2 * Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include "internal/nelem.h"
12 #include "internal/cryptlib.h"
13 #include "../ssl_locl.h"
14 #include "statem_locl.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);
50 static int final_key_share(SSL *s, unsigned int context, int sent);
52 #ifndef OPENSSL_NO_SRTP
53 static int init_srtp(SSL *s, unsigned int context);
55 static int final_sig_algs(SSL *s, unsigned int context, int sent);
56 static int final_early_data(SSL *s, unsigned int context, int sent);
57 static int final_maxfragmentlen(SSL *s, unsigned int context, int sent);
58 static int init_post_handshake_auth(SSL *s, unsigned int context);
60 /* Structure to define a built-in extension */
61 typedef struct extensions_definition_st {
62 /* The defined type for the extension */
65 * The context that this extension applies to, e.g. what messages and
70 * Initialise extension before parsing. Always called for relevant contexts
71 * even if extension not present
73 int (*init)(SSL *s, unsigned int context);
74 /* Parse extension sent from client to server */
75 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
77 /* Parse extension send from server to client */
78 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
80 /* Construct extension sent from server to client */
81 EXT_RETURN (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context,
82 X509 *x, size_t chainidx);
83 /* Construct extension sent from client to server */
84 EXT_RETURN (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context,
85 X509 *x, size_t chainidx);
87 * Finalise extension after parsing. Always called where an extensions was
88 * initialised even if the extension was not present. |sent| is set to 1 if
89 * the extension was seen, or 0 otherwise.
91 int (*final)(SSL *s, unsigned int context, int sent);
92 } EXTENSION_DEFINITION;
95 * Definitions of all built-in extensions. NOTE: Changes in the number or order
96 * of these extensions should be mirrored with equivalent changes to the
97 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h.
98 * Each extension has an initialiser, a client and
99 * server side parser and a finaliser. The initialiser is called (if the
100 * extension is relevant to the given context) even if we did not see the
101 * extension in the message that we received. The parser functions are only
102 * called if we see the extension in the message. The finalisers are always
103 * called if the initialiser was called.
104 * There are also server and client side constructor functions which are always
105 * called during message construction if the extension is relevant for the
107 * The initialisation, parsing, finalisation and construction functions are
108 * always called in the order defined in this list. Some extensions may depend
109 * on others having been processed first, so the order of this list is
111 * The extension context is defined by a series of flags which specify which
112 * messages the extension is relevant to. These flags also specify whether the
113 * extension is relevant to a particular protocol or protocol version.
115 * TODO(TLS1.3): Make sure we have a test to check the consistency of these
117 * NOTE: WebSphere Application Server 7+ cannot handle empty extensions at
118 * the end, keep these extensions before signature_algorithm.
120 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL }
121 static const EXTENSION_DEFINITION ext_defs[] = {
123 TLSEXT_TYPE_renegotiate,
124 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
125 | SSL_EXT_SSL3_ALLOWED | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
126 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate,
127 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate,
131 TLSEXT_TYPE_server_name,
132 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
133 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
135 tls_parse_ctos_server_name, tls_parse_stoc_server_name,
136 tls_construct_stoc_server_name, tls_construct_ctos_server_name,
140 TLSEXT_TYPE_max_fragment_length,
141 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
142 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
143 NULL, tls_parse_ctos_maxfragmentlen, tls_parse_stoc_maxfragmentlen,
144 tls_construct_stoc_maxfragmentlen, tls_construct_ctos_maxfragmentlen,
147 #ifndef OPENSSL_NO_SRP
150 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
151 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL
156 #ifndef OPENSSL_NO_EC
158 TLSEXT_TYPE_ec_point_formats,
159 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
160 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
161 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats,
162 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats,
167 * "supported_groups" is spread across several specifications.
168 * It was originally specified as "elliptic_curves" in RFC 4492,
169 * and broadened to include named FFDH groups by RFC 7919.
170 * Both RFCs 4492 and 7919 do not include a provision for the server
171 * to indicate to the client the complete list of groups supported
172 * by the server, with the server instead just indicating the
173 * selected group for this connection in the ServerKeyExchange
174 * message. TLS 1.3 adds a scheme for the server to indicate
175 * to the client its list of supported groups in the
176 * EncryptedExtensions message, but none of the relevant
177 * specifications permit sending supported_groups in the ServerHello.
178 * Nonetheless (possibly due to the close proximity to the
179 * "ec_point_formats" extension, which is allowed in the ServerHello),
180 * there are several servers that send this extension in the
181 * ServerHello anyway. Up to and including the 1.1.0 release,
182 * we did not check for the presence of nonpermitted extensions,
183 * so to avoid a regression, we must permit this extension in the
184 * TLS 1.2 ServerHello as well.
186 * Note that there is no tls_parse_stoc_supported_groups function,
187 * so we do not perform any additional parsing, validation, or
188 * processing on the server's group list -- this is just a minimal
189 * change to preserve compatibility with these misbehaving servers.
191 TLSEXT_TYPE_supported_groups,
192 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
193 | SSL_EXT_TLS1_2_SERVER_HELLO,
194 NULL, tls_parse_ctos_supported_groups, NULL,
195 tls_construct_stoc_supported_groups,
196 tls_construct_ctos_supported_groups, NULL
203 TLSEXT_TYPE_session_ticket,
204 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
205 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
206 init_session_ticket, tls_parse_ctos_session_ticket,
207 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket,
208 tls_construct_ctos_session_ticket, NULL
210 #ifndef OPENSSL_NO_OCSP
212 TLSEXT_TYPE_status_request,
213 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
214 | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
215 init_status_request, tls_parse_ctos_status_request,
216 tls_parse_stoc_status_request, tls_construct_stoc_status_request,
217 tls_construct_ctos_status_request, NULL
222 #ifndef OPENSSL_NO_NEXTPROTONEG
224 TLSEXT_TYPE_next_proto_neg,
225 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
226 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
227 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn,
228 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL
235 * Must appear in this list after server_name so that finalisation
236 * happens after server_name callbacks
238 TLSEXT_TYPE_application_layer_protocol_negotiation,
239 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
240 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
241 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn,
242 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn
244 #ifndef OPENSSL_NO_SRTP
246 TLSEXT_TYPE_use_srtp,
247 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
248 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS | SSL_EXT_DTLS_ONLY,
249 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp,
250 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL
256 TLSEXT_TYPE_encrypt_then_mac,
257 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
258 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
259 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm,
260 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL
262 #ifndef OPENSSL_NO_CT
264 TLSEXT_TYPE_signed_certificate_timestamp,
265 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
266 | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
269 * No server side support for this, but can be provided by a custom
270 * extension. This is an exception to the rule that custom extensions
271 * cannot override built in ones.
273 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL
279 TLSEXT_TYPE_extended_master_secret,
280 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
281 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
282 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems,
283 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems
286 TLSEXT_TYPE_signature_algorithms_cert,
287 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
288 init_sig_algs_cert, tls_parse_ctos_sig_algs_cert,
289 tls_parse_ctos_sig_algs_cert,
290 /* We do not generate signature_algorithms_cert at present. */
294 TLSEXT_TYPE_post_handshake_auth,
295 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ONLY,
296 init_post_handshake_auth,
297 tls_parse_ctos_post_handshake_auth, NULL,
298 NULL, tls_construct_ctos_post_handshake_auth,
302 TLSEXT_TYPE_signature_algorithms,
303 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
304 init_sig_algs, tls_parse_ctos_sig_algs,
305 tls_parse_ctos_sig_algs, tls_construct_ctos_sig_algs,
306 tls_construct_ctos_sig_algs, final_sig_algs
309 TLSEXT_TYPE_supported_versions,
310 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
311 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY,
313 /* Processed inline as part of version selection */
314 NULL, tls_parse_stoc_supported_versions,
315 tls_construct_stoc_supported_versions,
316 tls_construct_ctos_supported_versions, NULL
319 TLSEXT_TYPE_psk_kex_modes,
320 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY
321 | SSL_EXT_TLS1_3_ONLY,
322 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL,
323 tls_construct_ctos_psk_kex_modes, NULL
325 #ifndef OPENSSL_NO_EC
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,
341 /* Must be after key_share */
343 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST
344 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
345 NULL, tls_parse_ctos_cookie, tls_parse_stoc_cookie,
346 tls_construct_stoc_cookie, tls_construct_ctos_cookie, NULL
350 * Special unsolicited ServerHello extension only used when
351 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set. We allow it in a ClientHello but
354 TLSEXT_TYPE_cryptopro_bug,
355 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO
356 | SSL_EXT_TLS1_2_AND_BELOW_ONLY,
357 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL
360 TLSEXT_TYPE_early_data,
361 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
362 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET | SSL_EXT_TLS1_3_ONLY,
363 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data,
364 tls_construct_stoc_early_data, tls_construct_ctos_early_data,
368 TLSEXT_TYPE_certificate_authorities,
369 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
370 | SSL_EXT_TLS1_3_ONLY,
371 init_certificate_authorities,
372 tls_parse_certificate_authorities, tls_parse_certificate_authorities,
373 tls_construct_certificate_authorities,
374 tls_construct_certificate_authorities, NULL,
377 /* Must be immediately before pre_shared_key */
379 SSL_EXT_CLIENT_HELLO,
381 /* We send this, but don't read it */
382 NULL, NULL, NULL, tls_construct_ctos_padding, NULL
385 /* Required by the TLSv1.3 spec to always be the last extension */
387 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO
388 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY,
389 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk,
390 tls_construct_ctos_psk, NULL
394 /* Check whether an extension's context matches the current context */
395 static int validate_context(SSL *s, unsigned int extctx, unsigned int thisctx)
397 /* Check we're allowed to use this extension in this context */
398 if ((thisctx & extctx) == 0)
401 if (SSL_IS_DTLS(s)) {
402 if ((extctx & SSL_EXT_TLS_ONLY) != 0)
404 } else if ((extctx & SSL_EXT_DTLS_ONLY) != 0) {
411 int tls_validate_all_contexts(SSL *s, unsigned int thisctx, RAW_EXTENSION *exts)
413 size_t i, num_exts, builtin_num = OSSL_NELEM(ext_defs), offset;
414 RAW_EXTENSION *thisext;
415 unsigned int context;
416 ENDPOINT role = ENDPOINT_BOTH;
418 if ((thisctx & SSL_EXT_CLIENT_HELLO) != 0)
419 role = ENDPOINT_SERVER;
420 else if ((thisctx & SSL_EXT_TLS1_2_SERVER_HELLO) != 0)
421 role = ENDPOINT_CLIENT;
423 /* Calculate the number of extensions in the extensions list */
424 num_exts = builtin_num + s->cert->custext.meths_count;
426 for (thisext = exts, i = 0; i < num_exts; i++, thisext++) {
427 if (!thisext->present)
430 if (i < builtin_num) {
431 context = ext_defs[i].context;
433 custom_ext_method *meth = NULL;
435 meth = custom_ext_find(&s->cert->custext, role, thisext->type,
437 if (!ossl_assert(meth != NULL))
439 context = meth->context;
442 if (!validate_context(s, context, thisctx))
450 * Verify whether we are allowed to use the extension |type| in the current
451 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to
452 * indicate the extension is not allowed. If returning 1 then |*found| is set to
453 * the definition for the extension we found.
455 static int verify_extension(SSL *s, unsigned int context, unsigned int type,
456 custom_ext_methods *meths, RAW_EXTENSION *rawexlist,
457 RAW_EXTENSION **found)
460 size_t builtin_num = OSSL_NELEM(ext_defs);
461 const EXTENSION_DEFINITION *thisext;
463 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) {
464 if (type == thisext->type) {
465 if (!validate_context(s, thisext->context, context))
468 *found = &rawexlist[i];
473 /* Check the custom extensions */
476 ENDPOINT role = ENDPOINT_BOTH;
477 custom_ext_method *meth = NULL;
479 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
480 role = ENDPOINT_SERVER;
481 else if ((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0)
482 role = ENDPOINT_CLIENT;
484 meth = custom_ext_find(meths, role, type, &offset);
486 if (!validate_context(s, meth->context, context))
488 *found = &rawexlist[offset + builtin_num];
493 /* Unknown extension. We allow it */
499 * Check whether the context defined for an extension |extctx| means whether
500 * the extension is relevant for the current context |thisctx| or not. Returns
501 * 1 if the extension is relevant for this context, and 0 otherwise
503 int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx)
508 * For HRR we haven't selected the version yet but we know it will be
511 if ((thisctx & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0)
514 is_tls13 = SSL_IS_TLS13(s);
517 && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0)
518 || (s->version == SSL3_VERSION
519 && (extctx & SSL_EXT_SSL3_ALLOWED) == 0)
521 * Note that SSL_IS_TLS13() means "TLS 1.3 has been negotiated",
522 * which is never true when generating the ClientHello.
523 * However, version negotiation *has* occurred by the time the
524 * ClientHello extensions are being parsed.
525 * Be careful to allow TLS 1.3-only extensions when generating
528 || (is_tls13 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0)
529 || (!is_tls13 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0
530 && (thisctx & SSL_EXT_CLIENT_HELLO) == 0)
531 || (s->server && !is_tls13 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0)
532 || (s->hit && (extctx & SSL_EXT_IGNORE_ON_RESUMPTION) != 0))
538 * Gather a list of all the extensions from the data in |packet]. |context|
539 * tells us which message this extension is for. The raw extension data is
540 * stored in |*res| on success. We don't actually process the content of the
541 * extensions yet, except to check their types. This function also runs the
542 * initialiser functions for all known extensions if |init| is nonzero (whether
543 * we have collected them or not). If successful the caller is responsible for
544 * freeing the contents of |*res|.
546 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
547 * more than one extension of the same type in a ClientHello or ServerHello.
548 * This function returns 1 if all extensions are unique and we have parsed their
549 * types, and 0 if the extensions contain duplicates, could not be successfully
550 * found, or an internal error occurred. We only check duplicates for
551 * extensions that we know about. We ignore others.
553 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
554 RAW_EXTENSION **res, size_t *len, int init)
556 PACKET extensions = *packet;
559 custom_ext_methods *exts = &s->cert->custext;
560 RAW_EXTENSION *raw_extensions = NULL;
561 const EXTENSION_DEFINITION *thisexd;
566 * Initialise server side custom extensions. Client side is done during
567 * construction of extensions for the ClientHello.
569 if ((context & SSL_EXT_CLIENT_HELLO) != 0)
570 custom_ext_init(&s->cert->custext);
572 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0);
573 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions));
574 if (raw_extensions == NULL) {
575 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_COLLECT_EXTENSIONS,
576 ERR_R_MALLOC_FAILURE);
581 while (PACKET_remaining(&extensions) > 0) {
582 unsigned int type, idx;
584 RAW_EXTENSION *thisex;
586 if (!PACKET_get_net_2(&extensions, &type) ||
587 !PACKET_get_length_prefixed_2(&extensions, &extension)) {
588 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_COLLECT_EXTENSIONS,
589 SSL_R_BAD_EXTENSION);
593 * Verify this extension is allowed. We only check duplicates for
594 * extensions that we recognise. We also have a special case for the
595 * PSK extension, which must be the last one in the ClientHello.
597 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex)
598 || (thisex != NULL && thisex->present == 1)
599 || (type == TLSEXT_TYPE_psk
600 && (context & SSL_EXT_CLIENT_HELLO) != 0
601 && PACKET_remaining(&extensions) != 0)) {
602 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_COLLECT_EXTENSIONS,
603 SSL_R_BAD_EXTENSION);
606 idx = thisex - raw_extensions;
608 * Check that we requested this extension (if appropriate). Requests can
609 * be sent in the ClientHello and CertificateRequest. Unsolicited
610 * extensions can be sent in the NewSessionTicket. We only do this for
611 * the built-in extensions. Custom extensions have a different but
612 * similar check elsewhere.
614 * - The HRR cookie extension is unsolicited
615 * - The renegotiate extension is unsolicited (the client signals
616 * support via an SCSV)
617 * - The signed_certificate_timestamp extension can be provided by a
618 * custom extension or by the built-in version. We let the extension
619 * itself handle unsolicited response checks.
621 if (idx < OSSL_NELEM(ext_defs)
622 && (context & (SSL_EXT_CLIENT_HELLO
623 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
624 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) == 0
625 && type != TLSEXT_TYPE_cookie
626 && type != TLSEXT_TYPE_renegotiate
627 && type != TLSEXT_TYPE_signed_certificate_timestamp
628 && (s->ext.extflags[idx] & SSL_EXT_FLAG_SENT) == 0
629 #ifndef OPENSSL_NO_GOST
630 && !((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0
631 && type == TLSEXT_TYPE_cryptopro_bug)
634 SSLfatal(s, SSL_AD_UNSUPPORTED_EXTENSION,
635 SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_UNSOLICITED_EXTENSION);
638 if (thisex != NULL) {
639 thisex->data = extension;
642 thisex->received_order = i++;
644 s->ext.debug_cb(s, !s->server, thisex->type,
645 PACKET_data(&thisex->data),
646 PACKET_remaining(&thisex->data),
653 * Initialise all known extensions relevant to this context,
654 * whether we have found them or not
656 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs);
658 if (thisexd->init != NULL && (thisexd->context & context) != 0
659 && extension_is_relevant(s, thisexd->context, context)
660 && !thisexd->init(s, context)) {
661 /* SSLfatal() already called */
667 *res = raw_extensions;
673 OPENSSL_free(raw_extensions);
678 * Runs the parser for a given extension with index |idx|. |exts| contains the
679 * list of all parsed extensions previously collected by
680 * tls_collect_extensions(). The parser is only run if it is applicable for the
681 * given |context| and the parser has not already been run. If this is for a
682 * Certificate message, then we also provide the parser with the relevant
683 * Certificate |x| and its position in the |chainidx| with 0 being the first
684 * Certificate. Returns 1 on success or 0 on failure. If an extension is not
685 * present this counted as success.
687 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
688 RAW_EXTENSION *exts, X509 *x, size_t chainidx)
690 RAW_EXTENSION *currext = &exts[idx];
691 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
692 size_t chainidx) = NULL;
694 /* Skip if the extension is not present */
695 if (!currext->present)
698 /* Skip if we've already parsed this extension */
704 if (idx < OSSL_NELEM(ext_defs)) {
705 /* We are handling a built-in extension */
706 const EXTENSION_DEFINITION *extdef = &ext_defs[idx];
708 /* Check if extension is defined for our protocol. If not, skip */
709 if (!extension_is_relevant(s, extdef->context, context))
712 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc;
715 return parser(s, &currext->data, context, x, chainidx);
718 * If the parser is NULL we fall through to the custom extension
723 /* Parse custom extensions */
724 return custom_ext_parse(s, context, currext->type,
725 PACKET_data(&currext->data),
726 PACKET_remaining(&currext->data),
731 * Parse all remaining extensions that have not yet been parsed. Also calls the
732 * finalisation for all extensions at the end if |fin| is nonzero, whether we
733 * collected them or not. Returns 1 for success or 0 for failure. If we are
734 * working on a Certificate message then we also pass the Certificate |x| and
735 * its position in the |chainidx|, with 0 being the first certificate.
737 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
738 size_t chainidx, int fin)
740 size_t i, numexts = OSSL_NELEM(ext_defs);
741 const EXTENSION_DEFINITION *thisexd;
743 /* Calculate the number of extensions in the extensions list */
744 numexts += s->cert->custext.meths_count;
746 /* Parse each extension in turn */
747 for (i = 0; i < numexts; i++) {
748 if (!tls_parse_extension(s, i, context, exts, x, chainidx)) {
749 /* SSLfatal() already called */
756 * Finalise all known extensions relevant to this context,
757 * whether we have found them or not
759 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs);
761 if (thisexd->final != NULL && (thisexd->context & context) != 0
762 && !thisexd->final(s, context, exts[i].present)) {
763 /* SSLfatal() already called */
772 int should_add_extension(SSL *s, unsigned int extctx, unsigned int thisctx,
775 /* Skip if not relevant for our context */
776 if ((extctx & thisctx) == 0)
779 /* Check if this extension is defined for our protocol. If not, skip */
780 if (!extension_is_relevant(s, extctx, thisctx)
781 || ((extctx & SSL_EXT_TLS1_3_ONLY) != 0
782 && (thisctx & SSL_EXT_CLIENT_HELLO) != 0
783 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION)))
790 * Construct all the extensions relevant to the current |context| and write
791 * them to |pkt|. If this is an extension for a Certificate in a Certificate
792 * message, then |x| will be set to the Certificate we are handling, and
793 * |chainidx| will indicate the position in the chainidx we are processing (with
794 * 0 being the first in the chain). Returns 1 on success or 0 on failure. On a
795 * failure construction stops at the first extension to fail to construct.
797 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
798 X509 *x, size_t chainidx)
801 int min_version, max_version = 0, reason;
802 const EXTENSION_DEFINITION *thisexd;
804 if (!WPACKET_start_sub_packet_u16(pkt)
806 * If extensions are of zero length then we don't even add the
807 * extensions length bytes to a ClientHello/ServerHello
811 (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0
812 && !WPACKET_set_flags(pkt,
813 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) {
814 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS,
815 ERR_R_INTERNAL_ERROR);
819 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
820 reason = ssl_get_min_max_version(s, &min_version, &max_version, NULL);
822 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS,
828 /* Add custom extensions first */
829 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
830 /* On the server side with initialise during ClientHello parsing */
831 custom_ext_init(&s->cert->custext);
833 if (!custom_ext_add(s, context, pkt, x, chainidx, max_version)) {
834 /* SSLfatal() already called */
838 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
839 EXT_RETURN (*construct)(SSL *s, WPACKET *pkt, unsigned int context,
840 X509 *x, size_t chainidx);
843 /* Skip if not relevant for our context */
844 if (!should_add_extension(s, thisexd->context, context, max_version))
847 construct = s->server ? thisexd->construct_stoc
848 : thisexd->construct_ctos;
850 if (construct == NULL)
853 ret = construct(s, pkt, context, x, chainidx);
854 if (ret == EXT_RETURN_FAIL) {
855 /* SSLfatal() already called */
858 if (ret == EXT_RETURN_SENT
859 && (context & (SSL_EXT_CLIENT_HELLO
860 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST
861 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) != 0)
862 s->ext.extflags[i] |= SSL_EXT_FLAG_SENT;
865 if (!WPACKET_close(pkt)) {
866 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS,
867 ERR_R_INTERNAL_ERROR);
875 * Built in extension finalisation and initialisation functions. All initialise
876 * or finalise the associated extension type for the given |context|. For
877 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0
878 * otherwise. These functions return 1 on success or 0 on failure.
881 static int final_renegotiate(SSL *s, unsigned int context, int sent)
885 * Check if we can connect to a server that doesn't support safe
888 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
889 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
891 SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_RENEGOTIATE,
892 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
899 /* Need RI if renegotiating */
901 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)
903 SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_RENEGOTIATE,
904 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
912 static int init_server_name(SSL *s, unsigned int context)
915 s->servername_done = 0;
917 OPENSSL_free(s->ext.hostname);
918 s->ext.hostname = NULL;
924 static int final_server_name(SSL *s, unsigned int context, int sent)
926 int ret = SSL_TLSEXT_ERR_NOACK;
927 int altmp = SSL_AD_UNRECOGNIZED_NAME;
928 int was_ticket = (SSL_get_options(s) & SSL_OP_NO_TICKET) == 0;
930 if (!ossl_assert(s->ctx != NULL) || !ossl_assert(s->session_ctx != NULL)) {
931 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME,
932 ERR_R_INTERNAL_ERROR);
936 if (s->ctx->ext.servername_cb != NULL)
937 ret = s->ctx->ext.servername_cb(s, &altmp,
938 s->ctx->ext.servername_arg);
939 else if (s->session_ctx->ext.servername_cb != NULL)
940 ret = s->session_ctx->ext.servername_cb(s, &altmp,
941 s->session_ctx->ext.servername_arg);
944 * For servers, propagate the SNI hostname from the temporary
945 * storage in the SSL to the persistent SSL_SESSION, now that we
946 * know we accepted it.
947 * Clients make this copy when parsing the server's response to
948 * the extension, which is when they find out that the negotiation
952 /* TODO(OpenSSL1.2) revisit !sent case */
953 if (sent && ret == SSL_TLSEXT_ERR_OK && (!s->hit || SSL_IS_TLS13(s))) {
954 /* Only store the hostname in the session if we accepted it. */
955 OPENSSL_free(s->session->ext.hostname);
956 s->session->ext.hostname = OPENSSL_strdup(s->ext.hostname);
957 if (s->session->ext.hostname == NULL && s->ext.hostname != NULL) {
958 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME,
959 ERR_R_INTERNAL_ERROR);
965 * If we switched contexts (whether here or in the client_hello callback),
966 * move the sess_accept increment from the session_ctx to the new
967 * context, to avoid the confusing situation of having sess_accept_good
968 * exceed sess_accept (zero) for the new context.
970 if (SSL_IS_FIRST_HANDSHAKE(s) && s->ctx != s->session_ctx) {
971 tsan_counter(&s->ctx->stats.sess_accept);
972 tsan_decr(&s->session_ctx->stats.sess_accept);
976 * If we're expecting to send a ticket, and tickets were previously enabled,
977 * and now tickets are disabled, then turn off expected ticket.
978 * Also, if this is not a resumption, create a new session ID
980 if (ret == SSL_TLSEXT_ERR_OK && s->ext.ticket_expected
981 && was_ticket && (SSL_get_options(s) & SSL_OP_NO_TICKET) != 0) {
982 s->ext.ticket_expected = 0;
984 SSL_SESSION* ss = SSL_get_session(s);
987 OPENSSL_free(ss->ext.tick);
990 ss->ext.tick_lifetime_hint = 0;
991 ss->ext.tick_age_add = 0;
992 ss->ext.tick_identity = 0;
993 if (!ssl_generate_session_id(s, ss)) {
994 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME,
995 ERR_R_INTERNAL_ERROR);
999 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME,
1000 ERR_R_INTERNAL_ERROR);
1007 case SSL_TLSEXT_ERR_ALERT_FATAL:
1008 SSLfatal(s, altmp, SSL_F_FINAL_SERVER_NAME, SSL_R_CALLBACK_FAILED);
1011 case SSL_TLSEXT_ERR_ALERT_WARNING:
1012 /* TLSv1.3 doesn't have warning alerts so we suppress this */
1013 if (!SSL_IS_TLS13(s))
1014 ssl3_send_alert(s, SSL3_AL_WARNING, altmp);
1017 case SSL_TLSEXT_ERR_NOACK:
1018 s->servername_done = 0;
1026 #ifndef OPENSSL_NO_EC
1027 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent)
1029 unsigned long alg_k, alg_a;
1034 alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
1035 alg_a = s->s3->tmp.new_cipher->algorithm_auth;
1038 * If we are client and using an elliptic curve cryptography cipher
1039 * suite, then if server returns an EC point formats lists extension it
1040 * must contain uncompressed.
1042 if (s->ext.ecpointformats != NULL
1043 && s->ext.ecpointformats_len > 0
1044 && s->session->ext.ecpointformats != NULL
1045 && s->session->ext.ecpointformats_len > 0
1046 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
1047 /* we are using an ECC cipher */
1049 unsigned char *list = s->session->ext.ecpointformats;
1051 for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
1052 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed)
1055 if (i == s->session->ext.ecpointformats_len) {
1056 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_FINAL_EC_PT_FORMATS,
1057 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
1066 static int init_session_ticket(SSL *s, unsigned int context)
1069 s->ext.ticket_expected = 0;
1074 #ifndef OPENSSL_NO_OCSP
1075 static int init_status_request(SSL *s, unsigned int context)
1078 s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
1081 * Ensure we get sensible values passed to tlsext_status_cb in the event
1082 * that we don't receive a status message
1084 OPENSSL_free(s->ext.ocsp.resp);
1085 s->ext.ocsp.resp = NULL;
1086 s->ext.ocsp.resp_len = 0;
1093 #ifndef OPENSSL_NO_NEXTPROTONEG
1094 static int init_npn(SSL *s, unsigned int context)
1096 s->s3->npn_seen = 0;
1102 static int init_alpn(SSL *s, unsigned int context)
1104 OPENSSL_free(s->s3->alpn_selected);
1105 s->s3->alpn_selected = NULL;
1106 s->s3->alpn_selected_len = 0;
1108 OPENSSL_free(s->s3->alpn_proposed);
1109 s->s3->alpn_proposed = NULL;
1110 s->s3->alpn_proposed_len = 0;
1115 static int final_alpn(SSL *s, unsigned int context, int sent)
1117 if (!s->server && !sent && s->session->ext.alpn_selected != NULL)
1118 s->ext.early_data_ok = 0;
1120 if (!s->server || !SSL_IS_TLS13(s))
1124 * Call alpn_select callback if needed. Has to be done after SNI and
1125 * cipher negotiation (HTTP/2 restricts permitted ciphers). In TLSv1.3
1126 * we also have to do this before we decide whether to accept early_data.
1127 * In TLSv1.3 we've already negotiated our cipher so we do this call now.
1128 * For < TLSv1.3 we defer it until after cipher negotiation.
1130 * On failure SSLfatal() already called.
1132 return tls_handle_alpn(s);
1135 static int init_sig_algs(SSL *s, unsigned int context)
1137 /* Clear any signature algorithms extension received */
1138 OPENSSL_free(s->s3->tmp.peer_sigalgs);
1139 s->s3->tmp.peer_sigalgs = NULL;
1144 static int init_sig_algs_cert(SSL *s, unsigned int context)
1146 /* Clear any signature algorithms extension received */
1147 OPENSSL_free(s->s3->tmp.peer_cert_sigalgs);
1148 s->s3->tmp.peer_cert_sigalgs = NULL;
1153 #ifndef OPENSSL_NO_SRP
1154 static int init_srp(SSL *s, unsigned int context)
1156 OPENSSL_free(s->srp_ctx.login);
1157 s->srp_ctx.login = NULL;
1163 static int init_etm(SSL *s, unsigned int context)
1170 static int init_ems(SSL *s, unsigned int context)
1173 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
1178 static int final_ems(SSL *s, unsigned int context, int sent)
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_F_FINAL_EMS,
1188 SSL_R_INCONSISTENT_EXTMS);
1196 static int init_certificate_authorities(SSL *s, unsigned int context)
1198 sk_X509_NAME_pop_free(s->s3->tmp.peer_ca_names, X509_NAME_free);
1199 s->s3->tmp.peer_ca_names = NULL;
1203 static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt,
1204 unsigned int context,
1208 const STACK_OF(X509_NAME) *ca_sk = get_ca_names(s);
1210 if (ca_sk == NULL || sk_X509_NAME_num(ca_sk) == 0)
1211 return EXT_RETURN_NOT_SENT;
1213 if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_certificate_authorities)
1214 || !WPACKET_start_sub_packet_u16(pkt)) {
1215 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1216 SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,
1217 ERR_R_INTERNAL_ERROR);
1218 return EXT_RETURN_FAIL;
1221 if (!construct_ca_names(s, ca_sk, pkt)) {
1222 /* SSLfatal() already called */
1223 return EXT_RETURN_FAIL;
1226 if (!WPACKET_close(pkt)) {
1227 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1228 SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES,
1229 ERR_R_INTERNAL_ERROR);
1230 return EXT_RETURN_FAIL;
1233 return EXT_RETURN_SENT;
1236 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt,
1237 unsigned int context, X509 *x,
1240 if (!parse_ca_names(s, pkt))
1242 if (PACKET_remaining(pkt) != 0) {
1243 SSLfatal(s, SSL_AD_DECODE_ERROR,
1244 SSL_F_TLS_PARSE_CERTIFICATE_AUTHORITIES, SSL_R_BAD_EXTENSION);
1250 #ifndef OPENSSL_NO_SRTP
1251 static int init_srtp(SSL *s, unsigned int context)
1254 s->srtp_profile = NULL;
1260 static int final_sig_algs(SSL *s, unsigned int context, int sent)
1262 if (!sent && SSL_IS_TLS13(s) && !s->hit) {
1263 SSLfatal(s, TLS13_AD_MISSING_EXTENSION, SSL_F_FINAL_SIG_ALGS,
1264 SSL_R_MISSING_SIGALGS_EXTENSION);
1271 #ifndef OPENSSL_NO_EC
1272 static int final_key_share(SSL *s, unsigned int context, int sent)
1274 if (!SSL_IS_TLS13(s))
1277 /* Nothing to do for key_share in an HRR */
1278 if ((context & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0)
1285 * we have no key_share
1287 * (we are not resuming
1288 * OR the kex_mode doesn't allow non key_share resumes)
1295 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) {
1296 /* Nothing left we can do - just fail */
1297 SSLfatal(s, SSL_AD_MISSING_EXTENSION, SSL_F_FINAL_KEY_SHARE,
1298 SSL_R_NO_SUITABLE_KEY_SHARE);
1306 * we have a suitable key_share
1309 * we are stateless AND we have no cookie
1311 * send a HelloRetryRequest
1314 * we didn't already send a HelloRetryRequest
1316 * the client sent a key_share extension
1318 * (we are not resuming
1319 * OR the kex_mode allows key_share resumes)
1321 * a shared group exists
1323 * send a HelloRetryRequest
1325 * we are not resuming
1327 * the kex_mode doesn't allow non key_share resumes
1331 * we are stateless AND we have no cookie
1333 * send a HelloRetryRequest
1336 if (s->s3->peer_tmp != NULL) {
1337 /* We have a suitable key_share */
1338 if ((s->s3->flags & TLS1_FLAGS_STATELESS) != 0
1339 && !s->ext.cookieok) {
1340 if (!ossl_assert(s->hello_retry_request == SSL_HRR_NONE)) {
1342 * If we are stateless then we wouldn't know about any
1343 * previously sent HRR - so how can this be anything other
1346 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE,
1347 ERR_R_INTERNAL_ERROR);
1350 s->hello_retry_request = SSL_HRR_PENDING;
1354 /* No suitable key_share */
1355 if (s->hello_retry_request == SSL_HRR_NONE && sent
1357 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE)
1359 const uint16_t *pgroups, *clntgroups;
1360 size_t num_groups, clnt_num_groups, i;
1361 unsigned int group_id = 0;
1363 /* Check if a shared group exists */
1365 /* Get the clients list of supported groups. */
1366 tls1_get_peer_groups(s, &clntgroups, &clnt_num_groups);
1367 tls1_get_supported_groups(s, &pgroups, &num_groups);
1370 * Find the first group we allow that is also in client's list
1372 for (i = 0; i < num_groups; i++) {
1373 group_id = pgroups[i];
1375 if (check_in_list(s, group_id, clntgroups, clnt_num_groups,
1380 if (i < num_groups) {
1381 /* A shared group exists so send a HelloRetryRequest */
1382 s->s3->group_id = group_id;
1383 s->hello_retry_request = SSL_HRR_PENDING;
1388 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) {
1389 /* Nothing left we can do - just fail */
1390 SSLfatal(s, sent ? SSL_AD_HANDSHAKE_FAILURE
1391 : SSL_AD_MISSING_EXTENSION,
1392 SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE);
1396 if ((s->s3->flags & TLS1_FLAGS_STATELESS) != 0
1397 && !s->ext.cookieok) {
1398 if (!ossl_assert(s->hello_retry_request == SSL_HRR_NONE)) {
1400 * If we are stateless then we wouldn't know about any
1401 * previously sent HRR - so how can this be anything other
1404 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE,
1405 ERR_R_INTERNAL_ERROR);
1408 s->hello_retry_request = SSL_HRR_PENDING;
1414 * We have a key_share so don't send any more HelloRetryRequest
1417 if (s->hello_retry_request == SSL_HRR_PENDING)
1418 s->hello_retry_request = SSL_HRR_COMPLETE;
1421 * For a client side resumption with no key_share we need to generate
1422 * the handshake secret (otherwise this is done during key_share
1425 if (!sent && !tls13_generate_handshake_secret(s, NULL, 0)) {
1426 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE,
1427 ERR_R_INTERNAL_ERROR);
1436 static int init_psk_kex_modes(SSL *s, unsigned int context)
1438 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE;
1442 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
1443 size_t binderoffset, const unsigned char *binderin,
1444 unsigned char *binderout, SSL_SESSION *sess, int sign,
1447 EVP_PKEY *mackey = NULL;
1448 EVP_MD_CTX *mctx = NULL;
1449 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE];
1450 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE];
1451 unsigned char *early_secret;
1452 static const unsigned char resumption_label[] = "res binder";
1453 static const unsigned char external_label[] = "ext binder";
1454 const unsigned char *label;
1455 size_t bindersize, labelsize, hashsize;
1456 int hashsizei = EVP_MD_size(md);
1458 int usepskfored = 0;
1460 /* Ensure cast to size_t is safe */
1461 if (!ossl_assert(hashsizei >= 0)) {
1462 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1463 ERR_R_INTERNAL_ERROR);
1466 hashsize = (size_t)hashsizei;
1469 && s->early_data_state == SSL_EARLY_DATA_CONNECTING
1470 && s->session->ext.max_early_data == 0
1471 && sess->ext.max_early_data > 0)
1475 label = external_label;
1476 labelsize = sizeof(external_label) - 1;
1478 label = resumption_label;
1479 labelsize = sizeof(resumption_label) - 1;
1483 * Generate the early_secret. On the server side we've selected a PSK to
1484 * resume with (internal or external) so we always do this. On the client
1485 * side we do this for a non-external (i.e. resumption) PSK or external PSK
1486 * that will be used for early_data so that it is in place for sending early
1487 * data. For client side external PSK not being used for early_data we
1488 * generate it but store it away for later use.
1490 if (s->server || !external || usepskfored)
1491 early_secret = (unsigned char *)s->early_secret;
1493 early_secret = (unsigned char *)sess->early_secret;
1495 if (!tls13_generate_secret(s, md, NULL, sess->master_key,
1496 sess->master_key_length, early_secret)) {
1497 /* SSLfatal() already called */
1502 * Create the handshake hash for the binder key...the messages so far are
1505 mctx = EVP_MD_CTX_new();
1507 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
1508 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1509 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1510 ERR_R_INTERNAL_ERROR);
1514 /* Generate the binder key */
1515 if (!tls13_hkdf_expand(s, md, early_secret, label, labelsize, hash,
1516 hashsize, binderkey, hashsize, 1)) {
1517 /* SSLfatal() already called */
1521 /* Generate the finished key */
1522 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) {
1523 /* SSLfatal() already called */
1527 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) {
1528 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1529 ERR_R_INTERNAL_ERROR);
1534 * Get a hash of the ClientHello up to the start of the binders. If we are
1535 * following a HelloRetryRequest then this includes the hash of the first
1536 * ClientHello and the HelloRetryRequest itself.
1538 if (s->hello_retry_request == SSL_HRR_PENDING) {
1543 hdatalen = hdatalen_l =
1544 BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
1545 if (hdatalen_l <= 0) {
1546 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1547 SSL_R_BAD_HANDSHAKE_LENGTH);
1552 * For servers the handshake buffer data will include the second
1553 * ClientHello - which we don't want - so we need to take that bit off.
1556 PACKET hashprefix, msg;
1558 /* Find how many bytes are left after the first two messages */
1559 if (!PACKET_buf_init(&hashprefix, hdata, hdatalen)
1560 || !PACKET_forward(&hashprefix, 1)
1561 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)
1562 || !PACKET_forward(&hashprefix, 1)
1563 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)) {
1564 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1565 ERR_R_INTERNAL_ERROR);
1568 hdatalen -= PACKET_remaining(&hashprefix);
1571 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) {
1572 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1573 ERR_R_INTERNAL_ERROR);
1578 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0
1579 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
1580 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1581 ERR_R_INTERNAL_ERROR);
1585 mackey = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finishedkey,
1587 if (mackey == NULL) {
1588 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1589 ERR_R_INTERNAL_ERROR);
1594 binderout = tmpbinder;
1596 bindersize = hashsize;
1597 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0
1598 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0
1599 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0
1600 || bindersize != hashsize) {
1601 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER,
1602 ERR_R_INTERNAL_ERROR);
1609 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */
1610 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0);
1612 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PSK_DO_BINDER,
1613 SSL_R_BINDER_DOES_NOT_VERIFY);
1617 OPENSSL_cleanse(binderkey, sizeof(binderkey));
1618 OPENSSL_cleanse(finishedkey, sizeof(finishedkey));
1619 EVP_PKEY_free(mackey);
1620 EVP_MD_CTX_free(mctx);
1625 static int final_early_data(SSL *s, unsigned int context, int sent)
1631 if (context == SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
1633 && !s->ext.early_data_ok) {
1635 * If we get here then the server accepted our early_data but we
1636 * later realised that it shouldn't have done (e.g. inconsistent
1639 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_FINAL_EARLY_DATA,
1640 SSL_R_BAD_EARLY_DATA);
1647 if (s->max_early_data == 0
1649 || s->session->ext.tick_identity != 0
1650 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING
1651 || !s->ext.early_data_ok
1652 || s->hello_retry_request != SSL_HRR_NONE
1653 || (s->ctx->allow_early_data_cb != NULL
1654 && !s->ctx->allow_early_data_cb(s,
1655 s->ctx->allow_early_data_cb_data))) {
1656 s->ext.early_data = SSL_EARLY_DATA_REJECTED;
1658 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED;
1660 if (!tls13_change_cipher_state(s,
1661 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) {
1662 /* SSLfatal() already called */
1670 static int final_maxfragmentlen(SSL *s, unsigned int context, int sent)
1673 * Session resumption on server-side with MFL extension active
1674 * BUT MFL extension packet was not resent (i.e. sent == 0)
1676 if (s->server && s->hit && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
1678 SSLfatal(s, SSL_AD_MISSING_EXTENSION, SSL_F_FINAL_MAXFRAGMENTLEN,
1679 SSL_R_BAD_EXTENSION);
1683 /* Current SSL buffer is lower than requested MFL */
1684 if (s->session && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
1685 && s->max_send_fragment < GET_MAX_FRAGMENT_LENGTH(s->session))
1686 /* trigger a larger buffer reallocation */
1687 if (!ssl3_setup_buffers(s)) {
1688 /* SSLfatal() already called */
1695 static int init_post_handshake_auth(SSL *s, unsigned int context)
1697 s->post_handshake_auth = SSL_PHA_NONE;