1 /*
2 * Copyright 2016-2020 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 return 0;
194 }
195 mdlen = (size_t)mdleni;
196
197 if (insecret == NULL) {
198 insecret = default_zeros;
199 insecretlen = mdlen;
200 }
201 if (prevsecret == NULL) {
202 prevsecret = default_zeros;
203 prevsecretlen = 0;
204 } else {
205 EVP_MD_CTX *mctx = EVP_MD_CTX_new();
206 unsigned char hash[EVP_MAX_MD_SIZE];
207
208 /* The pre-extract derive step uses a hash of no messages */
209 if (mctx == NULL
210 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
211 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
212 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
213 ERR_R_INTERNAL_ERROR);
214 EVP_MD_CTX_free(mctx);
215 EVP_PKEY_CTX_free(pctx);
216 return 0;
217 }
218 EVP_MD_CTX_free(mctx);
219
220 /* Generate the pre-extract secret */
221 if (!tls13_hkdf_expand(s, md, prevsecret,
222 (unsigned char *)derived_secret_label,
223 sizeof(derived_secret_label) - 1, hash, mdlen,
224 preextractsec, mdlen, 1)) {
225 /* SSLfatal() already called */
226 EVP_PKEY_CTX_free(pctx);
227 return 0;
228 }
229
230 prevsecret = preextractsec;
231 prevsecretlen = mdlen;
232 }
233
234 ret = EVP_PKEY_derive_init(pctx) <= 0
235 || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY)
236 <= 0
237 || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
238 || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0
239 || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen)
240 <= 0
241 || EVP_PKEY_derive(pctx, outsecret, &mdlen)
242 <= 0;
243
244 if (ret != 0)
245 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
246 ERR_R_INTERNAL_ERROR);
247
248 EVP_PKEY_CTX_free(pctx);
249 if (prevsecret == preextractsec)
250 OPENSSL_cleanse(preextractsec, mdlen);
251 return ret == 0;
252 }
253
254 /*
255 * Given an input secret |insecret| of length |insecretlen| generate the
256 * handshake secret. This requires the early secret to already have been
257 * generated. Returns 1 on success 0 on failure.
258 */
tls13_generate_handshake_secret(SSL * s,const unsigned char * insecret,size_t insecretlen)259 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
260 size_t insecretlen)
261 {
262 /* Calls SSLfatal() if required */
263 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
264 insecret, insecretlen,
265 (unsigned char *)&s->handshake_secret);
266 }
267
268 /*
269 * Given the handshake secret |prev| of length |prevlen| generate the master
270 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
271 * failure.
272 */
tls13_generate_master_secret(SSL * s,unsigned char * out,unsigned char * prev,size_t prevlen,size_t * secret_size)273 int tls13_generate_master_secret(SSL *s, unsigned char *out,
274 unsigned char *prev, size_t prevlen,
275 size_t *secret_size)
276 {
277 const EVP_MD *md = ssl_handshake_md(s);
278
279 *secret_size = EVP_MD_size(md);
280 /* Calls SSLfatal() if required */
281 return tls13_generate_secret(s, md, prev, NULL, 0, out);
282 }
283
284 /*
285 * Generates the mac for the Finished message. Returns the length of the MAC or
286 * 0 on error.
287 */
tls13_final_finish_mac(SSL * s,const char * str,size_t slen,unsigned char * out)288 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
289 unsigned char *out)
290 {
291 const EVP_MD *md = ssl_handshake_md(s);
292 unsigned char hash[EVP_MAX_MD_SIZE];
293 size_t hashlen, ret = 0;
294 EVP_PKEY *key = NULL;
295 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
296
297 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
298 /* SSLfatal() already called */
299 goto err;
300 }
301
302 if (str == s->method->ssl3_enc->server_finished_label) {
303 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
304 s->server_finished_secret, hashlen);
305 } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
306 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
307 s->client_finished_secret, hashlen);
308 } else {
309 unsigned char finsecret[EVP_MAX_MD_SIZE];
310
311 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
312 s->client_app_traffic_secret,
313 finsecret, hashlen))
314 goto err;
315
316 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret,
317 hashlen);
318 OPENSSL_cleanse(finsecret, sizeof(finsecret));
319 }
320
321 if (key == NULL
322 || ctx == NULL
323 || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0
324 || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0
325 || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) {
326 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
327 ERR_R_INTERNAL_ERROR);
328 goto err;
329 }
330
331 ret = hashlen;
332 err:
333 EVP_PKEY_free(key);
334 EVP_MD_CTX_free(ctx);
335 return ret;
336 }
337
338 /*
339 * There isn't really a key block in TLSv1.3, but we still need this function
340 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
341 */
tls13_setup_key_block(SSL * s)342 int tls13_setup_key_block(SSL *s)
343 {
344 const EVP_CIPHER *c;
345 const EVP_MD *hash;
346
347 s->session->cipher = s->s3->tmp.new_cipher;
348 if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) {
349 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK,
350 SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
351 return 0;
352 }
353
354 s->s3->tmp.new_sym_enc = c;
355 s->s3->tmp.new_hash = hash;
356
357 return 1;
358 }
359
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)360 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
361 const EVP_CIPHER *ciph,
362 const unsigned char *insecret,
363 const unsigned char *hash,
364 const unsigned char *label,
365 size_t labellen, unsigned char *secret,
366 unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx)
367 {
368 unsigned char key[EVP_MAX_KEY_LENGTH];
369 size_t ivlen, keylen, taglen;
370 int hashleni = EVP_MD_size(md);
371 size_t hashlen;
372
373 /* Ensure cast to size_t is safe */
374 if (!ossl_assert(hashleni >= 0)) {
375 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
376 ERR_R_EVP_LIB);
377 goto err;
378 }
379 hashlen = (size_t)hashleni;
380
381 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
382 secret, hashlen, 1)) {
383 /* SSLfatal() already called */
384 goto err;
385 }
386
387 /* TODO(size_t): convert me */
388 keylen = EVP_CIPHER_key_length(ciph);
389 if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
390 uint32_t algenc;
391
392 ivlen = EVP_CCM_TLS_IV_LEN;
393 if (s->s3->tmp.new_cipher != NULL) {
394 algenc = s->s3->tmp.new_cipher->algorithm_enc;
395 } else if (s->session->cipher != NULL) {
396 /* We've not selected a cipher yet - we must be doing early data */
397 algenc = s->session->cipher->algorithm_enc;
398 } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
399 /* We must be doing early data with out-of-band PSK */
400 algenc = s->psksession->cipher->algorithm_enc;
401 } else {
402 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
403 ERR_R_EVP_LIB);
404 goto err;
405 }
406 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
407 taglen = EVP_CCM8_TLS_TAG_LEN;
408 else
409 taglen = EVP_CCM_TLS_TAG_LEN;
410 } else {
411 ivlen = EVP_CIPHER_iv_length(ciph);
412 taglen = 0;
413 }
414
415 if (!tls13_derive_key(s, md, secret, key, keylen)
416 || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
417 /* SSLfatal() already called */
418 goto err;
419 }
420
421 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
422 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
423 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
424 taglen, NULL))
425 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
426 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
427 ERR_R_EVP_LIB);
428 goto err;
429 }
430
431 return 1;
432 err:
433 OPENSSL_cleanse(key, sizeof(key));
434 return 0;
435 }
436
tls13_change_cipher_state(SSL * s,int which)437 int tls13_change_cipher_state(SSL *s, int which)
438 {
439 #ifdef CHARSET_EBCDIC
440 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
441 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
442 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
443 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
444 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
445 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
446 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
447 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
448 #else
449 static const unsigned char client_early_traffic[] = "c e traffic";
450 static const unsigned char client_handshake_traffic[] = "c hs traffic";
451 static const unsigned char client_application_traffic[] = "c ap traffic";
452 static const unsigned char server_handshake_traffic[] = "s hs traffic";
453 static const unsigned char server_application_traffic[] = "s ap traffic";
454 static const unsigned char exporter_master_secret[] = "exp master";
455 static const unsigned char resumption_master_secret[] = "res master";
456 static const unsigned char early_exporter_master_secret[] = "e exp master";
457 #endif
458 unsigned char *iv;
459 unsigned char secret[EVP_MAX_MD_SIZE];
460 unsigned char hashval[EVP_MAX_MD_SIZE];
461 unsigned char *hash = hashval;
462 unsigned char *insecret;
463 unsigned char *finsecret = NULL;
464 const char *log_label = NULL;
465 EVP_CIPHER_CTX *ciph_ctx;
466 size_t finsecretlen = 0;
467 const unsigned char *label;
468 size_t labellen, hashlen = 0;
469 int ret = 0;
470 const EVP_MD *md = NULL;
471 const EVP_CIPHER *cipher = NULL;
472
473 if (which & SSL3_CC_READ) {
474 if (s->enc_read_ctx != NULL) {
475 EVP_CIPHER_CTX_reset(s->enc_read_ctx);
476 } else {
477 s->enc_read_ctx = EVP_CIPHER_CTX_new();
478 if (s->enc_read_ctx == NULL) {
479 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
480 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
481 goto err;
482 }
483 }
484 ciph_ctx = s->enc_read_ctx;
485 iv = s->read_iv;
486
487 RECORD_LAYER_reset_read_sequence(&s->rlayer);
488 } else {
489 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
490 if (s->enc_write_ctx != NULL) {
491 EVP_CIPHER_CTX_reset(s->enc_write_ctx);
492 } else {
493 s->enc_write_ctx = EVP_CIPHER_CTX_new();
494 if (s->enc_write_ctx == NULL) {
495 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
496 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
497 goto err;
498 }
499 }
500 ciph_ctx = s->enc_write_ctx;
501 iv = s->write_iv;
502
503 RECORD_LAYER_reset_write_sequence(&s->rlayer);
504 }
505
506 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
507 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
508 if (which & SSL3_CC_EARLY) {
509 EVP_MD_CTX *mdctx = NULL;
510 long handlen;
511 void *hdata;
512 unsigned int hashlenui;
513 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
514
515 insecret = s->early_secret;
516 label = client_early_traffic;
517 labellen = sizeof(client_early_traffic) - 1;
518 log_label = CLIENT_EARLY_LABEL;
519
520 handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
521 if (handlen <= 0) {
522 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
523 SSL_F_TLS13_CHANGE_CIPHER_STATE,
524 SSL_R_BAD_HANDSHAKE_LENGTH);
525 goto err;
526 }
527
528 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
529 && s->max_early_data > 0
530 && s->session->ext.max_early_data == 0) {
531 /*
532 * If we are attempting to send early data, and we've decided to
533 * actually do it but max_early_data in s->session is 0 then we
534 * must be using an external PSK.
535 */
536 if (!ossl_assert(s->psksession != NULL
537 && s->max_early_data ==
538 s->psksession->ext.max_early_data)) {
539 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
540 SSL_F_TLS13_CHANGE_CIPHER_STATE,
541 ERR_R_INTERNAL_ERROR);
542 goto err;
543 }
544 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
545 }
546 if (sslcipher == NULL) {
547 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
548 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK);
549 goto err;
550 }
551
552 /*
553 * We need to calculate the handshake digest using the digest from
554 * the session. We haven't yet selected our ciphersuite so we can't
555 * use ssl_handshake_md().
556 */
557 mdctx = EVP_MD_CTX_new();
558 if (mdctx == NULL) {
559 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
560 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
561 goto err;
562 }
563 cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher));
564 md = ssl_md(sslcipher->algorithm2);
565 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
566 || !EVP_DigestUpdate(mdctx, hdata, handlen)
567 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
568 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
569 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
570 EVP_MD_CTX_free(mdctx);
571 goto err;
572 }
573 hashlen = hashlenui;
574 EVP_MD_CTX_free(mdctx);
575
576 if (!tls13_hkdf_expand(s, md, insecret,
577 early_exporter_master_secret,
578 sizeof(early_exporter_master_secret) - 1,
579 hashval, hashlen,
580 s->early_exporter_master_secret, hashlen,
581 1)) {
582 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
583 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
584 goto err;
585 }
586
587 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
588 s->early_exporter_master_secret, hashlen)) {
589 /* SSLfatal() already called */
590 goto err;
591 }
592 } else if (which & SSL3_CC_HANDSHAKE) {
593 insecret = s->handshake_secret;
594 finsecret = s->client_finished_secret;
595 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
596 label = client_handshake_traffic;
597 labellen = sizeof(client_handshake_traffic) - 1;
598 log_label = CLIENT_HANDSHAKE_LABEL;
599 /*
600 * The handshake hash used for the server read/client write handshake
601 * traffic secret is the same as the hash for the server
602 * write/client read handshake traffic secret. However, if we
603 * processed early data then we delay changing the server
604 * read/client write cipher state until later, and the handshake
605 * hashes have moved on. Therefore we use the value saved earlier
606 * when we did the server write/client read change cipher state.
607 */
608 hash = s->handshake_traffic_hash;
609 } else {
610 insecret = s->master_secret;
611 label = client_application_traffic;
612 labellen = sizeof(client_application_traffic) - 1;
613 log_label = CLIENT_APPLICATION_LABEL;
614 /*
615 * For this we only use the handshake hashes up until the server
616 * Finished hash. We do not include the client's Finished, which is
617 * what ssl_handshake_hash() would give us. Instead we use the
618 * previously saved value.
619 */
620 hash = s->server_finished_hash;
621 }
622 } else {
623 /* Early data never applies to client-read/server-write */
624 if (which & SSL3_CC_HANDSHAKE) {
625 insecret = s->handshake_secret;
626 finsecret = s->server_finished_secret;
627 finsecretlen = EVP_MD_size(ssl_handshake_md(s));
628 label = server_handshake_traffic;
629 labellen = sizeof(server_handshake_traffic) - 1;
630 log_label = SERVER_HANDSHAKE_LABEL;
631 } else {
632 insecret = s->master_secret;
633 label = server_application_traffic;
634 labellen = sizeof(server_application_traffic) - 1;
635 log_label = SERVER_APPLICATION_LABEL;
636 }
637 }
638
639 if (!(which & SSL3_CC_EARLY)) {
640 md = ssl_handshake_md(s);
641 cipher = s->s3->tmp.new_sym_enc;
642 if (!ssl3_digest_cached_records(s, 1)
643 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
644 /* SSLfatal() already called */;
645 goto err;
646 }
647 }
648
649 /*
650 * Save the hash of handshakes up to now for use when we calculate the
651 * client application traffic secret
652 */
653 if (label == server_application_traffic)
654 memcpy(s->server_finished_hash, hashval, hashlen);
655
656 if (label == server_handshake_traffic)
657 memcpy(s->handshake_traffic_hash, hashval, hashlen);
658
659 if (label == client_application_traffic) {
660 /*
661 * We also create the resumption master secret, but this time use the
662 * hash for the whole handshake including the Client Finished
663 */
664 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
665 resumption_master_secret,
666 sizeof(resumption_master_secret) - 1,
667 hashval, hashlen, s->resumption_master_secret,
668 hashlen, 1)) {
669 /* SSLfatal() already called */
670 goto err;
671 }
672 }
673
674 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
675 insecret, hash, label, labellen, secret, iv,
676 ciph_ctx)) {
677 /* SSLfatal() already called */
678 goto err;
679 }
680
681 if (label == server_application_traffic) {
682 memcpy(s->server_app_traffic_secret, secret, hashlen);
683 /* Now we create the exporter master secret */
684 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
685 exporter_master_secret,
686 sizeof(exporter_master_secret) - 1,
687 hash, hashlen, s->exporter_master_secret,
688 hashlen, 1)) {
689 /* SSLfatal() already called */
690 goto err;
691 }
692
693 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
694 hashlen)) {
695 /* SSLfatal() already called */
696 goto err;
697 }
698 } else if (label == client_application_traffic)
699 memcpy(s->client_app_traffic_secret, secret, hashlen);
700
701 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
702 /* SSLfatal() already called */
703 goto err;
704 }
705
706 if (finsecret != NULL
707 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
708 finsecret, finsecretlen)) {
709 /* SSLfatal() already called */
710 goto err;
711 }
712
713 if (!s->server && label == client_early_traffic)
714 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
715 else
716 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
717 ret = 1;
718 err:
719 OPENSSL_cleanse(secret, sizeof(secret));
720 return ret;
721 }
722
tls13_update_key(SSL * s,int sending)723 int tls13_update_key(SSL *s, int sending)
724 {
725 #ifdef CHARSET_EBCDIC
726 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
727 #else
728 static const unsigned char application_traffic[] = "traffic upd";
729 #endif
730 const EVP_MD *md = ssl_handshake_md(s);
731 size_t hashlen = EVP_MD_size(md);
732 unsigned char *insecret, *iv;
733 unsigned char secret[EVP_MAX_MD_SIZE];
734 EVP_CIPHER_CTX *ciph_ctx;
735 int ret = 0;
736
737 if (s->server == sending)
738 insecret = s->server_app_traffic_secret;
739 else
740 insecret = s->client_app_traffic_secret;
741
742 if (sending) {
743 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
744 iv = s->write_iv;
745 ciph_ctx = s->enc_write_ctx;
746 RECORD_LAYER_reset_write_sequence(&s->rlayer);
747 } else {
748 iv = s->read_iv;
749 ciph_ctx = s->enc_read_ctx;
750 RECORD_LAYER_reset_read_sequence(&s->rlayer);
751 }
752
753 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
754 s->s3->tmp.new_sym_enc, insecret, NULL,
755 application_traffic,
756 sizeof(application_traffic) - 1, secret, iv,
757 ciph_ctx)) {
758 /* SSLfatal() already called */
759 goto err;
760 }
761
762 memcpy(insecret, secret, hashlen);
763
764 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
765 ret = 1;
766 err:
767 OPENSSL_cleanse(secret, sizeof(secret));
768 return ret;
769 }
770
tls13_alert_code(int code)771 int tls13_alert_code(int code)
772 {
773 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
774 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
775 return code;
776
777 return tls1_alert_code(code);
778 }
779
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)780 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
781 const char *label, size_t llen,
782 const unsigned char *context,
783 size_t contextlen, int use_context)
784 {
785 unsigned char exportsecret[EVP_MAX_MD_SIZE];
786 #ifdef CHARSET_EBCDIC
787 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
788 #else
789 static const unsigned char exporterlabel[] = "exporter";
790 #endif
791 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
792 const EVP_MD *md = ssl_handshake_md(s);
793 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
794 unsigned int hashsize, datalen;
795 int ret = 0;
796
797 if (ctx == NULL || !ossl_statem_export_allowed(s))
798 goto err;
799
800 if (!use_context)
801 contextlen = 0;
802
803 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
804 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
805 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
806 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
807 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
808 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
809 (const unsigned char *)label, llen,
810 data, datalen, exportsecret, hashsize, 0)
811 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
812 sizeof(exporterlabel) - 1, hash, hashsize,
813 out, olen, 0))
814 goto err;
815
816 ret = 1;
817 err:
818 EVP_MD_CTX_free(ctx);
819 return ret;
820 }
821
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)822 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
823 const char *label, size_t llen,
824 const unsigned char *context,
825 size_t contextlen)
826 {
827 #ifdef CHARSET_EBCDIC
828 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
829 #else
830 static const unsigned char exporterlabel[] = "exporter";
831 #endif
832 unsigned char exportsecret[EVP_MAX_MD_SIZE];
833 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
834 const EVP_MD *md;
835 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
836 unsigned int hashsize, datalen;
837 int ret = 0;
838 const SSL_CIPHER *sslcipher;
839
840 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
841 goto err;
842
843 if (!s->server && s->max_early_data > 0
844 && s->session->ext.max_early_data == 0)
845 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
846 else
847 sslcipher = SSL_SESSION_get0_cipher(s->session);
848
849 md = ssl_md(sslcipher->algorithm2);
850
851 /*
852 * Calculate the hash value and store it in |data|. The reason why
853 * the empty string is used is that the definition of TLS-Exporter
854 * is like so:
855 *
856 * TLS-Exporter(label, context_value, key_length) =
857 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
858 * "exporter", Hash(context_value), key_length)
859 *
860 * Derive-Secret(Secret, Label, Messages) =
861 * HKDF-Expand-Label(Secret, Label,
862 * Transcript-Hash(Messages), Hash.length)
863 *
864 * Here Transcript-Hash is the cipher suite hash algorithm.
865 */
866 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
867 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
868 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
869 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
870 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
871 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
872 (const unsigned char *)label, llen,
873 data, datalen, exportsecret, hashsize, 0)
874 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
875 sizeof(exporterlabel) - 1, hash, hashsize,
876 out, olen, 0))
877 goto err;
878
879 ret = 1;
880 err:
881 EVP_MD_CTX_free(ctx);
882 return ret;
883 }
884