Obfuscate Xamarin Application

Question

Is it possible to extract the code of a Xamarin Android application and inspect it?

I am in last stages of one Application which would be soon released on Play Store. However, I am worried if the code could be extracted and looked at by other people.

Please advise, how to secure my App from other people looking at the code for it.

Answer 1

Yes, it is possible to extract the code of a Xamarin.Android application. By default, the .dll files are just resources inside the APK, and they can be extracted with a zip utility and examined with e.g. ILSpy.

The Xamarin docs explain how to protect your application, including:

1. Disable debugging
2. Obfuscate with Dotfuscator
3. Bundle assemblies into native code (but see below)
4. Use AOT (native) compilation (but see below)

Note that #3 requires an Enterprise license and just puts the .NET .dlls a layer deeper in the APK; it is still possible to extract them and they are still unobfuscated.

Note that #4 is explicitly listed as an experimental feature that should not be used in production.

Full disclosure: I work for PreEmptive Solutions, and we make Dotfuscator.