/**
 * Decodes a Firebase auth. token into constituent parts.
 *
 * Notes:
 * - May return with invalid / incomplete claims if there's no native base64 decoding support.
 * - Doesn't check if the token is actually valid.
 *
 * @param {?string} token
 * @return {{header: *, claims: *, data: *, signature: string}}
 */
export declare const decode: (token: any) => {
    header: {};
    claims: {};
    data: {};
    signature: string;
};
/**
 * Decodes a Firebase auth. token and checks the validity of its time-based claims. Will return true if the
 * token is within the time window authorized by the 'nbf' (not-before) and 'iat' (issued-at) claims.
 *
 * Notes:
 * - May return a false negative if there's no native base64 decoding support.
 * - Doesn't check if the token is actually valid.
 *
 * @param {?string} token
 * @return {boolean}
 */
export declare const isValidTimestamp: (token: any) => boolean;
/**
 * Decodes a Firebase auth. token and returns its issued at time if valid, null otherwise.
 *
 * Notes:
 * - May return null if there's no native base64 decoding support.
 * - Doesn't check if the token is actually valid.
 *
 * @param {?string} token
 * @return {?number}
 */
export declare const issuedAtTime: (token: any) => any;
/**
 * Decodes a Firebase auth. token and checks the validity of its format. Expects a valid issued-at time.
 *
 * Notes:
 * - May return a false negative if there's no native base64 decoding support.
 * - Doesn't check if the token is actually valid.
 *
 * @param {?string} token
 * @return {boolean}
 */
export declare const isValidFormat: (token: any) => boolean;
/**
 * Attempts to peer into an auth token and determine if it's an admin auth token by looking at the claims portion.
 *
 * Notes:
 * - May return a false negative if there's no native base64 decoding support.
 * - Doesn't check if the token is actually valid.
 *
 * @param {?string} token
 * @return {boolean}
 */
export declare const isAdmin: (token: any) => boolean;