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
10 #include "../ssl_locl.h"
11 #include "statem_locl.h"
13 static int final_renegotiate(SSL
*s
, unsigned int context
, int sent
,
15 static int init_server_name(SSL
*s
, unsigned int context
);
16 static int final_server_name(SSL
*s
, unsigned int context
, int sent
,
19 static int final_ec_pt_formats(SSL
*s
, unsigned int context
, int sent
,
22 static int init_session_ticket(SSL
*s
, unsigned int context
);
23 #ifndef OPENSSL_NO_OCSP
24 static int init_status_request(SSL
*s
, unsigned int context
);
26 #ifndef OPENSSL_NO_NEXTPROTONEG
27 static int init_npn(SSL
*s
, unsigned int context
);
29 static int init_alpn(SSL
*s
, unsigned int context
);
30 static int final_alpn(SSL
*s
, unsigned int context
, int sent
, int *al
);
31 static int init_sig_algs(SSL
*s
, unsigned int context
);
32 #ifndef OPENSSL_NO_SRP
33 static int init_srp(SSL
*s
, unsigned int context
);
35 static int init_etm(SSL
*s
, unsigned int context
);
36 static int init_ems(SSL
*s
, unsigned int context
);
37 static int final_ems(SSL
*s
, unsigned int context
, int sent
, int *al
);
38 static int init_psk_kex_modes(SSL
*s
, unsigned int context
);
40 static int final_key_share(SSL
*s
, unsigned int context
, int sent
, int *al
);
42 #ifndef OPENSSL_NO_SRTP
43 static int init_srtp(SSL
*s
, unsigned int context
);
45 static int final_sig_algs(SSL
*s
, unsigned int context
, int sent
, int *al
);
47 /* Structure to define a built-in extension */
48 typedef struct extensions_definition_st
{
49 /* The defined type for the extension */
52 * The context that this extension applies to, e.g. what messages and
57 * Initialise extension before parsing. Always called for relevant contexts
58 * even if extension not present
60 int (*init
)(SSL
*s
, unsigned int context
);
61 /* Parse extension sent from client to server */
62 int (*parse_ctos
)(SSL
*s
, PACKET
*pkt
, unsigned int context
, X509
*x
,
63 size_t chainidx
, int *al
);
64 /* Parse extension send from server to client */
65 int (*parse_stoc
)(SSL
*s
, PACKET
*pkt
, unsigned int context
, X509
*x
,
66 size_t chainidx
, int *al
);
67 /* Construct extension sent from server to client */
68 int (*construct_stoc
)(SSL
*s
, WPACKET
*pkt
, unsigned int context
, X509
*x
,
69 size_t chainidx
, int *al
);
70 /* Construct extension sent from client to server */
71 int (*construct_ctos
)(SSL
*s
, WPACKET
*pkt
, unsigned int context
, X509
*x
,
72 size_t chainidx
, int *al
);
74 * Finalise extension after parsing. Always called where an extensions was
75 * initialised even if the extension was not present. |sent| is set to 1 if
76 * the extension was seen, or 0 otherwise.
78 int (*final
)(SSL
*s
, unsigned int context
, int sent
, int *al
);
79 } EXTENSION_DEFINITION
;
82 * Definitions of all built-in extensions. NOTE: Changes in the number or order
83 * of these extensions should be mirrored with equivalent changes to the
84 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
85 * Each extension has an initialiser, a client and
86 * server side parser and a finaliser. The initialiser is called (if the
87 * extension is relevant to the given context) even if we did not see the
88 * extension in the message that we received. The parser functions are only
89 * called if we see the extension in the message. The finalisers are always
90 * called if the initialiser was called.
91 * There are also server and client side constructor functions which are always
92 * called during message construction if the extension is relevant for the
94 * The initialisation, parsing, finalisation and construction functions are
95 * always called in the order defined in this list. Some extensions may depend
96 * on others having been processed first, so the order of this list is
98 * The extension context is defined by a series of flags which specify which
99 * messages the extension is relevant to. These flags also specify whether the
100 * extension is relevant to a particular protocol or protocol version.
102 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
104 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
105 static const EXTENSION_DEFINITION ext_defs
[] = {
107 TLSEXT_TYPE_renegotiate
,
108 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_SSL3_ALLOWED
109 | EXT_TLS1_2_AND_BELOW_ONLY
,
110 NULL
, tls_parse_ctos_renegotiate
, tls_parse_stoc_renegotiate
,
111 tls_construct_stoc_renegotiate
, tls_construct_ctos_renegotiate
,
115 TLSEXT_TYPE_server_name
,
116 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
117 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
119 tls_parse_ctos_server_name
, tls_parse_stoc_server_name
,
120 tls_construct_stoc_server_name
, tls_construct_ctos_server_name
,
123 #ifndef OPENSSL_NO_SRP
126 EXT_CLIENT_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
127 init_srp
, tls_parse_ctos_srp
, NULL
, NULL
, tls_construct_ctos_srp
, NULL
133 TLSEXT_TYPE_early_data_info
,
134 EXT_TLS1_3_NEW_SESSION_TICKET
,
135 NULL
, NULL
, tls_parse_stoc_early_data_info
,
136 tls_construct_stoc_early_data_info
, NULL
, NULL
139 TLSEXT_TYPE_early_data
,
140 EXT_CLIENT_HELLO
| EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
141 NULL
, tls_parse_ctos_early_data
, NULL
, NULL
,
142 tls_construct_ctos_early_data
, NULL
144 #ifndef OPENSSL_NO_EC
146 TLSEXT_TYPE_ec_point_formats
,
147 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
148 NULL
, tls_parse_ctos_ec_pt_formats
, tls_parse_stoc_ec_pt_formats
,
149 tls_construct_stoc_ec_pt_formats
, tls_construct_ctos_ec_pt_formats
,
153 TLSEXT_TYPE_supported_groups
,
154 EXT_CLIENT_HELLO
| EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
155 NULL
, tls_parse_ctos_supported_groups
, NULL
,
156 NULL
/* TODO(TLS1.3): Need to add this */,
157 tls_construct_ctos_supported_groups
, NULL
164 TLSEXT_TYPE_session_ticket
,
165 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
166 init_session_ticket
, tls_parse_ctos_session_ticket
,
167 tls_parse_stoc_session_ticket
, tls_construct_stoc_session_ticket
,
168 tls_construct_ctos_session_ticket
, NULL
171 TLSEXT_TYPE_signature_algorithms
,
173 init_sig_algs
, tls_parse_ctos_sig_algs
, NULL
, NULL
,
174 tls_construct_ctos_sig_algs
, final_sig_algs
176 #ifndef OPENSSL_NO_OCSP
178 TLSEXT_TYPE_status_request
,
179 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
180 | 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 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
192 init_npn
, tls_parse_ctos_npn
, tls_parse_stoc_npn
,
193 tls_construct_stoc_next_proto_neg
, tls_construct_ctos_npn
, NULL
200 * Must appear in this list after server_name so that finalisation
201 * happens after server_name callbacks
203 TLSEXT_TYPE_application_layer_protocol_negotiation
,
204 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
205 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
206 init_alpn
, tls_parse_ctos_alpn
, tls_parse_stoc_alpn
,
207 tls_construct_stoc_alpn
, tls_construct_ctos_alpn
, final_alpn
209 #ifndef OPENSSL_NO_SRTP
211 TLSEXT_TYPE_use_srtp
,
212 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
213 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
| EXT_DTLS_ONLY
,
214 init_srtp
, tls_parse_ctos_use_srtp
, tls_parse_stoc_use_srtp
,
215 tls_construct_stoc_use_srtp
, tls_construct_ctos_use_srtp
, NULL
221 TLSEXT_TYPE_encrypt_then_mac
,
222 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
| EXT_SSL3_ALLOWED
,
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 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
230 | 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 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| 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_supported_versions
,
250 EXT_CLIENT_HELLO
| EXT_TLS_IMPLEMENTATION_ONLY
| EXT_TLS1_3_ONLY
,
252 /* Processed inline as part of version selection */
253 NULL
, NULL
, NULL
, tls_construct_ctos_supported_versions
, NULL
256 TLSEXT_TYPE_psk_kex_modes
,
257 EXT_CLIENT_HELLO
| EXT_TLS_IMPLEMENTATION_ONLY
| EXT_TLS1_3_ONLY
,
258 init_psk_kex_modes
, tls_parse_ctos_psk_kex_modes
, NULL
, NULL
,
259 tls_construct_ctos_psk_kex_modes
, NULL
261 #ifndef OPENSSL_NO_EC
264 * Must be in this list after supported_groups. We need that to have
265 * been parsed before we do this one.
267 TLSEXT_TYPE_key_share
,
268 EXT_CLIENT_HELLO
| EXT_TLS1_3_SERVER_HELLO
269 | EXT_TLS1_3_HELLO_RETRY_REQUEST
| EXT_TLS_IMPLEMENTATION_ONLY
271 NULL
, tls_parse_ctos_key_share
, tls_parse_stoc_key_share
,
272 tls_construct_stoc_key_share
, tls_construct_ctos_key_share
,
278 * Special unsolicited ServerHello extension only used when
279 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
281 TLSEXT_TYPE_cryptopro_bug
,
282 EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
283 NULL
, NULL
, NULL
, tls_construct_stoc_cryptopro_bug
, NULL
, NULL
286 /* Must be immediately before pre_shared_key */
287 /* TODO(TLS1.3): Fix me */
291 /* We send this, but don't read it */
292 NULL
, NULL
, NULL
, tls_construct_ctos_padding
, NULL
295 /* Required by the TLSv1.3 spec to always be the last extension */
297 EXT_CLIENT_HELLO
| EXT_TLS1_3_SERVER_HELLO
| EXT_TLS_IMPLEMENTATION_ONLY
299 NULL
, tls_parse_ctos_psk
, tls_parse_stoc_psk
, tls_construct_stoc_psk
,
300 tls_construct_ctos_psk
, NULL
305 * Verify whether we are allowed to use the extension |type| in the current
306 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
307 * indicate the extension is not allowed. If returning 1 then |*found| is set to
308 * 1 if we found a definition for the extension, and |*idx| is set to its index
310 static int verify_extension(SSL
*s
, unsigned int context
, unsigned int type
,
311 custom_ext_methods
*meths
, RAW_EXTENSION
*rawexlist
,
312 RAW_EXTENSION
**found
)
315 size_t builtin_num
= OSSL_NELEM(ext_defs
);
316 const EXTENSION_DEFINITION
*thisext
;
318 for (i
= 0, thisext
= ext_defs
; i
< builtin_num
; i
++, thisext
++) {
319 if (type
== thisext
->type
) {
320 /* Check we're allowed to use this extension in this context */
321 if ((context
& thisext
->context
) == 0)
324 if (SSL_IS_DTLS(s
)) {
325 if ((thisext
->context
& EXT_TLS_ONLY
) != 0)
327 } else if ((thisext
->context
& EXT_DTLS_ONLY
) != 0) {
331 *found
= &rawexlist
[i
];
336 if ((context
& (EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
)) == 0) {
338 * Custom extensions only apply to <=TLS1.2. This extension is unknown
339 * in this context - we allow it
345 /* Check the custom extensions */
347 for (i
= builtin_num
; i
< builtin_num
+ meths
->meths_count
; i
++) {
348 if (meths
->meths
[i
- builtin_num
].ext_type
== type
) {
349 *found
= &rawexlist
[i
];
355 /* Unknown extension. We allow it */
361 * Check whether the context defined for an extension |extctx| means whether
362 * the extension is relevant for the current context |thisctx| or not. Returns
363 * 1 if the extension is relevant for this context, and 0 otherwise
365 static int extension_is_relevant(SSL
*s
, unsigned int extctx
,
366 unsigned int thisctx
)
369 && (extctx
& EXT_TLS_IMPLEMENTATION_ONLY
) != 0)
370 || (s
->version
== SSL3_VERSION
371 && (extctx
& EXT_SSL3_ALLOWED
) == 0)
373 && (extctx
& EXT_TLS1_2_AND_BELOW_ONLY
) != 0)
374 || (!SSL_IS_TLS13(s
) && (extctx
& EXT_TLS1_3_ONLY
) != 0))
381 * Gather a list of all the extensions from the data in |packet]. |context|
382 * tells us which message this extension is for. The raw extension data is
383 * stored in |*res| on success. In the event of an error the alert type to use
384 * is stored in |*al|. We don't actually process the content of the extensions
385 * yet, except to check their types. This function also runs the initialiser
386 * functions for all known extensions (whether we have collected them or not).
387 * If successful the caller is responsible for freeing the contents of |*res|.
389 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
390 * more than one extension of the same type in a ClientHello or ServerHello.
391 * This function returns 1 if all extensions are unique and we have parsed their
392 * types, and 0 if the extensions contain duplicates, could not be successfully
393 * found, or an internal error occurred. We only check duplicates for
394 * extensions that we know about. We ignore others.
396 int tls_collect_extensions(SSL
*s
, PACKET
*packet
, unsigned int context
,
397 RAW_EXTENSION
**res
, int *al
, size_t *len
)
399 PACKET extensions
= *packet
;
402 custom_ext_methods
*exts
= NULL
;
403 RAW_EXTENSION
*raw_extensions
= NULL
;
404 const EXTENSION_DEFINITION
*thisexd
;
409 * Initialise server side custom extensions. Client side is done during
410 * construction of extensions for the ClientHello.
412 if ((context
& EXT_CLIENT_HELLO
) != 0) {
413 exts
= &s
->cert
->srv_ext
;
414 custom_ext_init(&s
->cert
->srv_ext
);
415 } else if ((context
& EXT_TLS1_2_SERVER_HELLO
) != 0) {
416 exts
= &s
->cert
->cli_ext
;
419 num_exts
= OSSL_NELEM(ext_defs
) + (exts
!= NULL
? exts
->meths_count
: 0);
420 raw_extensions
= OPENSSL_zalloc(num_exts
* sizeof(*raw_extensions
));
421 if (raw_extensions
== NULL
) {
422 *al
= SSL_AD_INTERNAL_ERROR
;
423 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS
, ERR_R_MALLOC_FAILURE
);
427 while (PACKET_remaining(&extensions
) > 0) {
430 RAW_EXTENSION
*thisex
;
432 if (!PACKET_get_net_2(&extensions
, &type
) ||
433 !PACKET_get_length_prefixed_2(&extensions
, &extension
)) {
434 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS
, SSL_R_BAD_EXTENSION
);
435 *al
= SSL_AD_DECODE_ERROR
;
439 * Verify this extension is allowed. We only check duplicates for
440 * extensions that we recognise.
442 if (!verify_extension(s
, context
, type
, exts
, raw_extensions
, &thisex
)
443 || (thisex
!= NULL
&& thisex
->present
== 1)) {
444 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS
, SSL_R_BAD_EXTENSION
);
445 *al
= SSL_AD_ILLEGAL_PARAMETER
;
448 if (thisex
!= NULL
) {
449 thisex
->data
= extension
;
456 * Initialise all known extensions relevant to this context, whether we have
459 for (thisexd
= ext_defs
, i
= 0; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
460 if(thisexd
->init
!= NULL
&& (thisexd
->context
& context
) != 0
461 && extension_is_relevant(s
, thisexd
->context
, context
)
462 && !thisexd
->init(s
, context
)) {
463 *al
= SSL_AD_INTERNAL_ERROR
;
468 *res
= raw_extensions
;
474 OPENSSL_free(raw_extensions
);
479 * Runs the parser for a given extension with index |idx|. |exts| contains the
480 * list of all parsed extensions previously collected by
481 * tls_collect_extensions(). The parser is only run if it is applicable for the
482 * given |context| and the parser has not already been run. If this is for a
483 * Certificate message, then we also provide the parser with the relevant
484 * Certificate |x| and its position in the |chainidx| with 0 being the first
485 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
486 * |*al| is populated with a suitable alert code. If an extension is not present
487 * this counted as success.
489 int tls_parse_extension(SSL
*s
, TLSEXT_INDEX idx
, int context
,
490 RAW_EXTENSION
*exts
, X509
*x
, size_t chainidx
, int *al
)
492 RAW_EXTENSION
*currext
= &exts
[idx
];
493 int (*parser
)(SSL
*s
, PACKET
*pkt
, unsigned int context
, X509
*x
,
494 size_t chainidx
, int *al
) = NULL
;
496 /* Skip if the extension is not present */
497 if (!currext
->present
)
501 s
->ext
.debug_cb(s
, !s
->server
, currext
->type
,
502 PACKET_data(&currext
->data
),
503 PACKET_remaining(&currext
->data
),
506 /* Skip if we've already parsed this extension */
512 if (idx
< OSSL_NELEM(ext_defs
)) {
513 /* We are handling a built-in extension */
514 const EXTENSION_DEFINITION
*extdef
= &ext_defs
[idx
];
516 /* Check if extension is defined for our protocol. If not, skip */
517 if (!extension_is_relevant(s
, extdef
->context
, context
))
520 parser
= s
->server
? extdef
->parse_ctos
: extdef
->parse_stoc
;
523 return parser(s
, &currext
->data
, context
, x
, chainidx
, al
);
526 * If the parser is NULL we fall through to the custom extension
532 * This is a custom extension. We only allow this if it is a non
533 * resumed session on the server side.
535 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
536 * We're going to need a new mechanism for TLS1.3 to specify which
537 * messages to add the custom extensions to.
539 if ((!s
->hit
|| !s
->server
)
541 & (EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
)) != 0
542 && custom_ext_parse(s
, s
->server
, currext
->type
,
543 PACKET_data(&currext
->data
),
544 PACKET_remaining(&currext
->data
),
552 * Parse all remaining extensions that have not yet been parsed. Also calls the
553 * finalisation for all extensions at the end, whether we collected them or not.
554 * Returns 1 for success or 0 for failure. If we are working on a Certificate
555 * message then we also pass the Certificate |x| and its position in the
556 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
557 * populated with a suitable alert code.
559 int tls_parse_all_extensions(SSL
*s
, int context
, RAW_EXTENSION
*exts
, X509
*x
,
560 size_t chainidx
, int *al
)
562 size_t i
, numexts
= OSSL_NELEM(ext_defs
);
563 const EXTENSION_DEFINITION
*thisexd
;
565 /* Calculate the number of extensions in the extensions list */
566 if ((context
& EXT_CLIENT_HELLO
) != 0) {
567 numexts
+= s
->cert
->srv_ext
.meths_count
;
568 } else if ((context
& EXT_TLS1_2_SERVER_HELLO
) != 0) {
569 numexts
+= s
->cert
->cli_ext
.meths_count
;
572 /* Parse each extension in turn */
573 for (i
= 0; i
< numexts
; i
++) {
574 if (!tls_parse_extension(s
, i
, context
, exts
, x
, chainidx
, al
))
579 * Finalise all known extensions relevant to this context, whether we have
582 for (i
= 0, thisexd
= ext_defs
; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
583 if(thisexd
->final
!= NULL
584 && (thisexd
->context
& context
) != 0
585 && !thisexd
->final(s
, context
, exts
[i
].present
, al
))
593 * Construct all the extensions relevant to the current |context| and write
594 * them to |pkt|. If this is an extension for a Certificate in a Certificate
595 * message, then |x| will be set to the Certificate we are handling, and
596 * |chainidx| will indicate the position in the chainidx we are processing (with
597 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
598 * failure occurs then |al| is populated with a suitable alert code. On a
599 * failure construction stops at the first extension to fail to construct.
601 int tls_construct_extensions(SSL
*s
, WPACKET
*pkt
, unsigned int context
,
602 X509
*x
, size_t chainidx
, int *al
)
605 int addcustom
= 0, min_version
, max_version
= 0, reason
, tmpal
;
606 const EXTENSION_DEFINITION
*thisexd
;
609 * Normally if something goes wrong during construction it's an internal
610 * error. We can always override this later.
612 tmpal
= SSL_AD_INTERNAL_ERROR
;
614 if (!WPACKET_start_sub_packet_u16(pkt
)
616 * If extensions are of zero length then we don't even add the
617 * extensions length bytes to a ClientHello/ServerHello in SSLv3
619 || ((context
& (EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
)) != 0
620 && s
->version
== SSL3_VERSION
621 && !WPACKET_set_flags(pkt
,
622 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH
))) {
623 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, ERR_R_INTERNAL_ERROR
);
627 if ((context
& EXT_CLIENT_HELLO
) != 0) {
628 reason
= ssl_get_client_min_max_version(s
, &min_version
, &max_version
);
630 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, reason
);
635 /* Add custom extensions first */
636 if ((context
& EXT_CLIENT_HELLO
) != 0) {
637 custom_ext_init(&s
->cert
->cli_ext
);
639 } else if ((context
& EXT_TLS1_2_SERVER_HELLO
) != 0) {
641 * We already initialised the custom extensions during ClientHello
644 * TODO(TLS1.3): We're going to need a new custom extension mechanism
645 * for TLS1.3, so that custom extensions can specify which of the
646 * multiple message they wish to add themselves to.
651 if (addcustom
&& !custom_ext_add(s
, s
->server
, pkt
, &tmpal
)) {
652 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, ERR_R_INTERNAL_ERROR
);
656 for (i
= 0, thisexd
= ext_defs
; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
657 int (*construct
)(SSL
*s
, WPACKET
*pkt
, unsigned int context
, X509
*x
,
658 size_t chainidx
, int *al
);
660 /* Skip if not relevant for our context */
661 if ((thisexd
->context
& context
) == 0)
664 construct
= s
->server
? thisexd
->construct_stoc
665 : thisexd
->construct_ctos
;
667 /* Check if this extension is defined for our protocol. If not, skip */
669 && (thisexd
->context
& EXT_TLS_IMPLEMENTATION_ONLY
)
671 || (s
->version
== SSL3_VERSION
672 && (thisexd
->context
& EXT_SSL3_ALLOWED
) == 0)
674 && (thisexd
->context
& EXT_TLS1_2_AND_BELOW_ONLY
)
677 && (thisexd
->context
& EXT_TLS1_3_ONLY
) != 0
678 && (context
& EXT_CLIENT_HELLO
) == 0)
679 || ((thisexd
->context
& EXT_TLS1_3_ONLY
) != 0
680 && (context
& EXT_CLIENT_HELLO
) != 0
681 && (SSL_IS_DTLS(s
) || max_version
< TLS1_3_VERSION
))
682 || construct
== NULL
)
685 if (!construct(s
, pkt
, context
, x
, chainidx
, &tmpal
))
689 if (!WPACKET_close(pkt
)) {
690 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, ERR_R_INTERNAL_ERROR
);
702 * Built in extension finalisation and initialisation functions. All initialise
703 * or finalise the associated extension type for the given |context|. For
704 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
705 * otherwise. These functions return 1 on success or 0 on failure. In the event
706 * of a failure then |*al| is populated with a suitable error code.
709 static int final_renegotiate(SSL
*s
, unsigned int context
, int sent
,
714 * Check if we can connect to a server that doesn't support safe
717 if (!(s
->options
& SSL_OP_LEGACY_SERVER_CONNECT
)
718 && !(s
->options
& SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
)
720 *al
= SSL_AD_HANDSHAKE_FAILURE
;
721 SSLerr(SSL_F_FINAL_RENEGOTIATE
,
722 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED
);
729 /* Need RI if renegotiating */
731 && !(s
->options
& SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
)
733 *al
= SSL_AD_HANDSHAKE_FAILURE
;
734 SSLerr(SSL_F_FINAL_RENEGOTIATE
,
735 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED
);
743 static int init_server_name(SSL
*s
, unsigned int context
)
746 s
->servername_done
= 0;
751 static int final_server_name(SSL
*s
, unsigned int context
, int sent
,
754 int ret
= SSL_TLSEXT_ERR_NOACK
;
755 int altmp
= SSL_AD_UNRECOGNIZED_NAME
;
757 if (s
->ctx
!= NULL
&& s
->ctx
->ext
.servername_cb
!= 0)
758 ret
= s
->ctx
->ext
.servername_cb(s
, &altmp
,
759 s
->ctx
->ext
.servername_arg
);
760 else if (s
->session_ctx
!= NULL
761 && s
->session_ctx
->ext
.servername_cb
!= 0)
762 ret
= s
->session_ctx
->ext
.servername_cb(s
, &altmp
,
763 s
->session_ctx
->ext
.servername_arg
);
766 case SSL_TLSEXT_ERR_ALERT_FATAL
:
770 case SSL_TLSEXT_ERR_ALERT_WARNING
:
774 case SSL_TLSEXT_ERR_NOACK
:
775 s
->servername_done
= 0;
783 #ifndef OPENSSL_NO_EC
784 static int final_ec_pt_formats(SSL
*s
, unsigned int context
, int sent
,
787 unsigned long alg_k
, alg_a
;
792 alg_k
= s
->s3
->tmp
.new_cipher
->algorithm_mkey
;
793 alg_a
= s
->s3
->tmp
.new_cipher
->algorithm_auth
;
796 * If we are client and using an elliptic curve cryptography cipher
797 * suite, then if server returns an EC point formats lists extension it
798 * must contain uncompressed.
800 if (s
->ext
.ecpointformats
!= NULL
801 && s
->ext
.ecpointformats_len
> 0
802 && s
->session
->ext
.ecpointformats
!= NULL
803 && s
->session
->ext
.ecpointformats_len
> 0
804 && ((alg_k
& SSL_kECDHE
) || (alg_a
& SSL_aECDSA
))) {
805 /* we are using an ECC cipher */
807 unsigned char *list
= s
->session
->ext
.ecpointformats
;
809 for (i
= 0; i
< s
->session
->ext
.ecpointformats_len
; i
++) {
810 if (*list
++ == TLSEXT_ECPOINTFORMAT_uncompressed
)
813 if (i
== s
->session
->ext
.ecpointformats_len
) {
814 SSLerr(SSL_F_FINAL_EC_PT_FORMATS
,
815 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST
);
824 static int init_session_ticket(SSL
*s
, unsigned int context
)
827 s
->ext
.ticket_expected
= 0;
832 #ifndef OPENSSL_NO_OCSP
833 static int init_status_request(SSL
*s
, unsigned int context
)
836 s
->ext
.status_type
= TLSEXT_STATUSTYPE_nothing
;
839 * Ensure we get sensible values passed to tlsext_status_cb in the event
840 * that we don't receive a status message
842 OPENSSL_free(s
->ext
.ocsp
.resp
);
843 s
->ext
.ocsp
.resp
= NULL
;
844 s
->ext
.ocsp
.resp_len
= 0;
851 #ifndef OPENSSL_NO_NEXTPROTONEG
852 static int init_npn(SSL
*s
, unsigned int context
)
860 static int init_alpn(SSL
*s
, unsigned int context
)
862 OPENSSL_free(s
->s3
->alpn_selected
);
863 s
->s3
->alpn_selected
= NULL
;
865 s
->s3
->alpn_selected_len
= 0;
866 OPENSSL_free(s
->s3
->alpn_proposed
);
867 s
->s3
->alpn_proposed
= NULL
;
868 s
->s3
->alpn_proposed_len
= 0;
873 static int final_alpn(SSL
*s
, unsigned int context
, int sent
, int *al
)
875 const unsigned char *selected
= NULL
;
876 unsigned char selected_len
= 0;
881 if (s
->ctx
->ext
.alpn_select_cb
!= NULL
&& s
->s3
->alpn_proposed
!= NULL
) {
882 int r
= s
->ctx
->ext
.alpn_select_cb(s
, &selected
, &selected_len
,
883 s
->s3
->alpn_proposed
,
884 (unsigned int)s
->s3
->alpn_proposed_len
,
885 s
->ctx
->ext
.alpn_select_cb_arg
);
887 if (r
== SSL_TLSEXT_ERR_OK
) {
888 OPENSSL_free(s
->s3
->alpn_selected
);
889 s
->s3
->alpn_selected
= OPENSSL_memdup(selected
, selected_len
);
890 if (s
->s3
->alpn_selected
== NULL
) {
891 *al
= SSL_AD_INTERNAL_ERROR
;
894 s
->s3
->alpn_selected_len
= selected_len
;
895 #ifndef OPENSSL_NO_NEXTPROTONEG
896 /* ALPN takes precedence over NPN. */
900 *al
= SSL_AD_NO_APPLICATION_PROTOCOL
;
908 static int init_sig_algs(SSL
*s
, unsigned int context
)
910 /* Clear any signature algorithms extension received */
911 OPENSSL_free(s
->s3
->tmp
.peer_sigalgs
);
912 s
->s3
->tmp
.peer_sigalgs
= NULL
;
917 #ifndef OPENSSL_NO_SRP
918 static int init_srp(SSL
*s
, unsigned int context
)
920 OPENSSL_free(s
->srp_ctx
.login
);
921 s
->srp_ctx
.login
= NULL
;
927 static int init_etm(SSL
*s
, unsigned int context
)
934 static int init_ems(SSL
*s
, unsigned int context
)
937 s
->s3
->flags
&= ~TLS1_FLAGS_RECEIVED_EXTMS
;
942 static int final_ems(SSL
*s
, unsigned int context
, int sent
, int *al
)
944 if (!s
->server
&& s
->hit
) {
946 * Check extended master secret extension is consistent with
949 if (!(s
->s3
->flags
& TLS1_FLAGS_RECEIVED_EXTMS
) !=
950 !(s
->session
->flags
& SSL_SESS_FLAG_EXTMS
)) {
951 *al
= SSL_AD_HANDSHAKE_FAILURE
;
952 SSLerr(SSL_F_FINAL_EMS
, SSL_R_INCONSISTENT_EXTMS
);
960 #ifndef OPENSSL_NO_SRTP
961 static int init_srtp(SSL
*s
, unsigned int context
)
964 s
->srtp_profile
= NULL
;
970 static int final_sig_algs(SSL
*s
, unsigned int context
, int sent
, int *al
)
972 if (!sent
&& SSL_IS_TLS13(s
)) {
973 *al
= TLS13_AD_MISSING_EXTENSION
;
974 SSLerr(SSL_F_FINAL_SIG_ALGS
, SSL_R_MISSING_SIGALGS_EXTENSION
);
981 #ifndef OPENSSL_NO_EC
982 static int final_key_share(SSL
*s
, unsigned int context
, int sent
, int *al
)
984 if (!SSL_IS_TLS13(s
))
991 * we have no key_share
993 * (we are not resuming
994 * OR the kex_mode doesn't allow non key_share resumes)
1001 || (s
->ext
.psk_kex_mode
& TLSEXT_KEX_MODE_FLAG_KE
) == 0)) {
1002 /* Nothing left we can do - just fail */
1003 *al
= SSL_AD_HANDSHAKE_FAILURE
;
1004 SSLerr(SSL_F_FINAL_KEY_SHARE
, SSL_R_NO_SUITABLE_KEY_SHARE
);
1011 * we have no key_share
1014 * we didn't already send a HelloRetryRequest
1016 * the client sent a key_share extension
1018 * (we are not resuming
1019 * OR the kex_mode allows key_share resumes)
1021 * a shared group exists
1023 * send a HelloRetryRequest
1025 * we are not resuming
1027 * the kex_mode doesn't allow non key_share resumes
1031 if (s
->server
&& s
->s3
->peer_tmp
== NULL
) {
1032 /* No suitable share */
1033 if (s
->hello_retry_request
== 0 && sent
1035 || (s
->ext
.psk_kex_mode
& TLSEXT_KEX_MODE_FLAG_KE_DHE
)
1037 const unsigned char *pcurves
, *pcurvestmp
, *clntcurves
;
1038 size_t num_curves
, clnt_num_curves
, i
;
1039 unsigned int group_id
= 0;
1041 /* Check if a shared group exists */
1043 /* Get the clients list of supported groups. */
1044 if (!tls1_get_curvelist(s
, 1, &clntcurves
, &clnt_num_curves
)) {
1045 *al
= SSL_AD_INTERNAL_ERROR
;
1046 SSLerr(SSL_F_FINAL_KEY_SHARE
, ERR_R_INTERNAL_ERROR
);
1050 /* Get our list of available groups */
1051 if (!tls1_get_curvelist(s
, 0, &pcurves
, &num_curves
)) {
1052 *al
= SSL_AD_INTERNAL_ERROR
;
1053 SSLerr(SSL_F_FINAL_KEY_SHARE
, ERR_R_INTERNAL_ERROR
);
1057 /* Find the first group we allow that is also in client's list */
1058 for (i
= 0, pcurvestmp
= pcurves
; i
< num_curves
;
1059 i
++, pcurvestmp
+= 2) {
1060 group_id
= bytestogroup(pcurvestmp
);
1062 if (check_in_list(s
, group_id
, clntcurves
, clnt_num_curves
, 1))
1066 if (i
< num_curves
) {
1067 /* A shared group exists so send a HelloRetryRequest */
1068 s
->s3
->group_id
= group_id
;
1069 s
->hello_retry_request
= 1;
1074 || (s
->ext
.psk_kex_mode
& TLSEXT_KEX_MODE_FLAG_KE
) == 0) {
1075 /* Nothing left we can do - just fail */
1076 *al
= SSL_AD_HANDSHAKE_FAILURE
;
1077 SSLerr(SSL_F_FINAL_KEY_SHARE
, SSL_R_NO_SUITABLE_KEY_SHARE
);
1082 /* We have a key_share so don't send any more HelloRetryRequest messages */
1084 s
->hello_retry_request
= 0;
1087 * For a client side resumption with no key_share we need to generate
1088 * the handshake secret (otherwise this is done during key_share
1091 if (!sent
&& !s
->server
&& !tls13_generate_handshake_secret(s
, NULL
, 0)) {
1092 *al
= SSL_AD_INTERNAL_ERROR
;
1093 SSLerr(SSL_F_FINAL_KEY_SHARE
, ERR_R_INTERNAL_ERROR
);
1101 static int init_psk_kex_modes(SSL
*s
, unsigned int context
)
1103 s
->ext
.psk_kex_mode
= TLSEXT_KEX_MODE_FLAG_NONE
;
1107 int tls_psk_do_binder(SSL
*s
, const EVP_MD
*md
, const unsigned char *msgstart
,
1108 size_t binderoffset
, const unsigned char *binderin
,
1109 unsigned char *binderout
,
1110 SSL_SESSION
*sess
, int sign
)
1112 EVP_PKEY
*mackey
= NULL
;
1113 EVP_MD_CTX
*mctx
= NULL
;
1114 unsigned char hash
[EVP_MAX_MD_SIZE
], binderkey
[EVP_MAX_MD_SIZE
];
1115 unsigned char finishedkey
[EVP_MAX_MD_SIZE
], tmpbinder
[EVP_MAX_MD_SIZE
];
1116 const char resumption_label
[] = "resumption psk binder key";
1117 size_t bindersize
, hashsize
= EVP_MD_size(md
);
1120 /* Generate the early_secret */
1121 if (!tls13_generate_secret(s
, md
, NULL
, sess
->master_key
,
1122 sess
->master_key_length
,
1123 (unsigned char *)&s
->early_secret
)) {
1124 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1129 * Create the handshake hash for the binder key...the messages so far are
1132 mctx
= EVP_MD_CTX_new();
1134 || EVP_DigestInit_ex(mctx
, md
, NULL
) <= 0
1135 || EVP_DigestFinal_ex(mctx
, hash
, NULL
) <= 0) {
1136 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1140 /* Generate the binder key */
1141 if (!tls13_hkdf_expand(s
, md
, s
->early_secret
,
1142 (unsigned char *)resumption_label
,
1143 sizeof(resumption_label
) - 1, hash
, binderkey
,
1145 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1149 /* Generate the finished key */
1150 if (!tls13_derive_finishedkey(s
, md
, binderkey
, finishedkey
, hashsize
)) {
1151 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1155 if (EVP_DigestInit_ex(mctx
, md
, NULL
) <= 0) {
1156 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1161 * Get a hash of the ClientHello up to the start of the binders. If we are
1162 * following a HelloRetryRequest then this includes the hash of the first
1163 * ClientHello and the HelloRetryRequest itself.
1165 if (s
->hello_retry_request
) {
1169 hdatalen
= BIO_get_mem_data(s
->s3
->handshake_buffer
, &hdata
);
1170 if (hdatalen
<= 0) {
1171 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, SSL_R_BAD_HANDSHAKE_LENGTH
);
1176 * For servers the handshake buffer data will include the second
1177 * ClientHello - which we don't want - so we need to take that bit off.
1180 if (hdatalen
< s
->init_num
+ SSL3_HM_HEADER_LENGTH
) {
1181 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1184 hdatalen
-= s
->init_num
+ SSL3_HM_HEADER_LENGTH
;
1187 if (EVP_DigestUpdate(mctx
, hdata
, hdatalen
) <= 0) {
1188 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1193 if (EVP_DigestUpdate(mctx
, msgstart
, binderoffset
) <= 0
1194 || EVP_DigestFinal_ex(mctx
, hash
, NULL
) <= 0) {
1195 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1199 mackey
= EVP_PKEY_new_mac_key(EVP_PKEY_HMAC
, NULL
, finishedkey
, hashsize
);
1200 if (mackey
== NULL
) {
1201 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1206 binderout
= tmpbinder
;
1208 bindersize
= hashsize
;
1209 if (EVP_DigestSignInit(mctx
, NULL
, md
, NULL
, mackey
) <= 0
1210 || EVP_DigestSignUpdate(mctx
, hash
, hashsize
) <= 0
1211 || EVP_DigestSignFinal(mctx
, binderout
, &bindersize
) <= 0
1212 || bindersize
!= hashsize
) {
1213 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1220 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1221 ret
= (CRYPTO_memcmp(binderin
, binderout
, hashsize
) == 0);
1225 OPENSSL_cleanse(binderkey
, sizeof(binderkey
));
1226 OPENSSL_cleanse(finishedkey
, sizeof(finishedkey
));
1227 EVP_PKEY_free(mackey
);
1228 EVP_MD_CTX_free(mctx
);