Can some hack my key license system by analysing my CLR DLLs?

Question

My software (written in C#/.NET) have a simple key license system to activate certain resources. The way it works is: it creates a unique code based on the running computer's hardware, then mix this value with the client's activated licenses to create a password that will, on that specific computer, liberate access to the determinated resources. The key given to the client is a file with the password.

The way it verifies this is even simpler: the software calculates the expected password, and then matches with the password stored on the file. If it matches, the resources are liberated.

So, since the software itself calculates the correct password, I wonder if it's possible to someone take the software's DLLs and hack them to discover the calculation method.

Answer 1

Yes, and if you don't put effort in to obfuscating your code it is trivial to do.

There will always be ways to get around any protection you put in place, the only thing you can do is make it difficult enough that any attacker will get too frustrated and declare it is not worth his time to try and reverse engeneer your software. It is just a matter of how much time/money is it worth it to you to keep that one extra person from trying.

I wrote a fairly extensive answer to a similar question here that goes over what steps you can do to mitigate the problem, but there is nothing you can do to stop it.