1 /*
2 * Copyright 2016-2024 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 <openssl/evp.h>
16 #include <openssl/kdf.h>
17 #include <openssl/core_names.h>
18
19 #define TLS13_MAX_LABEL_LEN 249
20
21 /* ASCII: "tls13 ", in hex for EBCDIC compatibility */
22 static const unsigned char label_prefix[] = "\x74\x6C\x73\x31\x33\x20";
23
24 /*
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.
30 * If |raise_error| is set, ERR_raise is called on failure.
31 */
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)32 int tls13_hkdf_expand_ex(OSSL_LIB_CTX *libctx, const char *propq,
33 const EVP_MD *md,
34 const unsigned char *secret,
35 const unsigned char *label, size_t labellen,
36 const unsigned char *data, size_t datalen,
37 unsigned char *out, size_t outlen, int raise_error)
38 {
39 EVP_KDF *kdf = EVP_KDF_fetch(libctx, OSSL_KDF_NAME_TLS1_3_KDF, propq);
40 EVP_KDF_CTX *kctx;
41 OSSL_PARAM params[7], *p = params;
42 int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY;
43 const char *mdname = EVP_MD_get0_name(md);
44 int ret;
45 size_t hashlen;
46
47 kctx = EVP_KDF_CTX_new(kdf);
48 EVP_KDF_free(kdf);
49 if (kctx == NULL)
50 return 0;
51
52 if (labellen > TLS13_MAX_LABEL_LEN) {
53 if (raise_error)
54 /*
55 * Probably we have been called from SSL_export_keying_material(),
56 * or SSL_export_keying_material_early().
57 */
58 ERR_raise(ERR_LIB_SSL, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
59
60 EVP_KDF_CTX_free(kctx);
61 return 0;
62 }
63
64 if ((ret = EVP_MD_get_size(md)) <= 0) {
65 EVP_KDF_CTX_free(kctx);
66 if (raise_error)
67 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
68 return 0;
69 }
70 hashlen = (size_t)ret;
71
72 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
73 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
74 (char *)mdname, 0);
75 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
76 (unsigned char *)secret, hashlen);
77 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
78 (unsigned char *)label_prefix,
79 sizeof(label_prefix) - 1);
80 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
81 (unsigned char *)label, labellen);
82 if (data != NULL)
83 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_DATA,
84 (unsigned char *)data,
85 datalen);
86 *p++ = OSSL_PARAM_construct_end();
87
88 ret = EVP_KDF_derive(kctx, out, outlen, params) <= 0;
89 EVP_KDF_CTX_free(kctx);
90
91 if (ret != 0) {
92 if (raise_error)
93 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
94 }
95
96 return ret == 0;
97 }
98
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)99 int tls13_hkdf_expand(SSL_CONNECTION *s, const EVP_MD *md,
100 const unsigned char *secret,
101 const unsigned char *label, size_t labellen,
102 const unsigned char *data, size_t datalen,
103 unsigned char *out, size_t outlen, int fatal)
104 {
105 int ret;
106 SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
107
108 ret = tls13_hkdf_expand_ex(sctx->libctx, sctx->propq, md,
109 secret, label, labellen, data, datalen,
110 out, outlen, !fatal);
111 if (ret == 0 && fatal)
112 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
113
114 return ret;
115 }
116
117 /*
118 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
119 * success 0 on failure.
120 */
tls13_derive_key(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,unsigned char * key,size_t keylen)121 int tls13_derive_key(SSL_CONNECTION *s, const EVP_MD *md,
122 const unsigned char *secret,
123 unsigned char *key, size_t keylen)
124 {
125 /* ASCII: "key", in hex for EBCDIC compatibility */
126 static const unsigned char keylabel[] = "\x6B\x65\x79";
127
128 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
129 NULL, 0, key, keylen, 1);
130 }
131
132 /*
133 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
134 * success 0 on failure.
135 */
tls13_derive_iv(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,unsigned char * iv,size_t ivlen)136 int tls13_derive_iv(SSL_CONNECTION *s, const EVP_MD *md,
137 const unsigned char *secret,
138 unsigned char *iv, size_t ivlen)
139 {
140 /* ASCII: "iv", in hex for EBCDIC compatibility */
141 static const unsigned char ivlabel[] = "\x69\x76";
142
143 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
144 NULL, 0, iv, ivlen, 1);
145 }
146
tls13_derive_finishedkey(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,unsigned char * fin,size_t finlen)147 int tls13_derive_finishedkey(SSL_CONNECTION *s, const EVP_MD *md,
148 const unsigned char *secret,
149 unsigned char *fin, size_t finlen)
150 {
151 /* ASCII: "finished", in hex for EBCDIC compatibility */
152 static const unsigned char finishedlabel[] = "\x66\x69\x6E\x69\x73\x68\x65\x64";
153
154 return tls13_hkdf_expand(s, md, secret, finishedlabel,
155 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
156 }
157
158 /*
159 * Given the previous secret |prevsecret| and a new input secret |insecret| of
160 * length |insecretlen|, generate a new secret and store it in the location
161 * pointed to by |outsecret|. Returns 1 on success 0 on failure.
162 */
tls13_generate_secret(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * prevsecret,const unsigned char * insecret,size_t insecretlen,unsigned char * outsecret)163 int tls13_generate_secret(SSL_CONNECTION *s, const EVP_MD *md,
164 const unsigned char *prevsecret,
165 const unsigned char *insecret,
166 size_t insecretlen,
167 unsigned char *outsecret)
168 {
169 size_t mdlen;
170 int mdleni;
171 int ret;
172 EVP_KDF *kdf;
173 EVP_KDF_CTX *kctx;
174 OSSL_PARAM params[7], *p = params;
175 int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
176 const char *mdname = EVP_MD_get0_name(md);
177 /* ASCII: "derived", in hex for EBCDIC compatibility */
178 static const char derived_secret_label[] = "\x64\x65\x72\x69\x76\x65\x64";
179 SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
180
181 kdf = EVP_KDF_fetch(sctx->libctx, OSSL_KDF_NAME_TLS1_3_KDF, sctx->propq);
182 kctx = EVP_KDF_CTX_new(kdf);
183 EVP_KDF_free(kdf);
184 if (kctx == NULL) {
185 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
186 return 0;
187 }
188
189 mdleni = EVP_MD_get_size(md);
190 /* Ensure cast to size_t is safe */
191 if (!ossl_assert(mdleni > 0)) {
192 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
193 EVP_KDF_CTX_free(kctx);
194 return 0;
195 }
196 mdlen = (size_t)mdleni;
197
198 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
199 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
200 (char *)mdname, 0);
201 if (insecret != NULL)
202 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
203 (unsigned char *)insecret,
204 insecretlen);
205 if (prevsecret != NULL)
206 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
207 (unsigned char *)prevsecret, mdlen);
208 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
209 (unsigned char *)label_prefix,
210 sizeof(label_prefix) - 1);
211 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
212 (unsigned char *)derived_secret_label,
213 sizeof(derived_secret_label) - 1);
214 *p++ = OSSL_PARAM_construct_end();
215
216 ret = EVP_KDF_derive(kctx, outsecret, mdlen, params) <= 0;
217
218 if (ret != 0)
219 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
220
221 EVP_KDF_CTX_free(kctx);
222 return ret == 0;
223 }
224
225 /*
226 * Given an input secret |insecret| of length |insecretlen| generate the
227 * handshake secret. This requires the early secret to already have been
228 * generated. Returns 1 on success 0 on failure.
229 */
tls13_generate_handshake_secret(SSL_CONNECTION * s,const unsigned char * insecret,size_t insecretlen)230 int tls13_generate_handshake_secret(SSL_CONNECTION *s,
231 const unsigned char *insecret,
232 size_t insecretlen)
233 {
234 /* Calls SSLfatal() if required */
235 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
236 insecret, insecretlen,
237 (unsigned char *)&s->handshake_secret);
238 }
239
240 /*
241 * Given the handshake secret |prev| of length |prevlen| generate the master
242 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
243 * failure.
244 */
tls13_generate_master_secret(SSL_CONNECTION * s,unsigned char * out,unsigned char * prev,size_t prevlen,size_t * secret_size)245 int tls13_generate_master_secret(SSL_CONNECTION *s, unsigned char *out,
246 unsigned char *prev, size_t prevlen,
247 size_t *secret_size)
248 {
249 const EVP_MD *md = ssl_handshake_md(s);
250 int md_size;
251
252 md_size = EVP_MD_get_size(md);
253 if (md_size <= 0) {
254 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
255 return 0;
256 }
257 *secret_size = (size_t)md_size;
258 /* Calls SSLfatal() if required */
259 return tls13_generate_secret(s, md, prev, NULL, 0, out);
260 }
261
262 /*
263 * Generates the mac for the Finished message. Returns the length of the MAC or
264 * 0 on error.
265 */
tls13_final_finish_mac(SSL_CONNECTION * s,const char * str,size_t slen,unsigned char * out)266 size_t tls13_final_finish_mac(SSL_CONNECTION *s, const char *str, size_t slen,
267 unsigned char *out)
268 {
269 const EVP_MD *md = ssl_handshake_md(s);
270 const char *mdname = EVP_MD_get0_name(md);
271 unsigned char hash[EVP_MAX_MD_SIZE];
272 unsigned char finsecret[EVP_MAX_MD_SIZE];
273 unsigned char *key = NULL;
274 size_t len = 0, hashlen;
275 OSSL_PARAM params[2], *p = params;
276 SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
277
278 if (md == NULL)
279 return 0;
280
281 /* Safe to cast away const here since we're not "getting" any data */
282 if (sctx->propq != NULL)
283 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
284 (char *)sctx->propq,
285 0);
286 *p = OSSL_PARAM_construct_end();
287
288 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
289 /* SSLfatal() already called */
290 goto err;
291 }
292
293 if (str == SSL_CONNECTION_GET_SSL(s)->method->ssl3_enc->server_finished_label) {
294 key = s->server_finished_secret;
295 } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
296 key = s->client_finished_secret;
297 } else {
298 if (!tls13_derive_finishedkey(s, md,
299 s->client_app_traffic_secret,
300 finsecret, hashlen))
301 goto err;
302 key = finsecret;
303 }
304
305 if (!EVP_Q_mac(sctx->libctx, "HMAC", sctx->propq, mdname,
306 params, key, hashlen, hash, hashlen,
307 /* outsize as per sizeof(peer_finish_md) */
308 out, EVP_MAX_MD_SIZE * 2, &len)) {
309 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
310 goto err;
311 }
312
313 err:
314 OPENSSL_cleanse(finsecret, sizeof(finsecret));
315 return len;
316 }
317
318 /*
319 * There isn't really a key block in TLSv1.3, but we still need this function
320 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
321 */
tls13_setup_key_block(SSL_CONNECTION * s)322 int tls13_setup_key_block(SSL_CONNECTION *s)
323 {
324 const EVP_CIPHER *c;
325 const EVP_MD *hash;
326 int mac_type = NID_undef;
327 size_t mac_secret_size = 0;
328
329 s->session->cipher = s->s3.tmp.new_cipher;
330 if (!ssl_cipher_get_evp(SSL_CONNECTION_GET_CTX(s), s->session, &c, &hash,
331 &mac_type, &mac_secret_size, NULL, 0)) {
332 /* Error is already recorded */
333 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
334 return 0;
335 }
336
337 ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
338 s->s3.tmp.new_sym_enc = c;
339 ssl_evp_md_free(s->s3.tmp.new_hash);
340 s->s3.tmp.new_hash = hash;
341 s->s3.tmp.new_mac_pkey_type = mac_type;
342 s->s3.tmp.new_mac_secret_size = mac_secret_size;
343
344 return 1;
345 }
346
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)347 static int derive_secret_key_and_iv(SSL_CONNECTION *s, const EVP_MD *md,
348 const EVP_CIPHER *ciph,
349 int mac_type,
350 const EVP_MD *mac_md,
351 const unsigned char *insecret,
352 const unsigned char *hash,
353 const unsigned char *label,
354 size_t labellen, unsigned char *secret,
355 unsigned char *key, size_t *keylen,
356 unsigned char **iv, size_t *ivlen,
357 size_t *taglen)
358 {
359 int hashleni = EVP_MD_get_size(md);
360 size_t hashlen;
361 int mode, mac_mdleni;
362
363 /* Ensure cast to size_t is safe */
364 if (!ossl_assert(hashleni > 0)) {
365 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
366 return 0;
367 }
368 hashlen = (size_t)hashleni;
369
370 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
371 secret, hashlen, 1)) {
372 /* SSLfatal() already called */
373 return 0;
374 }
375
376 /* if ciph is NULL cipher, then use new_hash to calculate keylen */
377 if (EVP_CIPHER_is_a(ciph, "NULL")
378 && mac_md != NULL
379 && mac_type == NID_hmac) {
380 mac_mdleni = EVP_MD_get_size(mac_md);
381
382 if (mac_mdleni <= 0) {
383 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
384 return 0;
385 }
386 *ivlen = *taglen = (size_t)mac_mdleni;
387 *keylen = s->s3.tmp.new_mac_secret_size;
388 } else {
389
390 *keylen = EVP_CIPHER_get_key_length(ciph);
391
392 mode = EVP_CIPHER_get_mode(ciph);
393 if (mode == EVP_CIPH_CCM_MODE) {
394 uint32_t algenc;
395
396 *ivlen = EVP_CCM_TLS_IV_LEN;
397 if (s->s3.tmp.new_cipher != NULL) {
398 algenc = s->s3.tmp.new_cipher->algorithm_enc;
399 } else if (s->session->cipher != NULL) {
400 /* We've not selected a cipher yet - we must be doing early data */
401 algenc = s->session->cipher->algorithm_enc;
402 } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
403 /* We must be doing early data with out-of-band PSK */
404 algenc = s->psksession->cipher->algorithm_enc;
405 } else {
406 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
407 return 0;
408 }
409 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
410 *taglen = EVP_CCM8_TLS_TAG_LEN;
411 else
412 *taglen = EVP_CCM_TLS_TAG_LEN;
413 } else {
414 int iivlen;
415
416 if (mode == EVP_CIPH_GCM_MODE) {
417 *taglen = EVP_GCM_TLS_TAG_LEN;
418 } else {
419 /* CHACHA20P-POLY1305 */
420 *taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
421 }
422 iivlen = EVP_CIPHER_get_iv_length(ciph);
423 if (iivlen < 0) {
424 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
425 return 0;
426 }
427 *ivlen = iivlen;
428 }
429 }
430
431 if (*ivlen > EVP_MAX_IV_LENGTH) {
432 *iv = OPENSSL_malloc(*ivlen);
433 if (*iv == NULL) {
434 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
435 return 0;
436 }
437 }
438
439 if (!tls13_derive_key(s, md, secret, key, *keylen)
440 || !tls13_derive_iv(s, md, secret, *iv, *ivlen)) {
441 /* SSLfatal() already called */
442 return 0;
443 }
444
445 return 1;
446 }
447
tls13_change_cipher_state(SSL_CONNECTION * s,int which)448 int tls13_change_cipher_state(SSL_CONNECTION *s, int which)
449 {
450 /* ASCII: "c e traffic", in hex for EBCDIC compatibility */
451 static const unsigned char client_early_traffic[] = "\x63\x20\x65\x20\x74\x72\x61\x66\x66\x69\x63";
452 /* ASCII: "c hs traffic", in hex for EBCDIC compatibility */
453 static const unsigned char client_handshake_traffic[] = "\x63\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
454 /* ASCII: "c ap traffic", in hex for EBCDIC compatibility */
455 static const unsigned char client_application_traffic[] = "\x63\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
456 /* ASCII: "s hs traffic", in hex for EBCDIC compatibility */
457 static const unsigned char server_handshake_traffic[] = "\x73\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
458 /* ASCII: "s ap traffic", in hex for EBCDIC compatibility */
459 static const unsigned char server_application_traffic[] = "\x73\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
460 /* ASCII: "exp master", in hex for EBCDIC compatibility */
461 static const unsigned char exporter_master_secret[] = "\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
462 /* ASCII: "res master", in hex for EBCDIC compatibility */
463 static const unsigned char resumption_master_secret[] = "\x72\x65\x73\x20\x6D\x61\x73\x74\x65\x72";
464 /* ASCII: "e exp master", in hex for EBCDIC compatibility */
465 static const unsigned char early_exporter_master_secret[] = "\x65\x20\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
466 unsigned char iv_intern[EVP_MAX_IV_LENGTH];
467 unsigned char *iv = iv_intern;
468 unsigned char key[EVP_MAX_KEY_LENGTH];
469 unsigned char secret[EVP_MAX_MD_SIZE];
470 unsigned char hashval[EVP_MAX_MD_SIZE];
471 unsigned char *hash = hashval;
472 unsigned char *insecret;
473 unsigned char *finsecret = NULL;
474 const char *log_label = NULL;
475 int finsecretlen = 0;
476 const unsigned char *label;
477 size_t labellen, hashlen = 0;
478 int ret = 0;
479 const EVP_MD *md = NULL, *mac_md = NULL;
480 const EVP_CIPHER *cipher = NULL;
481 int mac_pkey_type = NID_undef;
482 SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
483 size_t keylen, ivlen = EVP_MAX_IV_LENGTH, taglen;
484 int level;
485 int direction = (which & SSL3_CC_READ) != 0 ? OSSL_RECORD_DIRECTION_READ
486 : OSSL_RECORD_DIRECTION_WRITE;
487
488 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
489 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
490 if ((which & SSL3_CC_EARLY) != 0) {
491 EVP_MD_CTX *mdctx = NULL;
492 long handlen;
493 void *hdata;
494 unsigned int hashlenui;
495 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
496
497 insecret = s->early_secret;
498 label = client_early_traffic;
499 labellen = sizeof(client_early_traffic) - 1;
500 log_label = CLIENT_EARLY_LABEL;
501
502 handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
503 if (handlen <= 0) {
504 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
505 goto err;
506 }
507
508 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
509 && s->max_early_data > 0
510 && s->session->ext.max_early_data == 0) {
511 /*
512 * If we are attempting to send early data, and we've decided to
513 * actually do it but max_early_data in s->session is 0 then we
514 * must be using an external PSK.
515 */
516 if (!ossl_assert(s->psksession != NULL
517 && s->max_early_data ==
518 s->psksession->ext.max_early_data)) {
519 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
520 goto err;
521 }
522 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
523 }
524 if (sslcipher == NULL) {
525 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
526 goto err;
527 }
528
529 /*
530 * This ups the ref count on cipher so we better make sure we free
531 * it again
532 */
533 if (!ssl_cipher_get_evp_cipher(sctx, sslcipher, &cipher)) {
534 /* Error is already recorded */
535 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
536 goto err;
537 }
538
539 if (((EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) == 0)
540 && (!ssl_cipher_get_evp_md_mac(sctx, sslcipher, &mac_md,
541 &mac_pkey_type, NULL))) {
542 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
543 goto err;
544 }
545
546 /*
547 * We need to calculate the handshake digest using the digest from
548 * the session. We haven't yet selected our ciphersuite so we can't
549 * use ssl_handshake_md().
550 */
551 mdctx = EVP_MD_CTX_new();
552 if (mdctx == NULL) {
553 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
554 goto err;
555 }
556
557 md = ssl_md(sctx, sslcipher->algorithm2);
558 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
559 || !EVP_DigestUpdate(mdctx, hdata, handlen)
560 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
561 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
562 EVP_MD_CTX_free(mdctx);
563 goto err;
564 }
565 hashlen = hashlenui;
566 EVP_MD_CTX_free(mdctx);
567
568 if (!tls13_hkdf_expand(s, md, insecret,
569 early_exporter_master_secret,
570 sizeof(early_exporter_master_secret) - 1,
571 hashval, hashlen,
572 s->early_exporter_master_secret, hashlen,
573 1)) {
574 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
575 goto err;
576 }
577
578 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
579 s->early_exporter_master_secret, hashlen)) {
580 /* SSLfatal() already called */
581 goto err;
582 }
583 } else if (which & SSL3_CC_HANDSHAKE) {
584 insecret = s->handshake_secret;
585 finsecret = s->client_finished_secret;
586 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
587 if (finsecretlen <= 0) {
588 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
589 goto err;
590 }
591 label = client_handshake_traffic;
592 labellen = sizeof(client_handshake_traffic) - 1;
593 log_label = CLIENT_HANDSHAKE_LABEL;
594 /*
595 * The handshake hash used for the server read/client write handshake
596 * traffic secret is the same as the hash for the server
597 * write/client read handshake traffic secret. However, if we
598 * processed early data then we delay changing the server
599 * read/client write cipher state until later, and the handshake
600 * hashes have moved on. Therefore we use the value saved earlier
601 * when we did the server write/client read change cipher state.
602 */
603 hash = s->handshake_traffic_hash;
604 } else {
605 insecret = s->master_secret;
606 label = client_application_traffic;
607 labellen = sizeof(client_application_traffic) - 1;
608 log_label = CLIENT_APPLICATION_LABEL;
609 /*
610 * For this we only use the handshake hashes up until the server
611 * Finished hash. We do not include the client's Finished, which is
612 * what ssl_handshake_hash() would give us. Instead we use the
613 * previously saved value.
614 */
615 hash = s->server_finished_hash;
616 }
617 } else {
618 /* Early data never applies to client-read/server-write */
619 if (which & SSL3_CC_HANDSHAKE) {
620 insecret = s->handshake_secret;
621 finsecret = s->server_finished_secret;
622 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
623 if (finsecretlen <= 0) {
624 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
625 goto err;
626 }
627 label = server_handshake_traffic;
628 labellen = sizeof(server_handshake_traffic) - 1;
629 log_label = SERVER_HANDSHAKE_LABEL;
630 } else {
631 insecret = s->master_secret;
632 label = server_application_traffic;
633 labellen = sizeof(server_application_traffic) - 1;
634 log_label = SERVER_APPLICATION_LABEL;
635 }
636 }
637
638 if ((which & SSL3_CC_EARLY) == 0) {
639 md = ssl_handshake_md(s);
640 cipher = s->s3.tmp.new_sym_enc;
641 mac_md = s->s3.tmp.new_hash;
642 mac_pkey_type = s->s3.tmp.new_mac_pkey_type;
643 if (!ssl3_digest_cached_records(s, 1)
644 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
645 /* SSLfatal() already called */;
646 goto err;
647 }
648 }
649
650 /*
651 * Save the hash of handshakes up to now for use when we calculate the
652 * client application traffic secret
653 */
654 if (label == server_application_traffic)
655 memcpy(s->server_finished_hash, hashval, hashlen);
656
657 if (label == server_handshake_traffic)
658 memcpy(s->handshake_traffic_hash, hashval, hashlen);
659
660 if (label == client_application_traffic) {
661 /*
662 * We also create the resumption master secret, but this time use the
663 * hash for the whole handshake including the Client Finished
664 */
665 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
666 resumption_master_secret,
667 sizeof(resumption_master_secret) - 1,
668 hashval, hashlen, s->resumption_master_secret,
669 hashlen, 1)) {
670 /* SSLfatal() already called */
671 goto err;
672 }
673 }
674
675 /* check whether cipher is known */
676 if (!ossl_assert(cipher != NULL))
677 goto err;
678
679 if (!derive_secret_key_and_iv(s, md, cipher, mac_pkey_type, mac_md,
680 insecret, hash, label, labellen, secret, key,
681 &keylen, &iv, &ivlen, &taglen)) {
682 /* SSLfatal() already called */
683 goto err;
684 }
685
686 if (label == server_application_traffic) {
687 memcpy(s->server_app_traffic_secret, secret, hashlen);
688 /* Now we create the exporter master secret */
689 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
690 exporter_master_secret,
691 sizeof(exporter_master_secret) - 1,
692 hash, hashlen, s->exporter_master_secret,
693 hashlen, 1)) {
694 /* SSLfatal() already called */
695 goto err;
696 }
697
698 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
699 hashlen)) {
700 /* SSLfatal() already called */
701 goto err;
702 }
703 } else if (label == client_application_traffic)
704 memcpy(s->client_app_traffic_secret, secret, hashlen);
705
706 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
707 /* SSLfatal() already called */
708 goto err;
709 }
710
711 if (finsecret != NULL
712 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
713 finsecret, (size_t)finsecretlen)) {
714 /* SSLfatal() already called */
715 goto err;
716 }
717
718 if ((which & SSL3_CC_WRITE) != 0) {
719 if (!s->server && label == client_early_traffic)
720 s->rlayer.wrlmethod->set_plain_alerts(s->rlayer.wrl, 1);
721 else
722 s->rlayer.wrlmethod->set_plain_alerts(s->rlayer.wrl, 0);
723 }
724
725 level = (which & SSL3_CC_EARLY) != 0
726 ? OSSL_RECORD_PROTECTION_LEVEL_EARLY
727 : ((which &SSL3_CC_HANDSHAKE) != 0
728 ? OSSL_RECORD_PROTECTION_LEVEL_HANDSHAKE
729 : OSSL_RECORD_PROTECTION_LEVEL_APPLICATION);
730
731 if (!ssl_set_new_record_layer(s, s->version,
732 direction,
733 level, secret, hashlen, key, keylen, iv,
734 ivlen, NULL, 0, cipher, taglen,
735 mac_pkey_type, mac_md, NULL, md)) {
736 /* SSLfatal already called */
737 goto err;
738 }
739
740 ret = 1;
741 err:
742 if ((which & SSL3_CC_EARLY) != 0) {
743 /* We up-refed this so now we need to down ref */
744 if ((EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) == 0)
745 ssl_evp_md_free(mac_md);
746 ssl_evp_cipher_free(cipher);
747 }
748 OPENSSL_cleanse(key, sizeof(key));
749 OPENSSL_cleanse(secret, sizeof(secret));
750 if (iv != iv_intern)
751 OPENSSL_free(iv);
752 return ret;
753 }
754
tls13_update_key(SSL_CONNECTION * s,int sending)755 int tls13_update_key(SSL_CONNECTION *s, int sending)
756 {
757 /* ASCII: "traffic upd", in hex for EBCDIC compatibility */
758 static const unsigned char application_traffic[] = "\x74\x72\x61\x66\x66\x69\x63\x20\x75\x70\x64";
759 const EVP_MD *md = ssl_handshake_md(s);
760 size_t hashlen;
761 unsigned char key[EVP_MAX_KEY_LENGTH];
762 unsigned char *insecret;
763 unsigned char secret[EVP_MAX_MD_SIZE];
764 char *log_label;
765 size_t keylen, ivlen, taglen;
766 int ret = 0, l;
767 int direction = sending ? OSSL_RECORD_DIRECTION_WRITE
768 : OSSL_RECORD_DIRECTION_READ;
769 unsigned char iv_intern[EVP_MAX_IV_LENGTH];
770 unsigned char *iv = iv_intern;
771
772 if ((l = EVP_MD_get_size(md)) <= 0) {
773 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
774 return 0;
775 }
776 hashlen = (size_t)l;
777
778 if (s->server == sending)
779 insecret = s->server_app_traffic_secret;
780 else
781 insecret = s->client_app_traffic_secret;
782
783 if (!derive_secret_key_and_iv(s, md,
784 s->s3.tmp.new_sym_enc,
785 s->s3.tmp.new_mac_pkey_type, s->s3.tmp.new_hash,
786 insecret, NULL,
787 application_traffic,
788 sizeof(application_traffic) - 1, secret, key,
789 &keylen, &iv, &ivlen, &taglen)) {
790 /* SSLfatal() already called */
791 goto err;
792 }
793
794 memcpy(insecret, secret, hashlen);
795
796 if (!ssl_set_new_record_layer(s, s->version,
797 direction,
798 OSSL_RECORD_PROTECTION_LEVEL_APPLICATION,
799 insecret, hashlen, key, keylen, iv, ivlen, NULL, 0,
800 s->s3.tmp.new_sym_enc, taglen, NID_undef, NULL,
801 NULL, md)) {
802 /* SSLfatal already called */
803 goto err;
804 }
805
806 /* Call Key log on successful traffic secret update */
807 log_label = s->server == sending ? SERVER_APPLICATION_N_LABEL : CLIENT_APPLICATION_N_LABEL;
808 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
809 /* SSLfatal() already called */
810 goto err;
811 }
812 ret = 1;
813 err:
814 OPENSSL_cleanse(key, sizeof(key));
815 OPENSSL_cleanse(secret, sizeof(secret));
816 if (iv != iv_intern)
817 OPENSSL_free(iv);
818 return ret;
819 }
820
tls13_alert_code(int code)821 int tls13_alert_code(int code)
822 {
823 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
824 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
825 return code;
826
827 return tls1_alert_code(code);
828 }
829
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)830 int tls13_export_keying_material(SSL_CONNECTION *s,
831 unsigned char *out, size_t olen,
832 const char *label, size_t llen,
833 const unsigned char *context,
834 size_t contextlen, int use_context)
835 {
836 unsigned char exportsecret[EVP_MAX_MD_SIZE];
837 /* ASCII: "exporter", in hex for EBCDIC compatibility */
838 static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
839 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
840 const EVP_MD *md = ssl_handshake_md(s);
841 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
842 unsigned int hashsize, datalen;
843 int ret = 0;
844
845 if (ctx == NULL || md == NULL || !ossl_statem_export_allowed(s))
846 goto err;
847
848 if (!use_context)
849 contextlen = 0;
850
851 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
852 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
853 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
854 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
855 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
856 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
857 (const unsigned char *)label, llen,
858 data, datalen, exportsecret, hashsize, 0)
859 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
860 sizeof(exporterlabel) - 1, hash, hashsize,
861 out, olen, 0))
862 goto err;
863
864 ret = 1;
865 err:
866 EVP_MD_CTX_free(ctx);
867 return ret;
868 }
869
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)870 int tls13_export_keying_material_early(SSL_CONNECTION *s,
871 unsigned char *out, size_t olen,
872 const char *label, size_t llen,
873 const unsigned char *context,
874 size_t contextlen)
875 {
876 /* ASCII: "exporter", in hex for EBCDIC compatibility */
877 static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
878 unsigned char exportsecret[EVP_MAX_MD_SIZE];
879 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
880 const EVP_MD *md;
881 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
882 unsigned int hashsize, datalen;
883 int ret = 0;
884 const SSL_CIPHER *sslcipher;
885
886 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
887 goto err;
888
889 if (!s->server && s->max_early_data > 0
890 && s->session->ext.max_early_data == 0)
891 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
892 else
893 sslcipher = SSL_SESSION_get0_cipher(s->session);
894
895 md = ssl_md(SSL_CONNECTION_GET_CTX(s), sslcipher->algorithm2);
896
897 /*
898 * Calculate the hash value and store it in |data|. The reason why
899 * the empty string is used is that the definition of TLS-Exporter
900 * is like so:
901 *
902 * TLS-Exporter(label, context_value, key_length) =
903 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
904 * "exporter", Hash(context_value), key_length)
905 *
906 * Derive-Secret(Secret, Label, Messages) =
907 * HKDF-Expand-Label(Secret, Label,
908 * Transcript-Hash(Messages), Hash.length)
909 *
910 * Here Transcript-Hash is the cipher suite hash algorithm.
911 */
912 if (md == NULL
913 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
914 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
915 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
916 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
917 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
918 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
919 (const unsigned char *)label, llen,
920 data, datalen, exportsecret, hashsize, 0)
921 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
922 sizeof(exporterlabel) - 1, hash, hashsize,
923 out, olen, 0))
924 goto err;
925
926 ret = 1;
927 err:
928 EVP_MD_CTX_free(ctx);
929 return ret;
930 }
931
