1/*	$OpenBSD: timingsafe_bcmp.c,v 1.2 2014/06/10 04:16:57 deraadt Exp $	*/
2/*
3 * Copyright (c) 2010 Damien Miller.  All rights reserved.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 *
17 */
18
19#include <sys/libkern.h>
20
21int
22timingsafe_bcmp(const void *b1, const void *b2, size_t n)
23{
24	const unsigned char *p1 = b1, *p2 = b2;
25	int ret = 0;
26
27	for (; n > 0; n--)
28		ret |= *p1++ ^ *p2++;
29	return (ret != 0);
30}
31