// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v5.0.0) (utils/cryptography/SignatureChecker.sol) pragma solidity ^0.8.20; import {ECDSA} from "./ECDSA.sol"; import {IERC1271} from "../../interfaces/IERC1271.sol"; /** * @dev Signature verification helper that can be used instead of `ECDSA.recover` to seamlessly support both ECDSA * signatures from externally owned accounts (EOAs) as well as ERC-1271 signatures from smart contract wallets like * Argent and Safe Wallet (previously Gnosis Safe). */ library SignatureChecker { /** * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the * signature is validated against that smart contract using ERC-1271, otherwise it's validated using `ECDSA.recover`. * * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus * change through time. It could return true at block N and false at block N+1 (or the opposite). */ function isValidSignatureNow(address signer, bytes32 hash, bytes memory signature) internal view returns (bool) { (address recovered, ECDSA.RecoverError error, ) = ECDSA.tryRecover(hash, signature); return (error == ECDSA.RecoverError.NoError && recovered == signer) || isValidERC1271SignatureNow(signer, hash, signature); } /** * @dev Checks if a signature is valid for a given signer and data hash. The signature is validated * against the signer smart contract using ERC-1271. * * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus * change through time. It could return true at block N and false at block N+1 (or the opposite). */ function isValidERC1271SignatureNow( address signer, bytes32 hash, bytes memory signature ) internal view returns (bool) { (bool success, bytes memory result) = signer.staticcall( abi.encodeCall(IERC1271.isValidSignature, (hash, signature)) ); return (success && result.length >= 32 && abi.decode(result, (bytes32)) == bytes32(IERC1271.isValidSignature.selector)); } }