1 /*
2 * Copyright 2016-2022 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 #ifdef CHARSET_EBCDIC
22 static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 };
23 #else
24 static const unsigned char label_prefix[] = "tls13 ";
25 #endif
26
27 /*
28 * Given a |secret|; a |label| of length |labellen|; and |data| of length
29 * |datalen| (e.g. typically a hash of the handshake messages), derive a new
30 * secret |outlen| bytes long and store it in the location pointed to be |out|.
31 * The |data| value may be zero length. Any errors will be treated as fatal if
32 * |fatal| is set. Returns 1 on success 0 on failure.
33 */
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)34 int tls13_hkdf_expand(SSL *s, const EVP_MD *md, 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 fatal)
38 {
39 EVP_KDF *kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_TLS1_3_KDF,
40 s->ctx->propq);
41 EVP_KDF_CTX *kctx;
42 OSSL_PARAM params[7], *p = params;
43 int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY;
44 const char *mdname = EVP_MD_get0_name(md);
45 int ret;
46 size_t hashlen;
47
48 kctx = EVP_KDF_CTX_new(kdf);
49 EVP_KDF_free(kdf);
50 if (kctx == NULL)
51 return 0;
52
53 if (labellen > TLS13_MAX_LABEL_LEN) {
54 if (fatal) {
55 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
56 } else {
57 /*
58 * Probably we have been called from SSL_export_keying_material(),
59 * or SSL_export_keying_material_early().
60 */
61 ERR_raise(ERR_LIB_SSL, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
62 }
63 EVP_KDF_CTX_free(kctx);
64 return 0;
65 }
66
67 if ((ret = EVP_MD_get_size(md)) <= 0) {
68 EVP_KDF_CTX_free(kctx);
69 if (fatal)
70 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
71 else
72 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
73 return 0;
74 }
75 hashlen = (size_t)ret;
76
77 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
78 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
79 (char *)mdname, 0);
80 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
81 (unsigned char *)secret, hashlen);
82 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
83 (unsigned char *)label_prefix,
84 sizeof(label_prefix) - 1);
85 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
86 (unsigned char *)label, labellen);
87 if (data != NULL)
88 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_DATA,
89 (unsigned char *)data,
90 datalen);
91 *p++ = OSSL_PARAM_construct_end();
92
93 ret = EVP_KDF_derive(kctx, out, outlen, params) <= 0;
94 EVP_KDF_CTX_free(kctx);
95
96 if (ret != 0) {
97 if (fatal)
98 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
99 else
100 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
101 }
102
103 return ret == 0;
104 }
105
106 /*
107 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
108 * success 0 on failure.
109 */
tls13_derive_key(SSL * s,const EVP_MD * md,const unsigned char * secret,unsigned char * key,size_t keylen)110 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
111 unsigned char *key, size_t keylen)
112 {
113 #ifdef CHARSET_EBCDIC
114 static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 };
115 #else
116 static const unsigned char keylabel[] = "key";
117 #endif
118
119 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
120 NULL, 0, key, keylen, 1);
121 }
122
123 /*
124 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
125 * success 0 on failure.
126 */
tls13_derive_iv(SSL * s,const EVP_MD * md,const unsigned char * secret,unsigned char * iv,size_t ivlen)127 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
128 unsigned char *iv, size_t ivlen)
129 {
130 #ifdef CHARSET_EBCDIC
131 static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 };
132 #else
133 static const unsigned char ivlabel[] = "iv";
134 #endif
135
136 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
137 NULL, 0, iv, ivlen, 1);
138 }
139
tls13_derive_finishedkey(SSL * s,const EVP_MD * md,const unsigned char * secret,unsigned char * fin,size_t finlen)140 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
141 const unsigned char *secret,
142 unsigned char *fin, size_t finlen)
143 {
144 #ifdef CHARSET_EBCDIC
145 static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 };
146 #else
147 static const unsigned char finishedlabel[] = "finished";
148 #endif
149
150 return tls13_hkdf_expand(s, md, secret, finishedlabel,
151 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
152 }
153
154 /*
155 * Given the previous secret |prevsecret| and a new input secret |insecret| of
156 * length |insecretlen|, generate a new secret and store it in the location
157 * pointed to by |outsecret|. Returns 1 on success 0 on failure.
158 */
tls13_generate_secret(SSL * s,const EVP_MD * md,const unsigned char * prevsecret,const unsigned char * insecret,size_t insecretlen,unsigned char * outsecret)159 int tls13_generate_secret(SSL *s, const EVP_MD *md,
160 const unsigned char *prevsecret,
161 const unsigned char *insecret,
162 size_t insecretlen,
163 unsigned char *outsecret)
164 {
165 size_t mdlen;
166 int mdleni;
167 int ret;
168 EVP_KDF *kdf;
169 EVP_KDF_CTX *kctx;
170 OSSL_PARAM params[7], *p = params;
171 int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
172 const char *mdname = EVP_MD_get0_name(md);
173 #ifdef CHARSET_EBCDIC
174 static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 };
175 #else
176 static const char derived_secret_label[] = "derived";
177 #endif
178
179 kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_TLS1_3_KDF, s->ctx->propq);
180 kctx = EVP_KDF_CTX_new(kdf);
181 EVP_KDF_free(kdf);
182 if (kctx == NULL) {
183 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
184 return 0;
185 }
186
187 mdleni = EVP_MD_get_size(md);
188 /* Ensure cast to size_t is safe */
189 if (!ossl_assert(mdleni >= 0)) {
190 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
191 EVP_KDF_CTX_free(kctx);
192 return 0;
193 }
194 mdlen = (size_t)mdleni;
195
196 *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
197 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
198 (char *)mdname, 0);
199 if (insecret != NULL)
200 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
201 (unsigned char *)insecret,
202 insecretlen);
203 if (prevsecret != NULL)
204 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
205 (unsigned char *)prevsecret, mdlen);
206 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
207 (unsigned char *)label_prefix,
208 sizeof(label_prefix) - 1);
209 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
210 (unsigned char *)derived_secret_label,
211 sizeof(derived_secret_label) - 1);
212 *p++ = OSSL_PARAM_construct_end();
213
214 ret = EVP_KDF_derive(kctx, outsecret, mdlen, params) <= 0;
215
216 if (ret != 0)
217 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
218
219 EVP_KDF_CTX_free(kctx);
220 return ret == 0;
221 }
222
223 /*
224 * Given an input secret |insecret| of length |insecretlen| generate the
225 * handshake secret. This requires the early secret to already have been
226 * generated. Returns 1 on success 0 on failure.
227 */
tls13_generate_handshake_secret(SSL * s,const unsigned char * insecret,size_t insecretlen)228 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
229 size_t insecretlen)
230 {
231 /* Calls SSLfatal() if required */
232 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
233 insecret, insecretlen,
234 (unsigned char *)&s->handshake_secret);
235 }
236
237 /*
238 * Given the handshake secret |prev| of length |prevlen| generate the master
239 * secret and store its length in |*secret_size|. Returns 1 on success 0 on
240 * failure.
241 */
tls13_generate_master_secret(SSL * s,unsigned char * out,unsigned char * prev,size_t prevlen,size_t * secret_size)242 int tls13_generate_master_secret(SSL *s, unsigned char *out,
243 unsigned char *prev, size_t prevlen,
244 size_t *secret_size)
245 {
246 const EVP_MD *md = ssl_handshake_md(s);
247
248 *secret_size = EVP_MD_get_size(md);
249 /* Calls SSLfatal() if required */
250 return tls13_generate_secret(s, md, prev, NULL, 0, out);
251 }
252
253 /*
254 * Generates the mac for the Finished message. Returns the length of the MAC or
255 * 0 on error.
256 */
tls13_final_finish_mac(SSL * s,const char * str,size_t slen,unsigned char * out)257 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
258 unsigned char *out)
259 {
260 const EVP_MD *md = ssl_handshake_md(s);
261 const char *mdname = EVP_MD_get0_name(md);
262 unsigned char hash[EVP_MAX_MD_SIZE];
263 unsigned char finsecret[EVP_MAX_MD_SIZE];
264 unsigned char *key = NULL;
265 size_t len = 0, hashlen;
266 OSSL_PARAM params[2], *p = params;
267
268 if (md == NULL)
269 return 0;
270
271 /* Safe to cast away const here since we're not "getting" any data */
272 if (s->ctx->propq != NULL)
273 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
274 (char *)s->ctx->propq,
275 0);
276 *p = OSSL_PARAM_construct_end();
277
278 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
279 /* SSLfatal() already called */
280 goto err;
281 }
282
283 if (str == s->method->ssl3_enc->server_finished_label) {
284 key = s->server_finished_secret;
285 } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
286 key = s->client_finished_secret;
287 } else {
288 if (!tls13_derive_finishedkey(s, md,
289 s->client_app_traffic_secret,
290 finsecret, hashlen))
291 goto err;
292 key = finsecret;
293 }
294
295 if (!EVP_Q_mac(s->ctx->libctx, "HMAC", s->ctx->propq, mdname,
296 params, key, hashlen, hash, hashlen,
297 /* outsize as per sizeof(peer_finish_md) */
298 out, EVP_MAX_MD_SIZE * 2, &len)) {
299 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
300 goto err;
301 }
302
303 err:
304 OPENSSL_cleanse(finsecret, sizeof(finsecret));
305 return len;
306 }
307
308 /*
309 * There isn't really a key block in TLSv1.3, but we still need this function
310 * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
311 */
tls13_setup_key_block(SSL * s)312 int tls13_setup_key_block(SSL *s)
313 {
314 const EVP_CIPHER *c;
315 const EVP_MD *hash;
316
317 s->session->cipher = s->s3.tmp.new_cipher;
318 if (!ssl_cipher_get_evp(s->ctx, s->session, &c, &hash, NULL, NULL, NULL,
319 0)) {
320 /* Error is already recorded */
321 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
322 return 0;
323 }
324
325 ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
326 s->s3.tmp.new_sym_enc = c;
327 ssl_evp_md_free(s->s3.tmp.new_hash);
328 s->s3.tmp.new_hash = hash;
329
330 return 1;
331 }
332
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 * key,unsigned char * iv,EVP_CIPHER_CTX * ciph_ctx)333 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
334 const EVP_CIPHER *ciph,
335 const unsigned char *insecret,
336 const unsigned char *hash,
337 const unsigned char *label,
338 size_t labellen, unsigned char *secret,
339 unsigned char *key, unsigned char *iv,
340 EVP_CIPHER_CTX *ciph_ctx)
341 {
342 size_t ivlen, keylen, taglen;
343 int hashleni = EVP_MD_get_size(md);
344 size_t hashlen;
345
346 /* Ensure cast to size_t is safe */
347 if (!ossl_assert(hashleni >= 0)) {
348 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
349 return 0;
350 }
351 hashlen = (size_t)hashleni;
352
353 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
354 secret, hashlen, 1)) {
355 /* SSLfatal() already called */
356 return 0;
357 }
358
359 keylen = EVP_CIPHER_get_key_length(ciph);
360 if (EVP_CIPHER_get_mode(ciph) == EVP_CIPH_CCM_MODE) {
361 uint32_t algenc;
362
363 ivlen = EVP_CCM_TLS_IV_LEN;
364 if (s->s3.tmp.new_cipher != NULL) {
365 algenc = s->s3.tmp.new_cipher->algorithm_enc;
366 } else if (s->session->cipher != NULL) {
367 /* We've not selected a cipher yet - we must be doing early data */
368 algenc = s->session->cipher->algorithm_enc;
369 } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
370 /* We must be doing early data with out-of-band PSK */
371 algenc = s->psksession->cipher->algorithm_enc;
372 } else {
373 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
374 return 0;
375 }
376 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
377 taglen = EVP_CCM8_TLS_TAG_LEN;
378 else
379 taglen = EVP_CCM_TLS_TAG_LEN;
380 } else {
381 ivlen = EVP_CIPHER_get_iv_length(ciph);
382 taglen = 0;
383 }
384
385 if (!tls13_derive_key(s, md, secret, key, keylen)
386 || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
387 /* SSLfatal() already called */
388 return 0;
389 }
390
391 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
392 || EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) <= 0
393 || (taglen != 0 && EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
394 taglen, NULL) <= 0)
395 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
396 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
397 return 0;
398 }
399
400 return 1;
401 }
402
tls13_change_cipher_state(SSL * s,int which)403 int tls13_change_cipher_state(SSL *s, int which)
404 {
405 #ifdef CHARSET_EBCDIC
406 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
407 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
408 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
409 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
410 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
411 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
412 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
413 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
414 #else
415 static const unsigned char client_early_traffic[] = "c e traffic";
416 static const unsigned char client_handshake_traffic[] = "c hs traffic";
417 static const unsigned char client_application_traffic[] = "c ap traffic";
418 static const unsigned char server_handshake_traffic[] = "s hs traffic";
419 static const unsigned char server_application_traffic[] = "s ap traffic";
420 static const unsigned char exporter_master_secret[] = "exp master";
421 static const unsigned char resumption_master_secret[] = "res master";
422 static const unsigned char early_exporter_master_secret[] = "e exp master";
423 #endif
424 unsigned char *iv;
425 unsigned char key[EVP_MAX_KEY_LENGTH];
426 unsigned char secret[EVP_MAX_MD_SIZE];
427 unsigned char hashval[EVP_MAX_MD_SIZE];
428 unsigned char *hash = hashval;
429 unsigned char *insecret;
430 unsigned char *finsecret = NULL;
431 const char *log_label = NULL;
432 EVP_CIPHER_CTX *ciph_ctx;
433 size_t finsecretlen = 0;
434 const unsigned char *label;
435 size_t labellen, hashlen = 0;
436 int ret = 0;
437 const EVP_MD *md = NULL;
438 const EVP_CIPHER *cipher = NULL;
439 #if !defined(OPENSSL_NO_KTLS) && defined(OPENSSL_KTLS_TLS13)
440 ktls_crypto_info_t crypto_info;
441 BIO *bio;
442 #endif
443
444 if (which & SSL3_CC_READ) {
445 if (s->enc_read_ctx != NULL) {
446 EVP_CIPHER_CTX_reset(s->enc_read_ctx);
447 } else {
448 s->enc_read_ctx = EVP_CIPHER_CTX_new();
449 if (s->enc_read_ctx == NULL) {
450 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
451 goto err;
452 }
453 }
454 ciph_ctx = s->enc_read_ctx;
455 iv = s->read_iv;
456
457 RECORD_LAYER_reset_read_sequence(&s->rlayer);
458 } else {
459 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
460 if (s->enc_write_ctx != NULL) {
461 EVP_CIPHER_CTX_reset(s->enc_write_ctx);
462 } else {
463 s->enc_write_ctx = EVP_CIPHER_CTX_new();
464 if (s->enc_write_ctx == NULL) {
465 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
466 goto err;
467 }
468 }
469 ciph_ctx = s->enc_write_ctx;
470 iv = s->write_iv;
471
472 RECORD_LAYER_reset_write_sequence(&s->rlayer);
473 }
474
475 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
476 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
477 if (which & SSL3_CC_EARLY) {
478 EVP_MD_CTX *mdctx = NULL;
479 long handlen;
480 void *hdata;
481 unsigned int hashlenui;
482 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
483
484 insecret = s->early_secret;
485 label = client_early_traffic;
486 labellen = sizeof(client_early_traffic) - 1;
487 log_label = CLIENT_EARLY_LABEL;
488
489 handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
490 if (handlen <= 0) {
491 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
492 goto err;
493 }
494
495 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
496 && s->max_early_data > 0
497 && s->session->ext.max_early_data == 0) {
498 /*
499 * If we are attempting to send early data, and we've decided to
500 * actually do it but max_early_data in s->session is 0 then we
501 * must be using an external PSK.
502 */
503 if (!ossl_assert(s->psksession != NULL
504 && s->max_early_data ==
505 s->psksession->ext.max_early_data)) {
506 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
507 goto err;
508 }
509 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
510 }
511 if (sslcipher == NULL) {
512 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
513 goto err;
514 }
515
516 /*
517 * We need to calculate the handshake digest using the digest from
518 * the session. We haven't yet selected our ciphersuite so we can't
519 * use ssl_handshake_md().
520 */
521 mdctx = EVP_MD_CTX_new();
522 if (mdctx == NULL) {
523 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
524 goto err;
525 }
526
527 /*
528 * This ups the ref count on cipher so we better make sure we free
529 * it again
530 */
531 if (!ssl_cipher_get_evp_cipher(s->ctx, sslcipher, &cipher)) {
532 /* Error is already recorded */
533 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
534 EVP_MD_CTX_free(mdctx);
535 goto err;
536 }
537
538 md = ssl_md(s->ctx, sslcipher->algorithm2);
539 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
540 || !EVP_DigestUpdate(mdctx, hdata, handlen)
541 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
542 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
543 EVP_MD_CTX_free(mdctx);
544 goto err;
545 }
546 hashlen = hashlenui;
547 EVP_MD_CTX_free(mdctx);
548
549 if (!tls13_hkdf_expand(s, md, insecret,
550 early_exporter_master_secret,
551 sizeof(early_exporter_master_secret) - 1,
552 hashval, hashlen,
553 s->early_exporter_master_secret, hashlen,
554 1)) {
555 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
556 goto err;
557 }
558
559 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
560 s->early_exporter_master_secret, hashlen)) {
561 /* SSLfatal() already called */
562 goto err;
563 }
564 } else if (which & SSL3_CC_HANDSHAKE) {
565 insecret = s->handshake_secret;
566 finsecret = s->client_finished_secret;
567 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
568 label = client_handshake_traffic;
569 labellen = sizeof(client_handshake_traffic) - 1;
570 log_label = CLIENT_HANDSHAKE_LABEL;
571 /*
572 * The handshake hash used for the server read/client write handshake
573 * traffic secret is the same as the hash for the server
574 * write/client read handshake traffic secret. However, if we
575 * processed early data then we delay changing the server
576 * read/client write cipher state until later, and the handshake
577 * hashes have moved on. Therefore we use the value saved earlier
578 * when we did the server write/client read change cipher state.
579 */
580 hash = s->handshake_traffic_hash;
581 } else {
582 insecret = s->master_secret;
583 label = client_application_traffic;
584 labellen = sizeof(client_application_traffic) - 1;
585 log_label = CLIENT_APPLICATION_LABEL;
586 /*
587 * For this we only use the handshake hashes up until the server
588 * Finished hash. We do not include the client's Finished, which is
589 * what ssl_handshake_hash() would give us. Instead we use the
590 * previously saved value.
591 */
592 hash = s->server_finished_hash;
593 }
594 } else {
595 /* Early data never applies to client-read/server-write */
596 if (which & SSL3_CC_HANDSHAKE) {
597 insecret = s->handshake_secret;
598 finsecret = s->server_finished_secret;
599 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
600 label = server_handshake_traffic;
601 labellen = sizeof(server_handshake_traffic) - 1;
602 log_label = SERVER_HANDSHAKE_LABEL;
603 } else {
604 insecret = s->master_secret;
605 label = server_application_traffic;
606 labellen = sizeof(server_application_traffic) - 1;
607 log_label = SERVER_APPLICATION_LABEL;
608 }
609 }
610
611 if (!(which & SSL3_CC_EARLY)) {
612 md = ssl_handshake_md(s);
613 cipher = s->s3.tmp.new_sym_enc;
614 if (!ssl3_digest_cached_records(s, 1)
615 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
616 /* SSLfatal() already called */;
617 goto err;
618 }
619 }
620
621 /*
622 * Save the hash of handshakes up to now for use when we calculate the
623 * client application traffic secret
624 */
625 if (label == server_application_traffic)
626 memcpy(s->server_finished_hash, hashval, hashlen);
627
628 if (label == server_handshake_traffic)
629 memcpy(s->handshake_traffic_hash, hashval, hashlen);
630
631 if (label == client_application_traffic) {
632 /*
633 * We also create the resumption master secret, but this time use the
634 * hash for the whole handshake including the Client Finished
635 */
636 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
637 resumption_master_secret,
638 sizeof(resumption_master_secret) - 1,
639 hashval, hashlen, s->resumption_master_secret,
640 hashlen, 1)) {
641 /* SSLfatal() already called */
642 goto err;
643 }
644 }
645
646 /* check whether cipher is known */
647 if(!ossl_assert(cipher != NULL))
648 goto err;
649
650 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
651 insecret, hash, label, labellen, secret, key,
652 iv, ciph_ctx)) {
653 /* SSLfatal() already called */
654 goto err;
655 }
656
657 if (label == server_application_traffic) {
658 memcpy(s->server_app_traffic_secret, secret, hashlen);
659 /* Now we create the exporter master secret */
660 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
661 exporter_master_secret,
662 sizeof(exporter_master_secret) - 1,
663 hash, hashlen, s->exporter_master_secret,
664 hashlen, 1)) {
665 /* SSLfatal() already called */
666 goto err;
667 }
668
669 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
670 hashlen)) {
671 /* SSLfatal() already called */
672 goto err;
673 }
674 } else if (label == client_application_traffic)
675 memcpy(s->client_app_traffic_secret, secret, hashlen);
676
677 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
678 /* SSLfatal() already called */
679 goto err;
680 }
681
682 if (finsecret != NULL
683 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
684 finsecret, finsecretlen)) {
685 /* SSLfatal() already called */
686 goto err;
687 }
688
689 if (!s->server && label == client_early_traffic)
690 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
691 else
692 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
693 #ifndef OPENSSL_NO_KTLS
694 # if defined(OPENSSL_KTLS_TLS13)
695 if (!(which & SSL3_CC_WRITE)
696 || !(which & SSL3_CC_APPLICATION)
697 || (s->options & SSL_OP_ENABLE_KTLS) == 0)
698 goto skip_ktls;
699
700 /* ktls supports only the maximum fragment size */
701 if (ssl_get_max_send_fragment(s) != SSL3_RT_MAX_PLAIN_LENGTH)
702 goto skip_ktls;
703
704 /* ktls does not support record padding */
705 if (s->record_padding_cb != NULL)
706 goto skip_ktls;
707
708 /* check that cipher is supported */
709 if (!ktls_check_supported_cipher(s, cipher, ciph_ctx))
710 goto skip_ktls;
711
712 bio = s->wbio;
713
714 if (!ossl_assert(bio != NULL)) {
715 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
716 goto err;
717 }
718
719 /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */
720 if (BIO_flush(bio) <= 0)
721 goto skip_ktls;
722
723 /* configure kernel crypto structure */
724 if (!ktls_configure_crypto(s, cipher, ciph_ctx,
725 RECORD_LAYER_get_write_sequence(&s->rlayer),
726 &crypto_info, NULL, iv, key, NULL, 0))
727 goto skip_ktls;
728
729 /* ktls works with user provided buffers directly */
730 if (BIO_set_ktls(bio, &crypto_info, which & SSL3_CC_WRITE))
731 ssl3_release_write_buffer(s);
732 skip_ktls:
733 # endif
734 #endif
735 ret = 1;
736 err:
737 if ((which & SSL3_CC_EARLY) != 0) {
738 /* We up-refed this so now we need to down ref */
739 ssl_evp_cipher_free(cipher);
740 }
741 OPENSSL_cleanse(key, sizeof(key));
742 OPENSSL_cleanse(secret, sizeof(secret));
743 return ret;
744 }
745
tls13_update_key(SSL * s,int sending)746 int tls13_update_key(SSL *s, int sending)
747 {
748 #ifdef CHARSET_EBCDIC
749 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
750 #else
751 static const unsigned char application_traffic[] = "traffic upd";
752 #endif
753 const EVP_MD *md = ssl_handshake_md(s);
754 size_t hashlen;
755 unsigned char key[EVP_MAX_KEY_LENGTH];
756 unsigned char *insecret, *iv;
757 unsigned char secret[EVP_MAX_MD_SIZE];
758 char *log_label;
759 EVP_CIPHER_CTX *ciph_ctx;
760 int ret = 0, l;
761
762 if ((l = EVP_MD_get_size(md)) <= 0) {
763 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
764 return 0;
765 }
766 hashlen = (size_t)l;
767
768 if (s->server == sending)
769 insecret = s->server_app_traffic_secret;
770 else
771 insecret = s->client_app_traffic_secret;
772
773 if (sending) {
774 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
775 iv = s->write_iv;
776 ciph_ctx = s->enc_write_ctx;
777 RECORD_LAYER_reset_write_sequence(&s->rlayer);
778 } else {
779 iv = s->read_iv;
780 ciph_ctx = s->enc_read_ctx;
781 RECORD_LAYER_reset_read_sequence(&s->rlayer);
782 }
783
784 if (!derive_secret_key_and_iv(s, sending, md,
785 s->s3.tmp.new_sym_enc, insecret, NULL,
786 application_traffic,
787 sizeof(application_traffic) - 1, secret, key,
788 iv, ciph_ctx)) {
789 /* SSLfatal() already called */
790 goto err;
791 }
792
793 memcpy(insecret, secret, hashlen);
794
795 /* Call Key log on successful traffic secret update */
796 log_label = s->server == sending ? SERVER_APPLICATION_N_LABEL : CLIENT_APPLICATION_N_LABEL;
797 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
798 /* SSLfatal() already called */
799 goto err;
800 }
801
802 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
803 ret = 1;
804 err:
805 OPENSSL_cleanse(key, sizeof(key));
806 OPENSSL_cleanse(secret, sizeof(secret));
807 return ret;
808 }
809
tls13_alert_code(int code)810 int tls13_alert_code(int code)
811 {
812 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
813 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
814 return code;
815
816 return tls1_alert_code(code);
817 }
818
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)819 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
820 const char *label, size_t llen,
821 const unsigned char *context,
822 size_t contextlen, int use_context)
823 {
824 unsigned char exportsecret[EVP_MAX_MD_SIZE];
825 #ifdef CHARSET_EBCDIC
826 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
827 #else
828 static const unsigned char exporterlabel[] = "exporter";
829 #endif
830 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
831 const EVP_MD *md = ssl_handshake_md(s);
832 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
833 unsigned int hashsize, datalen;
834 int ret = 0;
835
836 if (ctx == NULL || md == NULL || !ossl_statem_export_allowed(s))
837 goto err;
838
839 if (!use_context)
840 contextlen = 0;
841
842 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
843 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
844 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
845 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
846 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
847 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
848 (const unsigned char *)label, llen,
849 data, datalen, exportsecret, hashsize, 0)
850 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
851 sizeof(exporterlabel) - 1, hash, hashsize,
852 out, olen, 0))
853 goto err;
854
855 ret = 1;
856 err:
857 EVP_MD_CTX_free(ctx);
858 return ret;
859 }
860
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)861 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
862 const char *label, size_t llen,
863 const unsigned char *context,
864 size_t contextlen)
865 {
866 #ifdef CHARSET_EBCDIC
867 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
868 #else
869 static const unsigned char exporterlabel[] = "exporter";
870 #endif
871 unsigned char exportsecret[EVP_MAX_MD_SIZE];
872 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
873 const EVP_MD *md;
874 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
875 unsigned int hashsize, datalen;
876 int ret = 0;
877 const SSL_CIPHER *sslcipher;
878
879 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
880 goto err;
881
882 if (!s->server && s->max_early_data > 0
883 && s->session->ext.max_early_data == 0)
884 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
885 else
886 sslcipher = SSL_SESSION_get0_cipher(s->session);
887
888 md = ssl_md(s->ctx, sslcipher->algorithm2);
889
890 /*
891 * Calculate the hash value and store it in |data|. The reason why
892 * the empty string is used is that the definition of TLS-Exporter
893 * is like so:
894 *
895 * TLS-Exporter(label, context_value, key_length) =
896 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
897 * "exporter", Hash(context_value), key_length)
898 *
899 * Derive-Secret(Secret, Label, Messages) =
900 * HKDF-Expand-Label(Secret, Label,
901 * Transcript-Hash(Messages), Hash.length)
902 *
903 * Here Transcript-Hash is the cipher suite hash algorithm.
904 */
905 if (md == NULL
906 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
907 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
908 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
909 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
910 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
911 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
912 (const unsigned char *)label, llen,
913 data, datalen, exportsecret, hashsize, 0)
914 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
915 sizeof(exporterlabel) - 1, hash, hashsize,
916 out, olen, 0))
917 goto err;
918
919 ret = 1;
920 err:
921 EVP_MD_CTX_free(ctx);
922 return ret;
923 }
924