import { Buffer } from 'buffer';
import { Observable } from 'rxjs';
import { OTPVerifyResult, QrCodeGenerateOptions, U2FGenerateOptions, U2FUriOptions, U2FVerifyOptions } from '../schemas/interfaces';
export declare class U2F {
    static generateOTPKey: (asBuffer?: boolean) => Observable<Buffer | string>;
    static encodeAuthKey: (buffer: Buffer) => Observable<string>;
    static decodeAuthKey: (base32_key: string) => Observable<Buffer>;
    static generateAuthKey: () => Observable<string>;
    static generateTOTPUri: (secret: string, account_name: string, issuer: string, options?: U2FUriOptions) => Observable<string>;
    static generateAuthToken: (base32_key: string, options?: U2FGenerateOptions) => Observable<string>;
    static verifyAuthToken: (token: string, base32_key: string, options?: U2FVerifyOptions) => Observable<OTPVerifyResult | {}>;
    static qrCode: (text: string, options?: QrCodeGenerateOptions) => Observable<string | Buffer>;
}