freebsd-skq/lib/libc/string/timingsafe_bcmp.c
delphij 408f4a1ab4 Add timingsafe_bcmp and timingsafe_memcmp.
Obtained from:	OpenBSD
Reviewed by:	trasz
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D7280
2016-08-14 23:38:50 +00:00

37 lines
1.2 KiB
C

/* $OpenBSD: timingsafe_bcmp.c,v 1.3 2015/08/31 02:53:57 guenther Exp $ */
/*
* Copyright (c) 2010 Damien Miller. All rights reserved.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <string.h>
int __timingsafe_bcmp(const void *, const void *, size_t);
int
__timingsafe_bcmp(const void *b1, const void *b2, size_t n)
{
const unsigned char *p1 = b1, *p2 = b2;
int ret = 0;
for (; n > 0; n--)
ret |= *p1++ ^ *p2++;
return (ret != 0);
}
__weak_reference(__timingsafe_bcmp, timingsafe_bcmp);