hash.c revision 91600 
1/*-
2 * Copyright (c) 2000 Mark R V Murray
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/dev/random/hash.c 91600 2002-03-03 19:44:22Z markm $
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31
32#include <crypto/rijndael/rijndael.h>
33
34#include <dev/random/hash.h>
35
36/* initialise the hash by zeroing it */
37void
38yarrow_hash_init(struct yarrowhash *context)
39{
40	rijndael_cipherInit(&context->cipher, MODE_CBC, NULL);
41	bzero(context->hash, KEYSIZE);
42	context->partial = 0;
43}
44
45/* Do a Davies-Meyer hash using a block cipher.
46 * H_0 = I
47 * H_i = E_M_i(H_i-1) ^ H_i-1
48 */
49void
50yarrow_hash_iterate(struct yarrowhash *context, void *data, size_t size)
51{
52	u_char temp[KEYSIZE];
53	u_int i, j;
54	union {
55		void *pv;
56		char *pc;
57	} trans;
58
59	trans.pv = data;
60	for (i = 0; i < size; i++) {
61		context->accum[context->partial++] = trans.pc[i];
62		if (context->partial == (KEYSIZE - 1)) {
63			rijndael_makeKey(&context->hashkey, DIR_ENCRYPT,
64				KEYSIZE*8, context->accum);
65			rijndael_blockEncrypt(&context->cipher,
66				&context->hashkey, context->hash,
67				KEYSIZE*8, temp);
68			for (j = 0; j < KEYSIZE; j++)
69				context->hash[j] ^= temp[j];
70			bzero(context->accum, KEYSIZE);
71			context->partial = 0;
72		}
73	}
74}
75
76/* Conclude by returning the hash in the supplied /buf/ which must be
77 * KEYSIZE bytes long. Trailing data (less than KEYSIZE bytes) are
78 * not forgotten.
79 */
80void
81yarrow_hash_finish(struct yarrowhash *context, void *buf)
82{
83	u_char temp[KEYSIZE];
84	int i;
85
86	if (context->partial) {
87		rijndael_makeKey(&context->hashkey, DIR_ENCRYPT,
88			KEYSIZE*8, context->accum);
89		rijndael_blockEncrypt(&context->cipher,
90			&context->hashkey, context->hash,
91			KEYSIZE*8, temp);
92		for (i = 0; i < KEYSIZE; i++)
93			context->hash[i] ^= temp[i];
94	}
95	memcpy(buf, context->hash, KEYSIZE);
96	bzero(context->hash, KEYSIZE);
97}
98
99/* Initialise the encryption routine by setting up the key schedule
100 * from the supplied /key/ which must be KEYSIZE bytes of binary
101 * data.
102 */
103void
104yarrow_encrypt_init(struct yarrowkey *context, void *data)
105{
106	rijndael_cipherInit(&context->cipher, MODE_CBC, NULL);
107	rijndael_makeKey(&context->key, DIR_ENCRYPT, KEYSIZE*8, data);
108}
109
110/* Encrypt the supplied data using the key schedule preset in the context.
111 * KEYSIZE bytes are encrypted from /d_in/ to /d_out/.
112 */
113void
114yarrow_encrypt(struct yarrowkey *context, void *d_in, void *d_out)
115{
116	rijndael_blockEncrypt(&context->cipher, &context->key, d_in,
117		KEYSIZE*8, d_out);
118}
119