A fully working CLIPSP.SYS decrypter! Written in rust of course 
https://github.com/are-we-cool-yet/declipt
I'm going to write a blog post about it with some other people soon.
#`CLIPSP.SYS` Decryption
2 messages · Page 1 of 1 (latest)
For context, CLIPSP.SYS is the Windows kernel driver used in licensing and genuine activation. Like some other Windows kernel drivers, it uses Warbird encryption; however, CLIPSP.SYS is special with regards to its encryption because it implements a copy of FeistelDecrypt inside itself. Using various techniques and a little outside help, I was able to emulate a kernel-mode environment in user-mode and call the necessary functions for decryption, saving the decrypted memory to disk.
mavlevin
When reversing or fuzzing an executable, being able to run an arbitrary function with controlled data is extremely helpful. A dll (Dynamic Linked Library) with our target function would allow us to conveniently review and test the function as we wish. The only problem is that usually the function we want to examine resides in an exe, not a dll. ...
Official x64dbg blog!