1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
/* ====================================================================
* Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com). */
#include <assert.h>
#include <CNIOBoringSSL_digest.h>
#include <CNIOBoringSSL_hmac.h>
#include <CNIOBoringSSL_mem.h>
#include "internal.h"
#include "../../internal.h"
// tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246,
// section 5. It XORs |out_len| bytes to |out|, using |md| as the hash and
// |secret| as the secret. |label|, |seed1|, and |seed2| are concatenated to
// form the seed parameter. It returns true on success and false on failure.
static int tls1_P_hash(uint8_t *out, size_t out_len,
const EVP_MD *md,
const uint8_t *secret, size_t secret_len,
const char *label, size_t label_len,
const uint8_t *seed1, size_t seed1_len,
const uint8_t *seed2, size_t seed2_len) {
HMAC_CTX ctx, ctx_tmp, ctx_init;
uint8_t A1[EVP_MAX_MD_SIZE];
unsigned A1_len;
int ret = 0;
const size_t chunk = EVP_MD_size(md);
HMAC_CTX_init(&ctx);
HMAC_CTX_init(&ctx_tmp);
HMAC_CTX_init(&ctx_init);
if (!HMAC_Init_ex(&ctx_init, secret, secret_len, md, NULL) ||
!HMAC_CTX_copy_ex(&ctx, &ctx_init) ||
!HMAC_Update(&ctx, (const uint8_t *) label, label_len) ||
!HMAC_Update(&ctx, seed1, seed1_len) ||
!HMAC_Update(&ctx, seed2, seed2_len) ||
!HMAC_Final(&ctx, A1, &A1_len)) {
goto err;
}
for (;;) {
unsigned len;
uint8_t hmac[EVP_MAX_MD_SIZE];
if (!HMAC_CTX_copy_ex(&ctx, &ctx_init) ||
!HMAC_Update(&ctx, A1, A1_len) ||
// Save a copy of |ctx| to compute the next A1 value below.
(out_len > chunk && !HMAC_CTX_copy_ex(&ctx_tmp, &ctx)) ||
!HMAC_Update(&ctx, (const uint8_t *) label, label_len) ||
!HMAC_Update(&ctx, seed1, seed1_len) ||
!HMAC_Update(&ctx, seed2, seed2_len) ||
!HMAC_Final(&ctx, hmac, &len)) {
goto err;
}
assert(len == chunk);
// XOR the result into |out|.
if (len > out_len) {
len = out_len;
}
for (unsigned i = 0; i < len; i++) {
out[i] ^= hmac[i];
}
out += len;
out_len -= len;
if (out_len == 0) {
break;
}
// Calculate the next A1 value.
if (!HMAC_Final(&ctx_tmp, A1, &A1_len)) {
goto err;
}
}
ret = 1;
err:
OPENSSL_cleanse(A1, sizeof(A1));
HMAC_CTX_cleanup(&ctx);
HMAC_CTX_cleanup(&ctx_tmp);
HMAC_CTX_cleanup(&ctx_init);
return ret;
}
int CRYPTO_tls1_prf(const EVP_MD *digest,
uint8_t *out, size_t out_len,
const uint8_t *secret, size_t secret_len,
const char *label, size_t label_len,
const uint8_t *seed1, size_t seed1_len,
const uint8_t *seed2, size_t seed2_len) {
if (out_len == 0) {
return 1;
}
OPENSSL_memset(out, 0, out_len);
if (digest == EVP_md5_sha1()) {
// If using the MD5/SHA1 PRF, |secret| is partitioned between MD5 and SHA-1.
size_t secret_half = secret_len - (secret_len / 2);
if (!tls1_P_hash(out, out_len, EVP_md5(), secret, secret_half, label,
label_len, seed1, seed1_len, seed2, seed2_len)) {
return 0;
}
// Note that, if |secret_len| is odd, the two halves share a byte.
secret += secret_len - secret_half;
secret_len = secret_half;
digest = EVP_sha1();
}
return tls1_P_hash(out, out_len, digest, secret, secret_len, label, label_len,
seed1, seed1_len, seed2, seed2_len);
}
|
