1*641ead6dSzrj /* $OpenBSD: timingsafe_bcmp.c,v 1.3 2015/08/31 02:53:57 guenther Exp $ */
2*641ead6dSzrj /*
3*641ead6dSzrj * Copyright (c) 2010 Damien Miller. All rights reserved.
4*641ead6dSzrj *
5*641ead6dSzrj * Permission to use, copy, modify, and distribute this software for any
6*641ead6dSzrj * purpose with or without fee is hereby granted, provided that the above
7*641ead6dSzrj * copyright notice and this permission notice appear in all copies.
8*641ead6dSzrj *
9*641ead6dSzrj * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10*641ead6dSzrj * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11*641ead6dSzrj * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12*641ead6dSzrj * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13*641ead6dSzrj * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14*641ead6dSzrj * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15*641ead6dSzrj * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16*641ead6dSzrj */
17*641ead6dSzrj
18*641ead6dSzrj #include <string.h>
19*641ead6dSzrj
20*641ead6dSzrj int
timingsafe_bcmp(const void * b1,const void * b2,size_t n)21*641ead6dSzrj timingsafe_bcmp(const void *b1, const void *b2, size_t n)
22*641ead6dSzrj {
23*641ead6dSzrj const unsigned char *p1 = b1, *p2 = b2;
24*641ead6dSzrj int ret = 0;
25*641ead6dSzrj
26*641ead6dSzrj for (; n > 0; n--)
27*641ead6dSzrj ret |= *p1++ ^ *p2++;
28*641ead6dSzrj return (ret != 0);
29*641ead6dSzrj }
30