I am trying to implement NTLM authentication on one of our internal sites and everything is working. The one piece of the puzzle I do not have is how to take the information from NTLM and authenticate with Active Directory.

There is a good description of NTLM and the encryption used for the passwords, which I used to implement this, but I am not sure of how to verify if the user's password is valid.

I am using Coldfusion but a solution to this problem can be in any language (Java, Python, PHP, etc).

Edit:

I am using Coldfusion on Redhat Enterprise Linux. Unfortunately we cannot use IIS to manage this and instead have to write or use a 3rd party tool for this.