export declare class MediaKeyError extends Error {
    constructor(message: string);
}
/**
 * Resolve a caller-supplied media key against the configured mediaRoot.
 *
 * @throws {MediaKeyError} when the key is empty, absolute, contains a NUL
 * byte, uses path traversal, or escapes mediaRoot.
 */
export declare function resolveKey(mediaRoot: string, rawKey: unknown, options?: {
    decode?: boolean;
}): string;
/**
 * Resolve a caller-supplied listing directory into a relative prefix.
 *
 * The directory is optional: an empty / root directory returns `''` (list the
 * mediaRoot itself). Otherwise leading/trailing slashes are stripped (matching
 * the historical handler behaviour) and the result is normalised so it cannot
 * traverse upward — `path.join(mediaRoot, directory)` would otherwise collapse
 * `..` and list objects outside mediaRoot. Returns a prefix with a trailing
 * slash so it can be joined onto mediaRoot directly.
 *
 * @throws {MediaKeyError} when the directory contains a NUL byte or backslash,
 * or uses upward path traversal.
 */
export declare function resolveDirectory(rawDirectory: unknown): string;