1/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.] */
56
57#include <openssl/cipher.h>
58
59#include <assert.h>
60
61#include <openssl/digest.h>
62#include <openssl/mem.h>
63
64
65#define PKCS5_SALT_LEN 8
66
67int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md,
68 const uint8_t *salt, const uint8_t *data, size_t data_len,
69 unsigned count, uint8_t *key, uint8_t *iv) {
70 EVP_MD_CTX c;
71 uint8_t md_buf[EVP_MAX_MD_SIZE];
72 unsigned niv, nkey, addmd = 0;
73 unsigned mds = 0, i;
74 int rv = 0;
75
76 nkey = type->key_len;
77 niv = type->iv_len;
78
79 assert(nkey <= EVP_MAX_KEY_LENGTH);
80 assert(niv <= EVP_MAX_IV_LENGTH);
81
82 if (data == NULL) {
83 return nkey;
84 }
85
86 EVP_MD_CTX_init(&c);
87 for (;;) {
88 if (!EVP_DigestInit_ex(&c, md, NULL)) {
89 return 0;
90 }
91 if (addmd++) {
92 if (!EVP_DigestUpdate(&c, md_buf, mds)) {
93 goto err;
94 }
95 }
96 if (!EVP_DigestUpdate(&c, data, data_len)) {
97 goto err;
98 }
99 if (salt != NULL) {
100 if (!EVP_DigestUpdate(&c, salt, PKCS5_SALT_LEN)) {
101 goto err;
102 }
103 }
104 if (!EVP_DigestFinal_ex(&c, md_buf, &mds)) {
105 goto err;
106 }
107
108 for (i = 1; i < count; i++) {
109 if (!EVP_DigestInit_ex(&c, md, NULL) ||
110 !EVP_DigestUpdate(&c, md_buf, mds) ||
111 !EVP_DigestFinal_ex(&c, md_buf, &mds)) {
112 goto err;
113 }
114 }
115
116 i = 0;
117 if (nkey) {
118 for (;;) {
119 if (nkey == 0 || i == mds) {
120 break;
121 }
122 if (key != NULL) {
123 *(key++) = md_buf[i];
124 }
125 nkey--;
126 i++;
127 }
128 }
129
130 if (niv && i != mds) {
131 for (;;) {
132 if (niv == 0 || i == mds) {
133 break;
134 }
135 if (iv != NULL) {
136 *(iv++) = md_buf[i];
137 }
138 niv--;
139 i++;
140 }
141 }
142 if (nkey == 0 && niv == 0) {
143 break;
144 }
145 }
146 rv = type->key_len;
147
148err:
149 EVP_MD_CTX_cleanup(&c);
150 OPENSSL_cleanse(md_buf, EVP_MAX_MD_SIZE);
151 return rv;
152}
153