'Not found' error on callback URL in Android app

konrad.sopala · July 26, 2023, 1:44pm

Problem statement

I’m trying to get Auth0 working in my Android app, but when I log in I see a ‘Not found’ message in the top left corner of an otherwise blank page.

Cause

The URL of this error page is the callback URL included in the allowed callback list as per the instructions, however it is using the https scheme and not a custom scheme for mobile. Mobile browsers tend to block redirects when using an https scheme leading to a “Not found” page.

Solution

Instead of using an https scheme in the callback URL, any custom scheme that is not http or https should work. A unique scheme would be ideal.

For example, if you were to use a custom scheme like “demo://” used in our Android quickstart, you would then want to check you application code to make sure you have “.withScheme(“demo”)” set within login functions as shown here:

github.com

auth0-samples/auth0-android-sample/blob/4007ccb2376c0cda10f6aee0698aee5d89145c64/00-Login/app/src/main/java/com/auth0/samples/LoginActivity.java#L47


      
              auth0 = new Auth0(this);
          
              //Check if the activity was launched to log the user out
              if (getIntent().getBooleanExtra(EXTRA_CLEAR_CREDENTIALS, false)) {
                  logout();
              }
          }
          
          private void login() {
              WebAuthProvider.login(auth0)
                      .withScheme("demo")
                      .withAudience(String.format("https://%s/userinfo", getString(R.string.com_auth0_domain)))
                      .start(this, new Callback<Credentials, AuthenticationException>() {
          
                          @Override
                          public void onFailure(@NonNull final AuthenticationException exception) {
                              Toast.makeText(LoginActivity.this, "Error: " + exception.getMessage(), Toast.LENGTH_SHORT).show();
                          }
          
                          @Override
                          public void onSuccess(@Nullable final Credentials credentials) {

Also be sure to include “” in the AndroidManifest.xml set here:

github.com

auth0-samples/auth0-android-sample/blob/4007ccb2376c0cda10f6aee0698aee5d89145c64/00-Login/app/src/main/AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.auth0.samples">

    <uses-permission android:name="android.permission.INTERNET"/>

    <application
            android:allowBackup="true"
            android:icon="@mipmap/ic_launcher"
            android:label="@string/app_name"
            android:roundIcon="@mipmap/ic_launcher_round"
            android:supportsRtl="true"
            android:theme="@style/AppTheme">
        <activity android:name=".LoginActivity" android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <activity android:name=".MainActivity"/>

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General setup instructions can be found here:

konrad.sopala · July 26, 2023, 1:44pm