PHP Token(令牌)设计应用

转自：http://my.oschina.net/u/912810/blog/358973

<?php
class GEncrypt {
    protected static function keyED($txt,$encrypt_key){
        $encrypt_key = md5($encrypt_key);
        $ctr=0;
        $tmp = "";
        for ($i=0;$i<strlen($txt);$i++){
            if ($ctr==strlen($encrypt_key)) $ctr=0;
            $tmp.= substr($txt,$i,1) ^ substr($encrypt_key,$ctr,1);
            $ctr++;
        }
        return $tmp;
    } 

    public static function encrypt($txt,$key){
        //$encrypt_key = md5(rand(0,32000));
        $encrypt_key = md5(((float) date("YmdHis") + rand(10000000000000000,99999999999999999)).rand(100000,999999));
        $ctr=0;
        $tmp = "";
        for ($i=0;$i<strlen($txt);$i++){
            if ($ctr==strlen($encrypt_key)) $ctr=0;
            $tmp.= substr($encrypt_key,$ctr,1) . (substr($txt,$i,1) ^ substr($encrypt_key,$ctr,1));
            $ctr++;
        }
        return base64_encode(self::keyED($tmp,$key));
    } 

    public static function decrypt($txt,$key){
        $txt = self::keyED( base64_decode($txt),$key);
        $tmp = "";
        for ($i=0;$i<strlen($txt);$i++){
            $md5 = substr($txt,$i,1);
            $i++;
            $tmp.= (substr($txt,$i,1) ^ $md5);
        }
        return $tmp;
    }
}
?> 

完毕。