1 /* $OpenBSD: timingsafe_bcmp.c,v 1.2 2014/06/10 04:17:37 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 #include <string.h>
19
20 int
timingsafe_bcmp(const void * b1,const void * b2,size_t n)21 timingsafe_bcmp(const void *b1, const void *b2, size_t n)
22 {
23 const unsigned char *p1 = b1, *p2 = b2;
24 int ret = 0;
25
26 for (; n > 0; n--)
27 ret |= *p1++ ^ *p2++;
28 return (ret != 0);
29 }
30
