2 * Copyright 2016-2018 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
12 #include "internal/cryptlib.h"
13 #include <openssl/evp.h>
14 #include <openssl/kdf.h>
16 #define TLS13_MAX_LABEL_LEN 249
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. Any errors will be treated as fatal if
26 * |fatal| is set. Returns 1 on success 0 on failure.
28 int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
29 const unsigned char *label, size_t labellen,
30 const unsigned char *data, size_t datalen,
31 unsigned char *out, size_t outlen, int fatal)
33 static const unsigned char label_prefix[] = "tls13 ";
34 EVP_KDF_CTX *kctx = EVP_KDF_CTX_new_id(EVP_PKEY_HKDF);
39 * 2 bytes for length of derived secret + 1 byte for length of combined
40 * prefix and label + bytes for the label itself + 1 byte length of hash
41 * + bytes for the hash itself
43 unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) +
44 + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN
45 + 1 + EVP_MAX_MD_SIZE];
51 if (labellen > TLS13_MAX_LABEL_LEN) {
53 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
54 ERR_R_INTERNAL_ERROR);
57 * Probably we have been called from SSL_export_keying_material(),
58 * or SSL_export_keying_material_early().
60 SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
62 EVP_KDF_CTX_free(kctx);
66 hashlen = EVP_MD_size(md);
68 if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
69 || !WPACKET_put_bytes_u16(&pkt, outlen)
70 || !WPACKET_start_sub_packet_u8(&pkt)
71 || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
72 || !WPACKET_memcpy(&pkt, label, labellen)
73 || !WPACKET_close(&pkt)
74 || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
75 || !WPACKET_get_total_written(&pkt, &hkdflabellen)
76 || !WPACKET_finish(&pkt)) {
77 EVP_KDF_CTX_free(kctx);
78 WPACKET_cleanup(&pkt);
80 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
81 ERR_R_INTERNAL_ERROR);
83 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
87 ret = EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_HKDF_MODE,
88 EVP_PKEY_HKDEF_MODE_EXPAND_ONLY) <= 0
89 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_MD, md) <= 0
90 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_KEY, secret, hashlen) <= 0
91 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_ADD_HKDF_INFO,
92 hkdflabel, hkdflabellen) <= 0
93 || EVP_KDF_derive(kctx, out, outlen) <= 0;
95 EVP_KDF_CTX_free(kctx);
99 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
100 ERR_R_INTERNAL_ERROR);
102 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
109 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
110 * success 0 on failure.
112 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
113 unsigned char *key, size_t keylen)
115 static const unsigned char keylabel[] = "key";
117 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
118 NULL, 0, key, keylen, 1);
122 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
123 * success 0 on failure.
125 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
126 unsigned char *iv, size_t ivlen)
128 static const unsigned char ivlabel[] = "iv";
130 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
131 NULL, 0, iv, ivlen, 1);
134 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
135 const unsigned char *secret,
136 unsigned char *fin, size_t finlen)
138 static const unsigned char finishedlabel[] = "finished";
140 return tls13_hkdf_expand(s, md, secret, finishedlabel,
141 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
145 * Given the previous secret |prevsecret| and a new input secret |insecret| of
146 * length |insecretlen|, generate a new secret and store it in the location
147 * pointed to by |outsecret|. Returns 1 on success 0 on failure.
149 int tls13_generate_secret(SSL *s, const EVP_MD *md,
150 const unsigned char *prevsecret,
151 const unsigned char *insecret,
153 unsigned char *outsecret)
155 size_t mdlen, prevsecretlen;
158 EVP_KDF_CTX *kctx = EVP_KDF_CTX_new_id(EVP_PKEY_HKDF);
159 static const char derived_secret_label[] = "derived";
160 unsigned char preextractsec[EVP_MAX_MD_SIZE];
163 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
164 ERR_R_INTERNAL_ERROR);
168 mdleni = EVP_MD_size(md);
169 /* Ensure cast to size_t is safe */
170 if (!ossl_assert(mdleni >= 0)) {
171 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
172 ERR_R_INTERNAL_ERROR);
175 mdlen = (size_t)mdleni;
177 if (insecret == NULL) {
178 insecret = default_zeros;
181 if (prevsecret == NULL) {
182 prevsecret = default_zeros;
185 EVP_MD_CTX *mctx = EVP_MD_CTX_new();
186 unsigned char hash[EVP_MAX_MD_SIZE];
188 /* The pre-extract derive step uses a hash of no messages */
190 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
191 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
192 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
193 ERR_R_INTERNAL_ERROR);
194 EVP_MD_CTX_free(mctx);
195 EVP_KDF_CTX_free(kctx);
198 EVP_MD_CTX_free(mctx);
200 /* Generate the pre-extract secret */
201 if (!tls13_hkdf_expand(s, md, prevsecret,
202 (unsigned char *)derived_secret_label,
203 sizeof(derived_secret_label) - 1, hash, mdlen,
204 preextractsec, mdlen, 1)) {
205 /* SSLfatal() already called */
206 EVP_KDF_CTX_free(kctx);
210 prevsecret = preextractsec;
211 prevsecretlen = mdlen;
214 ret = EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_HKDF_MODE,
215 EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) <= 0
216 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_MD, md) <= 0
217 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_KEY, insecret, insecretlen) <= 0
218 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_SALT,
219 prevsecret, prevsecretlen) <= 0
220 || EVP_KDF_derive(kctx, outsecret, mdlen) <= 0;
223 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
224 ERR_R_INTERNAL_ERROR);
226 EVP_KDF_CTX_free(kctx);
227 if (prevsecret == preextractsec)
228 OPENSSL_cleanse(preextractsec, mdlen);
233 * Given an input secret |insecret| of length |insecretlen| generate the
234 * handshake secret. This requires the early secret to already have been
235 * generated. Returns 1 on success 0 on failure.
237 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
240 /* Calls SSLfatal() if required */
241 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
242 insecret, insecretlen,
243 (unsigned char *)&s->handshake_secret);
247 * Given the handshake secret |prev| of length |prevlen| generate the master
248 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
251 int tls13_generate_master_secret(SSL *s, unsigned char *out,
252 unsigned char *prev, size_t prevlen,
255 const EVP_MD *md = ssl_handshake_md(s);
257 *secret_size = EVP_MD_size(md);
258 /* Calls SSLfatal() if required */
259 return tls13_generate_secret(s, md, prev, NULL, 0, out);
263 * Generates the mac for the Finished message. Returns the length of the MAC or
266 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
269 const EVP_MD *md = ssl_handshake_md(s);
270 unsigned char hash[EVP_MAX_MD_SIZE];
271 size_t hashlen, ret = 0;
272 EVP_PKEY *key = NULL;
273 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
275 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
276 /* SSLfatal() already called */
280 if (str == s->method->ssl3_enc->server_finished_label) {
281 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
282 s->server_finished_secret, hashlen);
283 } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
284 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
285 s->client_finished_secret, hashlen);
287 unsigned char finsecret[EVP_MAX_MD_SIZE];
289 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
290 s->client_app_traffic_secret,
294 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret,
296 OPENSSL_cleanse(finsecret, sizeof(finsecret));
301 || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0
302 || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0
303 || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) {
304 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
305 ERR_R_INTERNAL_ERROR);
312 EVP_MD_CTX_free(ctx);
317 * There isn't really a key block in TLSv1.3, but we still need this function
318 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
320 int tls13_setup_key_block(SSL *s)
325 s->session->cipher = s->s3.tmp.new_cipher;
326 if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) {
327 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK,
328 SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
332 s->s3.tmp.new_sym_enc = c;
333 s->s3.tmp.new_hash = hash;
338 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
339 const EVP_CIPHER *ciph,
340 const unsigned char *insecret,
341 const unsigned char *hash,
342 const unsigned char *label,
343 size_t labellen, unsigned char *secret,
344 unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx)
346 unsigned char key[EVP_MAX_KEY_LENGTH];
347 size_t ivlen, keylen, taglen;
348 int hashleni = EVP_MD_size(md);
351 /* Ensure cast to size_t is safe */
352 if (!ossl_assert(hashleni >= 0)) {
353 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
357 hashlen = (size_t)hashleni;
359 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
360 secret, hashlen, 1)) {
361 /* SSLfatal() already called */
365 /* TODO(size_t): convert me */
366 keylen = EVP_CIPHER_key_length(ciph);
367 if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
370 ivlen = EVP_CCM_TLS_IV_LEN;
371 if (s->s3.tmp.new_cipher == NULL) {
372 /* We've not selected a cipher yet - we must be doing early data */
373 algenc = s->session->cipher->algorithm_enc;
375 algenc = s->s3.tmp.new_cipher->algorithm_enc;
377 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
378 taglen = EVP_CCM8_TLS_TAG_LEN;
380 taglen = EVP_CCM_TLS_TAG_LEN;
382 ivlen = EVP_CIPHER_iv_length(ciph);
386 if (!tls13_derive_key(s, md, secret, key, keylen)
387 || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
388 /* SSLfatal() already called */
392 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
393 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
394 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
396 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
397 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
404 OPENSSL_cleanse(key, sizeof(key));
408 int tls13_change_cipher_state(SSL *s, int which)
410 static const unsigned char client_early_traffic[] = "c e traffic";
411 static const unsigned char client_handshake_traffic[] = "c hs traffic";
412 static const unsigned char client_application_traffic[] = "c ap traffic";
413 static const unsigned char server_handshake_traffic[] = "s hs traffic";
414 static const unsigned char server_application_traffic[] = "s ap traffic";
415 static const unsigned char exporter_master_secret[] = "exp master";
416 static const unsigned char resumption_master_secret[] = "res master";
417 static const unsigned char early_exporter_master_secret[] = "e exp master";
419 unsigned char secret[EVP_MAX_MD_SIZE];
420 unsigned char hashval[EVP_MAX_MD_SIZE];
421 unsigned char *hash = hashval;
422 unsigned char *insecret;
423 unsigned char *finsecret = NULL;
424 const char *log_label = NULL;
425 EVP_CIPHER_CTX *ciph_ctx;
426 size_t finsecretlen = 0;
427 const unsigned char *label;
428 size_t labellen, hashlen = 0;
430 const EVP_MD *md = NULL;
431 const EVP_CIPHER *cipher = NULL;
433 if (which & SSL3_CC_READ) {
434 if (s->enc_read_ctx != NULL) {
435 EVP_CIPHER_CTX_reset(s->enc_read_ctx);
437 s->enc_read_ctx = EVP_CIPHER_CTX_new();
438 if (s->enc_read_ctx == NULL) {
439 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
440 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
444 ciph_ctx = s->enc_read_ctx;
447 RECORD_LAYER_reset_read_sequence(&s->rlayer);
449 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
450 if (s->enc_write_ctx != NULL) {
451 EVP_CIPHER_CTX_reset(s->enc_write_ctx);
453 s->enc_write_ctx = EVP_CIPHER_CTX_new();
454 if (s->enc_write_ctx == NULL) {
455 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
456 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
460 ciph_ctx = s->enc_write_ctx;
463 RECORD_LAYER_reset_write_sequence(&s->rlayer);
466 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
467 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
468 if (which & SSL3_CC_EARLY) {
469 EVP_MD_CTX *mdctx = NULL;
472 unsigned int hashlenui;
473 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
475 insecret = s->early_secret;
476 label = client_early_traffic;
477 labellen = sizeof(client_early_traffic) - 1;
478 log_label = CLIENT_EARLY_LABEL;
480 handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
482 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
483 SSL_F_TLS13_CHANGE_CIPHER_STATE,
484 SSL_R_BAD_HANDSHAKE_LENGTH);
488 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
489 && s->max_early_data > 0
490 && s->session->ext.max_early_data == 0) {
492 * If we are attempting to send early data, and we've decided to
493 * actually do it but max_early_data in s->session is 0 then we
494 * must be using an external PSK.
496 if (!ossl_assert(s->psksession != NULL
497 && s->max_early_data ==
498 s->psksession->ext.max_early_data)) {
499 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
500 SSL_F_TLS13_CHANGE_CIPHER_STATE,
501 ERR_R_INTERNAL_ERROR);
504 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
506 if (sslcipher == NULL) {
507 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
508 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK);
513 * We need to calculate the handshake digest using the digest from
514 * the session. We haven't yet selected our ciphersuite so we can't
515 * use ssl_handshake_md().
517 mdctx = EVP_MD_CTX_new();
519 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
520 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
523 cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher));
524 md = ssl_md(sslcipher->algorithm2);
525 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
526 || !EVP_DigestUpdate(mdctx, hdata, handlen)
527 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
528 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
529 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
530 EVP_MD_CTX_free(mdctx);
534 EVP_MD_CTX_free(mdctx);
536 if (!tls13_hkdf_expand(s, md, insecret,
537 early_exporter_master_secret,
538 sizeof(early_exporter_master_secret) - 1,
540 s->early_exporter_master_secret, hashlen,
542 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
543 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
547 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
548 s->early_exporter_master_secret, hashlen)) {
549 /* SSLfatal() already called */
552 } else if (which & SSL3_CC_HANDSHAKE) {
553 insecret = s->handshake_secret;
554 finsecret = s->client_finished_secret;
555 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
556 label = client_handshake_traffic;
557 labellen = sizeof(client_handshake_traffic) - 1;
558 log_label = CLIENT_HANDSHAKE_LABEL;
560 * The handshake hash used for the server read/client write handshake
561 * traffic secret is the same as the hash for the server
562 * write/client read handshake traffic secret. However, if we
563 * processed early data then we delay changing the server
564 * read/client write cipher state until later, and the handshake
565 * hashes have moved on. Therefore we use the value saved earlier
566 * when we did the server write/client read change cipher state.
568 hash = s->handshake_traffic_hash;
570 insecret = s->master_secret;
571 label = client_application_traffic;
572 labellen = sizeof(client_application_traffic) - 1;
573 log_label = CLIENT_APPLICATION_LABEL;
575 * For this we only use the handshake hashes up until the server
576 * Finished hash. We do not include the client's Finished, which is
577 * what ssl_handshake_hash() would give us. Instead we use the
578 * previously saved value.
580 hash = s->server_finished_hash;
583 /* Early data never applies to client-read/server-write */
584 if (which & SSL3_CC_HANDSHAKE) {
585 insecret = s->handshake_secret;
586 finsecret = s->server_finished_secret;
587 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
588 label = server_handshake_traffic;
589 labellen = sizeof(server_handshake_traffic) - 1;
590 log_label = SERVER_HANDSHAKE_LABEL;
592 insecret = s->master_secret;
593 label = server_application_traffic;
594 labellen = sizeof(server_application_traffic) - 1;
595 log_label = SERVER_APPLICATION_LABEL;
599 if (!(which & SSL3_CC_EARLY)) {
600 md = ssl_handshake_md(s);
601 cipher = s->s3.tmp.new_sym_enc;
602 if (!ssl3_digest_cached_records(s, 1)
603 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
604 /* SSLfatal() already called */;
610 * Save the hash of handshakes up to now for use when we calculate the
611 * client application traffic secret
613 if (label == server_application_traffic)
614 memcpy(s->server_finished_hash, hashval, hashlen);
616 if (label == server_handshake_traffic)
617 memcpy(s->handshake_traffic_hash, hashval, hashlen);
619 if (label == client_application_traffic) {
621 * We also create the resumption master secret, but this time use the
622 * hash for the whole handshake including the Client Finished
624 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
625 resumption_master_secret,
626 sizeof(resumption_master_secret) - 1,
627 hashval, hashlen, s->resumption_master_secret,
629 /* SSLfatal() already called */
634 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
635 insecret, hash, label, labellen, secret, iv,
637 /* SSLfatal() already called */
641 if (label == server_application_traffic) {
642 memcpy(s->server_app_traffic_secret, secret, hashlen);
643 /* Now we create the exporter master secret */
644 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
645 exporter_master_secret,
646 sizeof(exporter_master_secret) - 1,
647 hash, hashlen, s->exporter_master_secret,
649 /* SSLfatal() already called */
653 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
655 /* SSLfatal() already called */
658 } else if (label == client_application_traffic)
659 memcpy(s->client_app_traffic_secret, secret, hashlen);
661 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
662 /* SSLfatal() already called */
666 if (finsecret != NULL
667 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
668 finsecret, finsecretlen)) {
669 /* SSLfatal() already called */
673 if (!s->server && label == client_early_traffic)
674 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
676 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
679 OPENSSL_cleanse(secret, sizeof(secret));
683 int tls13_update_key(SSL *s, int sending)
685 static const unsigned char application_traffic[] = "traffic upd";
686 const EVP_MD *md = ssl_handshake_md(s);
687 size_t hashlen = EVP_MD_size(md);
688 unsigned char *insecret, *iv;
689 unsigned char secret[EVP_MAX_MD_SIZE];
690 EVP_CIPHER_CTX *ciph_ctx;
693 if (s->server == sending)
694 insecret = s->server_app_traffic_secret;
696 insecret = s->client_app_traffic_secret;
699 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
701 ciph_ctx = s->enc_write_ctx;
702 RECORD_LAYER_reset_write_sequence(&s->rlayer);
705 ciph_ctx = s->enc_read_ctx;
706 RECORD_LAYER_reset_read_sequence(&s->rlayer);
709 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
710 s->s3.tmp.new_sym_enc, insecret, NULL,
712 sizeof(application_traffic) - 1, secret, iv,
714 /* SSLfatal() already called */
718 memcpy(insecret, secret, hashlen);
720 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
723 OPENSSL_cleanse(secret, sizeof(secret));
727 int tls13_alert_code(int code)
729 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
730 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
733 return tls1_alert_code(code);
736 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
737 const char *label, size_t llen,
738 const unsigned char *context,
739 size_t contextlen, int use_context)
741 unsigned char exportsecret[EVP_MAX_MD_SIZE];
742 static const unsigned char exporterlabel[] = "exporter";
743 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
744 const EVP_MD *md = ssl_handshake_md(s);
745 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
746 unsigned int hashsize, datalen;
749 if (ctx == NULL || !ossl_statem_export_allowed(s))
755 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
756 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
757 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
758 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
759 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
760 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
761 (const unsigned char *)label, llen,
762 data, datalen, exportsecret, hashsize, 0)
763 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
764 sizeof(exporterlabel) - 1, hash, hashsize,
770 EVP_MD_CTX_free(ctx);
774 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
775 const char *label, size_t llen,
776 const unsigned char *context,
779 static const unsigned char exporterlabel[] = "exporter";
780 unsigned char exportsecret[EVP_MAX_MD_SIZE];
781 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
783 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
784 unsigned int hashsize, datalen;
786 const SSL_CIPHER *sslcipher;
788 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
791 if (!s->server && s->max_early_data > 0
792 && s->session->ext.max_early_data == 0)
793 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
795 sslcipher = SSL_SESSION_get0_cipher(s->session);
797 md = ssl_md(sslcipher->algorithm2);
800 * Calculate the hash value and store it in |data|. The reason why
801 * the empty string is used is that the definition of TLS-Exporter
804 * TLS-Exporter(label, context_value, key_length) =
805 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
806 * "exporter", Hash(context_value), key_length)
808 * Derive-Secret(Secret, Label, Messages) =
809 * HKDF-Expand-Label(Secret, Label,
810 * Transcript-Hash(Messages), Hash.length)
812 * Here Transcript-Hash is the cipher suite hash algorithm.
814 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
815 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
816 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
817 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
818 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
819 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
820 (const unsigned char *)label, llen,
821 data, datalen, exportsecret, hashsize, 0)
822 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
823 sizeof(exporterlabel) - 1, hash, hashsize,
829 EVP_MD_CTX_free(ctx);