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
, NULL
, tls_construct_stoc_early_data_info
, NULL
, NULL
137 #ifndef OPENSSL_NO_EC
139 TLSEXT_TYPE_ec_point_formats
,
140 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
141 NULL
, tls_parse_ctos_ec_pt_formats
, tls_parse_stoc_ec_pt_formats
,
142 tls_construct_stoc_ec_pt_formats
, tls_construct_ctos_ec_pt_formats
,
146 TLSEXT_TYPE_supported_groups
,
147 EXT_CLIENT_HELLO
| EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
148 NULL
, tls_parse_ctos_supported_groups
, NULL
,
149 NULL
/* TODO(TLS1.3): Need to add this */,
150 tls_construct_ctos_supported_groups
, NULL
157 TLSEXT_TYPE_session_ticket
,
158 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
159 init_session_ticket
, tls_parse_ctos_session_ticket
,
160 tls_parse_stoc_session_ticket
, tls_construct_stoc_session_ticket
,
161 tls_construct_ctos_session_ticket
, NULL
164 TLSEXT_TYPE_signature_algorithms
,
166 init_sig_algs
, tls_parse_ctos_sig_algs
, NULL
, NULL
,
167 tls_construct_ctos_sig_algs
, final_sig_algs
169 #ifndef OPENSSL_NO_OCSP
171 TLSEXT_TYPE_status_request
,
172 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
173 | EXT_TLS1_3_CERTIFICATE
,
174 init_status_request
, tls_parse_ctos_status_request
,
175 tls_parse_stoc_status_request
, tls_construct_stoc_status_request
,
176 tls_construct_ctos_status_request
, NULL
181 #ifndef OPENSSL_NO_NEXTPROTONEG
183 TLSEXT_TYPE_next_proto_neg
,
184 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
185 init_npn
, tls_parse_ctos_npn
, tls_parse_stoc_npn
,
186 tls_construct_stoc_next_proto_neg
, tls_construct_ctos_npn
, NULL
193 * Must appear in this list after server_name so that finalisation
194 * happens after server_name callbacks
196 TLSEXT_TYPE_application_layer_protocol_negotiation
,
197 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
198 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
199 init_alpn
, tls_parse_ctos_alpn
, tls_parse_stoc_alpn
,
200 tls_construct_stoc_alpn
, tls_construct_ctos_alpn
, final_alpn
202 #ifndef OPENSSL_NO_SRTP
204 TLSEXT_TYPE_use_srtp
,
205 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
206 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
| EXT_DTLS_ONLY
,
207 init_srtp
, tls_parse_ctos_use_srtp
, tls_parse_stoc_use_srtp
,
208 tls_construct_stoc_use_srtp
, tls_construct_ctos_use_srtp
, NULL
214 TLSEXT_TYPE_encrypt_then_mac
,
215 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
| EXT_SSL3_ALLOWED
,
216 init_etm
, tls_parse_ctos_etm
, tls_parse_stoc_etm
,
217 tls_construct_stoc_etm
, tls_construct_ctos_etm
, NULL
219 #ifndef OPENSSL_NO_CT
221 TLSEXT_TYPE_signed_certificate_timestamp
,
222 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
223 | EXT_TLS1_3_CERTIFICATE
,
226 * No server side support for this, but can be provided by a custom
227 * extension. This is an exception to the rule that custom extensions
228 * cannot override built in ones.
230 NULL
, tls_parse_stoc_sct
, NULL
, tls_construct_ctos_sct
, NULL
236 TLSEXT_TYPE_extended_master_secret
,
237 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
238 init_ems
, tls_parse_ctos_ems
, tls_parse_stoc_ems
,
239 tls_construct_stoc_ems
, tls_construct_ctos_ems
, final_ems
242 TLSEXT_TYPE_supported_versions
,
243 EXT_CLIENT_HELLO
| EXT_TLS_IMPLEMENTATION_ONLY
| EXT_TLS1_3_ONLY
,
245 /* Processed inline as part of version selection */
246 NULL
, NULL
, NULL
, tls_construct_ctos_supported_versions
, NULL
249 TLSEXT_TYPE_psk_kex_modes
,
250 EXT_CLIENT_HELLO
| EXT_TLS_IMPLEMENTATION_ONLY
| EXT_TLS1_3_ONLY
,
251 init_psk_kex_modes
, tls_parse_ctos_psk_kex_modes
, NULL
, NULL
,
252 tls_construct_ctos_psk_kex_modes
, NULL
254 #ifndef OPENSSL_NO_EC
257 * Must be in this list after supported_groups. We need that to have
258 * been parsed before we do this one.
260 TLSEXT_TYPE_key_share
,
261 EXT_CLIENT_HELLO
| EXT_TLS1_3_SERVER_HELLO
262 | EXT_TLS1_3_HELLO_RETRY_REQUEST
| EXT_TLS_IMPLEMENTATION_ONLY
264 NULL
, tls_parse_ctos_key_share
, tls_parse_stoc_key_share
,
265 tls_construct_stoc_key_share
, tls_construct_ctos_key_share
,
271 * Special unsolicited ServerHello extension only used when
272 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
274 TLSEXT_TYPE_cryptopro_bug
,
275 EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
276 NULL
, NULL
, NULL
, tls_construct_stoc_cryptopro_bug
, NULL
, NULL
279 /* Must be immediately before pre_shared_key */
280 /* TODO(TLS1.3): Fix me */
284 /* We send this, but don't read it */
285 NULL
, NULL
, NULL
, tls_construct_ctos_padding
, NULL
288 /* Required by the TLSv1.3 spec to always be the last extension */
290 EXT_CLIENT_HELLO
| EXT_TLS1_3_SERVER_HELLO
| EXT_TLS_IMPLEMENTATION_ONLY
292 NULL
, tls_parse_ctos_psk
, tls_parse_stoc_psk
, tls_construct_stoc_psk
,
293 tls_construct_ctos_psk
, NULL
298 * Verify whether we are allowed to use the extension |type| in the current
299 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
300 * indicate the extension is not allowed. If returning 1 then |*found| is set to
301 * 1 if we found a definition for the extension, and |*idx| is set to its index
303 static int verify_extension(SSL
*s
, unsigned int context
, unsigned int type
,
304 custom_ext_methods
*meths
, RAW_EXTENSION
*rawexlist
,
305 RAW_EXTENSION
**found
)
308 size_t builtin_num
= OSSL_NELEM(ext_defs
);
309 const EXTENSION_DEFINITION
*thisext
;
311 for (i
= 0, thisext
= ext_defs
; i
< builtin_num
; i
++, thisext
++) {
312 if (type
== thisext
->type
) {
313 /* Check we're allowed to use this extension in this context */
314 if ((context
& thisext
->context
) == 0)
317 if (SSL_IS_DTLS(s
)) {
318 if ((thisext
->context
& EXT_TLS_ONLY
) != 0)
320 } else if ((thisext
->context
& EXT_DTLS_ONLY
) != 0) {
324 *found
= &rawexlist
[i
];
329 if ((context
& (EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
)) == 0) {
331 * Custom extensions only apply to <=TLS1.2. This extension is unknown
332 * in this context - we allow it
338 /* Check the custom extensions */
340 for (i
= builtin_num
; i
< builtin_num
+ meths
->meths_count
; i
++) {
341 if (meths
->meths
[i
- builtin_num
].ext_type
== type
) {
342 *found
= &rawexlist
[i
];
348 /* Unknown extension. We allow it */
354 * Check whether the context defined for an extension |extctx| means whether
355 * the extension is relevant for the current context |thisctx| or not. Returns
356 * 1 if the extension is relevant for this context, and 0 otherwise
358 static int extension_is_relevant(SSL
*s
, unsigned int extctx
,
359 unsigned int thisctx
)
362 && (extctx
& EXT_TLS_IMPLEMENTATION_ONLY
) != 0)
363 || (s
->version
== SSL3_VERSION
364 && (extctx
& EXT_SSL3_ALLOWED
) == 0)
366 && (extctx
& EXT_TLS1_2_AND_BELOW_ONLY
) != 0)
367 || (!SSL_IS_TLS13(s
) && (extctx
& EXT_TLS1_3_ONLY
) != 0))
374 * Gather a list of all the extensions from the data in |packet]. |context|
375 * tells us which message this extension is for. The raw extension data is
376 * stored in |*res| on success. In the event of an error the alert type to use
377 * is stored in |*al|. We don't actually process the content of the extensions
378 * yet, except to check their types. This function also runs the initialiser
379 * functions for all known extensions (whether we have collected them or not).
380 * If successful the caller is responsible for freeing the contents of |*res|.
382 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
383 * more than one extension of the same type in a ClientHello or ServerHello.
384 * This function returns 1 if all extensions are unique and we have parsed their
385 * types, and 0 if the extensions contain duplicates, could not be successfully
386 * found, or an internal error occurred. We only check duplicates for
387 * extensions that we know about. We ignore others.
389 int tls_collect_extensions(SSL
*s
, PACKET
*packet
, unsigned int context
,
390 RAW_EXTENSION
**res
, int *al
, size_t *len
)
392 PACKET extensions
= *packet
;
395 custom_ext_methods
*exts
= NULL
;
396 RAW_EXTENSION
*raw_extensions
= NULL
;
397 const EXTENSION_DEFINITION
*thisexd
;
402 * Initialise server side custom extensions. Client side is done during
403 * construction of extensions for the ClientHello.
405 if ((context
& EXT_CLIENT_HELLO
) != 0) {
406 exts
= &s
->cert
->srv_ext
;
407 custom_ext_init(&s
->cert
->srv_ext
);
408 } else if ((context
& EXT_TLS1_2_SERVER_HELLO
) != 0) {
409 exts
= &s
->cert
->cli_ext
;
412 num_exts
= OSSL_NELEM(ext_defs
) + (exts
!= NULL
? exts
->meths_count
: 0);
413 raw_extensions
= OPENSSL_zalloc(num_exts
* sizeof(*raw_extensions
));
414 if (raw_extensions
== NULL
) {
415 *al
= SSL_AD_INTERNAL_ERROR
;
416 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS
, ERR_R_MALLOC_FAILURE
);
420 while (PACKET_remaining(&extensions
) > 0) {
423 RAW_EXTENSION
*thisex
;
425 if (!PACKET_get_net_2(&extensions
, &type
) ||
426 !PACKET_get_length_prefixed_2(&extensions
, &extension
)) {
427 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS
, SSL_R_BAD_EXTENSION
);
428 *al
= SSL_AD_DECODE_ERROR
;
432 * Verify this extension is allowed. We only check duplicates for
433 * extensions that we recognise.
435 if (!verify_extension(s
, context
, type
, exts
, raw_extensions
, &thisex
)
436 || (thisex
!= NULL
&& thisex
->present
== 1)) {
437 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS
, SSL_R_BAD_EXTENSION
);
438 *al
= SSL_AD_ILLEGAL_PARAMETER
;
441 if (thisex
!= NULL
) {
442 thisex
->data
= extension
;
449 * Initialise all known extensions relevant to this context, whether we have
452 for (thisexd
= ext_defs
, i
= 0; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
453 if(thisexd
->init
!= NULL
&& (thisexd
->context
& context
) != 0
454 && extension_is_relevant(s
, thisexd
->context
, context
)
455 && !thisexd
->init(s
, context
)) {
456 *al
= SSL_AD_INTERNAL_ERROR
;
461 *res
= raw_extensions
;
467 OPENSSL_free(raw_extensions
);
472 * Runs the parser for a given extension with index |idx|. |exts| contains the
473 * list of all parsed extensions previously collected by
474 * tls_collect_extensions(). The parser is only run if it is applicable for the
475 * given |context| and the parser has not already been run. If this is for a
476 * Certificate message, then we also provide the parser with the relevant
477 * Certificate |x| and its position in the |chainidx| with 0 being the first
478 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
479 * |*al| is populated with a suitable alert code. If an extension is not present
480 * this counted as success.
482 int tls_parse_extension(SSL
*s
, TLSEXT_INDEX idx
, int context
,
483 RAW_EXTENSION
*exts
, X509
*x
, size_t chainidx
, int *al
)
485 RAW_EXTENSION
*currext
= &exts
[idx
];
486 int (*parser
)(SSL
*s
, PACKET
*pkt
, unsigned int context
, X509
*x
,
487 size_t chainidx
, int *al
) = NULL
;
489 /* Skip if the extension is not present */
490 if (!currext
->present
)
494 s
->ext
.debug_cb(s
, !s
->server
, currext
->type
,
495 PACKET_data(&currext
->data
),
496 PACKET_remaining(&currext
->data
),
499 /* Skip if we've already parsed this extension */
505 if (idx
< OSSL_NELEM(ext_defs
)) {
506 /* We are handling a built-in extension */
507 const EXTENSION_DEFINITION
*extdef
= &ext_defs
[idx
];
509 /* Check if extension is defined for our protocol. If not, skip */
510 if (!extension_is_relevant(s
, extdef
->context
, context
))
513 parser
= s
->server
? extdef
->parse_ctos
: extdef
->parse_stoc
;
516 return parser(s
, &currext
->data
, context
, x
, chainidx
, al
);
519 * If the parser is NULL we fall through to the custom extension
525 * This is a custom extension. We only allow this if it is a non
526 * resumed session on the server side.
528 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
529 * We're going to need a new mechanism for TLS1.3 to specify which
530 * messages to add the custom extensions to.
532 if ((!s
->hit
|| !s
->server
)
534 & (EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
)) != 0
535 && custom_ext_parse(s
, s
->server
, currext
->type
,
536 PACKET_data(&currext
->data
),
537 PACKET_remaining(&currext
->data
),
545 * Parse all remaining extensions that have not yet been parsed. Also calls the
546 * finalisation for all extensions at the end, whether we collected them or not.
547 * Returns 1 for success or 0 for failure. If we are working on a Certificate
548 * message then we also pass the Certificate |x| and its position in the
549 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
550 * populated with a suitable alert code.
552 int tls_parse_all_extensions(SSL
*s
, int context
, RAW_EXTENSION
*exts
, X509
*x
,
553 size_t chainidx
, int *al
)
555 size_t i
, numexts
= OSSL_NELEM(ext_defs
);
556 const EXTENSION_DEFINITION
*thisexd
;
558 /* Calculate the number of extensions in the extensions list */
559 if ((context
& EXT_CLIENT_HELLO
) != 0) {
560 numexts
+= s
->cert
->srv_ext
.meths_count
;
561 } else if ((context
& EXT_TLS1_2_SERVER_HELLO
) != 0) {
562 numexts
+= s
->cert
->cli_ext
.meths_count
;
565 /* Parse each extension in turn */
566 for (i
= 0; i
< numexts
; i
++) {
567 if (!tls_parse_extension(s
, i
, context
, exts
, x
, chainidx
, al
))
572 * Finalise all known extensions relevant to this context, whether we have
575 for (i
= 0, thisexd
= ext_defs
; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
576 if(thisexd
->final
!= NULL
577 && (thisexd
->context
& context
) != 0
578 && !thisexd
->final(s
, context
, exts
[i
].present
, al
))
586 * Construct all the extensions relevant to the current |context| and write
587 * them to |pkt|. If this is an extension for a Certificate in a Certificate
588 * message, then |x| will be set to the Certificate we are handling, and
589 * |chainidx| will indicate the position in the chainidx we are processing (with
590 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
591 * failure occurs then |al| is populated with a suitable alert code. On a
592 * failure construction stops at the first extension to fail to construct.
594 int tls_construct_extensions(SSL
*s
, WPACKET
*pkt
, unsigned int context
,
595 X509
*x
, size_t chainidx
, int *al
)
598 int addcustom
= 0, min_version
, max_version
= 0, reason
, tmpal
;
599 const EXTENSION_DEFINITION
*thisexd
;
602 * Normally if something goes wrong during construction it's an internal
603 * error. We can always override this later.
605 tmpal
= SSL_AD_INTERNAL_ERROR
;
607 if (!WPACKET_start_sub_packet_u16(pkt
)
609 * If extensions are of zero length then we don't even add the
610 * extensions length bytes to a ClientHello/ServerHello in SSLv3
612 || ((context
& (EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
)) != 0
613 && s
->version
== SSL3_VERSION
614 && !WPACKET_set_flags(pkt
,
615 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH
))) {
616 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, ERR_R_INTERNAL_ERROR
);
620 if ((context
& EXT_CLIENT_HELLO
) != 0) {
621 reason
= ssl_get_client_min_max_version(s
, &min_version
, &max_version
);
623 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, reason
);
628 /* Add custom extensions first */
629 if ((context
& EXT_CLIENT_HELLO
) != 0) {
630 custom_ext_init(&s
->cert
->cli_ext
);
632 } else if ((context
& EXT_TLS1_2_SERVER_HELLO
) != 0) {
634 * We already initialised the custom extensions during ClientHello
637 * TODO(TLS1.3): We're going to need a new custom extension mechanism
638 * for TLS1.3, so that custom extensions can specify which of the
639 * multiple message they wish to add themselves to.
644 if (addcustom
&& !custom_ext_add(s
, s
->server
, pkt
, &tmpal
)) {
645 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, ERR_R_INTERNAL_ERROR
);
649 for (i
= 0, thisexd
= ext_defs
; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
650 int (*construct
)(SSL
*s
, WPACKET
*pkt
, unsigned int context
, X509
*x
,
651 size_t chainidx
, int *al
);
653 /* Skip if not relevant for our context */
654 if ((thisexd
->context
& context
) == 0)
657 construct
= s
->server
? thisexd
->construct_stoc
658 : thisexd
->construct_ctos
;
660 /* Check if this extension is defined for our protocol. If not, skip */
662 && (thisexd
->context
& EXT_TLS_IMPLEMENTATION_ONLY
)
664 || (s
->version
== SSL3_VERSION
665 && (thisexd
->context
& EXT_SSL3_ALLOWED
) == 0)
667 && (thisexd
->context
& EXT_TLS1_2_AND_BELOW_ONLY
)
670 && (thisexd
->context
& EXT_TLS1_3_ONLY
) != 0
671 && (context
& EXT_CLIENT_HELLO
) == 0)
672 || ((thisexd
->context
& EXT_TLS1_3_ONLY
) != 0
673 && (context
& EXT_CLIENT_HELLO
) != 0
674 && (SSL_IS_DTLS(s
) || max_version
< TLS1_3_VERSION
))
675 || construct
== NULL
)
678 if (!construct(s
, pkt
, context
, x
, chainidx
, &tmpal
))
682 if (!WPACKET_close(pkt
)) {
683 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, ERR_R_INTERNAL_ERROR
);
695 * Built in extension finalisation and initialisation functions. All initialise
696 * or finalise the associated extension type for the given |context|. For
697 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
698 * otherwise. These functions return 1 on success or 0 on failure. In the event
699 * of a failure then |*al| is populated with a suitable error code.
702 static int final_renegotiate(SSL
*s
, unsigned int context
, int sent
,
707 * Check if we can connect to a server that doesn't support safe
710 if (!(s
->options
& SSL_OP_LEGACY_SERVER_CONNECT
)
711 && !(s
->options
& SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
)
713 *al
= SSL_AD_HANDSHAKE_FAILURE
;
714 SSLerr(SSL_F_FINAL_RENEGOTIATE
,
715 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED
);
722 /* Need RI if renegotiating */
724 && !(s
->options
& SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
)
726 *al
= SSL_AD_HANDSHAKE_FAILURE
;
727 SSLerr(SSL_F_FINAL_RENEGOTIATE
,
728 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED
);
736 static int init_server_name(SSL
*s
, unsigned int context
)
739 s
->servername_done
= 0;
744 static int final_server_name(SSL
*s
, unsigned int context
, int sent
,
747 int ret
= SSL_TLSEXT_ERR_NOACK
;
748 int altmp
= SSL_AD_UNRECOGNIZED_NAME
;
750 if (s
->ctx
!= NULL
&& s
->ctx
->ext
.servername_cb
!= 0)
751 ret
= s
->ctx
->ext
.servername_cb(s
, &altmp
,
752 s
->ctx
->ext
.servername_arg
);
753 else if (s
->session_ctx
!= NULL
754 && s
->session_ctx
->ext
.servername_cb
!= 0)
755 ret
= s
->session_ctx
->ext
.servername_cb(s
, &altmp
,
756 s
->session_ctx
->ext
.servername_arg
);
759 case SSL_TLSEXT_ERR_ALERT_FATAL
:
763 case SSL_TLSEXT_ERR_ALERT_WARNING
:
767 case SSL_TLSEXT_ERR_NOACK
:
768 s
->servername_done
= 0;
776 #ifndef OPENSSL_NO_EC
777 static int final_ec_pt_formats(SSL
*s
, unsigned int context
, int sent
,
780 unsigned long alg_k
, alg_a
;
785 alg_k
= s
->s3
->tmp
.new_cipher
->algorithm_mkey
;
786 alg_a
= s
->s3
->tmp
.new_cipher
->algorithm_auth
;
789 * If we are client and using an elliptic curve cryptography cipher
790 * suite, then if server returns an EC point formats lists extension it
791 * must contain uncompressed.
793 if (s
->ext
.ecpointformats
!= NULL
794 && s
->ext
.ecpointformats_len
> 0
795 && s
->session
->ext
.ecpointformats
!= NULL
796 && s
->session
->ext
.ecpointformats_len
> 0
797 && ((alg_k
& SSL_kECDHE
) || (alg_a
& SSL_aECDSA
))) {
798 /* we are using an ECC cipher */
800 unsigned char *list
= s
->session
->ext
.ecpointformats
;
802 for (i
= 0; i
< s
->session
->ext
.ecpointformats_len
; i
++) {
803 if (*list
++ == TLSEXT_ECPOINTFORMAT_uncompressed
)
806 if (i
== s
->session
->ext
.ecpointformats_len
) {
807 SSLerr(SSL_F_FINAL_EC_PT_FORMATS
,
808 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST
);
817 static int init_session_ticket(SSL
*s
, unsigned int context
)
820 s
->ext
.ticket_expected
= 0;
825 #ifndef OPENSSL_NO_OCSP
826 static int init_status_request(SSL
*s
, unsigned int context
)
829 s
->ext
.status_type
= TLSEXT_STATUSTYPE_nothing
;
832 * Ensure we get sensible values passed to tlsext_status_cb in the event
833 * that we don't receive a status message
835 OPENSSL_free(s
->ext
.ocsp
.resp
);
836 s
->ext
.ocsp
.resp
= NULL
;
837 s
->ext
.ocsp
.resp_len
= 0;
844 #ifndef OPENSSL_NO_NEXTPROTONEG
845 static int init_npn(SSL
*s
, unsigned int context
)
853 static int init_alpn(SSL
*s
, unsigned int context
)
855 OPENSSL_free(s
->s3
->alpn_selected
);
856 s
->s3
->alpn_selected
= NULL
;
858 s
->s3
->alpn_selected_len
= 0;
859 OPENSSL_free(s
->s3
->alpn_proposed
);
860 s
->s3
->alpn_proposed
= NULL
;
861 s
->s3
->alpn_proposed_len
= 0;
866 static int final_alpn(SSL
*s
, unsigned int context
, int sent
, int *al
)
868 const unsigned char *selected
= NULL
;
869 unsigned char selected_len
= 0;
874 if (s
->ctx
->ext
.alpn_select_cb
!= NULL
&& s
->s3
->alpn_proposed
!= NULL
) {
875 int r
= s
->ctx
->ext
.alpn_select_cb(s
, &selected
, &selected_len
,
876 s
->s3
->alpn_proposed
,
877 (unsigned int)s
->s3
->alpn_proposed_len
,
878 s
->ctx
->ext
.alpn_select_cb_arg
);
880 if (r
== SSL_TLSEXT_ERR_OK
) {
881 OPENSSL_free(s
->s3
->alpn_selected
);
882 s
->s3
->alpn_selected
= OPENSSL_memdup(selected
, selected_len
);
883 if (s
->s3
->alpn_selected
== NULL
) {
884 *al
= SSL_AD_INTERNAL_ERROR
;
887 s
->s3
->alpn_selected_len
= selected_len
;
888 #ifndef OPENSSL_NO_NEXTPROTONEG
889 /* ALPN takes precedence over NPN. */
893 *al
= SSL_AD_NO_APPLICATION_PROTOCOL
;
901 static int init_sig_algs(SSL
*s
, unsigned int context
)
903 /* Clear any signature algorithms extension received */
904 OPENSSL_free(s
->s3
->tmp
.peer_sigalgs
);
905 s
->s3
->tmp
.peer_sigalgs
= NULL
;
910 #ifndef OPENSSL_NO_SRP
911 static int init_srp(SSL
*s
, unsigned int context
)
913 OPENSSL_free(s
->srp_ctx
.login
);
914 s
->srp_ctx
.login
= NULL
;
920 static int init_etm(SSL
*s
, unsigned int context
)
927 static int init_ems(SSL
*s
, unsigned int context
)
930 s
->s3
->flags
&= ~TLS1_FLAGS_RECEIVED_EXTMS
;
935 static int final_ems(SSL
*s
, unsigned int context
, int sent
, int *al
)
937 if (!s
->server
&& s
->hit
) {
939 * Check extended master secret extension is consistent with
942 if (!(s
->s3
->flags
& TLS1_FLAGS_RECEIVED_EXTMS
) !=
943 !(s
->session
->flags
& SSL_SESS_FLAG_EXTMS
)) {
944 *al
= SSL_AD_HANDSHAKE_FAILURE
;
945 SSLerr(SSL_F_FINAL_EMS
, SSL_R_INCONSISTENT_EXTMS
);
953 #ifndef OPENSSL_NO_SRTP
954 static int init_srtp(SSL
*s
, unsigned int context
)
957 s
->srtp_profile
= NULL
;
963 static int final_sig_algs(SSL
*s
, unsigned int context
, int sent
, int *al
)
965 if (!sent
&& SSL_IS_TLS13(s
)) {
966 *al
= TLS13_AD_MISSING_EXTENSION
;
967 SSLerr(SSL_F_FINAL_SIG_ALGS
, SSL_R_MISSING_SIGALGS_EXTENSION
);
974 #ifndef OPENSSL_NO_EC
975 static int final_key_share(SSL
*s
, unsigned int context
, int sent
, int *al
)
977 if (!SSL_IS_TLS13(s
))
984 * we have no key_share
986 * (we are not resuming
987 * OR the kex_mode doesn't allow non key_share resumes)
994 || (s
->ext
.psk_kex_mode
& TLSEXT_KEX_MODE_FLAG_KE
) == 0)) {
995 /* Nothing left we can do - just fail */
996 *al
= SSL_AD_HANDSHAKE_FAILURE
;
997 SSLerr(SSL_F_FINAL_KEY_SHARE
, SSL_R_NO_SUITABLE_KEY_SHARE
);
1004 * we have no key_share
1007 * we didn't already send a HelloRetryRequest
1009 * the client sent a key_share extension
1011 * (we are not resuming
1012 * OR the kex_mode allows key_share resumes)
1014 * a shared group exists
1016 * send a HelloRetryRequest
1018 * we are not resuming
1020 * the kex_mode doesn't allow non key_share resumes
1024 if (s
->server
&& s
->s3
->peer_tmp
== NULL
) {
1025 /* No suitable share */
1026 if (s
->hello_retry_request
== 0 && sent
1028 || (s
->ext
.psk_kex_mode
& TLSEXT_KEX_MODE_FLAG_KE_DHE
)
1030 const unsigned char *pcurves
, *pcurvestmp
, *clntcurves
;
1031 size_t num_curves
, clnt_num_curves
, i
;
1032 unsigned int group_id
= 0;
1034 /* Check if a shared group exists */
1036 /* Get the clients list of supported groups. */
1037 if (!tls1_get_curvelist(s
, 1, &clntcurves
, &clnt_num_curves
)) {
1038 *al
= SSL_AD_INTERNAL_ERROR
;
1039 SSLerr(SSL_F_FINAL_KEY_SHARE
, ERR_R_INTERNAL_ERROR
);
1043 /* Get our list of available groups */
1044 if (!tls1_get_curvelist(s
, 0, &pcurves
, &num_curves
)) {
1045 *al
= SSL_AD_INTERNAL_ERROR
;
1046 SSLerr(SSL_F_FINAL_KEY_SHARE
, ERR_R_INTERNAL_ERROR
);
1050 /* Find the first group we allow that is also in client's list */
1051 for (i
= 0, pcurvestmp
= pcurves
; i
< num_curves
;
1052 i
++, pcurvestmp
+= 2) {
1053 group_id
= bytestogroup(pcurvestmp
);
1055 if (check_in_list(s
, group_id
, clntcurves
, clnt_num_curves
, 1))
1059 if (i
< num_curves
) {
1060 /* A shared group exists so send a HelloRetryRequest */
1061 s
->s3
->group_id
= group_id
;
1062 s
->hello_retry_request
= 1;
1067 || (s
->ext
.psk_kex_mode
& TLSEXT_KEX_MODE_FLAG_KE
) == 0) {
1068 /* Nothing left we can do - just fail */
1069 *al
= SSL_AD_HANDSHAKE_FAILURE
;
1070 SSLerr(SSL_F_FINAL_KEY_SHARE
, SSL_R_NO_SUITABLE_KEY_SHARE
);
1075 /* We have a key_share so don't send any more HelloRetryRequest messages */
1077 s
->hello_retry_request
= 0;
1080 * For a client side resumption with no key_share we need to generate
1081 * the handshake secret (otherwise this is done during key_share
1084 if (!sent
&& !s
->server
&& !tls13_generate_handshake_secret(s
, NULL
, 0)) {
1085 *al
= SSL_AD_INTERNAL_ERROR
;
1086 SSLerr(SSL_F_FINAL_KEY_SHARE
, ERR_R_INTERNAL_ERROR
);
1094 static int init_psk_kex_modes(SSL
*s
, unsigned int context
)
1096 s
->ext
.psk_kex_mode
= TLSEXT_KEX_MODE_FLAG_NONE
;
1100 int tls_psk_do_binder(SSL
*s
, const EVP_MD
*md
, const unsigned char *msgstart
,
1101 size_t binderoffset
, const unsigned char *binderin
,
1102 unsigned char *binderout
,
1103 SSL_SESSION
*sess
, int sign
)
1105 EVP_PKEY
*mackey
= NULL
;
1106 EVP_MD_CTX
*mctx
= NULL
;
1107 unsigned char hash
[EVP_MAX_MD_SIZE
], binderkey
[EVP_MAX_MD_SIZE
];
1108 unsigned char finishedkey
[EVP_MAX_MD_SIZE
], tmpbinder
[EVP_MAX_MD_SIZE
];
1109 const char resumption_label
[] = "resumption psk binder key";
1110 size_t bindersize
, hashsize
= EVP_MD_size(md
);
1113 /* Generate the early_secret */
1114 if (!tls13_generate_secret(s
, md
, NULL
, sess
->master_key
,
1115 sess
->master_key_length
,
1116 (unsigned char *)&s
->early_secret
)) {
1117 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1122 * Create the handshake hash for the binder key...the messages so far are
1125 mctx
= EVP_MD_CTX_new();
1127 || EVP_DigestInit_ex(mctx
, md
, NULL
) <= 0
1128 || EVP_DigestFinal_ex(mctx
, hash
, NULL
) <= 0) {
1129 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1133 /* Generate the binder key */
1134 if (!tls13_hkdf_expand(s
, md
, s
->early_secret
,
1135 (unsigned char *)resumption_label
,
1136 sizeof(resumption_label
) - 1, hash
, binderkey
,
1138 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1142 /* Generate the finished key */
1143 if (!tls13_derive_finishedkey(s
, md
, binderkey
, finishedkey
, hashsize
)) {
1144 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1148 if (EVP_DigestInit_ex(mctx
, md
, NULL
) <= 0) {
1149 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1154 * Get a hash of the ClientHello up to the start of the binders. If we are
1155 * following a HelloRetryRequest then this includes the hash of the first
1156 * ClientHello and the HelloRetryRequest itself.
1158 if (s
->hello_retry_request
) {
1162 hdatalen
= BIO_get_mem_data(s
->s3
->handshake_buffer
, &hdata
);
1163 if (hdatalen
<= 0) {
1164 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, SSL_R_BAD_HANDSHAKE_LENGTH
);
1169 * For servers the handshake buffer data will include the second
1170 * ClientHello - which we don't want - so we need to take that bit off.
1173 if (hdatalen
< s
->init_num
+ SSL3_HM_HEADER_LENGTH
) {
1174 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1177 hdatalen
-= s
->init_num
+ SSL3_HM_HEADER_LENGTH
;
1180 if (EVP_DigestUpdate(mctx
, hdata
, hdatalen
) <= 0) {
1181 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1186 if (EVP_DigestUpdate(mctx
, msgstart
, binderoffset
) <= 0
1187 || EVP_DigestFinal_ex(mctx
, hash
, NULL
) <= 0) {
1188 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1192 mackey
= EVP_PKEY_new_mac_key(EVP_PKEY_HMAC
, NULL
, finishedkey
, hashsize
);
1193 if (mackey
== NULL
) {
1194 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1199 binderout
= tmpbinder
;
1201 bindersize
= hashsize
;
1202 if (EVP_DigestSignInit(mctx
, NULL
, md
, NULL
, mackey
) <= 0
1203 || EVP_DigestSignUpdate(mctx
, hash
, hashsize
) <= 0
1204 || EVP_DigestSignFinal(mctx
, binderout
, &bindersize
) <= 0
1205 || bindersize
!= hashsize
) {
1206 SSLerr(SSL_F_TLS_PSK_DO_BINDER
, ERR_R_INTERNAL_ERROR
);
1213 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1214 ret
= (CRYPTO_memcmp(binderin
, binderout
, hashsize
) == 0);
1218 OPENSSL_cleanse(binderkey
, sizeof(binderkey
));
1219 OPENSSL_cleanse(finishedkey
, sizeof(finishedkey
));
1220 EVP_PKEY_free(mackey
);
1221 EVP_MD_CTX_free(mctx
);