import * as pkcs11 from "pkcs11js";
import * as core from "../core";
import * as mech from "../mech";
import { Session } from "../session";
import { Key } from '../objects';
import * as types from '../types';
/**
 * Represents signing operation
 */
export declare class Sign extends core.BaseObject {
    /**
     * Session
     */
    session: Session;
    /**
     * Creates a new instance of signing operation
     * @param session Session
     * @param alg The signing mechanism
     * @param key The signing key
     * @param lib PKCS#11 library
     */
    constructor(session: Session, alg: mech.MechanismType, key: Key, lib: pkcs11.PKCS11);
    /**
     * Continues a multiple-part signature operation, where the signature is (will be) an appendix to the data
     * @param data The data to be signed
     */
    update(data: types.CryptoData): void;
    /**
     * Finishes a multiple-part signature operation, returning the signature
     * @returns The signature value
     */
    final(): Buffer;
    /**
     * Signs (encrypts with private key) data in a single part
     * @param data The data to be signed
     * @returns Signature value
     */
    once(data: types.CryptoData): Buffer;
    /**
     * Signs (encrypts with private key) data in a single part
     * @param data The data to be signed
     * @param cb Async callback function with signature value
     */
    once(data: types.CryptoData, cb: (error: Error, data: Buffer) => void): void;
    /**
     * initializes a signature (private key encryption) operation
     * @param alg The signing mechanism
     * @param key The signing key
     */
    protected init(alg: mech.MechanismType, key: Key): void;
}