com.google.firebase.database.core.JvmAuthTokenProvider Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of firebase-admin Show documentation
This is the official Firebase Admin Java SDK. Build extraordinary native JVM apps in minutes with Firebase. The Firebase platform can power your app’s backend, user authentication, static hosting, and more.
There is a newer version: 9.4.1
Show newest version
/*
 * 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.
 */

package com.google.firebase.database.core;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.auth.oauth2.AccessToken;
import com.google.auth.oauth2.GoogleCredentials;
import com.google.auth.oauth2.OAuth2Credentials;
import com.google.auth.oauth2.OAuth2Credentials.CredentialsChangedListener;
import com.google.firebase.FirebaseApp;
import com.google.firebase.ImplFirebaseTrampolines;
import com.google.firebase.database.util.GAuthToken;

import java.io.IOException;
import java.util.Map;
import java.util.concurrent.Executor;

public class JvmAuthTokenProvider implements AuthTokenProvider {

  private final GoogleCredentials credentials;
  private final Map authVariable;
  private final Executor executor;

  JvmAuthTokenProvider(FirebaseApp firebaseApp, Executor executor) {
    this(firebaseApp, executor, true);
  }

  JvmAuthTokenProvider(FirebaseApp firebaseApp, Executor executor, boolean autoRefresh) {
    this.credentials = ImplFirebaseTrampolines.getCredentials(firebaseApp);
    this.authVariable = firebaseApp.getOptions().getDatabaseAuthVariableOverride();
    this.executor = executor;
    if (autoRefresh) {
      ImplFirebaseTrampolines.startTokenRefresher(firebaseApp);
    }
  }

  @Override
  public void getToken(boolean forceRefresh, final GetTokenCompletionListener listener) {
    try {
      if (forceRefresh) {
        credentials.refresh();
      }

      // The typical way to use a GoogleCredentials instance is to call its getRequestMetadata(),
      // and include the metadata in your request. Since we are accessing the token directly via
      // getAccessToken(), we must first call getRequestMetadata() to ensure the token is available
      // (refreshed if necessary).
      credentials.getRequestMetadata();

      AccessToken accessToken = credentials.getAccessToken();
      listener.onSuccess(wrapOAuthToken(accessToken, authVariable));
    } catch (Exception e) {
      listener.onError(e.toString());
    }
  }

  @Override
  public void addTokenChangeListener(TokenChangeListener listener) {
    CredentialsChangedListener listenerWrapper = new TokenChangeListenerWrapper(
        listener, executor, authVariable);
    credentials.addChangeListener(listenerWrapper);
  }

  private static String wrapOAuthToken(AccessToken result, Map authVariable) {
    if (result == null) {
      // This shouldn't happen in the actual production SDK, but can happen in tests.
      return null;
    }

    GAuthToken googleAuthToken = new GAuthToken(result.getTokenValue(), authVariable);
    return googleAuthToken.serializeToString();
  }

  /**
   * Wraps a TokenChangeListener instance inside a CredentialsChangedListener. Equality
   * comparisons are delegated to the TokenChangeListener so that listener addition and removal will
   * work as expected.
   */
  private static class TokenChangeListenerWrapper implements CredentialsChangedListener {

    private final TokenChangeListener listener;
    private final Executor executor;
    private final Map authVariable;

    TokenChangeListenerWrapper(
        TokenChangeListener listener,
        Executor executor,
        Map authVariable) {
      this.listener = checkNotNull(listener, "Listener must not be null");
      this.executor = checkNotNull(executor, "Executor must not be null");
      this.authVariable = authVariable;
    }

    @Override
    public void onChanged(OAuth2Credentials credentials) throws IOException {
      // When this event fires, it is guaranteed that credentials.getAccessToken() will return a
      // valid OAuth2 token.
      final AccessToken accessToken = credentials.getAccessToken();

      // Notify the TokenChangeListener on database's thread pool to make sure that
      // all database work happens on database worker threads.
      executor.execute(
          new Runnable() {
            @Override
            public void run() {
              listener.onTokenChange(wrapOAuthToken(accessToken, authVariable));
            }
          });
    }

    @Override
    public int hashCode() {
      return listener.hashCode();
    }

    @Override
    public boolean equals(Object obj) {
      return obj != null
          && obj instanceof TokenChangeListenerWrapper
          && ((TokenChangeListenerWrapper) obj).listener.equals(listener);
    }
  }
}