2 * Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include "internal/nelem.h"
12 #include "internal/cryptlib.h"
13 #include "../ssl_local.h"
14 #include "statem_local.h"
15 #include "internal/cryptlib.h"
17 static int final_renegotiate(SSL
*s
, unsigned int context
, int sent
);
18 static int init_server_name(SSL
*s
, unsigned int context
);
19 static int final_server_name(SSL
*s
, unsigned int context
, int sent
);
21 static int final_ec_pt_formats(SSL
*s
, unsigned int context
, int sent
);
23 static int init_session_ticket(SSL
*s
, unsigned int context
);
24 #ifndef OPENSSL_NO_OCSP
25 static int init_status_request(SSL
*s
, unsigned int context
);
27 #ifndef OPENSSL_NO_NEXTPROTONEG
28 static int init_npn(SSL
*s
, unsigned int context
);
30 static int init_alpn(SSL
*s
, unsigned int context
);
31 static int final_alpn(SSL
*s
, unsigned int context
, int sent
);
32 static int init_sig_algs_cert(SSL
*s
, unsigned int context
);
33 static int init_sig_algs(SSL
*s
, unsigned int context
);
34 static int init_certificate_authorities(SSL
*s
, unsigned int context
);
35 static EXT_RETURN
tls_construct_certificate_authorities(SSL
*s
, WPACKET
*pkt
,
39 static int tls_parse_certificate_authorities(SSL
*s
, PACKET
*pkt
,
40 unsigned int context
, X509
*x
,
42 #ifndef OPENSSL_NO_SRP
43 static int init_srp(SSL
*s
, unsigned int context
);
45 static int init_etm(SSL
*s
, unsigned int context
);
46 static int init_ems(SSL
*s
, unsigned int context
);
47 static int final_ems(SSL
*s
, unsigned int context
, int sent
);
48 static int init_psk_kex_modes(SSL
*s
, unsigned int context
);
49 static int final_key_share(SSL
*s
, unsigned int context
, int sent
);
50 #ifndef OPENSSL_NO_SRTP
51 static int init_srtp(SSL
*s
, unsigned int context
);
53 static int final_sig_algs(SSL
*s
, unsigned int context
, int sent
);
54 static int final_early_data(SSL
*s
, unsigned int context
, int sent
);
55 static int final_maxfragmentlen(SSL
*s
, unsigned int context
, int sent
);
56 static int init_post_handshake_auth(SSL
*s
, unsigned int context
);
58 /* Structure to define a built-in extension */
59 typedef struct extensions_definition_st
{
60 /* The defined type for the extension */
63 * The context that this extension applies to, e.g. what messages and
68 * Initialise extension before parsing. Always called for relevant contexts
69 * even if extension not present
71 int (*init
)(SSL
*s
, unsigned int context
);
72 /* Parse extension sent from client to server */
73 int (*parse_ctos
)(SSL
*s
, PACKET
*pkt
, unsigned int context
, X509
*x
,
75 /* Parse extension send from server to client */
76 int (*parse_stoc
)(SSL
*s
, PACKET
*pkt
, unsigned int context
, X509
*x
,
78 /* Construct extension sent from server to client */
79 EXT_RETURN (*construct_stoc
)(SSL
*s
, WPACKET
*pkt
, unsigned int context
,
80 X509
*x
, size_t chainidx
);
81 /* Construct extension sent from client to server */
82 EXT_RETURN (*construct_ctos
)(SSL
*s
, WPACKET
*pkt
, unsigned int context
,
83 X509
*x
, size_t chainidx
);
85 * Finalise extension after parsing. Always called where an extensions was
86 * initialised even if the extension was not present. |sent| is set to 1 if
87 * the extension was seen, or 0 otherwise.
89 int (*final
)(SSL
*s
, unsigned int context
, int sent
);
90 } EXTENSION_DEFINITION
;
93 * Definitions of all built-in extensions. NOTE: Changes in the number or order
94 * of these extensions should be mirrored with equivalent changes to the
95 * indexes ( TLSEXT_IDX_* ) defined in ssl_local.h.
96 * Each extension has an initialiser, a client and
97 * server side parser and a finaliser. The initialiser is called (if the
98 * extension is relevant to the given context) even if we did not see the
99 * extension in the message that we received. The parser functions are only
100 * called if we see the extension in the message. The finalisers are always
101 * called if the initialiser was called.
102 * There are also server and client side constructor functions which are always
103 * called during message construction if the extension is relevant for the
105 * The initialisation, parsing, finalisation and construction functions are
106 * always called in the order defined in this list. Some extensions may depend
107 * on others having been processed first, so the order of this list is
109 * The extension context is defined by a series of flags which specify which
110 * messages the extension is relevant to. These flags also specify whether the
111 * extension is relevant to a particular protocol or protocol version.
113 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
115 * NOTE: WebSphere Application Server 7+ cannot handle empty extensions at
116 * the end, keep these extensions before signature_algorithm.
118 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
119 static const EXTENSION_DEFINITION ext_defs
[] = {
121 TLSEXT_TYPE_renegotiate
,
122 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
123 | SSL_EXT_SSL3_ALLOWED
| SSL_EXT_TLS1_2_AND_BELOW_ONLY
,
124 NULL
, tls_parse_ctos_renegotiate
, tls_parse_stoc_renegotiate
,
125 tls_construct_stoc_renegotiate
, tls_construct_ctos_renegotiate
,
129 TLSEXT_TYPE_server_name
,
130 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
131 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
133 tls_parse_ctos_server_name
, tls_parse_stoc_server_name
,
134 tls_construct_stoc_server_name
, tls_construct_ctos_server_name
,
138 TLSEXT_TYPE_max_fragment_length
,
139 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
140 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
141 NULL
, tls_parse_ctos_maxfragmentlen
, tls_parse_stoc_maxfragmentlen
,
142 tls_construct_stoc_maxfragmentlen
, tls_construct_ctos_maxfragmentlen
,
145 #ifndef OPENSSL_NO_SRP
148 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_AND_BELOW_ONLY
,
149 init_srp
, tls_parse_ctos_srp
, NULL
, NULL
, tls_construct_ctos_srp
, NULL
154 #ifndef OPENSSL_NO_EC
156 TLSEXT_TYPE_ec_point_formats
,
157 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
158 | SSL_EXT_TLS1_2_AND_BELOW_ONLY
,
159 NULL
, tls_parse_ctos_ec_pt_formats
, tls_parse_stoc_ec_pt_formats
,
160 tls_construct_stoc_ec_pt_formats
, tls_construct_ctos_ec_pt_formats
,
166 #if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
169 * "supported_groups" is spread across several specifications.
170 * It was originally specified as "elliptic_curves" in RFC 4492,
171 * and broadened to include named FFDH groups by RFC 7919.
172 * Both RFCs 4492 and 7919 do not include a provision for the server
173 * to indicate to the client the complete list of groups supported
174 * by the server, with the server instead just indicating the
175 * selected group for this connection in the ServerKeyExchange
176 * message. TLS 1.3 adds a scheme for the server to indicate
177 * to the client its list of supported groups in the
178 * EncryptedExtensions message, but none of the relevant
179 * specifications permit sending supported_groups in the ServerHello.
180 * Nonetheless (possibly due to the close proximity to the
181 * "ec_point_formats" extension, which is allowed in the ServerHello),
182 * there are several servers that send this extension in the
183 * ServerHello anyway. Up to and including the 1.1.0 release,
184 * we did not check for the presence of nonpermitted extensions,
185 * so to avoid a regression, we must permit this extension in the
186 * TLS 1.2 ServerHello as well.
188 * Note that there is no tls_parse_stoc_supported_groups function,
189 * so we do not perform any additional parsing, validation, or
190 * processing on the server's group list -- this is just a minimal
191 * change to preserve compatibility with these misbehaving servers.
193 TLSEXT_TYPE_supported_groups
,
194 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
195 | SSL_EXT_TLS1_2_SERVER_HELLO
,
196 NULL
, tls_parse_ctos_supported_groups
, NULL
,
197 tls_construct_stoc_supported_groups
,
198 tls_construct_ctos_supported_groups
, NULL
204 TLSEXT_TYPE_session_ticket
,
205 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
206 | SSL_EXT_TLS1_2_AND_BELOW_ONLY
,
207 init_session_ticket
, tls_parse_ctos_session_ticket
,
208 tls_parse_stoc_session_ticket
, tls_construct_stoc_session_ticket
,
209 tls_construct_ctos_session_ticket
, NULL
211 #ifndef OPENSSL_NO_OCSP
213 TLSEXT_TYPE_status_request
,
214 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
215 | SSL_EXT_TLS1_3_CERTIFICATE
| SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
,
216 init_status_request
, tls_parse_ctos_status_request
,
217 tls_parse_stoc_status_request
, tls_construct_stoc_status_request
,
218 tls_construct_ctos_status_request
, NULL
223 #ifndef OPENSSL_NO_NEXTPROTONEG
225 TLSEXT_TYPE_next_proto_neg
,
226 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
227 | SSL_EXT_TLS1_2_AND_BELOW_ONLY
,
228 init_npn
, tls_parse_ctos_npn
, tls_parse_stoc_npn
,
229 tls_construct_stoc_next_proto_neg
, tls_construct_ctos_npn
, NULL
236 * Must appear in this list after server_name so that finalisation
237 * happens after server_name callbacks
239 TLSEXT_TYPE_application_layer_protocol_negotiation
,
240 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
241 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
,
242 init_alpn
, tls_parse_ctos_alpn
, tls_parse_stoc_alpn
,
243 tls_construct_stoc_alpn
, tls_construct_ctos_alpn
, final_alpn
245 #ifndef OPENSSL_NO_SRTP
247 TLSEXT_TYPE_use_srtp
,
248 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
249 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
| SSL_EXT_DTLS_ONLY
,
250 init_srtp
, tls_parse_ctos_use_srtp
, tls_parse_stoc_use_srtp
,
251 tls_construct_stoc_use_srtp
, tls_construct_ctos_use_srtp
, NULL
257 TLSEXT_TYPE_encrypt_then_mac
,
258 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
259 | SSL_EXT_TLS1_2_AND_BELOW_ONLY
,
260 init_etm
, tls_parse_ctos_etm
, tls_parse_stoc_etm
,
261 tls_construct_stoc_etm
, tls_construct_ctos_etm
, NULL
263 #ifndef OPENSSL_NO_CT
265 TLSEXT_TYPE_signed_certificate_timestamp
,
266 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
267 | SSL_EXT_TLS1_3_CERTIFICATE
| SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
,
270 * No server side support for this, but can be provided by a custom
271 * extension. This is an exception to the rule that custom extensions
272 * cannot override built in ones.
274 NULL
, tls_parse_stoc_sct
, NULL
, tls_construct_ctos_sct
, NULL
280 TLSEXT_TYPE_extended_master_secret
,
281 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
282 | SSL_EXT_TLS1_2_AND_BELOW_ONLY
,
283 init_ems
, tls_parse_ctos_ems
, tls_parse_stoc_ems
,
284 tls_construct_stoc_ems
, tls_construct_ctos_ems
, final_ems
287 TLSEXT_TYPE_signature_algorithms_cert
,
288 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
,
289 init_sig_algs_cert
, tls_parse_ctos_sig_algs_cert
,
290 tls_parse_ctos_sig_algs_cert
,
291 /* We do not generate signature_algorithms_cert at present. */
295 TLSEXT_TYPE_post_handshake_auth
,
296 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_ONLY
,
297 init_post_handshake_auth
,
298 tls_parse_ctos_post_handshake_auth
, NULL
,
299 NULL
, tls_construct_ctos_post_handshake_auth
,
303 TLSEXT_TYPE_signature_algorithms
,
304 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
,
305 init_sig_algs
, tls_parse_ctos_sig_algs
,
306 tls_parse_ctos_sig_algs
, tls_construct_ctos_sig_algs
,
307 tls_construct_ctos_sig_algs
, final_sig_algs
310 TLSEXT_TYPE_supported_versions
,
311 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_SERVER_HELLO
312 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
| SSL_EXT_TLS_IMPLEMENTATION_ONLY
,
314 /* Processed inline as part of version selection */
315 NULL
, tls_parse_stoc_supported_versions
,
316 tls_construct_stoc_supported_versions
,
317 tls_construct_ctos_supported_versions
, NULL
320 TLSEXT_TYPE_psk_kex_modes
,
321 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS_IMPLEMENTATION_ONLY
322 | SSL_EXT_TLS1_3_ONLY
,
323 init_psk_kex_modes
, tls_parse_ctos_psk_kex_modes
, NULL
, NULL
,
324 tls_construct_ctos_psk_kex_modes
, NULL
328 * Must be in this list after supported_groups. We need that to have
329 * been parsed before we do this one.
331 TLSEXT_TYPE_key_share
,
332 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_SERVER_HELLO
333 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
| SSL_EXT_TLS_IMPLEMENTATION_ONLY
334 | SSL_EXT_TLS1_3_ONLY
,
335 NULL
, tls_parse_ctos_key_share
, tls_parse_stoc_key_share
,
336 tls_construct_stoc_key_share
, tls_construct_ctos_key_share
,
340 /* Must be after key_share */
342 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
343 | SSL_EXT_TLS_IMPLEMENTATION_ONLY
| SSL_EXT_TLS1_3_ONLY
,
344 NULL
, tls_parse_ctos_cookie
, tls_parse_stoc_cookie
,
345 tls_construct_stoc_cookie
, tls_construct_ctos_cookie
, NULL
349 * Special unsolicited ServerHello extension only used when
350 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set. We allow it in a ClientHello but
353 TLSEXT_TYPE_cryptopro_bug
,
354 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
355 | SSL_EXT_TLS1_2_AND_BELOW_ONLY
,
356 NULL
, NULL
, NULL
, tls_construct_stoc_cryptopro_bug
, NULL
, NULL
359 TLSEXT_TYPE_early_data
,
360 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
361 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET
| SSL_EXT_TLS1_3_ONLY
,
362 NULL
, tls_parse_ctos_early_data
, tls_parse_stoc_early_data
,
363 tls_construct_stoc_early_data
, tls_construct_ctos_early_data
,
367 TLSEXT_TYPE_certificate_authorities
,
368 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
369 | SSL_EXT_TLS1_3_ONLY
,
370 init_certificate_authorities
,
371 tls_parse_certificate_authorities
, tls_parse_certificate_authorities
,
372 tls_construct_certificate_authorities
,
373 tls_construct_certificate_authorities
, NULL
,
376 /* Must be immediately before pre_shared_key */
378 SSL_EXT_CLIENT_HELLO
,
380 /* We send this, but don't read it */
381 NULL
, NULL
, NULL
, tls_construct_ctos_padding
, NULL
384 /* Required by the TLSv1.3 spec to always be the last extension */
386 SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_3_SERVER_HELLO
387 | SSL_EXT_TLS_IMPLEMENTATION_ONLY
| SSL_EXT_TLS1_3_ONLY
,
388 NULL
, tls_parse_ctos_psk
, tls_parse_stoc_psk
, tls_construct_stoc_psk
,
389 tls_construct_ctos_psk
, NULL
393 /* Check whether an extension's context matches the current context */
394 static int validate_context(SSL
*s
, unsigned int extctx
, unsigned int thisctx
)
396 /* Check we're allowed to use this extension in this context */
397 if ((thisctx
& extctx
) == 0)
400 if (SSL_IS_DTLS(s
)) {
401 if ((extctx
& SSL_EXT_TLS_ONLY
) != 0)
403 } else if ((extctx
& SSL_EXT_DTLS_ONLY
) != 0) {
410 int tls_validate_all_contexts(SSL
*s
, unsigned int thisctx
, RAW_EXTENSION
*exts
)
412 size_t i
, num_exts
, builtin_num
= OSSL_NELEM(ext_defs
), offset
;
413 RAW_EXTENSION
*thisext
;
414 unsigned int context
;
415 ENDPOINT role
= ENDPOINT_BOTH
;
417 if ((thisctx
& SSL_EXT_CLIENT_HELLO
) != 0)
418 role
= ENDPOINT_SERVER
;
419 else if ((thisctx
& SSL_EXT_TLS1_2_SERVER_HELLO
) != 0)
420 role
= ENDPOINT_CLIENT
;
422 /* Calculate the number of extensions in the extensions list */
423 num_exts
= builtin_num
+ s
->cert
->custext
.meths_count
;
425 for (thisext
= exts
, i
= 0; i
< num_exts
; i
++, thisext
++) {
426 if (!thisext
->present
)
429 if (i
< builtin_num
) {
430 context
= ext_defs
[i
].context
;
432 custom_ext_method
*meth
= NULL
;
434 meth
= custom_ext_find(&s
->cert
->custext
, role
, thisext
->type
,
436 if (!ossl_assert(meth
!= NULL
))
438 context
= meth
->context
;
441 if (!validate_context(s
, context
, thisctx
))
449 * Verify whether we are allowed to use the extension |type| in the current
450 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
451 * indicate the extension is not allowed. If returning 1 then |*found| is set to
452 * the definition for the extension we found.
454 static int verify_extension(SSL
*s
, unsigned int context
, unsigned int type
,
455 custom_ext_methods
*meths
, RAW_EXTENSION
*rawexlist
,
456 RAW_EXTENSION
**found
)
459 size_t builtin_num
= OSSL_NELEM(ext_defs
);
460 const EXTENSION_DEFINITION
*thisext
;
462 for (i
= 0, thisext
= ext_defs
; i
< builtin_num
; i
++, thisext
++) {
463 if (type
== thisext
->type
) {
464 if (!validate_context(s
, thisext
->context
, context
))
467 *found
= &rawexlist
[i
];
472 /* Check the custom extensions */
475 ENDPOINT role
= ENDPOINT_BOTH
;
476 custom_ext_method
*meth
= NULL
;
478 if ((context
& SSL_EXT_CLIENT_HELLO
) != 0)
479 role
= ENDPOINT_SERVER
;
480 else if ((context
& SSL_EXT_TLS1_2_SERVER_HELLO
) != 0)
481 role
= ENDPOINT_CLIENT
;
483 meth
= custom_ext_find(meths
, role
, type
, &offset
);
485 if (!validate_context(s
, meth
->context
, context
))
487 *found
= &rawexlist
[offset
+ builtin_num
];
492 /* Unknown extension. We allow it */
498 * Check whether the context defined for an extension |extctx| means whether
499 * the extension is relevant for the current context |thisctx| or not. Returns
500 * 1 if the extension is relevant for this context, and 0 otherwise
502 int extension_is_relevant(SSL
*s
, unsigned int extctx
, unsigned int thisctx
)
507 * For HRR we haven't selected the version yet but we know it will be
510 if ((thisctx
& SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
) != 0)
513 is_tls13
= SSL_IS_TLS13(s
);
516 && (extctx
& SSL_EXT_TLS_IMPLEMENTATION_ONLY
) != 0)
517 || (s
->version
== SSL3_VERSION
518 && (extctx
& SSL_EXT_SSL3_ALLOWED
) == 0)
520 * Note that SSL_IS_TLS13() means "TLS 1.3 has been negotiated",
521 * which is never true when generating the ClientHello.
522 * However, version negotiation *has* occurred by the time the
523 * ClientHello extensions are being parsed.
524 * Be careful to allow TLS 1.3-only extensions when generating
527 || (is_tls13
&& (extctx
& SSL_EXT_TLS1_2_AND_BELOW_ONLY
) != 0)
528 || (!is_tls13
&& (extctx
& SSL_EXT_TLS1_3_ONLY
) != 0
529 && (thisctx
& SSL_EXT_CLIENT_HELLO
) == 0)
530 || (s
->server
&& !is_tls13
&& (extctx
& SSL_EXT_TLS1_3_ONLY
) != 0)
531 || (s
->hit
&& (extctx
& SSL_EXT_IGNORE_ON_RESUMPTION
) != 0))
537 * Gather a list of all the extensions from the data in |packet]. |context|
538 * tells us which message this extension is for. The raw extension data is
539 * stored in |*res| on success. We don't actually process the content of the
540 * extensions yet, except to check their types. This function also runs the
541 * initialiser functions for all known extensions if |init| is nonzero (whether
542 * we have collected them or not). If successful the caller is responsible for
543 * freeing the contents of |*res|.
545 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
546 * more than one extension of the same type in a ClientHello or ServerHello.
547 * This function returns 1 if all extensions are unique and we have parsed their
548 * types, and 0 if the extensions contain duplicates, could not be successfully
549 * found, or an internal error occurred. We only check duplicates for
550 * extensions that we know about. We ignore others.
552 int tls_collect_extensions(SSL
*s
, PACKET
*packet
, unsigned int context
,
553 RAW_EXTENSION
**res
, size_t *len
, int init
)
555 PACKET extensions
= *packet
;
558 custom_ext_methods
*exts
= &s
->cert
->custext
;
559 RAW_EXTENSION
*raw_extensions
= NULL
;
560 const EXTENSION_DEFINITION
*thisexd
;
565 * Initialise server side custom extensions. Client side is done during
566 * construction of extensions for the ClientHello.
568 if ((context
& SSL_EXT_CLIENT_HELLO
) != 0)
569 custom_ext_init(&s
->cert
->custext
);
571 num_exts
= OSSL_NELEM(ext_defs
) + (exts
!= NULL
? exts
->meths_count
: 0);
572 raw_extensions
= OPENSSL_zalloc(num_exts
* sizeof(*raw_extensions
));
573 if (raw_extensions
== NULL
) {
574 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_MALLOC_FAILURE
);
579 while (PACKET_remaining(&extensions
) > 0) {
580 unsigned int type
, idx
;
582 RAW_EXTENSION
*thisex
;
584 if (!PACKET_get_net_2(&extensions
, &type
) ||
585 !PACKET_get_length_prefixed_2(&extensions
, &extension
)) {
586 SSLfatal(s
, SSL_AD_DECODE_ERROR
, SSL_R_BAD_EXTENSION
);
590 * Verify this extension is allowed. We only check duplicates for
591 * extensions that we recognise. We also have a special case for the
592 * PSK extension, which must be the last one in the ClientHello.
594 if (!verify_extension(s
, context
, type
, exts
, raw_extensions
, &thisex
)
595 || (thisex
!= NULL
&& thisex
->present
== 1)
596 || (type
== TLSEXT_TYPE_psk
597 && (context
& SSL_EXT_CLIENT_HELLO
) != 0
598 && PACKET_remaining(&extensions
) != 0)) {
599 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_BAD_EXTENSION
);
602 idx
= thisex
- raw_extensions
;
604 * Check that we requested this extension (if appropriate). Requests can
605 * be sent in the ClientHello and CertificateRequest. Unsolicited
606 * extensions can be sent in the NewSessionTicket. We only do this for
607 * the built-in extensions. Custom extensions have a different but
608 * similar check elsewhere.
610 * - The HRR cookie extension is unsolicited
611 * - The renegotiate extension is unsolicited (the client signals
612 * support via an SCSV)
613 * - The signed_certificate_timestamp extension can be provided by a
614 * custom extension or by the built-in version. We let the extension
615 * itself handle unsolicited response checks.
617 if (idx
< OSSL_NELEM(ext_defs
)
618 && (context
& (SSL_EXT_CLIENT_HELLO
619 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
620 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET
)) == 0
621 && type
!= TLSEXT_TYPE_cookie
622 && type
!= TLSEXT_TYPE_renegotiate
623 && type
!= TLSEXT_TYPE_signed_certificate_timestamp
624 && (s
->ext
.extflags
[idx
] & SSL_EXT_FLAG_SENT
) == 0
625 #ifndef OPENSSL_NO_GOST
626 && !((context
& SSL_EXT_TLS1_2_SERVER_HELLO
) != 0
627 && type
== TLSEXT_TYPE_cryptopro_bug
)
630 SSLfatal(s
, SSL_AD_UNSUPPORTED_EXTENSION
,
631 SSL_R_UNSOLICITED_EXTENSION
);
634 if (thisex
!= NULL
) {
635 thisex
->data
= extension
;
638 thisex
->received_order
= i
++;
640 s
->ext
.debug_cb(s
, !s
->server
, thisex
->type
,
641 PACKET_data(&thisex
->data
),
642 PACKET_remaining(&thisex
->data
),
649 * Initialise all known extensions relevant to this context,
650 * whether we have found them or not
652 for (thisexd
= ext_defs
, i
= 0; i
< OSSL_NELEM(ext_defs
);
654 if (thisexd
->init
!= NULL
&& (thisexd
->context
& context
) != 0
655 && extension_is_relevant(s
, thisexd
->context
, context
)
656 && !thisexd
->init(s
, context
)) {
657 /* SSLfatal() already called */
663 *res
= raw_extensions
;
669 OPENSSL_free(raw_extensions
);
674 * Runs the parser for a given extension with index |idx|. |exts| contains the
675 * list of all parsed extensions previously collected by
676 * tls_collect_extensions(). The parser is only run if it is applicable for the
677 * given |context| and the parser has not already been run. If this is for a
678 * Certificate message, then we also provide the parser with the relevant
679 * Certificate |x| and its position in the |chainidx| with 0 being the first
680 * Certificate. Returns 1 on success or 0 on failure. If an extension is not
681 * present this counted as success.
683 int tls_parse_extension(SSL
*s
, TLSEXT_INDEX idx
, int context
,
684 RAW_EXTENSION
*exts
, X509
*x
, size_t chainidx
)
686 RAW_EXTENSION
*currext
= &exts
[idx
];
687 int (*parser
)(SSL
*s
, PACKET
*pkt
, unsigned int context
, X509
*x
,
688 size_t chainidx
) = NULL
;
690 /* Skip if the extension is not present */
691 if (!currext
->present
)
694 /* Skip if we've already parsed this extension */
700 if (idx
< OSSL_NELEM(ext_defs
)) {
701 /* We are handling a built-in extension */
702 const EXTENSION_DEFINITION
*extdef
= &ext_defs
[idx
];
704 /* Check if extension is defined for our protocol. If not, skip */
705 if (!extension_is_relevant(s
, extdef
->context
, context
))
708 parser
= s
->server
? extdef
->parse_ctos
: extdef
->parse_stoc
;
711 return parser(s
, &currext
->data
, context
, x
, chainidx
);
714 * If the parser is NULL we fall through to the custom extension
719 /* Parse custom extensions */
720 return custom_ext_parse(s
, context
, currext
->type
,
721 PACKET_data(&currext
->data
),
722 PACKET_remaining(&currext
->data
),
727 * Parse all remaining extensions that have not yet been parsed. Also calls the
728 * finalisation for all extensions at the end if |fin| is nonzero, whether we
729 * collected them or not. Returns 1 for success or 0 for failure. If we are
730 * working on a Certificate message then we also pass the Certificate |x| and
731 * its position in the |chainidx|, with 0 being the first certificate.
733 int tls_parse_all_extensions(SSL
*s
, int context
, RAW_EXTENSION
*exts
, X509
*x
,
734 size_t chainidx
, int fin
)
736 size_t i
, numexts
= OSSL_NELEM(ext_defs
);
737 const EXTENSION_DEFINITION
*thisexd
;
739 /* Calculate the number of extensions in the extensions list */
740 numexts
+= s
->cert
->custext
.meths_count
;
742 /* Parse each extension in turn */
743 for (i
= 0; i
< numexts
; i
++) {
744 if (!tls_parse_extension(s
, i
, context
, exts
, x
, chainidx
)) {
745 /* SSLfatal() already called */
752 * Finalise all known extensions relevant to this context,
753 * whether we have found them or not
755 for (i
= 0, thisexd
= ext_defs
; i
< OSSL_NELEM(ext_defs
);
757 if (thisexd
->final
!= NULL
&& (thisexd
->context
& context
) != 0
758 && !thisexd
->final(s
, context
, exts
[i
].present
)) {
759 /* SSLfatal() already called */
768 int should_add_extension(SSL
*s
, unsigned int extctx
, unsigned int thisctx
,
771 /* Skip if not relevant for our context */
772 if ((extctx
& thisctx
) == 0)
775 /* Check if this extension is defined for our protocol. If not, skip */
776 if (!extension_is_relevant(s
, extctx
, thisctx
)
777 || ((extctx
& SSL_EXT_TLS1_3_ONLY
) != 0
778 && (thisctx
& SSL_EXT_CLIENT_HELLO
) != 0
779 && (SSL_IS_DTLS(s
) || max_version
< TLS1_3_VERSION
)))
786 * Construct all the extensions relevant to the current |context| and write
787 * them to |pkt|. If this is an extension for a Certificate in a Certificate
788 * message, then |x| will be set to the Certificate we are handling, and
789 * |chainidx| will indicate the position in the chainidx we are processing (with
790 * 0 being the first in the chain). Returns 1 on success or 0 on failure. On a
791 * failure construction stops at the first extension to fail to construct.
793 int tls_construct_extensions(SSL
*s
, WPACKET
*pkt
, unsigned int context
,
794 X509
*x
, size_t chainidx
)
797 int min_version
, max_version
= 0, reason
;
798 const EXTENSION_DEFINITION
*thisexd
;
800 if (!WPACKET_start_sub_packet_u16(pkt
)
802 * If extensions are of zero length then we don't even add the
803 * extensions length bytes to a ClientHello/ServerHello
807 (SSL_EXT_CLIENT_HELLO
| SSL_EXT_TLS1_2_SERVER_HELLO
)) != 0
808 && !WPACKET_set_flags(pkt
,
809 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH
))) {
810 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
814 if ((context
& SSL_EXT_CLIENT_HELLO
) != 0) {
815 reason
= ssl_get_min_max_version(s
, &min_version
, &max_version
, NULL
);
817 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, reason
);
822 /* Add custom extensions first */
823 if ((context
& SSL_EXT_CLIENT_HELLO
) != 0) {
824 /* On the server side with initialise during ClientHello parsing */
825 custom_ext_init(&s
->cert
->custext
);
827 if (!custom_ext_add(s
, context
, pkt
, x
, chainidx
, max_version
)) {
828 /* SSLfatal() already called */
832 for (i
= 0, thisexd
= ext_defs
; i
< OSSL_NELEM(ext_defs
); i
++, thisexd
++) {
833 EXT_RETURN (*construct
)(SSL
*s
, WPACKET
*pkt
, unsigned int context
,
834 X509
*x
, size_t chainidx
);
837 /* Skip if not relevant for our context */
838 if (!should_add_extension(s
, thisexd
->context
, context
, max_version
))
841 construct
= s
->server
? thisexd
->construct_stoc
842 : thisexd
->construct_ctos
;
844 if (construct
== NULL
)
847 ret
= construct(s
, pkt
, context
, x
, chainidx
);
848 if (ret
== EXT_RETURN_FAIL
) {
849 /* SSLfatal() already called */
852 if (ret
== EXT_RETURN_SENT
853 && (context
& (SSL_EXT_CLIENT_HELLO
854 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
855 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET
)) != 0)
856 s
->ext
.extflags
[i
] |= SSL_EXT_FLAG_SENT
;
859 if (!WPACKET_close(pkt
)) {
860 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
868 * Built in extension finalisation and initialisation functions. All initialise
869 * or finalise the associated extension type for the given |context|. For
870 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
871 * otherwise. These functions return 1 on success or 0 on failure.
874 static int final_renegotiate(SSL
*s
, unsigned int context
, int sent
)
878 * Check if we can connect to a server that doesn't support safe
881 if (!(s
->options
& SSL_OP_LEGACY_SERVER_CONNECT
)
882 && !(s
->options
& SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
)
884 SSLfatal(s
, SSL_AD_HANDSHAKE_FAILURE
,
885 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED
);
892 /* Need RI if renegotiating */
894 && !(s
->options
& SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
)
896 SSLfatal(s
, SSL_AD_HANDSHAKE_FAILURE
,
897 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED
);
905 static int init_server_name(SSL
*s
, unsigned int context
)
908 s
->servername_done
= 0;
910 OPENSSL_free(s
->ext
.hostname
);
911 s
->ext
.hostname
= NULL
;
917 static int final_server_name(SSL
*s
, unsigned int context
, int sent
)
919 int ret
= SSL_TLSEXT_ERR_NOACK
;
920 int altmp
= SSL_AD_UNRECOGNIZED_NAME
;
921 int was_ticket
= (SSL_get_options(s
) & SSL_OP_NO_TICKET
) == 0;
923 if (!ossl_assert(s
->ctx
!= NULL
) || !ossl_assert(s
->session_ctx
!= NULL
)) {
924 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
928 if (s
->ctx
->ext
.servername_cb
!= NULL
)
929 ret
= s
->ctx
->ext
.servername_cb(s
, &altmp
,
930 s
->ctx
->ext
.servername_arg
);
931 else if (s
->session_ctx
->ext
.servername_cb
!= NULL
)
932 ret
= s
->session_ctx
->ext
.servername_cb(s
, &altmp
,
933 s
->session_ctx
->ext
.servername_arg
);
936 * For servers, propagate the SNI hostname from the temporary
937 * storage in the SSL to the persistent SSL_SESSION, now that we
938 * know we accepted it.
939 * Clients make this copy when parsing the server's response to
940 * the extension, which is when they find out that the negotiation
944 if (sent
&& ret
== SSL_TLSEXT_ERR_OK
&& !s
->hit
) {
945 /* Only store the hostname in the session if we accepted it. */
946 OPENSSL_free(s
->session
->ext
.hostname
);
947 s
->session
->ext
.hostname
= OPENSSL_strdup(s
->ext
.hostname
);
948 if (s
->session
->ext
.hostname
== NULL
&& s
->ext
.hostname
!= NULL
) {
949 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
955 * If we switched contexts (whether here or in the client_hello callback),
956 * move the sess_accept increment from the session_ctx to the new
957 * context, to avoid the confusing situation of having sess_accept_good
958 * exceed sess_accept (zero) for the new context.
960 if (SSL_IS_FIRST_HANDSHAKE(s
) && s
->ctx
!= s
->session_ctx
961 && s
->hello_retry_request
== SSL_HRR_NONE
) {
962 tsan_counter(&s
->ctx
->stats
.sess_accept
);
963 tsan_decr(&s
->session_ctx
->stats
.sess_accept
);
967 * If we're expecting to send a ticket, and tickets were previously enabled,
968 * and now tickets are disabled, then turn off expected ticket.
969 * Also, if this is not a resumption, create a new session ID
971 if (ret
== SSL_TLSEXT_ERR_OK
&& s
->ext
.ticket_expected
972 && was_ticket
&& (SSL_get_options(s
) & SSL_OP_NO_TICKET
) != 0) {
973 s
->ext
.ticket_expected
= 0;
975 SSL_SESSION
* ss
= SSL_get_session(s
);
978 OPENSSL_free(ss
->ext
.tick
);
981 ss
->ext
.tick_lifetime_hint
= 0;
982 ss
->ext
.tick_age_add
= 0;
983 if (!ssl_generate_session_id(s
, ss
)) {
984 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
988 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
995 case SSL_TLSEXT_ERR_ALERT_FATAL
:
996 SSLfatal(s
, altmp
, SSL_R_CALLBACK_FAILED
);
999 case SSL_TLSEXT_ERR_ALERT_WARNING
:
1000 /* TLSv1.3 doesn't have warning alerts so we suppress this */
1001 if (!SSL_IS_TLS13(s
))
1002 ssl3_send_alert(s
, SSL3_AL_WARNING
, altmp
);
1003 s
->servername_done
= 0;
1006 case SSL_TLSEXT_ERR_NOACK
:
1007 s
->servername_done
= 0;
1015 #ifndef OPENSSL_NO_EC
1016 static int final_ec_pt_formats(SSL
*s
, unsigned int context
, int sent
)
1018 unsigned long alg_k
, alg_a
;
1023 alg_k
= s
->s3
.tmp
.new_cipher
->algorithm_mkey
;
1024 alg_a
= s
->s3
.tmp
.new_cipher
->algorithm_auth
;
1027 * If we are client and using an elliptic curve cryptography cipher
1028 * suite, then if server returns an EC point formats lists extension it
1029 * must contain uncompressed.
1031 if (s
->ext
.ecpointformats
!= NULL
1032 && s
->ext
.ecpointformats_len
> 0
1033 && s
->ext
.peer_ecpointformats
!= NULL
1034 && s
->ext
.peer_ecpointformats_len
> 0
1035 && ((alg_k
& SSL_kECDHE
) || (alg_a
& SSL_aECDSA
))) {
1036 /* we are using an ECC cipher */
1038 unsigned char *list
= s
->ext
.peer_ecpointformats
;
1040 for (i
= 0; i
< s
->ext
.peer_ecpointformats_len
; i
++) {
1041 if (*list
++ == TLSEXT_ECPOINTFORMAT_uncompressed
)
1044 if (i
== s
->ext
.peer_ecpointformats_len
) {
1045 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
,
1046 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST
);
1055 static int init_session_ticket(SSL
*s
, unsigned int context
)
1058 s
->ext
.ticket_expected
= 0;
1063 #ifndef OPENSSL_NO_OCSP
1064 static int init_status_request(SSL
*s
, unsigned int context
)
1067 s
->ext
.status_type
= TLSEXT_STATUSTYPE_nothing
;
1070 * Ensure we get sensible values passed to tlsext_status_cb in the event
1071 * that we don't receive a status message
1073 OPENSSL_free(s
->ext
.ocsp
.resp
);
1074 s
->ext
.ocsp
.resp
= NULL
;
1075 s
->ext
.ocsp
.resp_len
= 0;
1082 #ifndef OPENSSL_NO_NEXTPROTONEG
1083 static int init_npn(SSL
*s
, unsigned int context
)
1091 static int init_alpn(SSL
*s
, unsigned int context
)
1093 OPENSSL_free(s
->s3
.alpn_selected
);
1094 s
->s3
.alpn_selected
= NULL
;
1095 s
->s3
.alpn_selected_len
= 0;
1097 OPENSSL_free(s
->s3
.alpn_proposed
);
1098 s
->s3
.alpn_proposed
= NULL
;
1099 s
->s3
.alpn_proposed_len
= 0;
1104 static int final_alpn(SSL
*s
, unsigned int context
, int sent
)
1106 if (!s
->server
&& !sent
&& s
->session
->ext
.alpn_selected
!= NULL
)
1107 s
->ext
.early_data_ok
= 0;
1109 if (!s
->server
|| !SSL_IS_TLS13(s
))
1113 * Call alpn_select callback if needed. Has to be done after SNI and
1114 * cipher negotiation (HTTP/2 restricts permitted ciphers). In TLSv1.3
1115 * we also have to do this before we decide whether to accept early_data.
1116 * In TLSv1.3 we've already negotiated our cipher so we do this call now.
1117 * For < TLSv1.3 we defer it until after cipher negotiation.
1119 * On failure SSLfatal() already called.
1121 return tls_handle_alpn(s
);
1124 static int init_sig_algs(SSL
*s
, unsigned int context
)
1126 /* Clear any signature algorithms extension received */
1127 OPENSSL_free(s
->s3
.tmp
.peer_sigalgs
);
1128 s
->s3
.tmp
.peer_sigalgs
= NULL
;
1133 static int init_sig_algs_cert(SSL
*s
, ossl_unused
unsigned int context
)
1135 /* Clear any signature algorithms extension received */
1136 OPENSSL_free(s
->s3
.tmp
.peer_cert_sigalgs
);
1137 s
->s3
.tmp
.peer_cert_sigalgs
= NULL
;
1142 #ifndef OPENSSL_NO_SRP
1143 static int init_srp(SSL
*s
, unsigned int context
)
1145 OPENSSL_free(s
->srp_ctx
.login
);
1146 s
->srp_ctx
.login
= NULL
;
1152 static int init_etm(SSL
*s
, unsigned int context
)
1159 static int init_ems(SSL
*s
, unsigned int context
)
1161 if (s
->s3
.flags
& TLS1_FLAGS_RECEIVED_EXTMS
) {
1162 s
->s3
.flags
&= ~TLS1_FLAGS_RECEIVED_EXTMS
;
1163 s
->s3
.flags
|= TLS1_FLAGS_REQUIRED_EXTMS
;
1169 static int final_ems(SSL
*s
, unsigned int context
, int sent
)
1172 * Check extended master secret extension is not dropped on
1175 if (!(s
->s3
.flags
& TLS1_FLAGS_RECEIVED_EXTMS
)
1176 && (s
->s3
.flags
& TLS1_FLAGS_REQUIRED_EXTMS
)) {
1177 SSLfatal(s
, SSL_AD_HANDSHAKE_FAILURE
, SSL_R_INCONSISTENT_EXTMS
);
1180 if (!s
->server
&& s
->hit
) {
1182 * Check extended master secret extension is consistent with
1185 if (!(s
->s3
.flags
& TLS1_FLAGS_RECEIVED_EXTMS
) !=
1186 !(s
->session
->flags
& SSL_SESS_FLAG_EXTMS
)) {
1187 SSLfatal(s
, SSL_AD_HANDSHAKE_FAILURE
, SSL_R_INCONSISTENT_EXTMS
);
1195 static int init_certificate_authorities(SSL
*s
, unsigned int context
)
1197 sk_X509_NAME_pop_free(s
->s3
.tmp
.peer_ca_names
, X509_NAME_free
);
1198 s
->s3
.tmp
.peer_ca_names
= NULL
;
1202 static EXT_RETURN
tls_construct_certificate_authorities(SSL
*s
, WPACKET
*pkt
,
1203 unsigned int context
,
1207 const STACK_OF(X509_NAME
) *ca_sk
= get_ca_names(s
);
1209 if (ca_sk
== NULL
|| sk_X509_NAME_num(ca_sk
) == 0)
1210 return EXT_RETURN_NOT_SENT
;
1212 if (!WPACKET_put_bytes_u16(pkt
, TLSEXT_TYPE_certificate_authorities
)
1213 || !WPACKET_start_sub_packet_u16(pkt
)) {
1214 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1215 return EXT_RETURN_FAIL
;
1218 if (!construct_ca_names(s
, ca_sk
, pkt
)) {
1219 /* SSLfatal() already called */
1220 return EXT_RETURN_FAIL
;
1223 if (!WPACKET_close(pkt
)) {
1224 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1225 return EXT_RETURN_FAIL
;
1228 return EXT_RETURN_SENT
;
1231 static int tls_parse_certificate_authorities(SSL
*s
, PACKET
*pkt
,
1232 unsigned int context
, X509
*x
,
1235 if (!parse_ca_names(s
, pkt
))
1237 if (PACKET_remaining(pkt
) != 0) {
1238 SSLfatal(s
, SSL_AD_DECODE_ERROR
, SSL_R_BAD_EXTENSION
);
1244 #ifndef OPENSSL_NO_SRTP
1245 static int init_srtp(SSL
*s
, unsigned int context
)
1248 s
->srtp_profile
= NULL
;
1254 static int final_sig_algs(SSL
*s
, unsigned int context
, int sent
)
1256 if (!sent
&& SSL_IS_TLS13(s
) && !s
->hit
) {
1257 SSLfatal(s
, TLS13_AD_MISSING_EXTENSION
,
1258 SSL_R_MISSING_SIGALGS_EXTENSION
);
1265 static int final_key_share(SSL
*s
, unsigned int context
, int sent
)
1267 #if !defined(OPENSSL_NO_TLS1_3)
1268 if (!SSL_IS_TLS13(s
))
1271 /* Nothing to do for key_share in an HRR */
1272 if ((context
& SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
) != 0)
1279 * we have no key_share
1281 * (we are not resuming
1282 * OR the kex_mode doesn't allow non key_share resumes)
1289 || (s
->ext
.psk_kex_mode
& TLSEXT_KEX_MODE_FLAG_KE
) == 0)) {
1290 /* Nothing left we can do - just fail */
1291 SSLfatal(s
, SSL_AD_MISSING_EXTENSION
, SSL_R_NO_SUITABLE_KEY_SHARE
);
1299 * we have a suitable key_share
1302 * we are stateless AND we have no cookie
1304 * send a HelloRetryRequest
1307 * we didn't already send a HelloRetryRequest
1309 * the client sent a key_share extension
1311 * (we are not resuming
1312 * OR the kex_mode allows key_share resumes)
1314 * a shared group exists
1316 * send a HelloRetryRequest
1318 * we are not resuming
1320 * the kex_mode doesn't allow non key_share resumes
1324 * we are stateless AND we have no cookie
1326 * send a HelloRetryRequest
1329 if (s
->s3
.peer_tmp
!= NULL
) {
1330 /* We have a suitable key_share */
1331 if ((s
->s3
.flags
& TLS1_FLAGS_STATELESS
) != 0
1332 && !s
->ext
.cookieok
) {
1333 if (!ossl_assert(s
->hello_retry_request
== SSL_HRR_NONE
)) {
1335 * If we are stateless then we wouldn't know about any
1336 * previously sent HRR - so how can this be anything other
1339 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1342 s
->hello_retry_request
= SSL_HRR_PENDING
;
1346 /* No suitable key_share */
1347 if (s
->hello_retry_request
== SSL_HRR_NONE
&& sent
1349 || (s
->ext
.psk_kex_mode
& TLSEXT_KEX_MODE_FLAG_KE_DHE
)
1351 const uint16_t *pgroups
, *clntgroups
;
1352 size_t num_groups
, clnt_num_groups
, i
;
1353 unsigned int group_id
= 0;
1355 /* Check if a shared group exists */
1357 /* Get the clients list of supported groups. */
1358 tls1_get_peer_groups(s
, &clntgroups
, &clnt_num_groups
);
1359 tls1_get_supported_groups(s
, &pgroups
, &num_groups
);
1362 * Find the first group we allow that is also in client's list
1364 for (i
= 0; i
< num_groups
; i
++) {
1365 group_id
= pgroups
[i
];
1367 if (check_in_list(s
, group_id
, clntgroups
, clnt_num_groups
,
1372 if (i
< num_groups
) {
1373 /* A shared group exists so send a HelloRetryRequest */
1374 s
->s3
.group_id
= group_id
;
1375 s
->hello_retry_request
= SSL_HRR_PENDING
;
1380 || (s
->ext
.psk_kex_mode
& TLSEXT_KEX_MODE_FLAG_KE
) == 0) {
1381 /* Nothing left we can do - just fail */
1382 SSLfatal(s
, sent
? SSL_AD_HANDSHAKE_FAILURE
1383 : SSL_AD_MISSING_EXTENSION
,
1384 SSL_R_NO_SUITABLE_KEY_SHARE
);
1388 if ((s
->s3
.flags
& TLS1_FLAGS_STATELESS
) != 0
1389 && !s
->ext
.cookieok
) {
1390 if (!ossl_assert(s
->hello_retry_request
== SSL_HRR_NONE
)) {
1392 * If we are stateless then we wouldn't know about any
1393 * previously sent HRR - so how can this be anything other
1396 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1399 s
->hello_retry_request
= SSL_HRR_PENDING
;
1405 * We have a key_share so don't send any more HelloRetryRequest
1408 if (s
->hello_retry_request
== SSL_HRR_PENDING
)
1409 s
->hello_retry_request
= SSL_HRR_COMPLETE
;
1412 * For a client side resumption with no key_share we need to generate
1413 * the handshake secret (otherwise this is done during key_share
1416 if (!sent
&& !tls13_generate_handshake_secret(s
, NULL
, 0)) {
1417 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1421 #endif /* !defined(OPENSSL_NO_TLS1_3) */
1425 static int init_psk_kex_modes(SSL
*s
, unsigned int context
)
1427 s
->ext
.psk_kex_mode
= TLSEXT_KEX_MODE_FLAG_NONE
;
1431 int tls_psk_do_binder(SSL
*s
, const EVP_MD
*md
, const unsigned char *msgstart
,
1432 size_t binderoffset
, const unsigned char *binderin
,
1433 unsigned char *binderout
, SSL_SESSION
*sess
, int sign
,
1436 EVP_PKEY
*mackey
= NULL
;
1437 EVP_MD_CTX
*mctx
= NULL
;
1438 unsigned char hash
[EVP_MAX_MD_SIZE
], binderkey
[EVP_MAX_MD_SIZE
];
1439 unsigned char finishedkey
[EVP_MAX_MD_SIZE
], tmpbinder
[EVP_MAX_MD_SIZE
];
1440 unsigned char *early_secret
;
1441 #ifdef CHARSET_EBCDIC
1442 static const unsigned char resumption_label
[] = { 0x72, 0x65, 0x73, 0x20, 0x62, 0x69, 0x6E, 0x64, 0x65, 0x72, 0x00 };
1443 static const unsigned char external_label
[] = { 0x65, 0x78, 0x74, 0x20, 0x62, 0x69, 0x6E, 0x64, 0x65, 0x72, 0x00 };
1445 static const unsigned char resumption_label
[] = "res binder";
1446 static const unsigned char external_label
[] = "ext binder";
1448 const unsigned char *label
;
1449 size_t bindersize
, labelsize
, hashsize
;
1450 int hashsizei
= EVP_MD_size(md
);
1452 int usepskfored
= 0;
1454 /* Ensure cast to size_t is safe */
1455 if (!ossl_assert(hashsizei
>= 0)) {
1456 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1459 hashsize
= (size_t)hashsizei
;
1462 && s
->early_data_state
== SSL_EARLY_DATA_CONNECTING
1463 && s
->session
->ext
.max_early_data
== 0
1464 && sess
->ext
.max_early_data
> 0)
1468 label
= external_label
;
1469 labelsize
= sizeof(external_label
) - 1;
1471 label
= resumption_label
;
1472 labelsize
= sizeof(resumption_label
) - 1;
1476 * Generate the early_secret. On the server side we've selected a PSK to
1477 * resume with (internal or external) so we always do this. On the client
1478 * side we do this for a non-external (i.e. resumption) PSK or external PSK
1479 * that will be used for early_data so that it is in place for sending early
1480 * data. For client side external PSK not being used for early_data we
1481 * generate it but store it away for later use.
1483 if (s
->server
|| !external
|| usepskfored
)
1484 early_secret
= (unsigned char *)s
->early_secret
;
1486 early_secret
= (unsigned char *)sess
->early_secret
;
1488 if (!tls13_generate_secret(s
, md
, NULL
, sess
->master_key
,
1489 sess
->master_key_length
, early_secret
)) {
1490 /* SSLfatal() already called */
1495 * Create the handshake hash for the binder key...the messages so far are
1498 mctx
= EVP_MD_CTX_new();
1500 || EVP_DigestInit_ex(mctx
, md
, NULL
) <= 0
1501 || EVP_DigestFinal_ex(mctx
, hash
, NULL
) <= 0) {
1502 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1506 /* Generate the binder key */
1507 if (!tls13_hkdf_expand(s
, md
, early_secret
, label
, labelsize
, hash
,
1508 hashsize
, binderkey
, hashsize
, 1)) {
1509 /* SSLfatal() already called */
1513 /* Generate the finished key */
1514 if (!tls13_derive_finishedkey(s
, md
, binderkey
, finishedkey
, hashsize
)) {
1515 /* SSLfatal() already called */
1519 if (EVP_DigestInit_ex(mctx
, md
, NULL
) <= 0) {
1520 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1525 * Get a hash of the ClientHello up to the start of the binders. If we are
1526 * following a HelloRetryRequest then this includes the hash of the first
1527 * ClientHello and the HelloRetryRequest itself.
1529 if (s
->hello_retry_request
== SSL_HRR_PENDING
) {
1534 hdatalen
= hdatalen_l
=
1535 BIO_get_mem_data(s
->s3
.handshake_buffer
, &hdata
);
1536 if (hdatalen_l
<= 0) {
1537 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_R_BAD_HANDSHAKE_LENGTH
);
1542 * For servers the handshake buffer data will include the second
1543 * ClientHello - which we don't want - so we need to take that bit off.
1546 PACKET hashprefix
, msg
;
1548 /* Find how many bytes are left after the first two messages */
1549 if (!PACKET_buf_init(&hashprefix
, hdata
, hdatalen
)
1550 || !PACKET_forward(&hashprefix
, 1)
1551 || !PACKET_get_length_prefixed_3(&hashprefix
, &msg
)
1552 || !PACKET_forward(&hashprefix
, 1)
1553 || !PACKET_get_length_prefixed_3(&hashprefix
, &msg
)) {
1554 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1557 hdatalen
-= PACKET_remaining(&hashprefix
);
1560 if (EVP_DigestUpdate(mctx
, hdata
, hdatalen
) <= 0) {
1561 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1566 if (EVP_DigestUpdate(mctx
, msgstart
, binderoffset
) <= 0
1567 || EVP_DigestFinal_ex(mctx
, hash
, NULL
) <= 0) {
1568 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1572 mackey
= EVP_PKEY_new_raw_private_key_ex(s
->ctx
->libctx
, "HMAC",
1573 s
->ctx
->propq
, finishedkey
,
1575 if (mackey
== NULL
) {
1576 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1581 binderout
= tmpbinder
;
1583 bindersize
= hashsize
;
1584 if (EVP_DigestSignInit_ex(mctx
, NULL
, EVP_MD_name(md
), s
->ctx
->libctx
,
1585 s
->ctx
->propq
, mackey
) <= 0
1586 || EVP_DigestSignUpdate(mctx
, hash
, hashsize
) <= 0
1587 || EVP_DigestSignFinal(mctx
, binderout
, &bindersize
) <= 0
1588 || bindersize
!= hashsize
) {
1589 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1596 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1597 ret
= (CRYPTO_memcmp(binderin
, binderout
, hashsize
) == 0);
1599 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_BINDER_DOES_NOT_VERIFY
);
1603 OPENSSL_cleanse(binderkey
, sizeof(binderkey
));
1604 OPENSSL_cleanse(finishedkey
, sizeof(finishedkey
));
1605 EVP_PKEY_free(mackey
);
1606 EVP_MD_CTX_free(mctx
);
1611 static int final_early_data(SSL
*s
, unsigned int context
, int sent
)
1617 if (context
== SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
1619 && !s
->ext
.early_data_ok
) {
1621 * If we get here then the server accepted our early_data but we
1622 * later realised that it shouldn't have done (e.g. inconsistent
1625 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_BAD_EARLY_DATA
);
1632 if (s
->max_early_data
== 0
1634 || s
->early_data_state
!= SSL_EARLY_DATA_ACCEPTING
1635 || !s
->ext
.early_data_ok
1636 || s
->hello_retry_request
!= SSL_HRR_NONE
1637 || (s
->allow_early_data_cb
!= NULL
1638 && !s
->allow_early_data_cb(s
,
1639 s
->allow_early_data_cb_data
))) {
1640 s
->ext
.early_data
= SSL_EARLY_DATA_REJECTED
;
1642 s
->ext
.early_data
= SSL_EARLY_DATA_ACCEPTED
;
1644 if (!tls13_change_cipher_state(s
,
1645 SSL3_CC_EARLY
| SSL3_CHANGE_CIPHER_SERVER_READ
)) {
1646 /* SSLfatal() already called */
1654 static int final_maxfragmentlen(SSL
*s
, unsigned int context
, int sent
)
1657 * Session resumption on server-side with MFL extension active
1658 * BUT MFL extension packet was not resent (i.e. sent == 0)
1660 if (s
->server
&& s
->hit
&& USE_MAX_FRAGMENT_LENGTH_EXT(s
->session
)
1662 SSLfatal(s
, SSL_AD_MISSING_EXTENSION
, SSL_R_BAD_EXTENSION
);
1666 /* Current SSL buffer is lower than requested MFL */
1667 if (s
->session
&& USE_MAX_FRAGMENT_LENGTH_EXT(s
->session
)
1668 && s
->max_send_fragment
< GET_MAX_FRAGMENT_LENGTH(s
->session
))
1669 /* trigger a larger buffer reallocation */
1670 if (!ssl3_setup_buffers(s
)) {
1671 /* SSLfatal() already called */
1678 static int init_post_handshake_auth(SSL
*s
, ossl_unused
unsigned int context
)
1680 s
->post_handshake_auth
= SSL_PHA_NONE
;