U2F Android Application Development

Explain that first factor and other forms of second factor authentication is up to the developer as to how they want to implement it.

SurePassIdU2fSign

The Sign In Activity must extend SurePassIdU2fSignActivity. It must implement the following abstract methods.


public interface Listener {

/**
 * Method used to go to the target activity after U2F Sign succeeds.
 */
 void gotoTargetActivity();

/**
 * Method used to go to an activity that provides the user the ability
 * to use a different second factor method if they are unable to use
 * a U2F Authenticator.
 */
 void gotoAlternateVerificationActivity();

/**
 * Called if the U2F Sign operation was canceled by the user.
 */
 void u2fSignCanceled();

/**
 * Called if there was an error during the U2F Sign Operation.
 *
 * @param errorMessage The error that occurred.
 */
 void u2fSignError(CharSequence errorMessage);
}

SurePassIdU2fSign

public class DemoSignInActivity extends Activity implements SurePassIdU2fSign.Listener {

  private SurePassIdU2fSign mU2fSign;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    initUi();
    mU2fSign = new SurePassIdU2fSign(this, this);
  }

  void afterLoginSuccess(String username) {
    mU2fSign.u2fSign("https://u2f.server.com/example", username);
  }

  @Override
  public void onActivityResult(int requestCode, int resultCode, Intent intent) {
    mU2fSign.onActivityResult(requestCode, resultCode, intent);
  }

  @Override
  public void gotoTargetActivity() {
    Intent intent = new Intent(this, DemoAppActivity.class);
    startActivity(intent);
  }

  @Override
  public void gotoAlternateVerificationActivity() {
    Intent intent = new Intent(this, DemoEnterOtpActivity.class);
    startActivity(intent);
  }

  @Override
  public void u2fSignCanceled() {
    resetFormValues();
    enableForm();
    displayMessage("Sign In canceled.");
  }

  @Override
  public void u2fSignError(CharSequence errorMessage) {
    displayMessage(errorMessage);
    enableForm();
  }
}

Upon successfully authenticating the user it should call

protected void u2fSign(String username)

That method will perform all the necessary U2F operations.