token wrapped bridge contract

contracts/lib/TokenWrappedBridge.sol

@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-3.0
+// Implementation of permit based on https://github.com/WETH10/WETH10/blob/main/contracts/WETH10.sol
+pragma solidity 0.8.17;
+
+import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+
+contract TokenWrapped is ERC20 {
+    // Domain typehash
+    bytes32 public constant DOMAIN_TYPEHASH =
+        keccak256(
+            "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
+        );
+    // Permit typehash
+    bytes32 public constant PERMIT_TYPEHASH =
+        keccak256(
+            "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
+        );
+
+    // Version
+    string public constant VERSION = "1";
+
+    // Chain id on deployment
+    uint256 public immutable deploymentChainId;
+
+    // Domain separator calculated on deployment
+    bytes32 private immutable _DEPLOYMENT_DOMAIN_SEPARATOR;
+
+    // PolygonZkEVM Bridge address
+    address public immutable bridgeAddress;
+
+    // Decimals
+    uint8 private immutable _decimals;
+
+    // Permit nonces
+    mapping(address => uint256) public nonces;
+
+    modifier onlyBridge() {
+        require(
+            msg.sender == bridgeAddress,
+            "TokenWrapped::onlyBridge: Not PolygonZkEVMBridge"
+        );
+        _;
+    }
+
+    constructor(
+        string memory name,
+        string memory symbol,
+        uint8 __decimals
+    ) ERC20(name, symbol) {
+        bridgeAddress = msg.sender;
+        _decimals = __decimals;
+        deploymentChainId = block.chainid;
+        _DEPLOYMENT_DOMAIN_SEPARATOR = _calculateDomainSeparator(block.chainid);
+    }
+
+    function mint(address to, uint256 value) external onlyBridge {
+        _mint(to, value);
+    }
+
+    // Notice that is not require to approve wrapped tokens to use the bridge
+    function burn(address account, uint256 value) external onlyBridge {
+        _burn(account, value);
+    }
+
+    function decimals() public view virtual override returns (uint8) {
+        return _decimals;
+    }
+
+    // Permit relative functions
+    function permit(
+        address owner,
+        address spender,
+        uint256 value,
+        uint256 deadline,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) external {
+        require(
+            block.timestamp <= deadline,
+            "TokenWrapped::permit: Expired permit"
+        );
+
+        bytes32 hashStruct = keccak256(
+            abi.encode(
+                PERMIT_TYPEHASH,
+                owner,
+                spender,
+                value,
+                nonces[owner]++,
+                deadline
+            )
+        );
+
+        bytes32 digest = keccak256(
+            abi.encodePacked("\x19\x01", DOMAIN_SEPARATOR(), hashStruct)
+        );
+
+        address signer = ecrecover(digest, v, r, s);
+        require(
+            signer != address(0) && signer == owner,
+            "TokenWrapped::permit: Invalid signature"
+        );
+
+        _approve(owner, spender, value);
+    }
+
+    /**
+     * @notice Calculate domain separator, given a chainID.
+     * @param chainId Current chainID
+     */
+    function _calculateDomainSeparator(
+        uint256 chainId
+    ) private view returns (bytes32) {
+        return
+            keccak256(
+                abi.encode(
+                    DOMAIN_TYPEHASH,
+                    keccak256(bytes(name())),
+                    keccak256(bytes(VERSION)),
+                    chainId,
+                    address(this)
+                )
+            );
+    }
+
+    /// @dev Return the DOMAIN_SEPARATOR.
+    function DOMAIN_SEPARATOR() public view returns (bytes32) {
+        return
+            block.chainid == deploymentChainId
+                ? _DEPLOYMENT_DOMAIN_SEPARATOR
+                : _calculateDomainSeparator(block.chainid);
+    }
+}