export declare class Base64Service {
    private static _keyStr;
    /**
     * 加密
     *
     * @param {any} input
     * @returns {string}
     *
     * @memberOf Base64Service
     */
    static encode(input: string): string;
    /**
     * 解密
     *
     * @param {any} input
     * @returns
     *
     * @memberOf Base64Service
     */
    static decode(input: string): string;
    private static _utf8_encode(str);
    private static _utf8_decode(utftext);
}