1*b5be37d2Sderaadt /* $OpenBSD: timingsafe_bcmp.c,v 1.2 2014/06/10 04:16:57 deraadt Exp $ */
2bee02badSmatthew /*
3bee02badSmatthew * Copyright (c) 2010 Damien Miller. All rights reserved.
4bee02badSmatthew *
5bee02badSmatthew * Permission to use, copy, modify, and distribute this software for any
6bee02badSmatthew * purpose with or without fee is hereby granted, provided that the above
7bee02badSmatthew * copyright notice and this permission notice appear in all copies.
8bee02badSmatthew *
9bee02badSmatthew * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10bee02badSmatthew * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11bee02badSmatthew * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12bee02badSmatthew * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13bee02badSmatthew * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14bee02badSmatthew * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15bee02badSmatthew * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16bee02badSmatthew */
17bee02badSmatthew
18bee02badSmatthew #include <lib/libkern/libkern.h>
19bee02badSmatthew
20bee02badSmatthew int
timingsafe_bcmp(const void * b1,const void * b2,size_t n)21bee02badSmatthew timingsafe_bcmp(const void *b1, const void *b2, size_t n)
22bee02badSmatthew {
23bee02badSmatthew const unsigned char *p1 = b1, *p2 = b2;
24bee02badSmatthew int ret = 0;
25bee02badSmatthew
26bee02badSmatthew for (; n > 0; n--)
27bee02badSmatthew ret |= *p1++ ^ *p2++;
28bee02badSmatthew return (ret != 0);
29bee02badSmatthew }
30