class _setcookie{
	//加密函数(参数:数组，返回值:字符串)
	public static $key_t = "sjiofssdsfd";//设置加密种子
	public static function encrypt($cookie_array){
		$txt = serialize($cookie_array);
		srand();//生成随机数
		$encrypt_key = md5(rand(0,10000));//从0到10000取一个随机数
		$ctr = 0;
		$tmp = '';
		for($i = 0;$i < strlen($txt);$i++){
			$ctr = $ctr == strlen($encrypt_key) ? 0 : $ctr;
			$tmp .= $encrypt_key[$ctr].($txt[$i] ^ $encrypt_key[$ctr++]);
		}
		return base64_encode(_setcookie::key($tmp,_setcookie::$key_t));
	}
	
	//解密函数(参数:字符串，返回值:数组)
	public static function decrypt($txt){
		$txt = _setcookie::key(base64_decode($txt), _setcookie::$key_t);
		$tmp = '';
		for($i = 0;$i < strlen($txt); $i++) {
			$md5 = $txt[$i];
			$tmp .= $txt[++$i] ^ $md5;
		}
		$tmp_t = unserialize($tmp);
		return $tmp_t;
	}
	
	public static function key($txt,$encrypt_key){
		$encrypt_key = md5($encrypt_key);
		$ctr = 0;
		$tmp = '';
		for($i = 0; $i < strlen($txt); $i++) {
			$ctr = $ctr == strlen($encrypt_key) ? 0 : $ctr;
			$tmp .= $txt[$i] ^ $encrypt_key[$ctr++];
		}
		return $tmp;
	}
}

$test=array(
		"realname" => "小明",
		"username" => "xiaoming",
		"groupid" => "1",
		"password" => "a23bsdfsdfsdf",
		"lastlogindate"=> "2013-11-01",
		"lastloginIP" => "10.1.1.159"
		);
$en_a=_setcookie::encrypt($test);
//打印加密后的字符串
echo $en_a;
echo "<br/>";

$test_base64 = base64_decode($en_a);
//打印用base64解密后的字符串，测试用
echo $test_base64;
echo "<br/>";

$de_a=_setcookie::decrypt($en_a);
//打印解密后的字符串
print_r($de_a);