.net - How to write an NTLM Authentication Module? -

I have to write an authentication module for IIS7, which actually behaves like NTLM, but does some additional checks module Active NTLM against the directory (hence the module knows that the user is OK) and then finally need to call any other service to verify.

I have to do this in an authentication module because the content on the actual IIS website is served through a custom IIS module which is a black box for me and I can not modify the client because it is black There is also a box. Apart from this, I can not use Windows Security Groups because I have a user database of my own according to the need to call.

I have received this article about writing, but I do not know how I user Active Directory / Windows.

Does anyone know how I can implement NTLM? IIS does not have to be centric, my problem is more "What do I get from the client's browser and how do I verify it?"

The description that you are describing does not sound like an authentication provider, it seems that you I would like to write authorization request for that authorization provider and I will use HttpContext.User which will already be a valid Windows authentication token (assuming you enable Windows authentication). At that time you get additional data from ActiveDirectory to get additional data or to get the system. You can use IsUserInRole and other APIs to access directory services. Just make sure that you can do some caching after going to AD for each single request, there may be a display problem. At least IIS handles Windows Auth for you that cache.