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<?php
/* vim: set expandtab tabstop=4 shiftwidth=4: */
// +----------------------------------------------------------------------+
// | PHP Version 4 |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2003 The PHP Group |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.0 of the PHP license, |
// | that is bundled with this package in the file LICENSE, and is |
// | available at through the world-wide-web at |
// | http://www.php.net/license/2_02.txt. |
// | If you did not receive a copy of the PHP license and are unable to |
// | obtain it through the world-wide-web, please send a note to |
// | license@php.net so we can mail you a copy immediately. |
// +----------------------------------------------------------------------+
// | Authors: Dave Mertens <dmertens@zyprexia.com> |
// +----------------------------------------------------------------------+
//
// $Id: Rc4.php,v 1.6 2003/10/04 16:39:32 zyprexia Exp $
/**
* RC4 stream cipher routines implementation
*
* in PHP4 based on code written by Damien Miller <djm@mindrot.org>
*
* Usage:
* $key = "pear";
* $message = "PEAR rulez!";
*
* $rc4 = new Crypt_RC4;
* $rc4->key($key);
* echo "Original message: $message <br>\n";
* $rc4->crypt($message);
* echo "Encrypted message: $message <br>\n";
* $rc4->decrypt($message);
* echo "Decrypted message: $message <br>\n";
*
* @version $Revision: 1.6 $
* @access public
* @package Crypt
* @author Dave Mertens <dmertens@zyprexia.com>
*/
class Crypt_RC4 {
/**
* Real programmers...
* @var array
*/
var $s= array();
/**
* Real programmers...
* @var array
*/
var $i= 0;
/**
* Real programmers...
* @var array
*/
var $j= 0;
/**
* Key holder
* @var string
*/
var $_key;
/**
* Constructor
* Pass encryption key to key()
*
* @see key()
* @param string key - Key which will be used for encryption
* @return void
* @access public
*/
function Crypt_RC4($key = null) {
if ($key != null) {
$this->setKey($key);
}
}
function setKey($key) {
if (strlen($key) > 0)
$this->_key = $key;
}
/**
* Assign encryption key to class
*
* @param string key - Key which will be used for encryption
* @return void
* @access public
*/
function key(&$key) {
$len= strlen($key);
for ($this->i = 0; $this->i < 256; $this->i++) {
$this->s[$this->i] = $this->i;
}
$this->j = 0;
for ($this->i = 0; $this->i < 256; $this->i++) {
$this->j = ($this->j + $this->s[$this->i] + ord($key[$this->i % $len])) % 256;
$t = $this->s[$this->i];
$this->s[$this->i] = $this->s[$this->j];
$this->s[$this->j] = $t;
}
$this->i = $this->j = 0;
}
/**
* Encrypt function
*
* @param string paramstr - string that will encrypted
* @return void
* @access public
*/
function crypt(&$paramstr) {
//Init key for every call, Bugfix 22316
$this->key($this->_key);
$len= strlen($paramstr);
for ($c= 0; $c < $len; $c++) {
$this->i = ($this->i + 1) % 256;
$this->j = ($this->j + $this->s[$this->i]) % 256;
$t = $this->s[$this->i];
$this->s[$this->i] = $this->s[$this->j];
$this->s[$this->j] = $t;
$t = ($this->s[$this->i] + $this->s[$this->j]) % 256;
$paramstr[$c] = chr(ord($paramstr[$c]) ^ $this->s[$t]);
}
}
/**
* Decrypt function
*
* @param string paramstr - string that will decrypted
* @return void
* @access public
*/
function decrypt(&$paramstr) {
//Decrypt is exactly the same as encrypting the string. Reuse (en)crypt code
$this->crypt($paramstr);
}
} //end of RC4 class
?>
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