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
);
39 #ifndef OPENSSL_NO_SRTP
40 static int init_srtp(SSL
*s
, unsigned int context
);
42 static int final_sig_algs(SSL
*s
, unsigned int context
, int sent
, int *al
);
44 /* Structure to define a built-in extension */
45 typedef struct extensions_definition_st
{
46 /* The defined type for the extension */
49 * The context that this extension applies to, e.g. what messages and
54 * Initialise extension before parsing. Always called for relevant contexts
55 * even if extension not present
57 int (*init
)(SSL
*s
, unsigned int context
);
58 /* Parse extension sent from client to server */
59 int (*parse_ctos
)(SSL
*s
, PACKET
*pkt
, X509
*x
, size_t chainidx
, int *al
);
60 /* Parse extension send from server to client */
61 int (*parse_stoc
)(SSL
*s
, PACKET
*pkt
, X509
*x
, size_t chainidx
, int *al
);
62 /* Construct extension sent from server to client */
63 int (*construct_stoc
)(SSL
*s
, WPACKET
*pkt
, X509
*x
, size_t chainidx
,
65 /* Construct extension sent from client to server */
66 int (*construct_ctos
)(SSL
*s
, WPACKET
*pkt
, X509
*x
, size_t chainidx
,
69 * Finalise extension after parsing. Always called where an extensions was
70 * initialised even if the extension was not present. |sent| is set to 1 if
71 * the extension was seen, or 0 otherwise.
73 int (*final
)(SSL
*s
, unsigned int context
, int sent
, int *al
);
74 } EXTENSION_DEFINITION
;
77 * Definitions of all built-in extensions. NOTE: Changes in the number or order
78 * of these extensions should be mirrored with equivalent changes to the
79 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
80 * Each extension has an initialiser, a client and
81 * server side parser and a finaliser. The initialiser is called (if the
82 * extension is relevant to the given context) even if we did not see the
83 * extension in the message that we received. The parser functions are only
84 * called if we see the extension in the message. The finalisers are always
85 * called if the initialiser was called.
86 * There are also server and client side constructor functions which are always
87 * called during message construction if the extension is relevant for the
89 * The initialisation, parsing, finalisation and construction functions are
90 * always called in the order defined in this list. Some extensions may depend
91 * on others having been processed first, so the order of this list is
93 * The extension context is defined by a series of flags which specify which
94 * messages the extension is relevant to. These flags also specify whether the
95 * extension is relevant to a particular protocol or protocol version.
97 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
99 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
100 static const EXTENSION_DEFINITION ext_defs
[] = {
102 TLSEXT_TYPE_renegotiate
,
103 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_SSL3_ALLOWED
104 | EXT_TLS1_2_AND_BELOW_ONLY
,
105 NULL
, tls_parse_ctos_renegotiate
, tls_parse_stoc_renegotiate
,
106 tls_construct_stoc_renegotiate
, tls_construct_ctos_renegotiate
,
110 TLSEXT_TYPE_server_name
,
111 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
112 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
114 tls_parse_ctos_server_name
, tls_parse_stoc_server_name
,
115 tls_construct_stoc_server_name
, tls_construct_ctos_server_name
,
118 #ifndef OPENSSL_NO_SRP
121 EXT_CLIENT_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
122 init_srp
, tls_parse_ctos_srp
, NULL
, NULL
, tls_construct_ctos_srp
, NULL
127 #ifndef OPENSSL_NO_EC
129 TLSEXT_TYPE_ec_point_formats
,
130 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
131 NULL
, tls_parse_ctos_ec_pt_formats
, tls_parse_stoc_ec_pt_formats
,
132 tls_construct_stoc_ec_pt_formats
, tls_construct_ctos_ec_pt_formats
,
136 TLSEXT_TYPE_supported_groups
,
137 EXT_CLIENT_HELLO
| EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
138 NULL
, tls_parse_ctos_supported_groups
, NULL
,
139 NULL
/* TODO(TLS1.3): Need to add this */,
140 tls_construct_ctos_supported_groups
, NULL
147 TLSEXT_TYPE_session_ticket
,
148 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
149 init_session_ticket
, tls_parse_ctos_session_ticket
,
150 tls_parse_stoc_session_ticket
, tls_construct_stoc_session_ticket
,
151 tls_construct_ctos_session_ticket
, NULL
154 TLSEXT_TYPE_signature_algorithms
,
156 init_sig_algs
, tls_parse_ctos_sig_algs
, NULL
, NULL
,
157 tls_construct_ctos_sig_algs
, final_sig_algs
159 #ifndef OPENSSL_NO_OCSP
161 TLSEXT_TYPE_status_request
,
162 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
163 | EXT_TLS1_3_CERTIFICATE
,
164 init_status_request
, tls_parse_ctos_status_request
,
165 tls_parse_stoc_status_request
, tls_construct_stoc_status_request
,
166 tls_construct_ctos_status_request
, NULL
171 #ifndef OPENSSL_NO_NEXTPROTONEG
173 TLSEXT_TYPE_next_proto_neg
,
174 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
175 init_npn
, tls_parse_ctos_npn
, tls_parse_stoc_npn
,
176 tls_construct_stoc_next_proto_neg
, tls_construct_ctos_npn
, NULL
183 * Must appear in this list after server_name so that finalisation
184 * happens after server_name callbacks
186 TLSEXT_TYPE_application_layer_protocol_negotiation
,
187 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
188 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
189 init_alpn
, tls_parse_ctos_alpn
, tls_parse_stoc_alpn
,
190 tls_construct_stoc_alpn
, tls_construct_ctos_alpn
, final_alpn
192 #ifndef OPENSSL_NO_SRTP
194 TLSEXT_TYPE_use_srtp
,
195 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
196 | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
| EXT_DTLS_ONLY
,
197 init_srtp
, tls_parse_ctos_use_srtp
, tls_parse_stoc_use_srtp
,
198 tls_construct_stoc_use_srtp
, tls_construct_ctos_use_srtp
, NULL
204 TLSEXT_TYPE_encrypt_then_mac
,
205 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
206 init_etm
, tls_parse_ctos_etm
, tls_parse_stoc_etm
,
207 tls_construct_stoc_etm
, tls_construct_ctos_etm
, NULL
209 #ifndef OPENSSL_NO_CT
211 TLSEXT_TYPE_signed_certificate_timestamp
,
212 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
213 | EXT_TLS1_3_CERTIFICATE
,
216 * No server side support for this, but can be provided by a custom
217 * extension. This is an exception to the rule that custom extensions
218 * cannot override built in ones.
220 NULL
, tls_parse_stoc_sct
, NULL
, tls_construct_ctos_sct
, NULL
226 TLSEXT_TYPE_extended_master_secret
,
227 EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
228 init_ems
, tls_parse_ctos_ems
, tls_parse_stoc_ems
,
229 tls_construct_stoc_ems
, tls_construct_ctos_ems
, final_ems
232 TLSEXT_TYPE_supported_versions
,
233 EXT_CLIENT_HELLO
| EXT_TLS_IMPLEMENTATION_ONLY
| EXT_TLS1_3_ONLY
,
235 /* Processed inline as part of version selection */
236 NULL
, NULL
, NULL
, tls_construct_ctos_supported_versions
, NULL
239 /* Must be before key_share */
240 TLSEXT_TYPE_psk_kex_modes
,
241 EXT_CLIENT_HELLO
| EXT_TLS_IMPLEMENTATION_ONLY
| EXT_TLS1_3_ONLY
,
242 init_psk_kex_modes
, tls_parse_ctos_psk_kex_modes
, NULL
, NULL
,
243 tls_construct_ctos_psk_kex_modes
, NULL
247 * Must be in this list after supported_groups. We need that to have
248 * been parsed before we do this one.
250 TLSEXT_TYPE_key_share
,
251 EXT_CLIENT_HELLO
| EXT_TLS1_3_SERVER_HELLO
252 | EXT_TLS1_3_HELLO_RETRY_REQUEST
| EXT_TLS_IMPLEMENTATION_ONLY
254 NULL
, tls_parse_ctos_key_share
, tls_parse_stoc_key_share
,
255 tls_construct_stoc_key_share
, tls_construct_ctos_key_share
, NULL
259 * Special unsolicited ServerHello extension only used when
260 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set
262 TLSEXT_TYPE_cryptopro_bug
,
263 EXT_TLS1_2_SERVER_HELLO
| EXT_TLS1_2_AND_BELOW_ONLY
,
264 NULL
, NULL
, NULL
, tls_construct_stoc_cryptopro_bug
, NULL
, NULL
267 /* Must be immediately before pre_shared_key */
268 /* TODO(TLS1.3): Fix me */
272 /* We send this, but don't read it */
273 NULL
, NULL
, NULL
, tls_construct_ctos_padding
, NULL
276 /* Required by the TLSv1.3 spec to always be the last extension */
278 EXT_CLIENT_HELLO
| EXT_TLS1_3_SERVER_HELLO
| EXT_TLS_IMPLEMENTATION_ONLY
280 NULL
, NULL
, NULL
, NULL
, tls_construct_ctos_psk
, NULL
285 * Verify whether we are allowed to use the extension |type| in the current
286 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
287 * indicate the extension is not allowed. If returning 1 then |*found| is set to
288 * 1 if we found a definition for the extension, and |*idx| is set to its index
290 static int verify_extension(SSL
*s
, unsigned int context
, unsigned int type
,
291 custom_ext_methods
*meths
, RAW_EXTENSION
*rawexlist
,
292 RAW_EXTENSION
**found
)
295 size_t builtin_num
= OSSL_NELEM(ext_defs
);
296 const EXTENSION_DEFINITION
*thisext
;
298 for (i
= 0, thisext
= ext_defs
; i
< builtin_num
; i
++, thisext
++) {
299 if (type
== thisext
->type
) {
300 /* Check we're allowed to use this extension in this context */
301 if ((context
& thisext
->context
) == 0)
304 if (SSL_IS_DTLS(s
)) {
305 if ((thisext
->context
& EXT_TLS_ONLY
) != 0)
307 } else if ((thisext
->context
& EXT_DTLS_ONLY
) != 0) {
311 *found
= &rawexlist
[i
];
316 if ((context
& (EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
)) == 0) {
318 * Custom extensions only apply to <=TLS1.2. This extension is unknown
319 * in this context - we allow it
325 /* Check the custom extensions */
327 for (i
= builtin_num
; i
< builtin_num
+ meths
->meths_count
; i
++) {
328 if (meths
->meths
[i
- builtin_num
].ext_type
== type
) {
329 *found
= &rawexlist
[i
];
335 /* Unknown extension. We allow it */
341 * Check whether the context defined for an extension |extctx| means whether
342 * the extension is relevant for the current context |thisctx| or not. Returns
343 * 1 if the extension is relevant for this context, and 0 otherwise
345 static int extension_is_relevant(SSL
*s
, unsigned int extctx
,
346 unsigned int thisctx
)
349 && (extctx
& EXT_TLS_IMPLEMENTATION_ONLY
) != 0)
350 || (s
->version
== SSL3_VERSION
351 && (extctx
& EXT_SSL3_ALLOWED
) == 0)
353 && (extctx
& EXT_TLS1_2_AND_BELOW_ONLY
) != 0)
354 || (!SSL_IS_TLS13(s
) && (extctx
& EXT_TLS1_3_ONLY
) != 0))
361 * Gather a list of all the extensions from the data in |packet]. |context|
362 * tells us which message this extension is for. The raw extension data is
363 * stored in |*res| on success. In the event of an error the alert type to use
364 * is stored in |*al|. We don't actually process the content of the extensions
365 * yet, except to check their types. This function also runs the initialiser
366 * functions for all known extensions (whether we have collected them or not).
367 * If successful the caller is responsible for freeing the contents of |*res|.
369 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
370 * more than one extension of the same type in a ClientHello or ServerHello.
371 * This function returns 1 if all extensions are unique and we have parsed their
372 * types, and 0 if the extensions contain duplicates, could not be successfully
373 * found, or an internal error occurred. We only check duplicates for
374 * extensions that we know about. We ignore others.
376 int tls_collect_extensions(SSL
*s
, PACKET
*packet
, unsigned int context
,
377 RAW_EXTENSION
**res
, int *al
)
379 PACKET extensions
= *packet
;
381 custom_ext_methods
*exts
= NULL
;
382 RAW_EXTENSION
*raw_extensions
= NULL
;
383 const EXTENSION_DEFINITION
*thisexd
;
388 * Initialise server side custom extensions. Client side is done during
389 * construction of extensions for the ClientHello.
391 if ((context
& EXT_CLIENT_HELLO
) != 0) {
392 exts
= &s
->cert
->srv_ext
;
393 custom_ext_init(&s
->cert
->srv_ext
);
394 } else if ((context
& EXT_TLS1_2_SERVER_HELLO
) != 0) {
395 exts
= &s
->cert
->cli_ext
;
398 raw_extensions
= OPENSSL_zalloc((OSSL_NELEM(ext_defs
)
399 + (exts
!= NULL
? exts
->meths_count
: 0))
400 * sizeof(*raw_extensions
));
401 if (raw_extensions
== NULL
) {
402 *al
= SSL_AD_INTERNAL_ERROR
;
403 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS
, ERR_R_MALLOC_FAILURE
);
407 while (PACKET_remaining(&extensions
) > 0) {
410 RAW_EXTENSION
*thisex
;
412 if (!PACKET_get_net_2(&extensions
, &type
) ||
413 !PACKET_get_length_prefixed_2(&extensions
, &extension
)) {
414 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS
, SSL_R_BAD_EXTENSION
);
415 *al
= SSL_AD_DECODE_ERROR
;
419 * Verify this extension is allowed. We only check duplicates for
420 * extensions that we recognise.
422 if (!verify_extension(s
, context
, type
, exts
, raw_extensions
, &thisex
)
423 || (thisex
!= NULL
&& thisex
->present
== 1)) {
424 SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS
, SSL_R_BAD_EXTENSION
);
425 *al
= SSL_AD_ILLEGAL_PARAMETER
;
428 if (thisex
!= NULL
) {
429 thisex
->data
= extension
;
436 * Initialise all known extensions relevant to this context, whether we have
439 for (thisexd
= ext_defs
, i
= 0; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
440 if(thisexd
->init
!= NULL
&& (thisexd
->context
& context
) != 0
441 && extension_is_relevant(s
, thisexd
->context
, context
)
442 && !thisexd
->init(s
, context
)) {
443 *al
= SSL_AD_INTERNAL_ERROR
;
448 *res
= raw_extensions
;
452 OPENSSL_free(raw_extensions
);
457 * Runs the parser for a given extension with index |idx|. |exts| contains the
458 * list of all parsed extensions previously collected by
459 * tls_collect_extensions(). The parser is only run if it is applicable for the
460 * given |context| and the parser has not already been run. If this is for a
461 * Certificate message, then we also provide the parser with the relevant
462 * Certificate |x| and its position in the |chainidx| with 0 being the first
463 * Certificate. Returns 1 on success or 0 on failure. In the event of a failure
464 * |*al| is populated with a suitable alert code. If an extension is not present
465 * this counted as success.
467 int tls_parse_extension(SSL
*s
, TLSEXT_INDEX idx
, int context
,
468 RAW_EXTENSION
*exts
, X509
*x
, size_t chainidx
, int *al
)
470 RAW_EXTENSION
*currext
= &exts
[idx
];
471 int (*parser
)(SSL
*s
, PACKET
*pkt
, X509
*x
, size_t chainidx
, int *al
) = NULL
;
473 /* Skip if the extension is not present */
474 if (!currext
->present
)
478 s
->ext
.debug_cb(s
, !s
->server
, currext
->type
,
479 PACKET_data(&currext
->data
),
480 PACKET_remaining(&currext
->data
),
483 /* Skip if we've already parsed this extension */
489 if (idx
< OSSL_NELEM(ext_defs
)) {
490 /* We are handling a built-in extension */
491 const EXTENSION_DEFINITION
*extdef
= &ext_defs
[idx
];
493 /* Check if extension is defined for our protocol. If not, skip */
494 if (!extension_is_relevant(s
, extdef
->context
, context
))
497 parser
= s
->server
? extdef
->parse_ctos
: extdef
->parse_stoc
;
500 return parser(s
, &currext
->data
, x
, chainidx
, al
);
503 * If the parser is NULL we fall through to the custom extension
509 * This is a custom extension. We only allow this if it is a non
510 * resumed session on the server side.
512 * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions.
513 * We're going to need a new mechanism for TLS1.3 to specify which
514 * messages to add the custom extensions to.
516 if ((!s
->hit
|| !s
->server
)
518 & (EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
)) != 0
519 && custom_ext_parse(s
, s
->server
, currext
->type
,
520 PACKET_data(&currext
->data
),
521 PACKET_remaining(&currext
->data
),
529 * Parse all remaining extensions that have not yet been parsed. Also calls the
530 * finalisation for all extensions at the end, whether we collected them or not.
531 * Returns 1 for success or 0 for failure. If we are working on a Certificate
532 * message then we also pass the Certificate |x| and its position in the
533 * |chainidx|, with 0 being the first certificate. On failure, |*al| is
534 * populated with a suitable alert code.
536 int tls_parse_all_extensions(SSL
*s
, int context
, RAW_EXTENSION
*exts
, X509
*x
,
537 size_t chainidx
, int *al
)
539 size_t i
, numexts
= OSSL_NELEM(ext_defs
);
540 const EXTENSION_DEFINITION
*thisexd
;
542 /* Calculate the number of extensions in the extensions list */
543 if ((context
& EXT_CLIENT_HELLO
) != 0) {
544 numexts
+= s
->cert
->srv_ext
.meths_count
;
545 } else if ((context
& EXT_TLS1_2_SERVER_HELLO
) != 0) {
546 numexts
+= s
->cert
->cli_ext
.meths_count
;
549 /* Parse each extension in turn */
550 for (i
= 0; i
< numexts
; i
++) {
551 if (!tls_parse_extension(s
, i
, context
, exts
, x
, chainidx
, al
))
556 * Finalise all known extensions relevant to this context, whether we have
559 for (i
= 0, thisexd
= ext_defs
; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
560 if(thisexd
->final
!= NULL
561 && (thisexd
->context
& context
) != 0
562 && !thisexd
->final(s
, context
, exts
[i
].present
, al
))
570 * Construct all the extensions relevant to the current |context| and write
571 * them to |pkt|. If this is an extension for a Certificate in a Certificate
572 * message, then |x| will be set to the Certificate we are handling, and
573 * |chainidx| will indicate the position in the chainidx we are processing (with
574 * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a
575 * failure occurs then |al| is populated with a suitable alert code. On a
576 * failure construction stops at the first extension to fail to construct.
578 int tls_construct_extensions(SSL
*s
, WPACKET
*pkt
, unsigned int context
,
579 X509
*x
, size_t chainidx
, int *al
)
582 int addcustom
= 0, min_version
, max_version
= 0, reason
, tmpal
;
583 const EXTENSION_DEFINITION
*thisexd
;
586 * Normally if something goes wrong during construction it's an internal
587 * error. We can always override this later.
589 tmpal
= SSL_AD_INTERNAL_ERROR
;
591 if (!WPACKET_start_sub_packet_u16(pkt
)
593 * If extensions are of zero length then we don't even add the
594 * extensions length bytes to a ClientHello/ServerHello in SSLv3
596 || ((context
& (EXT_CLIENT_HELLO
| EXT_TLS1_2_SERVER_HELLO
)) != 0
597 && s
->version
== SSL3_VERSION
598 && !WPACKET_set_flags(pkt
,
599 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH
))) {
600 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, ERR_R_INTERNAL_ERROR
);
604 if ((context
& EXT_CLIENT_HELLO
) != 0) {
605 reason
= ssl_get_client_min_max_version(s
, &min_version
, &max_version
);
607 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, reason
);
612 /* Add custom extensions first */
613 if ((context
& EXT_CLIENT_HELLO
) != 0) {
614 custom_ext_init(&s
->cert
->cli_ext
);
616 } else if ((context
& EXT_TLS1_2_SERVER_HELLO
) != 0) {
618 * We already initialised the custom extensions during ClientHello
621 * TODO(TLS1.3): We're going to need a new custom extension mechanism
622 * for TLS1.3, so that custom extensions can specify which of the
623 * multiple message they wish to add themselves to.
628 if (addcustom
&& !custom_ext_add(s
, s
->server
, pkt
, &tmpal
)) {
629 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, ERR_R_INTERNAL_ERROR
);
633 for (i
= 0, thisexd
= ext_defs
; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
634 int (*construct
)(SSL
*s
, WPACKET
*pkt
, X509
*x
, size_t chainidx
,
637 /* Skip if not relevant for our context */
638 if ((thisexd
->context
& context
) == 0)
641 construct
= s
->server
? thisexd
->construct_stoc
642 : thisexd
->construct_ctos
;
644 /* Check if this extension is defined for our protocol. If not, skip */
646 && (thisexd
->context
& EXT_TLS_IMPLEMENTATION_ONLY
)
648 || (s
->version
== SSL3_VERSION
649 && (thisexd
->context
& EXT_SSL3_ALLOWED
) == 0)
651 && (thisexd
->context
& EXT_TLS1_2_AND_BELOW_ONLY
)
654 && (thisexd
->context
& EXT_TLS1_3_ONLY
) != 0
655 && (context
& EXT_CLIENT_HELLO
) == 0)
656 || ((thisexd
->context
& EXT_TLS1_3_ONLY
) != 0
657 && (context
& EXT_CLIENT_HELLO
) != 0
658 && (SSL_IS_DTLS(s
) || max_version
< TLS1_3_VERSION
))
659 || construct
== NULL
)
662 if (!construct(s
, pkt
, x
, chainidx
, &tmpal
))
666 if (!WPACKET_close(pkt
)) {
667 SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS
, ERR_R_INTERNAL_ERROR
);
679 * Built in extension finalisation and initialisation functions. All initialise
680 * or finalise the associated extension type for the given |context|. For
681 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
682 * otherwise. These functions return 1 on success or 0 on failure. In the event
683 * of a failure then |*al| is populated with a suitable error code.
686 static int final_renegotiate(SSL
*s
, unsigned int context
, int sent
,
691 * Check if we can connect to a server that doesn't support safe
694 if (!(s
->options
& SSL_OP_LEGACY_SERVER_CONNECT
)
695 && !(s
->options
& SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
)
697 *al
= SSL_AD_HANDSHAKE_FAILURE
;
698 SSLerr(SSL_F_FINAL_RENEGOTIATE
,
699 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED
);
706 /* Need RI if renegotiating */
708 && !(s
->options
& SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
)
710 *al
= SSL_AD_HANDSHAKE_FAILURE
;
711 SSLerr(SSL_F_FINAL_RENEGOTIATE
,
712 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED
);
720 static int init_server_name(SSL
*s
, unsigned int context
)
723 s
->servername_done
= 0;
728 static int final_server_name(SSL
*s
, unsigned int context
, int sent
,
731 int ret
= SSL_TLSEXT_ERR_NOACK
;
732 int altmp
= SSL_AD_UNRECOGNIZED_NAME
;
734 if (s
->ctx
!= NULL
&& s
->ctx
->ext
.servername_cb
!= 0)
735 ret
= s
->ctx
->ext
.servername_cb(s
, &altmp
,
736 s
->ctx
->ext
.servername_arg
);
737 else if (s
->initial_ctx
!= NULL
738 && s
->initial_ctx
->ext
.servername_cb
!= 0)
739 ret
= s
->initial_ctx
->ext
.servername_cb(s
, &altmp
,
740 s
->initial_ctx
->ext
.servername_arg
);
743 case SSL_TLSEXT_ERR_ALERT_FATAL
:
747 case SSL_TLSEXT_ERR_ALERT_WARNING
:
751 case SSL_TLSEXT_ERR_NOACK
:
752 s
->servername_done
= 0;
760 #ifndef OPENSSL_NO_EC
761 static int final_ec_pt_formats(SSL
*s
, unsigned int context
, int sent
,
764 unsigned long alg_k
, alg_a
;
769 alg_k
= s
->s3
->tmp
.new_cipher
->algorithm_mkey
;
770 alg_a
= s
->s3
->tmp
.new_cipher
->algorithm_auth
;
773 * If we are client and using an elliptic curve cryptography cipher
774 * suite, then if server returns an EC point formats lists extension it
775 * must contain uncompressed.
777 if (s
->ext
.ecpointformats
!= NULL
778 && s
->ext
.ecpointformats_len
> 0
779 && s
->session
->ext
.ecpointformats
!= NULL
780 && s
->session
->ext
.ecpointformats_len
> 0
781 && ((alg_k
& SSL_kECDHE
) || (alg_a
& SSL_aECDSA
))) {
782 /* we are using an ECC cipher */
784 unsigned char *list
= s
->session
->ext
.ecpointformats
;
786 for (i
= 0; i
< s
->session
->ext
.ecpointformats_len
; i
++) {
787 if (*list
++ == TLSEXT_ECPOINTFORMAT_uncompressed
)
790 if (i
== s
->session
->ext
.ecpointformats_len
) {
791 SSLerr(SSL_F_FINAL_EC_PT_FORMATS
,
792 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST
);
801 static int init_session_ticket(SSL
*s
, unsigned int context
)
804 s
->ext
.ticket_expected
= 0;
809 #ifndef OPENSSL_NO_OCSP
810 static int init_status_request(SSL
*s
, unsigned int context
)
813 s
->ext
.status_type
= TLSEXT_STATUSTYPE_nothing
;
816 * Ensure we get sensible values passed to tlsext_status_cb in the event
817 * that we don't receive a status message
819 OPENSSL_free(s
->ext
.ocsp
.resp
);
820 s
->ext
.ocsp
.resp
= NULL
;
821 s
->ext
.ocsp
.resp_len
= 0;
828 #ifndef OPENSSL_NO_NEXTPROTONEG
829 static int init_npn(SSL
*s
, unsigned int context
)
837 static int init_alpn(SSL
*s
, unsigned int context
)
839 OPENSSL_free(s
->s3
->alpn_selected
);
840 s
->s3
->alpn_selected
= NULL
;
842 s
->s3
->alpn_selected_len
= 0;
843 OPENSSL_free(s
->s3
->alpn_proposed
);
844 s
->s3
->alpn_proposed
= NULL
;
845 s
->s3
->alpn_proposed_len
= 0;
850 static int final_alpn(SSL
*s
, unsigned int context
, int sent
, int *al
)
852 const unsigned char *selected
= NULL
;
853 unsigned char selected_len
= 0;
858 if (s
->ctx
->ext
.alpn_select_cb
!= NULL
&& s
->s3
->alpn_proposed
!= NULL
) {
859 int r
= s
->ctx
->ext
.alpn_select_cb(s
, &selected
, &selected_len
,
860 s
->s3
->alpn_proposed
,
861 (unsigned int)s
->s3
->alpn_proposed_len
,
862 s
->ctx
->ext
.alpn_select_cb_arg
);
864 if (r
== SSL_TLSEXT_ERR_OK
) {
865 OPENSSL_free(s
->s3
->alpn_selected
);
866 s
->s3
->alpn_selected
= OPENSSL_memdup(selected
, selected_len
);
867 if (s
->s3
->alpn_selected
== NULL
) {
868 *al
= SSL_AD_INTERNAL_ERROR
;
871 s
->s3
->alpn_selected_len
= selected_len
;
872 #ifndef OPENSSL_NO_NEXTPROTONEG
873 /* ALPN takes precedence over NPN. */
877 *al
= SSL_AD_NO_APPLICATION_PROTOCOL
;
885 static int init_sig_algs(SSL
*s
, unsigned int context
)
887 /* Clear any signature algorithms extension received */
888 OPENSSL_free(s
->s3
->tmp
.peer_sigalgs
);
889 s
->s3
->tmp
.peer_sigalgs
= NULL
;
894 #ifndef OPENSSL_NO_SRP
895 static int init_srp(SSL
*s
, unsigned int context
)
897 OPENSSL_free(s
->srp_ctx
.login
);
898 s
->srp_ctx
.login
= NULL
;
904 static int init_etm(SSL
*s
, unsigned int context
)
906 s
->s3
->flags
&= ~TLS1_FLAGS_ENCRYPT_THEN_MAC
;
911 static int init_ems(SSL
*s
, unsigned int context
)
914 s
->s3
->flags
&= ~TLS1_FLAGS_RECEIVED_EXTMS
;
919 static int final_ems(SSL
*s
, unsigned int context
, int sent
, int *al
)
921 if (!s
->server
&& s
->hit
) {
923 * Check extended master secret extension is consistent with
926 if (!(s
->s3
->flags
& TLS1_FLAGS_RECEIVED_EXTMS
) !=
927 !(s
->session
->flags
& SSL_SESS_FLAG_EXTMS
)) {
928 *al
= SSL_AD_HANDSHAKE_FAILURE
;
929 SSLerr(SSL_F_FINAL_EMS
, SSL_R_INCONSISTENT_EXTMS
);
937 #ifndef OPENSSL_NO_SRTP
938 static int init_srtp(SSL
*s
, unsigned int context
)
941 s
->srtp_profile
= NULL
;
947 static int final_sig_algs(SSL
*s
, unsigned int context
, int sent
, int *al
)
949 if (!sent
&& SSL_IS_TLS13(s
)) {
950 *al
= TLS13_AD_MISSING_EXTENSION
;
951 SSLerr(SSL_F_FINAL_SIG_ALGS
, SSL_R_MISSING_SIGALGS_EXTENSION
);
958 static int init_psk_kex_modes(SSL
*s
, unsigned int context
)
960 s
->ext
.psk_kex_mode
= TLSEXT_KEX_MODE_FLAG_NONE
;