How can a signed application use an unsigned assembly (which can be regenerated at customer sites)

Question

My C# .net executable needs to be signed in order to use one of the methods in another of our assemblies that provides access to a password.

That same executable needs to reference and use an assembly that is not signed. The reason it is not signed is we provide a way for customers to regenerate it on site (it wraps access to modelled customizations in the app).

Is there any way the single executable can make use of both the signed and unsigned assemblies?

Answer 1

You can't reference unsigned assembly from signed assembly, but you can easily Load one using one of Assembly.Load methods.

Usually you provide interface (or base class if you like) in signed assembly and use that throughout code to obtain information at compile time. Customer's unsigned assembly (plugin) implements that interface on some specially marked class. Than your application loads the assembly (either from default location via Load, or from specified file via LoadFile), finds and constructs the class than uses it to obtain information at run-time.

Note: You may also look into "how to implement plugins in C#/.Net" questions for approaches.

Answer 2

I believe the only way for you to use an unsigned assembly is to load it at runtime using reflection.

You cannot a add strong name to your executable if it references something which is not strongly named.