Susam's IRC Pages

Soju User Delete Hash

2026-02-14T00:00:00Z

In my last post, I talked about switching from ZNC to Soju as my IRC bouncer. One thing that caught my attention while creating and deleting Soju users was that the delete command asks for a confirmation, like so:

$ sudo sojuctl user delete soju
To confirm user deletion, send "user delete soju 4664cd"
$ sudo sojuctl user delete soju 4664cd
deleted user "soju"

That confirmation token for a specific user never changes, no matter how many times we create or delete it. The confirmation token is not saved in the Soju database, as can be confirmed here:

$ sudo sqlite3 -table /var/lib/soju/main.db 'SELECT * FROM User'
+----+----------+--------------------------------------------------------------+-------+----------+------+--------------------------+---------+--------------------------+--------------+
| id | username |                           password                           | admin | realname | nick |        created_at        | enabled | downstream_interacted_at | max_networks |
+----+----------+--------------------------------------------------------------+-------+----------+------+--------------------------+---------+--------------------------+--------------+
| 1  | soju     | $2a$10$yRj/oYlR2Zwd8YQxZPuAQuNo2j7FVJWeNdIAHF2MinYkKLmBjtf0y | 0     |          |      | 2026-02-16T13:49:46.119Z | 1       |                          | -1           |
+----+----------+--------------------------------------------------------------+-------+----------+------+--------------------------+---------+--------------------------+--------------+

Surely, then, the confirmation token is derived from the user definition? Yes, indeed it is. This can be confirmed at the source code here. Quoting the most relevant part from the source code:

hashBytes := sha1.Sum([]byte(username))
hash := fmt.Sprintf("%x", hashBytes[0:3])

Indeed if we compute the same hash ourselves, we get the same token:

$ printf soju | sha1sum | head -c6
4664cd

This allows us to automate the two step Soju user deletion process in a single command:

sudo sojuctl user delete soju "$(printf soju | sha1sum | head -c6)"

But of course, the implementation of the confirmation token may change in future and Soju helpfully outputs the deletion command with the confirmation token when we first invoke it without the token, so it is perhaps more prudent to just take that output and feed it back to Soju, like so:

sudo sojuctl $(sudo sojuctl user delete soju | sed 's/.*"\(.*\)"/\1/')

Read on website | #shell | #irc | #technology | #how-to

From ZNC to Soju

2026-02-12T00:00:00Z

I have recently switched from ZNC to Soju as my IRC bouncer and I am already quite pleased with it. I usually run my bouncer on a Debian machine, where Soju is well packaged and runs smoothly right after installation. By contrast, the ZNC package included with Debian 13 (Trixie) and earlier fails to start after installation because of a missing configuration file. As a result, I was forced to maintain my own configuration file along with a necessary PEM bundle, copy them to the Debian system and carefully set the correct file permissions before I could run ZNC successfully. None of this is necessary with Soju, since installing it from the Debian package repository automatically sets up the configuration and certificate files. I no longer have to manage any configuration or certificate files myself.

Setup

It is quite straightforward to install and set up Soju on Debian. The following two commands install Soju:

sudo apt-get update
sudo apt-get -y install soju

Then setting up an IRC connection involves another two commands:

sudo sojuctl user create -username soju -password YOUR_SOJU_PASSWORD
sudo sojuctl user run soju network create -name bnc1 -addr irc.libera.chat -nick YOUR_NICK -pass YOUR_NICK_PASSWORD

Here, YOUR_SOJU_PASSWORD is a placeholder for a new password you must choose for your Soju user. Finally, we restart Soju as follows:

sudo systemctl restart soju

Database

What previously involved maintaining several files that had to be installed and configured on each machine running ZNC is now reduced to the two sojuctl commands above. Still, the configuration needs to live somewhere. In fact, the two sojuctl commands introduce earlier store the configuration in a SQLite database. Here is a glimpse of what the database looks like:

$ sudo sqlite3 /var/lib/soju/main.db '.tables'
Channel              MessageFTS_data      ReadReceipt
DeliveryReceipt      MessageFTS_docsize   User
Message              MessageFTS_idx       WebPushConfig
MessageFTS           MessageTarget        WebPushSubscription
MessageFTS_config    Network
$ sudo sqlite3 /var/lib/soju/main.db 'SELECT * from User'
1|soju|$2a$10$mM5Qcz8.OPMi9lyWDxPRh.bNxzq7jtLdxcoPl09AYTnqcmLmEqzSO|0|||2026-02-17T23:24:24.926Z|1||-1
$ sudo sqlite3 /var/lib/soju/main.db 'SELECT * from Network'
1|bnc1|1|irc.libera.chat|YOUR_NICK||||YOUR_NICK_PASSWORD|||||||1|1

Client Configuration

Finally, the IRC client can be configured to connect to port 6697 on the system running Soju. Here is an example of how this can be done in Irssi:

/network add -nick YOUR_NICK -user soju/bnc1 net1
/server add -tls -network bnc1 YOUR_SOJU_HOST 6697 YOUR_SOJU_PASSWORD
/connect net1

You can also set up multiple connections to IRC networks through the same Soju instance. All you need to do is repeat the sojuctl commands to create additional networks such as bnc2, bnc3 and so on, then repeat the configuration in your IRC client using new network names such as net2, net3, etc. These network names are entirely user defined, so you can choose any names you like. The names bnc2, net2 and so on are only examples.

Read on website | #irc | #technology | #how-to

Simplicity of IRC

2022-01-09T00:00:00Z

During discussions with my friends and colleagues, whenever the topic of chat protocols comes up, I often remark how simple the Internet Relay Chat (IRC) protocol is and how this simplicity has fostered creativity in the lives of many young computer hobbyists growing up in the late 1990s and early 2000s. For many of us who were introduced to the Internet during that time, writing an IRC bot turned out to be one of our first few non-trivial hobby programming projects that involved network sockets, did something meaningful and served actual users.

Simplicity

The underlying payloads that IRC servers and clients exchange during an IRC session are quite simple to read manually and understand. While implementing IRC servers still involves significant work to keep track of users and channels as well as exchanging network state and messages between servers, implementing IRC clients can often be quite simple. With a convenient programming language, one can develop all kinds of fun tools and bots pretty quickly. Only creativity is the limit!

In the early days of IRC, it was quite common for someone with basic programming skills to write a simple IRC bot within a matter of hours. Such IRC bots typically responded to requests from users, answered frequently asked questions, hosted trivia quiz, etc. The simplicity of the protocol made it very enticing to write programs that could talk to IRC servers directly. In fact, many people chose to write the code to parse and create IRC payloads from scratch. Observing the TCP/IP packets with a packet analyser such as Wireshark or Tcpdump was all one needed to learn about the various payload formats. Additionally, back then RFC 1459 served as a good reference to learn the IRC specification.

As a result of the simplicity of the IRC protocol, sometimes when I wanted to join an IRC channel, say to seek some technical help, from a system without an IRC client installed, I would often just start a telnet, nc or openssl connection directly to my favourite IRC network and type out IRC protocol commands by hand to join channels and talk to users.

Session

To illustrate how simple the IRC protocol is, here is an example of a minimal IRC session that involves joining a channel and posting a message:

$ nc irc.libera.chat 6667
:strontium.libera.chat NOTICE * :*** Checking Ident
:strontium.libera.chat NOTICE * :*** Looking up your hostname...
:strontium.libera.chat NOTICE * :*** Couldn't look up your hostname
:strontium.libera.chat NOTICE * :*** No Ident response
NICK humpty
USER humpty humpty irc.libera.chat :Humpty Dumpty
:strontium.libera.chat 001 humpty :Welcome to the Libera.Chat Internet Relay Chat Network humpty
:strontium.libera.chat 002 humpty :Your host is strontium.libera.chat[204.225.96.123/6667], running version solanum-1.0-dev
:strontium.libera.chat 003 humpty :This server was created Sat Oct 30 2021 at 17:56:22 UTC
:strontium.libera.chat 004 humpty strontium.libera.chat solanum-1.0-dev DGQRSZaghilopsuwz CFILMPQSTbcefgijklmnopqrstuvz bkloveqjfI
:strontium.libera.chat 005 humpty MONITOR=100 CALLERID=g WHOX FNC ETRACE KNOCK SAFELIST ELIST=CMNTU CHANTYPES=# EXCEPTS INVEX CHANMODES=eIbq,k,flj,CFLMPQSTcgimnprstuz :are supported by this server
:strontium.libera.chat 005 humpty CHANLIMIT=#:250 PREFIX=(ov)@+ MAXLIST=bqeI:100 MODES=4 NETWORK=Libera.Chat STATUSMSG=@+ CASEMAPPING=rfc1459 NICKLEN=16 MAXNICKLEN=16 CHANNELLEN=50 TOPICLEN=390 DEAF=D :are supported by this server
:strontium.libera.chat 005 humpty TARGMAX=NAMES:1,LIST:1,KICK:1,WHOIS:1,PRIVMSG:4,NOTICE:4,ACCEPT:,MONITOR: EXTBAN=$,ajrxz :are supported by this server
:strontium.libera.chat 251 humpty :There are 66 users and 48644 invisible on 25 servers
:strontium.libera.chat 252 humpty 35 :IRC Operators online
:strontium.libera.chat 253 humpty 11 :unknown connection(s)
:strontium.libera.chat 254 humpty 21561 :channels formed
:strontium.libera.chat 255 humpty :I have 3117 clients and 1 servers
:strontium.libera.chat 265 humpty 3117 4559 :Current local users 3117, max 4559
:strontium.libera.chat 266 humpty 48710 50463 :Current global users 48710, max 50463
:strontium.libera.chat 250 humpty :Highest connection count: 4560 (4559 clients) (301752 connections received)
:strontium.libera.chat 375 humpty :- strontium.libera.chat Message of the Day -
:strontium.libera.chat 372 humpty :- Welcome to Libera Chat, the IRC network for
:strontium.libera.chat 372 humpty :- free & open-source software and peer directed projects.
:strontium.libera.chat 372 humpty :-
:strontium.libera.chat 372 humpty :- Use of Libera Chat is governed by our network policies.
:strontium.libera.chat 372 humpty :-
:strontium.libera.chat 372 humpty :- To reduce network abuses we perform open proxy checks
:strontium.libera.chat 372 humpty :- on hosts at connection time.
:strontium.libera.chat 372 humpty :-
:strontium.libera.chat 372 humpty :- Please visit us in #libera for questions and support.
:strontium.libera.chat 372 humpty :-
:strontium.libera.chat 372 humpty :- Website and documentation:  https://libera.chat
:strontium.libera.chat 372 humpty :- Webchat:                    https://web.libera.chat
:strontium.libera.chat 372 humpty :- Network policies:           https://libera.chat/policies
:strontium.libera.chat 372 humpty :- Email:                      support@libera.chat
:strontium.libera.chat 376 humpty :End of /MOTD command.
:humpty MODE humpty :+iw
JOIN #test
:humpty!~humpty@178.79.176.169 JOIN #test
:strontium.libera.chat 353 humpty = #test :humpty susam coolnickname ptl-tab edcragg
:strontium.libera.chat 366 humpty #test :End of /NAMES list.
PRIVMSG #test :Hello, World!
:susam!~susam@user/susam PRIVMSG #test :Hello, Humpty!
PART #test
:humpty!~humpty@178.79.176.169 PART #test
QUIT
:humpty!~humpty@178.79.176.169 QUIT :Client Quit
ERROR :Closing Link: 178.79.176.169 (Client Quit)

In the above session, the user connects to the Libera Chat network with the nickname humpty, joins a channel named #test and posts a message.

Note that the above session is not encrypted. By convention, IRC port 6667 is used for cleartext connections. A separate port, such as port 6697, is available for encrypted connections. Here is an example of an encrypted IRC session established with the OpenSSL command line tool:

$ openssl s_client -quiet -connect irc.libera.chat:6697 2> /dev/null
:strontium.libera.chat NOTICE * :*** Checking Ident
:strontium.libera.chat NOTICE * :*** Looking up your hostname...
:strontium.libera.chat NOTICE * :*** Couldn't look up your hostname
:strontium.libera.chat NOTICE * :*** No Ident response
NICK humpty
USER humpty humpty irc.libera.chat :Humpty Dumpty
:strontium.libera.chat 001 humpty :Welcome to the Libera.Chat Internet Relay Chat Network humpty
...

The ellipsis denotes lines omitted for the sake of brevity. The remainder of the session is quite similar to the first example in this post.

It is worth noting here that although the payload format of IRC protocol is quite simple, as one starts writing IRC clients, one would stumble upon several tiny details about the protocol that needs to be taken care of, e.g. authenticating to the network, responding to PING messages from the server to avoid ping timeouts, splitting messages into shorter messages so that the overall payload does not exceed the message length limit of 512 characters, etc. For a serious IRC client, relying on a suitable library that already solves these problems and implements the IRC specification accurately is of course going to be useful. But for a hobbyist who wants to understand the protocol and write some tools for fun, the textual nature of the IRC protocol and its simplicity offers a fertile ground for experimentation and creativity.

Join

In case you have never used IRC but this post has piqued your interest and you want to try it out, you probably don't want to be typing out IRC payloads by hand. You would want a good IRC client instead. Let me share some convenient ways to connect to the Libera Chat network. Say, you want to join the #python channel on Libera Chat network. Here are some ways to do it:

Join via web interface: web.libera.chat/#python.
Join using Irssi: On macOS, run brew install irssi to install it. On Debian, Ubuntu or a Debian-based Linux system, run sudo apt-get install irssi. Then enter irssi -c irc.libera.chat to connect to Libera Chat. Then within Irssi, type /join #python.

There are numerous other ways to join IRC networks. There are GUI desktop clients, web browser plugins, Emacs plugins, web-based services, bouncers, etc. that let users connect to IRC networks in various ways. On Libera Chat, there are various channels for open source projects (#emacs, #linux, etc.), communities around specific subjects (##math, #physics, etc.), programming languages (#c, #c++, #commonlisp, etc.). Type the /join command followed by a space and the channel name to join a channel and start posting and reading messages there. It is also possible to search for channels by channel names. For example, on Libera Chat, to search for all channels with 'python' in its name, enter the IRC command: /msg alis list python.

Although I have used Libera Chat in the examples above, there are plenty of other IRC networks too such as EFNet, DALNet, OFTC, etc. Libera Chat happens to be one of the very popular and active networks for open source projects and topic based communities. I use it everyday, so I chose it for the examples here. There are many tight-knit communities on Libera Chat. Some of my favourite ones are #commonlisp, #emacs, #python, etc. All of these have very nice and active communities with great attitudes towards beginners.

Algorithms Channel Migrates to Libera Chat

2021-05-19T00:00:00Z

Our ##algorithms that has been running on the Freenode IRC network for the last 14 years is now migrating to the Libera Chat IRC network. Our new channel name on Libera Chat is #algorithms.

History

The original ##algorithms channel on Freenode IRC began as an offshoot of the ##math channel there when we found that there was enough interest in the latter to form a channel dedicated to the subject of algorithms and data structures. I created the new channel for algorithms in 2007. I used to go by the nick spal and used to be active on both channels.

What began as a tiny hobby group around algorithms gradually grew to be be a thriving community with over 200 members. I don't participate in the channel much anymore but a highly talented group of moderators helps maintain the channel.

Migration

The original Freenode staff that used to run the Freenode network has stepped down after a controversial change in management of Freenode. The former Freenode staff has now launched a new IRC network named Libera Chat. Thousands of channels that used to exist on Freenode IRC earlier have been rapidly migrating to Libera Chat now. For more on the events that led to this mass migration, see this post: The Freenode Resignation FAQ.

The ##algorithms channel too has now moved from Freenode to Libera Chat. Our new channel name is #algorithms on Libera Chat. Our entire operator team for the channel is also moving to the new channel. The old channel on Freenode should now be considered defunct.

Old Channel Information

Here is the last known good state of the ##algorithms channel on Freenode before we declared the channel defunct.

/msg chanserv info ##algorithms
Information on ##algorithms:
Founder    : spal
Successor  : halberd
Registered : Oct 13 19:49:56 2007 (13y 31w 5d ago)
Mode lock  : +ntcC
Flags      : GUARD
*** End of Info ***

New Channel Information

Here is the current information of the new channel named #algorithms on Libera Chat.

/msg chanserv info #algorithms
Information on #algorithms:
Founder    : susam
Successor  : libera-placeholder-account
Registered : May 19 14:52:38 2021 +0000 (2h ago)
Mode lock  : +nt-lk
Flags      : GUARD PUBACL
*** End of Info ***

Join

If you are new to the world of IRC, here are some steps to join the Libera Chat network:

Install Irssi, an IRC chat client. On macOS, enter the following command if you have Homebrew:
```
brew install irssi
```
On Debian, Ubuntu or another Debian-based Linux system, enter the following command:
```
sudo apt-get install irssi
```
For other systems or environments, see irssi.org.
Enter the following command to connect to Libera Chat:
```
irssi -c irc.libera.chat
```
Now type these IRC commands into Irssi to join some channels:
```
/join #algorithms
/join #irssi
/join #libera
/join #linux
```
Enter this IRC command into Irssi to send me a message if you need any help:
```
/msg susam hello
```

You can also join the algorithms channel via Libera Chat's web interface at web.libera.chat. This can be useful for those who want to join the network quickly without installing a client. Further there is a Matrix bridge to the channel accessible via #algorithms:libera.chat. The Matrix bridge is quite convenient for someone unfamiliar with IRC. For example, you can close your browser or client and your chat session will still stay alive on the Matrix bridge. You can connect back the next day and catch up with the messages. Doing that with IRC requires setting up an IRC bouncers which may feel like considerable additional work.

Freenode Wipes Database

Update on 15 Jun 2021: All old communities on the Freenode IRC network are now gone. The new Freenode staff has wiped out their database thereby resetting the state of their network. We learnt about this when we received these global notices in our clients connected to the Freenode IRC network:

-root- [Global Notice 1/3] We are moving past legacy freenode to a new
       fork.  The new freenode is launched.  You will slowly be
       disconnected and when you reconnect, you will be on the new
       freenode.  We patiently await to welcome you in freedom's
       holdout - the freenode.

-root- [Global Notice 2/3] If you're looking to connect now, you can
       already /server chat.freenode.net 6697 (ssl) or 6667
       (plaintext).  It's a new genesis for a new era.  Thank you for
       using freenode, and Hello World, from the future.  freenode is
       IRC.  freenode is FOSS.  freenode is freedom.

-root- [Global Notice 3/3] When you connect, register your nickname
       and your channel and get started.  It's a new world.  We're so
       happy to welcome you and the millions of others.  We will be
       posting more information in the coming days on our website and
       twitter.  Otherwise, see you on the other side!

See this thread on Reddit for a discussion on this event: reddit.com/r/irc/comments/o01tmv.

What this really means is that decades old nicks and channels are completely wiped out! For example, my own 15 year old nick is now gone. Our algorithms channel on the Freenode network is also gone. All the nicks and other channels I was familiar with are also gone. I am not going to bother registering my nick and our channel there again! It is not worth it. We have all moved on to Libera Chat already and there is nothing left on Freenode to care about it anymore.

Read on website | #irc | #technology

Mathematics Storm

2011-05-12T00:00:00Z

From Freenode IRC #math channel this morning:

<oops> I have a confusion.  the calculation that was giving
       me 2 bits earlier is not giving me 2 bits now.  :(  please help.
<oops> 4 equally probable symbols: so 4 * (1/4) * log(1 / 1/4), right?
<antonfire> yeah math changes sometimes.
<antonfire> probably a math storm
<antonfire> wait a few minutes and try again
<_Ray_> try logging out and back in
<oops> so, so 1 * log(4) = 2
<oops> oh it is giving me 2 bits again
<mariano|syzygy> hmmm, actually he was not his advisor
<oops> thanks, nvm.
<sig^> try switching math off and on again
<thermoplyae> haha
<_Ray_> yeah, it was the router

Read on website | #mathematics | #irc | #humour