Which files would need to be edited to hide the username and password box for Crowd?

[Gaven Ray]

I know this seems like a silly request.

Let me give some backstory. We had an incident with our Confluence system and now our Cyber team wants us to disable the username and password boxes from all of our Atlassian products. We have a method of doing that for Jira and Confluence. 

I can't seem to find where we would or even if it is possible to hide the username and password box, change the name of the log in page, or any option to make it so users can't log in to Crowd. I can have the firewall changed so it is only available on our network which would be a minor thing. 

I would love to make it so only an admin could login to Crowd by knowing the exact URL as well as have it only available on our network.

Is this possible and which files would I need to change?