343 binderout = tmpbinder;
1345 bindersize = hashsize;
1346 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1347 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1348 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1349 || bindersize != hashsize) {
1350 SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
1357 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1358 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1362 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1363 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1364 EVP_PKEY_free(mackey);
1365 EVP_MD_CTX_free(mctx);
1370 static int final_early_data(SSL *s, unsigned int context, int sent, int *al)
1372 if (!s->server || !sent)
1375 if (s->max_early_data == 0
1377 || s->session->ext.tick_identity != 0
1378 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
1379 || !s->ext.early_data_ok
1380 || s->hello_retry_request
1381 || s->s3->alpn_selected_len != s->session->ext.alpn_selected_len
1382 || (s->s3->alpn_selected_len > 0
1383 && memcmp(s->s3->alpn_selected, s->session->ext.alpn_selected,
1384 s->s3->alpn_selected_len) != 0)) {
1385 s->ext.early_data = SSL_EARLY_DATA_REJECTED;
1387 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;
1389 if (!tls13_change_cipher_state(s,
1390 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) {
1391 *al = SSL_AD_INTERNAL_ERROR;