safe_bcmp.c

/*
 +----------------------------------------------------------------------+
 | Copyright (c) The PHP Group |
 +----------------------------------------------------------------------+
 | This source file is subject to version 3.01 of the PHP license, |
 | that is bundled with this package in the file LICENSE, and is |
 | available through the world-wide-web at the following url: |
 | https://www.php.net/license/3_01.txt |
 | If you did not receive a copy of the PHP license and are unable to |
 | obtain it through the world-wide-web, please send a note to |
 | license@php.net so we can mail you a copy immediately. |
 +----------------------------------------------------------------------+
 | Author: David Carlier <devnexen@gmail.com> |
 +----------------------------------------------------------------------+
*/

#include"php.h"

#include<string.h>

/*
 * Returns 0 if both inputs match, non-zero if they don't.
 * Returns -1 early if inputs do not have the same lengths.
 *
 */
PHPAPIintphp_safe_bcmp(constzend_string*a, constzend_string*b)
{
constvolatileunsigned char*ua= (constvolatileunsigned char*)ZSTR_VAL(a);
constvolatileunsigned char*ub= (constvolatileunsigned char*)ZSTR_VAL(b);
size_ti=0;
intr=0;

if (ZSTR_LEN(a) !=ZSTR_LEN(b)) {
return-1;
 }

/* This is security sensitive code. Do not optimize this for speed. */
while (i<ZSTR_LEN(a)) {
r |= ua[i] ^ ub[i];
++i;
 }

returnr;
}