[Samba] automatically authenticate domain logged-on users in apache with AD/NTDOM?

[Palle Girgensohn]

Hi!

I don't use MS products at all, so I have very little knowledge with them, 
but I believe Microsoft has as protocol where Internet Explorer can 
automatically authenticate against an IIS server, and given that the server 
and client are on the same NT domain, and the client user is logged in to 
that domain, the user is automatically logged in without the need to give 
away the password one more time to the webserver.

What is happening between the web server & the web client? Is the protocol 
open or reverse engineered? Can this authentication be done using apache @ 
unix (perhaps by apache interacting with samba somehow)?

Any ideas or links to more info about this would be much appreciated. 
Thanks!

/Palle