License key library for C# windows application that is open source / free [closed]

Question

Any recommendations for an open source (free) C# library/application for a C# Windows Application that could be used for: (a) creating license/product keys and (b) has library that can be used within the code to perform a check to see whether the entered license key is valid?

(I've seen other posts which cover commercial products, but here I'm looking for a ready-to-go tool with library that can be used in a C# windows application)

Answer 1

The .NET framework has a built-in licensing model (MSDN).

See also Applications Licensing using the .NET Framework on Developer.com

Answer 2

What about rhino-licensing? Here is an introductory license: Rhino Licensing