Passing the Windows Authentication context from IIS to Python using FastCGI

Question

I've successfully setup a sample Flask app on Windows / IIS 10.0 using wfastcgi with Python 3.6 running under a Windows domain account.

Now I'm trying to pass the IIS Windows Authentication user information to my Flask app. I've enabled only Windows Authentication in IIS and my browser authenticates successfully.

How do I find out which user is accessing the site in WSGI? I've checked the environment variables and the HTTP headers without luck.

PHP seems to have a fastcgi.impersonate-Option, but there seems to be no pendant for Python.

Answer 1

You mentioned that you've checked the environment variables and the HTTP headers. If you checked the environment variables with os.environ.get['REMOTE-USER'] then you should receive an empty string because your Python instance is running locally on the server and is not remote. And unless you use something like ISAPI rewrite, IIS won't write the REMOTE-USER to the headers either.

The easiest solution is to check the environment variables that IIS explicitly passes to Flask:

from Flask import request

username = request.environ('REMOTE_USER')