We want to use a vendor server that is a logging repository. It doesn't require any authentication to connect to though. The client can see all the application logs by connecting to it, production at that. Yet we want developers to be able to see production logs.... This is a client (log viewer) that connects over tcp to the central logging server.... how an we add authentication to this ontop of the existing vendor software? Is there a way to add some kind of connecting authentication (without the vendor modifying the software of course).
Your question is very similar question to this one:
How would you send syslog securely over the public Internet?
Disclaimer: I wrote the accepted answer but I believe the same answer applies almost perfectly.
You may encapsulate the traffic in SSL with Stunnel and use a mutual authentification scheme.
EDIT: Website seems to be down, here's a link for downloading stunnel.