summaryrefslogtreecommitdiff
path: root/src/lib/libssl/tls12_key_schedule.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/libssl/tls12_key_schedule.c')
-rw-r--r--src/lib/libssl/tls12_key_schedule.c295
1 files changed, 0 insertions, 295 deletions
diff --git a/src/lib/libssl/tls12_key_schedule.c b/src/lib/libssl/tls12_key_schedule.c
deleted file mode 100644
index 6d714c1183..0000000000
--- a/src/lib/libssl/tls12_key_schedule.c
+++ /dev/null
@@ -1,295 +0,0 @@
1/* $OpenBSD: tls12_key_schedule.c,v 1.3 2022/11/26 16:08:56 tb Exp $ */
2/*
3 * Copyright (c) 2021 Joel Sing <jsing@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include <stdlib.h>
19
20#include <openssl/evp.h>
21
22#include "bytestring.h"
23#include "ssl_local.h"
24#include "tls12_internal.h"
25
26struct tls12_key_block {
27 CBS client_write_mac_key;
28 CBS server_write_mac_key;
29 CBS client_write_key;
30 CBS server_write_key;
31 CBS client_write_iv;
32 CBS server_write_iv;
33
34 uint8_t *key_block;
35 size_t key_block_len;
36};
37
38struct tls12_key_block *
39tls12_key_block_new(void)
40{
41 return calloc(1, sizeof(struct tls12_key_block));
42}
43
44static void
45tls12_key_block_clear(struct tls12_key_block *kb)
46{
47 CBS_init(&kb->client_write_mac_key, NULL, 0);
48 CBS_init(&kb->server_write_mac_key, NULL, 0);
49 CBS_init(&kb->client_write_key, NULL, 0);
50 CBS_init(&kb->server_write_key, NULL, 0);
51 CBS_init(&kb->client_write_iv, NULL, 0);
52 CBS_init(&kb->server_write_iv, NULL, 0);
53
54 freezero(kb->key_block, kb->key_block_len);
55 kb->key_block = NULL;
56 kb->key_block_len = 0;
57}
58
59void
60tls12_key_block_free(struct tls12_key_block *kb)
61{
62 if (kb == NULL)
63 return;
64
65 tls12_key_block_clear(kb);
66
67 freezero(kb, sizeof(struct tls12_key_block));
68}
69
70void
71tls12_key_block_client_write(struct tls12_key_block *kb, CBS *mac_key,
72 CBS *key, CBS *iv)
73{
74 CBS_dup(&kb->client_write_mac_key, mac_key);
75 CBS_dup(&kb->client_write_key, key);
76 CBS_dup(&kb->client_write_iv, iv);
77}
78
79void
80tls12_key_block_server_write(struct tls12_key_block *kb, CBS *mac_key,
81 CBS *key, CBS *iv)
82{
83 CBS_dup(&kb->server_write_mac_key, mac_key);
84 CBS_dup(&kb->server_write_key, key);
85 CBS_dup(&kb->server_write_iv, iv);
86}
87
88int
89tls12_key_block_generate(struct tls12_key_block *kb, SSL *s,
90 const EVP_AEAD *aead, const EVP_CIPHER *cipher, const EVP_MD *mac_hash)
91{
92 size_t mac_key_len = 0, key_len = 0, iv_len = 0;
93 uint8_t *key_block = NULL;
94 size_t key_block_len = 0;
95 CBS cbs;
96
97 /*
98 * Generate a TLSv1.2 key block and partition into individual secrets,
99 * as per RFC 5246 section 6.3.
100 */
101
102 tls12_key_block_clear(kb);
103
104 /* Must have AEAD or cipher/MAC pair. */
105 if (aead == NULL && (cipher == NULL || mac_hash == NULL))
106 goto err;
107
108 if (aead != NULL) {
109 key_len = EVP_AEAD_key_length(aead);
110
111 /* AEAD fixed nonce length. */
112 if (aead == EVP_aead_aes_128_gcm() ||
113 aead == EVP_aead_aes_256_gcm())
114 iv_len = 4;
115 else if (aead == EVP_aead_chacha20_poly1305())
116 iv_len = 12;
117 else
118 goto err;
119 } else if (cipher != NULL && mac_hash != NULL) {
120 /*
121 * A negative integer return value will be detected via the
122 * EVP_MAX_* checks against the size_t variables below.
123 */
124 mac_key_len = EVP_MD_size(mac_hash);
125 key_len = EVP_CIPHER_key_length(cipher);
126 iv_len = EVP_CIPHER_iv_length(cipher);
127
128 /* Special handling for GOST... */
129 if (EVP_MD_type(mac_hash) == NID_id_Gost28147_89_MAC)
130 mac_key_len = 32;
131 }
132
133 if (mac_key_len > EVP_MAX_MD_SIZE)
134 goto err;
135 if (key_len > EVP_MAX_KEY_LENGTH)
136 goto err;
137 if (iv_len > EVP_MAX_IV_LENGTH)
138 goto err;
139
140 key_block_len = 2 * mac_key_len + 2 * key_len + 2 * iv_len;
141 if ((key_block = calloc(1, key_block_len)) == NULL)
142 goto err;
143
144 if (!tls1_generate_key_block(s, key_block, key_block_len))
145 goto err;
146
147 kb->key_block = key_block;
148 kb->key_block_len = key_block_len;
149 key_block = NULL;
150 key_block_len = 0;
151
152 /* Partition key block into individual secrets. */
153 CBS_init(&cbs, kb->key_block, kb->key_block_len);
154 if (!CBS_get_bytes(&cbs, &kb->client_write_mac_key, mac_key_len))
155 goto err;
156 if (!CBS_get_bytes(&cbs, &kb->server_write_mac_key, mac_key_len))
157 goto err;
158 if (!CBS_get_bytes(&cbs, &kb->client_write_key, key_len))
159 goto err;
160 if (!CBS_get_bytes(&cbs, &kb->server_write_key, key_len))
161 goto err;
162 if (!CBS_get_bytes(&cbs, &kb->client_write_iv, iv_len))
163 goto err;
164 if (!CBS_get_bytes(&cbs, &kb->server_write_iv, iv_len))
165 goto err;
166 if (CBS_len(&cbs) != 0)
167 goto err;
168
169 return 1;
170
171 err:
172 tls12_key_block_clear(kb);
173 freezero(key_block, key_block_len);
174
175 return 0;
176}
177
178struct tls12_reserved_label {
179 const char *label;
180 size_t label_len;
181};
182
183/*
184 * RFC 5705 section 6.
185 */
186static const struct tls12_reserved_label tls12_reserved_labels[] = {
187 {
188 .label = TLS_MD_CLIENT_FINISH_CONST,
189 .label_len = TLS_MD_CLIENT_FINISH_CONST_SIZE,
190 },
191 {
192 .label = TLS_MD_SERVER_FINISH_CONST,
193 .label_len = TLS_MD_SERVER_FINISH_CONST_SIZE,
194 },
195 {
196 .label = TLS_MD_MASTER_SECRET_CONST,
197 .label_len = TLS_MD_MASTER_SECRET_CONST_SIZE,
198 },
199 {
200 .label = TLS_MD_KEY_EXPANSION_CONST,
201 .label_len = TLS_MD_KEY_EXPANSION_CONST_SIZE,
202 },
203 {
204 .label = NULL,
205 .label_len = 0,
206 },
207};
208
209int
210tls12_exporter(SSL *s, const uint8_t *label, size_t label_len,
211 const uint8_t *context_value, size_t context_value_len, int use_context,
212 uint8_t *out, size_t out_len)
213{
214 uint8_t *data = NULL;
215 size_t data_len = 0;
216 CBB cbb, context;
217 CBS seed;
218 size_t i;
219 int ret = 0;
220
221 /*
222 * RFC 5705 - Key Material Exporters for TLS.
223 */
224
225 memset(&cbb, 0, sizeof(cbb));
226
227 if (!SSL_is_init_finished(s)) {
228 SSLerror(s, SSL_R_BAD_STATE);
229 goto err;
230 }
231
232 if (s->s3->hs.negotiated_tls_version >= TLS1_3_VERSION)
233 goto err;
234
235 /*
236 * Due to exceptional design choices, we need to build a concatenation
237 * of the label and the seed value, before checking for reserved
238 * labels. This prevents a reserved label from being split across the
239 * label and the seed (that includes the client random), which are
240 * concatenated by the PRF.
241 */
242 if (!CBB_init(&cbb, 0))
243 goto err;
244 if (!CBB_add_bytes(&cbb, label, label_len))
245 goto err;
246 if (!CBB_add_bytes(&cbb, s->s3->client_random, SSL3_RANDOM_SIZE))
247 goto err;
248 if (!CBB_add_bytes(&cbb, s->s3->server_random, SSL3_RANDOM_SIZE))
249 goto err;
250 if (use_context) {
251 if (!CBB_add_u16_length_prefixed(&cbb, &context))
252 goto err;
253 if (context_value_len > 0) {
254 if (!CBB_add_bytes(&context, context_value,
255 context_value_len))
256 goto err;
257 }
258 }
259 if (!CBB_finish(&cbb, &data, &data_len))
260 goto err;
261
262 /*
263 * Ensure that the block (label + seed) does not start with a reserved
264 * label - in an ideal world we would ensure that the label has an
265 * explicitly permitted prefix instead, but of course this also got
266 * messed up by the standards.
267 */
268 for (i = 0; tls12_reserved_labels[i].label != NULL; i++) {
269 /* XXX - consider adding/using CBS_has_prefix(). */
270 if (tls12_reserved_labels[i].label_len > data_len)
271 goto err;
272 if (memcmp(data, tls12_reserved_labels[i].label,
273 tls12_reserved_labels[i].label_len) == 0) {
274 SSLerror(s, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
275 goto err;
276 }
277 }
278
279 CBS_init(&seed, data, data_len);
280 if (!CBS_skip(&seed, label_len))
281 goto err;
282
283 if (!tls1_PRF(s, s->session->master_key, s->session->master_key_length,
284 label, label_len, CBS_data(&seed), CBS_len(&seed), NULL, 0, NULL, 0,
285 NULL, 0, out, out_len))
286 goto err;
287
288 ret = 1;
289
290 err:
291 freezero(data, data_len);
292 CBB_cleanup(&cbb);
293
294 return ret;
295}
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2026-02-11 15:01:14 +0000