openzeppelin-contracts/contracts/interfaces/IERC1271.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC1271 standard signature validation method for
 * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
 */
interface IERC1271 {
  /**
   * @dev Should return whether the signature provided is valid for the provided data
   * @param hash      Hash of the data to be signed
   * @param signature Signature byte array associated with _data
   */
  function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue);
}