SignatureChecker

Title: SignatureChecker

Author: Modified from OpenZeppelin (https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/cryptography/SignatureChecker.sol)

Utility library for verifying signatures from both EOAs and ERC-1271 contracts.

Implements the ERC-1271 magic value check with a safe staticcall fallback so non-1271 contracts (or EOAs) never revert unexpectedly.

Constants

ERC1271_MAGIC_VALUE

ERC-1271 magic value returned by valid contract signatures.

bytes4 private constant ERC1271_MAGIC_VALUE = 0x1626ba7e;

Functions

isValidSignatureNow

Returns true if signer signed hash with signature.

If signer is an EOA: uses ECDSA recovery and checks address match. If signer is a contract: tries ERC-1271 isValidSignature; falls back to ECDSA if the contract call reverts (e.g. non-1271 contracts).

function isValidSignatureNow(address signer, bytes32 hash, bytes memory signature) internal view returns (bool);

Parameters

Name	Type	Description
signer	`address`	The expected signer (EOA or contract).
hash	`bytes32`	The signed data hash.
signature	`bytes`	The signature bytes.

Returns

Name	Type	Description
<none>	`bool`	True if the signature is valid for the given signer and hash.

isValidERC1271SignatureNow

Returns true if the contract signer accepts signature for hash via ERC-1271.

Calls signer.isValidSignature(hash, signature) via staticcall and checks the magic return value. Never reverts — returns false if the call fails.

function isValidERC1271SignatureNow(address signer, bytes32 hash, bytes memory signature)
        internal
        view
        returns (bool);

Parameters

Name	Type	Description
signer	`address`	The contract that implements (or should implement) ERC-1271.
hash	`bytes32`	The signed data hash.
signature	`bytes`	The signature bytes.

Returns

Name	Type	Description
<none>	`bool`	True if the contract returns the ERC-1271 magic value.