export interface VapidKeys {
    publicKey: string;
    privateKey: string;
}
export declare function generateVapidKeys(): Promise<VapidKeys>;
export declare function createVapidHeaders(endpoint: string, vapidSubject: string, publicKeyB64: string, privateKeyB64: string): Promise<{
    authorization: string;
    'crypto-key': string;
}>;
export interface SubscriptionKeys {
    p256dh: string;
    auth: string;
}
export declare function encryptPayload(plaintext: Uint8Array, subscriptionKeys: SubscriptionKeys): Promise<{
    ciphertext: Uint8Array;
    salt: Uint8Array;
    serverPublicKey: Uint8Array;
}>;
export declare function buildEncryptedBody(ciphertext: Uint8Array, salt: Uint8Array, serverPublicKey: Uint8Array, recordSize?: number): Uint8Array;