2 * Copyright 2016-2018 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
12 #include "internal/cryptlib.h"
13 #include <openssl/evp.h>
14 #include <openssl/kdf.h>
16 #define TLS13_MAX_LABEL_LEN 246
18 /* Always filled with zeros */
19 static const unsigned char default_zeros
[EVP_MAX_MD_SIZE
];
22 * Given a |secret|; a |label| of length |labellen|; and |data| of length
23 * |datalen| (e.g. typically a hash of the handshake messages), derive a new
24 * secret |outlen| bytes long and store it in the location pointed to be |out|.
25 * The |data| value may be zero length. Returns 1 on success 0 on failure.
27 int tls13_hkdf_expand(SSL
*s
, const EVP_MD
*md
, const unsigned char *secret
,
28 const unsigned char *label
, size_t labellen
,
29 const unsigned char *data
, size_t datalen
,
30 unsigned char *out
, size_t outlen
)
32 const unsigned char label_prefix
[] = "tls13 ";
33 EVP_PKEY_CTX
*pctx
= EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF
, NULL
);
38 * 2 bytes for length of whole HkdfLabel + 1 byte for length of combined
39 * prefix and label + bytes for the label itself + bytes for the hash
41 unsigned char hkdflabel
[sizeof(uint16_t) + sizeof(uint8_t) +
42 + sizeof(label_prefix
) + TLS13_MAX_LABEL_LEN
49 hashlen
= EVP_MD_size(md
);
51 if (!WPACKET_init_static_len(&pkt
, hkdflabel
, sizeof(hkdflabel
), 0)
52 || !WPACKET_put_bytes_u16(&pkt
, outlen
)
53 || !WPACKET_start_sub_packet_u8(&pkt
)
54 || !WPACKET_memcpy(&pkt
, label_prefix
, sizeof(label_prefix
) - 1)
55 || !WPACKET_memcpy(&pkt
, label
, labellen
)
56 || !WPACKET_close(&pkt
)
57 || !WPACKET_sub_memcpy_u8(&pkt
, data
, (data
== NULL
) ? 0 : datalen
)
58 || !WPACKET_get_total_written(&pkt
, &hkdflabellen
)
59 || !WPACKET_finish(&pkt
)) {
60 EVP_PKEY_CTX_free(pctx
);
61 WPACKET_cleanup(&pkt
);
62 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_TLS13_HKDF_EXPAND
,
63 ERR_R_INTERNAL_ERROR
);
67 ret
= EVP_PKEY_derive_init(pctx
) <= 0
68 || EVP_PKEY_CTX_hkdf_mode(pctx
, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY
)
70 || EVP_PKEY_CTX_set_hkdf_md(pctx
, md
) <= 0
71 || EVP_PKEY_CTX_set1_hkdf_key(pctx
, secret
, hashlen
) <= 0
72 || EVP_PKEY_CTX_add1_hkdf_info(pctx
, hkdflabel
, hkdflabellen
) <= 0
73 || EVP_PKEY_derive(pctx
, out
, &outlen
) <= 0;
75 EVP_PKEY_CTX_free(pctx
);
78 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_TLS13_HKDF_EXPAND
,
79 ERR_R_INTERNAL_ERROR
);
85 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
86 * success 0 on failure.
88 int tls13_derive_key(SSL
*s
, const EVP_MD
*md
, const unsigned char *secret
,
89 unsigned char *key
, size_t keylen
)
91 static const unsigned char keylabel
[] = "key";
93 return tls13_hkdf_expand(s
, md
, secret
, keylabel
, sizeof(keylabel
) - 1,
94 NULL
, 0, key
, keylen
);
98 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
99 * success 0 on failure.
101 int tls13_derive_iv(SSL
*s
, const EVP_MD
*md
, const unsigned char *secret
,
102 unsigned char *iv
, size_t ivlen
)
104 static const unsigned char ivlabel
[] = "iv";
106 return tls13_hkdf_expand(s
, md
, secret
, ivlabel
, sizeof(ivlabel
) - 1,
110 int tls13_derive_finishedkey(SSL
*s
, const EVP_MD
*md
,
111 const unsigned char *secret
,
112 unsigned char *fin
, size_t finlen
)
114 static const unsigned char finishedlabel
[] = "finished";
116 return tls13_hkdf_expand(s
, md
, secret
, finishedlabel
,
117 sizeof(finishedlabel
) - 1, NULL
, 0, fin
, finlen
);
121 * Given the previous secret |prevsecret| and a new input secret |insecret| of
122 * length |insecretlen|, generate a new secret and store it in the location
123 * pointed to by |outsecret|. Returns 1 on success 0 on failure.
125 int tls13_generate_secret(SSL
*s
, const EVP_MD
*md
,
126 const unsigned char *prevsecret
,
127 const unsigned char *insecret
,
129 unsigned char *outsecret
)
131 size_t mdlen
, prevsecretlen
;
133 EVP_PKEY_CTX
*pctx
= EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF
, NULL
);
134 static const char derived_secret_label
[] = "derived";
135 unsigned char preextractsec
[EVP_MAX_MD_SIZE
];
138 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_TLS13_GENERATE_SECRET
,
139 ERR_R_INTERNAL_ERROR
);
143 mdlen
= EVP_MD_size(md
);
145 if (insecret
== NULL
) {
146 insecret
= default_zeros
;
149 if (prevsecret
== NULL
) {
150 prevsecret
= default_zeros
;
153 EVP_MD_CTX
*mctx
= EVP_MD_CTX_new();
154 unsigned char hash
[EVP_MAX_MD_SIZE
];
156 /* The pre-extract derive step uses a hash of no messages */
158 || EVP_DigestInit_ex(mctx
, md
, NULL
) <= 0
159 || EVP_DigestFinal_ex(mctx
, hash
, NULL
) <= 0) {
160 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_TLS13_GENERATE_SECRET
,
161 ERR_R_INTERNAL_ERROR
);
162 EVP_MD_CTX_free(mctx
);
163 EVP_PKEY_CTX_free(pctx
);
166 EVP_MD_CTX_free(mctx
);
168 /* Generate the pre-extract secret */
169 if (!tls13_hkdf_expand(s
, md
, prevsecret
,
170 (unsigned char *)derived_secret_label
,
171 sizeof(derived_secret_label
) - 1, hash
, mdlen
,
172 preextractsec
, mdlen
)) {
173 /* SSLfatal() already called */
174 EVP_PKEY_CTX_free(pctx
);
178 prevsecret
= preextractsec
;
179 prevsecretlen
= mdlen
;
182 ret
= EVP_PKEY_derive_init(pctx
) <= 0
183 || EVP_PKEY_CTX_hkdf_mode(pctx
, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY
)
185 || EVP_PKEY_CTX_set_hkdf_md(pctx
, md
) <= 0
186 || EVP_PKEY_CTX_set1_hkdf_key(pctx
, insecret
, insecretlen
) <= 0
187 || EVP_PKEY_CTX_set1_hkdf_salt(pctx
, prevsecret
, prevsecretlen
)
189 || EVP_PKEY_derive(pctx
, outsecret
, &mdlen
)
193 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_TLS13_GENERATE_SECRET
,
194 ERR_R_INTERNAL_ERROR
);
196 EVP_PKEY_CTX_free(pctx
);
197 if (prevsecret
== preextractsec
)
198 OPENSSL_cleanse(preextractsec
, mdlen
);
203 * Given an input secret |insecret| of length |insecretlen| generate the
204 * handshake secret. This requires the early secret to already have been
205 * generated. Returns 1 on success 0 on failure.
207 int tls13_generate_handshake_secret(SSL
*s
, const unsigned char *insecret
,
210 /* Calls SSLfatal() if required */
211 return tls13_generate_secret(s
, ssl_handshake_md(s
), s
->early_secret
,
212 insecret
, insecretlen
,
213 (unsigned char *)&s
->handshake_secret
);
217 * Given the handshake secret |prev| of length |prevlen| generate the master
218 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
221 int tls13_generate_master_secret(SSL
*s
, unsigned char *out
,
222 unsigned char *prev
, size_t prevlen
,
225 const EVP_MD
*md
= ssl_handshake_md(s
);
227 *secret_size
= EVP_MD_size(md
);
228 /* Calls SSLfatal() if required */
229 return tls13_generate_secret(s
, md
, prev
, NULL
, 0, out
);
233 * Generates the mac for the Finished message. Returns the length of the MAC or
236 size_t tls13_final_finish_mac(SSL
*s
, const char *str
, size_t slen
,
239 const EVP_MD
*md
= ssl_handshake_md(s
);
240 unsigned char hash
[EVP_MAX_MD_SIZE
];
241 size_t hashlen
, ret
= 0;
242 EVP_PKEY
*key
= NULL
;
243 EVP_MD_CTX
*ctx
= EVP_MD_CTX_new();
245 if (!ssl_handshake_hash(s
, hash
, sizeof(hash
), &hashlen
)) {
246 /* SSLfatal() already called */
250 if (str
== s
->method
->ssl3_enc
->server_finished_label
)
251 key
= EVP_PKEY_new_mac_key(EVP_PKEY_HMAC
, NULL
,
252 s
->server_finished_secret
, hashlen
);
254 key
= EVP_PKEY_new_mac_key(EVP_PKEY_HMAC
, NULL
,
255 s
->client_finished_secret
, hashlen
);
259 || EVP_DigestSignInit(ctx
, NULL
, md
, NULL
, key
) <= 0
260 || EVP_DigestSignUpdate(ctx
, hash
, hashlen
) <= 0
261 || EVP_DigestSignFinal(ctx
, out
, &hashlen
) <= 0) {
262 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_TLS13_FINAL_FINISH_MAC
,
263 ERR_R_INTERNAL_ERROR
);
270 EVP_MD_CTX_free(ctx
);
275 * There isn't really a key block in TLSv1.3, but we still need this function
276 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
278 int tls13_setup_key_block(SSL
*s
)
282 int mac_type
= NID_undef
;
284 s
->session
->cipher
= s
->s3
->tmp
.new_cipher
;
285 if (!ssl_cipher_get_evp
286 (s
->session
, &c
, &hash
, &mac_type
, NULL
, NULL
, 0)) {
287 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_TLS13_SETUP_KEY_BLOCK
,
288 SSL_R_CIPHER_OR_HASH_UNAVAILABLE
);
292 s
->s3
->tmp
.new_sym_enc
= c
;
293 s
->s3
->tmp
.new_hash
= hash
;
298 static int derive_secret_key_and_iv(SSL
*s
, int sending
, const EVP_MD
*md
,
299 const EVP_CIPHER
*ciph
,
300 const unsigned char *insecret
,
301 const unsigned char *hash
,
302 const unsigned char *label
,
303 size_t labellen
, unsigned char *secret
,
304 unsigned char *iv
, EVP_CIPHER_CTX
*ciph_ctx
)
306 unsigned char key
[EVP_MAX_KEY_LENGTH
];
307 size_t ivlen
, keylen
, taglen
;
308 size_t hashlen
= EVP_MD_size(md
);
310 if (!tls13_hkdf_expand(s
, md
, insecret
, label
, labellen
, hash
, hashlen
,
312 /* SSLfatal() already called */
316 /* TODO(size_t): convert me */
317 keylen
= EVP_CIPHER_key_length(ciph
);
318 if (EVP_CIPHER_mode(ciph
) == EVP_CIPH_CCM_MODE
) {
321 ivlen
= EVP_CCM_TLS_IV_LEN
;
322 if (s
->s3
->tmp
.new_cipher
== NULL
) {
323 /* We've not selected a cipher yet - we must be doing early data */
324 algenc
= s
->session
->cipher
->algorithm_enc
;
326 algenc
= s
->s3
->tmp
.new_cipher
->algorithm_enc
;
328 if (algenc
& (SSL_AES128CCM8
| SSL_AES256CCM8
))
329 taglen
= EVP_CCM8_TLS_TAG_LEN
;
331 taglen
= EVP_CCM_TLS_TAG_LEN
;
333 ivlen
= EVP_CIPHER_iv_length(ciph
);
337 if (!tls13_derive_key(s
, md
, secret
, key
, keylen
)
338 || !tls13_derive_iv(s
, md
, secret
, iv
, ivlen
)) {
339 /* SSLfatal() already called */
343 if (EVP_CipherInit_ex(ciph_ctx
, ciph
, NULL
, NULL
, NULL
, sending
) <= 0
344 || !EVP_CIPHER_CTX_ctrl(ciph_ctx
, EVP_CTRL_AEAD_SET_IVLEN
, ivlen
, NULL
)
345 || (taglen
!= 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx
, EVP_CTRL_AEAD_SET_TAG
,
347 || EVP_CipherInit_ex(ciph_ctx
, NULL
, NULL
, key
, NULL
, -1) <= 0) {
348 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_DERIVE_SECRET_KEY_AND_IV
,
355 OPENSSL_cleanse(key
, sizeof(key
));
359 int tls13_change_cipher_state(SSL
*s
, int which
)
361 static const unsigned char client_early_traffic
[] = "c e traffic";
362 static const unsigned char client_handshake_traffic
[] = "c hs traffic";
363 static const unsigned char client_application_traffic
[] = "c ap traffic";
364 static const unsigned char server_handshake_traffic
[] = "s hs traffic";
365 static const unsigned char server_application_traffic
[] = "s ap traffic";
366 static const unsigned char exporter_master_secret
[] = "exp master";
367 static const unsigned char resumption_master_secret
[] = "res master";
368 static const unsigned char early_exporter_master_secret
[] = "e exp master";
370 unsigned char secret
[EVP_MAX_MD_SIZE
];
371 unsigned char hashval
[EVP_MAX_MD_SIZE
];
372 unsigned char *hash
= hashval
;
373 unsigned char *insecret
;
374 unsigned char *finsecret
= NULL
;
375 const char *log_label
= NULL
;
376 EVP_CIPHER_CTX
*ciph_ctx
;
377 size_t finsecretlen
= 0;
378 const unsigned char *label
;
379 size_t labellen
, hashlen
= 0;
381 const EVP_MD
*md
= NULL
;
382 const EVP_CIPHER
*cipher
= NULL
;
384 if (which
& SSL3_CC_READ
) {
385 if (s
->enc_read_ctx
!= NULL
) {
386 EVP_CIPHER_CTX_reset(s
->enc_read_ctx
);
388 s
->enc_read_ctx
= EVP_CIPHER_CTX_new();
389 if (s
->enc_read_ctx
== NULL
) {
390 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
391 SSL_F_TLS13_CHANGE_CIPHER_STATE
, ERR_R_MALLOC_FAILURE
);
395 ciph_ctx
= s
->enc_read_ctx
;
398 RECORD_LAYER_reset_read_sequence(&s
->rlayer
);
400 if (s
->enc_write_ctx
!= NULL
) {
401 EVP_CIPHER_CTX_reset(s
->enc_write_ctx
);
403 s
->enc_write_ctx
= EVP_CIPHER_CTX_new();
404 if (s
->enc_write_ctx
== NULL
) {
405 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
406 SSL_F_TLS13_CHANGE_CIPHER_STATE
, ERR_R_MALLOC_FAILURE
);
410 ciph_ctx
= s
->enc_write_ctx
;
413 RECORD_LAYER_reset_write_sequence(&s
->rlayer
);
416 if (((which
& SSL3_CC_CLIENT
) && (which
& SSL3_CC_WRITE
))
417 || ((which
& SSL3_CC_SERVER
) && (which
& SSL3_CC_READ
))) {
418 if (which
& SSL3_CC_EARLY
) {
419 EVP_MD_CTX
*mdctx
= NULL
;
422 unsigned int hashlenui
;
423 const SSL_CIPHER
*sslcipher
= SSL_SESSION_get0_cipher(s
->session
);
425 insecret
= s
->early_secret
;
426 label
= client_early_traffic
;
427 labellen
= sizeof(client_early_traffic
) - 1;
428 log_label
= CLIENT_EARLY_LABEL
;
430 handlen
= BIO_get_mem_data(s
->s3
->handshake_buffer
, &hdata
);
432 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
433 SSL_F_TLS13_CHANGE_CIPHER_STATE
,
434 SSL_R_BAD_HANDSHAKE_LENGTH
);
438 if (s
->early_data_state
== SSL_EARLY_DATA_CONNECTING
439 && s
->max_early_data
> 0
440 && s
->session
->ext
.max_early_data
== 0) {
442 * If we are attempting to send early data, and we've decided to
443 * actually do it but max_early_data in s->session is 0 then we
444 * must be using an external PSK.
446 if (!ossl_assert(s
->psksession
!= NULL
447 && s
->max_early_data
==
448 s
->psksession
->ext
.max_early_data
)) {
449 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
450 SSL_F_TLS13_CHANGE_CIPHER_STATE
,
451 ERR_R_INTERNAL_ERROR
);
454 sslcipher
= SSL_SESSION_get0_cipher(s
->psksession
);
456 if (sslcipher
== NULL
) {
457 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
458 SSL_F_TLS13_CHANGE_CIPHER_STATE
, SSL_R_BAD_PSK
);
463 * We need to calculate the handshake digest using the digest from
464 * the session. We haven't yet selected our ciphersuite so we can't
465 * use ssl_handshake_md().
467 mdctx
= EVP_MD_CTX_new();
469 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
470 SSL_F_TLS13_CHANGE_CIPHER_STATE
, ERR_R_MALLOC_FAILURE
);
473 cipher
= EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher
));
474 md
= ssl_md(sslcipher
->algorithm2
);
475 if (md
== NULL
|| !EVP_DigestInit_ex(mdctx
, md
, NULL
)
476 || !EVP_DigestUpdate(mdctx
, hdata
, handlen
)
477 || !EVP_DigestFinal_ex(mdctx
, hashval
, &hashlenui
)) {
478 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
479 SSL_F_TLS13_CHANGE_CIPHER_STATE
, ERR_R_INTERNAL_ERROR
);
480 EVP_MD_CTX_free(mdctx
);
484 EVP_MD_CTX_free(mdctx
);
486 if (!tls13_hkdf_expand(s
, md
, insecret
,
487 early_exporter_master_secret
,
488 sizeof(early_exporter_master_secret
) - 1,
490 s
->early_exporter_master_secret
, hashlen
)) {
491 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
492 SSL_F_TLS13_CHANGE_CIPHER_STATE
, ERR_R_INTERNAL_ERROR
);
495 } else if (which
& SSL3_CC_HANDSHAKE
) {
496 insecret
= s
->handshake_secret
;
497 finsecret
= s
->client_finished_secret
;
498 finsecretlen
= EVP_MD_size(ssl_handshake_md(s
));
499 label
= client_handshake_traffic
;
500 labellen
= sizeof(client_handshake_traffic
) - 1;
501 log_label
= CLIENT_HANDSHAKE_LABEL
;
503 * The handshake hash used for the server read/client write handshake
504 * traffic secret is the same as the hash for the server
505 * write/client read handshake traffic secret. However, if we
506 * processed early data then we delay changing the server
507 * read/client write cipher state until later, and the handshake
508 * hashes have moved on. Therefore we use the value saved earlier
509 * when we did the server write/client read change cipher state.
511 hash
= s
->handshake_traffic_hash
;
513 insecret
= s
->master_secret
;
514 label
= client_application_traffic
;
515 labellen
= sizeof(client_application_traffic
) - 1;
516 log_label
= CLIENT_APPLICATION_LABEL
;
518 * For this we only use the handshake hashes up until the server
519 * Finished hash. We do not include the client's Finished, which is
520 * what ssl_handshake_hash() would give us. Instead we use the
521 * previously saved value.
523 hash
= s
->server_finished_hash
;
526 /* Early data never applies to client-read/server-write */
527 if (which
& SSL3_CC_HANDSHAKE
) {
528 insecret
= s
->handshake_secret
;
529 finsecret
= s
->server_finished_secret
;
530 finsecretlen
= EVP_MD_size(ssl_handshake_md(s
));
531 label
= server_handshake_traffic
;
532 labellen
= sizeof(server_handshake_traffic
) - 1;
533 log_label
= SERVER_HANDSHAKE_LABEL
;
535 insecret
= s
->master_secret
;
536 label
= server_application_traffic
;
537 labellen
= sizeof(server_application_traffic
) - 1;
538 log_label
= SERVER_APPLICATION_LABEL
;
542 if (!(which
& SSL3_CC_EARLY
)) {
543 md
= ssl_handshake_md(s
);
544 cipher
= s
->s3
->tmp
.new_sym_enc
;
545 if (!ssl3_digest_cached_records(s
, 1)
546 || !ssl_handshake_hash(s
, hashval
, sizeof(hashval
), &hashlen
)) {
547 /* SSLfatal() already called */;
553 * Save the hash of handshakes up to now for use when we calculate the
554 * client application traffic secret
556 if (label
== server_application_traffic
)
557 memcpy(s
->server_finished_hash
, hashval
, hashlen
);
559 if (label
== server_handshake_traffic
)
560 memcpy(s
->handshake_traffic_hash
, hashval
, hashlen
);
562 if (label
== client_application_traffic
) {
564 * We also create the resumption master secret, but this time use the
565 * hash for the whole handshake including the Client Finished
567 if (!tls13_hkdf_expand(s
, ssl_handshake_md(s
), insecret
,
568 resumption_master_secret
,
569 sizeof(resumption_master_secret
) - 1,
570 hashval
, hashlen
, s
->session
->master_key
,
572 /* SSLfatal() already called */
575 s
->session
->master_key_length
= hashlen
;
578 if (!derive_secret_key_and_iv(s
, which
& SSL3_CC_WRITE
, md
, cipher
,
579 insecret
, hash
, label
, labellen
, secret
, iv
,
581 /* SSLfatal() already called */
585 if (label
== server_application_traffic
) {
586 memcpy(s
->server_app_traffic_secret
, secret
, hashlen
);
587 /* Now we create the exporter master secret */
588 if (!tls13_hkdf_expand(s
, ssl_handshake_md(s
), insecret
,
589 exporter_master_secret
,
590 sizeof(exporter_master_secret
) - 1,
591 hash
, hashlen
, s
->exporter_master_secret
,
593 /* SSLfatal() already called */
596 } else if (label
== client_application_traffic
)
597 memcpy(s
->client_app_traffic_secret
, secret
, hashlen
);
599 if (!ssl_log_secret(s
, log_label
, secret
, hashlen
)) {
600 /* SSLfatal() already called */
604 if (finsecret
!= NULL
605 && !tls13_derive_finishedkey(s
, ssl_handshake_md(s
), secret
,
606 finsecret
, finsecretlen
)) {
607 /* SSLfatal() already called */
613 OPENSSL_cleanse(secret
, sizeof(secret
));
617 int tls13_update_key(SSL
*s
, int sending
)
619 static const unsigned char application_traffic
[] = "traffic upd";
620 const EVP_MD
*md
= ssl_handshake_md(s
);
621 size_t hashlen
= EVP_MD_size(md
);
622 unsigned char *insecret
, *iv
;
623 unsigned char secret
[EVP_MAX_MD_SIZE
];
624 EVP_CIPHER_CTX
*ciph_ctx
;
627 if (s
->server
== sending
)
628 insecret
= s
->server_app_traffic_secret
;
630 insecret
= s
->client_app_traffic_secret
;
634 ciph_ctx
= s
->enc_write_ctx
;
635 RECORD_LAYER_reset_write_sequence(&s
->rlayer
);
638 ciph_ctx
= s
->enc_read_ctx
;
639 RECORD_LAYER_reset_read_sequence(&s
->rlayer
);
642 if (!derive_secret_key_and_iv(s
, sending
, ssl_handshake_md(s
),
643 s
->s3
->tmp
.new_sym_enc
, insecret
, NULL
,
645 sizeof(application_traffic
) - 1, secret
, iv
,
647 /* SSLfatal() already called */
651 memcpy(insecret
, secret
, hashlen
);
655 OPENSSL_cleanse(secret
, sizeof(secret
));
659 int tls13_alert_code(int code
)
661 if (code
== SSL_AD_MISSING_EXTENSION
)
664 return tls1_alert_code(code
);
667 int tls13_export_keying_material(SSL
*s
, unsigned char *out
, size_t olen
,
668 const char *label
, size_t llen
,
669 const unsigned char *context
,
670 size_t contextlen
, int use_context
)
672 unsigned char exportsecret
[EVP_MAX_MD_SIZE
];
673 static const unsigned char exporterlabel
[] = "exporter";
674 unsigned char hash
[EVP_MAX_MD_SIZE
], data
[EVP_MAX_MD_SIZE
];
675 const EVP_MD
*md
= ssl_handshake_md(s
);
676 EVP_MD_CTX
*ctx
= EVP_MD_CTX_new();
677 unsigned int hashsize
, datalen
;
680 if (ctx
== NULL
|| !ossl_statem_export_allowed(s
))
686 if (EVP_DigestInit_ex(ctx
, md
, NULL
) <= 0
687 || EVP_DigestUpdate(ctx
, context
, contextlen
) <= 0
688 || EVP_DigestFinal_ex(ctx
, hash
, &hashsize
) <= 0
689 || EVP_DigestInit_ex(ctx
, md
, NULL
) <= 0
690 || EVP_DigestFinal_ex(ctx
, data
, &datalen
) <= 0
691 || !tls13_hkdf_expand(s
, md
, s
->exporter_master_secret
,
692 (const unsigned char *)label
, llen
,
693 data
, datalen
, exportsecret
, hashsize
)
694 || !tls13_hkdf_expand(s
, md
, exportsecret
, exporterlabel
,
695 sizeof(exporterlabel
) - 1, hash
, hashsize
,
701 EVP_MD_CTX_free(ctx
);
705 int tls13_export_keying_material_early(SSL
*s
, unsigned char *out
, size_t olen
,
706 const char *label
, size_t llen
,
707 const unsigned char *context
,
710 static const unsigned char exporterlabel
[] = "exporter";
711 unsigned char exportsecret
[EVP_MAX_MD_SIZE
];
712 unsigned char hash
[EVP_MAX_MD_SIZE
], data
[EVP_MAX_MD_SIZE
];
714 EVP_MD_CTX
*ctx
= EVP_MD_CTX_new();
715 unsigned int hashsize
, datalen
;
717 const SSL_CIPHER
*sslcipher
;
719 if (ctx
== NULL
|| !ossl_statem_export_early_allowed(s
))
722 if (!s
->server
&& s
->max_early_data
> 0
723 && s
->session
->ext
.max_early_data
== 0)
724 sslcipher
= SSL_SESSION_get0_cipher(s
->psksession
);
726 sslcipher
= SSL_SESSION_get0_cipher(s
->session
);
728 md
= ssl_md(sslcipher
->algorithm2
);
731 * Calculate the hash value and store it in |data|. The reason why
732 * the empty string is used is that the definition of TLS-Exporter
735 * TLS-Exporter(label, context_value, key_length) =
736 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
737 * "exporter", Hash(context_value), key_length)
739 * Derive-Secret(Secret, Label, Messages) =
740 * HKDF-Expand-Label(Secret, Label,
741 * Transcript-Hash(Messages), Hash.length)
743 * Here Transcript-Hash is the cipher suite hash algorithm.
745 if (EVP_DigestInit_ex(ctx
, md
, NULL
) <= 0
746 || EVP_DigestUpdate(ctx
, context
, contextlen
) <= 0
747 || EVP_DigestFinal_ex(ctx
, hash
, &hashsize
) <= 0
748 || EVP_DigestInit_ex(ctx
, md
, NULL
) <= 0
749 || EVP_DigestFinal_ex(ctx
, data
, &datalen
) <= 0
750 || !tls13_hkdf_expand(s
, md
, s
->early_exporter_master_secret
,
751 (const unsigned char *)label
, llen
,
752 data
, datalen
, exportsecret
, hashsize
)
753 || !tls13_hkdf_expand(s
, md
, exportsecret
, exporterlabel
,
754 sizeof(exporterlabel
) - 1, hash
, hashsize
,
760 EVP_MD_CTX_free(ctx
);