/**
 * @license
 * Copyright 2017 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/**
 * 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;
