1 /*
2 * Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (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/cryptlib.h"
13 #include <openssl/evp.h>
14 #include <openssl/kdf.h>
15
16 #define TLS13_MAX_LABEL_LEN 249
17
18 /* Always filled with zeros */
19 static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
20
21 /*
22 * Given a |secret|; a |label| of length |labellen|; and |data| of length
23 * |datalen| (e.g. typically a hash of the handshake messages), derive a new
24 * secret |outlen| bytes long and store it in the location pointed to be |out|.
25 * The |data| value may be zero length. Any errors will be treated as fatal if
26 * |fatal| is set. Returns 1 on success 0 on failure.
27 */
tls13_hkdf_expand(SSL * 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)28 int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
29 const unsigned char *label, size_t labellen,
30 const unsigned char *data, size_t datalen,
31 unsigned char *out, size_t outlen, int fatal)
32 {
33 #ifdef CHARSET_EBCDIC
34 static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 };
35 #else
36 static const unsigned char label_prefix[] = "tls13 ";
37 #endif
38 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
39 int ret;
40 size_t hkdflabellen;
41 size_t hashlen;
42 /*
43 * 2 bytes for length of derived secret + 1 byte for length of combined
44 * prefix and label + bytes for the label itself + 1 byte length of hash
45 * + bytes for the hash itself
46 */
47 unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t)
48 + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN
49 + 1 + EVP_MAX_MD_SIZE];
50 WPACKET pkt;
51
52 if (pctx == NULL)
53 return 0;
54
55 if (labellen > TLS13_MAX_LABEL_LEN) {
56 if (fatal) {
57 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
58 ERR_R_INTERNAL_ERROR);
59 } else {
60 /*
61 * Probably we have been called from SSL_export_keying_material(),
62 * or SSL_export_keying_material_early().
63 */
64 SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
65 }
66 EVP_PKEY_CTX_free(pctx);
67 return 0;
68 }
69
70 hashlen = EVP_MD_size(md);
71
72 if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
73 || !WPACKET_put_bytes_u16(&pkt, outlen)
74 || !WPACKET_start_sub_packet_u8(&pkt)
75 || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
76 || !WPACKET_memcpy(&pkt, label, labellen)
77 || !WPACKET_close(&pkt)
78 || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
79 || !WPACKET_get_total_written(&pkt, &hkdflabellen)
80 || !WPACKET_finish(&pkt)) {
81 EVP_PKEY_CTX_free(pctx);
82 WPACKET_cleanup(&pkt);
83 if (fatal)
84 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
85 ERR_R_INTERNAL_ERROR);
86 else
87 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
88 return 0;
89 }
90
91 ret = EVP_PKEY_derive_init(pctx) <= 0
92 || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY)
93 <= 0
94 || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
95 || EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, hashlen) <= 0
96 || EVP_PKEY_CTX_add1_hkdf_info(pctx, hkdflabel, hkdflabellen) <= 0
97 || EVP_PKEY_derive(pctx, out, &outlen) <= 0;
98
99 EVP_PKEY_CTX_free(pctx);
100
101 if (ret != 0) {
102 if (fatal)
103 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
104 ERR_R_INTERNAL_ERROR);
105 else
106 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
107 }
108
109 return ret == 0;
110 }
111
112 /*
113 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
114 * success 0 on failure.
115 */
tls13_derive_key(SSL * s,const EVP_MD * md,const unsigned char * secret,unsigned char * key,size_t keylen)116 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
117 unsigned char *key, size_t keylen)
118 {
119 #ifdef CHARSET_EBCDIC
120 static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 };
121 #else
122 static const unsigned char keylabel[] = "key";
123 #endif
124
125 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
126 NULL, 0, key, keylen, 1);
127 }
128
129 /*
130 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
131 * success 0 on failure.
132 */
tls13_derive_iv(SSL * s,const EVP_MD * md,const unsigned char * secret,unsigned char * iv,size_t ivlen)133 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
134 unsigned char *iv, size_t ivlen)
135 {
136 #ifdef CHARSET_EBCDIC
137 static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 };
138 #else
139 static const unsigned char ivlabel[] = "iv";
140 #endif
141
142 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
143 NULL, 0, iv, ivlen, 1);
144 }
145
tls13_derive_finishedkey(SSL * s,const EVP_MD * md,const unsigned char * secret,unsigned char * fin,size_t finlen)146 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
147 const unsigned char *secret,
148 unsigned char *fin, size_t finlen)
149 {
150 #ifdef CHARSET_EBCDIC
151 static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 };
152 #else
153 static const unsigned char finishedlabel[] = "finished";
154 #endif
155
156 return tls13_hkdf_expand(s, md, secret, finishedlabel,
157 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
158 }
159
160 /*
161 * Given the previous secret |prevsecret| and a new input secret |insecret| of
162 * length |insecretlen|, generate a new secret and store it in the location
163 * pointed to by |outsecret|. Returns 1 on success 0 on failure.
164 */
tls13_generate_secret(SSL * s,const EVP_MD * md,const unsigned char * prevsecret,const unsigned char * insecret,size_t insecretlen,unsigned char * outsecret)165 int tls13_generate_secret(SSL *s, const EVP_MD *md,
166 const unsigned char *prevsecret,
167 const unsigned char *insecret,
168 size_t insecretlen,
169 unsigned char *outsecret)
170 {
171 size_t mdlen, prevsecretlen;
172 int mdleni;
173 int ret;
174 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
175 #ifdef CHARSET_EBCDIC
176 static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 };
177 #else
178 static const char derived_secret_label[] = "derived";
179 #endif
180 unsigned char preextractsec[EVP_MAX_MD_SIZE];
181
182 if (pctx == NULL) {
183 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
184 ERR_R_INTERNAL_ERROR);
185 return 0;
186 }
187
188 mdleni = EVP_MD_size(md);
189 /* Ensure cast to size_t is safe */
190 if (!ossl_assert(mdleni >= 0)) {
191 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
192 ERR_R_INTERNAL_ERROR);
193 EVP_PKEY_CTX_free(pctx);
194 return 0;
195 }
196 mdlen = (size_t)mdleni;
197
198 if (insecret == NULL) {
199 insecret = default_zeros;
200 insecretlen = mdlen;
201 }
202 if (prevsecret == NULL) {
203 prevsecret = default_zeros;
204 prevsecretlen = 0;
205 } else {
206 EVP_MD_CTX *mctx = EVP_MD_CTX_new();
207 unsigned char hash[EVP_MAX_MD_SIZE];
208
209 /* The pre-extract derive step uses a hash of no messages */
210 if (mctx == NULL
211 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
212 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
213 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
214 ERR_R_INTERNAL_ERROR);
215 EVP_MD_CTX_free(mctx);
216 EVP_PKEY_CTX_free(pctx);
217 return 0;
218 }
219 EVP_MD_CTX_free(mctx);
220
221 /* Generate the pre-extract secret */
222 if (!tls13_hkdf_expand(s, md, prevsecret,
223 (unsigned char *)derived_secret_label,
224 sizeof(derived_secret_label) - 1, hash, mdlen,
225 preextractsec, mdlen, 1)) {
226 /* SSLfatal() already called */
227 EVP_PKEY_CTX_free(pctx);
228 return 0;
229 }
230
231 prevsecret = preextractsec;
232 prevsecretlen = mdlen;
233 }
234
235 ret = EVP_PKEY_derive_init(pctx) <= 0
236 || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY)
237 <= 0
238 || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
239 || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0
240 || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen)
241 <= 0
242 || EVP_PKEY_derive(pctx, outsecret, &mdlen)
243 <= 0;
244
245 if (ret != 0)
246 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
247 ERR_R_INTERNAL_ERROR);
248
249 EVP_PKEY_CTX_free(pctx);
250 if (prevsecret == preextractsec)
251 OPENSSL_cleanse(preextractsec, mdlen);
252 return ret == 0;
253 }
254
255 /*
256 * Given an input secret |insecret| of length |insecretlen| generate the
257 * handshake secret. This requires the early secret to already have been
258 * generated. Returns 1 on success 0 on failure.
259 */
tls13_generate_handshake_secret(SSL * s,const unsigned char * insecret,size_t insecretlen)260 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
261 size_t insecretlen)
262 {
263 /* Calls SSLfatal() if required */
264 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
265 insecret, insecretlen,
266 (unsigned char *)&s->handshake_secret);
267 }
268
269 /*
270 * Given the handshake secret |prev| of length |prevlen| generate the master
271 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
272 * failure.
273 */
tls13_generate_master_secret(SSL * s,unsigned char * out,unsigned char * prev,size_t prevlen,size_t * secret_size)274 int tls13_generate_master_secret(SSL *s, unsigned char *out,
275 unsigned char *prev, size_t prevlen,
276 size_t *secret_size)
277 {
278 const EVP_MD *md = ssl_handshake_md(s);
279
280 *secret_size = EVP_MD_size(md);
281 /* Calls SSLfatal() if required */
282 return tls13_generate_secret(s, md, prev, NULL, 0, out);
283 }
284
285 /*
286 * Generates the mac for the Finished message. Returns the length of the MAC or
287 * 0 on error.
288 */
tls13_final_finish_mac(SSL * s,const char * str,size_t slen,unsigned char * out)289 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
290 unsigned char *out)
291 {
292 const EVP_MD *md = ssl_handshake_md(s);
293 unsigned char hash[EVP_MAX_MD_SIZE];
294 size_t hashlen, ret = 0;
295 EVP_PKEY *key = NULL;
296 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
297
298 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
299 /* SSLfatal() already called */
300 goto err;
301 }
302
303 if (str == s->method->ssl3_enc->server_finished_label) {
304 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
305 s->server_finished_secret, hashlen);
306 } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
307 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
308 s->client_finished_secret, hashlen);
309 } else {
310 unsigned char finsecret[EVP_MAX_MD_SIZE];
311
312 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
313 s->client_app_traffic_secret,
314 finsecret, hashlen))
315 goto err;
316
317 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret,
318 hashlen);
319 OPENSSL_cleanse(finsecret, sizeof(finsecret));
320 }
321
322 if (key == NULL
323 || ctx == NULL
324 || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0
325 || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0
326 || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) {
327 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
328 ERR_R_INTERNAL_ERROR);
329 goto err;
330 }
331
332 ret = hashlen;
333 err:
334 EVP_PKEY_free(key);
335 EVP_MD_CTX_free(ctx);
336 return ret;
337 }
338
339 /*
340 * There isn't really a key block in TLSv1.3, but we still need this function
341 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
342 */
tls13_setup_key_block(SSL * s)343 int tls13_setup_key_block(SSL *s)
344 {
345 const EVP_CIPHER *c;
346 const EVP_MD *hash;
347
348 s->session->cipher = s->s3->tmp.new_cipher;
349 if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) {
350 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK,
351 SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
352 return 0;
353 }
354
355 s->s3->tmp.new_sym_enc = c;
356 s->s3->tmp.new_hash = hash;
357
358 return 1;
359 }
360
derive_secret_key_and_iv(SSL * s,int sending,const EVP_MD * md,const EVP_CIPHER * ciph,const unsigned char * insecret,const unsigned char * hash,const unsigned char * label,size_t labellen,unsigned char * secret,unsigned char * iv,EVP_CIPHER_CTX * ciph_ctx)361 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
362 const EVP_CIPHER *ciph,
363 const unsigned char *insecret,
364 const unsigned char *hash,
365 const unsigned char *label,
366 size_t labellen, unsigned char *secret,
367 unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx)
368 {
369 unsigned char key[EVP_MAX_KEY_LENGTH];
370 size_t ivlen, keylen, taglen;
371 int hashleni = EVP_MD_size(md);
372 size_t hashlen;
373
374 /* Ensure cast to size_t is safe */
375 if (!ossl_assert(hashleni >= 0)) {
376 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
377 ERR_R_EVP_LIB);
378 goto err;
379 }
380 hashlen = (size_t)hashleni;
381
382 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
383 secret, hashlen, 1)) {
384 /* SSLfatal() already called */
385 goto err;
386 }
387
388 /* TODO(size_t): convert me */
389 keylen = EVP_CIPHER_key_length(ciph);
390 if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
391 uint32_t algenc;
392
393 ivlen = EVP_CCM_TLS_IV_LEN;
394 if (s->s3->tmp.new_cipher != NULL) {
395 algenc = s->s3->tmp.new_cipher->algorithm_enc;
396 } else if (s->session->cipher != NULL) {
397 /* We've not selected a cipher yet - we must be doing early data */
398 algenc = s->session->cipher->algorithm_enc;
399 } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
400 /* We must be doing early data with out-of-band PSK */
401 algenc = s->psksession->cipher->algorithm_enc;
402 } else {
403 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
404 ERR_R_EVP_LIB);
405 goto err;
406 }
407 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
408 taglen = EVP_CCM8_TLS_TAG_LEN;
409 else
410 taglen = EVP_CCM_TLS_TAG_LEN;
411 } else {
412 ivlen = EVP_CIPHER_iv_length(ciph);
413 taglen = 0;
414 }
415
416 if (!tls13_derive_key(s, md, secret, key, keylen)
417 || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
418 /* SSLfatal() already called */
419 goto err;
420 }
421
422 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
423 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
424 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
425 taglen, NULL))
426 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
427 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
428 ERR_R_EVP_LIB);
429 goto err;
430 }
431
432 return 1;
433 err:
434 OPENSSL_cleanse(key, sizeof(key));
435 return 0;
436 }
437
tls13_change_cipher_state(SSL * s,int which)438 int tls13_change_cipher_state(SSL *s, int which)
439 {
440 #ifdef CHARSET_EBCDIC
441 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
442 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
443 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
444 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
445 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
446 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
447 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
448 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
449 #else
450 static const unsigned char client_early_traffic[] = "c e traffic";
451 static const unsigned char client_handshake_traffic[] = "c hs traffic";
452 static const unsigned char client_application_traffic[] = "c ap traffic";
453 static const unsigned char server_handshake_traffic[] = "s hs traffic";
454 static const unsigned char server_application_traffic[] = "s ap traffic";
455 static const unsigned char exporter_master_secret[] = "exp master";
456 static const unsigned char resumption_master_secret[] = "res master";
457 static const unsigned char early_exporter_master_secret[] = "e exp master";
458 #endif
459 unsigned char *iv;
460 unsigned char secret[EVP_MAX_MD_SIZE];
461 unsigned char hashval[EVP_MAX_MD_SIZE];
462 unsigned char *hash = hashval;
463 unsigned char *insecret;
464 unsigned char *finsecret = NULL;
465 const char *log_label = NULL;
466 EVP_CIPHER_CTX *ciph_ctx;
467 size_t finsecretlen = 0;
468 const unsigned char *label;
469 size_t labellen, hashlen = 0;
470 int ret = 0;
471 const EVP_MD *md = NULL;
472 const EVP_CIPHER *cipher = NULL;
473
474 if (which & SSL3_CC_READ) {
475 if (s->enc_read_ctx != NULL) {
476 EVP_CIPHER_CTX_reset(s->enc_read_ctx);
477 } else {
478 s->enc_read_ctx = EVP_CIPHER_CTX_new();
479 if (s->enc_read_ctx == NULL) {
480 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
481 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
482 goto err;
483 }
484 }
485 ciph_ctx = s->enc_read_ctx;
486 iv = s->read_iv;
487
488 RECORD_LAYER_reset_read_sequence(&s->rlayer);
489 } else {
490 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
491 if (s->enc_write_ctx != NULL) {
492 EVP_CIPHER_CTX_reset(s->enc_write_ctx);
493 } else {
494 s->enc_write_ctx = EVP_CIPHER_CTX_new();
495 if (s->enc_write_ctx == NULL) {
496 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
497 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
498 goto err;
499 }
500 }
501 ciph_ctx = s->enc_write_ctx;
502 iv = s->write_iv;
503
504 RECORD_LAYER_reset_write_sequence(&s->rlayer);
505 }
506
507 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
508 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
509 if (which & SSL3_CC_EARLY) {
510 EVP_MD_CTX *mdctx = NULL;
511 long handlen;
512 void *hdata;
513 unsigned int hashlenui;
514 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
515
516 insecret = s->early_secret;
517 label = client_early_traffic;
518 labellen = sizeof(client_early_traffic) - 1;
519 log_label = CLIENT_EARLY_LABEL;
520
521 handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
522 if (handlen <= 0) {
523 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
524 SSL_F_TLS13_CHANGE_CIPHER_STATE,
525 SSL_R_BAD_HANDSHAKE_LENGTH);
526 goto err;
527 }
528
529 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
530 && s->max_early_data > 0
531 && s->session->ext.max_early_data == 0) {
532 /*
533 * If we are attempting to send early data, and we've decided to
534 * actually do it but max_early_data in s->session is 0 then we
535 * must be using an external PSK.
536 */
537 if (!ossl_assert(s->psksession != NULL
538 && s->max_early_data ==
539 s->psksession->ext.max_early_data)) {
540 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
541 SSL_F_TLS13_CHANGE_CIPHER_STATE,
542 ERR_R_INTERNAL_ERROR);
543 goto err;
544 }
545 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
546 }
547 if (sslcipher == NULL) {
548 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
549 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK);
550 goto err;
551 }
552
553 /*
554 * We need to calculate the handshake digest using the digest from
555 * the session. We haven't yet selected our ciphersuite so we can't
556 * use ssl_handshake_md().
557 */
558 mdctx = EVP_MD_CTX_new();
559 if (mdctx == NULL) {
560 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
561 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
562 goto err;
563 }
564 cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher));
565 md = ssl_md(sslcipher->algorithm2);
566 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
567 || !EVP_DigestUpdate(mdctx, hdata, handlen)
568 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
569 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
570 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
571 EVP_MD_CTX_free(mdctx);
572 goto err;
573 }
574 hashlen = hashlenui;
575 EVP_MD_CTX_free(mdctx);
576
577 if (!tls13_hkdf_expand(s, md, insecret,
578 early_exporter_master_secret,
579 sizeof(early_exporter_master_secret) - 1,
580 hashval, hashlen,
581 s->early_exporter_master_secret, hashlen,
582 1)) {
583 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
584 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
585 goto err;
586 }
587
588 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
589 s->early_exporter_master_secret, hashlen)) {
590 /* SSLfatal() already called */
591 goto err;
592 }
593 } else if (which & SSL3_CC_HANDSHAKE) {
594 insecret = s->handshake_secret;
595 finsecret = s->client_finished_secret;
596 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
597 label = client_handshake_traffic;
598 labellen = sizeof(client_handshake_traffic) - 1;
599 log_label = CLIENT_HANDSHAKE_LABEL;
600 /*
601 * The handshake hash used for the server read/client write handshake
602 * traffic secret is the same as the hash for the server
603 * write/client read handshake traffic secret. However, if we
604 * processed early data then we delay changing the server
605 * read/client write cipher state until later, and the handshake
606 * hashes have moved on. Therefore we use the value saved earlier
607 * when we did the server write/client read change cipher state.
608 */
609 hash = s->handshake_traffic_hash;
610 } else {
611 insecret = s->master_secret;
612 label = client_application_traffic;
613 labellen = sizeof(client_application_traffic) - 1;
614 log_label = CLIENT_APPLICATION_LABEL;
615 /*
616 * For this we only use the handshake hashes up until the server
617 * Finished hash. We do not include the client's Finished, which is
618 * what ssl_handshake_hash() would give us. Instead we use the
619 * previously saved value.
620 */
621 hash = s->server_finished_hash;
622 }
623 } else {
624 /* Early data never applies to client-read/server-write */
625 if (which & SSL3_CC_HANDSHAKE) {
626 insecret = s->handshake_secret;
627 finsecret = s->server_finished_secret;
628 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
629 label = server_handshake_traffic;
630 labellen = sizeof(server_handshake_traffic) - 1;
631 log_label = SERVER_HANDSHAKE_LABEL;
632 } else {
633 insecret = s->master_secret;
634 label = server_application_traffic;
635 labellen = sizeof(server_application_traffic) - 1;
636 log_label = SERVER_APPLICATION_LABEL;
637 }
638 }
639
640 if (!(which & SSL3_CC_EARLY)) {
641 md = ssl_handshake_md(s);
642 cipher = s->s3->tmp.new_sym_enc;
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 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
676 insecret, hash, label, labellen, secret, iv,
677 ciph_ctx)) {
678 /* SSLfatal() already called */
679 goto err;
680 }
681
682 if (label == server_application_traffic) {
683 memcpy(s->server_app_traffic_secret, secret, hashlen);
684 /* Now we create the exporter master secret */
685 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
686 exporter_master_secret,
687 sizeof(exporter_master_secret) - 1,
688 hash, hashlen, s->exporter_master_secret,
689 hashlen, 1)) {
690 /* SSLfatal() already called */
691 goto err;
692 }
693
694 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
695 hashlen)) {
696 /* SSLfatal() already called */
697 goto err;
698 }
699 } else if (label == client_application_traffic)
700 memcpy(s->client_app_traffic_secret, secret, hashlen);
701
702 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
703 /* SSLfatal() already called */
704 goto err;
705 }
706
707 if (finsecret != NULL
708 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
709 finsecret, finsecretlen)) {
710 /* SSLfatal() already called */
711 goto err;
712 }
713
714 if (!s->server && label == client_early_traffic)
715 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
716 else
717 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
718 ret = 1;
719 err:
720 OPENSSL_cleanse(secret, sizeof(secret));
721 return ret;
722 }
723
tls13_update_key(SSL * s,int sending)724 int tls13_update_key(SSL *s, int sending)
725 {
726 #ifdef CHARSET_EBCDIC
727 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
728 #else
729 static const unsigned char application_traffic[] = "traffic upd";
730 #endif
731 const EVP_MD *md = ssl_handshake_md(s);
732 size_t hashlen = EVP_MD_size(md);
733 unsigned char *insecret, *iv;
734 unsigned char secret[EVP_MAX_MD_SIZE];
735 EVP_CIPHER_CTX *ciph_ctx;
736 int ret = 0;
737
738 if (s->server == sending)
739 insecret = s->server_app_traffic_secret;
740 else
741 insecret = s->client_app_traffic_secret;
742
743 if (sending) {
744 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
745 iv = s->write_iv;
746 ciph_ctx = s->enc_write_ctx;
747 RECORD_LAYER_reset_write_sequence(&s->rlayer);
748 } else {
749 iv = s->read_iv;
750 ciph_ctx = s->enc_read_ctx;
751 RECORD_LAYER_reset_read_sequence(&s->rlayer);
752 }
753
754 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
755 s->s3->tmp.new_sym_enc, insecret, NULL,
756 application_traffic,
757 sizeof(application_traffic) - 1, secret, iv,
758 ciph_ctx)) {
759 /* SSLfatal() already called */
760 goto err;
761 }
762
763 memcpy(insecret, secret, hashlen);
764
765 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
766 ret = 1;
767 err:
768 OPENSSL_cleanse(secret, sizeof(secret));
769 return ret;
770 }
771
tls13_alert_code(int code)772 int tls13_alert_code(int code)
773 {
774 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
775 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
776 return code;
777
778 return tls1_alert_code(code);
779 }
780
tls13_export_keying_material(SSL * s,unsigned char * out,size_t olen,const char * label,size_t llen,const unsigned char * context,size_t contextlen,int use_context)781 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
782 const char *label, size_t llen,
783 const unsigned char *context,
784 size_t contextlen, int use_context)
785 {
786 unsigned char exportsecret[EVP_MAX_MD_SIZE];
787 #ifdef CHARSET_EBCDIC
788 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
789 #else
790 static const unsigned char exporterlabel[] = "exporter";
791 #endif
792 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
793 const EVP_MD *md = ssl_handshake_md(s);
794 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
795 unsigned int hashsize, datalen;
796 int ret = 0;
797
798 if (ctx == NULL || !ossl_statem_export_allowed(s))
799 goto err;
800
801 if (!use_context)
802 contextlen = 0;
803
804 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
805 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
806 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
807 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
808 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
809 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
810 (const unsigned char *)label, llen,
811 data, datalen, exportsecret, hashsize, 0)
812 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
813 sizeof(exporterlabel) - 1, hash, hashsize,
814 out, olen, 0))
815 goto err;
816
817 ret = 1;
818 err:
819 EVP_MD_CTX_free(ctx);
820 return ret;
821 }
822
tls13_export_keying_material_early(SSL * s,unsigned char * out,size_t olen,const char * label,size_t llen,const unsigned char * context,size_t contextlen)823 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
824 const char *label, size_t llen,
825 const unsigned char *context,
826 size_t contextlen)
827 {
828 #ifdef CHARSET_EBCDIC
829 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
830 #else
831 static const unsigned char exporterlabel[] = "exporter";
832 #endif
833 unsigned char exportsecret[EVP_MAX_MD_SIZE];
834 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
835 const EVP_MD *md;
836 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
837 unsigned int hashsize, datalen;
838 int ret = 0;
839 const SSL_CIPHER *sslcipher;
840
841 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
842 goto err;
843
844 if (!s->server && s->max_early_data > 0
845 && s->session->ext.max_early_data == 0)
846 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
847 else
848 sslcipher = SSL_SESSION_get0_cipher(s->session);
849
850 md = ssl_md(sslcipher->algorithm2);
851
852 /*
853 * Calculate the hash value and store it in |data|. The reason why
854 * the empty string is used is that the definition of TLS-Exporter
855 * is like so:
856 *
857 * TLS-Exporter(label, context_value, key_length) =
858 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
859 * "exporter", Hash(context_value), key_length)
860 *
861 * Derive-Secret(Secret, Label, Messages) =
862 * HKDF-Expand-Label(Secret, Label,
863 * Transcript-Hash(Messages), Hash.length)
864 *
865 * Here Transcript-Hash is the cipher suite hash algorithm.
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->early_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