// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; import "../utils/cryptography/ECDSA.sol"; import "../utils/cryptography/EIP712.sol"; abstract contract EIP712Verifier is EIP712 { function verify(bytes memory signature, address signer, address mailTo, string memory mailContents) external view { 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); } }