1 /* $OpenBSD: hash.c,v 1.20 2005/04/08 22:32:10 cloder Exp $ */
2 /* $EOM: hash.c,v 1.10 1999/04/17 23:20:34 niklas Exp $ */
3
4 /*
5 * Copyright (c) 1998 Niels Provos. All rights reserved.
6 * Copyright (c) 1999 Niklas Hallqvist. 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 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 /*
30 * This code was written under funding by Ericsson Radio Systems.
31 */
32
33 #include <sys/param.h>
34 #include <string.h>
35 #include <md5.h>
36 #include <sha1.h>
37
38 #include "hash.h"
39 #include "log.h"
40
41 void hmac_init(struct hash *, unsigned char *, unsigned int);
42 void hmac_final(unsigned char *, struct hash *);
43
44 /* Temporary hash contexts. */
45 static union {
46 MD5_CTX md5ctx;
47 SHA1_CTX sha1ctx;
48 } Ctx, Ctx2;
49
50 /* Temporary hash digest. */
51 static unsigned char digest[HASH_MAX];
52
53 /* Encapsulation of hash functions. */
54
55 static struct hash hashes[] = {
56 {
57 HASH_MD5, 5, MD5_SIZE, (void *)&Ctx.md5ctx, digest,
58 sizeof(MD5_CTX), (void *)&Ctx2.md5ctx,
59 (void (*)(void *))MD5Init,
60 (void (*)(void *, unsigned char *, unsigned int))MD5Update,
61 (void (*)(unsigned char *, void *))MD5Final,
62 hmac_init,
63 hmac_final
64 }, {
65 HASH_SHA1, 6, SHA1_SIZE, (void *)&Ctx.sha1ctx, digest,
66 sizeof(SHA1_CTX), (void *)&Ctx2.sha1ctx,
67 (void (*)(void *))SHA1Init,
68 (void (*)(void *, unsigned char *, unsigned int))SHA1Update,
69 (void (*)(unsigned char *, void *))SHA1Final,
70 hmac_init,
71 hmac_final
72 },
73 };
74
75 struct hash *
hash_get(enum hashes hashtype)76 hash_get(enum hashes hashtype)
77 {
78 size_t i;
79
80 LOG_DBG((LOG_CRYPTO, 60, "hash_get: requested algorithm %d",
81 hashtype));
82
83 for (i = 0; i < sizeof hashes / sizeof hashes[0]; i++)
84 if (hashtype == hashes[i].type)
85 return &hashes[i];
86
87 return 0;
88 }
89
90 /*
91 * Initial a hash for HMAC usage this requires a special init function.
92 * ctx, ctx2 hold the contexts, if you want to use the hash object for
93 * something else in the meantime, be sure to store the contexts somewhere.
94 */
95
96 void
hmac_init(struct hash * hash,unsigned char * okey,unsigned int len)97 hmac_init(struct hash *hash, unsigned char *okey, unsigned int len)
98 {
99 unsigned int i, blocklen = HMAC_BLOCKLEN;
100 unsigned char key[HMAC_BLOCKLEN];
101
102 bzero(key, blocklen);
103 if (len > blocklen) {
104 /* Truncate key down to blocklen */
105 hash->Init(hash->ctx);
106 hash->Update(hash->ctx, okey, len);
107 hash->Final(key, hash->ctx);
108 } else {
109 memcpy(key, okey, len);
110 }
111
112 /* HMAC I and O pad computation */
113 for (i = 0; i < blocklen; i++)
114 key[i] ^= HMAC_IPAD_VAL;
115
116 hash->Init(hash->ctx);
117 hash->Update(hash->ctx, key, blocklen);
118
119 for (i = 0; i < blocklen; i++)
120 key[i] ^= (HMAC_IPAD_VAL ^ HMAC_OPAD_VAL);
121
122 hash->Init(hash->ctx2);
123 hash->Update(hash->ctx2, key, blocklen);
124
125 bzero(key, blocklen);
126 }
127
128 /*
129 * HMAC Final function
130 */
131
132 void
hmac_final(unsigned char * dgst,struct hash * hash)133 hmac_final(unsigned char *dgst, struct hash *hash)
134 {
135 hash->Final(dgst, hash->ctx);
136 hash->Update(hash->ctx2, dgst, hash->hashsize);
137 hash->Final(dgst, hash->ctx2);
138 }
139