import { providers, Signer } from 'ethers';
import type { SiweMessage } from './client';
/**
 * This method calls the EIP-1271 method for Smart Contract wallets
 * @param message The EIP-4361 parsed message
 * @param provider Web3 provider able to perform a contract check (Web3/EthersJS).
 * @returns {Promise<boolean>} Checks for the smart contract (if it exists) if
 * the signature is valid for given address.
 */
export declare const checkContractWalletSignature: (message: SiweMessage, signature: string, provider?: providers.Provider | Signer) => Promise<boolean>;
/**
 * This method leverages a native CSPRNG with support for both browser and Node.js
 * environments in order generate a cryptographically secure nonce for use in the
 * SiweMessage in order to prevent replay attacks.
 *
 * 96 bits has been chosen as a number to sufficiently balance size and security considerations
 * relative to the lifespan of it's usage.
 *
 * @returns cryptographically generated random nonce with 96 bits of entropy encoded with
 * an alphanumeric character set.
 */
export declare const generateNonce: () => string;
/**
 * This method matches the given date string against the ISO-8601 regex and also
 * performs checks if it's a valid date.
 * @param inputDate any string to be validated against ISO-8601
 * @returns boolean indicating if the providade date is valid and conformant to ISO-8601
 */
export declare const isValidISO8601Date: (inputDate: string) => boolean;
export declare const checkInvalidKeys: <T>(obj: T, keys: (keyof T)[]) => (keyof T)[];