Şifreleyici Sınıfı

<?php
class Sifreleyici{
    private $_anahtar;
    public function __construct($anahtar = '', $md5 = true){
        $anahtar = str_split($md5 ? md5($anahtar) : sha1($anahtar), 1);
        $sinyal = false;
        $toplam = 0;
        foreach($anahtar as $karakter){
            if($sinyal){
                $toplam -= ord($karakter);
                $sinyal = false;
            }else{
                $toplam += ord($karakter);
                $sinyal = true;
            }
        }
        $this->_anahtar = abs($toplam);
    }
    public function sifrele($metin){
        $metin = str_split($metin, 1);
        $sonuc = '';
        foreach($metin as $karakter){
            $sonuc .= sprintf("%03x", ord($karakter) + $this->_anahtar);
        }
        return $sonuc;
    }
    public function coz($metin){
        $sonuc = '';
        $metin = str_split($metin, 3);
        foreach($metin as $karakter){
            $sonuc .= chr(hexdec($karakter) - $this->_anahtar);
        }
        return $sonuc;
    }
}
$anahtar = "asd";
$metin = "MerhabaDünya";
$s = new Sifreleyici($anahtar);
echo $es = $s->sifrele($metin);
echo "<br>";
echo $des = $s->coz($es);
?>
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