Chat

The university hosts a matrix server which can be used with the university internal credentials. This page gives a quick introduction on how to setup 'element', the reference implementation of the client. You can of course use other implementations (there are plenty) and similar steps probably apply to those as well. However, you are on your own! Also, element is by far the most feature complete as of now. You might want to consider that. For a list of other clients and general information about matrix check matrix.org.

There is also some information on the RRZE page.

The rest of the page describes the setup on our cluster, it should be similar on your laptop (if you choose to install it there too) but better consider also reading up instructions for your system.

First start of element

Element can be started like any other program, from the command line the simplest is to type element-desktop.

On first start you might be greeted with an error message about not finding save storage for secrets if so, this is already your first encounter with what makes the matrix system slightly more difficult than your off-the-shelf chat software. Here is the TLDR: Matrix is a distributed protocol, so no central authority. Therefore it is vital that every user can authenticate themself to a server and, more importantly, authenticate any other user. This is done by encryption keys (if you encrypt your emails, the very same mechanism is used).

To store keys a keyring is used (something like a managed safe, also for login credentials, credit card information, etc.). And for some reason this keyring storage might not be found correctly. To give element a hint type in a terminal

element-desktop --password-store="gnome-libsecret"

This should greet you with a window as shown in the image.

After the first start the option --password-store is no longer required as it should be configured in your preferences now.

Login with FAU credentials

To login with your valid IdM account click on (you guessed it): Sign In. The next page asks you to specify a home server, to change it to the RRZE hosted server click on Edit and input matrix.fau.de in the opening window under Other homeserver. After hitting continue you should see this

By clicking on Continue with FAU IdM you will be forwarded to the IdM webpage. Login there to confirm your credentials and open elements from the drop-down (if it does not do it automatically).

Securing Key

Important: Do not skip this step or you might lose access to your messages!

With your newly activated account a secure key will be stored. This key represents you within the matrix network. If you lose this key you will have to create a different key which authenticates you. This has two consequences: All logins on other devices are reset (not so dramatic), and you will not be able to decrypt any messages that you (your previous you) send! Quite problematic. To help with this follow the steps prompted for. If they are not, click on the button in the top left corner (a letter for your initial). There select All settings and go to Encryption. The checkbox for Key storage should be checked and you can add a recovery key below. You will be asked for a password and a key will be shown. Both are independently able to recover your identity and should not be shared with anyone. So store them at a safe place.

Login on other device

When you login from another device you will likely get a message saying something along the lines of unverified identity. You can use the password form the key storage from the section above to set your identity, or you can use your already verified device. Simply follow the instructions on screen. You can also skip identifying, but this will not allow you to see encrypted messages that have been send to you, nor can you send encrypted messages (but not all chats are encrypted)!

Final steps

Explore! You can create private and groups chats and explore rooms. Of course you can also create your own rooms, with different visibility settings etc. For Remeisens a room exists here

LaTeX integration

One handy feature of elements is the ability to chat with latex commands. This is currently an experimental feature which needs to be enabled by hand. To do this create a file here ~/.config/Element/config.json which contains the following

{                                                                                                       
  "features": {                                                                                         
    "feature_latex_maths": true                                                                         
  }                                                                                                     
}

After restarting element-desktop you can type things like $E = mc^2$ and they will appear nicely typeset.

Some more information

If you want to know more about matrix and why and how it does things you might find this beginner friendly introduction interesting: joinmatrix.

Joining rooms outside and let others join your rooms

You can join (public) rooms on other servers by searching them. There is a small drop-down menu that allows you to change other servers and search by names. In the same menu you can also add other external servers, this is relevant if you want to join groups hosted in other university networks.

For users outside of FAU to join and where their network does not provide a matrix instance it is simplest to join matrix.org and register there. Just make sure that when you create a room which is meant to be accessed by someone from the outside this access is not restricted (under the advanced settings of the room creation dialog).

That's it, happy chatting :)