<?
/* 
 * encryption and decryption algorythm class
 * for use in any database
 * 
 * use hash of 10 characters and XOR comparison with password
 * to convert ASCII to DEC to HEX
 * and back again
 * 
 * change hash 
 * AJR Nov 3, 2003
 *
 */
 
 class EncDec{
    
    var $hash;
	
    function hexToInt($s, $i)
    {

        (int)$j = $i * 2;
        (string)$s1 = $s;
        (string)$c = substr($s1, $j, 1);  // get the char at position $j, length 1 
        (string)$c1 = substr($s1, $j+1, 1); // get the char at postion $j + 1, length 1
        (int)$k = 0;
	
	switch ($c)
		{

		case "A":
		$k += 160;
		break;

		case "B":
        	$k += 176;
        	break;

		case "C":
       		$k += 192;
        	break;

		case "D":
        	$k += 208;
        	break;

		case "E":
        	$k += 224;
        	break;

		case "F":
        	$k += 240;
        	break;

		case " ":
		$k += 0;
		break;

		default:
	
		(int)$k = $k + (16 * (int)$c);
		break;
		}
        
	switch ($c1)
		{
	
		case "A":
		$k += 10;
		break;

		case "B":
        	$k += 11;
        	break;

		case "C":
        	$k += 12;
        	break;

		case "D":
        	$k += 13;
        	break;

		case "E":
        	$k += 14;
        	break;

		case "F":
        	$k += 15;
        	break;

		case " ":
		$k += 0;
        	break;

		default:

       		$k += (int)$c1;    
		break;
		}
        
	return $k;
    }

    function hexToIntArray($s)
    {
        (string)$s1 = $s;
        (int)$i = strlen($s1);
        (int)$j = $i / 2;
        for($l = 0; $l < $j; $l++)
        {
            (int)$k = $this->hexToInt($s1,$l);
	    $ai[$l] = $k;
	}

        return $ai;
    }

    function charToInt($c)
    {
        $ac[0] = $c;
    	return $ac;
    }

    function xorString($ai)
    {
        $s = $this->hash; // 
        (int)$i = strlen($s);
        $ai1 = $ai;
        (int)$j = count($ai1);
        for($i = 0; $i < $j; $i = strlen($s))
            $s = $s.$s;

        for($k = 0; $k < $j; $k++)
        {
            (string)$c = substr($s,$k,1);
	    $ac[$k] = chr($ai1[$k] ^ ord($c));
	}

        (string)$s1 = implode('', $ac);
        return $s1;
    }

    function phpDecrypt($s)
    {
        {
            $ai = $this->hexToIntArray($s);
	    (string)$s1 = $this->xorString($ai);
	    return $s1;
        }
    }

    function intToHex($i)
    {
        (int)$j = (int)$i / 16;
        if ((int)$j == 0) {
            (string)$s = " ";
	}
        else
	{
	   (string)$s = strtoupper(dechex($j));
        }   
        (int)$k = (int)$i - (int)$j * 16;
        (string)$s = $s.strtoupper(dechex($k));

	return $s;	
    }

    function xorCharString($s)
    {
        $ac = preg_split('//', $s, -1, PREG_SPLIT_NO_EMPTY);
        (string)$s1 = $this->hash;
        (int)$i = strlen($s1); 
        (int)$j = count($ac); 
        for($i=0; $i < $j; $i = strlen($s1))
        {
	    $s1 = $s1.$s1;
	}

        for($k = 0; $k < $j; $k++)
        {
	    $c = substr($s1,$k,1);
	    $ai[$k] = ord($c) ^ ord($ac[$k]);
        }

        return $ai;
    }

    function phpEncrypt($s)
    {
        $ai = $this->xorCharString($s);
	$s1 = "";
        for($i = 0; $i < count($ai); $i++)
            $s1 = $s1.$this->intToHex((int)$ai[$i]);
        return $s1;
    }

} 
/* 
 *
 * end of class declaration
 *
 *
 */
?>