com.google.firebase.auth.FirebaseAuthException: Firebase ID token isn't signed by a valid public key

Question

I am trying to verify Id Token sent by android client app on my java server using firebase admin sdk. I followed

Admin Sdk and Android

FirebaseOptions options = new FirebaseOptions.Builder()
    .setServiceAccount(sce.getServletContext().getResourceAsStream("/WEB-INF/serviceAccountKey.json"))
    .setDatabaseUrl("https://[project-id].firebaseio.com/")
    .build();
FirebaseApp.initializeApp(options);
FirebaseToken decodedToken = FirebaseAuth.getInstance().verifyIdTokenAsync(idToken).get();
    String uid = decodedToken.getUid();

Retrive ID token from Android client

mAuth.signInAnonymously()
            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
   @Override
   public void onComplete(@NonNull Task<AuthResult> task) {
       if (task.isSuccessful()) {
           final FirebaseUser user = mAuth.getCurrentUser();
           user.getIdToken(true).addOnCompleteListener(new OnCompleteListener<GetTokenResult>() {
               @Override
               public void onComplete(@NonNull Task<GetTokenResult> task) {
                   String token = task.getResult().getToken();
                   Log.e(TAG,"signInAnonymously:success :  onComplete : "+token);
                   callApi(token);
               }
           });

        } else {
            // If sign in fails, display a message to the user.
            Toast.makeText(SignIn.this, "Authentication failed.",
            Toast.LENGTH_SHORT).show();
        }

    }
});

Getting exception on server

com.google.firebase.auth.FirebaseAuthException: Firebase ID token isn't signed by a valid public key. See https://firebase.google.com/docs/auth/admin/verify-id-tokens for details on how to retrieve an ID token. at com.google.firebase.auth.internal.FirebaseTokenVerifier.verifyTokenAndSignature(FirebaseTokenVerifier.java:147) at com.google.firebase.auth.FirebaseAuth$2.call(FirebaseAuth.java:223) at com.google.firebase.auth.FirebaseAuth$2.call(FirebaseAuth.java:211) at com.google.firebase.tasks.Tasks$1.run(Tasks.java:82) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)

Answer 1

Can you try this code.(Just only delete the setDatabaseUrl if you that not use.)

FirebaseOptions options = new FirebaseOptions.Builder()
.setServiceAccount(sce.getServletContext().getResourceAsStream("/WEB-INF/serviceAccountKey.json"))
.build();