/**
 * CSRF Token Service
 * Handles token generation and validation using the Double-Submit Cookie pattern.
 */
interface CsrfServiceOptions {
    tokenLength: number;
}
declare class CsrfService {
    private tokenLength;
    constructor(options: CsrfServiceOptions);
    /** Generate a cryptographically random hex token. */
    generateToken(): string;
    /** Timing-safe comparison of cookie token vs header token. */
    validateToken(cookieValue: string | undefined, headerValue: string | undefined): boolean;
    /** Build the Set-Cookie header value for a CSRF token. */
    buildCookieHeader(token: string, cookieName: string, options: {
        sameSite: string;
        secure: boolean;
        path: string;
    }): string;
}

export { CsrfService, type CsrfServiceOptions };