/**
 * Shared Digest Authentication session manager.
 * Caches auth parameters (realm, nonce, HA1) to avoid a 401 round-trip
 * on every request. Used by both PhilipsTVClient and NotifyChangeClient.
 */
export declare class DigestAuthSession {
    private readonly username;
    private readonly password;
    private cachedAuth;
    constructor(username: string, password: string);
    /** Whether we have cached credentials (can skip the initial 401). */
    get hasCachedAuth(): boolean;
    /** Clear cached auth state (e.g., on nonce expiry). */
    clear(): void;
    /**
     * Build a digest Authorization header using cached auth parameters.
     * Increments the nonce count for each use.
     * Returns null if no cached auth is available.
     */
    buildHeader(method: string, uri: string): string | null;
    /**
     * Parse a WWW-Authenticate header from a 401 response and cache
     * the digest parameters for future requests.
     * Returns false if the header is not a valid Digest challenge.
     */
    cacheFromChallenge(wwwAuthHeader: string): boolean;
}