fwPack/fwUnpack in php?

[shaosean at unitz.ca]

well here are the two functions.. next ;-)

-Sean


<%

function fwPack($pData, $pPassword="") {
  if ($pPassword === ""):
    $pData = "00" . gzencode($pData);

  else:
    $tKeyString = pack("H*", md5($pPassword));
    $tKeyStringLen = strlen($tKeyString);

    $pData = gzencode($pData);
    $tDataLen = strlen($pData);

    $tCryptoText = "";
    $i = 0;
    for ($k=0; $k < $tDataLen; $k++):
      if ($i >= $tKeyStringLen):
        $i = 0;
      endif;
      $tCryptoText .= chr( ord($pData{$k}) ^ ord($tKeyString{$i}) );
      $i++;
    endfor;
    $pData = "01" . $tCryptoText;
  endif;
  return base64_encode($pData);
}
// end fwPack


function fwUnpack($pData, $pPassword="") {
  $pData = base64_decode($pData);
  $tEncryptionMethod = $pData{0} . $pData{1};   // get the encryption 
method
  $pData = substr($pData,2);    // remove the encryption method from the 
data

  switch($tEncryptionMethod):
  case "00":   // no encryption
    break;
  case "01":   // md5 encryption
    $tKeyString = pack("H*", md5($pPassword));
    $tKeyStringLen = strlen($tKeyString);

    $tDataLen = strlen($pData);

    $tClearText = "";
    $i = 0;
    for ($k=0; $k < $tDataLen; $k++):
      if ($i >= $tKeyStringLen):
        $i = 0;
      endif;
      $tClearText .= chr( ord($pData{$k}) ^ ord($tKeyString{$i}) );
      $i++;
    endfor;
    $pData = $tClearText;
  endswitch;

  return gzinflate(substr($pData,10)); 
}
// end fwUnpack


echo fwUnpack(fwPack("abraxas", "fred"), "fred");

%>