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[thirdparty/openssl.git] / ssl / tls13_enc.c
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34574f19 1/*
33388b44 2 * Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
34574f19 3 *
2c18d164 4 * Licensed under the Apache License 2.0 (the "License"). You may not use
34574f19
MC
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
8 */
9
10#include <stdlib.h>
706457b7 11#include "ssl_local.h"
cc10b56d
VF
12#include "internal/ktls.h"
13#include "record/record_local.h"
08717544 14#include "internal/cryptlib.h"
34574f19
MC
15#include <openssl/evp.h>
16#include <openssl/kdf.h>
ce3b1bb4 17#include <openssl/core_names.h>
34574f19 18
0fb2815b 19#define TLS13_MAX_LABEL_LEN 249
34574f19
MC
20
21/* Always filled with zeros */
22static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
23
34574f19 24/*
a19ae67d
MC
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|.
0fb2815b
MC
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.
34574f19 30 */
ec15acb6 31int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
34574f19 32 const unsigned char *label, size_t labellen,
a19ae67d 33 const unsigned char *data, size_t datalen,
0fb2815b 34 unsigned char *out, size_t outlen, int fatal)
34574f19 35{
48102247 36#ifdef CHARSET_EBCDIC
37 static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 };
38#else
0fb2815b 39 static const unsigned char label_prefix[] = "tls13 ";
48102247 40#endif
c8f6c28a
MC
41 EVP_KDF *kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_HKDF,
42 s->ctx->propq);
ce3b1bb4
P
43 EVP_KDF_CTX *kctx;
44 OSSL_PARAM params[5], *p = params;
45 int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY;
46 const char *mdname = EVP_MD_name(md);
34574f19
MC
47 int ret;
48 size_t hkdflabellen;
49 size_t hashlen;
50 /*
0fb2815b
MC
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
34574f19 54 */
2de5a5fb 55 unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t)
0b4233f5 56 + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN
0fb2815b 57 + 1 + EVP_MAX_MD_SIZE];
34574f19
MC
58 WPACKET pkt;
59
660c5344 60 kctx = EVP_KDF_CTX_new(kdf);
ce3b1bb4 61 EVP_KDF_free(kdf);
32495464 62 if (kctx == NULL)
34574f19
MC
63 return 0;
64
0fb2815b
MC
65 if (labellen > TLS13_MAX_LABEL_LEN) {
66 if (fatal) {
67 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
68 ERR_R_INTERNAL_ERROR);
69 } else {
70 /*
71 * Probably we have been called from SSL_export_keying_material(),
72 * or SSL_export_keying_material_early().
73 */
74 SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
75 }
660c5344 76 EVP_KDF_CTX_free(kctx);
0fb2815b
MC
77 return 0;
78 }
79
34574f19
MC
80 hashlen = EVP_MD_size(md);
81
82 if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
83 || !WPACKET_put_bytes_u16(&pkt, outlen)
84 || !WPACKET_start_sub_packet_u8(&pkt)
85 || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
86 || !WPACKET_memcpy(&pkt, label, labellen)
87 || !WPACKET_close(&pkt)
a19ae67d 88 || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
34574f19
MC
89 || !WPACKET_get_total_written(&pkt, &hkdflabellen)
90 || !WPACKET_finish(&pkt)) {
660c5344 91 EVP_KDF_CTX_free(kctx);
34574f19 92 WPACKET_cleanup(&pkt);
0fb2815b
MC
93 if (fatal)
94 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
95 ERR_R_INTERNAL_ERROR);
96 else
97 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
34574f19
MC
98 return 0;
99 }
100
ce3b1bb4
P
101 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
102 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
8b6ffd40 103 (char *)mdname, 0);
ce3b1bb4
P
104 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
105 (unsigned char *)secret, hashlen);
106 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_INFO,
107 hkdflabel, hkdflabellen);
108 *p++ = OSSL_PARAM_construct_end();
109
660c5344 110 ret = EVP_KDF_CTX_set_params(kctx, params) <= 0
32495464 111 || EVP_KDF_derive(kctx, out, outlen) <= 0;
34574f19 112
660c5344 113 EVP_KDF_CTX_free(kctx);
34574f19 114
0fb2815b
MC
115 if (ret != 0) {
116 if (fatal)
117 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
118 ERR_R_INTERNAL_ERROR);
119 else
120 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
121 }
f63a17d6 122
34574f19
MC
123 return ret == 0;
124}
125
34574f19 126/*
f5ca0b04
MC
127 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
128 * success 0 on failure.
34574f19 129 */
d49e23ec
MC
130int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
131 unsigned char *key, size_t keylen)
34574f19 132{
48102247 133#ifdef CHARSET_EBCDIC
134 static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 };
135#else
136 static const unsigned char keylabel[] = "key";
137#endif
f5ca0b04 138
d49e23ec 139 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
0fb2815b 140 NULL, 0, key, keylen, 1);
34574f19
MC
141}
142
143/*
f5ca0b04
MC
144 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
145 * success 0 on failure.
34574f19 146 */
d49e23ec
MC
147int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
148 unsigned char *iv, size_t ivlen)
34574f19 149{
48102247 150#ifdef CHARSET_EBCDIC
151 static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 };
152#else
153 static const unsigned char ivlabel[] = "iv";
154#endif
f5ca0b04 155
d49e23ec 156 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
0fb2815b 157 NULL, 0, iv, ivlen, 1);
34574f19
MC
158}
159
ec15acb6
MC
160int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
161 const unsigned char *secret,
162 unsigned char *fin, size_t finlen)
6484776f 163{
48102247 164#ifdef CHARSET_EBCDIC
165 static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 };
166#else
167 static const unsigned char finishedlabel[] = "finished";
168#endif
f5ca0b04 169
ec15acb6 170 return tls13_hkdf_expand(s, md, secret, finishedlabel,
0fb2815b 171 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
6484776f
MC
172}
173
34574f19
MC
174/*
175 * Given the previous secret |prevsecret| and a new input secret |insecret| of
176 * length |insecretlen|, generate a new secret and store it in the location
f5ca0b04 177 * pointed to by |outsecret|. Returns 1 on success 0 on failure.
34574f19 178 */
ec15acb6
MC
179int tls13_generate_secret(SSL *s, const EVP_MD *md,
180 const unsigned char *prevsecret,
181 const unsigned char *insecret,
182 size_t insecretlen,
183 unsigned char *outsecret)
34574f19 184{
34574f19 185 size_t mdlen, prevsecretlen;
bceae201 186 int mdleni;
34574f19 187 int ret;
ce3b1bb4
P
188 EVP_KDF *kdf;
189 EVP_KDF_CTX *kctx;
190 OSSL_PARAM params[5], *p = params;
191 int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
192 const char *mdname = EVP_MD_name(md);
48102247 193#ifdef CHARSET_EBCDIC
194 static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 };
195#else
17aa119e 196 static const char derived_secret_label[] = "derived";
48102247 197#endif
3e0458fb 198 unsigned char preextractsec[EVP_MAX_MD_SIZE];
34574f19 199
c8f6c28a 200 kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_HKDF, s->ctx->propq);
660c5344 201 kctx = EVP_KDF_CTX_new(kdf);
ce3b1bb4 202 EVP_KDF_free(kdf);
32495464 203 if (kctx == NULL) {
f63a17d6
MC
204 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
205 ERR_R_INTERNAL_ERROR);
34574f19 206 return 0;
f63a17d6 207 }
34574f19 208
bceae201
MC
209 mdleni = EVP_MD_size(md);
210 /* Ensure cast to size_t is safe */
211 if (!ossl_assert(mdleni >= 0)) {
212 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
213 ERR_R_INTERNAL_ERROR);
660c5344 214 EVP_KDF_CTX_free(kctx);
bceae201
MC
215 return 0;
216 }
217 mdlen = (size_t)mdleni;
34574f19
MC
218
219 if (insecret == NULL) {
220 insecret = default_zeros;
221 insecretlen = mdlen;
222 }
223 if (prevsecret == NULL) {
224 prevsecret = default_zeros;
225 prevsecretlen = 0;
226 } else {
3e0458fb
MC
227 EVP_MD_CTX *mctx = EVP_MD_CTX_new();
228 unsigned char hash[EVP_MAX_MD_SIZE];
229
230 /* The pre-extract derive step uses a hash of no messages */
231 if (mctx == NULL
232 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
233 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
f63a17d6
MC
234 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
235 ERR_R_INTERNAL_ERROR);
3e0458fb 236 EVP_MD_CTX_free(mctx);
660c5344 237 EVP_KDF_CTX_free(kctx);
3e0458fb
MC
238 return 0;
239 }
240 EVP_MD_CTX_free(mctx);
241
242 /* Generate the pre-extract secret */
243 if (!tls13_hkdf_expand(s, md, prevsecret,
244 (unsigned char *)derived_secret_label,
a19ae67d 245 sizeof(derived_secret_label) - 1, hash, mdlen,
0fb2815b 246 preextractsec, mdlen, 1)) {
f63a17d6 247 /* SSLfatal() already called */
660c5344 248 EVP_KDF_CTX_free(kctx);
3e0458fb 249 return 0;
71d8c138 250 }
3e0458fb
MC
251
252 prevsecret = preextractsec;
34574f19
MC
253 prevsecretlen = mdlen;
254 }
255
ce3b1bb4
P
256 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
257 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
8b6ffd40 258 (char *)mdname, 0);
ce3b1bb4
P
259 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
260 (unsigned char *)insecret,
261 insecretlen);
262 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
263 (unsigned char *)prevsecret,
264 prevsecretlen);
265 *p++ = OSSL_PARAM_construct_end();
266
660c5344 267 ret = EVP_KDF_CTX_set_params(kctx, params) <= 0
32495464 268 || EVP_KDF_derive(kctx, outsecret, mdlen) <= 0;
34574f19 269
f63a17d6
MC
270 if (ret != 0)
271 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
272 ERR_R_INTERNAL_ERROR);
273
660c5344 274 EVP_KDF_CTX_free(kctx);
3e0458fb
MC
275 if (prevsecret == preextractsec)
276 OPENSSL_cleanse(preextractsec, mdlen);
34574f19
MC
277 return ret == 0;
278}
279
34574f19
MC
280/*
281 * Given an input secret |insecret| of length |insecretlen| generate the
282 * handshake secret. This requires the early secret to already have been
f5ca0b04 283 * generated. Returns 1 on success 0 on failure.
34574f19
MC
284 */
285int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
286 size_t insecretlen)
287{
f63a17d6 288 /* Calls SSLfatal() if required */
ec15acb6
MC
289 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
290 insecret, insecretlen,
34574f19
MC
291 (unsigned char *)&s->handshake_secret);
292}
293
294/*
295 * Given the handshake secret |prev| of length |prevlen| generate the master
f5ca0b04
MC
296 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
297 * failure.
34574f19
MC
298 */
299int tls13_generate_master_secret(SSL *s, unsigned char *out,
300 unsigned char *prev, size_t prevlen,
301 size_t *secret_size)
302{
ec15acb6
MC
303 const EVP_MD *md = ssl_handshake_md(s);
304
305 *secret_size = EVP_MD_size(md);
f63a17d6 306 /* Calls SSLfatal() if required */
ec15acb6 307 return tls13_generate_secret(s, md, prev, NULL, 0, out);
34574f19
MC
308}
309
92760c21 310/*
f5ca0b04
MC
311 * Generates the mac for the Finished message. Returns the length of the MAC or
312 * 0 on error.
92760c21
MC
313 */
314size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
315 unsigned char *out)
316{
c8f6c28a
MC
317 const char *mdname = EVP_MD_name(ssl_handshake_md(s));
318 EVP_MAC *hmac = EVP_MAC_fetch(s->ctx->libctx, "HMAC", s->ctx->propq);
6484776f 319 unsigned char hash[EVP_MAX_MD_SIZE];
c8f6c28a 320 unsigned char finsecret[EVP_MAX_MD_SIZE];
6484776f 321 size_t hashlen, ret = 0;
c8f6c28a
MC
322 EVP_MAC_CTX *ctx = NULL;
323 OSSL_PARAM params[4], *p = params;
324
325 if (hmac == NULL) {
326 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
327 ERR_R_INTERNAL_ERROR);
328 goto err;
329 }
330
331 /* Safe to cast away const here since we're not "getting" any data */
332 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_DIGEST,
333 (char *)mdname, 0);
334 if (s->ctx->propq != NULL)
335 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
336 (char *)s->ctx->propq,
337 0);
92760c21 338
d4d2f3a4
MC
339 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
340 /* SSLfatal() already called */
6484776f 341 goto err;
d4d2f3a4 342 }
6484776f 343
de9f5b35 344 if (str == s->method->ssl3_enc->server_finished_label) {
c8f6c28a
MC
345 *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
346 s->server_finished_secret,
347 hashlen);
de9f5b35 348 } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
c8f6c28a
MC
349 *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
350 s->client_finished_secret,
351 hashlen);
de9f5b35 352 } else {
de9f5b35
MC
353 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
354 s->client_app_traffic_secret,
355 finsecret, hashlen))
356 goto err;
357
c8f6c28a
MC
358 *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, finsecret,
359 hashlen);
de9f5b35 360 }
c8f6c28a 361 *p++ = OSSL_PARAM_construct_end();
6484776f 362
865adf97 363 ctx = EVP_MAC_CTX_new(hmac);
c8f6c28a 364 if (ctx == NULL
865adf97 365 || !EVP_MAC_CTX_set_params(ctx, params)
c8f6c28a
MC
366 || !EVP_MAC_init(ctx)
367 || !EVP_MAC_update(ctx, hash, hashlen)
368 /* outsize as per sizeof(peer_finish_md) */
369 || !EVP_MAC_final(ctx, out, &hashlen, EVP_MAX_MD_SIZE * 2)) {
d4d2f3a4
MC
370 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
371 ERR_R_INTERNAL_ERROR);
6484776f 372 goto err;
d4d2f3a4 373 }
92760c21 374
6484776f
MC
375 ret = hashlen;
376 err:
c8f6c28a 377 OPENSSL_cleanse(finsecret, sizeof(finsecret));
865adf97 378 EVP_MAC_CTX_free(ctx);
c8f6c28a 379 EVP_MAC_free(hmac);
6484776f 380 return ret;
92760c21
MC
381}
382
383/*
384 * There isn't really a key block in TLSv1.3, but we still need this function
f5ca0b04 385 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
92760c21
MC
386 */
387int tls13_setup_key_block(SSL *s)
388{
389 const EVP_CIPHER *c;
390 const EVP_MD *hash;
92760c21 391
555cbb32 392 s->session->cipher = s->s3.tmp.new_cipher;
c8f6c28a
MC
393 if (!ssl_cipher_get_evp(s->ctx, s->session, &c, &hash, NULL, NULL, NULL,
394 0)) {
f63a17d6
MC
395 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK,
396 SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
92760c21
MC
397 return 0;
398 }
399
c8f6c28a 400 ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
555cbb32 401 s->s3.tmp.new_sym_enc = c;
c8f6c28a 402 ssl_evp_md_free(s->s3.tmp.new_hash);
555cbb32 403 s->s3.tmp.new_hash = hash;
92760c21
MC
404
405 return 1;
406}
407
d1186c30 408static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
d49e23ec 409 const EVP_CIPHER *ciph,
57389a32
MC
410 const unsigned char *insecret,
411 const unsigned char *hash,
412 const unsigned char *label,
413 size_t labellen, unsigned char *secret,
cc10b56d
VF
414 unsigned char *key, unsigned char *iv,
415 EVP_CIPHER_CTX *ciph_ctx)
57389a32 416{
57389a32 417 size_t ivlen, keylen, taglen;
bceae201
MC
418 int hashleni = EVP_MD_size(md);
419 size_t hashlen;
420
421 /* Ensure cast to size_t is safe */
422 if (!ossl_assert(hashleni >= 0)) {
423 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
424 ERR_R_EVP_LIB);
cc10b56d 425 return 0;
bceae201
MC
426 }
427 hashlen = (size_t)hashleni;
57389a32 428
a19ae67d 429 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
0fb2815b 430 secret, hashlen, 1)) {
f63a17d6 431 /* SSLfatal() already called */
cc10b56d 432 return 0;
57389a32
MC
433 }
434
435 /* TODO(size_t): convert me */
436 keylen = EVP_CIPHER_key_length(ciph);
437 if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
c117af67
MC
438 uint32_t algenc;
439
57389a32 440 ivlen = EVP_CCM_TLS_IV_LEN;
2e1a4f6a 441 if (s->s3.tmp.new_cipher != NULL) {
442 algenc = s->s3.tmp.new_cipher->algorithm_enc;
443 } else if (s->session->cipher != NULL) {
c117af67
MC
444 /* We've not selected a cipher yet - we must be doing early data */
445 algenc = s->session->cipher->algorithm_enc;
2e1a4f6a 446 } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
447 /* We must be doing early data with out-of-band PSK */
448 algenc = s->psksession->cipher->algorithm_enc;
c117af67 449 } else {
2e1a4f6a 450 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
451 ERR_R_EVP_LIB);
cc10b56d 452 return 0;
c117af67
MC
453 }
454 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
57389a32
MC
455 taglen = EVP_CCM8_TLS_TAG_LEN;
456 else
457 taglen = EVP_CCM_TLS_TAG_LEN;
458 } else {
459 ivlen = EVP_CIPHER_iv_length(ciph);
460 taglen = 0;
461 }
462
d49e23ec
MC
463 if (!tls13_derive_key(s, md, secret, key, keylen)
464 || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
f63a17d6 465 /* SSLfatal() already called */
cc10b56d 466 return 0;
57389a32
MC
467 }
468
d1186c30 469 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
57389a32
MC
470 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
471 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
472 taglen, NULL))
473 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
f63a17d6
MC
474 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
475 ERR_R_EVP_LIB);
cc10b56d 476 return 0;
57389a32
MC
477 }
478
57389a32 479 return 1;
57389a32
MC
480}
481
0d9824c1
MC
482int tls13_change_cipher_state(SSL *s, int which)
483{
48102247 484#ifdef CHARSET_EBCDIC
485 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
486 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
487 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
488 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
489 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
490 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
491 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
492 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
493#else
17aa119e
MC
494 static const unsigned char client_early_traffic[] = "c e traffic";
495 static const unsigned char client_handshake_traffic[] = "c hs traffic";
496 static const unsigned char client_application_traffic[] = "c ap traffic";
497 static const unsigned char server_handshake_traffic[] = "s hs traffic";
498 static const unsigned char server_application_traffic[] = "s ap traffic";
0ca8d1ec 499 static const unsigned char exporter_master_secret[] = "exp master";
17aa119e 500 static const unsigned char resumption_master_secret[] = "res master";
b38ede80 501 static const unsigned char early_exporter_master_secret[] = "e exp master";
48102247 502#endif
bebc0c7d 503 unsigned char *iv;
cc10b56d 504 unsigned char key[EVP_MAX_KEY_LENGTH];
0d9824c1 505 unsigned char secret[EVP_MAX_MD_SIZE];
ace081c1
MC
506 unsigned char hashval[EVP_MAX_MD_SIZE];
507 unsigned char *hash = hashval;
0d9824c1 508 unsigned char *insecret;
6484776f 509 unsigned char *finsecret = NULL;
2c7bd692 510 const char *log_label = NULL;
0d9824c1 511 EVP_CIPHER_CTX *ciph_ctx;
57389a32 512 size_t finsecretlen = 0;
0d9824c1 513 const unsigned char *label;
ace081c1 514 size_t labellen, hashlen = 0;
6530c490 515 int ret = 0;
42f50fdf
MC
516 const EVP_MD *md = NULL;
517 const EVP_CIPHER *cipher = NULL;
cc10b56d 518#if !defined(OPENSSL_NO_KTLS) && defined(OPENSSL_KTLS_TLS13)
c34ca13a 519 ktls_crypto_info_t crypto_info;
cc10b56d 520 BIO *bio;
cc10b56d 521#endif
0d9824c1
MC
522
523 if (which & SSL3_CC_READ) {
524 if (s->enc_read_ctx != NULL) {
525 EVP_CIPHER_CTX_reset(s->enc_read_ctx);
526 } else {
527 s->enc_read_ctx = EVP_CIPHER_CTX_new();
528 if (s->enc_read_ctx == NULL) {
f63a17d6
MC
529 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
530 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
0d9824c1
MC
531 goto err;
532 }
533 }
534 ciph_ctx = s->enc_read_ctx;
bebc0c7d 535 iv = s->read_iv;
0d9824c1
MC
536
537 RECORD_LAYER_reset_read_sequence(&s->rlayer);
538 } else {
7426cd34 539 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
0d9824c1
MC
540 if (s->enc_write_ctx != NULL) {
541 EVP_CIPHER_CTX_reset(s->enc_write_ctx);
542 } else {
543 s->enc_write_ctx = EVP_CIPHER_CTX_new();
544 if (s->enc_write_ctx == NULL) {
f63a17d6
MC
545 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
546 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
0d9824c1
MC
547 goto err;
548 }
549 }
550 ciph_ctx = s->enc_write_ctx;
bebc0c7d 551 iv = s->write_iv;
0d9824c1
MC
552
553 RECORD_LAYER_reset_write_sequence(&s->rlayer);
554 }
555
556 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
557 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
d49e23ec
MC
558 if (which & SSL3_CC_EARLY) {
559 EVP_MD_CTX *mdctx = NULL;
560 long handlen;
561 void *hdata;
562 unsigned int hashlenui;
563 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
564
565 insecret = s->early_secret;
566 label = client_early_traffic;
567 labellen = sizeof(client_early_traffic) - 1;
568 log_label = CLIENT_EARLY_LABEL;
569
555cbb32 570 handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
d49e23ec 571 if (handlen <= 0) {
f63a17d6
MC
572 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
573 SSL_F_TLS13_CHANGE_CIPHER_STATE,
574 SSL_R_BAD_HANDSHAKE_LENGTH);
d49e23ec
MC
575 goto err;
576 }
add8d0e9 577
08717544
MC
578 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
579 && s->max_early_data > 0
580 && s->session->ext.max_early_data == 0) {
581 /*
582 * If we are attempting to send early data, and we've decided to
583 * actually do it but max_early_data in s->session is 0 then we
584 * must be using an external PSK.
585 */
586 if (!ossl_assert(s->psksession != NULL
587 && s->max_early_data ==
588 s->psksession->ext.max_early_data)) {
f63a17d6
MC
589 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
590 SSL_F_TLS13_CHANGE_CIPHER_STATE,
591 ERR_R_INTERNAL_ERROR);
08717544
MC
592 goto err;
593 }
add8d0e9 594 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
08717544 595 }
d49e23ec 596 if (sslcipher == NULL) {
f63a17d6
MC
597 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
598 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK);
d49e23ec
MC
599 goto err;
600 }
601
602 /*
603 * We need to calculate the handshake digest using the digest from
604 * the session. We haven't yet selected our ciphersuite so we can't
605 * use ssl_handshake_md().
606 */
607 mdctx = EVP_MD_CTX_new();
608 if (mdctx == NULL) {
f63a17d6
MC
609 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
610 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
d49e23ec
MC
611 goto err;
612 }
9727f4e7
MC
613
614 /*
615 * This ups the ref count on cipher so we better make sure we free
616 * it again
617 */
618 if (!ssl_cipher_get_evp_cipher(s->ctx, sslcipher, &cipher)) {
619 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
620 SSL_F_TLS13_CHANGE_CIPHER_STATE,
621 SSL_R_ALGORITHM_FETCH_FAILED);
67d744b9 622 EVP_MD_CTX_free(mdctx);
9727f4e7
MC
623 goto err;
624 }
625
c8f6c28a 626 md = ssl_md(s->ctx, sslcipher->algorithm2);
d49e23ec
MC
627 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
628 || !EVP_DigestUpdate(mdctx, hdata, handlen)
629 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
f63a17d6
MC
630 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
631 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
d49e23ec
MC
632 EVP_MD_CTX_free(mdctx);
633 goto err;
634 }
635 hashlen = hashlenui;
636 EVP_MD_CTX_free(mdctx);
b38ede80
TT
637
638 if (!tls13_hkdf_expand(s, md, insecret,
639 early_exporter_master_secret,
640 sizeof(early_exporter_master_secret) - 1,
641 hashval, hashlen,
0fb2815b
MC
642 s->early_exporter_master_secret, hashlen,
643 1)) {
b38ede80
TT
644 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
645 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
646 goto err;
647 }
01a2a654
PW
648
649 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
650 s->early_exporter_master_secret, hashlen)) {
651 /* SSLfatal() already called */
652 goto err;
653 }
d49e23ec 654 } else if (which & SSL3_CC_HANDSHAKE) {
0d9824c1 655 insecret = s->handshake_secret;
6484776f 656 finsecret = s->client_finished_secret;
6612d87b 657 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
0d9824c1
MC
658 label = client_handshake_traffic;
659 labellen = sizeof(client_handshake_traffic) - 1;
2c7bd692 660 log_label = CLIENT_HANDSHAKE_LABEL;
fe5e20fd 661 /*
69687aa8 662 * The handshake hash used for the server read/client write handshake
f7e393be
MC
663 * traffic secret is the same as the hash for the server
664 * write/client read handshake traffic secret. However, if we
665 * processed early data then we delay changing the server
666 * read/client write cipher state until later, and the handshake
667 * hashes have moved on. Therefore we use the value saved earlier
668 * when we did the server write/client read change cipher state.
fe5e20fd 669 */
f7e393be 670 hash = s->handshake_traffic_hash;
0d9824c1 671 } else {
ec15acb6 672 insecret = s->master_secret;
0d9824c1
MC
673 label = client_application_traffic;
674 labellen = sizeof(client_application_traffic) - 1;
2c7bd692 675 log_label = CLIENT_APPLICATION_LABEL;
ace081c1
MC
676 /*
677 * For this we only use the handshake hashes up until the server
678 * Finished hash. We do not include the client's Finished, which is
679 * what ssl_handshake_hash() would give us. Instead we use the
680 * previously saved value.
681 */
682 hash = s->server_finished_hash;
0d9824c1
MC
683 }
684 } else {
d49e23ec 685 /* Early data never applies to client-read/server-write */
0d9824c1
MC
686 if (which & SSL3_CC_HANDSHAKE) {
687 insecret = s->handshake_secret;
6484776f 688 finsecret = s->server_finished_secret;
6612d87b 689 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
0d9824c1
MC
690 label = server_handshake_traffic;
691 labellen = sizeof(server_handshake_traffic) - 1;
2c7bd692 692 log_label = SERVER_HANDSHAKE_LABEL;
0d9824c1 693 } else {
ec15acb6 694 insecret = s->master_secret;
0d9824c1
MC
695 label = server_application_traffic;
696 labellen = sizeof(server_application_traffic) - 1;
2c7bd692 697 log_label = SERVER_APPLICATION_LABEL;
0d9824c1
MC
698 }
699 }
700
d49e23ec
MC
701 if (!(which & SSL3_CC_EARLY)) {
702 md = ssl_handshake_md(s);
555cbb32 703 cipher = s->s3.tmp.new_sym_enc;
d49e23ec
MC
704 if (!ssl3_digest_cached_records(s, 1)
705 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
f63a17d6 706 /* SSLfatal() already called */;
d49e23ec
MC
707 goto err;
708 }
ace081c1
MC
709 }
710
ec15acb6
MC
711 /*
712 * Save the hash of handshakes up to now for use when we calculate the
713 * client application traffic secret
714 */
715 if (label == server_application_traffic)
716 memcpy(s->server_finished_hash, hashval, hashlen);
717
f7e393be 718 if (label == server_handshake_traffic)
fe5e20fd
MC
719 memcpy(s->handshake_traffic_hash, hashval, hashlen);
720
ec15acb6
MC
721 if (label == client_application_traffic) {
722 /*
723 * We also create the resumption master secret, but this time use the
724 * hash for the whole handshake including the Client Finished
725 */
726 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
727 resumption_master_secret,
728 sizeof(resumption_master_secret) - 1,
4ff1a526 729 hashval, hashlen, s->resumption_master_secret,
0fb2815b 730 hashlen, 1)) {
f63a17d6 731 /* SSLfatal() already called */
ec15acb6
MC
732 goto err;
733 }
ec15acb6
MC
734 }
735
cc10b56d
VF
736 /* check whether cipher is known */
737 if(!ossl_assert(cipher != NULL))
738 goto err;
739
d49e23ec 740 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
cc10b56d
VF
741 insecret, hash, label, labellen, secret, key,
742 iv, ciph_ctx)) {
f63a17d6 743 /* SSLfatal() already called */
57389a32 744 goto err;
ec07b1d8 745 }
0d9824c1 746
2221ec10 747 if (label == server_application_traffic) {
57389a32 748 memcpy(s->server_app_traffic_secret, secret, hashlen);
2221ec10
TT
749 /* Now we create the exporter master secret */
750 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
751 exporter_master_secret,
752 sizeof(exporter_master_secret) - 1,
753 hash, hashlen, s->exporter_master_secret,
0fb2815b 754 hashlen, 1)) {
2221ec10
TT
755 /* SSLfatal() already called */
756 goto err;
757 }
6329ce8f
PW
758
759 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
760 hashlen)) {
761 /* SSLfatal() already called */
762 goto err;
763 }
2221ec10 764 } else if (label == client_application_traffic)
57389a32
MC
765 memcpy(s->client_app_traffic_secret, secret, hashlen);
766
2c7bd692 767 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
f63a17d6 768 /* SSLfatal() already called */
2c7bd692
CB
769 goto err;
770 }
771
57389a32
MC
772 if (finsecret != NULL
773 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
774 finsecret, finsecretlen)) {
f63a17d6 775 /* SSLfatal() already called */
0d9824c1
MC
776 goto err;
777 }
778
7426cd34
MC
779 if (!s->server && label == client_early_traffic)
780 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
781 else
782 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
cc10b56d
VF
783#ifndef OPENSSL_NO_KTLS
784# if defined(OPENSSL_KTLS_TLS13)
cc10b56d
VF
785 if (!(which & SSL3_CC_WRITE) || !(which & SSL3_CC_APPLICATION)
786 || ((which & SSL3_CC_WRITE) && (s->mode & SSL_MODE_NO_KTLS_TX)))
787 goto skip_ktls;
788
789 /* ktls supports only the maximum fragment size */
790 if (ssl_get_max_send_fragment(s) != SSL3_RT_MAX_PLAIN_LENGTH)
791 goto skip_ktls;
792
793 /* ktls does not support record padding */
794 if (s->record_padding_cb != NULL)
795 goto skip_ktls;
796
797 /* check that cipher is supported */
3e582606 798 if (!ktls_check_supported_cipher(s, cipher, ciph_ctx))
cc10b56d
VF
799 goto skip_ktls;
800
801 bio = s->wbio;
802
803 if (!ossl_assert(bio != NULL)) {
804 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_CHANGE_CIPHER_STATE,
805 ERR_R_INTERNAL_ERROR);
806 goto err;
807 }
808
809 /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */
810 if (BIO_flush(bio) <= 0)
811 goto skip_ktls;
812
813 /* configure kernel crypto structure */
3e582606 814 if (!ktls_configure_crypto(s, cipher, ciph_ctx,
cc10b56d 815 RECORD_LAYER_get_write_sequence(&s->rlayer),
3e582606 816 &crypto_info, NULL, iv, key, NULL, 0))
cc10b56d
VF
817 goto skip_ktls;
818
819 /* ktls works with user provided buffers directly */
820 if (BIO_set_ktls(bio, &crypto_info, which & SSL3_CC_WRITE))
821 ssl3_release_write_buffer(s);
cc10b56d
VF
822skip_ktls:
823# endif
824#endif
57389a32
MC
825 ret = 1;
826 err:
9727f4e7
MC
827 if ((which & SSL3_CC_EARLY) != 0) {
828 /* We up-refed this so now we need to down ref */
829 ssl_evp_cipher_free(cipher);
830 }
cc10b56d 831 OPENSSL_cleanse(key, sizeof(key));
57389a32
MC
832 OPENSSL_cleanse(secret, sizeof(secret));
833 return ret;
834}
0d9824c1 835
d1186c30 836int tls13_update_key(SSL *s, int sending)
57389a32 837{
48102247 838#ifdef CHARSET_EBCDIC
839 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
840#else
841 static const unsigned char application_traffic[] = "traffic upd";
842#endif
57389a32
MC
843 const EVP_MD *md = ssl_handshake_md(s);
844 size_t hashlen = EVP_MD_size(md);
cc10b56d 845 unsigned char key[EVP_MAX_KEY_LENGTH];
57389a32
MC
846 unsigned char *insecret, *iv;
847 unsigned char secret[EVP_MAX_MD_SIZE];
848 EVP_CIPHER_CTX *ciph_ctx;
849 int ret = 0;
0d9824c1 850
d1186c30 851 if (s->server == sending)
57389a32
MC
852 insecret = s->server_app_traffic_secret;
853 else
854 insecret = s->client_app_traffic_secret;
bebc0c7d 855
d1186c30 856 if (sending) {
7426cd34 857 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
57389a32
MC
858 iv = s->write_iv;
859 ciph_ctx = s->enc_write_ctx;
860 RECORD_LAYER_reset_write_sequence(&s->rlayer);
861 } else {
862 iv = s->read_iv;
863 ciph_ctx = s->enc_read_ctx;
864 RECORD_LAYER_reset_read_sequence(&s->rlayer);
0d9824c1 865 }
57389a32 866
d1186c30 867 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
555cbb32 868 s->s3.tmp.new_sym_enc, insecret, NULL,
d49e23ec 869 application_traffic,
cc10b56d
VF
870 sizeof(application_traffic) - 1, secret, key,
871 iv, ciph_ctx)) {
f63a17d6 872 /* SSLfatal() already called */
57389a32 873 goto err;
f63a17d6 874 }
57389a32
MC
875
876 memcpy(insecret, secret, hashlen);
0d9824c1 877
7426cd34 878 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
6530c490 879 ret = 1;
0d9824c1 880 err:
cc10b56d 881 OPENSSL_cleanse(key, sizeof(key));
0d9824c1 882 OPENSSL_cleanse(secret, sizeof(secret));
6530c490 883 return ret;
0d9824c1 884}
04904312
MC
885
886int tls13_alert_code(int code)
887{
43a0f273
MC
888 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
889 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
04904312
MC
890 return code;
891
892 return tls1_alert_code(code);
893}
0ca8d1ec
MC
894
895int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
896 const char *label, size_t llen,
897 const unsigned char *context,
898 size_t contextlen, int use_context)
899{
900 unsigned char exportsecret[EVP_MAX_MD_SIZE];
48102247 901#ifdef CHARSET_EBCDIC
902 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
903#else
0ca8d1ec 904 static const unsigned char exporterlabel[] = "exporter";
48102247 905#endif
c8b93876 906 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
0ca8d1ec
MC
907 const EVP_MD *md = ssl_handshake_md(s);
908 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
c8b93876 909 unsigned int hashsize, datalen;
0ca8d1ec
MC
910 int ret = 0;
911
1f5878b8 912 if (ctx == NULL || !ossl_statem_export_allowed(s))
0ca8d1ec
MC
913 goto err;
914
915 if (!use_context)
916 contextlen = 0;
917
918 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
919 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
920 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
c8b93876
TT
921 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
922 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
0ca8d1ec 923 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
c8b93876 924 (const unsigned char *)label, llen,
0fb2815b 925 data, datalen, exportsecret, hashsize, 0)
0ca8d1ec 926 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
a19ae67d 927 sizeof(exporterlabel) - 1, hash, hashsize,
0fb2815b 928 out, olen, 0))
0ca8d1ec
MC
929 goto err;
930
931 ret = 1;
932 err:
933 EVP_MD_CTX_free(ctx);
934 return ret;
935}
b38ede80
TT
936
937int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
938 const char *label, size_t llen,
939 const unsigned char *context,
940 size_t contextlen)
941{
48102247 942#ifdef CHARSET_EBCDIC
943 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
944#else
945 static const unsigned char exporterlabel[] = "exporter";
946#endif
b38ede80
TT
947 unsigned char exportsecret[EVP_MAX_MD_SIZE];
948 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
949 const EVP_MD *md;
950 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
951 unsigned int hashsize, datalen;
952 int ret = 0;
953 const SSL_CIPHER *sslcipher;
954
955 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
956 goto err;
957
958 if (!s->server && s->max_early_data > 0
959 && s->session->ext.max_early_data == 0)
960 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
961 else
962 sslcipher = SSL_SESSION_get0_cipher(s->session);
963
c8f6c28a 964 md = ssl_md(s->ctx, sslcipher->algorithm2);
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TT
965
966 /*
967 * Calculate the hash value and store it in |data|. The reason why
968 * the empty string is used is that the definition of TLS-Exporter
969 * is like so:
970 *
971 * TLS-Exporter(label, context_value, key_length) =
972 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
973 * "exporter", Hash(context_value), key_length)
974 *
975 * Derive-Secret(Secret, Label, Messages) =
976 * HKDF-Expand-Label(Secret, Label,
977 * Transcript-Hash(Messages), Hash.length)
978 *
979 * Here Transcript-Hash is the cipher suite hash algorithm.
980 */
981 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
982 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
983 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
984 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
985 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
986 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
987 (const unsigned char *)label, llen,
0fb2815b 988 data, datalen, exportsecret, hashsize, 0)
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TT
989 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
990 sizeof(exporterlabel) - 1, hash, hashsize,
0fb2815b 991 out, olen, 0))
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992 goto err;
993
994 ret = 1;
995 err:
996 EVP_MD_CTX_free(ctx);
997 return ret;
998}