1 | /* |
2 | * Copyright 2016-2018 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(NULL, OSSL_KDF_NAME_HKDF, NULL); |
40 | EVP_KDF_CTX *kctx; |
41 | OSSL_PARAM params[5], *p = params; |
42 | int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY; |
43 | const char *mdname = EVP_MD_name(md); |
44 | int ret; |
45 | size_t hkdflabellen; |
46 | size_t hashlen; |
47 | /* |
48 | * 2 bytes for length of derived secret + 1 byte for length of combined |
49 | * prefix and label + bytes for the label itself + 1 byte length of hash |
50 | * + bytes for the hash itself |
51 | */ |
52 | unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) + |
53 | + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN |
54 | + 1 + EVP_MAX_MD_SIZE]; |
55 | WPACKET pkt; |
56 | |
57 | kctx = EVP_KDF_CTX_new(kdf); |
58 | EVP_KDF_free(kdf); |
59 | if (kctx == NULL) |
60 | return 0; |
61 | |
62 | if (labellen > TLS13_MAX_LABEL_LEN) { |
63 | if (fatal) { |
64 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, |
65 | ERR_R_INTERNAL_ERROR); |
66 | } else { |
67 | /* |
68 | * Probably we have been called from SSL_export_keying_material(), |
69 | * or SSL_export_keying_material_early(). |
70 | */ |
71 | SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL); |
72 | } |
73 | EVP_KDF_CTX_free(kctx); |
74 | return 0; |
75 | } |
76 | |
77 | hashlen = EVP_MD_size(md); |
78 | |
79 | if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0) |
80 | || !WPACKET_put_bytes_u16(&pkt, outlen) |
81 | || !WPACKET_start_sub_packet_u8(&pkt) |
82 | || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1) |
83 | || !WPACKET_memcpy(&pkt, label, labellen) |
84 | || !WPACKET_close(&pkt) |
85 | || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen) |
86 | || !WPACKET_get_total_written(&pkt, &hkdflabellen) |
87 | || !WPACKET_finish(&pkt)) { |
88 | EVP_KDF_CTX_free(kctx); |
89 | WPACKET_cleanup(&pkt); |
90 | if (fatal) |
91 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, |
92 | ERR_R_INTERNAL_ERROR); |
93 | else |
94 | SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); |
95 | return 0; |
96 | } |
97 | |
98 | *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode); |
99 | *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST, |
100 | (char *)mdname, strlen(mdname) + 1); |
101 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY, |
102 | (unsigned char *)secret, hashlen); |
103 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_INFO, |
104 | hkdflabel, hkdflabellen); |
105 | *p++ = OSSL_PARAM_construct_end(); |
106 | |
107 | ret = EVP_KDF_CTX_set_params(kctx, params) <= 0 |
108 | || EVP_KDF_derive(kctx, out, outlen) <= 0; |
109 | |
110 | EVP_KDF_CTX_free(kctx); |
111 | |
112 | if (ret != 0) { |
113 | if (fatal) |
114 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, |
115 | ERR_R_INTERNAL_ERROR); |
116 | else |
117 | SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); |
118 | } |
119 | |
120 | return ret == 0; |
121 | } |
122 | |
123 | /* |
124 | * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on |
125 | * success 0 on failure. |
126 | */ |
127 | int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret, |
128 | unsigned char *key, size_t keylen) |
129 | { |
130 | #ifdef CHARSET_EBCDIC |
131 | static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 }; |
132 | #else |
133 | static const unsigned char keylabel[] = "key" ; |
134 | #endif |
135 | |
136 | return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1, |
137 | NULL, 0, key, keylen, 1); |
138 | } |
139 | |
140 | /* |
141 | * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on |
142 | * success 0 on failure. |
143 | */ |
144 | int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret, |
145 | unsigned char *iv, size_t ivlen) |
146 | { |
147 | #ifdef CHARSET_EBCDIC |
148 | static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 }; |
149 | #else |
150 | static const unsigned char ivlabel[] = "iv" ; |
151 | #endif |
152 | |
153 | return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1, |
154 | NULL, 0, iv, ivlen, 1); |
155 | } |
156 | |
157 | int tls13_derive_finishedkey(SSL *s, const EVP_MD *md, |
158 | const unsigned char *secret, |
159 | unsigned char *fin, size_t finlen) |
160 | { |
161 | #ifdef CHARSET_EBCDIC |
162 | static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 }; |
163 | #else |
164 | static const unsigned char finishedlabel[] = "finished" ; |
165 | #endif |
166 | |
167 | return tls13_hkdf_expand(s, md, secret, finishedlabel, |
168 | sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1); |
169 | } |
170 | |
171 | /* |
172 | * Given the previous secret |prevsecret| and a new input secret |insecret| of |
173 | * length |insecretlen|, generate a new secret and store it in the location |
174 | * pointed to by |outsecret|. Returns 1 on success 0 on failure. |
175 | */ |
176 | int tls13_generate_secret(SSL *s, const EVP_MD *md, |
177 | const unsigned char *prevsecret, |
178 | const unsigned char *insecret, |
179 | size_t insecretlen, |
180 | unsigned char *outsecret) |
181 | { |
182 | size_t mdlen, prevsecretlen; |
183 | int mdleni; |
184 | int ret; |
185 | EVP_KDF *kdf; |
186 | EVP_KDF_CTX *kctx; |
187 | OSSL_PARAM params[5], *p = params; |
188 | int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY; |
189 | const char *mdname = EVP_MD_name(md); |
190 | #ifdef CHARSET_EBCDIC |
191 | static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 }; |
192 | #else |
193 | static const char derived_secret_label[] = "derived" ; |
194 | #endif |
195 | unsigned char [EVP_MAX_MD_SIZE]; |
196 | |
197 | kdf = EVP_KDF_fetch(NULL, OSSL_KDF_NAME_HKDF, NULL); |
198 | kctx = EVP_KDF_CTX_new(kdf); |
199 | EVP_KDF_free(kdf); |
200 | if (kctx == NULL) { |
201 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, |
202 | ERR_R_INTERNAL_ERROR); |
203 | return 0; |
204 | } |
205 | |
206 | mdleni = EVP_MD_size(md); |
207 | /* Ensure cast to size_t is safe */ |
208 | if (!ossl_assert(mdleni >= 0)) { |
209 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, |
210 | ERR_R_INTERNAL_ERROR); |
211 | EVP_KDF_CTX_free(kctx); |
212 | return 0; |
213 | } |
214 | mdlen = (size_t)mdleni; |
215 | |
216 | if (insecret == NULL) { |
217 | insecret = default_zeros; |
218 | insecretlen = mdlen; |
219 | } |
220 | if (prevsecret == NULL) { |
221 | prevsecret = default_zeros; |
222 | prevsecretlen = 0; |
223 | } else { |
224 | EVP_MD_CTX *mctx = EVP_MD_CTX_new(); |
225 | unsigned char hash[EVP_MAX_MD_SIZE]; |
226 | |
227 | /* The pre-extract derive step uses a hash of no messages */ |
228 | if (mctx == NULL |
229 | || EVP_DigestInit_ex(mctx, md, NULL) <= 0 |
230 | || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { |
231 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, |
232 | ERR_R_INTERNAL_ERROR); |
233 | EVP_MD_CTX_free(mctx); |
234 | EVP_KDF_CTX_free(kctx); |
235 | return 0; |
236 | } |
237 | EVP_MD_CTX_free(mctx); |
238 | |
239 | /* Generate the pre-extract secret */ |
240 | if (!tls13_hkdf_expand(s, md, prevsecret, |
241 | (unsigned char *)derived_secret_label, |
242 | sizeof(derived_secret_label) - 1, hash, mdlen, |
243 | preextractsec, mdlen, 1)) { |
244 | /* SSLfatal() already called */ |
245 | EVP_KDF_CTX_free(kctx); |
246 | return 0; |
247 | } |
248 | |
249 | prevsecret = preextractsec; |
250 | prevsecretlen = mdlen; |
251 | } |
252 | |
253 | *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode); |
254 | *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST, |
255 | (char *)mdname, strlen(mdname) + 1); |
256 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY, |
257 | (unsigned char *)insecret, |
258 | insecretlen); |
259 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT, |
260 | (unsigned char *)prevsecret, |
261 | prevsecretlen); |
262 | *p++ = OSSL_PARAM_construct_end(); |
263 | |
264 | ret = EVP_KDF_CTX_set_params(kctx, params) <= 0 |
265 | || EVP_KDF_derive(kctx, outsecret, mdlen) <= 0; |
266 | |
267 | if (ret != 0) |
268 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, |
269 | ERR_R_INTERNAL_ERROR); |
270 | |
271 | EVP_KDF_CTX_free(kctx); |
272 | if (prevsecret == preextractsec) |
273 | OPENSSL_cleanse(preextractsec, mdlen); |
274 | return ret == 0; |
275 | } |
276 | |
277 | /* |
278 | * Given an input secret |insecret| of length |insecretlen| generate the |
279 | * handshake secret. This requires the early secret to already have been |
280 | * generated. Returns 1 on success 0 on failure. |
281 | */ |
282 | int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret, |
283 | size_t insecretlen) |
284 | { |
285 | /* Calls SSLfatal() if required */ |
286 | return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret, |
287 | insecret, insecretlen, |
288 | (unsigned char *)&s->handshake_secret); |
289 | } |
290 | |
291 | /* |
292 | * Given the handshake secret |prev| of length |prevlen| generate the master |
293 | * secret and store its length in |*secret_size|. Returns 1 on success 0 on |
294 | * failure. |
295 | */ |
296 | int tls13_generate_master_secret(SSL *s, unsigned char *out, |
297 | unsigned char *prev, size_t prevlen, |
298 | size_t *secret_size) |
299 | { |
300 | const EVP_MD *md = ssl_handshake_md(s); |
301 | |
302 | *secret_size = EVP_MD_size(md); |
303 | /* Calls SSLfatal() if required */ |
304 | return tls13_generate_secret(s, md, prev, NULL, 0, out); |
305 | } |
306 | |
307 | /* |
308 | * Generates the mac for the Finished message. Returns the length of the MAC or |
309 | * 0 on error. |
310 | */ |
311 | size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen, |
312 | unsigned char *out) |
313 | { |
314 | const EVP_MD *md = ssl_handshake_md(s); |
315 | unsigned char hash[EVP_MAX_MD_SIZE]; |
316 | size_t hashlen, ret = 0; |
317 | EVP_PKEY *key = NULL; |
318 | EVP_MD_CTX *ctx = EVP_MD_CTX_new(); |
319 | |
320 | if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) { |
321 | /* SSLfatal() already called */ |
322 | goto err; |
323 | } |
324 | |
325 | if (str == s->method->ssl3_enc->server_finished_label) { |
326 | key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, |
327 | s->server_finished_secret, hashlen); |
328 | } else if (SSL_IS_FIRST_HANDSHAKE(s)) { |
329 | key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, |
330 | s->client_finished_secret, hashlen); |
331 | } else { |
332 | unsigned char finsecret[EVP_MAX_MD_SIZE]; |
333 | |
334 | if (!tls13_derive_finishedkey(s, ssl_handshake_md(s), |
335 | s->client_app_traffic_secret, |
336 | finsecret, hashlen)) |
337 | goto err; |
338 | |
339 | key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret, |
340 | hashlen); |
341 | OPENSSL_cleanse(finsecret, sizeof(finsecret)); |
342 | } |
343 | |
344 | if (key == NULL |
345 | || ctx == NULL |
346 | || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0 |
347 | || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0 |
348 | || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) { |
349 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC, |
350 | ERR_R_INTERNAL_ERROR); |
351 | goto err; |
352 | } |
353 | |
354 | ret = hashlen; |
355 | err: |
356 | EVP_PKEY_free(key); |
357 | EVP_MD_CTX_free(ctx); |
358 | return ret; |
359 | } |
360 | |
361 | /* |
362 | * There isn't really a key block in TLSv1.3, but we still need this function |
363 | * for initialising the cipher and hash. Returns 1 on success or 0 on failure. |
364 | */ |
365 | int tls13_setup_key_block(SSL *s) |
366 | { |
367 | const EVP_CIPHER *c; |
368 | const EVP_MD *hash; |
369 | |
370 | s->session->cipher = s->s3.tmp.new_cipher; |
371 | if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) { |
372 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK, |
373 | SSL_R_CIPHER_OR_HASH_UNAVAILABLE); |
374 | return 0; |
375 | } |
376 | |
377 | s->s3.tmp.new_sym_enc = c; |
378 | s->s3.tmp.new_hash = hash; |
379 | |
380 | return 1; |
381 | } |
382 | |
383 | static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md, |
384 | const EVP_CIPHER *ciph, |
385 | const unsigned char *insecret, |
386 | const unsigned char *hash, |
387 | const unsigned char *label, |
388 | size_t labellen, unsigned char *secret, |
389 | unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx) |
390 | { |
391 | unsigned char key[EVP_MAX_KEY_LENGTH]; |
392 | size_t ivlen, keylen, taglen; |
393 | int hashleni = EVP_MD_size(md); |
394 | size_t hashlen; |
395 | |
396 | /* Ensure cast to size_t is safe */ |
397 | if (!ossl_assert(hashleni >= 0)) { |
398 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, |
399 | ERR_R_EVP_LIB); |
400 | goto err; |
401 | } |
402 | hashlen = (size_t)hashleni; |
403 | |
404 | if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen, |
405 | secret, hashlen, 1)) { |
406 | /* SSLfatal() already called */ |
407 | goto err; |
408 | } |
409 | |
410 | /* TODO(size_t): convert me */ |
411 | keylen = EVP_CIPHER_key_length(ciph); |
412 | if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) { |
413 | uint32_t algenc; |
414 | |
415 | ivlen = EVP_CCM_TLS_IV_LEN; |
416 | if (s->s3.tmp.new_cipher == NULL) { |
417 | /* We've not selected a cipher yet - we must be doing early data */ |
418 | algenc = s->session->cipher->algorithm_enc; |
419 | } else { |
420 | algenc = s->s3.tmp.new_cipher->algorithm_enc; |
421 | } |
422 | if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8)) |
423 | taglen = EVP_CCM8_TLS_TAG_LEN; |
424 | else |
425 | taglen = EVP_CCM_TLS_TAG_LEN; |
426 | } else { |
427 | ivlen = EVP_CIPHER_iv_length(ciph); |
428 | taglen = 0; |
429 | } |
430 | |
431 | if (!tls13_derive_key(s, md, secret, key, keylen) |
432 | || !tls13_derive_iv(s, md, secret, iv, ivlen)) { |
433 | /* SSLfatal() already called */ |
434 | goto err; |
435 | } |
436 | |
437 | if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0 |
438 | || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) |
439 | || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, |
440 | taglen, NULL)) |
441 | || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) { |
442 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, |
443 | ERR_R_EVP_LIB); |
444 | goto err; |
445 | } |
446 | |
447 | return 1; |
448 | err: |
449 | OPENSSL_cleanse(key, sizeof(key)); |
450 | return 0; |
451 | } |
452 | |
453 | int tls13_change_cipher_state(SSL *s, int which) |
454 | { |
455 | #ifdef CHARSET_EBCDIC |
456 | static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; |
457 | static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; |
458 | static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; |
459 | static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; |
460 | static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; |
461 | static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; |
462 | static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; |
463 | static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; |
464 | #else |
465 | static const unsigned char client_early_traffic[] = "c e traffic" ; |
466 | static const unsigned char client_handshake_traffic[] = "c hs traffic" ; |
467 | static const unsigned char client_application_traffic[] = "c ap traffic" ; |
468 | static const unsigned char server_handshake_traffic[] = "s hs traffic" ; |
469 | static const unsigned char server_application_traffic[] = "s ap traffic" ; |
470 | static const unsigned char exporter_master_secret[] = "exp master" ; |
471 | static const unsigned char resumption_master_secret[] = "res master" ; |
472 | static const unsigned char early_exporter_master_secret[] = "e exp master" ; |
473 | #endif |
474 | unsigned char *iv; |
475 | unsigned char secret[EVP_MAX_MD_SIZE]; |
476 | unsigned char hashval[EVP_MAX_MD_SIZE]; |
477 | unsigned char *hash = hashval; |
478 | unsigned char *insecret; |
479 | unsigned char *finsecret = NULL; |
480 | const char *log_label = NULL; |
481 | EVP_CIPHER_CTX *ciph_ctx; |
482 | size_t finsecretlen = 0; |
483 | const unsigned char *label; |
484 | size_t labellen, hashlen = 0; |
485 | int ret = 0; |
486 | const EVP_MD *md = NULL; |
487 | const EVP_CIPHER *cipher = NULL; |
488 | |
489 | if (which & SSL3_CC_READ) { |
490 | if (s->enc_read_ctx != NULL) { |
491 | EVP_CIPHER_CTX_reset(s->enc_read_ctx); |
492 | } else { |
493 | s->enc_read_ctx = EVP_CIPHER_CTX_new(); |
494 | if (s->enc_read_ctx == NULL) { |
495 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
496 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); |
497 | goto err; |
498 | } |
499 | } |
500 | ciph_ctx = s->enc_read_ctx; |
501 | iv = s->read_iv; |
502 | |
503 | RECORD_LAYER_reset_read_sequence(&s->rlayer); |
504 | } else { |
505 | s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; |
506 | if (s->enc_write_ctx != NULL) { |
507 | EVP_CIPHER_CTX_reset(s->enc_write_ctx); |
508 | } else { |
509 | s->enc_write_ctx = EVP_CIPHER_CTX_new(); |
510 | if (s->enc_write_ctx == NULL) { |
511 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
512 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); |
513 | goto err; |
514 | } |
515 | } |
516 | ciph_ctx = s->enc_write_ctx; |
517 | iv = s->write_iv; |
518 | |
519 | RECORD_LAYER_reset_write_sequence(&s->rlayer); |
520 | } |
521 | |
522 | if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE)) |
523 | || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) { |
524 | if (which & SSL3_CC_EARLY) { |
525 | EVP_MD_CTX *mdctx = NULL; |
526 | long handlen; |
527 | void *hdata; |
528 | unsigned int hashlenui; |
529 | const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session); |
530 | |
531 | insecret = s->early_secret; |
532 | label = client_early_traffic; |
533 | labellen = sizeof(client_early_traffic) - 1; |
534 | log_label = CLIENT_EARLY_LABEL; |
535 | |
536 | handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata); |
537 | if (handlen <= 0) { |
538 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
539 | SSL_F_TLS13_CHANGE_CIPHER_STATE, |
540 | SSL_R_BAD_HANDSHAKE_LENGTH); |
541 | goto err; |
542 | } |
543 | |
544 | if (s->early_data_state == SSL_EARLY_DATA_CONNECTING |
545 | && s->max_early_data > 0 |
546 | && s->session->ext.max_early_data == 0) { |
547 | /* |
548 | * If we are attempting to send early data, and we've decided to |
549 | * actually do it but max_early_data in s->session is 0 then we |
550 | * must be using an external PSK. |
551 | */ |
552 | if (!ossl_assert(s->psksession != NULL |
553 | && s->max_early_data == |
554 | s->psksession->ext.max_early_data)) { |
555 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
556 | SSL_F_TLS13_CHANGE_CIPHER_STATE, |
557 | ERR_R_INTERNAL_ERROR); |
558 | goto err; |
559 | } |
560 | sslcipher = SSL_SESSION_get0_cipher(s->psksession); |
561 | } |
562 | if (sslcipher == NULL) { |
563 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
564 | SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK); |
565 | goto err; |
566 | } |
567 | |
568 | /* |
569 | * We need to calculate the handshake digest using the digest from |
570 | * the session. We haven't yet selected our ciphersuite so we can't |
571 | * use ssl_handshake_md(). |
572 | */ |
573 | mdctx = EVP_MD_CTX_new(); |
574 | if (mdctx == NULL) { |
575 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
576 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); |
577 | goto err; |
578 | } |
579 | cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher)); |
580 | md = ssl_md(sslcipher->algorithm2); |
581 | if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL) |
582 | || !EVP_DigestUpdate(mdctx, hdata, handlen) |
583 | || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) { |
584 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
585 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); |
586 | EVP_MD_CTX_free(mdctx); |
587 | goto err; |
588 | } |
589 | hashlen = hashlenui; |
590 | EVP_MD_CTX_free(mdctx); |
591 | |
592 | if (!tls13_hkdf_expand(s, md, insecret, |
593 | early_exporter_master_secret, |
594 | sizeof(early_exporter_master_secret) - 1, |
595 | hashval, hashlen, |
596 | s->early_exporter_master_secret, hashlen, |
597 | 1)) { |
598 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
599 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); |
600 | goto err; |
601 | } |
602 | |
603 | if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL, |
604 | s->early_exporter_master_secret, hashlen)) { |
605 | /* SSLfatal() already called */ |
606 | goto err; |
607 | } |
608 | } else if (which & SSL3_CC_HANDSHAKE) { |
609 | insecret = s->handshake_secret; |
610 | finsecret = s->client_finished_secret; |
611 | finsecretlen = EVP_MD_size(ssl_handshake_md(s)); |
612 | label = client_handshake_traffic; |
613 | labellen = sizeof(client_handshake_traffic) - 1; |
614 | log_label = CLIENT_HANDSHAKE_LABEL; |
615 | /* |
616 | * The handshake hash used for the server read/client write handshake |
617 | * traffic secret is the same as the hash for the server |
618 | * write/client read handshake traffic secret. However, if we |
619 | * processed early data then we delay changing the server |
620 | * read/client write cipher state until later, and the handshake |
621 | * hashes have moved on. Therefore we use the value saved earlier |
622 | * when we did the server write/client read change cipher state. |
623 | */ |
624 | hash = s->handshake_traffic_hash; |
625 | } else { |
626 | insecret = s->master_secret; |
627 | label = client_application_traffic; |
628 | labellen = sizeof(client_application_traffic) - 1; |
629 | log_label = CLIENT_APPLICATION_LABEL; |
630 | /* |
631 | * For this we only use the handshake hashes up until the server |
632 | * Finished hash. We do not include the client's Finished, which is |
633 | * what ssl_handshake_hash() would give us. Instead we use the |
634 | * previously saved value. |
635 | */ |
636 | hash = s->server_finished_hash; |
637 | } |
638 | } else { |
639 | /* Early data never applies to client-read/server-write */ |
640 | if (which & SSL3_CC_HANDSHAKE) { |
641 | insecret = s->handshake_secret; |
642 | finsecret = s->server_finished_secret; |
643 | finsecretlen = EVP_MD_size(ssl_handshake_md(s)); |
644 | label = server_handshake_traffic; |
645 | labellen = sizeof(server_handshake_traffic) - 1; |
646 | log_label = SERVER_HANDSHAKE_LABEL; |
647 | } else { |
648 | insecret = s->master_secret; |
649 | label = server_application_traffic; |
650 | labellen = sizeof(server_application_traffic) - 1; |
651 | log_label = SERVER_APPLICATION_LABEL; |
652 | } |
653 | } |
654 | |
655 | if (!(which & SSL3_CC_EARLY)) { |
656 | md = ssl_handshake_md(s); |
657 | cipher = s->s3.tmp.new_sym_enc; |
658 | if (!ssl3_digest_cached_records(s, 1) |
659 | || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) { |
660 | /* SSLfatal() already called */; |
661 | goto err; |
662 | } |
663 | } |
664 | |
665 | /* |
666 | * Save the hash of handshakes up to now for use when we calculate the |
667 | * client application traffic secret |
668 | */ |
669 | if (label == server_application_traffic) |
670 | memcpy(s->server_finished_hash, hashval, hashlen); |
671 | |
672 | if (label == server_handshake_traffic) |
673 | memcpy(s->handshake_traffic_hash, hashval, hashlen); |
674 | |
675 | if (label == client_application_traffic) { |
676 | /* |
677 | * We also create the resumption master secret, but this time use the |
678 | * hash for the whole handshake including the Client Finished |
679 | */ |
680 | if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, |
681 | resumption_master_secret, |
682 | sizeof(resumption_master_secret) - 1, |
683 | hashval, hashlen, s->resumption_master_secret, |
684 | hashlen, 1)) { |
685 | /* SSLfatal() already called */ |
686 | goto err; |
687 | } |
688 | } |
689 | |
690 | if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, |
691 | insecret, hash, label, labellen, secret, iv, |
692 | ciph_ctx)) { |
693 | /* SSLfatal() already called */ |
694 | goto err; |
695 | } |
696 | |
697 | if (label == server_application_traffic) { |
698 | memcpy(s->server_app_traffic_secret, secret, hashlen); |
699 | /* Now we create the exporter master secret */ |
700 | if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, |
701 | exporter_master_secret, |
702 | sizeof(exporter_master_secret) - 1, |
703 | hash, hashlen, s->exporter_master_secret, |
704 | hashlen, 1)) { |
705 | /* SSLfatal() already called */ |
706 | goto err; |
707 | } |
708 | |
709 | if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret, |
710 | hashlen)) { |
711 | /* SSLfatal() already called */ |
712 | goto err; |
713 | } |
714 | } else if (label == client_application_traffic) |
715 | memcpy(s->client_app_traffic_secret, secret, hashlen); |
716 | |
717 | if (!ssl_log_secret(s, log_label, secret, hashlen)) { |
718 | /* SSLfatal() already called */ |
719 | goto err; |
720 | } |
721 | |
722 | if (finsecret != NULL |
723 | && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret, |
724 | finsecret, finsecretlen)) { |
725 | /* SSLfatal() already called */ |
726 | goto err; |
727 | } |
728 | |
729 | if (!s->server && label == client_early_traffic) |
730 | s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS; |
731 | else |
732 | s->statem.enc_write_state = ENC_WRITE_STATE_VALID; |
733 | ret = 1; |
734 | err: |
735 | OPENSSL_cleanse(secret, sizeof(secret)); |
736 | return ret; |
737 | } |
738 | |
739 | int tls13_update_key(SSL *s, int sending) |
740 | { |
741 | #ifdef CHARSET_EBCDIC |
742 | static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00}; |
743 | #else |
744 | static const unsigned char application_traffic[] = "traffic upd" ; |
745 | #endif |
746 | const EVP_MD *md = ssl_handshake_md(s); |
747 | size_t hashlen = EVP_MD_size(md); |
748 | unsigned char *insecret, *iv; |
749 | unsigned char secret[EVP_MAX_MD_SIZE]; |
750 | EVP_CIPHER_CTX *ciph_ctx; |
751 | int ret = 0; |
752 | |
753 | if (s->server == sending) |
754 | insecret = s->server_app_traffic_secret; |
755 | else |
756 | insecret = s->client_app_traffic_secret; |
757 | |
758 | if (sending) { |
759 | s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; |
760 | iv = s->write_iv; |
761 | ciph_ctx = s->enc_write_ctx; |
762 | RECORD_LAYER_reset_write_sequence(&s->rlayer); |
763 | } else { |
764 | iv = s->read_iv; |
765 | ciph_ctx = s->enc_read_ctx; |
766 | RECORD_LAYER_reset_read_sequence(&s->rlayer); |
767 | } |
768 | |
769 | if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s), |
770 | s->s3.tmp.new_sym_enc, insecret, NULL, |
771 | application_traffic, |
772 | sizeof(application_traffic) - 1, secret, iv, |
773 | ciph_ctx)) { |
774 | /* SSLfatal() already called */ |
775 | goto err; |
776 | } |
777 | |
778 | memcpy(insecret, secret, hashlen); |
779 | |
780 | s->statem.enc_write_state = ENC_WRITE_STATE_VALID; |
781 | ret = 1; |
782 | err: |
783 | OPENSSL_cleanse(secret, sizeof(secret)); |
784 | return ret; |
785 | } |
786 | |
787 | int tls13_alert_code(int code) |
788 | { |
789 | /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */ |
790 | if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED) |
791 | return code; |
792 | |
793 | return tls1_alert_code(code); |
794 | } |
795 | |
796 | int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, |
797 | const char *label, size_t llen, |
798 | const unsigned char *context, |
799 | size_t contextlen, int use_context) |
800 | { |
801 | unsigned char exportsecret[EVP_MAX_MD_SIZE]; |
802 | #ifdef CHARSET_EBCDIC |
803 | static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; |
804 | #else |
805 | static const unsigned char exporterlabel[] = "exporter" ; |
806 | #endif |
807 | unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; |
808 | const EVP_MD *md = ssl_handshake_md(s); |
809 | EVP_MD_CTX *ctx = EVP_MD_CTX_new(); |
810 | unsigned int hashsize, datalen; |
811 | int ret = 0; |
812 | |
813 | if (ctx == NULL || !ossl_statem_export_allowed(s)) |
814 | goto err; |
815 | |
816 | if (!use_context) |
817 | contextlen = 0; |
818 | |
819 | if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 |
820 | || EVP_DigestUpdate(ctx, context, contextlen) <= 0 |
821 | || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 |
822 | || EVP_DigestInit_ex(ctx, md, NULL) <= 0 |
823 | || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 |
824 | || !tls13_hkdf_expand(s, md, s->exporter_master_secret, |
825 | (const unsigned char *)label, llen, |
826 | data, datalen, exportsecret, hashsize, 0) |
827 | || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, |
828 | sizeof(exporterlabel) - 1, hash, hashsize, |
829 | out, olen, 0)) |
830 | goto err; |
831 | |
832 | ret = 1; |
833 | err: |
834 | EVP_MD_CTX_free(ctx); |
835 | return ret; |
836 | } |
837 | |
838 | int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, |
839 | const char *label, size_t llen, |
840 | const unsigned char *context, |
841 | size_t contextlen) |
842 | { |
843 | #ifdef CHARSET_EBCDIC |
844 | static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; |
845 | #else |
846 | static const unsigned char exporterlabel[] = "exporter" ; |
847 | #endif |
848 | unsigned char exportsecret[EVP_MAX_MD_SIZE]; |
849 | unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; |
850 | const EVP_MD *md; |
851 | EVP_MD_CTX *ctx = EVP_MD_CTX_new(); |
852 | unsigned int hashsize, datalen; |
853 | int ret = 0; |
854 | const SSL_CIPHER *sslcipher; |
855 | |
856 | if (ctx == NULL || !ossl_statem_export_early_allowed(s)) |
857 | goto err; |
858 | |
859 | if (!s->server && s->max_early_data > 0 |
860 | && s->session->ext.max_early_data == 0) |
861 | sslcipher = SSL_SESSION_get0_cipher(s->psksession); |
862 | else |
863 | sslcipher = SSL_SESSION_get0_cipher(s->session); |
864 | |
865 | md = ssl_md(sslcipher->algorithm2); |
866 | |
867 | /* |
868 | * Calculate the hash value and store it in |data|. The reason why |
869 | * the empty string is used is that the definition of TLS-Exporter |
870 | * is like so: |
871 | * |
872 | * TLS-Exporter(label, context_value, key_length) = |
873 | * HKDF-Expand-Label(Derive-Secret(Secret, label, ""), |
874 | * "exporter", Hash(context_value), key_length) |
875 | * |
876 | * Derive-Secret(Secret, Label, Messages) = |
877 | * HKDF-Expand-Label(Secret, Label, |
878 | * Transcript-Hash(Messages), Hash.length) |
879 | * |
880 | * Here Transcript-Hash is the cipher suite hash algorithm. |
881 | */ |
882 | if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 |
883 | || EVP_DigestUpdate(ctx, context, contextlen) <= 0 |
884 | || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 |
885 | || EVP_DigestInit_ex(ctx, md, NULL) <= 0 |
886 | || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 |
887 | || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret, |
888 | (const unsigned char *)label, llen, |
889 | data, datalen, exportsecret, hashsize, 0) |
890 | || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, |
891 | sizeof(exporterlabel) - 1, hash, hashsize, |
892 | out, olen, 0)) |
893 | goto err; |
894 | |
895 | ret = 1; |
896 | err: |
897 | EVP_MD_CTX_free(ctx); |
898 | return ret; |
899 | } |
900 | |