pragma solidity 0.5.11;

import "../../../interfaces/MinimalEscapeHatchRegistryInterface.sol";

/**

* @title AdharmaSmartWalletImplementation

* @author 0age

* @notice The Adharma smart wallet is an emergency implementation wallet that

* can be immediately upgraded to by the Upgrade Beacon Controller Manager in

* the event of a critical-severity exploit, or after a 90-day period of

* inactivity by Dharma. It gives the user direct, sole custody and control over

* their smart wallet until the Upgrade Beacon Controller Manager issues another

* upgrade to the implementation contract. If the user has set an escape hatch

* for the account, it will have authority over the smart wallet during the

* contingency - otherwise, the user signing key in storage slot zero will have

* that authority.

*/

contract AdharmaSmartWalletImplementation {

// The key is still held in storage slot zero.

address private _key;

// The escape hatch registry address is hard-coded as a constant.

MinimalEscapeHatchRegistryInterface private constant _ESCAPE_HATCH = (

MinimalEscapeHatchRegistryInterface(

0x00000000005280B515004B998a944630B6C663f8

)

);

// The smart wallet can receive funds, though it is inadvisable.

function () external payable {}

// Keep the initializer function on the contract in case a smart wallet has

// not yet been deployed but the account still contains funds.

function initialize(address key) external {

// Ensure that this function is only callable during contract construction.

assembly { if extcodesize(address) { revert(0, 0) } }

// Ensure that a key is set on this smart wallet.

require(key != address(0), "No key provided.");

// Set up the key.

_key = key;

}

// The escape hatch account, or the key account if no escape hatch is set, has

// sole authority to make calls from the smart wallet during the contingency.

function performCall(

address payable to, uint256 amount, bytes calldata data

) external payable returns (

bool ok, bytes memory returnData

) {

// Determine if an escape hatch is set on the registry for this account.

(bool escapeHatchSet, address escapeHatch) = _ESCAPE_HATCH.getEscapeHatch();

// Set escape hatch account as permitted caller, or user key if none is set.

address authority = escapeHatchSet ? escapeHatch : _key;

// Ensure that the call originates from the designated caller.

require(msg.sender == authority, "Caller prohibited.");

// Perform the call, forwarding all gas and supplying given value and data.

(ok, returnData) = to.call.value(amount)(data);

// Revert and pass along the revert reason if the call reverted.

require(ok, string(returnData));

}

}