Pantalaimon
Pantalaimon is a Matrix proxy that handles end-to-end encryption support.
Installation
It can be installed with the pantalaimon package, and the panctl command line tool is in the pantalaimon-ui package.
Quickstart
There are two ways pantalaimon can be used: the first is to allow a bot access to an encrypted room, and the second is allowing a human to use access an encrypted room with a client that doesn't support end to end encryption yet. This wiki page currently only cover the second use case.
First, create a config file for pantalaimon at ~/.config/pantalaimon/pantalaimon.conf:
[MyMatrixServer] Homeserver = https://matrix.myserver.xyz ListenAddress = localhost ListenPort = 8009
This is the minimal configuration file, but man 5 pantalaimon will allow you to explore the various options.
Then launch pantalaimon as your user. You can then control it through dbus using panctl.
You should then log in using your regular Matrix client using http://localhost:8009 as your server.