import { ByteArray } from '../types.js';
/**
 * Pads a byte array to a specified length with trailing zeros.
 *
 * @param bytes - The byte array to pad.
 * @param length - The target length for the padded array.
 * @returns A new byte array padded to the specified length.
 * @throws Error if the input array is already longer than the target length.
 *
 * @example
 * ```typescript
 * padBytes(new Uint8Array([1, 2]), 4) // Returns Uint8Array([1, 2, 0, 0])
 * ```
 */
export declare function padBytes(bytes: ByteArray, length: number): ByteArray;