minix/common/lib/libc/string/consttime_memequal.c
Lionel Sambuc 84d9c625bf Synchronize on NetBSD-CVS (2013/12/1 12:00:00 UTC)
- Fix for possible unset uid/gid in toproto
 - Fix for default mtree style
 - Update libelf
 - Importing libexecinfo
 - Resynchronize GCC, mpc, gmp, mpfr
 - build.sh: Replace params with show-params.
     This has been done as the make target has been renamed in the same
     way, while a new target named params has been added. This new
     target generates a file containing all the parameters, instead of
     printing it on the console.
 - Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
     get getservbyport() out of the inner loop

Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
2014-07-28 17:05:06 +02:00

32 lines
737 B
C

/* $NetBSD: consttime_memequal.c,v 1.4 2013/08/28 19:31:14 riastradh Exp $ */
#if !defined(_KERNEL) && !defined(_STANDALONE)
#include "namespace.h"
#include <string.h>
#ifdef __weak_alias
__weak_alias(consttime_memequal,_consttime_memequal)
#endif
#else
#include <lib/libkern/libkern.h>
#endif
int
consttime_memequal(const void *b1, const void *b2, size_t len)
{
const char *c1 = b1, *c2 = b2;
int res = 0;
while (len --)
res |= *c1++ ^ *c2++;
/*
* If the compiler for your favourite architecture generates a
* conditional branch for `!res', it will be a data-dependent
* branch, in which case this should be replaced by
*
* return (1 - (1 & ((res - 1) >> 8)));
*
* or rewritten in assembly.
*/
return !res;
}