Send Notification to specific RDP user from a WTS app that runs as a Windows service

Question

I am trying to send a user a message from a C++ app that runs as a service on a WTS server.

Multiple users are logged in via RDP, so I just want to send User X a notification.

I have done this using WTSSendMessage(). I am just looking for a more modern elegant method.

Any suggestions?

Answer 1

The usual approach is to run a GUI app in each user session, launched during login (it's possible for the service to spawn this but much simpler to use any of the conventional autorun techniques) and have it connect to the service via interprocess communication (named pipe is very common).

The service can impersonate the named pipe client in order to securely determine the associated user (unlike having the client simply report its username through the pipe) and then maintain a table of user IDs to pipe connections which it can use to deliver notifications.