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1 | /* | |
2 | * Copyright 2016-2020 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/cryptlib.h" | |
13 | #include <openssl/evp.h> | |
14 | #include <openssl/kdf.h> | |
15 | #include <openssl/core_names.h> | |
16 | ||
17 | #define TLS13_MAX_LABEL_LEN 249 | |
18 | ||
19 | /* Always filled with zeros */ | |
20 | static const unsigned char default_zeros[EVP_MAX_MD_SIZE]; | |
21 | ||
22 | /* | |
23 | * Given a |secret|; a |label| of length |labellen|; and |data| of length | |
24 | * |datalen| (e.g. typically a hash of the handshake messages), derive a new | |
25 | * secret |outlen| bytes long and store it in the location pointed to be |out|. | |
26 | * The |data| value may be zero length. Any errors will be treated as fatal if | |
27 | * |fatal| is set. Returns 1 on success 0 on failure. | |
28 | */ | |
29 | int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, | |
30 | const unsigned char *label, size_t labellen, | |
31 | const unsigned char *data, size_t datalen, | |
32 | unsigned char *out, size_t outlen, int fatal) | |
33 | { | |
34 | #ifdef CHARSET_EBCDIC | |
35 | static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 }; | |
36 | #else | |
37 | static const unsigned char label_prefix[] = "tls13 "; | |
38 | #endif | |
39 | EVP_KDF *kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_HKDF, | |
40 | s->ctx->propq); | |
41 | EVP_KDF_CTX *kctx; | |
42 | OSSL_PARAM params[5], *p = params; | |
43 | int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY; | |
44 | const char *mdname = EVP_MD_name(md); | |
45 | int ret; | |
46 | size_t hkdflabellen; | |
47 | size_t hashlen; | |
48 | /* | |
49 | * 2 bytes for length of derived secret + 1 byte for length of combined | |
50 | * prefix and label + bytes for the label itself + 1 byte length of hash | |
51 | * + bytes for the hash itself | |
52 | */ | |
53 | unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) | |
54 | + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN | |
55 | + 1 + EVP_MAX_MD_SIZE]; | |
56 | WPACKET pkt; | |
57 | ||
58 | kctx = EVP_KDF_CTX_new(kdf); | |
59 | EVP_KDF_free(kdf); | |
60 | if (kctx == NULL) | |
61 | return 0; | |
62 | ||
63 | if (labellen > TLS13_MAX_LABEL_LEN) { | |
64 | if (fatal) { | |
65 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, | |
66 | ERR_R_INTERNAL_ERROR); | |
67 | } else { | |
68 | /* | |
69 | * Probably we have been called from SSL_export_keying_material(), | |
70 | * or SSL_export_keying_material_early(). | |
71 | */ | |
72 | SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL); | |
73 | } | |
74 | EVP_KDF_CTX_free(kctx); | |
75 | return 0; | |
76 | } | |
77 | ||
78 | hashlen = EVP_MD_size(md); | |
79 | ||
80 | if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0) | |
81 | || !WPACKET_put_bytes_u16(&pkt, outlen) | |
82 | || !WPACKET_start_sub_packet_u8(&pkt) | |
83 | || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1) | |
84 | || !WPACKET_memcpy(&pkt, label, labellen) | |
85 | || !WPACKET_close(&pkt) | |
86 | || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen) | |
87 | || !WPACKET_get_total_written(&pkt, &hkdflabellen) | |
88 | || !WPACKET_finish(&pkt)) { | |
89 | EVP_KDF_CTX_free(kctx); | |
90 | WPACKET_cleanup(&pkt); | |
91 | if (fatal) | |
92 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, | |
93 | ERR_R_INTERNAL_ERROR); | |
94 | else | |
95 | SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); | |
96 | return 0; | |
97 | } | |
98 | ||
99 | *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode); | |
100 | *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST, | |
101 | (char *)mdname, 0); | |
102 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY, | |
103 | (unsigned char *)secret, hashlen); | |
104 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_INFO, | |
105 | hkdflabel, hkdflabellen); | |
106 | *p++ = OSSL_PARAM_construct_end(); | |
107 | ||
108 | ret = EVP_KDF_CTX_set_params(kctx, params) <= 0 | |
109 | || EVP_KDF_derive(kctx, out, outlen) <= 0; | |
110 | ||
111 | EVP_KDF_CTX_free(kctx); | |
112 | ||
113 | if (ret != 0) { | |
114 | if (fatal) | |
115 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, | |
116 | ERR_R_INTERNAL_ERROR); | |
117 | else | |
118 | SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); | |
119 | } | |
120 | ||
121 | return ret == 0; | |
122 | } | |
123 | ||
124 | /* | |
125 | * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on | |
126 | * success 0 on failure. | |
127 | */ | |
128 | int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret, | |
129 | unsigned char *key, size_t keylen) | |
130 | { | |
131 | #ifdef CHARSET_EBCDIC | |
132 | static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 }; | |
133 | #else | |
134 | static const unsigned char keylabel[] = "key"; | |
135 | #endif | |
136 | ||
137 | return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1, | |
138 | NULL, 0, key, keylen, 1); | |
139 | } | |
140 | ||
141 | /* | |
142 | * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on | |
143 | * success 0 on failure. | |
144 | */ | |
145 | int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret, | |
146 | unsigned char *iv, size_t ivlen) | |
147 | { | |
148 | #ifdef CHARSET_EBCDIC | |
149 | static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 }; | |
150 | #else | |
151 | static const unsigned char ivlabel[] = "iv"; | |
152 | #endif | |
153 | ||
154 | return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1, | |
155 | NULL, 0, iv, ivlen, 1); | |
156 | } | |
157 | ||
158 | int tls13_derive_finishedkey(SSL *s, const EVP_MD *md, | |
159 | const unsigned char *secret, | |
160 | unsigned char *fin, size_t finlen) | |
161 | { | |
162 | #ifdef CHARSET_EBCDIC | |
163 | static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 }; | |
164 | #else | |
165 | static const unsigned char finishedlabel[] = "finished"; | |
166 | #endif | |
167 | ||
168 | return tls13_hkdf_expand(s, md, secret, finishedlabel, | |
169 | sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1); | |
170 | } | |
171 | ||
172 | /* | |
173 | * Given the previous secret |prevsecret| and a new input secret |insecret| of | |
174 | * length |insecretlen|, generate a new secret and store it in the location | |
175 | * pointed to by |outsecret|. Returns 1 on success 0 on failure. | |
176 | */ | |
177 | int tls13_generate_secret(SSL *s, const EVP_MD *md, | |
178 | const unsigned char *prevsecret, | |
179 | const unsigned char *insecret, | |
180 | size_t insecretlen, | |
181 | unsigned char *outsecret) | |
182 | { | |
183 | size_t mdlen, prevsecretlen; | |
184 | int mdleni; | |
185 | int ret; | |
186 | EVP_KDF *kdf; | |
187 | EVP_KDF_CTX *kctx; | |
188 | OSSL_PARAM params[5], *p = params; | |
189 | int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY; | |
190 | const char *mdname = EVP_MD_name(md); | |
191 | #ifdef CHARSET_EBCDIC | |
192 | static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 }; | |
193 | #else | |
194 | static const char derived_secret_label[] = "derived"; | |
195 | #endif | |
196 | unsigned char preextractsec[EVP_MAX_MD_SIZE]; | |
197 | ||
198 | kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_HKDF, s->ctx->propq); | |
199 | kctx = EVP_KDF_CTX_new(kdf); | |
200 | EVP_KDF_free(kdf); | |
201 | if (kctx == NULL) { | |
202 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, | |
203 | ERR_R_INTERNAL_ERROR); | |
204 | return 0; | |
205 | } | |
206 | ||
207 | mdleni = EVP_MD_size(md); | |
208 | /* Ensure cast to size_t is safe */ | |
209 | if (!ossl_assert(mdleni >= 0)) { | |
210 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, | |
211 | ERR_R_INTERNAL_ERROR); | |
212 | EVP_KDF_CTX_free(kctx); | |
213 | return 0; | |
214 | } | |
215 | mdlen = (size_t)mdleni; | |
216 | ||
217 | if (insecret == NULL) { | |
218 | insecret = default_zeros; | |
219 | insecretlen = mdlen; | |
220 | } | |
221 | if (prevsecret == NULL) { | |
222 | prevsecret = default_zeros; | |
223 | prevsecretlen = 0; | |
224 | } else { | |
225 | EVP_MD_CTX *mctx = EVP_MD_CTX_new(); | |
226 | unsigned char hash[EVP_MAX_MD_SIZE]; | |
227 | ||
228 | /* The pre-extract derive step uses a hash of no messages */ | |
229 | if (mctx == NULL | |
230 | || EVP_DigestInit_ex(mctx, md, NULL) <= 0 | |
231 | || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { | |
232 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, | |
233 | ERR_R_INTERNAL_ERROR); | |
234 | EVP_MD_CTX_free(mctx); | |
235 | EVP_KDF_CTX_free(kctx); | |
236 | return 0; | |
237 | } | |
238 | EVP_MD_CTX_free(mctx); | |
239 | ||
240 | /* Generate the pre-extract secret */ | |
241 | if (!tls13_hkdf_expand(s, md, prevsecret, | |
242 | (unsigned char *)derived_secret_label, | |
243 | sizeof(derived_secret_label) - 1, hash, mdlen, | |
244 | preextractsec, mdlen, 1)) { | |
245 | /* SSLfatal() already called */ | |
246 | EVP_KDF_CTX_free(kctx); | |
247 | return 0; | |
248 | } | |
249 | ||
250 | prevsecret = preextractsec; | |
251 | prevsecretlen = mdlen; | |
252 | } | |
253 | ||
254 | *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode); | |
255 | *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST, | |
256 | (char *)mdname, 0); | |
257 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY, | |
258 | (unsigned char *)insecret, | |
259 | insecretlen); | |
260 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT, | |
261 | (unsigned char *)prevsecret, | |
262 | prevsecretlen); | |
263 | *p++ = OSSL_PARAM_construct_end(); | |
264 | ||
265 | ret = EVP_KDF_CTX_set_params(kctx, params) <= 0 | |
266 | || EVP_KDF_derive(kctx, outsecret, mdlen) <= 0; | |
267 | ||
268 | if (ret != 0) | |
269 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, | |
270 | ERR_R_INTERNAL_ERROR); | |
271 | ||
272 | EVP_KDF_CTX_free(kctx); | |
273 | if (prevsecret == preextractsec) | |
274 | OPENSSL_cleanse(preextractsec, mdlen); | |
275 | return ret == 0; | |
276 | } | |
277 | ||
278 | /* | |
279 | * Given an input secret |insecret| of length |insecretlen| generate the | |
280 | * handshake secret. This requires the early secret to already have been | |
281 | * generated. Returns 1 on success 0 on failure. | |
282 | */ | |
283 | int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret, | |
284 | size_t insecretlen) | |
285 | { | |
286 | /* Calls SSLfatal() if required */ | |
287 | return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret, | |
288 | insecret, insecretlen, | |
289 | (unsigned char *)&s->handshake_secret); | |
290 | } | |
291 | ||
292 | /* | |
293 | * Given the handshake secret |prev| of length |prevlen| generate the master | |
294 | * secret and store its length in |*secret_size|. Returns 1 on success 0 on | |
295 | * failure. | |
296 | */ | |
297 | int tls13_generate_master_secret(SSL *s, unsigned char *out, | |
298 | unsigned char *prev, size_t prevlen, | |
299 | size_t *secret_size) | |
300 | { | |
301 | const EVP_MD *md = ssl_handshake_md(s); | |
302 | ||
303 | *secret_size = EVP_MD_size(md); | |
304 | /* Calls SSLfatal() if required */ | |
305 | return tls13_generate_secret(s, md, prev, NULL, 0, out); | |
306 | } | |
307 | ||
308 | /* | |
309 | * Generates the mac for the Finished message. Returns the length of the MAC or | |
310 | * 0 on error. | |
311 | */ | |
312 | size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen, | |
313 | unsigned char *out) | |
314 | { | |
315 | const char *mdname = EVP_MD_name(ssl_handshake_md(s)); | |
316 | EVP_MAC *hmac = EVP_MAC_fetch(s->ctx->libctx, "HMAC", s->ctx->propq); | |
317 | unsigned char hash[EVP_MAX_MD_SIZE]; | |
318 | unsigned char finsecret[EVP_MAX_MD_SIZE]; | |
319 | size_t hashlen, ret = 0; | |
320 | EVP_MAC_CTX *ctx = NULL; | |
321 | OSSL_PARAM params[4], *p = params; | |
322 | ||
323 | if (hmac == NULL) { | |
324 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC, | |
325 | ERR_R_INTERNAL_ERROR); | |
326 | goto err; | |
327 | } | |
328 | ||
329 | /* Safe to cast away const here since we're not "getting" any data */ | |
330 | *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_DIGEST, | |
331 | (char *)mdname, 0); | |
332 | if (s->ctx->propq != NULL) | |
333 | *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES, | |
334 | (char *)s->ctx->propq, | |
335 | 0); | |
336 | ||
337 | if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) { | |
338 | /* SSLfatal() already called */ | |
339 | goto err; | |
340 | } | |
341 | ||
342 | if (str == s->method->ssl3_enc->server_finished_label) { | |
343 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, | |
344 | s->server_finished_secret, | |
345 | hashlen); | |
346 | } else if (SSL_IS_FIRST_HANDSHAKE(s)) { | |
347 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, | |
348 | s->client_finished_secret, | |
349 | hashlen); | |
350 | } else { | |
351 | if (!tls13_derive_finishedkey(s, ssl_handshake_md(s), | |
352 | s->client_app_traffic_secret, | |
353 | finsecret, hashlen)) | |
354 | goto err; | |
355 | ||
356 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, finsecret, | |
357 | hashlen); | |
358 | } | |
359 | *p++ = OSSL_PARAM_construct_end(); | |
360 | ||
361 | ctx = EVP_MAC_CTX_new(hmac); | |
362 | if (ctx == NULL | |
363 | || !EVP_MAC_CTX_set_params(ctx, params) | |
364 | || !EVP_MAC_init(ctx) | |
365 | || !EVP_MAC_update(ctx, hash, hashlen) | |
366 | /* outsize as per sizeof(peer_finish_md) */ | |
367 | || !EVP_MAC_final(ctx, out, &hashlen, EVP_MAX_MD_SIZE * 2)) { | |
368 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC, | |
369 | ERR_R_INTERNAL_ERROR); | |
370 | goto err; | |
371 | } | |
372 | ||
373 | ret = hashlen; | |
374 | err: | |
375 | OPENSSL_cleanse(finsecret, sizeof(finsecret)); | |
376 | EVP_MAC_CTX_free(ctx); | |
377 | EVP_MAC_free(hmac); | |
378 | return ret; | |
379 | } | |
380 | ||
381 | /* | |
382 | * There isn't really a key block in TLSv1.3, but we still need this function | |
383 | * for initialising the cipher and hash. Returns 1 on success or 0 on failure. | |
384 | */ | |
385 | int tls13_setup_key_block(SSL *s) | |
386 | { | |
387 | const EVP_CIPHER *c; | |
388 | const EVP_MD *hash; | |
389 | ||
390 | s->session->cipher = s->s3.tmp.new_cipher; | |
391 | if (!ssl_cipher_get_evp(s->ctx, s->session, &c, &hash, NULL, NULL, NULL, | |
392 | 0)) { | |
393 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK, | |
394 | SSL_R_CIPHER_OR_HASH_UNAVAILABLE); | |
395 | return 0; | |
396 | } | |
397 | ||
398 | ssl_evp_cipher_free(s->s3.tmp.new_sym_enc); | |
399 | s->s3.tmp.new_sym_enc = c; | |
400 | ssl_evp_md_free(s->s3.tmp.new_hash); | |
401 | s->s3.tmp.new_hash = hash; | |
402 | ||
403 | return 1; | |
404 | } | |
405 | ||
406 | static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md, | |
407 | const EVP_CIPHER *ciph, | |
408 | const unsigned char *insecret, | |
409 | const unsigned char *hash, | |
410 | const unsigned char *label, | |
411 | size_t labellen, unsigned char *secret, | |
412 | unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx) | |
413 | { | |
414 | unsigned char key[EVP_MAX_KEY_LENGTH]; | |
415 | size_t ivlen, keylen, taglen; | |
416 | int hashleni = EVP_MD_size(md); | |
417 | size_t hashlen; | |
418 | ||
419 | /* Ensure cast to size_t is safe */ | |
420 | if (!ossl_assert(hashleni >= 0)) { | |
421 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, | |
422 | ERR_R_EVP_LIB); | |
423 | goto err; | |
424 | } | |
425 | hashlen = (size_t)hashleni; | |
426 | ||
427 | if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen, | |
428 | secret, hashlen, 1)) { | |
429 | /* SSLfatal() already called */ | |
430 | goto err; | |
431 | } | |
432 | ||
433 | /* TODO(size_t): convert me */ | |
434 | keylen = EVP_CIPHER_key_length(ciph); | |
435 | if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) { | |
436 | uint32_t algenc; | |
437 | ||
438 | ivlen = EVP_CCM_TLS_IV_LEN; | |
439 | if (s->s3.tmp.new_cipher == NULL) { | |
440 | /* We've not selected a cipher yet - we must be doing early data */ | |
441 | algenc = s->session->cipher->algorithm_enc; | |
442 | } else { | |
443 | algenc = s->s3.tmp.new_cipher->algorithm_enc; | |
444 | } | |
445 | if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8)) | |
446 | taglen = EVP_CCM8_TLS_TAG_LEN; | |
447 | else | |
448 | taglen = EVP_CCM_TLS_TAG_LEN; | |
449 | } else { | |
450 | ivlen = EVP_CIPHER_iv_length(ciph); | |
451 | taglen = 0; | |
452 | } | |
453 | ||
454 | if (!tls13_derive_key(s, md, secret, key, keylen) | |
455 | || !tls13_derive_iv(s, md, secret, iv, ivlen)) { | |
456 | /* SSLfatal() already called */ | |
457 | goto err; | |
458 | } | |
459 | ||
460 | if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0 | |
461 | || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) | |
462 | || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, | |
463 | taglen, NULL)) | |
464 | || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) { | |
465 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, | |
466 | ERR_R_EVP_LIB); | |
467 | goto err; | |
468 | } | |
469 | ||
470 | return 1; | |
471 | err: | |
472 | OPENSSL_cleanse(key, sizeof(key)); | |
473 | return 0; | |
474 | } | |
475 | ||
476 | int tls13_change_cipher_state(SSL *s, int which) | |
477 | { | |
478 | #ifdef CHARSET_EBCDIC | |
479 | static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; | |
480 | static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; | |
481 | static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; | |
482 | static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; | |
483 | static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; | |
484 | static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; | |
485 | static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; | |
486 | static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; | |
487 | #else | |
488 | static const unsigned char client_early_traffic[] = "c e traffic"; | |
489 | static const unsigned char client_handshake_traffic[] = "c hs traffic"; | |
490 | static const unsigned char client_application_traffic[] = "c ap traffic"; | |
491 | static const unsigned char server_handshake_traffic[] = "s hs traffic"; | |
492 | static const unsigned char server_application_traffic[] = "s ap traffic"; | |
493 | static const unsigned char exporter_master_secret[] = "exp master"; | |
494 | static const unsigned char resumption_master_secret[] = "res master"; | |
495 | static const unsigned char early_exporter_master_secret[] = "e exp master"; | |
496 | #endif | |
497 | unsigned char *iv; | |
498 | unsigned char secret[EVP_MAX_MD_SIZE]; | |
499 | unsigned char hashval[EVP_MAX_MD_SIZE]; | |
500 | unsigned char *hash = hashval; | |
501 | unsigned char *insecret; | |
502 | unsigned char *finsecret = NULL; | |
503 | const char *log_label = NULL; | |
504 | EVP_CIPHER_CTX *ciph_ctx; | |
505 | size_t finsecretlen = 0; | |
506 | const unsigned char *label; | |
507 | size_t labellen, hashlen = 0; | |
508 | int ret = 0; | |
509 | const EVP_MD *md = NULL; | |
510 | const EVP_CIPHER *cipher = NULL; | |
511 | ||
512 | if (which & SSL3_CC_READ) { | |
513 | if (s->enc_read_ctx != NULL) { | |
514 | EVP_CIPHER_CTX_reset(s->enc_read_ctx); | |
515 | } else { | |
516 | s->enc_read_ctx = EVP_CIPHER_CTX_new(); | |
517 | if (s->enc_read_ctx == NULL) { | |
518 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, | |
519 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); | |
520 | goto err; | |
521 | } | |
522 | } | |
523 | ciph_ctx = s->enc_read_ctx; | |
524 | iv = s->read_iv; | |
525 | ||
526 | RECORD_LAYER_reset_read_sequence(&s->rlayer); | |
527 | } else { | |
528 | s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; | |
529 | if (s->enc_write_ctx != NULL) { | |
530 | EVP_CIPHER_CTX_reset(s->enc_write_ctx); | |
531 | } else { | |
532 | s->enc_write_ctx = EVP_CIPHER_CTX_new(); | |
533 | if (s->enc_write_ctx == NULL) { | |
534 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, | |
535 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); | |
536 | goto err; | |
537 | } | |
538 | } | |
539 | ciph_ctx = s->enc_write_ctx; | |
540 | iv = s->write_iv; | |
541 | ||
542 | RECORD_LAYER_reset_write_sequence(&s->rlayer); | |
543 | } | |
544 | ||
545 | if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE)) | |
546 | || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) { | |
547 | if (which & SSL3_CC_EARLY) { | |
548 | EVP_MD_CTX *mdctx = NULL; | |
549 | long handlen; | |
550 | void *hdata; | |
551 | unsigned int hashlenui; | |
552 | const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session); | |
553 | ||
554 | insecret = s->early_secret; | |
555 | label = client_early_traffic; | |
556 | labellen = sizeof(client_early_traffic) - 1; | |
557 | log_label = CLIENT_EARLY_LABEL; | |
558 | ||
559 | handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata); | |
560 | if (handlen <= 0) { | |
561 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, | |
562 | SSL_F_TLS13_CHANGE_CIPHER_STATE, | |
563 | SSL_R_BAD_HANDSHAKE_LENGTH); | |
564 | goto err; | |
565 | } | |
566 | ||
567 | if (s->early_data_state == SSL_EARLY_DATA_CONNECTING | |
568 | && s->max_early_data > 0 | |
569 | && s->session->ext.max_early_data == 0) { | |
570 | /* | |
571 | * If we are attempting to send early data, and we've decided to | |
572 | * actually do it but max_early_data in s->session is 0 then we | |
573 | * must be using an external PSK. | |
574 | */ | |
575 | if (!ossl_assert(s->psksession != NULL | |
576 | && s->max_early_data == | |
577 | s->psksession->ext.max_early_data)) { | |
578 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, | |
579 | SSL_F_TLS13_CHANGE_CIPHER_STATE, | |
580 | ERR_R_INTERNAL_ERROR); | |
581 | goto err; | |
582 | } | |
583 | sslcipher = SSL_SESSION_get0_cipher(s->psksession); | |
584 | } | |
585 | if (sslcipher == NULL) { | |
586 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, | |
587 | SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK); | |
588 | goto err; | |
589 | } | |
590 | ||
591 | /* | |
592 | * We need to calculate the handshake digest using the digest from | |
593 | * the session. We haven't yet selected our ciphersuite so we can't | |
594 | * use ssl_handshake_md(). | |
595 | */ | |
596 | mdctx = EVP_MD_CTX_new(); | |
597 | if (mdctx == NULL) { | |
598 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, | |
599 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); | |
600 | goto err; | |
601 | } | |
602 | ||
603 | /* | |
604 | * This ups the ref count on cipher so we better make sure we free | |
605 | * it again | |
606 | */ | |
607 | if (!ssl_cipher_get_evp_cipher(s->ctx, sslcipher, &cipher)) { | |
608 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, | |
609 | SSL_F_TLS13_CHANGE_CIPHER_STATE, | |
610 | SSL_R_ALGORITHM_FETCH_FAILED); | |
611 | EVP_MD_CTX_free(mdctx); | |
612 | goto err; | |
613 | } | |
614 | ||
615 | md = ssl_md(s->ctx, sslcipher->algorithm2); | |
616 | if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL) | |
617 | || !EVP_DigestUpdate(mdctx, hdata, handlen) | |
618 | || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) { | |
619 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, | |
620 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); | |
621 | EVP_MD_CTX_free(mdctx); | |
622 | goto err; | |
623 | } | |
624 | hashlen = hashlenui; | |
625 | EVP_MD_CTX_free(mdctx); | |
626 | ||
627 | if (!tls13_hkdf_expand(s, md, insecret, | |
628 | early_exporter_master_secret, | |
629 | sizeof(early_exporter_master_secret) - 1, | |
630 | hashval, hashlen, | |
631 | s->early_exporter_master_secret, hashlen, | |
632 | 1)) { | |
633 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, | |
634 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); | |
635 | goto err; | |
636 | } | |
637 | ||
638 | if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL, | |
639 | s->early_exporter_master_secret, hashlen)) { | |
640 | /* SSLfatal() already called */ | |
641 | goto err; | |
642 | } | |
643 | } else if (which & SSL3_CC_HANDSHAKE) { | |
644 | insecret = s->handshake_secret; | |
645 | finsecret = s->client_finished_secret; | |
646 | finsecretlen = EVP_MD_size(ssl_handshake_md(s)); | |
647 | label = client_handshake_traffic; | |
648 | labellen = sizeof(client_handshake_traffic) - 1; | |
649 | log_label = CLIENT_HANDSHAKE_LABEL; | |
650 | /* | |
651 | * The handshake hash used for the server read/client write handshake | |
652 | * traffic secret is the same as the hash for the server | |
653 | * write/client read handshake traffic secret. However, if we | |
654 | * processed early data then we delay changing the server | |
655 | * read/client write cipher state until later, and the handshake | |
656 | * hashes have moved on. Therefore we use the value saved earlier | |
657 | * when we did the server write/client read change cipher state. | |
658 | */ | |
659 | hash = s->handshake_traffic_hash; | |
660 | } else { | |
661 | insecret = s->master_secret; | |
662 | label = client_application_traffic; | |
663 | labellen = sizeof(client_application_traffic) - 1; | |
664 | log_label = CLIENT_APPLICATION_LABEL; | |
665 | /* | |
666 | * For this we only use the handshake hashes up until the server | |
667 | * Finished hash. We do not include the client's Finished, which is | |
668 | * what ssl_handshake_hash() would give us. Instead we use the | |
669 | * previously saved value. | |
670 | */ | |
671 | hash = s->server_finished_hash; | |
672 | } | |
673 | } else { | |
674 | /* Early data never applies to client-read/server-write */ | |
675 | if (which & SSL3_CC_HANDSHAKE) { | |
676 | insecret = s->handshake_secret; | |
677 | finsecret = s->server_finished_secret; | |
678 | finsecretlen = EVP_MD_size(ssl_handshake_md(s)); | |
679 | label = server_handshake_traffic; | |
680 | labellen = sizeof(server_handshake_traffic) - 1; | |
681 | log_label = SERVER_HANDSHAKE_LABEL; | |
682 | } else { | |
683 | insecret = s->master_secret; | |
684 | label = server_application_traffic; | |
685 | labellen = sizeof(server_application_traffic) - 1; | |
686 | log_label = SERVER_APPLICATION_LABEL; | |
687 | } | |
688 | } | |
689 | ||
690 | if (!(which & SSL3_CC_EARLY)) { | |
691 | md = ssl_handshake_md(s); | |
692 | cipher = s->s3.tmp.new_sym_enc; | |
693 | if (!ssl3_digest_cached_records(s, 1) | |
694 | || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) { | |
695 | /* SSLfatal() already called */; | |
696 | goto err; | |
697 | } | |
698 | } | |
699 | ||
700 | /* | |
701 | * Save the hash of handshakes up to now for use when we calculate the | |
702 | * client application traffic secret | |
703 | */ | |
704 | if (label == server_application_traffic) | |
705 | memcpy(s->server_finished_hash, hashval, hashlen); | |
706 | ||
707 | if (label == server_handshake_traffic) | |
708 | memcpy(s->handshake_traffic_hash, hashval, hashlen); | |
709 | ||
710 | if (label == client_application_traffic) { | |
711 | /* | |
712 | * We also create the resumption master secret, but this time use the | |
713 | * hash for the whole handshake including the Client Finished | |
714 | */ | |
715 | if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, | |
716 | resumption_master_secret, | |
717 | sizeof(resumption_master_secret) - 1, | |
718 | hashval, hashlen, s->resumption_master_secret, | |
719 | hashlen, 1)) { | |
720 | /* SSLfatal() already called */ | |
721 | goto err; | |
722 | } | |
723 | } | |
724 | ||
725 | if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, | |
726 | insecret, hash, label, labellen, secret, iv, | |
727 | ciph_ctx)) { | |
728 | /* SSLfatal() already called */ | |
729 | goto err; | |
730 | } | |
731 | ||
732 | if (label == server_application_traffic) { | |
733 | memcpy(s->server_app_traffic_secret, secret, hashlen); | |
734 | /* Now we create the exporter master secret */ | |
735 | if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, | |
736 | exporter_master_secret, | |
737 | sizeof(exporter_master_secret) - 1, | |
738 | hash, hashlen, s->exporter_master_secret, | |
739 | hashlen, 1)) { | |
740 | /* SSLfatal() already called */ | |
741 | goto err; | |
742 | } | |
743 | ||
744 | if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret, | |
745 | hashlen)) { | |
746 | /* SSLfatal() already called */ | |
747 | goto err; | |
748 | } | |
749 | } else if (label == client_application_traffic) | |
750 | memcpy(s->client_app_traffic_secret, secret, hashlen); | |
751 | ||
752 | if (!ssl_log_secret(s, log_label, secret, hashlen)) { | |
753 | /* SSLfatal() already called */ | |
754 | goto err; | |
755 | } | |
756 | ||
757 | if (finsecret != NULL | |
758 | && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret, | |
759 | finsecret, finsecretlen)) { | |
760 | /* SSLfatal() already called */ | |
761 | goto err; | |
762 | } | |
763 | ||
764 | if (!s->server && label == client_early_traffic) | |
765 | s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS; | |
766 | else | |
767 | s->statem.enc_write_state = ENC_WRITE_STATE_VALID; | |
768 | ret = 1; | |
769 | err: | |
770 | if ((which & SSL3_CC_EARLY) != 0) { | |
771 | /* We up-refed this so now we need to down ref */ | |
772 | ssl_evp_cipher_free(cipher); | |
773 | } | |
774 | OPENSSL_cleanse(secret, sizeof(secret)); | |
775 | return ret; | |
776 | } | |
777 | ||
778 | int tls13_update_key(SSL *s, int sending) | |
779 | { | |
780 | #ifdef CHARSET_EBCDIC | |
781 | static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00}; | |
782 | #else | |
783 | static const unsigned char application_traffic[] = "traffic upd"; | |
784 | #endif | |
785 | const EVP_MD *md = ssl_handshake_md(s); | |
786 | size_t hashlen = EVP_MD_size(md); | |
787 | unsigned char *insecret, *iv; | |
788 | unsigned char secret[EVP_MAX_MD_SIZE]; | |
789 | EVP_CIPHER_CTX *ciph_ctx; | |
790 | int ret = 0; | |
791 | ||
792 | if (s->server == sending) | |
793 | insecret = s->server_app_traffic_secret; | |
794 | else | |
795 | insecret = s->client_app_traffic_secret; | |
796 | ||
797 | if (sending) { | |
798 | s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; | |
799 | iv = s->write_iv; | |
800 | ciph_ctx = s->enc_write_ctx; | |
801 | RECORD_LAYER_reset_write_sequence(&s->rlayer); | |
802 | } else { | |
803 | iv = s->read_iv; | |
804 | ciph_ctx = s->enc_read_ctx; | |
805 | RECORD_LAYER_reset_read_sequence(&s->rlayer); | |
806 | } | |
807 | ||
808 | if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s), | |
809 | s->s3.tmp.new_sym_enc, insecret, NULL, | |
810 | application_traffic, | |
811 | sizeof(application_traffic) - 1, secret, iv, | |
812 | ciph_ctx)) { | |
813 | /* SSLfatal() already called */ | |
814 | goto err; | |
815 | } | |
816 | ||
817 | memcpy(insecret, secret, hashlen); | |
818 | ||
819 | s->statem.enc_write_state = ENC_WRITE_STATE_VALID; | |
820 | ret = 1; | |
821 | err: | |
822 | OPENSSL_cleanse(secret, sizeof(secret)); | |
823 | return ret; | |
824 | } | |
825 | ||
826 | int tls13_alert_code(int code) | |
827 | { | |
828 | /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */ | |
829 | if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED) | |
830 | return code; | |
831 | ||
832 | return tls1_alert_code(code); | |
833 | } | |
834 | ||
835 | int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, | |
836 | const char *label, size_t llen, | |
837 | const unsigned char *context, | |
838 | size_t contextlen, int use_context) | |
839 | { | |
840 | unsigned char exportsecret[EVP_MAX_MD_SIZE]; | |
841 | #ifdef CHARSET_EBCDIC | |
842 | static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; | |
843 | #else | |
844 | static const unsigned char exporterlabel[] = "exporter"; | |
845 | #endif | |
846 | unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; | |
847 | const EVP_MD *md = ssl_handshake_md(s); | |
848 | EVP_MD_CTX *ctx = EVP_MD_CTX_new(); | |
849 | unsigned int hashsize, datalen; | |
850 | int ret = 0; | |
851 | ||
852 | if (ctx == NULL || !ossl_statem_export_allowed(s)) | |
853 | goto err; | |
854 | ||
855 | if (!use_context) | |
856 | contextlen = 0; | |
857 | ||
858 | if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 | |
859 | || EVP_DigestUpdate(ctx, context, contextlen) <= 0 | |
860 | || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 | |
861 | || EVP_DigestInit_ex(ctx, md, NULL) <= 0 | |
862 | || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 | |
863 | || !tls13_hkdf_expand(s, md, s->exporter_master_secret, | |
864 | (const unsigned char *)label, llen, | |
865 | data, datalen, exportsecret, hashsize, 0) | |
866 | || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, | |
867 | sizeof(exporterlabel) - 1, hash, hashsize, | |
868 | out, olen, 0)) | |
869 | goto err; | |
870 | ||
871 | ret = 1; | |
872 | err: | |
873 | EVP_MD_CTX_free(ctx); | |
874 | return ret; | |
875 | } | |
876 | ||
877 | int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, | |
878 | const char *label, size_t llen, | |
879 | const unsigned char *context, | |
880 | size_t contextlen) | |
881 | { | |
882 | #ifdef CHARSET_EBCDIC | |
883 | static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; | |
884 | #else | |
885 | static const unsigned char exporterlabel[] = "exporter"; | |
886 | #endif | |
887 | unsigned char exportsecret[EVP_MAX_MD_SIZE]; | |
888 | unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; | |
889 | const EVP_MD *md; | |
890 | EVP_MD_CTX *ctx = EVP_MD_CTX_new(); | |
891 | unsigned int hashsize, datalen; | |
892 | int ret = 0; | |
893 | const SSL_CIPHER *sslcipher; | |
894 | ||
895 | if (ctx == NULL || !ossl_statem_export_early_allowed(s)) | |
896 | goto err; | |
897 | ||
898 | if (!s->server && s->max_early_data > 0 | |
899 | && s->session->ext.max_early_data == 0) | |
900 | sslcipher = SSL_SESSION_get0_cipher(s->psksession); | |
901 | else | |
902 | sslcipher = SSL_SESSION_get0_cipher(s->session); | |
903 | ||
904 | md = ssl_md(s->ctx, sslcipher->algorithm2); | |
905 | ||
906 | /* | |
907 | * Calculate the hash value and store it in |data|. The reason why | |
908 | * the empty string is used is that the definition of TLS-Exporter | |
909 | * is like so: | |
910 | * | |
911 | * TLS-Exporter(label, context_value, key_length) = | |
912 | * HKDF-Expand-Label(Derive-Secret(Secret, label, ""), | |
913 | * "exporter", Hash(context_value), key_length) | |
914 | * | |
915 | * Derive-Secret(Secret, Label, Messages) = | |
916 | * HKDF-Expand-Label(Secret, Label, | |
917 | * Transcript-Hash(Messages), Hash.length) | |
918 | * | |
919 | * Here Transcript-Hash is the cipher suite hash algorithm. | |
920 | */ | |
921 | if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 | |
922 | || EVP_DigestUpdate(ctx, context, contextlen) <= 0 | |
923 | || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 | |
924 | || EVP_DigestInit_ex(ctx, md, NULL) <= 0 | |
925 | || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 | |
926 | || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret, | |
927 | (const unsigned char *)label, llen, | |
928 | data, datalen, exportsecret, hashsize, 0) | |
929 | || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, | |
930 | sizeof(exporterlabel) - 1, hash, hashsize, | |
931 | out, olen, 0)) | |
932 | goto err; | |
933 | ||
934 | ret = 1; | |
935 | err: | |
936 | EVP_MD_CTX_free(ctx); | |
937 | return ret; | |
938 | } |