[1] Lab setup and initial app exploration

Initial exploratory steps including booting up emulator, launching our target app,

First things first, boot up your Android Emulator of choice. Please also ensure you have root and have ADB connectivity.

Install and configure the Photo Vault app

You only need to install Photo Vault if you are starting with your own emulator. If you've imported the lab image, you can skip to Launch the Photo Vault App.

Steps are shown in this video:

The method of installing an APK varies from emulator to emulator:

• Some emulators allow you to drag-and-drop APK files directly from the host to commence installation.

• Others, you will need to use adb to push or sideload. If you push, you can open them with File Manager.

• You can also choose to download directly from the Google Play store if your emulator supports it.

Once installed, launch the app. You will be immediately be prompted to set a PIN.

Enter and confirm a PIN. Now you need to import media or use the virtual camera (if available) to capture some data for testing purposes.

Click on the Main Album and press on the plus button. If your emulator supports it, you can use the Camera app to take a photo in a virtual room.

Great, you now have some test data to work with for our lab.

Launch the Photo Vault app

To launch the app, click and hold the mouse in the bottom-center area of the emulator screen, then drag your cursor upward to reveal the app menu which includes installed applications.

Find ‘Photo Vault’ on the list of installed apps and open it.

You will now see the ‘Enter Passcode’ screen, as shown below.

So, when you open the app, the very first thing you are presented with a numeric PIN pad. The correct 4 digit numeric PIN is required to proceed.

Even without programming background, thinking about it logically we might estimate that somewhere in our app's logic, there is probably a function whose sole purpose in life is to check to see whether an inputted PIN is correct or not.