Simple EIP712 example

script/Deploy.s.sol

@@ -12,9 +12,9 @@ contract NFTMarketDeploy is BaseScript {
         uint256 deployPrivateKey = vm.envUint("PRIVATE_KEY");
         vm.startBroadcast(deployPrivateKey);
         BaseERC20 token = new BaseERC20(vm.envAddress("ETH_FROM"));
-        MyERC721 myNFT = new MyERC721();
+        // MyERC721 myNFT = new MyERC721();
 
-        NFTMarket nft = new NFTMarket(address(myNFT), address(token));
+        // NFTMarket nft = new NFTMarket(address(myNFT), address(token));
 
         vm.stopBroadcast();
     }

src/examples/SimpleEIP712.sol

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.13;
+
+import { EIP712 } from "@openzeppelin/contracts/utils/cryptography/EIP712.sol";
+import { ECDSA } from "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
+
+contract SimpleEIP712 is EIP712 {
+    constructor() EIP712("test", "1.0") { }
+
+    struct Mail {
+        address to;
+        string contents;
+    }
+
+    function verify(
+        bytes memory signature,
+        address signer,
+        address mailTo,
+        string memory mailContents
+    )
+        external
+        view
+        returns (address)
+    {
+        bytes32 digest = _hashTypedDataV4(
+            keccak256(abi.encode(keccak256("Mail(address to,string contents)"), mailTo, keccak256(bytes(mailContents))))
+        );
+        address recoveredSigner = ECDSA.recover(digest, signature);
+        require(recoveredSigner == signer, "signers not equal");
+        return recoveredSigner;
+    }
+}

test/examples/EIP712.t.sol

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.13;
+
+import { Test, console2 } from "forge-std/src/Test.sol";
+import { SimpleEIP712 } from "../../src/examples/SimpleEIP712.sol";
+import { MessageHashUtils } from "@openzeppelin/contracts/utils/cryptography/MessageHashUtils.sol";
+
+contract EIP172Test is Test {
+    using MessageHashUtils for bytes32;
+
+    SimpleEIP712 simpleEIP712;
+    address alice;
+    uint256 alicePk;
+
+    function setUp() public {
+        simpleEIP712 = new SimpleEIP712();
+        (alice, alicePk) = makeAddrAndKey("alice");
+    }
+
+    function testVerify() public {
+        // bytes memory signature,
+        // address signer,
+        // address mailTo,
+        // string memory mailContents
+
+        vm.startPrank(alice);
+        uint256 price = 1e6;
+        uint256 tokenId = 0;
+        bytes32 hash = keccak256(abi.encodePacked(tokenId + price)).toEthSignedMessageHash();
+        (uint8 v, bytes32 r, bytes32 s) = vm.sign(alicePk, hash);
+
+        simpleEIP712.verify(tokenId, price, v, r, s);
+
+        vm.stopPrank();
+    }
+}