Howto Install CarvFS on your Ubuntu 8.10

I found a howto via forensikblog which wasn’t pretty good because it missed some details and installed CarvFS into your systems directories. You maybe want to have the carving files seperate from the rest of the system. So here comes a Howto Install CarvFS on your Ubuntu 8.10 machine:


cd /tmp/
sudo mkdir /opt/$USER/
sudo chown $USER:$USER /opt/$USER
mkdir /opt/$USER/carvfs
wget -O-  'http://downloads.sourceforge.net/ocfa/libcarvpath-0.2.0.tar.gz?use_mirror=mesh' | tar xvzf -
cd libcarvpath*
sudo apt-get install -y libsqlite3-dev libcurl4-openssl-dev
./configure --prefix /opt/$USER/carvfs && make && make install
cd /tmp/
wget -O-  'http://downloads.sourceforge.net/ocfa/carvfs-0.4.1.tar.gz?use_mirror=mesh' | tar xvzf -
cd carvfs*
sudo apt-get install -y libfuse-dev
export CFLAGS="-I/opt/$USER/carvfs/include/"
export LDFLAGS="-L/opt/$USER/carvfs/lib/"
./configure --prefix /opt/$USER/carvfs && make && make install

Happy Hacking

CeBIT 2009

I have been at the CeBIT to represent GNOME. Actually, Herzi got sponsered by his generous employer, Lanedo, to make the GNOME booth happen. And he probably got bored that he called me up to do this together 🙂

We were in Hall 6, booth F60, sitting next to Drupal and some LDAP Webthing. Also, the KDE guys were next to us 🙂

They had awesome posters hanging on the walls, nice T-Shirts hanging around and banners showing off. They even came with name cards pinned on their chests and probably even with working hardware. The Drupal guys had a Roll-Up display and a foldable flyer holder with many information materials.

I envy those guys, because we haven’t had any of this stuff, besides a small computer and a monitor 🙁 There probably is something in GNOME Event Box, but unfortunately Herzi didn’t bring it, probably because it’s way too big and too heavy. Also, a roll-up display wouldn’t fit into that Box. Posters and banners would be nice, too. We even had to install an Ubuntu on the fair (instead of having it prepared beforehand). Then, the webcam didn’t want to work with cheese, so we couldn’t use that as an eye-catcher. Anyway, Sudoku and gnome-about were pretty good 😉 I believe, LinuxTag is going to be better, though. Because we have GNOMErs right there and you can transport things fast and easily, so it’s no big deal to replace a camera or a second PC.

Anyway, most of the time, we told the people, what GNOME is and automatically came to what a “desktop” is, what this “Open Source” thing is and what “Unix like systems” are. Some people actually had Linux experience and have a second (linux) partition, a VMWare or a server running linux.

We were also answering questions related to GNOME 😉 Users were asking what’s new in GNOME, how they use the accessibility stuff or the like. We used the chance of talking directly to users and asked what they like and dislike about GNOME. It turns out, that most of the time, the people are satisfied with their GNOME desktop, because it “just works” and it’s not in their way to achieve things. Also, they thought that the GNOME desktop is more light-weight than, e.g. the KDE desktop. Some people disliked that it looks a bit old-fashioned and that they can’t “play around” as much with their desktop as they are used to from, say, using windows. I told them, that it’s a design philosophy, to not have a huge (obvious) configuration space but to try to make it as easy as possible to do regular stuff. Of course, there is GConf where the about-to-be hackers can turn the nipples (and see the result instantly). I also tried to convert a few users to hackers: I even gave one guy “homework” to do… We’ll see how it turns out *g*

One guy asked me why he should choose GNOME over KDE. I avoided the whole discussion and gave no reason back. He should use what he likes and what fits his needs. Of course, I explained the philosophies behind GNOME and tried to make GNOMEy points.

Another one asked, whether there’s a “german GNOME community” and I sadly had to say “no”. But I hope, we Krauts can meet at LinuxTag and do that name-to-faces thing in a cosy restaurant. Maybe it’d be a good idea to pick one which has *no* WiFi or GSM/UMTS coverage, just to have no excuse to not talk to each other 😉

We pointed many people to our Wiki on live.gnome.org, especially the Roadmap or gnome-love. Let’s hope, they want to give some love to GNOME and fix some bugs 🙂

Of course, there were good parties at the end of the day, as well 🙂

Gadgets from Hongkong

I ordered some gagdets from focalprice.com, after read about that shop. I know dealextreme.com for quite some time now, but I’ve never dared to order something. And I’ve never heard about focalprice, which seems to be more or less the same shop anyway.

honkonggadgets

I’d say they delivered very fast. It just took 2.5 weeks to ship that stuff from Hongkong… Another interesting fact is, that German post delivered that as registered mail, which is positive, though.

Translation FAIL
Translation FAIL

Well then, I’m off playing with my new gadgets 😉

PyFon – Being a Fonero

The problems I described last time, are gone now 🙂 The paramiko mailinglist is, besides the pretty good documentation, a very good information ressource.

So I built a Fon client in Python which allows you to login to the Fon server and make your Fonera officially online.

So in order to get your copy of PyFON, do a

hg clone http://hg.cryptobitch.de/pyfon

To use it, simply give the MAC address of your Foneras wireless interface as an argument and run it or do it in a more sophisticated way:

muelli@xbox:~/hg/pyfon$ python ./src/pyfonclient.py --loglevel info --firmware 0.7.2 --revision 3 --mode cron --ethernetmac 00:18:84:fo:ob:ar 00:18:84:fo:ob:ar
INFO:root:Connecting to host: download.fon.com:1937 as user: openwrt
INFO:paramiko.transport:Connected (version 2.0, client OpenSSH_4.3p2)
INFO:paramiko.transport:Authentication (publickey) successful!
INFO:root:Connect finished
INFO:paramiko.transport:Secsh channel 1 opened.
INFO:root:Found _auth_string: mode='cron' wlmac='00:18:84:ff:ee:dd' mac='00:18:84:fo:ob:ar' fonrev='3' firmware='0.7.2' chillver='1.0-1' thclver='1.0' device='fonera'

INFO:root:Finally closing everything
muelli@xbox:~/hg/pyfon$

If you increase the loglevel to, say, debug, then you’ll get the script which Fon send you and supposes you to execute. If you change your password via the Fon webinterface, you’ll see your new password in that script.

So if you want to disturb the Fon network, you can iterate over all Fon MACs and receive the possible made configuration changes. By that, you’ll get the new passwords as well, of course…

Another funny thing is that the Fon server sends you their banner, if you explicitely request a shell:

In [1]: import pyfonclient
In [2]: c  = pyfonclient.Client()
In [3]: c.connect()
In [4]: channel = c.client.invoke_shell()
In [5]: channel.recv_ready()
Out[5]: True
In [6]: buf=""
In [7]: while channel.recv_ready(): buf += channel.recv(1)
   ...:
In [8]: print buf
Linux fonesfat02 2.6.18-6-amd64 #1 SMP Sun Feb 10 17:50:19 UTC 2008 x86_64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
In [9]:

But you can’t execute any command…

Patches are, as always, welcome 🙂

Free FON

You might know that FON thing, which basically provides you with WiFi on many places. They give you an access point which they suppose you to run and provide that WiFi to others. Then you are eligible to use other peoples WiFi.

The given access point connects itself with a script to the main server and tells it, that it’s online. The server then grants you access to other WiFis.

If you flash the access point, which is called “fonera”, with e.g. OpenWRT then you’ll lose that script. This in pretty bad because you *do* provide free WiFi to the people (unless you don’t run an open WiFi) but lose the right to use others.

There are sites out there which describe, howto do the “heartbeat” yourself, but they have major drawbacks:

  • They are written in Bash
  • The key used is in dropbear format, and not OpenSSH

Also note, that you can receive the files from the Fon development site and steal that heartbeat thing from there.

Thanks to this site I found a way to convert the dropbear key to the OpenSSH format (/usr/lib/dropbear/dropbearconvert dropbear openssh fonkey fonkey.ssh), but that bash thing is still ugly. Also, to use OpenSSH, you have to fiddle with permissions of the keyfile, etc.

So in order to run that heartbeat thing properly on, say, your PC, you don’t want to depend on dropbear or “nvram” to get the MAC address of your wireless interface. You might want to run the following script, of course you have to adapt the variables first. I try to get rid of Bash, but I still have a few problems with Pythons SSH package: I can’t send something to “stdin”, like “echo 'foo' | ssh bar” does.

#!/bin/sh
#
# version 1.1.0 

THINCLIENTPATH="/tmp" # path of this file
ROOTHOME="/tmp/root" # root's home dir
SSHPATH="/usr/bin/ssh" # path to ssh
KEY="/tmp/fonkey.ssh.1" # private key for fetching the info from the FON server
THINCLIENTOUT="/tmp/.thinclient.sh" # output file

THINCLIENTOUTDEFAULT="33" # default size of the output file

THCLVER="1.0"
CHILLVER="1.0-1"
FONREV="2" # /etc/fon_revision
FIRMWARE="0.7.2" # taken from /etc/banner (without Beta)
DEVICE="fonera"

USER="openwrt"
SERVER="download.fon.com"
PORT="1937"
FONSIG="$SERVER ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEA0zJFtj5NtrVsj8+qG0dtPE8WpHHDpTXp5+d3vvtSS7Hx7vYHyrfN/8PBVrrYOgl4dySY65sGtq34EU04VN4a7xQHSKJBunDUSQ/2Xz+eyo53LCVeFy1zNRCmB6jrFlJQvl5yviLvXmMtOGxG8Z1dfu4qavfGtBxwtwxKPKuiyhs="
cat > $KEY <> $ROOTHOME/.ssh/known_hosts
}

exec_cron_mode () {
	check_env
	sleep "$((0x$(head /dev/urandom |hexdump |awk '$2 > 0 {print $2}'|head -n1) % 10))"
	echo "mode='cron' wlmac='$MAC' mac='$ETMAC' fonrev='$FONREV' firmware='$FIRMWARE'" | $SSHPATH -T ${PORT:+ -p $PORT}${KEY:+ -i $KEY} "${USER}@${SERVER}" > $THINCLIENTOUT
	echo "sent: mode='cron' wlmac='$MAC' mac='$ETMAC' fonrev='$FONREV' firmware='$FIRMWARE'"
	exec_check_thinclient
}

exec_start_mode () {
	sleep 10 # make sure WAN is up and crond is running
	check_env
	[ -f "/tmp/crontab" ] || touch /tmp/crontab
	[ `grep -c thinclient /tmp/crontab` = "0" ] && echo "24,54 * 	*	**	root $THINCLIENTPATH/thinclient cron > /dev/null 2>&1 &" >> /tmp/crontab
	echo "mode='start' wlmac='$MAC' mac='$ETMAC' fonrev='$FONREV' firmware='$FIRMWARE' chillver='$CHILLVER' thclver='$THCLVER' device='$DEVICE'" | $SSHPATH -T ${PORT:+ -p $PORT}${KEY:+ -i $KEY} "${USER}@${SERVER}" > $THINCLIENTOUT
	echo "sent: mode='start' wlmac='$MAC' mac='$ETMAC' fonrev='$FONREV' firmware='$FIRMWARE' chillver='$CHILLVER' thclver='$THCLVER' device='$DEVICE'"
	exec_check_thinclient
}

exec_check_thinclient () {
	if [ -f $THINCLIENTOUT ]
	then
		THINSIZE="$(wc -c < $THINCLIENTOUT)"
		if [ $THINSIZE = "0" ]
		then
			echo "Something is wrong, $THINCLIENTOUT is empty"
		elif [ $THINSIZE != "33" ]
		then
			echo "Something is different in $THINCLIENTOUT:"
			cat $THINCLIENTOUT
		else
			echo "$THINCLIENTOUT is the default one, deleted"
			rm $THINCLIENTOUT
		fi
	else
		echo "Something is wrong, $THINCLIENTOUT does not exist!"
	fi
}

case "$1" in
	cron)
		exec_cron_mode
		;;
	start)
		exec_start_mode
		;;
	check)
		exec_check_thinclient
		;;
	*)
		echo "Usage: `basename $0` {cron|start|check}"
		exit
esac

DAAD Recall

Journey

I applied for a stipend from the DAAD, the “German Academic Exchange Service”, in November. They must have liked my application because they invited my to the “next round” in the former capital Bonn.

Bonn Hauptbahnhof
Bonn Hauptbahnhof

I got some LIDL train tickets on eBay for 70 Euros (thanks Mezzo), which were 55 as they were sold by LIDL. Flying wasn’t an option due to the airports, both Hamburg and Koeln-Bonn, being located outside the cities and would have brought travel overhead which takes time as well. I enjoyed my non-stop train trip and arrived in Bonn after almost 5 hours.

Altes Rathaus in Bonn
Altes Rathaus in Bonn

Hostel

Akademisches Kunstmuseum
Akademisches Kunstmuseum

After a short stroll through the city, I went to my Hostel: Max Hostel in the old town. They seem to be rather new since they were obviously surprised that I arrived. The guy at the reception left a clueless but happy impression. That Hostel offers a kitchen with Pasta and coffee for free! Especially the latter is pretty important 😉 Though, I was not amused by the fact, that the showers were on the outer floor, where everybody is on his street shoes.
But the beds were pretty good and I slept nearly 11 hours.
Maybe that’s due to my long walking trip through Bonn. I got lost several times on my way to the museums but that wasn’t too bad as I could see Bonns living district with beautiful old houses.

Altbau in Bonn
Altbau in Bonn

If you are ever going to Bonn, don’t miss the “Haus der Geschichte”! An excellent Museum covering different aspects of German history.

Boennsch Koelsch
Boennsch Koelsch

Before I went to bed, I had a few big Schnitzel together with Beer^W “Koelsch”. Last time I had a Koelsch it reminded me of water rather than beer but this brand, “Boennsch” was quite good.

Boennsch Pub
Boennsch Pub
Kommunisten-Nazi
Kommunisten-Nazi

Questions

Uni Club
Uni Club

So I went to the Uni Club Bonn to have a talk to the selection committee. Other students were already waiting in front of the talking room. The amount of administrative overhead to select the ones who will receive the stiped is impressing. They do that selection talk thing the whole day, from 10:00 to 18:00, in 4 rooms in parallel.
But let’s get to the guts of that talking. I tried to prepare for that discussion with googling facts about it. I didn’t find much so I’m going to list the questions and the atmosphere. If you have questions left, feel free to drop me a line.

MozarthausI was called to come into the room and I was pretty nervous. I haven’t been so nervous even right before exams. I was invited to have a seat in front of a table with ready-to-drink water. The committee sat in front of a separate table and they counted 7 people. The committee was introduced to my by one of them. She introduced each member: Four of them were professors from different places in Germany, one student who got the stipend a year ago and two DAAD executives. And then it already begun. The professor asked four or five questions at once:

Main university building
Main university building
  • Why I was studying computer science
  • Why I am interested in computer security
  • Why I want to go to Dublin
  • Why the DAAD should give the stipend to me and not to anybody else

I began saying that I hope to not forget any of these questions. The prof immediately said that he asked so many question at once so that I can talk for a long time…
So I told my story: I am interested in computer science since I was a child, I got in touch with security very early, blablabla. Of course I forgot a few points, e.g. why I wanted to go to Dublin and why *I* should be sponsored.
But my talking drifted into a nice dialogue. I told them about the situation on my home university, especially that our security staff has gone and they asked a couple of questions like whether the professorship is going to be replace or whether I was able to do a diploma thesis at my home university.

Rheinland dreht zu Fasching durch
Rheinland dreht zu Fasching durch

Other questions include

  • Where do I see myself in 5 years
  • Where do I see the best university for computer security
  • What kind of experience I had in computer science and what my (university) projects were about
  • What would I have studied if I wouldn’t have taken computer science
  • Which news of the last week moved me

While the whole talking was in German, the student suddenly asked in English me why I needed so much time for my studies. We discussed like one minute or two after we switched to German again.

While I was pretty happy coming out of that room after 15 minutes, I think I didn’t perform very well. The more I think about it, the less I like my answers.I didn’t set any particular weights and gave unnecessary answers which are not of any interest.

The atmosphere, however, was okay. Everybody seemed interested and had a pile of paper in front. Nobody picked on a particular shortcoming and were high level in general.

Weirde Abkuerzung
Weirde Abkuerzung

So I missed to make a few points and while I think about my answers afterwards, I think I could have given smarter ones. But we’ll know more in about three weeks, because the DAAD executive said, that they’ll send a mail then.

I was about to go to the Arithmeum and the Haus der Geschichte but unfortunately they were closed on Mondays 🙁 So I went to have lunch and a beer before I went to the railway station to get home.

Das Bier danach
Das Bier danach
Creative Commons Attribution-ShareAlike 3.0 Unported
This work by Muelli is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported.