[Android] Callbacks in MainActivity do not get analyzed

[AnakinRaW]

Consider the following app code

with MainActivity.java

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void onClick(View view){
        try {
            Cipher c = Cipher.getInstance("DES");
            c.doFinal();
        }
       catch (Exception e){
       }
    }
}

and activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onClick"
        android:text="Button" />

</androidx.constraintlayout.widget.ConstraintLayout>

Analyzing the code is done as follows:

CogniCryptAndroidAnalysis analysis = new CogniCryptAndroidAnalysis(apkPath, platformPath, rulesPath, Collections.EMPTY_LIST);
Collection<AbstractError> errors = analysis.run();
Assert.assertTrue(errors.size() >  0);

The test fails as CryptoAnalysis is unable to find any misuses. My guess is that the error is somewhere in the FlowDroid configuration which is done in CogniCryptAndroidAnalysis.
Reason for the error (probably) is because onClick() is nowhere connected to the onCreate() method (which is the virtual main() for android apps). Thus the constructed callgraph does not contain the button callback and CryptoAnalysis is unable to check rules against the onCreate() method.

As far as i understand the FlowDroid documentation it should be able to get it working, however i was not able to find the relevant code pieces yet.

[AnakinRaW]

branch with fix development: https://github.com/CROSSINGTUD/CryptoAnalysis/tree/androidCallbackFix