import { Base32SecretKey, SecretKey } from '@otplib/core';
import type { Token, TokenOptions } from './types';
export declare class OtpService {
    /**
     * Authenticator extends TOTP, usable for both purposes
     *
     * The only difference is that Authenticator uses Base32 encoding type
     * while TOTP uses hexadecimal.
     *
     * @private
     */
    private readonly authenticator;
    /**
     * Generates an RFC 3548 / RFC 4226 compliant Base32 string compatible with
     * Google Authenticator
     *
     * @internal
     */
    generateSecret(byteLength?: number): Base32SecretKey;
    /**
     * Generates a Time-Based One-Time Password (TOTP)
     *
     * If using an authenticator application, then the token is generated in
     * client side.
     *
     * This is useful if you want to use an email as a second factor.
     *
     * @public
     * @param secret
     * @param options
     */
    generateToken(secret: SecretKey, options?: TokenOptions): Token;
    /**
     * Generates a Key URI for authenticator app registration (optionally encoded as QR code)
     *
     * @public
     * @param secret
     * @param issuer
     * @param accountName
     */
    generateKeyUri(secret: SecretKey, issuer: string, accountName: string): string;
    /**
     * Verifies token
     *
     * @public
     * @param secret
     * @param token
     */
    verify(secret: SecretKey, token: Token): boolean;
}