// SPDX-License-Identifier: MIT pragma solidity =0.8.24; import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol"; import {IERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol"; import {SafeERC20Upgradeable} from "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol"; import {ITokenMessenger} from "../../../interfaces/ITokenMessenger.sol"; import {IL1ERC20Gateway} from "../../../L1/gateways/IL1ERC20Gateway.sol"; import {IL2ScrollMessenger} from "../../IL2ScrollMessenger.sol"; import {IL2ERC20Gateway} from "../IL2ERC20Gateway.sol"; import {CCTPGatewayBase} from "../../../libraries/gateway/CCTPGatewayBase.sol"; import {ScrollGatewayBase} from "../../../libraries/gateway/ScrollGatewayBase.sol"; import {L2ERC20Gateway} from "../L2ERC20Gateway.sol"; /// @title L2USDCGatewayCCTP /// @notice The `L2USDCGatewayCCTP` contract is used to withdraw `USDC` token in layer 2 and /// finalize deposit `USDC` from layer 1. contract L2USDCGatewayCCTP is CCTPGatewayBase, L2ERC20Gateway { using SafeERC20Upgradeable for IERC20Upgradeable; /*************** * Constructor * ***************/ constructor( address _l1USDC, address _l2USDC, uint32 _destinationDomain, address _counterpart, address _router, address _messenger ) CCTPGatewayBase(_l1USDC, _l2USDC, _destinationDomain) ScrollGatewayBase(_counterpart, _router, _messenger) { if (_router == address(0)) revert ErrorZeroAddress(); _disableInitializers(); } /// @notice Initialize the storage of L2USDCGatewayCCTP. /// /// @dev The parameters `_counterpart`, `_router`, `_messenger` are no longer used. /// /// @param _counterpart The address of L1USDCGatewayCCTP in L1. /// @param _router The address of L2GatewayRouter. /// @param _messenger The address of L2ScrollMessenger. /// @param _cctpMessenger The address of TokenMessenger in local domain. /// @param _cctpTransmitter The address of MessageTransmitter in local domain. function initialize( address _counterpart, address _router, address _messenger, address _cctpMessenger, address _cctpTransmitter ) external initializer { ScrollGatewayBase._initialize(_counterpart, _router, _messenger); CCTPGatewayBase._initialize(_cctpMessenger, _cctpTransmitter); } /************************* * Public View Functions * *************************/ /// @inheritdoc IL2ERC20Gateway function getL1ERC20Address(address) external view override returns (address) { return l1USDC; } /// @inheritdoc IL2ERC20Gateway function getL2ERC20Address(address) public view override returns (address) { return l2USDC; } /***************************** * Public Mutating Functions * *****************************/ /// @inheritdoc IL2ERC20Gateway /// @dev The function will not mint the USDC, users need to call `claimUSDC` after this function is done. function finalizeDepositERC20( address _l1Token, address _l2Token, address _from, address _to, uint256 _amount, bytes memory _data ) external payable override onlyCallByCounterpart { require(msg.value == 0, "nonzero msg.value"); require(_l1Token == l1USDC, "l1 token not USDC"); require(_l2Token == l2USDC, "l2 token not USDC"); uint256 _nonce; (_nonce, _data) = abi.decode(_data, (uint256, bytes)); require(status[_nonce] == CCTPMessageStatus.None, "message relayed"); status[_nonce] = CCTPMessageStatus.Pending; emit FinalizeDepositERC20(_l1Token, _l2Token, _from, _to, _amount, _data); } /******************************* * Public Restricted Functions * *******************************/ /// @notice Update the CCTP contract addresses. /// @param _messenger The address of TokenMessenger in local domain. /// @param _transmitter The address of MessageTransmitter in local domain. function updateCCTPContracts(address _messenger, address _transmitter) external onlyOwner { cctpMessenger = _messenger; cctpTransmitter = _transmitter; } /********************** * Internal Functions * **********************/ /// @inheritdoc L2ERC20Gateway function _withdraw( address _token, address _to, uint256 _amount, bytes memory _data, uint256 _gasLimit ) internal virtual override { require(_amount > 0, "withdraw zero amount"); require(_token == l2USDC, "only USDC is allowed"); // 1. Extract real sender if this call is from L1GatewayRouter. address _from = _msgSender(); if (router == _from) { (_from, _data) = abi.decode(_data, (address, bytes)); } // 2. Transfer token into this contract. IERC20Upgradeable(_token).safeTransferFrom(_from, address(this), _amount); // 3. Burn token through CCTP TokenMessenger uint256 _nonce = ITokenMessenger(cctpMessenger).depositForBurnWithCaller( _amount, destinationDomain, bytes32(uint256(uint160(_to))), address(this), bytes32(uint256(uint160(counterpart))) ); // 4. Generate message passed to L1USDCGateway. address _l1USDC = l1USDC; bytes memory _message = abi.encodeWithSelector( IL1ERC20Gateway.finalizeWithdrawERC20.selector, _l1USDC, _token, _from, _to, _amount, abi.encode(_nonce, _data) ); // 4. Send message to L1ScrollMessenger. IL2ScrollMessenger(messenger).sendMessage{value: msg.value}(counterpart, 0, _message, _gasLimit); emit WithdrawERC20(_l1USDC, _token, _from, _to, _amount, _data); } }