You can let your users authenticate with Firebase using their GitHub accounts by integrating GitHub authentication into your app.
Before you begin
- Add Firebase to your Android project.
- If you haven't yet connected your app to your Firebase project, do so from the Firebase console.
- Add the dependency for Firebase Authentication to your app-level
build.gradle
file:compile 'com.google.firebase:firebase-auth:9.6.1'
- Register your app as a developer application on GitHub and get your app's OAuth 2.0 Client ID and Client Secret.
- Enable GitHub authentication:
- In the Firebase console, open the Auth section.
- On the Sign in method tab, enable the GitHub sign-in method and specify the OAuth 2.0 Client ID and Client Secret you got from GitHub.
- Then, make sure your Firebase OAuth redirect URI (e.g.
my-app-12345.firebaseapp.com/__/auth/handler
) is set as your Authorization callback URL in your app's settings page on your GitHub app's config.
Authenticate with Firebase
- Integrate GitHub authentication into your app by following the developer's documentation. Use the web application flow, and set up an intent filter in your app to handle the OAuth 2.0 callback from GitHub. At the end of the GitHub sign-in flow, you will receive an OAuth 2.0 access token.
- In your sign-in activity's
onCreate
method, get the shared instance of theFirebaseAuth
object:private FirebaseAuth mAuth; // ... // Initialize Firebase Auth mAuth = FirebaseAuth.getInstance();
- Set up an
AuthStateListener
that responds to changes in the user's sign-in state:private FirebaseAuth.AuthStateListener mAuthListener; // ... @Override protected void onCreate(Bundle savedInstanceState) { // ... mAuthListener = new FirebaseAuth.AuthStateListener() { @Override public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) { FirebaseUser user = firebaseAuth.getCurrentUser(); if (user != null) { // User is signed in Log.d(TAG, "onAuthStateChanged:signed_in:" + user.getUid()); } else { // User is signed out Log.d(TAG, "onAuthStateChanged:signed_out"); } // ... } }; // ... } @Override public void onStart() { super.onStart(); mAuth.addAuthStateListener(mAuthListener); } @Override public void onStop() { super.onStop(); if (mAuthListener != null) { mAuth.removeAuthStateListener(mAuthListener); } }
- After a user successfully signs in with GitHub, exchange the OAuth 2.0
access token for a Firebase credential, and authenticate with Firebase using
the Firebase credential:
String token = "<GITHUB-ACCESS-TOKEN>"; AuthCredential credential = GithubAuthProvider.getCredential(token); mAuth.signInWithCredential(credential) .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() { @Override public void onComplete(@NonNull Task<AuthResult> task) { Log.d(TAG, "signInWithCredential:onComplete:" + task.isSuccessful()); // If sign in fails, display a message to the user. If sign in succeeds // the auth state listener will be notified and logic to handle the // signed in user can be handled in the listener. if (!task.isSuccessful()) { Log.w(TAG, "signInWithCredential", task.getException()); Toast.makeText(MainActivity.this, "Authentication failed.", Toast.LENGTH_SHORT).show(); } // ... } });
If the call tosignInWithCredential
succeeds, theAuthStateListener
runs theonAuthStateChanged
callback. In the callback, you can use thegetCurrentUser
method to get the user's account data.
Next steps
After a user signs in for the first time, a new user account is created and linked to the credentials—that is, the user name and password, or auth provider information—the user signed in with. This new account is stored as part of your Firebase project, and can be used to identify a user across every app in your project, regardless of how the user signs in.
-
In your apps, you can get the user's basic profile information from the
FirebaseUser
object. See Manage Users. In your Firebase Realtime Database and Firebase Storage Security Rules, you can get the signed-in user's unique user ID from the
auth
variable, and use it to control what data a user can access.
You can allow users to sign in to your app using multiple authentication providers by linking auth provider credentials to an existing user account.
To sign out a user, call
signOut
:
FirebaseAuth.getInstance().signOut();