<?php
class Crypt_Rc4 {
var $s= array();
var $i= 0;
var $j= 0;
var $_key;
function Crypt_RC4($key = null) {
if ($key != null) {
$this->setKey($key);
}
}
function setKey($key) {
if (strlen($key) > 0)
$this->_key = $key;
}
function key(&$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 = $this->j = 0;
}
function crypt(&$paramstr) {
$this->key($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]);
}
}
function decrypt(&$paramstr) {
$this->crypt($paramstr);
}
}
?>
