incubator-nuttx/libs/libc/string/lib_timingsafe_bcmp.c

44 lines
1.6 KiB
C

/****************************************************************************
* libs/libc/string/lib_timingsafe_bcmp.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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <string.h>
/****************************************************************************
* Public Functions
****************************************************************************/
int timingsafe_bcmp(FAR const void *b1, FAR const void *b2, size_t n)
{
FAR const unsigned char *p1 = b1;
FAR const unsigned char *p2 = b2;
int ret = 0;
for (; n > 0; n--)
{
ret |= *p1++ ^ *p2++;
}
return ret != 0;
}