Can I edit in the msg.sender value for the called contract?

Question

let's assume following solidity contracts:

 contract EntryPointContract {

    address one = '0x...';
    address two = '0x...';
    address delegateContract;

    constructor(address _delegateContract) {
        delegateContract = _delegateContract;
    }
 
    function test() public returns(bool) {

        (bool success,) = delegateContract.call(abi.encodeWithSignature("checkSender()"));
        return success
    }

}

contract DelegateContract {

    function checkSender() public {
        msgs = msg.sender;
    }
    
} 

Can I modify the EntryPointContract in some way that i will get address one value from EntryPointContract as msg.sender in DelegateContract ? Is it doable with assembly or opcodes for example or another way?

Answer 1

In Solidity, it is not possible to directly set msg.sender in the called contract (DelegateContract) to a specific address like address one from EntryPointContract. The msg.sender is determined by the caller of the contract, and it cannot be manipulated within the contract itself.

The msg.sender in DelegateContract will always be the address of the contract or external entity that calls the checkSender() function. You cannot change this behavior through assembly, opcodes, or any other means within the Solidity code.

If you need to pass specific information to DelegateContract that you want to be treated as the sender, you would need to pass it as an argument to a function in DelegateContract. For example:

contract EntryPointContract {
    address one = '0x...';
    address delegateContract;

    constructor(address _delegateContract) {
        delegateContract = _delegateContract;
    }
 
    function test() public returns(bool) {
        bool success = DelegateContract(delegateContract).checkSender(one);
        return success;
    }
}

contract DelegateContract {
    address public sender;

    function checkSender(address specificSender) public {
        sender = specificSender;
    }
}

In this modified example, the test() function of EntryPointContract explicitly passes the desired sender address (one) to the checkSender() function in DelegateContract.