import type { ClientRequest, ServerResponse } from 'http';
export interface ExpressRequest extends ClientRequest {
    body: CallbackPayload;
    headers: Record<string, string>;
}
/**
 * @public
 */
export type CallbackPayload = {
    Action: string;
    CompanyId: string | number;
    Entity: string;
    FromUrl: string;
    ID: string | number;
    MemberId: string | number;
    Metadata: {
        key_url: string;
    };
    Type: string;
};
export type Entity = Record<string, unknown> | Array<Record<string, unknown>>;
/**
 * Load signing key and verify the message
 * @param callbackBody -
 * @param contentSignature - base64 content signature req.headers[x-content-signature]
 * @returns verifies callback signature
 * @public
 */
export declare function verifyCallback(callbackBody: CallbackPayload, contentSignature: string): Promise<boolean>;
/**
 * Validate a callback body against signed key
 * @param callbackBody -
 * @param contentSignature -
 * @param signingKey -
 * @returns boolean if verified
 * @public
 */
export declare function verifyMessage(callbackBody: CallbackPayload, contentSignature: string, signingKey: string): boolean;
/**
 *
 * @example
 * Express style middleware
 * ```
 * app.post('/your/api', cw.utils.middleware((err, req, res, verified, payload) => {
 *  if (err) {
 *    //handle error
 *    res.status(500).end();
 *  } else if (!verified) {
 *    // send 403 on verification failure
 *    res.status(403).end();
 *  } else {
 *    res.status(200).end()
 *  }
 *  const {action, id} = req.query;
 *  // do something with the payload
 * }));
 * ```
 *
 * @param cb - callback(err, req, res, verified, payload)
 * @public
 */
export declare function middleware(cb: (err: Error | null, req: ExpressRequest, res: ServerResponse, verified: boolean, payload: Entity | undefined) => void): (req: ExpressRequest, res: ServerResponse) => void;
declare const _default: {
    middleware: typeof middleware;
    verifyCallback: typeof verifyCallback;
    verifyMessage: typeof verifyMessage;
};
export default _default;
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