feat: initialize a prototypes (#162)

Co-authored-by: skosito <skostic9242@gmail.com>
Co-authored-by: Francisco de Borja Aranda Castillejo <me@fbac.dev>

contracts/prototypes/evm/ERC20CustodyNew.sol

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.7;
+
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "./interfaces.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
+
+// As the current version, ERC20CustodyNew hold the ERC20s deposited on ZetaChain
+// This version include a functionality allowing to call a contract
+// ERC20Custody doesn't call smart contract directly, it passes through the Gateway contract
+contract ERC20CustodyNew is ReentrancyGuard{
+    using SafeERC20 for IERC20;
+    error ZeroAddress();
+
+    IGatewayEVM public gateway;
+
+    event Withdraw(address indexed token, address indexed to, uint256 amount);
+    event WithdrawAndCall(address indexed token, address indexed to, uint256 amount, bytes data);
+
+    constructor(address _gateway) {
+         if (_gateway == address(0)) {
+            revert ZeroAddress();
+        }
+        gateway = IGatewayEVM(_gateway);
+    }
+
+    // Withdraw is called by TSS address, it directly transfers the tokens to the destination address without contract call
+    // TODO: Finalize access control
+    // https://github.com/zeta-chain/protocol-contracts/issues/204
+    function withdraw(address token, address to, uint256 amount) external nonReentrant {
+        IERC20(token).safeTransfer(to, amount);
+
+        emit Withdraw(token, to, amount);
+    }
+
+    // WithdrawAndCall is called by TSS address, it transfers the tokens and call a contract
+    // For this, it passes through the Gateway contract, it transfers the tokens to the Gateway contract and then calls the contract
+    // TODO: Finalize access control
+    // https://github.com/zeta-chain/protocol-contracts/issues/204
+    function withdrawAndCall(address token, address to, uint256 amount, bytes calldata data) external nonReentrant {
+        // Transfer the tokens to the Gateway contract
+        IERC20(token).safeTransfer(address(gateway), amount);
+
+        // Forward the call to the Gateway contract
+        gateway.executeWithERC20(token, to, amount, data);
+
+        emit WithdrawAndCall(token, to, amount, data);
+    }
+}

contracts/prototypes/evm/GatewayEVM.sol

@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.7;
+
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
+import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
+
+// The GatewayEVM contract is the endpoint to call smart contracts on external chains
+// The contract doesn't hold any funds and should never have active allowances
+contract GatewayEVM is Initializable, OwnableUpgradeable, UUPSUpgradeable {
+    using SafeERC20 for IERC20;
+
+    error ExecutionFailed();
+    error DepositFailed();
+    error InsufficientETHAmount();
+    error InsufficientERC20Amount();
+    error ZeroAddress();
+    error ApprovalFailed();
+
+    address public custody;
+    address public tssAddress;
+
+    event Executed(address indexed destination, uint256 value, bytes data);
+    event ExecutedWithERC20(address indexed token, address indexed to, uint256 amount, bytes data);
+    event Deposit(address indexed sender, address indexed receiver, uint256 amount, address asset, bytes payload);
+    event Call(address indexed sender, address indexed receiver, bytes payload);
+
+    /// @custom:oz-upgrades-unsafe-allow constructor
+    constructor() {
+        _disableInitializers();
+    }
+
+    function initialize(address _tssAddress) public initializer {
+        __Ownable_init();
+        __UUPSUpgradeable_init();
+
+        if (_tssAddress == address(0)) revert ZeroAddress();
+
+        tssAddress = _tssAddress;
+    }
+
+    function _authorizeUpgrade(address newImplementation) internal override onlyOwner() {}
+
+    function _execute(address destination, bytes calldata data) internal returns (bytes memory) {
+        (bool success, bytes memory result) = destination.call{value: msg.value}(data);
+
+        if (!success) revert ExecutionFailed();
+
+        return result;
+    }
+
+    // Called by the TSS
+    // Execution without ERC20 tokens, it is payable and can be used in the case of WithdrawAndCall for Gas ZRC20
+    // It can be also used for contract call without asset movement
+    function execute(address destination, bytes calldata data) external payable returns (bytes memory) {
+        bytes memory result = _execute(destination, data);
+
+        emit Executed(destination, msg.value, data);
+
+        return result;
+    }
+
+    // Called by the ERC20Custody contract
+    // It call a function using ERC20 transfer
+    // Since the goal is to allow calling contract not designed for ZetaChain specifically, it uses ERC20 allowance system
+    // It provides allowance to destination contract and call destination contract. In the end, it remove remaining allowance and transfer remaining tokens back to the custody contract for security purposes
+    function executeWithERC20(
+        address token,
+        address to,
+        uint256 amount,
+        bytes calldata data
+    ) external returns (bytes memory) {
+        if (amount == 0) revert InsufficientETHAmount();
+        // Approve the target contract to spend the tokens
+        if(!resetApproval(token, to)) revert ApprovalFailed();
+        if(!IERC20(token).approve(to, amount)) revert ApprovalFailed();
+
+        // Execute the call on the target contract
+        bytes memory result = _execute(to, data);
+
+        // Reset approval
+        if(!resetApproval(token, to)) revert ApprovalFailed();
+
+        // Transfer any remaining tokens back to the custody contract
+        uint256 remainingBalance = IERC20(token).balanceOf(address(this));
+        if (remainingBalance > 0) {
+            IERC20(token).safeTransfer(address(custody), remainingBalance);
+        }
+
+        emit ExecutedWithERC20(token, to, amount, data);
+
+        return result;
+    }
+
+    // Deposit ETH to tss
+    function deposit(address receiver) external payable {
+        if (msg.value == 0) revert InsufficientETHAmount();
+        (bool deposited, ) = tssAddress.call{value: msg.value}("");
+
+        if (deposited == false) revert DepositFailed();
+
+        emit Deposit(msg.sender, receiver, msg.value, address(0), "");
+    }
+
+    // Deposit ERC20 tokens to custody
+    function deposit(address receiver, uint256 amount, address asset) external {
+        if (amount == 0) revert InsufficientERC20Amount();
+        IERC20(asset).safeTransferFrom(msg.sender, address(custody), amount);
+
+        emit Deposit(msg.sender, receiver, amount, asset, "");
+    }
+
+    // Deposit ETH to tss and call an omnichain smart contract
+    function depositAndCall(address receiver, bytes calldata payload) external payable {
+        if (msg.value == 0) revert InsufficientETHAmount();
+        (bool deposited, ) = tssAddress.call{value: msg.value}("");
+
+        if (deposited == false) revert DepositFailed();
+
+        emit Deposit(msg.sender, receiver, msg.value, address(0), payload);
+    }
+
+    // Deposit ERC20 tokens to custody and call an omnichain smart contract
+    function depositAndCall(address receiver, uint256 amount, address asset, bytes calldata payload) external {
+        if (amount == 0) revert InsufficientERC20Amount();
+        IERC20(asset).safeTransferFrom(msg.sender, address(custody), amount);
+
+        emit Deposit(msg.sender, receiver, amount, asset, payload);
+    }
+
+    // Call an omnichain smart contract without asset transfer
+    function call(address receiver, bytes calldata payload) external {
+        emit Call(msg.sender, receiver, payload);
+    }
+
+    function setCustody(address _custody) external {
+        custody = _custody;
+    }
+
+    function resetApproval(address token, address to) private returns (bool) {
+        return IERC20(token).approve(to, 0);
+    }
+}

contracts/prototypes/evm/GatewayEVMUpgradeTest.sol

@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.7;
+
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
+import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
+
+
+// NOTE: Purpose of this contract is to test upgrade process, the only difference should be name of Executed event
+// The Gateway contract is the endpoint to call smart contracts on external chains
+// The contract doesn't hold any funds and should never have active allowances
+contract GatewayEVMUpgradeTest is Initializable, OwnableUpgradeable, UUPSUpgradeable {
+    using SafeERC20 for IERC20;
+
+    error ExecutionFailed();
+    error SendFailed();
+    error InsufficientETHAmount();
+    error ZeroAddress();
+    error ApprovalFailed();
+
+    address public custody;
+    address public tssAddress;
+
+    event ExecutedV2(address indexed destination, uint256 value, bytes data);
+    event ExecutedWithERC20(address indexed token, address indexed to, uint256 amount, bytes data);
+    event SendERC20(bytes recipient, address indexed asset, uint256 amount);
+    event Send(bytes recipient, uint256 amount);
+
+    /// @custom:oz-upgrades-unsafe-allow constructor
+    constructor() {
+        _disableInitializers();
+    }
+
+    function initialize(address _tssAddress) public initializer {
+        __Ownable_init();
+        __UUPSUpgradeable_init();
+
+        if (_tssAddress == address(0)) revert ZeroAddress();
+
+        tssAddress = _tssAddress;
+    }
+
+    function _authorizeUpgrade(address newImplementation) internal override onlyOwner() {}
+
+    function _execute(address destination, bytes calldata data) internal returns (bytes memory) {
+        (bool success, bytes memory result) = destination.call{value: msg.value}(data);
+
+        if (!success) revert ExecutionFailed();
+
+        return result;
+    }
+
+    // Called by the TSS
+    // Execution without ERC20 tokens, it is payable and can be used in the case of WithdrawAndCall for Gas ZRC20
+    // It can be also used for contract call without asset movement
+    function execute(address destination, bytes calldata data) external payable returns (bytes memory) {
+        bytes memory result = _execute(destination, data);
+
+        emit ExecutedV2(destination, msg.value, data);
+
+        return result;
+    }
+
+    // Called by the ERC20Custody contract
+    // It call a function using ERC20 transfer
+    // Since the goal is to allow calling contract not designed for ZetaChain specifically, it uses ERC20 allowance system
+    // It provides allowance to destination contract and call destination contract. In the end, it remove remaining allowance and transfer remaining tokens back to the custody contract for security purposes
+    function executeWithERC20(
+        address token,
+        address to,
+        uint256 amount,
+        bytes calldata data
+    ) external returns (bytes memory) {
+        // Approve the target contract to spend the tokens
+        if(!IERC20(token).approve(to, 0)) revert ApprovalFailed();
+        if(!IERC20(token).approve(to, amount)) revert ApprovalFailed();
+
+        // Execute the call on the target contract
+        bytes memory result = _execute(to, data);
+
+        // Reset approval
+        if(!IERC20(token).approve(to, 0)) revert ApprovalFailed();
+
+        // Transfer any remaining tokens back to the custody contract
+        uint256 remainingBalance = IERC20(token).balanceOf(address(this));
+        if (remainingBalance > 0) {
+            IERC20(token).safeTransfer(address(custody), remainingBalance);
+        }
+
+        emit ExecutedWithERC20(token, to, amount, data);
+
+        return result;
+    }
+
+    // Transfer specified token amount to ERC20Custody and emits event
+    function sendERC20(bytes calldata recipient, address token, uint256 amount) external {
+        IERC20(token).safeTransferFrom(msg.sender, address(custody), amount);
+
+        emit SendERC20(recipient, token, amount);
+    }
+
+    // Transfer specified ETH amount to TSS address and emits event
+    function send(bytes calldata recipient, uint256 amount) external payable {
+        if (msg.value == 0) revert InsufficientETHAmount();
+
+        (bool sent, ) = tssAddress.call{value: msg.value}("");
+
+        if (sent == false) revert SendFailed();
+
+        emit Send(recipient, msg.value);
+    }
+
+    function setCustody(address _custody) external {
+        custody = _custody;
+    }
+}

contracts/prototypes/evm/Receiver.sol

@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.7;
+
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+
+contract Receiver {
+    using SafeERC20 for IERC20;
+
+    event ReceivedPayable(address sender, uint256 value, string str, uint256 num, bool flag);
+    event ReceivedNonPayable(address sender, string[] strs, uint256[] nums, bool flag);
+    event ReceivedERC20(address sender, uint256 amount, address token, address destination);
+    event ReceivedNoParams(address sender);
+
+    // Payable function
+    function receivePayable(string memory str, uint256 num, bool flag) external payable {
+        emit ReceivedPayable(msg.sender, msg.value, str, num, flag);
+    }
+
+    // Non-payable function
+    function receiveNonPayable(string[] memory strs, uint256[] memory nums, bool flag) external {
+        emit ReceivedNonPayable(msg.sender, strs, nums, flag);
+    }
+
+    // Function using IERC20
+    function receiveERC20(uint256 amount, address token, address destination) external {
+        // Transfer tokens from the Gateway contract to the destination address
+        IERC20(token).safeTransferFrom(msg.sender, destination, amount);
+
+        emit ReceivedERC20(msg.sender, amount, token, destination);
+    }
+
+    // Function without parameters
+    function receiveNoParams() external {
+        emit ReceivedNoParams(msg.sender);
+    }
+}

contracts/prototypes/evm/TestERC20.sol

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.7;
+
+import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+
+contract TestERC20 is ERC20 {
+    constructor(string memory name, string memory symbol) ERC20(name, symbol) {}
+
+    function mint(address to, uint256 amount) external {
+        _mint(to, amount);
+    }
+}

contracts/prototypes/evm/interfaces.sol

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.7;
+
+interface IGatewayEVM {
+    function executeWithERC20(
+        address token,
+        address to,
+        uint256 amount,
+        bytes calldata data
+    ) external returns (bytes memory);
+
+    function execute(address destination, bytes calldata data) external payable returns (bytes memory);
+
+    function sendERC20(bytes calldata recipient, address asset, uint256 amount) external;
+
+    function send(bytes calldata recipient, uint256 amount) external payable;
+}