I'm one of the HipChat developers and we are currently using as3crypto to enable secure connections in our AIR app. Unfortunately, development on as3crypto has essentially petered off into nothing. The owner of the project, Hurlant, seems to have stopped updating it completely, although there are still community members who post issues and help others fix issues.
We also attempted to use the SecureSocket class which became available in AIR 2, but 1) it has dubious Linux support (most of our Linux users couldn't connect anymore when we released an update using SecureSocket) and 2) it doesn't support a manual TLS upgrade of the connection (to be fair, as3crypto's TLSSocket doesn't either, but it was easy to modify the class to allow it).
It would be awesome if Adobe could at least provide some open-source development effort to the library, if not officially supporting it. Alternatively, a 'native' implementation using SecureSocket (or a separate TLSSocket class) would work too, but they would need to fix both the issues I mentioned above :/
