import { type KeyLike } from 'crypto';
import type { OverlaySignatureAlgorithm, OverlaySpec, SignedOverlaySpec } from './spec';
export interface SignOverlayOptions {
    algorithm?: OverlaySignatureAlgorithm;
    keyId?: string;
    issuedAt?: Date | string;
    expiresAt?: Date | string;
    metadata?: Record<string, unknown>;
    publicKey?: string;
}
export declare function signOverlay(spec: OverlaySpec, privateKey: KeyLike | string | Buffer, options?: SignOverlayOptions): SignedOverlaySpec;
export declare function verifyOverlaySignature(overlay: SignedOverlaySpec): boolean;
export declare function canonicalizeOverlay(spec: OverlaySpec | SignedOverlaySpec): string;
export declare function stripSignature<T extends OverlaySpec | SignedOverlaySpec>(spec: T): OverlaySpec;