1 /*
2 * Copyright 2016-2025 The OpenSSL Project Authors. All Rights Reserved.
3 *
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
8 */
9
10 #include <stdlib.h>
11 #include "ssl_local.h"
12 #include "internal/ktls.h"
13 #include "record/record_local.h"
14 #include "internal/cryptlib.h"
15 #include "internal/ssl_unwrap.h"
16 #include <openssl/evp.h>
17 #include <openssl/kdf.h>
18 #include <openssl/core_names.h>
19
20 #define TLS13_MAX_LABEL_LEN 249
21
22 /* ASCII: "tls13 ", in hex for EBCDIC compatibility */
23 static const unsigned char label_prefix[] = "\x74\x6C\x73\x31\x33\x20";
24
25 /*
26 * Given a |secret|; a |label| of length |labellen|; and |data| of length
27 * |datalen| (e.g. typically a hash of the handshake messages), derive a new
28 * secret |outlen| bytes long and store it in the location pointed to be |out|.
29 * The |data| value may be zero length. Any errors will be treated as fatal if
30 * |fatal| is set. Returns 1 on success 0 on failure.
31 * If |raise_error| is set, ERR_raise is called on failure.
32 */
tls13_hkdf_expand_ex(OSSL_LIB_CTX * libctx,const char * propq,const EVP_MD * md,const unsigned char * secret,const unsigned char * label,size_t labellen,const unsigned char * data,size_t datalen,unsigned char * out,size_t outlen,int raise_error)33 int tls13_hkdf_expand_ex(OSSL_LIB_CTX *libctx, const char *propq,
34 const EVP_MD *md,
35 const unsigned char *secret,
36 const unsigned char *label, size_t labellen,
37 const unsigned char *data, size_t datalen,
38 unsigned char *out, size_t outlen, int raise_error)
39 {
40 EVP_KDF *kdf = EVP_KDF_fetch(libctx, OSSL_KDF_NAME_TLS1_3_KDF, propq);
41 EVP_KDF_CTX *kctx;
42 OSSL_PARAM params[7], *p = params;
43 int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY;
44 const char *mdname = EVP_MD_get0_name(md);
45 int ret;
46 size_t hashlen;
47
48 kctx = EVP_KDF_CTX_new(kdf);
49 EVP_KDF_free(kdf);
50 if (kctx == NULL)
51 return 0;
52
53 if (labellen > TLS13_MAX_LABEL_LEN) {
54 if (raise_error)
55 /*
56 * Probably we have been called from SSL_export_keying_material(),
57 * or SSL_export_keying_material_early().
58 */
59 ERR_raise(ERR_LIB_SSL, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
60
61 EVP_KDF_CTX_free(kctx);
62 return 0;
63 }
64
65 if ((ret = EVP_MD_get_size(md)) <= 0) {
66 EVP_KDF_CTX_free(kctx);
67 if (raise_error)
68 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
69 return 0;
70 }
71 hashlen = (size_t)ret;
72
73 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
74 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
75 (char *)mdname, 0);
76 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
77 (unsigned char *)secret, hashlen);
78 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
79 (unsigned char *)label_prefix,
80 sizeof(label_prefix) - 1);
81 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
82 (unsigned char *)label, labellen);
83 if (data != NULL)
84 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_DATA,
85 (unsigned char *)data,
86 datalen);
87 *p++ = OSSL_PARAM_construct_end();
88
89 ret = EVP_KDF_derive(kctx, out, outlen, params) <= 0;
90 EVP_KDF_CTX_free(kctx);
91
92 if (ret != 0) {
93 if (raise_error)
94 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
95 }
96
97 return ret == 0;
98 }
99
tls13_hkdf_expand(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,const unsigned char * label,size_t labellen,const unsigned char * data,size_t datalen,unsigned char * out,size_t outlen,int fatal)100 int tls13_hkdf_expand(SSL_CONNECTION *s, const EVP_MD *md,
101 const unsigned char *secret,
102 const unsigned char *label, size_t labellen,
103 const unsigned char *data, size_t datalen,
104 unsigned char *out, size_t outlen, int fatal)
105 {
106 int ret;
107 SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
108
109 ret = tls13_hkdf_expand_ex(sctx->libctx, sctx->propq, md,
110 secret, label, labellen, data, datalen,
111 out, outlen, !fatal);
112 if (ret == 0 && fatal)
113 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
114
115 return ret;
116 }
117
118 /*
119 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
120 * success 0 on failure.
121 */
tls13_derive_key(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,unsigned char * key,size_t keylen)122 int tls13_derive_key(SSL_CONNECTION *s, const EVP_MD *md,
123 const unsigned char *secret,
124 unsigned char *key, size_t keylen)
125 {
126 /* ASCII: "key", in hex for EBCDIC compatibility */
127 static const unsigned char keylabel[] = "\x6B\x65\x79";
128
129 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
130 NULL, 0, key, keylen, 1);
131 }
132
133 /*
134 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
135 * success 0 on failure.
136 */
tls13_derive_iv(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,unsigned char * iv,size_t ivlen)137 int tls13_derive_iv(SSL_CONNECTION *s, const EVP_MD *md,
138 const unsigned char *secret,
139 unsigned char *iv, size_t ivlen)
140 {
141 /* ASCII: "iv", in hex for EBCDIC compatibility */
142 static const unsigned char ivlabel[] = "\x69\x76";
143
144 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
145 NULL, 0, iv, ivlen, 1);
146 }
147
tls13_derive_finishedkey(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,unsigned char * fin,size_t finlen)148 int tls13_derive_finishedkey(SSL_CONNECTION *s, const EVP_MD *md,
149 const unsigned char *secret,
150 unsigned char *fin, size_t finlen)
151 {
152 /* ASCII: "finished", in hex for EBCDIC compatibility */
153 static const unsigned char finishedlabel[] = "\x66\x69\x6E\x69\x73\x68\x65\x64";
154
155 return tls13_hkdf_expand(s, md, secret, finishedlabel,
156 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
157 }
158
159 /*
160 * Given the previous secret |prevsecret| and a new input secret |insecret| of
161 * length |insecretlen|, generate a new secret and store it in the location
162 * pointed to by |outsecret|. Returns 1 on success 0 on failure.
163 */
tls13_generate_secret(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * prevsecret,const unsigned char * insecret,size_t insecretlen,unsigned char * outsecret)164 int tls13_generate_secret(SSL_CONNECTION *s, const EVP_MD *md,
165 const unsigned char *prevsecret,
166 const unsigned char *insecret,
167 size_t insecretlen,
168 unsigned char *outsecret)
169 {
170 size_t mdlen;
171 int mdleni;
172 int ret;
173 EVP_KDF *kdf;
174 EVP_KDF_CTX *kctx;
175 OSSL_PARAM params[7], *p = params;
176 int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
177 const char *mdname = EVP_MD_get0_name(md);
178 /* ASCII: "derived", in hex for EBCDIC compatibility */
179 static const char derived_secret_label[] = "\x64\x65\x72\x69\x76\x65\x64";
180 SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
181
182 kdf = EVP_KDF_fetch(sctx->libctx, OSSL_KDF_NAME_TLS1_3_KDF, sctx->propq);
183 kctx = EVP_KDF_CTX_new(kdf);
184 EVP_KDF_free(kdf);
185 if (kctx == NULL) {
186 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
187 return 0;
188 }
189
190 mdleni = EVP_MD_get_size(md);
191 /* Ensure cast to size_t is safe */
192 if (!ossl_assert(mdleni > 0)) {
193 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
194 EVP_KDF_CTX_free(kctx);
195 return 0;
196 }
197 mdlen = (size_t)mdleni;
198
199 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
200 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
201 (char *)mdname, 0);
202 if (insecret != NULL)
203 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
204 (unsigned char *)insecret,
205 insecretlen);
206 if (prevsecret != NULL)
207 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
208 (unsigned char *)prevsecret, mdlen);
209 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
210 (unsigned char *)label_prefix,
211 sizeof(label_prefix) - 1);
212 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
213 (unsigned char *)derived_secret_label,
214 sizeof(derived_secret_label) - 1);
215 *p++ = OSSL_PARAM_construct_end();
216
217 ret = EVP_KDF_derive(kctx, outsecret, mdlen, params) <= 0;
218
219 if (ret != 0)
220 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
221
222 EVP_KDF_CTX_free(kctx);
223 return ret == 0;
224 }
225
226 /*
227 * Given an input secret |insecret| of length |insecretlen| generate the
228 * handshake secret. This requires the early secret to already have been
229 * generated. Returns 1 on success 0 on failure.
230 */
tls13_generate_handshake_secret(SSL_CONNECTION * s,const unsigned char * insecret,size_t insecretlen)231 int tls13_generate_handshake_secret(SSL_CONNECTION *s,
232 const unsigned char *insecret,
233 size_t insecretlen)
234 {
235 /* Calls SSLfatal() if required */
236 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
237 insecret, insecretlen,
238 (unsigned char *)&s->handshake_secret);
239 }
240
241 /*
242 * Given the handshake secret |prev| of length |prevlen| generate the master
243 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
244 * failure.
245 */
tls13_generate_master_secret(SSL_CONNECTION * s,unsigned char * out,unsigned char * prev,size_t prevlen,size_t * secret_size)246 int tls13_generate_master_secret(SSL_CONNECTION *s, unsigned char *out,
247 unsigned char *prev, size_t prevlen,
248 size_t *secret_size)
249 {
250 const EVP_MD *md = ssl_handshake_md(s);
251 int md_size;
252
253 md_size = EVP_MD_get_size(md);
254 if (md_size <= 0) {
255 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
256 return 0;
257 }
258 *secret_size = (size_t)md_size;
259 /* Calls SSLfatal() if required */
260 return tls13_generate_secret(s, md, prev, NULL, 0, out);
261 }
262
263 /*
264 * Generates the mac for the Finished message. Returns the length of the MAC or
265 * 0 on error.
266 */
tls13_final_finish_mac(SSL_CONNECTION * s,const char * str,size_t slen,unsigned char * out)267 size_t tls13_final_finish_mac(SSL_CONNECTION *s, const char *str, size_t slen,
268 unsigned char *out)
269 {
270 const EVP_MD *md = ssl_handshake_md(s);
271 const char *mdname = EVP_MD_get0_name(md);
272 unsigned char hash[EVP_MAX_MD_SIZE];
273 unsigned char finsecret[EVP_MAX_MD_SIZE];
274 unsigned char *key = NULL;
275 size_t len = 0, hashlen;
276 OSSL_PARAM params[2], *p = params;
277 SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
278
279 if (md == NULL)
280 return 0;
281
282 /* Safe to cast away const here since we're not "getting" any data */
283 if (sctx->propq != NULL)
284 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
285 (char *)sctx->propq,
286 0);
287 *p = OSSL_PARAM_construct_end();
288
289 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
290 /* SSLfatal() already called */
291 goto err;
292 }
293
294 if (str == SSL_CONNECTION_GET_SSL(s)->method->ssl3_enc->server_finished_label) {
295 key = s->server_finished_secret;
296 } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
297 key = s->client_finished_secret;
298 } else {
299 if (!tls13_derive_finishedkey(s, md,
300 s->client_app_traffic_secret,
301 finsecret, hashlen))
302 goto err;
303 key = finsecret;
304 }
305
306 if (!EVP_Q_mac(sctx->libctx, "HMAC", sctx->propq, mdname,
307 params, key, hashlen, hash, hashlen,
308 /* outsize as per sizeof(peer_finish_md) */
309 out, EVP_MAX_MD_SIZE * 2, &len)) {
310 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
311 goto err;
312 }
313
314 err:
315 OPENSSL_cleanse(finsecret, sizeof(finsecret));
316 return len;
317 }
318
319 /*
320 * There isn't really a key block in TLSv1.3, but we still need this function
321 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
322 */
tls13_setup_key_block(SSL_CONNECTION * s)323 int tls13_setup_key_block(SSL_CONNECTION *s)
324 {
325 const EVP_CIPHER *c;
326 const EVP_MD *hash;
327 int mac_type = NID_undef;
328 size_t mac_secret_size = 0;
329
330 s->session->cipher = s->s3.tmp.new_cipher;
331 if (!ssl_cipher_get_evp(SSL_CONNECTION_GET_CTX(s), s->session, &c, &hash,
332 &mac_type, &mac_secret_size, NULL, 0)) {
333 /* Error is already recorded */
334 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
335 return 0;
336 }
337
338 ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
339 s->s3.tmp.new_sym_enc = c;
340 ssl_evp_md_free(s->s3.tmp.new_hash);
341 s->s3.tmp.new_hash = hash;
342 s->s3.tmp.new_mac_pkey_type = mac_type;
343 s->s3.tmp.new_mac_secret_size = mac_secret_size;
344
345 return 1;
346 }
347
derive_secret_key_and_iv(SSL_CONNECTION * s,const EVP_MD * md,const EVP_CIPHER * ciph,int mac_type,const EVP_MD * mac_md,const unsigned char * insecret,const unsigned char * hash,const unsigned char * label,size_t labellen,unsigned char * secret,unsigned char * key,size_t * keylen,unsigned char ** iv,size_t * ivlen,size_t * taglen)348 static int derive_secret_key_and_iv(SSL_CONNECTION *s, const EVP_MD *md,
349 const EVP_CIPHER *ciph,
350 int mac_type,
351 const EVP_MD *mac_md,
352 const unsigned char *insecret,
353 const unsigned char *hash,
354 const unsigned char *label,
355 size_t labellen, unsigned char *secret,
356 unsigned char *key, size_t *keylen,
357 unsigned char **iv, size_t *ivlen,
358 size_t *taglen)
359 {
360 int hashleni = EVP_MD_get_size(md);
361 size_t hashlen;
362 int mode, mac_mdleni;
363
364 /* Ensure cast to size_t is safe */
365 if (!ossl_assert(hashleni > 0)) {
366 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
367 return 0;
368 }
369 hashlen = (size_t)hashleni;
370
371 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
372 secret, hashlen, 1)) {
373 /* SSLfatal() already called */
374 return 0;
375 }
376
377 /* if ciph is NULL cipher, then use new_hash to calculate keylen */
378 if (EVP_CIPHER_is_a(ciph, "NULL")
379 && mac_md != NULL
380 && mac_type == NID_hmac) {
381 mac_mdleni = EVP_MD_get_size(mac_md);
382
383 if (mac_mdleni <= 0) {
384 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
385 return 0;
386 }
387 *ivlen = *taglen = (size_t)mac_mdleni;
388 *keylen = s->s3.tmp.new_mac_secret_size;
389 } else {
390
391 *keylen = EVP_CIPHER_get_key_length(ciph);
392
393 mode = EVP_CIPHER_get_mode(ciph);
394 if (mode == EVP_CIPH_CCM_MODE) {
395 uint32_t algenc;
396
397 *ivlen = EVP_CCM_TLS_IV_LEN;
398 if (s->s3.tmp.new_cipher != NULL) {
399 algenc = s->s3.tmp.new_cipher->algorithm_enc;
400 } else if (s->session->cipher != NULL) {
401 /* We've not selected a cipher yet - we must be doing early data */
402 algenc = s->session->cipher->algorithm_enc;
403 } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
404 /* We must be doing early data with out-of-band PSK */
405 algenc = s->psksession->cipher->algorithm_enc;
406 } else {
407 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
408 return 0;
409 }
410 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
411 *taglen = EVP_CCM8_TLS_TAG_LEN;
412 else
413 *taglen = EVP_CCM_TLS_TAG_LEN;
414 } else {
415 int iivlen;
416
417 if (mode == EVP_CIPH_GCM_MODE) {
418 *taglen = EVP_GCM_TLS_TAG_LEN;
419 } else {
420 /* CHACHA20P-POLY1305 */
421 *taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
422 }
423 iivlen = EVP_CIPHER_get_iv_length(ciph);
424 if (iivlen < 0) {
425 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
426 return 0;
427 }
428 *ivlen = iivlen;
429 }
430 }
431
432 if (*ivlen > EVP_MAX_IV_LENGTH) {
433 *iv = OPENSSL_malloc(*ivlen);
434 if (*iv == NULL) {
435 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
436 return 0;
437 }
438 }
439
440 if (!tls13_derive_key(s, md, secret, key, *keylen)
441 || !tls13_derive_iv(s, md, secret, *iv, *ivlen)) {
442 /* SSLfatal() already called */
443 return 0;
444 }
445
446 return 1;
447 }
448
tls13_store_hash(SSL_CONNECTION * s,unsigned char * hash,size_t len)449 static int tls13_store_hash(SSL_CONNECTION *s, unsigned char *hash, size_t len)
450 {
451 size_t hashlen;
452
453 if (!ssl3_digest_cached_records(s, 1)
454 || !ssl_handshake_hash(s, hash, len, &hashlen)) {
455 /* SSLfatal() already called */;
456 return 0;
457 }
458
459 return 1;
460 }
461
tls13_store_handshake_traffic_hash(SSL_CONNECTION * s)462 int tls13_store_handshake_traffic_hash(SSL_CONNECTION *s)
463 {
464 return tls13_store_hash(s, s->handshake_traffic_hash,
465 sizeof(s->handshake_traffic_hash));
466 }
467
tls13_store_server_finished_hash(SSL_CONNECTION * s)468 int tls13_store_server_finished_hash(SSL_CONNECTION *s)
469 {
470 return tls13_store_hash(s, s->server_finished_hash,
471 sizeof(s->server_finished_hash));
472 }
473
tls13_change_cipher_state(SSL_CONNECTION * s,int which)474 int tls13_change_cipher_state(SSL_CONNECTION *s, int which)
475 {
476 /* ASCII: "c e traffic", in hex for EBCDIC compatibility */
477 static const unsigned char client_early_traffic[] = "\x63\x20\x65\x20\x74\x72\x61\x66\x66\x69\x63";
478 /* ASCII: "c hs traffic", in hex for EBCDIC compatibility */
479 static const unsigned char client_handshake_traffic[] = "\x63\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
480 /* ASCII: "c ap traffic", in hex for EBCDIC compatibility */
481 static const unsigned char client_application_traffic[] = "\x63\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
482 /* ASCII: "s hs traffic", in hex for EBCDIC compatibility */
483 static const unsigned char server_handshake_traffic[] = "\x73\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
484 /* ASCII: "s ap traffic", in hex for EBCDIC compatibility */
485 static const unsigned char server_application_traffic[] = "\x73\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
486 /* ASCII: "exp master", in hex for EBCDIC compatibility */
487 static const unsigned char exporter_master_secret[] = "\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
488 /* ASCII: "res master", in hex for EBCDIC compatibility */
489 static const unsigned char resumption_master_secret[] = "\x72\x65\x73\x20\x6D\x61\x73\x74\x65\x72";
490 /* ASCII: "e exp master", in hex for EBCDIC compatibility */
491 static const unsigned char early_exporter_master_secret[] = "\x65\x20\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
492 unsigned char iv_intern[EVP_MAX_IV_LENGTH];
493 unsigned char *iv = iv_intern;
494 unsigned char key[EVP_MAX_KEY_LENGTH];
495 unsigned char secret[EVP_MAX_MD_SIZE];
496 unsigned char hashval[EVP_MAX_MD_SIZE];
497 unsigned char *hash = hashval;
498 unsigned char *insecret;
499 unsigned char *finsecret = NULL;
500 const char *log_label = NULL;
501 int finsecretlen = 0;
502 const unsigned char *label;
503 size_t labellen, hashlen = 0;
504 int ret = 0;
505 const EVP_MD *md = NULL, *mac_md = NULL;
506 const EVP_CIPHER *cipher = NULL;
507 int mac_pkey_type = NID_undef;
508 SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
509 size_t keylen, ivlen = EVP_MAX_IV_LENGTH, taglen;
510 int level;
511 int direction = (which & SSL3_CC_READ) != 0 ? OSSL_RECORD_DIRECTION_READ
512 : OSSL_RECORD_DIRECTION_WRITE;
513
514 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
515 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
516 if ((which & SSL3_CC_EARLY) != 0) {
517 EVP_MD_CTX *mdctx = NULL;
518 long handlen;
519 void *hdata;
520 unsigned int hashlenui;
521 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
522
523 insecret = s->early_secret;
524 label = client_early_traffic;
525 labellen = sizeof(client_early_traffic) - 1;
526 log_label = CLIENT_EARLY_LABEL;
527
528 handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
529 if (handlen <= 0) {
530 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
531 goto err;
532 }
533
534 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
535 && s->max_early_data > 0
536 && s->session->ext.max_early_data == 0) {
537 /*
538 * If we are attempting to send early data, and we've decided to
539 * actually do it but max_early_data in s->session is 0 then we
540 * must be using an external PSK.
541 */
542 if (!ossl_assert(s->psksession != NULL
543 && s->max_early_data == s->psksession->ext.max_early_data)) {
544 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
545 goto err;
546 }
547 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
548 }
549 if (sslcipher == NULL) {
550 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
551 goto err;
552 }
553
554 /*
555 * This ups the ref count on cipher so we better make sure we free
556 * it again
557 */
558 if (!ssl_cipher_get_evp_cipher(sctx, sslcipher, &cipher)) {
559 /* Error is already recorded */
560 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
561 goto err;
562 }
563
564 if (((EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) == 0)
565 && (!ssl_cipher_get_evp_md_mac(sctx, sslcipher, &mac_md,
566 &mac_pkey_type, NULL))) {
567 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
568 goto err;
569 }
570
571 /*
572 * We need to calculate the handshake digest using the digest from
573 * the session. We haven't yet selected our ciphersuite so we can't
574 * use ssl_handshake_md().
575 */
576 mdctx = EVP_MD_CTX_new();
577 if (mdctx == NULL) {
578 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
579 goto err;
580 }
581
582 md = ssl_md(sctx, sslcipher->algorithm2);
583 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
584 || !EVP_DigestUpdate(mdctx, hdata, handlen)
585 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
586 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
587 EVP_MD_CTX_free(mdctx);
588 goto err;
589 }
590 hashlen = hashlenui;
591 EVP_MD_CTX_free(mdctx);
592
593 if (!tls13_hkdf_expand(s, md, insecret,
594 early_exporter_master_secret,
595 sizeof(early_exporter_master_secret) - 1,
596 hashval, hashlen,
597 s->early_exporter_master_secret, hashlen,
598 1)) {
599 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
600 goto err;
601 }
602
603 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
604 s->early_exporter_master_secret, hashlen)) {
605 /* SSLfatal() already called */
606 goto err;
607 }
608 } else if (which & SSL3_CC_HANDSHAKE) {
609 insecret = s->handshake_secret;
610 finsecret = s->client_finished_secret;
611 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
612 if (finsecretlen <= 0) {
613 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
614 goto err;
615 }
616 label = client_handshake_traffic;
617 labellen = sizeof(client_handshake_traffic) - 1;
618 log_label = CLIENT_HANDSHAKE_LABEL;
619 /*
620 * The handshake hash used for the server read/client write handshake
621 * traffic secret is the same as the hash for the server
622 * write/client read handshake traffic secret. However, if we
623 * processed early data then we delay changing the server
624 * read/client write cipher state until later, and the handshake
625 * hashes have moved on. Therefore we use the value saved earlier
626 * when we did the server write/client read change cipher state.
627 */
628 hash = s->handshake_traffic_hash;
629 } else {
630 insecret = s->master_secret;
631 label = client_application_traffic;
632 labellen = sizeof(client_application_traffic) - 1;
633 log_label = CLIENT_APPLICATION_LABEL;
634 /*
635 * For this we only use the handshake hashes up until the server
636 * Finished hash. We do not include the client's Finished, which is
637 * what ssl_handshake_hash() would give us. Instead we use the
638 * previously saved value.
639 */
640 hash = s->server_finished_hash;
641 }
642 } else {
643 /* Early data never applies to client-read/server-write */
644 if (which & SSL3_CC_HANDSHAKE) {
645 insecret = s->handshake_secret;
646 finsecret = s->server_finished_secret;
647 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
648 if (finsecretlen <= 0) {
649 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
650 goto err;
651 }
652 label = server_handshake_traffic;
653 labellen = sizeof(server_handshake_traffic) - 1;
654 log_label = SERVER_HANDSHAKE_LABEL;
655 } else {
656 insecret = s->master_secret;
657 label = server_application_traffic;
658 labellen = sizeof(server_application_traffic) - 1;
659 log_label = SERVER_APPLICATION_LABEL;
660 hash = s->server_finished_hash;
661 }
662 }
663
664 if ((which & SSL3_CC_EARLY) == 0) {
665 md = ssl_handshake_md(s);
666 cipher = s->s3.tmp.new_sym_enc;
667 mac_md = s->s3.tmp.new_hash;
668 mac_pkey_type = s->s3.tmp.new_mac_pkey_type;
669 if (!ssl3_digest_cached_records(s, 1)
670 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
671 /* SSLfatal() already called */;
672 goto err;
673 }
674 }
675
676 if (label == client_application_traffic) {
677 /*
678 * We also create the resumption master secret, but this time use the
679 * hash for the whole handshake including the Client Finished
680 */
681 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
682 resumption_master_secret,
683 sizeof(resumption_master_secret) - 1,
684 hashval, hashlen, s->resumption_master_secret,
685 hashlen, 1)) {
686 /* SSLfatal() already called */
687 goto err;
688 }
689 }
690
691 /* check whether cipher is known */
692 if (!ossl_assert(cipher != NULL))
693 goto err;
694
695 if (!derive_secret_key_and_iv(s, md, cipher, mac_pkey_type, mac_md,
696 insecret, hash, label, labellen, secret, key,
697 &keylen, &iv, &ivlen, &taglen)) {
698 /* SSLfatal() already called */
699 goto err;
700 }
701
702 if (label == server_application_traffic) {
703 memcpy(s->server_app_traffic_secret, secret, hashlen);
704 /* Now we create the exporter master secret */
705 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
706 exporter_master_secret,
707 sizeof(exporter_master_secret) - 1,
708 hash, hashlen, s->exporter_master_secret,
709 hashlen, 1)) {
710 /* SSLfatal() already called */
711 goto err;
712 }
713
714 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
715 hashlen)) {
716 /* SSLfatal() already called */
717 goto err;
718 }
719 } else if (label == client_application_traffic)
720 memcpy(s->client_app_traffic_secret, secret, hashlen);
721
722 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
723 /* SSLfatal() already called */
724 goto err;
725 }
726
727 if (finsecret != NULL
728 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
729 finsecret, (size_t)finsecretlen)) {
730 /* SSLfatal() already called */
731 goto err;
732 }
733
734 if ((which & SSL3_CC_WRITE) != 0) {
735 if (!s->server && label == client_early_traffic)
736 s->rlayer.wrlmethod->set_plain_alerts(s->rlayer.wrl, 1);
737 else
738 s->rlayer.wrlmethod->set_plain_alerts(s->rlayer.wrl, 0);
739 }
740
741 level = (which & SSL3_CC_EARLY) != 0
742 ? OSSL_RECORD_PROTECTION_LEVEL_EARLY
743 : ((which & SSL3_CC_HANDSHAKE) != 0
744 ? OSSL_RECORD_PROTECTION_LEVEL_HANDSHAKE
745 : OSSL_RECORD_PROTECTION_LEVEL_APPLICATION);
746
747 if (!ssl_set_new_record_layer(s, s->version,
748 direction,
749 level, secret, hashlen, key, keylen, iv,
750 ivlen, NULL, 0, cipher, taglen,
751 mac_pkey_type, mac_md, NULL, md)) {
752 /* SSLfatal already called */
753 goto err;
754 }
755
756 ret = 1;
757 err:
758 if ((which & SSL3_CC_EARLY) != 0) {
759 /* We up-refed this so now we need to down ref */
760 if ((EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) == 0)
761 ssl_evp_md_free(mac_md);
762 ssl_evp_cipher_free(cipher);
763 }
764 OPENSSL_cleanse(key, sizeof(key));
765 OPENSSL_cleanse(secret, sizeof(secret));
766 if (iv != iv_intern)
767 OPENSSL_free(iv);
768 return ret;
769 }
770
tls13_update_key(SSL_CONNECTION * s,int sending)771 int tls13_update_key(SSL_CONNECTION *s, int sending)
772 {
773 /* ASCII: "traffic upd", in hex for EBCDIC compatibility */
774 static const unsigned char application_traffic[] = "\x74\x72\x61\x66\x66\x69\x63\x20\x75\x70\x64";
775 const EVP_MD *md = ssl_handshake_md(s);
776 size_t hashlen;
777 unsigned char key[EVP_MAX_KEY_LENGTH];
778 unsigned char *insecret;
779 unsigned char secret[EVP_MAX_MD_SIZE];
780 char *log_label;
781 size_t keylen, ivlen, taglen;
782 int ret = 0, l;
783 int direction = sending ? OSSL_RECORD_DIRECTION_WRITE
784 : OSSL_RECORD_DIRECTION_READ;
785 unsigned char iv_intern[EVP_MAX_IV_LENGTH];
786 unsigned char *iv = iv_intern;
787
788 if ((l = EVP_MD_get_size(md)) <= 0) {
789 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
790 return 0;
791 }
792 hashlen = (size_t)l;
793
794 if (s->server == sending)
795 insecret = s->server_app_traffic_secret;
796 else
797 insecret = s->client_app_traffic_secret;
798
799 if (!derive_secret_key_and_iv(s, md,
800 s->s3.tmp.new_sym_enc,
801 s->s3.tmp.new_mac_pkey_type, s->s3.tmp.new_hash,
802 insecret, NULL,
803 application_traffic,
804 sizeof(application_traffic) - 1, secret, key,
805 &keylen, &iv, &ivlen, &taglen)) {
806 /* SSLfatal() already called */
807 goto err;
808 }
809
810 memcpy(insecret, secret, hashlen);
811
812 if (!ssl_set_new_record_layer(s, s->version,
813 direction,
814 OSSL_RECORD_PROTECTION_LEVEL_APPLICATION,
815 insecret, hashlen, key, keylen, iv, ivlen, NULL, 0,
816 s->s3.tmp.new_sym_enc, taglen, NID_undef, NULL,
817 NULL, md)) {
818 /* SSLfatal already called */
819 goto err;
820 }
821
822 /* Call Key log on successful traffic secret update */
823 log_label = s->server == sending ? SERVER_APPLICATION_N_LABEL : CLIENT_APPLICATION_N_LABEL;
824 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
825 /* SSLfatal() already called */
826 goto err;
827 }
828 ret = 1;
829 err:
830 OPENSSL_cleanse(key, sizeof(key));
831 OPENSSL_cleanse(secret, sizeof(secret));
832 if (iv != iv_intern)
833 OPENSSL_free(iv);
834 return ret;
835 }
836
tls13_alert_code(int code)837 int tls13_alert_code(int code)
838 {
839 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
840 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
841 return code;
842
843 return tls1_alert_code(code);
844 }
845
tls13_export_keying_material(SSL_CONNECTION * s,unsigned char * out,size_t olen,const char * label,size_t llen,const unsigned char * context,size_t contextlen,int use_context)846 int tls13_export_keying_material(SSL_CONNECTION *s,
847 unsigned char *out, size_t olen,
848 const char *label, size_t llen,
849 const unsigned char *context,
850 size_t contextlen, int use_context)
851 {
852 unsigned char exportsecret[EVP_MAX_MD_SIZE];
853 /* ASCII: "exporter", in hex for EBCDIC compatibility */
854 static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
855 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
856 const EVP_MD *md = ssl_handshake_md(s);
857 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
858 unsigned int hashsize, datalen;
859 int ret = 0;
860
861 if (ctx == NULL || md == NULL || !ossl_statem_export_allowed(s))
862 goto err;
863
864 if (!use_context)
865 contextlen = 0;
866
867 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
868 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
869 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
870 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
871 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
872 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
873 (const unsigned char *)label, llen,
874 data, datalen, exportsecret, hashsize, 0)
875 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
876 sizeof(exporterlabel) - 1, hash, hashsize,
877 out, olen, 0))
878 goto err;
879
880 ret = 1;
881 err:
882 EVP_MD_CTX_free(ctx);
883 return ret;
884 }
885
tls13_export_keying_material_early(SSL_CONNECTION * s,unsigned char * out,size_t olen,const char * label,size_t llen,const unsigned char * context,size_t contextlen)886 int tls13_export_keying_material_early(SSL_CONNECTION *s,
887 unsigned char *out, size_t olen,
888 const char *label, size_t llen,
889 const unsigned char *context,
890 size_t contextlen)
891 {
892 /* ASCII: "exporter", in hex for EBCDIC compatibility */
893 static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
894 unsigned char exportsecret[EVP_MAX_MD_SIZE];
895 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
896 const EVP_MD *md;
897 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
898 unsigned int hashsize, datalen;
899 int ret = 0;
900 const SSL_CIPHER *sslcipher;
901
902 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
903 goto err;
904
905 if (!s->server && s->max_early_data > 0
906 && s->session->ext.max_early_data == 0)
907 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
908 else
909 sslcipher = SSL_SESSION_get0_cipher(s->session);
910
911 md = ssl_md(SSL_CONNECTION_GET_CTX(s), sslcipher->algorithm2);
912
913 /*
914 * Calculate the hash value and store it in |data|. The reason why
915 * the empty string is used is that the definition of TLS-Exporter
916 * is like so:
917 *
918 * TLS-Exporter(label, context_value, key_length) =
919 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
920 * "exporter", Hash(context_value), key_length)
921 *
922 * Derive-Secret(Secret, Label, Messages) =
923 * HKDF-Expand-Label(Secret, Label,
924 * Transcript-Hash(Messages), Hash.length)
925 *
926 * Here Transcript-Hash is the cipher suite hash algorithm.
927 */
928 if (md == NULL
929 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
930 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
931 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
932 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
933 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
934 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
935 (const unsigned char *)label, llen,
936 data, datalen, exportsecret, hashsize, 0)
937 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
938 sizeof(exporterlabel) - 1, hash, hashsize,
939 out, olen, 0))
940 goto err;
941
942 ret = 1;
943 err:
944 EVP_MD_CTX_free(ctx);
945 return ret;
946 }
947