ControlledDelegatecall.sol

/* Bad */
contract Bad {
	function badDelegate(address _yourContract, bytes calldata _data) payable public returns (bytes memory) {
	    (bool success, bytes memory data) =  _yourContract.delegatecall(_data);
	    require(success);
	    return data;
	}
}
/* Vulnerability
Anyone can destroy the Bad contract using by “selfdestruct” 
because in the context of delegatecall, 
msg.sender will be BadContract even the caller is anyone.
*/

/* Better */
contract Good {
	mapping(address => bool) whitelist; //add
	function goodDelegate(address _yourContract, bytes calldata _data) payable public returns (bytes memory) {
       	    require(whitelist[msg.sender]); //add
	    (bool success, bytes memory data) =  _yourContract.delegatecall(_data);
	    require(success);
	    return data;
	}
}