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
);