GHM — GNU Hackers' Meetings
GNU Hackers' Meeting 2014 — Munich, Germany
The eighth GNU Hackers' Meeting took place
August 15–17 2014 in Munich, Germany.
See our Videos
The GNU Hackers' Meeting is a friendly, semi-formal forum to discuss
technical, social and organizational issues concerning free
software and GNU.
It is open to all people who have an interest in the GNU Project and its goals.
This year's GHM is
hosted by TUM, the Technische Universität München.
See the practical information below for how to get there.
Note: The views presented at GHM 2014 are the opinions of the respective speakers.
They do not necessarily reflect the policy of the GNU Project or
the Free Software Foundation.
Programme of events for GHM 2014
|Friday 15 August|
|10:00 – 10:30||Welcome and Introduction|
|10:30 – 11:30||
Knock: Practical and Secure Stealthy Servers
Today, port scanners can scan all IPv4 addresses in less
than one hour. Port knocking is a method for making TCP
servers less visible on the Internet. The basic idea is to
make a TCP server not respond (positively) to a TCP SYN
request unless a particular “knock” packet has been sent
first. This can be helpful for security, as an attacker
that cannot establish a TCP connection also cannot really
attack the TCP server.
There are a bunch of existing user-space tools, such as
Knock Knock and knockd. Most of these implementations send
some other traffic (such as a UDP packet) to the target
host to have it (briefly) open the server port.
We present Knock, an
implementation of port knocking in the Linux kernel which
offers a simple, robust way for user applications to
achieve both — authentication of the communicating parties
and (given a sane protocol) integrity protection of the
TCP transmission. “Knockified” traffic does not differ in
any way from normal TCP traffic and Knock works well for
clients behind NATs, as
current research shows.
Knock ships as a set of patches to the Linux kernel
together with a shared library which enables users to
nockify their user-space applications without having to
write any line of code.
|11:30 – 12:30|
Special Guest: FSFE
|12:30 – 13:30||Lunch|
|13:30 – 14:00||Keysigning|
|14:00 – 15:00||
We're building the GNU System!
GNU hackers have been building it for three decades, and now GNU Guix
is bundling it up together! Two years ago in Düsseldorf Guix was
introduced as a possible way to build the GNU system distribution. So
much hacking since then! We'll present that and showcase the nifty
system configuration and installation tools that have landed recently.
We'll talk about the road to version 1.0 of the GNU system and beyond.
This talk is also a call to GNU hackers to unite and shape up the
system. Let's GNU things together!
|15:00 – 15:30||Afternoon Break|
|15:30 – 16:00||
“Fork me on BinHub” is getting hype these days. But it's even more
interesting to merge, or unfork, similar projects projects, and
making them stay that way. In this session I'd like to present
some of the choices I made to merge my projects with others, to
prevent gratuitous forks, what challenges we face to get further,
and get feedback and experience from the audience.
|16:00 – 16:30|
Taler: Taxable Anonymous Libre Electronic Reserves
This talk will introduce Taler, a Chaum-style digital currency using
blind signatures that enables anonymous payments while ensuring that
entities that receive payments are auditable and thus taxable.
|Saturday 16 August|
|10:00 – 10:30|
Who maintains the maintainers? An overview of the GNU Administration
our software forms the visible face of GNU, behind the scenes
many people are working to ensure that the organization can
consistently and efficiently support the development of the GNU
system. I will give an overview of the various teams that work
to maintain GNU, presenting the jobs they do, connecting faces
to familiar names, and showing where there is room for your
|10:30 – 11:00|
In recent years instant messaging (IM) gained a lot in popularity. Virtually
everyone uses one or more IM solutions (e.g. WhatsApp, Skype, iMessage, Facebook
Messenger etc.) for private conversations. Especially the ease of use that comes
with this kind of online communication combined with the high availability
through the popularity of smartphones makes IM attractive for a broad audience.
Also companies have discovered IM as a suitable solution for online business
meetings, particularly because it causes no additional costs.
At its heart IM emulates the behavior of a private conversation held in person.
Naturally people expect their face to face conversations to have several
properties. For example for any party that did not participate in the
conversation the (hopefully) honest word of the participants is the only proof
of what was said during the conversation (given that no one recorded it). To be
a suitable alternative to face to face conversations IM should also satisfy
these properties. It is also not astonishing that people without a strong
knowledge in computer science and/or cryptography already expect their private
online conversation to be held under these constraints.
However, the dominant IM solutions do not satisfy all of these properties.
Security concerns fuelled by the revelation of surveillance activities of
government institutions last year have lead to a more wide spread awareness for
the need to secure communication over the internet. Therefore we are
implementing libgotr which tries to solve this problems.
|11:00 – 12:00|
Introducing GNU Posh
|12:00 – 12:30|
Self Study with Glean
'Glean' facilitates self-study through tutorials, and 'problems'. The
problems are built using different questions types (multiple-choice,
open-ended), with arbitrary evaluation rules (e.g. answers could be
programmatically evaluated, or based on simple comparison / parsing
rules), and rich media support materials (mainly in the form of URIs,
which the client renders as it sees fit).
|12:30 – 13:30||Lunch|
|13:30 – 14:00|
Gforth is the GNU project implementation of the Forth programming
language. This talk will give an introduction in what Forth is, what
the goals of the Gforth project are, and how the underlying vmgen
technology can help to implement other programming languages. An
outlook of future development will be given.
|14:00 – 15:00|
GNU Name System
This talk introduces the design and implementation of the GNU Name
System (GNS), a fully decentralized and censorship-resistant name
system. GNS provides a privacy-enhancing alternative to DNS which
preserves the desirable property of memorable names. Due to its design,
it can also double as a partial replacement of public key
infrastructures, such as X.509. The design of GNS incorporates the
capability to integrate and coexist with DNS. GNS is based on the
principle of a petname system and builds on ideas from the Simple
Distributed Security Infrastructure (SDSI), addressing a central issue
with the decentralized mapping of secure identifiers to memorable
names: namely the impossibility of providing a global, secure and
memorable mapping without a trusted authority. GNS uses the
transitivity in the SDSI design to replace the trusted root with
secure delegation of authority, thus making petnames useful to other
users while operating under a very strong adversary model.
|15:00 – 15:30||Afternoon Break|
|15:30 – 16:00|
Ode to a Childhood Dream
I will present a GNU epsilon cross-compiler to the Commodore 64,
finally bringing free software to my first computer, twenty-five years
later. The clean extensible design of GNU epsilon allows easy
portability and a high-level programming style — even on a machine
with an 8-bit 1MHz processor and 64KB of RAM. A sprite demo will be
|16:00 – 16:30|
Call for action: A data visualisation layer
Data visualisation is an important aspect of analysis. Whilst
there are several free data visualisation libraries available, none
have all the features one would desire to include in a comprehensive
data analysis tool.
In this talk, I will review the existing solutions, and provide
suggestions for providing an extensive library which could fill this
gap in the GNU system.
|Sunday 17 August|
|10:30 – ||Closed session for GNU maintainers.||GNU Maintainers only.|
Attendance is free of charge, but prior registration is essential.
You can register using the web form or by email.
To register by email, send the following details to
- Your name.
- Any free software related projects with which you are associated.
- Whether or not you are willing for your name to appear on the published list of attendees.
- If you wish to propose a talk or presentation, see above.
You are welcome to make a small (or large) donation
if you want to support future GNU Hackers' Meetings.
The FSF has kindly set up a small
fund to help finance documented travel expenses for GNU
maintainers and contributors, past and present.
Dispersements are approved based upon the applicants' ability to
cover expenses from other sources, the extent to which she has contributed
to GNU and the total demand upon the fund.
If you qualify
and you need financial assistance to attend, please mention this
fact in your registration e-mail, along with all the relevant
details including the minimum amount that would permit you to attend
the event, no later than June 13 2014.
The meeting takes place in the Leibnitz-Rechenzentrum at the Garching Forschungszentrum Campus
of the Technische Universität München.
There are numerous hotels in the vicinity.
Munich is well served by air, rail and road, and getting to the venue from the airport
and railway station is possible by the local public transport.
See this link.
If you are traveling by car, save money and the planet by bringing a passanger.
Use the public mailing list to find a travel partner.
T-Shirts will be available for purchase. Stocks are limited. Price: €13.
Preference will be given to those who pre-ordered.
We wish to thank TUM
who graciously offered to host the meeting.