/**
 * Returns a signing key to be used for signing requests.
 *
 * @param secretAccessKey AWS secret access key from credentials.
 * @param date Current date in the format 'YYYYMMDD'.
 * @param region AWS region in which the service resides.
 * @param service Service to which the signed request is being sent.
 *
 * @returns `Uint8Array` calculated from its composite parts.
 *
 * @internal
 */
export declare const getSigningKey: (secretAccessKey: string, date: string, region: string, service: string) => Uint8Array;