1 /*
2 +----------------------------------------------------------------------+
3 | Copyright (c) The PHP Group |
4 +----------------------------------------------------------------------+
5 | This source file is subject to version 3.01 of the PHP license, |
6 | that is bundled with this package in the file LICENSE, and is |
7 | available through the world-wide-web at the following url: |
8 | http://www.php.net/license/3_01.txt |
9 | If you did not receive a copy of the PHP license and are unable to |
10 | obtain it through the world-wide-web, please send a note to |
11 | license@php.net so we can mail you a copy immediately. |
12 +----------------------------------------------------------------------+
13 | Author: David Carlier <devnexen@gmail.com> |
14 +----------------------------------------------------------------------+
15 */
16
17 #include "php.h"
18
19 #include <string.h>
20
21 /*
22 * Returns 0 if both inputs match, non-zero if they don't.
23 * Returns -1 early if inputs do not have the same lengths.
24 *
25 */
php_safe_bcmp(const zend_string * a,const zend_string * b)26 PHPAPI int php_safe_bcmp(const zend_string *a, const zend_string *b)
27 {
28 const volatile unsigned char *ua = (const volatile unsigned char *)ZSTR_VAL(a);
29 const volatile unsigned char *ub = (const volatile unsigned char *)ZSTR_VAL(b);
30 size_t i = 0;
31 int r = 0;
32
33 if (ZSTR_LEN(a) != ZSTR_LEN(b)) {
34 return -1;
35 }
36
37 /* This is security sensitive code. Do not optimize this for speed. */
38 while (i < ZSTR_LEN(a)) {
39 r |= ua[i] ^ ub[i];
40 ++i;
41 }
42
43 return r;
44 }
45
