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)
34 static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 };
36 static const unsigned char label_prefix[] = "tls13 ";
38 EVP_KDF_CTX *kctx = EVP_KDF_CTX_new_id(EVP_PKEY_HKDF);
43 * 2 bytes for length of derived secret + 1 byte for length of combined
44 * prefix and label + bytes for the label itself + 1 byte length of hash
45 * + bytes for the hash itself
47 unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) +
48 + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN
49 + 1 + EVP_MAX_MD_SIZE];
55 if (labellen > TLS13_MAX_LABEL_LEN) {
57 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
58 ERR_R_INTERNAL_ERROR);
61 * Probably we have been called from SSL_export_keying_material(),
62 * or SSL_export_keying_material_early().
64 SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
66 EVP_KDF_CTX_free(kctx);
70 hashlen = EVP_MD_size(md);
72 if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
73 || !WPACKET_put_bytes_u16(&pkt, outlen)
74 || !WPACKET_start_sub_packet_u8(&pkt)
75 || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
76 || !WPACKET_memcpy(&pkt, label, labellen)
77 || !WPACKET_close(&pkt)
78 || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
79 || !WPACKET_get_total_written(&pkt, &hkdflabellen)
80 || !WPACKET_finish(&pkt)) {
81 EVP_KDF_CTX_free(kctx);
82 WPACKET_cleanup(&pkt);
84 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
85 ERR_R_INTERNAL_ERROR);
87 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
91 ret = EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_HKDF_MODE,
92 EVP_PKEY_HKDEF_MODE_EXPAND_ONLY) <= 0
93 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_MD, md) <= 0
94 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_KEY, secret, hashlen) <= 0
95 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_ADD_HKDF_INFO,
96 hkdflabel, hkdflabellen) <= 0
97 || EVP_KDF_derive(kctx, out, outlen) <= 0;
99 EVP_KDF_CTX_free(kctx);
103 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
104 ERR_R_INTERNAL_ERROR);
106 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
113 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
114 * success 0 on failure.
116 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
117 unsigned char *key, size_t keylen)
119 #ifdef CHARSET_EBCDIC
120 static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 };
122 static const unsigned char keylabel[] = "key";
125 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
126 NULL, 0, key, keylen, 1);
130 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
131 * success 0 on failure.
133 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
134 unsigned char *iv, size_t ivlen)
136 #ifdef CHARSET_EBCDIC
137 static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 };
139 static const unsigned char ivlabel[] = "iv";
142 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
143 NULL, 0, iv, ivlen, 1);
146 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
147 const unsigned char *secret,
148 unsigned char *fin, size_t finlen)
150 #ifdef CHARSET_EBCDIC
151 static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 };
153 static const unsigned char finishedlabel[] = "finished";
156 return tls13_hkdf_expand(s, md, secret, finishedlabel,
157 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
161 * Given the previous secret |prevsecret| and a new input secret |insecret| of
162 * length |insecretlen|, generate a new secret and store it in the location
163 * pointed to by |outsecret|. Returns 1 on success 0 on failure.
165 int tls13_generate_secret(SSL *s, const EVP_MD *md,
166 const unsigned char *prevsecret,
167 const unsigned char *insecret,
169 unsigned char *outsecret)
171 size_t mdlen, prevsecretlen;
174 EVP_KDF_CTX *kctx = EVP_KDF_CTX_new_id(EVP_PKEY_HKDF);
175 #ifdef CHARSET_EBCDIC
176 static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 };
178 static const char derived_secret_label[] = "derived";
180 unsigned char preextractsec[EVP_MAX_MD_SIZE];
183 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
184 ERR_R_INTERNAL_ERROR);
188 mdleni = EVP_MD_size(md);
189 /* Ensure cast to size_t is safe */
190 if (!ossl_assert(mdleni >= 0)) {
191 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
192 ERR_R_INTERNAL_ERROR);
193 EVP_KDF_CTX_free(kctx);
196 mdlen = (size_t)mdleni;
198 if (insecret == NULL) {
199 insecret = default_zeros;
202 if (prevsecret == NULL) {
203 prevsecret = default_zeros;
206 EVP_MD_CTX *mctx = EVP_MD_CTX_new();
207 unsigned char hash[EVP_MAX_MD_SIZE];
209 /* The pre-extract derive step uses a hash of no messages */
211 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
212 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
213 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
214 ERR_R_INTERNAL_ERROR);
215 EVP_MD_CTX_free(mctx);
216 EVP_KDF_CTX_free(kctx);
219 EVP_MD_CTX_free(mctx);
221 /* Generate the pre-extract secret */
222 if (!tls13_hkdf_expand(s, md, prevsecret,
223 (unsigned char *)derived_secret_label,
224 sizeof(derived_secret_label) - 1, hash, mdlen,
225 preextractsec, mdlen, 1)) {
226 /* SSLfatal() already called */
227 EVP_KDF_CTX_free(kctx);
231 prevsecret = preextractsec;
232 prevsecretlen = mdlen;
235 ret = EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_HKDF_MODE,
236 EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) <= 0
237 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_MD, md) <= 0
238 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_KEY, insecret, insecretlen) <= 0
239 || EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_SALT,
240 prevsecret, prevsecretlen) <= 0
241 || EVP_KDF_derive(kctx, outsecret, mdlen) <= 0;
244 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
245 ERR_R_INTERNAL_ERROR);
247 EVP_KDF_CTX_free(kctx);
248 if (prevsecret == preextractsec)
249 OPENSSL_cleanse(preextractsec, mdlen);
254 * Given an input secret |insecret| of length |insecretlen| generate the
255 * handshake secret. This requires the early secret to already have been
256 * generated. Returns 1 on success 0 on failure.
258 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
261 /* Calls SSLfatal() if required */
262 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
263 insecret, insecretlen,
264 (unsigned char *)&s->handshake_secret);
268 * Given the handshake secret |prev| of length |prevlen| generate the master
269 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
272 int tls13_generate_master_secret(SSL *s, unsigned char *out,
273 unsigned char *prev, size_t prevlen,
276 const EVP_MD *md = ssl_handshake_md(s);
278 *secret_size = EVP_MD_size(md);
279 /* Calls SSLfatal() if required */
280 return tls13_generate_secret(s, md, prev, NULL, 0, out);
284 * Generates the mac for the Finished message. Returns the length of the MAC or
287 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
290 const EVP_MD *md = ssl_handshake_md(s);
291 unsigned char hash[EVP_MAX_MD_SIZE];
292 size_t hashlen, ret = 0;
293 EVP_PKEY *key = NULL;
294 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
296 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
297 /* SSLfatal() already called */
301 if (str == s->method->ssl3_enc->server_finished_label) {
302 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
303 s->server_finished_secret, hashlen);
304 } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
305 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
306 s->client_finished_secret, hashlen);
308 unsigned char finsecret[EVP_MAX_MD_SIZE];
310 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
311 s->client_app_traffic_secret,
315 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret,
317 OPENSSL_cleanse(finsecret, sizeof(finsecret));
322 || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0
323 || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0
324 || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) {
325 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
326 ERR_R_INTERNAL_ERROR);
333 EVP_MD_CTX_free(ctx);
338 * There isn't really a key block in TLSv1.3, but we still need this function
339 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
341 int tls13_setup_key_block(SSL *s)
346 s->session->cipher = s->s3.tmp.new_cipher;
347 if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) {
348 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK,
349 SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
353 s->s3.tmp.new_sym_enc = c;
354 s->s3.tmp.new_hash = hash;
359 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
360 const EVP_CIPHER *ciph,
361 const unsigned char *insecret,
362 const unsigned char *hash,
363 const unsigned char *label,
364 size_t labellen, unsigned char *secret,
365 unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx)
367 unsigned char key[EVP_MAX_KEY_LENGTH];
368 size_t ivlen, keylen, taglen;
369 int hashleni = EVP_MD_size(md);
372 /* Ensure cast to size_t is safe */
373 if (!ossl_assert(hashleni >= 0)) {
374 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
378 hashlen = (size_t)hashleni;
380 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
381 secret, hashlen, 1)) {
382 /* SSLfatal() already called */
386 /* TODO(size_t): convert me */
387 keylen = EVP_CIPHER_key_length(ciph);
388 if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
391 ivlen = EVP_CCM_TLS_IV_LEN;
392 if (s->s3.tmp.new_cipher == NULL) {
393 /* We've not selected a cipher yet - we must be doing early data */
394 algenc = s->session->cipher->algorithm_enc;
396 algenc = s->s3.tmp.new_cipher->algorithm_enc;
398 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
399 taglen = EVP_CCM8_TLS_TAG_LEN;
401 taglen = EVP_CCM_TLS_TAG_LEN;
403 ivlen = EVP_CIPHER_iv_length(ciph);
407 if (!tls13_derive_key(s, md, secret, key, keylen)
408 || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
409 /* SSLfatal() already called */
413 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
414 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
415 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
417 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
418 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
425 OPENSSL_cleanse(key, sizeof(key));
429 int tls13_change_cipher_state(SSL *s, int which)
431 #ifdef CHARSET_EBCDIC
432 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
433 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
434 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
435 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
436 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
437 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
438 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
439 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
441 static const unsigned char client_early_traffic[] = "c e traffic";
442 static const unsigned char client_handshake_traffic[] = "c hs traffic";
443 static const unsigned char client_application_traffic[] = "c ap traffic";
444 static const unsigned char server_handshake_traffic[] = "s hs traffic";
445 static const unsigned char server_application_traffic[] = "s ap traffic";
446 static const unsigned char exporter_master_secret[] = "exp master";
447 static const unsigned char resumption_master_secret[] = "res master";
448 static const unsigned char early_exporter_master_secret[] = "e exp master";
451 unsigned char secret[EVP_MAX_MD_SIZE];
452 unsigned char hashval[EVP_MAX_MD_SIZE];
453 unsigned char *hash = hashval;
454 unsigned char *insecret;
455 unsigned char *finsecret = NULL;
456 const char *log_label = NULL;
457 EVP_CIPHER_CTX *ciph_ctx;
458 size_t finsecretlen = 0;
459 const unsigned char *label;
460 size_t labellen, hashlen = 0;
462 const EVP_MD *md = NULL;
463 const EVP_CIPHER *cipher = NULL;
465 if (which & SSL3_CC_READ) {
466 if (s->enc_read_ctx != NULL) {
467 EVP_CIPHER_CTX_reset(s->enc_read_ctx);
469 s->enc_read_ctx = EVP_CIPHER_CTX_new();
470 if (s->enc_read_ctx == NULL) {
471 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
472 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
476 ciph_ctx = s->enc_read_ctx;
479 RECORD_LAYER_reset_read_sequence(&s->rlayer);
481 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
482 if (s->enc_write_ctx != NULL) {
483 EVP_CIPHER_CTX_reset(s->enc_write_ctx);
485 s->enc_write_ctx = EVP_CIPHER_CTX_new();
486 if (s->enc_write_ctx == NULL) {
487 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
488 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
492 ciph_ctx = s->enc_write_ctx;
495 RECORD_LAYER_reset_write_sequence(&s->rlayer);
498 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
499 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
500 if (which & SSL3_CC_EARLY) {
501 EVP_MD_CTX *mdctx = NULL;
504 unsigned int hashlenui;
505 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
507 insecret = s->early_secret;
508 label = client_early_traffic;
509 labellen = sizeof(client_early_traffic) - 1;
510 log_label = CLIENT_EARLY_LABEL;
512 handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
514 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
515 SSL_F_TLS13_CHANGE_CIPHER_STATE,
516 SSL_R_BAD_HANDSHAKE_LENGTH);
520 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
521 && s->max_early_data > 0
522 && s->session->ext.max_early_data == 0) {
524 * If we are attempting to send early data, and we've decided to
525 * actually do it but max_early_data in s->session is 0 then we
526 * must be using an external PSK.
528 if (!ossl_assert(s->psksession != NULL
529 && s->max_early_data ==
530 s->psksession->ext.max_early_data)) {
531 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
532 SSL_F_TLS13_CHANGE_CIPHER_STATE,
533 ERR_R_INTERNAL_ERROR);
536 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
538 if (sslcipher == NULL) {
539 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
540 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK);
545 * We need to calculate the handshake digest using the digest from
546 * the session. We haven't yet selected our ciphersuite so we can't
547 * use ssl_handshake_md().
549 mdctx = EVP_MD_CTX_new();
551 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
552 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
555 cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher));
556 md = ssl_md(sslcipher->algorithm2);
557 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
558 || !EVP_DigestUpdate(mdctx, hdata, handlen)
559 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
560 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
561 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
562 EVP_MD_CTX_free(mdctx);
566 EVP_MD_CTX_free(mdctx);
568 if (!tls13_hkdf_expand(s, md, insecret,
569 early_exporter_master_secret,
570 sizeof(early_exporter_master_secret) - 1,
572 s->early_exporter_master_secret, hashlen,
574 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
575 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
579 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
580 s->early_exporter_master_secret, hashlen)) {
581 /* SSLfatal() already called */
584 } else if (which & SSL3_CC_HANDSHAKE) {
585 insecret = s->handshake_secret;
586 finsecret = s->client_finished_secret;
587 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
588 label = client_handshake_traffic;
589 labellen = sizeof(client_handshake_traffic) - 1;
590 log_label = CLIENT_HANDSHAKE_LABEL;
592 * The handshake hash used for the server read/client write handshake
593 * traffic secret is the same as the hash for the server
594 * write/client read handshake traffic secret. However, if we
595 * processed early data then we delay changing the server
596 * read/client write cipher state until later, and the handshake
597 * hashes have moved on. Therefore we use the value saved earlier
598 * when we did the server write/client read change cipher state.
600 hash = s->handshake_traffic_hash;
602 insecret = s->master_secret;
603 label = client_application_traffic;
604 labellen = sizeof(client_application_traffic) - 1;
605 log_label = CLIENT_APPLICATION_LABEL;
607 * For this we only use the handshake hashes up until the server
608 * Finished hash. We do not include the client's Finished, which is
609 * what ssl_handshake_hash() would give us. Instead we use the
610 * previously saved value.
612 hash = s->server_finished_hash;
615 /* Early data never applies to client-read/server-write */
616 if (which & SSL3_CC_HANDSHAKE) {
617 insecret = s->handshake_secret;
618 finsecret = s->server_finished_secret;
619 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
620 label = server_handshake_traffic;
621 labellen = sizeof(server_handshake_traffic) - 1;
622 log_label = SERVER_HANDSHAKE_LABEL;
624 insecret = s->master_secret;
625 label = server_application_traffic;
626 labellen = sizeof(server_application_traffic) - 1;
627 log_label = SERVER_APPLICATION_LABEL;
631 if (!(which & SSL3_CC_EARLY)) {
632 md = ssl_handshake_md(s);
633 cipher = s->s3.tmp.new_sym_enc;
634 if (!ssl3_digest_cached_records(s, 1)
635 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
636 /* SSLfatal() already called */;
642 * Save the hash of handshakes up to now for use when we calculate the
643 * client application traffic secret
645 if (label == server_application_traffic)
646 memcpy(s->server_finished_hash, hashval, hashlen);
648 if (label == server_handshake_traffic)
649 memcpy(s->handshake_traffic_hash, hashval, hashlen);
651 if (label == client_application_traffic) {
653 * We also create the resumption master secret, but this time use the
654 * hash for the whole handshake including the Client Finished
656 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
657 resumption_master_secret,
658 sizeof(resumption_master_secret) - 1,
659 hashval, hashlen, s->resumption_master_secret,
661 /* SSLfatal() already called */
666 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
667 insecret, hash, label, labellen, secret, iv,
669 /* SSLfatal() already called */
673 if (label == server_application_traffic) {
674 memcpy(s->server_app_traffic_secret, secret, hashlen);
675 /* Now we create the exporter master secret */
676 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
677 exporter_master_secret,
678 sizeof(exporter_master_secret) - 1,
679 hash, hashlen, s->exporter_master_secret,
681 /* SSLfatal() already called */
685 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
687 /* SSLfatal() already called */
690 } else if (label == client_application_traffic)
691 memcpy(s->client_app_traffic_secret, secret, hashlen);
693 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
694 /* SSLfatal() already called */
698 if (finsecret != NULL
699 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
700 finsecret, finsecretlen)) {
701 /* SSLfatal() already called */
705 if (!s->server && label == client_early_traffic)
706 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
708 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
711 OPENSSL_cleanse(secret, sizeof(secret));
715 int tls13_update_key(SSL *s, int sending)
717 #ifdef CHARSET_EBCDIC
718 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
720 static const unsigned char application_traffic[] = "traffic upd";
722 const EVP_MD *md = ssl_handshake_md(s);
723 size_t hashlen = EVP_MD_size(md);
724 unsigned char *insecret, *iv;
725 unsigned char secret[EVP_MAX_MD_SIZE];
726 EVP_CIPHER_CTX *ciph_ctx;
729 if (s->server == sending)
730 insecret = s->server_app_traffic_secret;
732 insecret = s->client_app_traffic_secret;
735 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
737 ciph_ctx = s->enc_write_ctx;
738 RECORD_LAYER_reset_write_sequence(&s->rlayer);
741 ciph_ctx = s->enc_read_ctx;
742 RECORD_LAYER_reset_read_sequence(&s->rlayer);
745 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
746 s->s3.tmp.new_sym_enc, insecret, NULL,
748 sizeof(application_traffic) - 1, secret, iv,
750 /* SSLfatal() already called */
754 memcpy(insecret, secret, hashlen);
756 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
759 OPENSSL_cleanse(secret, sizeof(secret));
763 int tls13_alert_code(int code)
765 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
766 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
769 return tls1_alert_code(code);
772 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
773 const char *label, size_t llen,
774 const unsigned char *context,
775 size_t contextlen, int use_context)
777 unsigned char exportsecret[EVP_MAX_MD_SIZE];
778 #ifdef CHARSET_EBCDIC
779 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
781 static const unsigned char exporterlabel[] = "exporter";
783 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
784 const EVP_MD *md = ssl_handshake_md(s);
785 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
786 unsigned int hashsize, datalen;
789 if (ctx == NULL || !ossl_statem_export_allowed(s))
795 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
796 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
797 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
798 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
799 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
800 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
801 (const unsigned char *)label, llen,
802 data, datalen, exportsecret, hashsize, 0)
803 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
804 sizeof(exporterlabel) - 1, hash, hashsize,
810 EVP_MD_CTX_free(ctx);
814 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
815 const char *label, size_t llen,
816 const unsigned char *context,
819 #ifdef CHARSET_EBCDIC
820 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
822 static const unsigned char exporterlabel[] = "exporter";
824 unsigned char exportsecret[EVP_MAX_MD_SIZE];
825 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
827 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
828 unsigned int hashsize, datalen;
830 const SSL_CIPHER *sslcipher;
832 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
835 if (!s->server && s->max_early_data > 0
836 && s->session->ext.max_early_data == 0)
837 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
839 sslcipher = SSL_SESSION_get0_cipher(s->session);
841 md = ssl_md(sslcipher->algorithm2);
844 * Calculate the hash value and store it in |data|. The reason why
845 * the empty string is used is that the definition of TLS-Exporter
848 * TLS-Exporter(label, context_value, key_length) =
849 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
850 * "exporter", Hash(context_value), key_length)
852 * Derive-Secret(Secret, Label, Messages) =
853 * HKDF-Expand-Label(Secret, Label,
854 * Transcript-Hash(Messages), Hash.length)
856 * Here Transcript-Hash is the cipher suite hash algorithm.
858 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
859 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
860 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
861 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
862 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
863 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
864 (const unsigned char *)label, llen,
865 data, datalen, exportsecret, hashsize, 0)
866 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
867 sizeof(exporterlabel) - 1, hash, hashsize,
873 EVP_MD_CTX_free(ctx);