hash.c revision 65686 
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 65686 2000-09-10 13:52:19Z markm $
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/queue.h>
32#include <sys/libkern.h>
33#include <sys/mbuf.h>
34#include <sys/random.h>
35#include <sys/time.h>
36#include <sys/types.h>
37#include <crypto/blowfish/blowfish.h>
38
39#include <dev/randomdev/hash.h>
40#include <dev/randomdev/yarrow.h>
41
42/* initialise the hash by copying in some supplied data */
43void
44yarrow_hash_init(struct yarrowhash *context, void *data, size_t size)
45{
46	size_t count;
47
48	count = size > KEYSIZE ? KEYSIZE : size;
49	memset(context->hash, 0xff, KEYSIZE);
50	memcpy(context->hash, data, count);
51}
52
53/* Do a Davies-Meyer hash using a block cipher.
54 * H_0 = I
55 * H_i = E_M_i(H_i-1) ^ H_i-1
56 */
57void
58yarrow_hash_iterate(struct yarrowhash *context, void *data, size_t size)
59{
60	u_char keybuffer[KEYSIZE], temp[KEYSIZE];
61	size_t count;
62	int iteration, last, i;
63
64	iteration = 0;
65	last = 0;
66	for (;;) {
67		if (size <= KEYSIZE)
68			last = 1;
69		count = size > KEYSIZE ? KEYSIZE : size;
70		memcpy(keybuffer, &((u_char *)data)[iteration], count);
71		memset(&keybuffer[KEYSIZE - count], 0xff, count);
72		BF_set_key(&context->hashkey, count,
73			&((u_char *)data)[iteration]);
74		BF_cbc_encrypt(context->hash, temp, KEYSIZE, &context->hashkey,
75			context->ivec, BF_ENCRYPT);
76		for (i = 0; i < KEYSIZE; i++)
77			context->hash[i] ^= temp[i];
78		if (last)
79			break;
80		iteration += KEYSIZE;
81		size -= KEYSIZE;
82	}
83}
84
85/* Conclude by returning a pointer to the data */
86void
87yarrow_hash_finish(struct yarrowhash *context, void *buf)
88{
89	memcpy(buf, context->hash, sizeof(context->hash));
90}
91
92/* Initialise the encryption routine by setting up the key schedule */
93void
94yarrow_encrypt_init(struct yarrowkey *context, void *data, size_t size)
95{
96	size_t count;
97
98	count = size > KEYSIZE ? KEYSIZE : size;
99	BF_set_key(&context->key, size, data);
100}
101
102/* Encrypt the supplied data using the key schedule preset in the context */
103void
104yarrow_encrypt(struct yarrowkey *context, void *d_in, void *d_out, size_t size)
105{
106	size_t count;
107	int iteration, last;
108
109	last = 0;
110	for (iteration = 0;; iteration += KEYSIZE) {
111		if (size <= KEYSIZE)
112			last = 1;
113		count = size > KEYSIZE ? KEYSIZE : size;
114		BF_cbc_encrypt(&((u_char *)d_in)[iteration],
115			&((u_char *)d_out)[iteration], count, &context->key,
116			context->ivec, BF_ENCRYPT);
117		if (last)
118			break;
119		size -= KEYSIZE;
120	}
121}
122