import { HMAC } from './hmac.js';
export type HKDF = {
    (chainingKey: Uint8Array, input: Uint8Array, numOutputs: 2): [Uint8Array, Uint8Array];
    (chainingKey: Uint8Array, input: Uint8Array, numOutputs: 3): [Uint8Array, Uint8Array, Uint8Array];
};
export declare function makeHKDF(hmac: HMAC): HKDF;