PrivateBin/lib/filter.php

87 lines
1.9 KiB
PHP

<?php
/**
* ZeroBin
*
* a zero-knowledge paste bin
*
* @link http://sebsauvage.net/wiki/doku.php?id=php:zerobin
* @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
* @license http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
* @version 0.19
*/
/**
* filter
*
* Provides data filtering functions.
*/
class filter
{
/**
* strips slashes deeply
*
* @access public
* @static
* @param mixed $value
* @return mixed
*/
public static function stripslashes_deep($value)
{
return is_array($value) ?
array_map('filter::stripslashes_deep', $value) :
stripslashes($value);
}
/**
* format a given number of bytes
*
* @access public
* @static
* @param int $size
* @return string
*/
public static function size_humanreadable($size)
{
$iec = array('B', 'kiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB');
$i = 0;
while ( ( $size / 1024 ) >= 1 ) {
$size = $size / 1024;
$i++;
}
return number_format($size, ($i ? 2 : 0), '.', ' ') . ' ' . $iec[$i];
}
/**
* validate paste ID
*
* @access public
* @static
* @param string $dataid
* @return bool
*/
public static function is_valid_paste_id($dataid)
{
return (bool) preg_match('#\A[a-f\d]{16}\z#', $dataid);
}
/**
* fixed time string comparison operation to prevent timing attacks
* https://crackstation.net/hashing-security.htm?=rd#slowequals
*
* @access public
* @static
* @param string $a
* @param string $b
* @return bool
*/
public static function slow_equals($a, $b)
{
$diff = strlen($a) ^ strlen($b);
for($i = 0; $i < strlen($a) && $i < strlen($b); $i++)
{
$diff |= ord($a[$i]) ^ ord($b[$i]);
}
return $diff === 0;
}
}