<?php
/**
* Pure-PHP implementation of AES.
*
* Uses mcrypt, if available/possible, and an internal implementation, otherwise.
*
* PHP version 5
*
* NOTE: Since AES.php is (for compatibility and phpseclib-historical reasons) virtually
* just a wrapper to Rijndael.php you may consider using Rijndael.php instead of
* to save one include_once().
*
* If {@link self::setKeyLength() setKeyLength()} isn't called, it'll be calculated from
* {@link self::setKey() setKey()}. ie. if the key is 128-bits, the key length will be 128-bits. If it's 136-bits
* it'll be null-padded to 192-bits and 192 bits will be the key length until {@link self::setKey() setKey()}
* is called, again, at which point, it'll be recalculated.
*
* Since \phpseclib3\Crypt\AES extends \phpseclib3\Crypt\Rijndael, some functions are available to be called that, in the context of AES, don't
* make a whole lot of sense. {@link self::setBlockLength() setBlockLength()}, for instance. Calling that function,
* however possible, won't do anything (AES has a fixed block length whereas Rijndael has a variable one).
*
* Here's a short example of how to use this library:
* <code>
* <?php
* include 'vendor/autoload.php';
*
* $aes = new \phpseclib3\Crypt\AES('ctr');
*
* $aes->setKey('abcdefghijklmnop');
*
* $size = 10 * 1024;
* $plaintext = '';
* for ($i = 0; $i < $size; $i++) {
* $plaintext.= 'a';
* }
*
* echo $aes->decrypt($aes->encrypt($plaintext));
* ?>
* </code>
*
* @author Jim Wigginton <terrafrost@php.net>
* @copyright 2008 Jim Wigginton
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @link http://phpseclib.sourceforge.net
*/
namespace phpseclib3\Crypt;
/**
* Pure-PHP implementation of AES.
*
* @author Jim Wigginton <terrafrost@php.net>
*/
class AES extends Rijndael
{
/**
* Dummy function
*
* Since \phpseclib3\Crypt\AES extends \phpseclib3\Crypt\Rijndael, this function is, technically, available, but it doesn't do anything.
*
* @see \phpseclib3\Crypt\Rijndael::setBlockLength()
* @param int $length
* @throws \BadMethodCallException anytime it's called
*/
public function setBlockLength($length)
{
throw new \BadMethodCallException('The block length cannot be set for AES.');
}
/**
* Sets the key length
*
* Valid key lengths are 128, 192, and 256. Set the link to bool(false) to disable a fixed key length
*
* @see \phpseclib3\Crypt\Rijndael:setKeyLength()
* @param int $length
* @throws \LengthException if the key length isn't supported
*/
public function setKeyLength($length)
{
switch ($length) {
case 128:
case 192:
case 256:
break;
default:
throw new \LengthException('Key of size ' . $length . ' not supported by this algorithm. Only keys of sizes 128, 192 or 256 supported');
}
parent::setKeyLength($length);
}
/**
* Sets the key.
*
* Rijndael supports five different key lengths, AES only supports three.
*
* @see \phpseclib3\Crypt\Rijndael:setKey()
* @see setKeyLength()
* @param string $key
* @throws \LengthException if the key length isn't supported
*/
public function setKey($key)
{
switch (strlen($key)) {
case 16:
case 24:
case 32:
break;
default:
throw new \LengthException('Key of size ' . strlen($key) . ' not supported by this algorithm. Only keys of sizes 16, 24 or 32 supported');
}
parent::setKey($key);
}
}