PrivateBin/lib/Filter.php

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<?php
/**
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* PrivateBin
*
* a zero-knowledge paste bin
*
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* @link https://github.com/PrivateBin/PrivateBin
* @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
* @license https://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
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* @version 1.2
*/
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namespace PrivateBin;
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use Exception;
/**
* Filter
*
* Provides data filtering functions.
*/
class Filter
{
/**
* format a given time string into a human readable label (localized)
*
* accepts times in the format "[integer][time unit]"
*
* @access public
* @static
* @param string $time
* @throws Exception
* @return string
*/
public static function formatHumanReadableTime($time)
{
if (preg_match('/^(\d+) *(\w+)$/', $time, $matches) !== 1) {
throw new Exception("Error parsing time format '$time'", 30);
}
switch ($matches[2]) {
case 'sec':
$unit = 'second';
break;
case 'min':
$unit = 'minute';
break;
default:
$unit = rtrim($matches[2], 's');
}
return I18n::_(array('%d ' . $unit, '%d ' . $unit . 's'), (int) $matches[1]);
}
/**
* format a given number of bytes in IEC 80000-13:2008 notation (localized)
*
* @access public
* @static
* @param int $size
* @return string
*/
public static function formatHumanReadableSize($size)
{
$iec = array('B', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB');
$i = 0;
while (($size / 1024) >= 1) {
$size = $size / 1024;
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++$i;
}
return number_format($size, ($i ? 2 : 0), '.', ' ') . ' ' . I18n::_($iec[$i]);
}
/**
* 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 $b
* @return bool
*/
public static function slowEquals($a, $b)
{
$diff = strlen($a) ^ strlen($b);
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for ($i = 0; $i < strlen($a) && $i < strlen($b); ++$i) {
$diff |= ord($a[$i]) ^ ord($b[$i]);
}
return $diff === 0;
}
}