Taking IM Back Using Prosody

The common way for most people to chat is using an app on their phone which typically one of Whatsapp, Messenger or Telegram. In the same vein we have apps like Threema and Signal which are more popular in certain circles. But the one consistent feature for all these services, is the centralization of accounts and forcing users to be trapped inside a silo. It is true whether the services or clients themselves are open source or not. In the case of Signal, the author doesn’t want to federate with people who want to run their own servers¹. Given that the Freedom of the Press Foundation recommends Signal as a secure communications tool², I have nothing against the security of the service and the client. It has audited by cryptographers and the underlying protocol for end-to-end encryption is used by other messaging services. Given this, you would still want to have control over the service and client for various reasons including not wanting to be dependent on centralized services.

XMPP

XMPP is an open standard for messaging. Notably GTalk and earlier iterations of Messenger supported XMPP and used to federate with other servers. So, it has a proven track record of actually working at scale but being closed off to grow their own proprietary services and lock users into such platforms. XMPP is generally extended by XEPs, XMPP Extension Protocols, that include features such as end-to-end encryption, file uploads, avatars etc. Even the definition of the process XEPs is XEP-0001 :)

To use XMPP, one can sign up for an account at one of the free services which need to be verified or you can run your own server.

Prosody

Prosody is an XMPP server that implements a lot of XEPs³ and further has community modules which can be used just as easily⁴. I will be using Debian 9 on the server and the project provides repositories for installing the latest stable release to make installation simple.

To install start by adding their repository to Debian’s sources list,

# /etc/apt/sources.list.d/prosody.list
deb https://packages.prosody.im/debian stretch main

add their key

wget https://prosody.im/files/prosody-debian-packages.key -O- | sudo apt-key add -

and finally install the package using apt,

sudo apt update && sudo apt install prosody

Configuring Prosody

The configuration of Prosody is a single Lua file located in /etc/prosody/prosody.cfg.lua. If you are already configuring this on server, the first course of action is to change the domain under which you want to run the server.

VirtualHost "myxmppserver.im"

Next is to specify the certificate used for SSL,

https_certificate = "/etc/prosody/certs/myxmppserver.im.crt"

I use Lets Encrypt to obtain certificates for free and if you already use for the server, it can be linked to the current location.

sudo prosodyctl --root cert import /etc/letsencrypt/live

At this point you can start the server using systemctl,

sudo systemctl start prosody

By default it will log under /var/logs/prosody/, so be sure to check there in case there are issues. To test the installation, you need to add an account. By default, the configuration prevents creating accounts by using clients as a safety feature but if you are planning to run a public server this can changed later.

sudo prosodyctl adduser test@myxmppserver.im

Test the account using a Jabber client. There are many programs but I find the android app Conversations, to be fully featured and a pleasure to use. If all is well, we can move on to enabling some nice to have features in Prosody.

In the modules_enabled table, uncomment mam and csi_simple. mam allows one to access the archive and this allows Conversations to pull down the history when you were offline. For using some community modules, it was recommended by linkmauve to have a clone of the modules repository and link the required modules into modules library under prosody.

hg clone https://hg.prosody.im/prosody-modules/ prosody-modules
sudo ln -s ~/prosody-modules/mod_smacks/mod_smacks.lua /usr/lib/prosody/modules

You can link these modules as required. To enable them, add the module to the modules_enabled table and restart the server. You can check for compliance of your server on https://compliance.conversations.im/ which can be useful to see if you want to enable other modules according to your requirements. Please remember to create a separate account to run these tests by using prosodyctl since you will have to provide passwords to the compliance site.

In conclusion, one can run their own XMPP server or use a trusted server, for example, https://jabberfr.org/ and chat with anyone on XMPP whether on your server or on their own islands. You can meet me at xmpp:jagan@j605.tk, See ya :)