/// <reference types="node" />
import type { EncryptedFlowRequest, DecryptionResult, FlowKeyPair } from './types';
export declare function decryptRequest(encryptedRequest: EncryptedFlowRequest, privateKeyPem: string): DecryptionResult;
export declare function encryptResponse(response: object, aesKey: Buffer, iv: Buffer): string;
export declare function generateKeyPair(): FlowKeyPair;
export declare function validateSignature(payload: string, signature: string, appSecret: string): boolean;