2 * Copyright 2016-2021 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
11 #include "ssl_local.h"
12 #include "internal/ktls.h"
13 #include "record/record_local.h"
14 #include "internal/cryptlib.h"
15 #include <openssl/evp.h>
16 #include <openssl/kdf.h>
17 #include <openssl/core_names.h>
19 #define TLS13_MAX_LABEL_LEN 249
21 /* Always filled with zeros */
22 static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
25 * Given a |secret|; a |label| of length |labellen|; and |data| of length
26 * |datalen| (e.g. typically a hash of the handshake messages), derive a new
27 * secret |outlen| bytes long and store it in the location pointed to be |out|.
28 * The |data| value may be zero length. Any errors will be treated as fatal if
29 * |fatal| is set. Returns 1 on success 0 on failure.
31 int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
32 const unsigned char *label, size_t labellen,
33 const unsigned char *data, size_t datalen,
34 unsigned char *out, size_t outlen, int fatal)
37 static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 };
39 static const unsigned char label_prefix[] = "tls13 ";
41 EVP_KDF *kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_HKDF,
44 OSSL_PARAM params[5], *p = params;
45 int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY;
46 const char *mdname = EVP_MD_get0_name(md);
51 * 2 bytes for length of derived secret + 1 byte for length of combined
52 * prefix and label + bytes for the label itself + 1 byte length of hash
53 * + bytes for the hash itself
55 unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t)
56 + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN
57 + 1 + EVP_MAX_MD_SIZE];
60 kctx = EVP_KDF_CTX_new(kdf);
65 if (labellen > TLS13_MAX_LABEL_LEN) {
67 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
70 * Probably we have been called from SSL_export_keying_material(),
71 * or SSL_export_keying_material_early().
73 ERR_raise(ERR_LIB_SSL, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
75 EVP_KDF_CTX_free(kctx);
79 hashlen = EVP_MD_get_size(md);
81 if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
82 || !WPACKET_put_bytes_u16(&pkt, outlen)
83 || !WPACKET_start_sub_packet_u8(&pkt)
84 || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
85 || !WPACKET_memcpy(&pkt, label, labellen)
86 || !WPACKET_close(&pkt)
87 || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
88 || !WPACKET_get_total_written(&pkt, &hkdflabellen)
89 || !WPACKET_finish(&pkt)) {
90 EVP_KDF_CTX_free(kctx);
91 WPACKET_cleanup(&pkt);
93 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
95 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
99 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
100 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
102 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
103 (unsigned char *)secret, hashlen);
104 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_INFO,
105 hkdflabel, hkdflabellen);
106 *p++ = OSSL_PARAM_construct_end();
108 ret = EVP_KDF_derive(kctx, out, outlen, params) <= 0;
110 EVP_KDF_CTX_free(kctx);
114 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
116 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
123 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
124 * success 0 on failure.
126 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
127 unsigned char *key, size_t keylen)
129 #ifdef CHARSET_EBCDIC
130 static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 };
132 static const unsigned char keylabel[] = "key";
135 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
136 NULL, 0, key, keylen, 1);
140 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
141 * success 0 on failure.
143 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
144 unsigned char *iv, size_t ivlen)
146 #ifdef CHARSET_EBCDIC
147 static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 };
149 static const unsigned char ivlabel[] = "iv";
152 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
153 NULL, 0, iv, ivlen, 1);
156 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
157 const unsigned char *secret,
158 unsigned char *fin, size_t finlen)
160 #ifdef CHARSET_EBCDIC
161 static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 };
163 static const unsigned char finishedlabel[] = "finished";
166 return tls13_hkdf_expand(s, md, secret, finishedlabel,
167 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
171 * Given the previous secret |prevsecret| and a new input secret |insecret| of
172 * length |insecretlen|, generate a new secret and store it in the location
173 * pointed to by |outsecret|. Returns 1 on success 0 on failure.
175 int tls13_generate_secret(SSL *s, const EVP_MD *md,
176 const unsigned char *prevsecret,
177 const unsigned char *insecret,
179 unsigned char *outsecret)
181 size_t mdlen, prevsecretlen;
186 OSSL_PARAM params[5], *p = params;
187 int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
188 const char *mdname = EVP_MD_get0_name(md);
189 #ifdef CHARSET_EBCDIC
190 static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 };
192 static const char derived_secret_label[] = "derived";
194 unsigned char preextractsec[EVP_MAX_MD_SIZE];
196 kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_HKDF, s->ctx->propq);
197 kctx = EVP_KDF_CTX_new(kdf);
200 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
204 mdleni = EVP_MD_get_size(md);
205 /* Ensure cast to size_t is safe */
206 if (!ossl_assert(mdleni >= 0)) {
207 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
208 EVP_KDF_CTX_free(kctx);
211 mdlen = (size_t)mdleni;
213 if (insecret == NULL) {
214 insecret = default_zeros;
217 if (prevsecret == NULL) {
218 prevsecret = default_zeros;
221 EVP_MD_CTX *mctx = EVP_MD_CTX_new();
222 unsigned char hash[EVP_MAX_MD_SIZE];
224 /* The pre-extract derive step uses a hash of no messages */
226 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
227 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
228 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
229 EVP_MD_CTX_free(mctx);
230 EVP_KDF_CTX_free(kctx);
233 EVP_MD_CTX_free(mctx);
235 /* Generate the pre-extract secret */
236 if (!tls13_hkdf_expand(s, md, prevsecret,
237 (unsigned char *)derived_secret_label,
238 sizeof(derived_secret_label) - 1, hash, mdlen,
239 preextractsec, mdlen, 1)) {
240 /* SSLfatal() already called */
241 EVP_KDF_CTX_free(kctx);
245 prevsecret = preextractsec;
246 prevsecretlen = mdlen;
249 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
250 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
252 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
253 (unsigned char *)insecret,
255 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
256 (unsigned char *)prevsecret,
258 *p++ = OSSL_PARAM_construct_end();
260 ret = EVP_KDF_derive(kctx, outsecret, mdlen, params) <= 0;
263 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
265 EVP_KDF_CTX_free(kctx);
266 if (prevsecret == preextractsec)
267 OPENSSL_cleanse(preextractsec, mdlen);
272 * Given an input secret |insecret| of length |insecretlen| generate the
273 * handshake secret. This requires the early secret to already have been
274 * generated. Returns 1 on success 0 on failure.
276 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
279 /* Calls SSLfatal() if required */
280 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
281 insecret, insecretlen,
282 (unsigned char *)&s->handshake_secret);
286 * Given the handshake secret |prev| of length |prevlen| generate the master
287 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
290 int tls13_generate_master_secret(SSL *s, unsigned char *out,
291 unsigned char *prev, size_t prevlen,
294 const EVP_MD *md = ssl_handshake_md(s);
296 *secret_size = EVP_MD_get_size(md);
297 /* Calls SSLfatal() if required */
298 return tls13_generate_secret(s, md, prev, NULL, 0, out);
302 * Generates the mac for the Finished message. Returns the length of the MAC or
305 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
308 const char *mdname = EVP_MD_get0_name(ssl_handshake_md(s));
309 unsigned char hash[EVP_MAX_MD_SIZE];
310 unsigned char finsecret[EVP_MAX_MD_SIZE];
311 unsigned char *key = NULL;
312 unsigned int len = 0;
313 size_t hashlen, ret = 0;
314 OSSL_PARAM params[2], *p = params;
316 /* Safe to cast away const here since we're not "getting" any data */
317 if (s->ctx->propq != NULL)
318 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
319 (char *)s->ctx->propq,
321 *p = OSSL_PARAM_construct_end();
323 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
324 /* SSLfatal() already called */
328 if (str == s->method->ssl3_enc->server_finished_label) {
329 key = s->server_finished_secret;
330 } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
331 key = s->client_finished_secret;
333 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
334 s->client_app_traffic_secret,
340 if (!EVP_Q_mac(s->ctx->libctx, "HMAC", s->ctx->propq, mdname,
341 params, key, hashlen, hash, hashlen,
342 /* outsize as per sizeof(peer_finish_md) */
343 out, EVP_MAX_MD_SIZE * 2, &len)) {
344 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
350 OPENSSL_cleanse(finsecret, sizeof(finsecret));
355 * There isn't really a key block in TLSv1.3, but we still need this function
356 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
358 int tls13_setup_key_block(SSL *s)
363 s->session->cipher = s->s3.tmp.new_cipher;
364 if (!ssl_cipher_get_evp(s->ctx, s->session, &c, &hash, NULL, NULL, NULL,
366 /* Error is already recorded */
367 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
371 ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
372 s->s3.tmp.new_sym_enc = c;
373 ssl_evp_md_free(s->s3.tmp.new_hash);
374 s->s3.tmp.new_hash = hash;
379 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
380 const EVP_CIPHER *ciph,
381 const unsigned char *insecret,
382 const unsigned char *hash,
383 const unsigned char *label,
384 size_t labellen, unsigned char *secret,
385 unsigned char *key, unsigned char *iv,
386 EVP_CIPHER_CTX *ciph_ctx)
388 size_t ivlen, keylen, taglen;
389 int hashleni = EVP_MD_get_size(md);
392 /* Ensure cast to size_t is safe */
393 if (!ossl_assert(hashleni >= 0)) {
394 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
397 hashlen = (size_t)hashleni;
399 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
400 secret, hashlen, 1)) {
401 /* SSLfatal() already called */
405 keylen = EVP_CIPHER_get_key_length(ciph);
406 if (EVP_CIPHER_get_mode(ciph) == EVP_CIPH_CCM_MODE) {
409 ivlen = EVP_CCM_TLS_IV_LEN;
410 if (s->s3.tmp.new_cipher != NULL) {
411 algenc = s->s3.tmp.new_cipher->algorithm_enc;
412 } else if (s->session->cipher != NULL) {
413 /* We've not selected a cipher yet - we must be doing early data */
414 algenc = s->session->cipher->algorithm_enc;
415 } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
416 /* We must be doing early data with out-of-band PSK */
417 algenc = s->psksession->cipher->algorithm_enc;
419 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
422 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
423 taglen = EVP_CCM8_TLS_TAG_LEN;
425 taglen = EVP_CCM_TLS_TAG_LEN;
427 ivlen = EVP_CIPHER_get_iv_length(ciph);
431 if (!tls13_derive_key(s, md, secret, key, keylen)
432 || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
433 /* SSLfatal() already called */
437 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
438 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
439 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
441 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
442 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
449 int tls13_change_cipher_state(SSL *s, int which)
451 #ifdef CHARSET_EBCDIC
452 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
453 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
454 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
455 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
456 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
457 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
458 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
459 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
461 static const unsigned char client_early_traffic[] = "c e traffic";
462 static const unsigned char client_handshake_traffic[] = "c hs traffic";
463 static const unsigned char client_application_traffic[] = "c ap traffic";
464 static const unsigned char server_handshake_traffic[] = "s hs traffic";
465 static const unsigned char server_application_traffic[] = "s ap traffic";
466 static const unsigned char exporter_master_secret[] = "exp master";
467 static const unsigned char resumption_master_secret[] = "res master";
468 static const unsigned char early_exporter_master_secret[] = "e exp master";
471 unsigned char key[EVP_MAX_KEY_LENGTH];
472 unsigned char secret[EVP_MAX_MD_SIZE];
473 unsigned char hashval[EVP_MAX_MD_SIZE];
474 unsigned char *hash = hashval;
475 unsigned char *insecret;
476 unsigned char *finsecret = NULL;
477 const char *log_label = NULL;
478 EVP_CIPHER_CTX *ciph_ctx;
479 size_t finsecretlen = 0;
480 const unsigned char *label;
481 size_t labellen, hashlen = 0;
483 const EVP_MD *md = NULL;
484 const EVP_CIPHER *cipher = NULL;
485 #if !defined(OPENSSL_NO_KTLS) && defined(OPENSSL_KTLS_TLS13)
486 ktls_crypto_info_t crypto_info;
490 if (which & SSL3_CC_READ) {
491 if (s->enc_read_ctx != NULL) {
492 EVP_CIPHER_CTX_reset(s->enc_read_ctx);
494 s->enc_read_ctx = EVP_CIPHER_CTX_new();
495 if (s->enc_read_ctx == NULL) {
496 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
500 ciph_ctx = s->enc_read_ctx;
503 RECORD_LAYER_reset_read_sequence(&s->rlayer);
505 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
506 if (s->enc_write_ctx != NULL) {
507 EVP_CIPHER_CTX_reset(s->enc_write_ctx);
509 s->enc_write_ctx = EVP_CIPHER_CTX_new();
510 if (s->enc_write_ctx == NULL) {
511 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
515 ciph_ctx = s->enc_write_ctx;
518 RECORD_LAYER_reset_write_sequence(&s->rlayer);
521 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
522 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
523 if (which & SSL3_CC_EARLY) {
524 EVP_MD_CTX *mdctx = NULL;
527 unsigned int hashlenui;
528 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
530 insecret = s->early_secret;
531 label = client_early_traffic;
532 labellen = sizeof(client_early_traffic) - 1;
533 log_label = CLIENT_EARLY_LABEL;
535 handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
537 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
541 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
542 && s->max_early_data > 0
543 && s->session->ext.max_early_data == 0) {
545 * If we are attempting to send early data, and we've decided to
546 * actually do it but max_early_data in s->session is 0 then we
547 * must be using an external PSK.
549 if (!ossl_assert(s->psksession != NULL
550 && s->max_early_data ==
551 s->psksession->ext.max_early_data)) {
552 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
555 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
557 if (sslcipher == NULL) {
558 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
563 * We need to calculate the handshake digest using the digest from
564 * the session. We haven't yet selected our ciphersuite so we can't
565 * use ssl_handshake_md().
567 mdctx = EVP_MD_CTX_new();
569 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
574 * This ups the ref count on cipher so we better make sure we free
577 if (!ssl_cipher_get_evp_cipher(s->ctx, sslcipher, &cipher)) {
578 /* Error is already recorded */
579 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
580 EVP_MD_CTX_free(mdctx);
584 md = ssl_md(s->ctx, sslcipher->algorithm2);
585 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
586 || !EVP_DigestUpdate(mdctx, hdata, handlen)
587 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
588 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
589 EVP_MD_CTX_free(mdctx);
593 EVP_MD_CTX_free(mdctx);
595 if (!tls13_hkdf_expand(s, md, insecret,
596 early_exporter_master_secret,
597 sizeof(early_exporter_master_secret) - 1,
599 s->early_exporter_master_secret, hashlen,
601 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
605 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
606 s->early_exporter_master_secret, hashlen)) {
607 /* SSLfatal() already called */
610 } else if (which & SSL3_CC_HANDSHAKE) {
611 insecret = s->handshake_secret;
612 finsecret = s->client_finished_secret;
613 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
614 label = client_handshake_traffic;
615 labellen = sizeof(client_handshake_traffic) - 1;
616 log_label = CLIENT_HANDSHAKE_LABEL;
618 * The handshake hash used for the server read/client write handshake
619 * traffic secret is the same as the hash for the server
620 * write/client read handshake traffic secret. However, if we
621 * processed early data then we delay changing the server
622 * read/client write cipher state until later, and the handshake
623 * hashes have moved on. Therefore we use the value saved earlier
624 * when we did the server write/client read change cipher state.
626 hash = s->handshake_traffic_hash;
628 insecret = s->master_secret;
629 label = client_application_traffic;
630 labellen = sizeof(client_application_traffic) - 1;
631 log_label = CLIENT_APPLICATION_LABEL;
633 * For this we only use the handshake hashes up until the server
634 * Finished hash. We do not include the client's Finished, which is
635 * what ssl_handshake_hash() would give us. Instead we use the
636 * previously saved value.
638 hash = s->server_finished_hash;
641 /* Early data never applies to client-read/server-write */
642 if (which & SSL3_CC_HANDSHAKE) {
643 insecret = s->handshake_secret;
644 finsecret = s->server_finished_secret;
645 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
646 label = server_handshake_traffic;
647 labellen = sizeof(server_handshake_traffic) - 1;
648 log_label = SERVER_HANDSHAKE_LABEL;
650 insecret = s->master_secret;
651 label = server_application_traffic;
652 labellen = sizeof(server_application_traffic) - 1;
653 log_label = SERVER_APPLICATION_LABEL;
657 if (!(which & SSL3_CC_EARLY)) {
658 md = ssl_handshake_md(s);
659 cipher = s->s3.tmp.new_sym_enc;
660 if (!ssl3_digest_cached_records(s, 1)
661 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
662 /* SSLfatal() already called */;
668 * Save the hash of handshakes up to now for use when we calculate the
669 * client application traffic secret
671 if (label == server_application_traffic)
672 memcpy(s->server_finished_hash, hashval, hashlen);
674 if (label == server_handshake_traffic)
675 memcpy(s->handshake_traffic_hash, hashval, hashlen);
677 if (label == client_application_traffic) {
679 * We also create the resumption master secret, but this time use the
680 * hash for the whole handshake including the Client Finished
682 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
683 resumption_master_secret,
684 sizeof(resumption_master_secret) - 1,
685 hashval, hashlen, s->resumption_master_secret,
687 /* SSLfatal() already called */
692 /* check whether cipher is known */
693 if(!ossl_assert(cipher != NULL))
696 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
697 insecret, hash, label, labellen, secret, key,
699 /* SSLfatal() already called */
703 if (label == server_application_traffic) {
704 memcpy(s->server_app_traffic_secret, secret, hashlen);
705 /* Now we create the exporter master secret */
706 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
707 exporter_master_secret,
708 sizeof(exporter_master_secret) - 1,
709 hash, hashlen, s->exporter_master_secret,
711 /* SSLfatal() already called */
715 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
717 /* SSLfatal() already called */
720 } else if (label == client_application_traffic)
721 memcpy(s->client_app_traffic_secret, secret, hashlen);
723 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
724 /* SSLfatal() already called */
728 if (finsecret != NULL
729 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
730 finsecret, finsecretlen)) {
731 /* SSLfatal() already called */
735 if (!s->server && label == client_early_traffic)
736 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
738 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
739 #ifndef OPENSSL_NO_KTLS
740 # if defined(OPENSSL_KTLS_TLS13)
741 if (!(which & SSL3_CC_WRITE)
742 || !(which & SSL3_CC_APPLICATION)
743 || (s->options & SSL_OP_ENABLE_KTLS) == 0)
746 /* ktls supports only the maximum fragment size */
747 if (ssl_get_max_send_fragment(s) != SSL3_RT_MAX_PLAIN_LENGTH)
750 /* ktls does not support record padding */
751 if (s->record_padding_cb != NULL)
754 /* check that cipher is supported */
755 if (!ktls_check_supported_cipher(s, cipher, ciph_ctx))
760 if (!ossl_assert(bio != NULL)) {
761 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
765 /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */
766 if (BIO_flush(bio) <= 0)
769 /* configure kernel crypto structure */
770 if (!ktls_configure_crypto(s, cipher, ciph_ctx,
771 RECORD_LAYER_get_write_sequence(&s->rlayer),
772 &crypto_info, NULL, iv, key, NULL, 0))
775 /* ktls works with user provided buffers directly */
776 if (BIO_set_ktls(bio, &crypto_info, which & SSL3_CC_WRITE))
777 ssl3_release_write_buffer(s);
783 if ((which & SSL3_CC_EARLY) != 0) {
784 /* We up-refed this so now we need to down ref */
785 ssl_evp_cipher_free(cipher);
787 OPENSSL_cleanse(key, sizeof(key));
788 OPENSSL_cleanse(secret, sizeof(secret));
792 int tls13_update_key(SSL *s, int sending)
794 #ifdef CHARSET_EBCDIC
795 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
797 static const unsigned char application_traffic[] = "traffic upd";
799 const EVP_MD *md = ssl_handshake_md(s);
800 size_t hashlen = EVP_MD_get_size(md);
801 unsigned char key[EVP_MAX_KEY_LENGTH];
802 unsigned char *insecret, *iv;
803 unsigned char secret[EVP_MAX_MD_SIZE];
804 EVP_CIPHER_CTX *ciph_ctx;
807 if (s->server == sending)
808 insecret = s->server_app_traffic_secret;
810 insecret = s->client_app_traffic_secret;
813 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
815 ciph_ctx = s->enc_write_ctx;
816 RECORD_LAYER_reset_write_sequence(&s->rlayer);
819 ciph_ctx = s->enc_read_ctx;
820 RECORD_LAYER_reset_read_sequence(&s->rlayer);
823 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
824 s->s3.tmp.new_sym_enc, insecret, NULL,
826 sizeof(application_traffic) - 1, secret, key,
828 /* SSLfatal() already called */
832 memcpy(insecret, secret, hashlen);
834 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
837 OPENSSL_cleanse(key, sizeof(key));
838 OPENSSL_cleanse(secret, sizeof(secret));
842 int tls13_alert_code(int code)
844 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
845 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
848 return tls1_alert_code(code);
851 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
852 const char *label, size_t llen,
853 const unsigned char *context,
854 size_t contextlen, int use_context)
856 unsigned char exportsecret[EVP_MAX_MD_SIZE];
857 #ifdef CHARSET_EBCDIC
858 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
860 static const unsigned char exporterlabel[] = "exporter";
862 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
863 const EVP_MD *md = ssl_handshake_md(s);
864 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
865 unsigned int hashsize, datalen;
868 if (ctx == NULL || !ossl_statem_export_allowed(s))
874 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
875 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
876 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
877 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
878 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
879 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
880 (const unsigned char *)label, llen,
881 data, datalen, exportsecret, hashsize, 0)
882 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
883 sizeof(exporterlabel) - 1, hash, hashsize,
889 EVP_MD_CTX_free(ctx);
893 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
894 const char *label, size_t llen,
895 const unsigned char *context,
898 #ifdef CHARSET_EBCDIC
899 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
901 static const unsigned char exporterlabel[] = "exporter";
903 unsigned char exportsecret[EVP_MAX_MD_SIZE];
904 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
906 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
907 unsigned int hashsize, datalen;
909 const SSL_CIPHER *sslcipher;
911 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
914 if (!s->server && s->max_early_data > 0
915 && s->session->ext.max_early_data == 0)
916 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
918 sslcipher = SSL_SESSION_get0_cipher(s->session);
920 md = ssl_md(s->ctx, sslcipher->algorithm2);
923 * Calculate the hash value and store it in |data|. The reason why
924 * the empty string is used is that the definition of TLS-Exporter
927 * TLS-Exporter(label, context_value, key_length) =
928 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
929 * "exporter", Hash(context_value), key_length)
931 * Derive-Secret(Secret, Label, Messages) =
932 * HKDF-Expand-Label(Secret, Label,
933 * Transcript-Hash(Messages), Hash.length)
935 * Here Transcript-Hash is the cipher suite hash algorithm.
937 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
938 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
939 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
940 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
941 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
942 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
943 (const unsigned char *)label, llen,
944 data, datalen, exportsecret, hashsize, 0)
945 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
946 sizeof(exporterlabel) - 1, hash, hashsize,
952 EVP_MD_CTX_free(ctx);