<?php
function String2Hex($string){
$hex='';
for ($i=0; $i < strlen($string); $i++){
    $hex .= dechex(ord($string[$i]));
}
return $hex;

function Hex2String($hex){
$string='';
for ($i=0; $i < strlen($hex)-1; $i+=2){
    $string .= chr(hexdec($hex[$i].$hex[$i+1]));
}
return $string;
}

function PKCS5AddPadding($input) {
    $pad = strlen($input) % 16;
    for ($i = $pad; $i < 16; $i++) {
        $input .= chr(16 - $pad);
    }
    return $input;
}
function PKCS5RemovePadding($input) {
    return rtrim($input, substr($input, strlen($input) - 1, 1));
}

function kn_dec($ciph,$key) {
$cipherText = base64_decode($ciph);
$plainText = PKCS5RemovePadding(mcrypt_decrypt(MCRYPT_RIJNDAEL_128,$key, $cipherText, MCRYPT_MODE_CBC));
return $plainText;
}

function kn_enc($plai,$key) {
$plainText = $plai;
$cipherText = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, PKCS5AddPadding($plainText), MCRYPT_MODE_CBC);
 $cipherText = base64_encode($cipherText);

 return $cipherText;
}




if (isset($_POST['te'])) {

 die(String2Hex(kn_enc($_POST['te'],'!(*@&#^$%!&%^&*@')));

} else if (isset($_POST['td'])) {
die(kn_dec(Hex2String($_POST['td']),'!(*@&#^$%!&%^&*@'));
}



?>