Microsoft's .NET platform is a wonderful development environment. However the ease with which your compiled assemblies can be decompiled, using tools such as .NET Reflector, is disturbing if you value your Intellectual Property. Infralution .NET Encryptor provides a solution to this problem that includes the following features:
- Protects executable and library assemblies compiled using VB.NET and C#
- Support for x86, x64 and AnyCPU applications
- Compresses assemblies so that the resultant executable is smaller and loads faster
- Allows you to combine multiple assemblies into a single executable
- Encryption/Decryption algorithms implemented in native x86/x64 code
- Fully customizable managed bootstrapper program (in VB.NET or C#)
- Easy integration into your build process
- Optional integrated Splash screen while your application is loading
- Anti-debug and anti-dumping protection
How does it work?
.NET Encryptor encrypts your application assemblies using your own unique strong name. The encrypted assemblies are added as embedded resources to a small "bootstrap" application project (written in VB.NET or C#). The bootstrap application displays a splash screen and calls the AssemblyLoaderx86 or AssemblyLoaderx64 DLL to decrypt and execute the main assembly of your application. The "bootstrap" project builds the application executable that you distribute to your customers. You can fully customize the assembly attributes (version, icon, name etc) and splash screen of the bootstrap application to match your requirements. The encryption process can be fully automated by adding a "Pre-build" event to the bootstrap project that calls NetEncryptor.exe to encrypt each of the application assemblies. The sample projects demonstrate this technique.
How is it different to other code protection products?
Unlike obfuscators and some protectors .NET Encryptor does not modify your assemblies. It encrypts them and then decrypts and loads them dynamically when your application is run. A major issue with obfuscators and other protectors is that code that relies on .NET Reflection (as much data binding and serialization code does) will often not work correctly or behave differently when protected. This means that often bugs will only show up after the code has been protected. Because the code is obfuscated/protected this can make debugging the source of the problem very difficult.
Many code protection products wrap your .NET assemblies up into a native Win32 bootstrap application. While this can seem like a good thing it actually has the potential to cause problems because the entry .NET assembly (returned by Assembly.GetEntryAssembly) may be null or not associated with a file location. This can cause code that relies on this (such as settings code or control licensing) to fail when the code is protected. Another issue with this approach is that you can not compile a single AnyCPU application that will run on both Win32 and Win64 platforms in the appropriate mode (ie 32 bit on Win32 platforms and 64 bit on Win64 platforms). Many protectors don't even support managed x64 applications at all. The entry point for .NET Encryptor applications is a small bootstrap assembly written in either VB.NET or C#. You can fully customize this bootstrap assembly as required for your application. You can create x86 specific applications (that will also run on Win64 platforms using WOW64), x64 specific applications or Any CPU applications.
When evaluating code protection software it is important to try it on your real application. Some code protection products that work well on small sample projects can cause major issues when used for real, complex applications that use data binding, serialization or reflection. In particular you should consider how the product handles error reporting. If you are using an obfuscator then, unless it provides a stack decryption mechanism, the stack trace will be meaningless.
