export declare class Decrypter {
    private key;
    private keyArray;
    private readonly headerLength;
    /**
     * @param {string} key Encryption key, that can be fetched from `System.json`'s `encryptionKey` field. Leave it `null` to auto-determine the key from input files. You can set it after constructing `Decrypter` using `Decrypter.setKeyFromImage()` or `Decrypter.setKey()`.
     */
    constructor(key?: string | null);
    private splitEncryptionCode;
    private processBuffer;
    /**
     * Returns the decrypter's key.
     *
     * Falls back to empty string if key is not set.
     */
    getKey(): string;
    /**
     * @param key {string} Sets the key of decrypter to provided string.
     */
    setKeyString(key: string): void;
    /**
     * Sets the key of decrypter from encrypted `fileContent` image data.
     * @param {ArrayBuffer} fileContent The data of RPG Maker file.
     */
    setKeyFromImage(fileContent: ArrayBuffer): void;
    /**
     * The function will return wrong data, when used with audio (`rpgmvo`, `rpgmvm`, `ogg_`, `m4a_`) file without an explicitly set key.
     * @param {ArrayBuffer} fileContent The data of RPG Maker file.
     * @returns {ArrayBuffer} Decrypted data.
     */
    decrypt(fileContent: ArrayBuffer): ArrayBuffer;
    /**
     * This function needs decrypter to have a key, which you can fetch from `System.json` file or by calling `Decrypter.setKeyFromImage()`/`Decrypter.setKeyString()`.
     * @param {ArrayBuffer} fileContent The data of `.png`, `.ogg` or `.m4a` file.
     * @returns {ArrayBuffer} Encrypted data.
     */
    encrypt(fileContent: ArrayBuffer): ArrayBuffer;
}