Hash Password in C#? Bcrypt/PBKDF2

Question

I looked up msdn and other resources on how to do this but i came up with no clear solutions. This is the best i found http://blogs.msdn.com/b/shawnfa/archive/2004/04/14/generating-a-key-from-a-password.aspx?Redirected=true

I would like to hash passwords in C# using either bcrypt or PBKDF2 (which appears to be bcrypt related). I like to experiment with how many rounds it takes for my computer to hash a password. However everything seems to be about encrypting while everyone talks about hashing. I can't figure it out. How do i hash a password? It looks more like PBKDF2 (Rfc2898?) is a random number generator and i use GetBytes(amount) to choose how big my hash size is.

I'm confused. How exactly do i hash a password with bcrypt/PBKDF?

Answer 1

PBKDF2

You were really close actually. The link you have given shows you how you can call the Rfc2898DeriveBytes function to get PBKDF2 hash results. However, you were thrown off by the fact that the example was using the derived key for encryption purposes (the original motivation for PBKDF1 and 2 was to create "key" derivation functions suitable for using as encryption keys). Of course, we don't want to use the output for encryption but as a hash on its own.

You can try the SimpleCrypto.Net library written for exactly this purpose if you want PBKDF2. If you look at the implementation, you can see that it is actually just a thin wrapper around (you guessed it) Rfc2898DeriveBytes.

BCrypt

You can try the C# implementation named (what else) BCrypt.NET if you want to experiment with this variant.

Disclaimer: I have not used or tested any of the libraries that I have linked to... YMMV