ERC1271

Git Source

Author: Adapted from Solady (https://github.com/vectorized/solady/blob/main/src/accounts/ERC1271.sol)

Abstract ERC-1271 implementation with guards to handle the same signer being used on multiple accounts.

To prevent the same signature from being validated on different accounts owned by the samer signer, we introduce an anti cross-account-replay layer: the original hash is input into a new EIP-712 compliant hash. The domain separator of this outer hash contains the chain id and address of this contract, so that it cannot be used on two accounts (see replaySafeHash() for the implementation details).

State Variables

_WALLET_MESSAGE_TYPEHASH

Precomputed typeHash used to produce EIP-712 compliant hash when applying the anti cross-account-replay layer.

bytes32 private constant _WALLET_MESSAGE_TYPEHASH = keccak256("SmartWalletMessage(bytes32 hash)");

Functions

eip712Domain

function eip712Domain()
    external
    view
    virtual
    returns (
        bytes1 fields,
        string memory name,
        string memory version,
        uint256 chainId,
        address verifyingContract,
        bytes32 salt,
        uint256[] memory extensions
    );

isValidSignature

function isValidSignature(bytes32 hash, bytes calldata signature) public view virtual returns (bytes4 result);

replaySafeHash

function replaySafeHash(bytes32 hash) public view virtual returns (bytes32);

domainSeparator

function domainSeparator() public view virtual returns (bytes32);

_eip712Hash

function _eip712Hash(bytes32 hash) internal view virtual returns (bytes32);

_hashStruct

function _hashStruct(bytes32 hash) internal view virtual returns (bytes32);

_domainNameAndVersion

function _domainNameAndVersion() internal view virtual returns (string memory name, string memory version);

_isValidSignature

function _isValidSignature(bytes32 hash, bytes calldata signature) internal view virtual returns (bool);