Authenticating a Steam user via UNET

UPDATE: The logic below works and I have it running successfully.

I'm going to betray my ignorance completely on this matter. I don't know what I'm doing at this point.

I want to use Steam as my authentication layer for a multi-user game. My app is on there, unreleased, but my server is a headless c̶h̶i̶c̶k̶e̶n̶ dedicated process which will likely end up on Digital Ocean or AWS.

My intention is:

• Client requests a secure token/ticket via ISteamUser::GetAuthSessionTicket
• Client connects, via UNET to server and passes the aforementioned ticket
• Use the ISteamUser Interface magic to find out extra details about the user
• On the server, use the Steam web API to validate token via ISteamUserAuth
• If client passes the check, proceed to instantiate them, grant chat privileges etc...
• If client fails, return some sort of error to them with useful feedback
• Everybody dance now

I could really use some advice regarding the correct approach here. If someone's done this before, just a *nod* is all I need.