1 /* $NetBSD: pkcs5.c,v 1.1.1.1 2011/04/13 18:14:50 elric Exp $ */
2
3 /*
4 * Copyright (c) 2006 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <config.h>
37
38 #ifdef KRB5
39 #include <krb5/krb5-types.h>
40 #endif
41
42 #include <stdio.h>
43 #include <stdlib.h>
44
45 #include <evp.h>
46 #include <hmac.h>
47
48 #include <krb5/roken.h>
49
50 /**
51 * As descriped in PKCS5, convert a password, salt, and iteration counter into a crypto key.
52 *
53 * @param password Password.
54 * @param password_len Length of password.
55 * @param salt Salt
56 * @param salt_len Length of salt.
57 * @param iter iteration counter.
58 * @param keylen the output key length.
59 * @param key the output key.
60 *
61 * @return 1 on success, non 1 on failure.
62 *
63 * @ingroup hcrypto_misc
64 */
65
66 int
PKCS5_PBKDF2_HMAC_SHA1(const void * password,size_t password_len,const void * salt,size_t salt_len,unsigned long iter,size_t keylen,void * key)67 PKCS5_PBKDF2_HMAC_SHA1(const void * password, size_t password_len,
68 const void * salt, size_t salt_len,
69 unsigned long iter,
70 size_t keylen, void *key)
71 {
72 size_t datalen, leftofkey, checksumsize;
73 char *data, *tmpcksum;
74 uint32_t keypart;
75 const EVP_MD *md;
76 unsigned long i;
77 int j;
78 char *p;
79 unsigned int hmacsize;
80
81 md = EVP_sha1();
82 checksumsize = EVP_MD_size(md);
83 datalen = salt_len + 4;
84
85 tmpcksum = malloc(checksumsize + datalen);
86 if (tmpcksum == NULL)
87 return 0;
88
89 data = &tmpcksum[checksumsize];
90
91 memcpy(data, salt, salt_len);
92
93 keypart = 1;
94 leftofkey = keylen;
95 p = key;
96
97 while (leftofkey) {
98 int len;
99
100 if (leftofkey > checksumsize)
101 len = checksumsize;
102 else
103 len = leftofkey;
104
105 data[datalen - 4] = (keypart >> 24) & 0xff;
106 data[datalen - 3] = (keypart >> 16) & 0xff;
107 data[datalen - 2] = (keypart >> 8) & 0xff;
108 data[datalen - 1] = (keypart) & 0xff;
109
110 HMAC(md, password, password_len, data, datalen,
111 tmpcksum, &hmacsize);
112
113 memcpy(p, tmpcksum, len);
114 for (i = 1; i < iter; i++) {
115 HMAC(md, password, password_len, tmpcksum, checksumsize,
116 tmpcksum, &hmacsize);
117
118 for (j = 0; j < len; j++)
119 p[j] ^= tmpcksum[j];
120 }
121
122 p += len;
123 leftofkey -= len;
124 keypart++;
125 }
126
127 free(tmpcksum);
128
129 return 1;
130 }
131