Cisco Password Decrypter

<?php
function decrypt($pass) {
 $xarr = array (0x64, 0x73, 0x66, 0x64, 0x3b, 0x6b,
                0x66, 0x6f, 0x41, 0x2c, 0x2e, 0x69,
                0x79, 0x65, 0x77, 0x72, 0x6b, 0x6c,
                0x64, 0x4a, 0x4b, 0x44, 0x48, 0x53,
                0x55, 0x42);
 $z=0;
 $decrypted='';
 $unenc_lenght = (strlen($pass)-2)/2;
 $xorindex = (($pass[0]-0)*10)+($pass[1]-0);
 settype($xorindex, "integer");
 echo "Encrypted Password: <strong>".$pass."</strong><br />";

 for ($i = 2 ; $i <= strlen($pass); $i=$i+2) {
   $val=(hexdec($pass[$i])*16)+hexdec($pass[$i+1]);
   settype($val, "integer");
   $passdec[$z]=chr($val ^ $xarr[$xorindex]);
   $z++;
   $xorindex++;
 }

 for ($t=0;$t<=$unenc_lenght-1;$t++) {
   $decrypted .= $passdec[$t];
 }

 echo "Decrypted Password: <strong>".$decrypted." </strong>";
 return(1);
}
?>

<form action='<? $_SERVER['PHP_SELF']; ?>' method="post">
  <p>
   <input type="text" name="Password" size="40" />
   <input type="submit" name="Decrypt" value="Decrypt!" />
  </p>
 </form>
 <p>
<?
if ((isset($_POST[Decrypt])) and (strlen($_POST[Password])>0))
  decrypt($_POST[Password]);
 else
  echo " &nbsp; &nbsp; ";
?>