libraries/hash.lib.php

   1 <?php
   2 /* vim: set expandtab sw=4 ts=4 sts=4: */
   3 /**
   4  * The hash extension polyfills.
   5  *
   6  * @package PhpMyAdmin
   7  */
   8
   9 if (! defined('PHPMYADMIN')) {
  10     exit;
  11 }
  12
  13 /* Compatibility with PHP < 5.6 */
  14 if (! function_exists('hash_equals')) {
  15     /**
  16      * Timing attack safe string comparison
  17      *
  18      * @param string $a first string
  19      * @param string $b second string
  20      *
  21      * @return boolean whether they are equal
  22      */
  23     function hash_equals($a, $b) {
  24         $ret = strlen($a) ^ strlen($b);
  25         $ret |= array_sum(unpack("C*", $a ^ $b));
  26         return ! $ret;
  27     }
  28 }