import { DeepstreamPlugin, DeepstreamAuthentication, DeepstreamServices } from '@deepstream/types';
interface FileAuthConfig {
    users: any;
    hash: string | false;
    iterations: number;
    keyLength: number;
    reportInvalidParameters: boolean;
}
/**
 * This authentication handler reads a list of users and their associated password (either
 * hashed or in cleartext ) from a json file. This can be useful to authenticate smaller amounts
 * of clients with static credentials, e.g. backend provider that write to publicly readable records
 */
export declare class FileBasedAuthentication extends DeepstreamPlugin implements DeepstreamAuthentication {
    private settings;
    private services;
    description: string;
    private base64KeyLength;
    private hashSettings;
    /**
    * Creates the class, reads and validates the users.json file
    */
    constructor(settings: FileAuthConfig, services: DeepstreamServices);
    whenReady(): Promise<void>;
    /**
    * Main interface. Authenticates incoming connections
    */
    isValidUser(connectionData: any, authData: any): Promise<{
        isValid: boolean;
        clientData: {
            error: string;
        };
        id?: undefined;
        serverData?: undefined;
    } | {
        isValid: boolean;
        id: any;
        serverData: any;
        clientData: any;
    } | {
        isValid: boolean;
        clientData?: undefined;
        id?: undefined;
        serverData?: undefined;
    } | null>;
    /**
    * Called initially to validate the user provided settings
    */
    private validateSettings;
}
export {};