Updating STSProfile ServiceURL for Azure National Cloud using Username and Password Credentials

[ntomczek]

I've been working on pulling SharePoint data and ran into an issue with Azure National Cloud. I am currently limited to username and password to connect.

Currently when the STSProfile class initializes it sets the serviceURL to 'https://login.microsoftonline.com'. When the function _acquire_service_token in SamlTokenProvider.py is called it creates a new instance of of STSProflie and pulls the _sts_profile.security_token_service_url which will always point to Pub cloud. This results in the following error:

AADSTS90038: Tenant '<tenant>' request is being redirected to the National Cloud

If I manually change the serviceURL to 'https://login.microsoftonline.us'. Everything works fine.

I have not been able to find a way to update the serviceURL to point to National Cloud via the ClientContext, RequestOptions or other means. Before I start working on alternative security methods, or a fix, I wanted to verify that I'm not missing an existing way to make this change.