1/*	$OpenBSD: hmac_sha1.c,v 1.1 2012/10/09 12:36:50 jsing Exp $	*/
2
3/*-
4 * Copyright (c) 2008 Damien Bergamini <damien.bergamini@free.fr>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/param.h>
20
21#include <lib/libsa/stand.h>
22
23#include "hmac_sha1.h"
24
25/*
26 * HMAC-SHA-1 (from RFC 2202).
27 */
28void
29hmac_sha1(const u_int8_t *text, size_t text_len, const u_int8_t *key,
30    size_t key_len, u_int8_t digest[SHA1_DIGEST_LENGTH])
31{
32	SHA1_CTX ctx;
33	u_int8_t k_pad[SHA1_BLOCK_LENGTH];
34	u_int8_t tk[SHA1_DIGEST_LENGTH];
35	int i;
36
37	if (key_len > SHA1_BLOCK_LENGTH) {
38		SHA1Init(&ctx);
39		SHA1Update(&ctx, key, key_len);
40		SHA1Final(tk, &ctx);
41
42		key = tk;
43		key_len = SHA1_DIGEST_LENGTH;
44	}
45
46	bzero(k_pad, sizeof k_pad);
47	bcopy(key, k_pad, key_len);
48	for (i = 0; i < SHA1_BLOCK_LENGTH; i++)
49		k_pad[i] ^= 0x36;
50
51	SHA1Init(&ctx);
52	SHA1Update(&ctx, k_pad, SHA1_BLOCK_LENGTH);
53	SHA1Update(&ctx, text, text_len);
54	SHA1Final(digest, &ctx);
55
56	bzero(k_pad, sizeof k_pad);
57	bcopy(key, k_pad, key_len);
58	for (i = 0; i < SHA1_BLOCK_LENGTH; i++)
59		k_pad[i] ^= 0x5c;
60
61	SHA1Init(&ctx);
62	SHA1Update(&ctx, k_pad, SHA1_BLOCK_LENGTH);
63	SHA1Update(&ctx, digest, SHA1_DIGEST_LENGTH);
64	SHA1Final(digest, &ctx);
65}
66