Smr 1935 erc20 withdraw l1

script/DeployRootContracts.s.sol

@@ -21,6 +21,7 @@ contract DeployRootContracts is Script {
         uint256 rootPrivateKey = vm.envUint("ROOT_PRIVATE_KEY");
         string memory rootRpcUrl = vm.envString("ROOT_RPC_URL");
         string memory deployEnvironment = vm.envString("ENVIRONMENT");
+        address rootGateway = vm.envAddress("ROOT_GATEWAY_ADDRESS");
 
         /**
          * DEPLOY ROOT CHAIN CONTRACTS
@@ -36,18 +37,17 @@ contract DeployRootContracts is Script {
 
         RootERC20Bridge rootERC20BridgeImplementation = new RootERC20Bridge();
         rootERC20BridgeImplementation.initialize(
-            address(1), address(1), "filler", address(1), address(1), address(1), 1
+            address(1), address(1), "filler", address(1), address(1), address(1), "filler_child_name", 1
         );
         TransparentUpgradeableProxy rootERC20BridgeProxy = new TransparentUpgradeableProxy(
             address(rootERC20BridgeImplementation),
             address(proxyAdmin),
             ""
         );
 
-        RootAxelarBridgeAdaptor rootBridgeAdaptorImplementation = new RootAxelarBridgeAdaptor();
-        rootBridgeAdaptorImplementation.initialize(
-            address(rootERC20BridgeImplementation), "Filler", address(1), address(1)
-        );
+        RootAxelarBridgeAdaptor rootBridgeAdaptorImplementation = new RootAxelarBridgeAdaptor(rootGateway);
+        rootBridgeAdaptorImplementation.initialize(address(rootERC20BridgeImplementation), "Filler", address(1));
+
         TransparentUpgradeableProxy rootBridgeAdaptorProxy = new TransparentUpgradeableProxy(
             address(rootBridgeAdaptorImplementation),
             address(proxyAdmin),

script/InitializeRootContracts.s.sol

@@ -24,7 +24,6 @@ struct InitializeRootContractsParams {
     address rootIMXToken;
     address rootWETHToken;
     string childChainName;
-    address rootGateway;
     address rootGasService;
     uint256 initialIMXCumulativeDepositLimit;
 }
@@ -42,7 +41,6 @@ contract InitializeRootContracts is Script {
             rootIMXToken: vm.envAddress("ROOT_IMX_ADDRESS"),
             rootWETHToken: vm.envAddress("ROOT_WETH_ADDRESS"),
             childChainName: vm.envString("CHILD_CHAIN_NAME"),
-            rootGateway: vm.envAddress("ROOT_GATEWAY_ADDRESS"),
             rootGasService: vm.envAddress("ROOT_GAS_SERVICE_ADDRESS"),
             initialIMXCumulativeDepositLimit: vm.envUint("INITIAL_IMX_CUMULATIVE_DEPOSIT_LIMIT")
         });
@@ -63,13 +61,13 @@ contract InitializeRootContracts is Script {
             params.rootChainChildTokenTemplate,
             params.rootIMXToken,
             params.rootWETHToken,
+            params.childChainName,
             params.initialIMXCumulativeDepositLimit
         );
 
         params.rootBridgeAdaptor.initialize(
             address(params.rootERC20Bridge), // root bridge
             params.childChainName, // child chain name
-            params.rootGateway, // axelar gateway
             params.rootGasService // axelar gas service
         );
 

src/child/ChildAxelarBridgeAdaptor.sol

@@ -22,7 +22,6 @@ contract ChildAxelarBridgeAdaptor is
     /// @notice Address of bridge to relay messages to.
     IChildERC20Bridge public childBridge;
     IAxelarGasService public gasService;
-    string public rootBridgeAdaptor;
     string public rootChain;
 
     constructor(address _gateway) AxelarExecutable(_gateway) {}
@@ -39,7 +38,6 @@ contract ChildAxelarBridgeAdaptor is
         childBridge = IChildERC20Bridge(_childBridge);
         rootChain = _rootChain;
         gasService = IAxelarGasService(_gasService);
-        rootBridgeAdaptor = childBridge.rootERC20BridgeAdaptor();
     }
 
     /**
@@ -54,7 +52,7 @@ contract ChildAxelarBridgeAdaptor is
         }
 
         // Load from storage.
-        string memory _rootBridgeAdaptor = rootBridgeAdaptor;
+        string memory _rootBridgeAdaptor = childBridge.rootERC20BridgeAdaptor();
         string memory _rootChain = rootChain;
 
         gasService.payNativeGasForContractCall{value: msg.value}(

src/interfaces/root/IRootERC20Bridge.sol

@@ -5,6 +5,14 @@ import {IERC20Metadata} from "@openzeppelin/contracts/token/ERC20/extensions/IER
 
 interface IRootERC20Bridge {
     function childBridgeAdaptor() external view returns (string memory);
+    /**
+     * @notice Receives a bridge message from child chain, parsing the message type then executing.
+     * @param sourceChain The chain the message originated from.
+     * @param sourceAddress The address the message originated from.
+     * @param data The data payload of the message.
+     */
+    function onMessageReceive(string calldata sourceChain, string calldata sourceAddress, bytes calldata data)
+        external;
 
     /**
      * @notice Initiate sending a mapToken message to the child chain.
@@ -64,6 +72,14 @@ interface IRootERC20BridgeEvents {
         address indexed receiver,
         uint256 amount
     );
+
+    event RootChainERC20Withdraw(
+        address indexed rootToken,
+        address indexed childToken,
+        address withdrawer,
+        address indexed receiver,
+        uint256 amount
+    );
 }
 
 interface IRootERC20BridgeErrors {
@@ -73,6 +89,8 @@ interface IRootERC20BridgeErrors {
     error ZeroAmount();
     /// @notice Error when a zero address is given when not valid.
     error ZeroAddress();
+    /// @notice Error when the child chain name is invalid.
+    error InvalidChildChain();
     /// @notice Error when a token is already mapped.
     error AlreadyMapped();
     /// @notice Error when a token is not mapped when it should be.
@@ -87,6 +105,14 @@ interface IRootERC20BridgeErrors {
     error BalanceInvariantCheckFailed(uint256 actualBalance, uint256 expectedBalance);
     /// @notice Error when the given child chain bridge adaptor is invalid.
     error InvalidChildERC20BridgeAdaptor();
+    /// @notice Error when a message received has invalid data.
+    error InvalidData();
+    /// @notice Error when a message received has invalid source address.
+    error InvalidSourceAddress();
+    /// @notice Error when a message received has invalid source chain.
+    error InvalidSourceChain();
+    /// @notice Error when caller is not the root bridge adaptor but should be.
+    error NotBridgeAdaptor();
     /// @notice Error when the total IMX deposit limit is exceeded
     error ImxDepositLimitExceeded();
     /// @notice Error when the IMX deposit limit is set below the amount of IMX already deposited

src/root/RootAxelarBridgeAdaptor.sol

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: Apache 2.0
 pragma solidity ^0.8.21;
 
+import {AxelarExecutable} from "@axelar-gmp-sdk-solidity/contracts/executable/AxelarExecutable.sol";
 import {Initializable} from "@openzeppelin/contracts/proxy/utils/Initializable.sol";
 import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import {IERC20Metadata} from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
@@ -20,41 +21,38 @@ import {IRootERC20Bridge} from "../interfaces/root/IRootERC20Bridge.sol";
  * @notice RootAxelarBridgeAdaptor is a bridge adaptor that allows the RootERC20Bridge to communicate with the Axelar Gateway.
  */
 contract RootAxelarBridgeAdaptor is
+    AxelarExecutable,
     Initializable,
     IRootERC20BridgeAdaptor,
     IRootAxelarBridgeAdaptorEvents,
     IRootAxelarBridgeAdaptorErrors
 {
     using SafeERC20 for IERC20Metadata;
 
-    address public rootBridge;
+    IRootERC20Bridge public rootBridge;
     string public childBridgeAdaptor;
     string public childChain;
-    IAxelarGateway public axelarGateway;
     IAxelarGasService public gasService;
     mapping(uint256 => string) public chainIdToChainName;
 
+    constructor(address _gateway) AxelarExecutable(_gateway) {}
+
     /**
      * @notice Initilization function for RootAxelarBridgeAdaptor.
      * @param _rootBridge Address of root bridge contract.
      * @param _childChain Name of child chain.
-     * @param _axelarGateway Address of Axelar Gateway contract.
      * @param _gasService Address of Axelar Gas Service contract.
      */
-    function initialize(address _rootBridge, string memory _childChain, address _axelarGateway, address _gasService)
-        public
-        initializer
-    {
-        if (_rootBridge == address(0) || _axelarGateway == address(0) || _gasService == address(0)) {
+    function initialize(address _rootBridge, string memory _childChain, address _gasService) public initializer {
+        if (_rootBridge == address(0) || _gasService == address(0)) {
             revert ZeroAddresses();
         }
 
         if (bytes(_childChain).length == 0) {
             revert InvalidChildChain();
         }
-        rootBridge = _rootBridge;
+        rootBridge = IRootERC20Bridge(_rootBridge);
         childChain = _childChain;
-        axelarGateway = IAxelarGateway(_axelarGateway);
         gasService = IAxelarGasService(_gasService);
     }
 
@@ -66,7 +64,7 @@ contract RootAxelarBridgeAdaptor is
         if (msg.value == 0) {
             revert NoGas();
         }
-        if (msg.sender != rootBridge) {
+        if (msg.sender != address(rootBridge)) {
             revert CallerNotBridge();
         }
 
@@ -79,7 +77,17 @@ contract RootAxelarBridgeAdaptor is
             address(this), _childChain, _childBridgeAdaptor, payload, refundRecipient
         );
 
-        axelarGateway.callContract(_childChain, _childBridgeAdaptor, payload);
+        gateway.callContract(_childChain, _childBridgeAdaptor, payload);
         emit AxelarMessage(_childChain, _childBridgeAdaptor, payload);
     }
+
+    /**
+     * @dev This function is called by the parent `AxelarExecutable` contract to execute the payload.
+     */
+    function _execute(string calldata sourceChain_, string calldata sourceAddress_, bytes calldata payload_)
+        internal
+        override
+    {
+        rootBridge.onMessageReceive(sourceChain_, sourceAddress_, payload_);
+    }
 }

src/root/RootERC20Bridge.sol

@@ -7,6 +7,7 @@ import {Clones} from "@openzeppelin/contracts/proxy/Clones.sol";
 import {Address} from "@openzeppelin/contracts/utils/Address.sol";
 import {Strings} from "@openzeppelin/contracts/utils/Strings.sol";
 import {Ownable2Step} from "@openzeppelin/contracts/access/Ownable2Step.sol";
+import {Address} from "@openzeppelin/contracts/utils/Address.sol";
 import {IAxelarGateway} from "@axelar-cgp-solidity/contracts/interfaces/IAxelarGateway.sol";
 import {IRootERC20Bridge, IERC20Metadata} from "../interfaces/root/IRootERC20Bridge.sol";
 import {IRootERC20BridgeEvents, IRootERC20BridgeErrors} from "../interfaces/root/IRootERC20Bridge.sol";
@@ -38,6 +39,7 @@ contract RootERC20Bridge is
     uint256 public constant NO_DEPOSIT_LIMIT = 0;
     bytes32 public constant MAP_TOKEN_SIG = keccak256("MAP_TOKEN");
     bytes32 public constant DEPOSIT_SIG = keccak256("DEPOSIT");
+    bytes32 public constant WITHDRAW_SIG = keccak256("WITHDRAW");
     address public constant NATIVE_ETH = address(0xeee);
 
     IRootERC20BridgeAdaptor public rootBridgeAdaptor;
@@ -53,6 +55,8 @@ contract RootERC20Bridge is
     address public childETHToken;
     /// @dev The address of the wETH ERC20 token on L1.
     address public rootWETHToken;
+    /// @dev The name of the chain that this bridge is connected to.
+    string public childChain;
     /// @dev The maximum cumulative amount of IMX that can be deposited into the bridge.
     /// @dev A limit of zero indicates unlimited.
     uint256 public imxCumulativeDepositLimit;
@@ -65,6 +69,7 @@ contract RootERC20Bridge is
      * @param newChildTokenTemplate Address of child token template to clone.
      * @param newRootIMXToken Address of ERC20 IMX on the root chain.
      * @param newRootWETHToken Address of ERC20 WETH on the root chain.
+     * @param newChildChain Name of child chain.
      * @param newImxCumulativeDepositLimit The cumulative IMX deposit limit.
      * @dev Can only be called once.
      */
@@ -75,6 +80,7 @@ contract RootERC20Bridge is
         address newChildTokenTemplate,
         address newRootIMXToken,
         address newRootWETHToken,
+        string memory newChildChain,
         uint256 newImxCumulativeDepositLimit
     ) public initializer {
         if (
@@ -86,6 +92,10 @@ contract RootERC20Bridge is
         if (bytes(newChildBridgeAdaptor).length == 0) {
             revert InvalidChildERC20BridgeAdaptor();
         }
+        if (bytes(newChildChain).length == 0) {
+            revert InvalidChildChain();
+        }
+
         childERC20Bridge = newChildERC20Bridge;
         childTokenTemplate = newChildTokenTemplate;
         rootIMXToken = newRootIMXToken;
@@ -95,6 +105,7 @@ contract RootERC20Bridge is
         );
         rootBridgeAdaptor = IRootERC20BridgeAdaptor(newRootBridgeAdaptor);
         childBridgeAdaptor = newChildBridgeAdaptor;
+        childChain = newChildChain;
         imxCumulativeDepositLimit = newImxCumulativeDepositLimit;
     }
 
@@ -135,6 +146,35 @@ contract RootERC20Bridge is
      */
     receive() external payable {}
 
+    /**
+     * @inheritdoc IRootERC20Bridge
+     * @dev This is only callable by the root chain bridge adaptor.
+     * @dev Validates `sourceAddress` is the child chain's bridgeAdaptor.
+     */
+    function onMessageReceive(string calldata messageSourceChain, string calldata sourceAddress, bytes calldata data)
+        external
+        override
+    {
+        if (msg.sender != address(rootBridgeAdaptor)) {
+            revert NotBridgeAdaptor();
+        }
+        if (!Strings.equal(messageSourceChain, childChain)) {
+            revert InvalidSourceChain();
+        }
+        if (!Strings.equal(sourceAddress, childBridgeAdaptor)) {
+            revert InvalidSourceAddress();
+        }
+        if (data.length == 0) {
+            revert InvalidData();
+        }
+
+        if (bytes32(data[:32]) == WITHDRAW_SIG) {
+            _withdraw(data[32:]);
+        } else {
+            revert InvalidData();
+        }
+    }
+
     /**
      * @inheritdoc IRootERC20Bridge
      * @dev TODO when this becomes part of the deposit flow on a token's first bridge, this logic will need to be mostly moved into an internal function.
@@ -308,4 +348,32 @@ contract RootERC20Bridge is
             emit ChildChainERC20Deposit(address(rootToken), childToken, msg.sender, receiver, amount);
         }
     }
+
+    function _withdraw(bytes memory data) private {
+        (address rootToken, address withdrawer, address receiver, uint256 amount) =
+            abi.decode(data, (address, address, address, uint256));
+        address childToken = rootTokenToChildToken[rootToken];
+        if (childToken == address(0)) {
+            revert NotMapped();
+        }
+        _executeTransfer(rootToken, childToken, withdrawer, receiver, amount);
+    }
+
+    function _executeTransfer(
+        address rootToken,
+        address childToken,
+        address withdrawer,
+        address receiver,
+        uint256 amount
+    ) internal {
+        // TODO when withdrawing ETH/WETH, this next section will also need to check for the withdrawal of WETH (i.e. rootToken == NATIVE_ETH || rootToken == CHILD_WETH)
+        // Tests for this NATIVE_ETH branch not yet written. This should come as part of that PR.
+        if (rootToken == NATIVE_ETH) {
+            Address.sendValue(payable(receiver), amount);
+        } else {
+            IERC20Metadata(rootToken).safeTransfer(receiver, amount);
+        }
+        // slither-disable-next-line reentrancy-events
+        emit RootChainERC20Withdraw(address(rootToken), childToken, withdrawer, receiver, amount);
+    }
 }

src/test/child/ChildERC20FailOnBurn.sol

@@ -12,7 +12,7 @@ import "../../child/ChildERC20.sol";
  */
 // solhint-disable reason-string
 contract ChildERC20FailOnBurn is ChildERC20 {
-    function burn(address account, uint256 amount) public virtual override returns (bool) {
+    function burn(address, /*account*/ uint256 /*amount*/ ) public virtual override returns (bool) {
         return false;
     }
 }

src/test/root/MockAxelarGateway.sol

@@ -4,4 +4,8 @@ pragma solidity ^0.8.21;
 // @dev A contract for ensuring the Axelar Gateway is called correctly during unit tests.
 contract MockAxelarGateway {
     function callContract(string memory childChain, string memory childBridgeAdaptor, bytes memory payload) external {}
+
+    function validateContractCall(bytes32, string calldata, string calldata, bytes32) external pure returns (bool) {
+        return true;
+    }
 }

src/test/root/StubRootBridge.sol

@@ -7,4 +7,6 @@ contract StubRootBridge {
     function childBridgeAdaptor() external pure returns (string memory) {
         return Strings.toHexString(address(9999));
     }
+
+    function onMessageReceive(string calldata, string calldata, bytes calldata) external {}
 }