/**
* rc4加密算法,解密方法直接再一次加密就是解密
* @param [type] $data 要加密的数据
* @param [type] $pwd 加密使用的key
* @return [type] [description]
*/
function rc4($data, $pwd) {
$key[] = "";
$box[] = "";
$pwd_length = strlen($pwd);
$data_length = strlen($data);
$cipher = '';
for ($i = 0; $i < 256; $i++) {
$key[$i] = ord($pwd[$i % $pwd_length]);
$box[$i] = $i;
}
for ($j = $i = 0; $i < 256; $i++) {
$j = ($j + $box[$i] + $key[$i]) % 256;
$tmp = $box[$i];
$box[$i] = $box[$j];
$box[$j] = $tmp;
}
for ($a = $j = $i = 0; $i < $data_length; $i++) {
$a = ($a + 1) % 256;
$j = ($j + $box[$a]) % 256;
$tmp = $box[$a];
$box[$a] = $box[$j];
$box[$j] = $tmp;
$k = $box[(($box[$a] + $box[$j]) % 256)];
$cipher .= chr(ord($data[$i]) ^ $k);
}
return $cipher;
}
echo "=======================\r\n";
$msgkey = md5('89n3kb5bj9h3gz2');
$enstr = base64_encode(rc4('zhaokeli.com', $msgkey));
echo "rc4-enstr:{$enstr}\r\n";
$destr = rc4(base64_decode($enstr), $msgkey);
echo "rc4-destr:{$destr}\r\n";
?>
