Emulate a radius server in .NET

Question

We have a wireless controller that prompts client machines for a username and pass using radius, the wireless controller than relays that request to us, where we need to then send that request to a third party unencrypted.

1. is it possible to emulate a radius server in .net is there an api.
2. is there a radius encryption algo short of clear text that allows for decryption with a shared key between my app server and the wireless controller.
3. anybody done this before?

Answer 1

RADIUS is just a network service protocol like any other so...

Question #1 - can you emulate a RADIUS server in .NET?

Yes absolutely. The protocol is documented in

RFC 2865 : Remote Authentication Dial In User Service

Create a server process that hosts a UDP listener that handles the protocol and gives appropriate responses.

Question #2 - shared-secret auth

MS-CHAP enabled a shared-secret challenges

Question #3 - done before?

Yes TekRADIUS was written in .NET so it is certainly possible.

http://www.tekradius.com/

I'd T-shirt size this as a large to extra-large problem if you were looking to create a complete solution. Compatibility is the biggest challenge to completeness - of course you may be able to scope down this problem.

Answer 2

It's a lot of work but yes you can do in .NET. Here are two links for you:

nRadius

TinyRadius (it's a java project, could be ported with some work...)

There are other library but huge (such as http://www.freeradius.net/), too much work!