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 void *rl_sequence;
442 BIO *bio;
443 #endif
444
445 if (which & SSL3_CC_READ) {
446 if (s->enc_read_ctx != NULL) {
447 EVP_CIPHER_CTX_reset(s->enc_read_ctx);
448 } else {
449 s->enc_read_ctx = EVP_CIPHER_CTX_new();
450 if (s->enc_read_ctx == NULL) {
451 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
452 goto err;
453 }
454 }
455 ciph_ctx = s->enc_read_ctx;
456 iv = s->read_iv;
457
458 RECORD_LAYER_reset_read_sequence(&s->rlayer);
459 } else {
460 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
461 if (s->enc_write_ctx != NULL) {
462 EVP_CIPHER_CTX_reset(s->enc_write_ctx);
463 } else {
464 s->enc_write_ctx = EVP_CIPHER_CTX_new();
465 if (s->enc_write_ctx == NULL) {
466 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
467 goto err;
468 }
469 }
470 ciph_ctx = s->enc_write_ctx;
471 iv = s->write_iv;
472
473 RECORD_LAYER_reset_write_sequence(&s->rlayer);
474 }
475
476 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
477 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
478 if (which & SSL3_CC_EARLY) {
479 EVP_MD_CTX *mdctx = NULL;
480 long handlen;
481 void *hdata;
482 unsigned int hashlenui;
483 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
484
485 insecret = s->early_secret;
486 label = client_early_traffic;
487 labellen = sizeof(client_early_traffic) - 1;
488 log_label = CLIENT_EARLY_LABEL;
489
490 handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
491 if (handlen <= 0) {
492 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
493 goto err;
494 }
495
496 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
497 && s->max_early_data > 0
498 && s->session->ext.max_early_data == 0) {
499 /*
500 * If we are attempting to send early data, and we've decided to
501 * actually do it but max_early_data in s->session is 0 then we
502 * must be using an external PSK.
503 */
504 if (!ossl_assert(s->psksession != NULL
505 && s->max_early_data ==
506 s->psksession->ext.max_early_data)) {
507 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
508 goto err;
509 }
510 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
511 }
512 if (sslcipher == NULL) {
513 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
514 goto err;
515 }
516
517 /*
518 * We need to calculate the handshake digest using the digest from
519 * the session. We haven't yet selected our ciphersuite so we can't
520 * use ssl_handshake_md().
521 */
522 mdctx = EVP_MD_CTX_new();
523 if (mdctx == NULL) {
524 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
525 goto err;
526 }
527
528 /*
529 * This ups the ref count on cipher so we better make sure we free
530 * it again
531 */
532 if (!ssl_cipher_get_evp_cipher(s->ctx, sslcipher, &cipher)) {
533 /* Error is already recorded */
534 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
535 EVP_MD_CTX_free(mdctx);
536 goto err;
537 }
538
539 md = ssl_md(s->ctx, sslcipher->algorithm2);
540 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
541 || !EVP_DigestUpdate(mdctx, hdata, handlen)
542 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
543 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
544 EVP_MD_CTX_free(mdctx);
545 goto err;
546 }
547 hashlen = hashlenui;
548 EVP_MD_CTX_free(mdctx);
549
550 if (!tls13_hkdf_expand(s, md, insecret,
551 early_exporter_master_secret,
552 sizeof(early_exporter_master_secret) - 1,
553 hashval, hashlen,
554 s->early_exporter_master_secret, hashlen,
555 1)) {
556 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
557 goto err;
558 }
559
560 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
561 s->early_exporter_master_secret, hashlen)) {
562 /* SSLfatal() already called */
563 goto err;
564 }
565 } else if (which & SSL3_CC_HANDSHAKE) {
566 insecret = s->handshake_secret;
567 finsecret = s->client_finished_secret;
568 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
569 label = client_handshake_traffic;
570 labellen = sizeof(client_handshake_traffic) - 1;
571 log_label = CLIENT_HANDSHAKE_LABEL;
572 /*
573 * The handshake hash used for the server read/client write handshake
574 * traffic secret is the same as the hash for the server
575 * write/client read handshake traffic secret. However, if we
576 * processed early data then we delay changing the server
577 * read/client write cipher state until later, and the handshake
578 * hashes have moved on. Therefore we use the value saved earlier
579 * when we did the server write/client read change cipher state.
580 */
581 hash = s->handshake_traffic_hash;
582 } else {
583 insecret = s->master_secret;
584 label = client_application_traffic;
585 labellen = sizeof(client_application_traffic) - 1;
586 log_label = CLIENT_APPLICATION_LABEL;
587 /*
588 * For this we only use the handshake hashes up until the server
589 * Finished hash. We do not include the client's Finished, which is
590 * what ssl_handshake_hash() would give us. Instead we use the
591 * previously saved value.
592 */
593 hash = s->server_finished_hash;
594 }
595 } else {
596 /* Early data never applies to client-read/server-write */
597 if (which & SSL3_CC_HANDSHAKE) {
598 insecret = s->handshake_secret;
599 finsecret = s->server_finished_secret;
600 finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
601 label = server_handshake_traffic;
602 labellen = sizeof(server_handshake_traffic) - 1;
603 log_label = SERVER_HANDSHAKE_LABEL;
604 } else {
605 insecret = s->master_secret;
606 label = server_application_traffic;
607 labellen = sizeof(server_application_traffic) - 1;
608 log_label = SERVER_APPLICATION_LABEL;
609 }
610 }
611
612 if (!(which & SSL3_CC_EARLY)) {
613 md = ssl_handshake_md(s);
614 cipher = s->s3.tmp.new_sym_enc;
615 if (!ssl3_digest_cached_records(s, 1)
616 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
617 /* SSLfatal() already called */;
618 goto err;
619 }
620 }
621
622 /*
623 * Save the hash of handshakes up to now for use when we calculate the
624 * client application traffic secret
625 */
626 if (label == server_application_traffic)
627 memcpy(s->server_finished_hash, hashval, hashlen);
628
629 if (label == server_handshake_traffic)
630 memcpy(s->handshake_traffic_hash, hashval, hashlen);
631
632 if (label == client_application_traffic) {
633 /*
634 * We also create the resumption master secret, but this time use the
635 * hash for the whole handshake including the Client Finished
636 */
637 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
638 resumption_master_secret,
639 sizeof(resumption_master_secret) - 1,
640 hashval, hashlen, s->resumption_master_secret,
641 hashlen, 1)) {
642 /* SSLfatal() already called */
643 goto err;
644 }
645 }
646
647 /* check whether cipher is known */
648 if(!ossl_assert(cipher != NULL))
649 goto err;
650
651 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
652 insecret, hash, label, labellen, secret, key,
653 iv, ciph_ctx)) {
654 /* SSLfatal() already called */
655 goto err;
656 }
657
658 if (label == server_application_traffic) {
659 memcpy(s->server_app_traffic_secret, secret, hashlen);
660 /* Now we create the exporter master secret */
661 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
662 exporter_master_secret,
663 sizeof(exporter_master_secret) - 1,
664 hash, hashlen, s->exporter_master_secret,
665 hashlen, 1)) {
666 /* SSLfatal() already called */
667 goto err;
668 }
669
670 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
671 hashlen)) {
672 /* SSLfatal() already called */
673 goto err;
674 }
675 } else if (label == client_application_traffic)
676 memcpy(s->client_app_traffic_secret, secret, hashlen);
677
678 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
679 /* SSLfatal() already called */
680 goto err;
681 }
682
683 if (finsecret != NULL
684 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
685 finsecret, finsecretlen)) {
686 /* SSLfatal() already called */
687 goto err;
688 }
689
690 if (!s->server && label == client_early_traffic)
691 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
692 else
693 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
694 #ifndef OPENSSL_NO_KTLS
695 # if defined(OPENSSL_KTLS_TLS13)
696 if (!(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 if (which & SSL3_CC_WRITE)
713 bio = s->wbio;
714 else
715 bio = s->rbio;
716
717 if (!ossl_assert(bio != NULL)) {
718 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
719 goto err;
720 }
721
722 /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */
723 if (which & SSL3_CC_WRITE) {
724 if (BIO_flush(bio) <= 0)
725 goto skip_ktls;
726 }
727
728 /* configure kernel crypto structure */
729 if (which & SSL3_CC_WRITE)
730 rl_sequence = RECORD_LAYER_get_write_sequence(&s->rlayer);
731 else
732 rl_sequence = RECORD_LAYER_get_read_sequence(&s->rlayer);
733
734 if (!ktls_configure_crypto(s, cipher, ciph_ctx, rl_sequence, &crypto_info,
735 which & SSL3_CC_WRITE, iv, key, NULL, 0))
736 goto skip_ktls;
737
738 /* ktls works with user provided buffers directly */
739 if (BIO_set_ktls(bio, &crypto_info, which & SSL3_CC_WRITE)) {
740 if (which & SSL3_CC_WRITE)
741 ssl3_release_write_buffer(s);
742 }
743 skip_ktls:
744 # endif
745 #endif
746 ret = 1;
747 err:
748 if ((which & SSL3_CC_EARLY) != 0) {
749 /* We up-refed this so now we need to down ref */
750 ssl_evp_cipher_free(cipher);
751 }
752 OPENSSL_cleanse(key, sizeof(key));
753 OPENSSL_cleanse(secret, sizeof(secret));
754 return ret;
755 }
756
tls13_update_key(SSL * s,int sending)757 int tls13_update_key(SSL *s, int sending)
758 {
759 #ifdef CHARSET_EBCDIC
760 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
761 #else
762 static const unsigned char application_traffic[] = "traffic upd";
763 #endif
764 const EVP_MD *md = ssl_handshake_md(s);
765 size_t hashlen;
766 unsigned char key[EVP_MAX_KEY_LENGTH];
767 unsigned char *insecret, *iv;
768 unsigned char secret[EVP_MAX_MD_SIZE];
769 char *log_label;
770 EVP_CIPHER_CTX *ciph_ctx;
771 int ret = 0, l;
772
773 if ((l = EVP_MD_get_size(md)) <= 0) {
774 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
775 return 0;
776 }
777 hashlen = (size_t)l;
778
779 if (s->server == sending)
780 insecret = s->server_app_traffic_secret;
781 else
782 insecret = s->client_app_traffic_secret;
783
784 if (sending) {
785 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
786 iv = s->write_iv;
787 ciph_ctx = s->enc_write_ctx;
788 RECORD_LAYER_reset_write_sequence(&s->rlayer);
789 } else {
790 iv = s->read_iv;
791 ciph_ctx = s->enc_read_ctx;
792 RECORD_LAYER_reset_read_sequence(&s->rlayer);
793 }
794
795 if (!derive_secret_key_and_iv(s, sending, md,
796 s->s3.tmp.new_sym_enc, insecret, NULL,
797 application_traffic,
798 sizeof(application_traffic) - 1, secret, key,
799 iv, ciph_ctx)) {
800 /* SSLfatal() already called */
801 goto err;
802 }
803
804 memcpy(insecret, secret, hashlen);
805
806 /* Call Key log on successful traffic secret update */
807 log_label = s->server == sending ? SERVER_APPLICATION_N_LABEL : CLIENT_APPLICATION_N_LABEL;
808 if (!ssl_log_secret(s, log_label, secret, hashlen)) {
809 /* SSLfatal() already called */
810 goto err;
811 }
812
813 s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
814 ret = 1;
815 err:
816 OPENSSL_cleanse(key, sizeof(key));
817 OPENSSL_cleanse(secret, sizeof(secret));
818 return ret;
819 }
820
tls13_alert_code(int code)821 int tls13_alert_code(int code)
822 {
823 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
824 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
825 return code;
826
827 return tls1_alert_code(code);
828 }
829
tls13_export_keying_material(SSL * s,unsigned char * out,size_t olen,const char * label,size_t llen,const unsigned char * context,size_t contextlen,int use_context)830 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
831 const char *label, size_t llen,
832 const unsigned char *context,
833 size_t contextlen, int use_context)
834 {
835 unsigned char exportsecret[EVP_MAX_MD_SIZE];
836 #ifdef CHARSET_EBCDIC
837 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
838 #else
839 static const unsigned char exporterlabel[] = "exporter";
840 #endif
841 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
842 const EVP_MD *md = ssl_handshake_md(s);
843 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
844 unsigned int hashsize, datalen;
845 int ret = 0;
846
847 if (ctx == NULL || md == NULL || !ossl_statem_export_allowed(s))
848 goto err;
849
850 if (!use_context)
851 contextlen = 0;
852
853 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
854 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
855 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
856 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
857 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
858 || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
859 (const unsigned char *)label, llen,
860 data, datalen, exportsecret, hashsize, 0)
861 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
862 sizeof(exporterlabel) - 1, hash, hashsize,
863 out, olen, 0))
864 goto err;
865
866 ret = 1;
867 err:
868 EVP_MD_CTX_free(ctx);
869 return ret;
870 }
871
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)872 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
873 const char *label, size_t llen,
874 const unsigned char *context,
875 size_t contextlen)
876 {
877 #ifdef CHARSET_EBCDIC
878 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
879 #else
880 static const unsigned char exporterlabel[] = "exporter";
881 #endif
882 unsigned char exportsecret[EVP_MAX_MD_SIZE];
883 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
884 const EVP_MD *md;
885 EVP_MD_CTX *ctx = EVP_MD_CTX_new();
886 unsigned int hashsize, datalen;
887 int ret = 0;
888 const SSL_CIPHER *sslcipher;
889
890 if (ctx == NULL || !ossl_statem_export_early_allowed(s))
891 goto err;
892
893 if (!s->server && s->max_early_data > 0
894 && s->session->ext.max_early_data == 0)
895 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
896 else
897 sslcipher = SSL_SESSION_get0_cipher(s->session);
898
899 md = ssl_md(s->ctx, sslcipher->algorithm2);
900
901 /*
902 * Calculate the hash value and store it in |data|. The reason why
903 * the empty string is used is that the definition of TLS-Exporter
904 * is like so:
905 *
906 * TLS-Exporter(label, context_value, key_length) =
907 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
908 * "exporter", Hash(context_value), key_length)
909 *
910 * Derive-Secret(Secret, Label, Messages) =
911 * HKDF-Expand-Label(Secret, Label,
912 * Transcript-Hash(Messages), Hash.length)
913 *
914 * Here Transcript-Hash is the cipher suite hash algorithm.
915 */
916 if (md == NULL
917 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
918 || EVP_DigestUpdate(ctx, context, contextlen) <= 0
919 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
920 || EVP_DigestInit_ex(ctx, md, NULL) <= 0
921 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
922 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
923 (const unsigned char *)label, llen,
924 data, datalen, exportsecret, hashsize, 0)
925 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
926 sizeof(exporterlabel) - 1, hash, hashsize,
927 out, olen, 0))
928 goto err;
929
930 ret = 1;
931 err:
932 EVP_MD_CTX_free(ctx);
933 return ret;
934 }
935