1 /* $OpenBSD: timingsafe_bcmp.c,v 1.3 2015/08/31 02:53:57 guenther 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 <sys/cdefs.h> 19 __FBSDID("$FreeBSD$"); 20 21 #include <string.h> 22 23 int __timingsafe_bcmp(const void *, const void *, size_t); 24 25 int 26 __timingsafe_bcmp(const void *b1, const void *b2, size_t n) 27 { 28 const unsigned char *p1 = b1, *p2 = b2; 29 int ret = 0; 30 31 for (; n > 0; n--) 32 ret |= *p1++ ^ *p2++; 33 return (ret != 0); 34 } 35 36 __weak_reference(__timingsafe_bcmp, timingsafe_bcmp); 37