PACKT publishing, September 2011

BackTrack 5 Wireless Penetration Testing Beginner’s Guide!

I received a copy of this book one month ago. Due to other projects, I couldn't start reading immediately.

Vivek Ramachandran wrote this book.  Vivek is a security researcher originally from India who seems to be good known on all security conferences.

The book is not too big (about 200 pages) and you find many screenshots of terminal outputs. And you will need these screenshots because they explain many things even better than a long description.

Why BackTrack Linux? The author writes his motiviation in the preface. BackTrack is a distribution with lots of security utils already on board. I tried it with Debian stable because this was already installedon my laptop. This works too, but you have to download and build several tools by your own.

I read the book like a thriller! Every chapter has several sections where you get step by step deeper into the wireless analytics. I knew most basics before. But didn't know how easy it is to crack a WEP-encrypted network. And I learned that hidden ESSIDs help absolutely nothing!

It's good to know the handling of wireless on the linux console and to understand basics of the protocoll. But if you don't: you learn it quite fast with the book howto bring up your wireless interface with iwconfig, wpa_supplicant and co.

But It's not only reading. It's practical beginner's guide. It makes fun to follow the steps described. And I was happy to fail to crack my WPA2-protected network with the dictionary attack.

There is a sample chapter online about the advanced WLAN attacks. There you can enjoy the screenshots even in color :-)

In the last chapters you start working on RADIUS networks. This complex topic is made a little easier with BackTrack Linux because there is already a preconfigured freeradios-server installed.

Last week, I read again some forum posts about the Compulab Trim-Slice and.... Yes, I ordered one Trim-Slice Pro directly from Compulab in Israel! It costs $370 including shipping to Germany.

It was quite fast with UPS Saver in Dresden. Compulab shipped it on Sunday, 31th July and it arrived today on Tuesday, 2th August. Yesterday, UPS from Cologne called me to get my customs-tariff-number. I have never heard about this but I applied for one and this was enough for UPS and the customs. I only had to pay the import VAT (19%) but this will be refunded later.

Puh, it was quite easy to start the Trim-Slice. I just connected my monitor with an DVI-HDMI-cable, plugged the power and after approximately 2 minutes the Ubuntu desktop was seen. There is no boot-logo, splash-screen or text console to follow. I don't know yet, howto edit e.g. the u-boot parameters. I will see later.

The system works, even wireless seemed to work at the first glance. But later I noticed that it is quite unstable with my WPA2 protected network. I'm not sure why, but I started to compile the trimslice-kernel and to replace the included rt2800usb driver with the rt2870sta from RaLink. With no success until now :-(

At the moment, the Trim-Slice seems to be slower than my Fit-PC2 and it's getting hot because the power management is not working yet. Unfortunately, I cannot measure the power consumption at the moment. This and many other details will follow in this blog.

So stay tuned!

Update:

Accessing the u-boot is so easy. That's why the Trim-Slice has an ordinary serial port! Connected with a null-modem-cable and an USB-serial-converter, you can access the console with minicom. There you follow the boot process and you login automatically as root user. Great! My own, native compiled kernel is working now.

I just realized that kernel 3.0.0 is available since friday. So I just compiled it with my config from 2.6.39 and... trara: it's working! Here you can find my new config-3.0.0 for the fit-pc2.

Compared to the last kernel upgrade, this one was quite easy. The psb_gfx driver comes still from the psb-dkms package.

What's new in kernel 3.0.0? First: the version numbering. After 2.6.39 follows now 3.0.0. Ok, if Linus like so, why not. We are working to long with 2.6. But I hope, the linux kernel is not following now the version numbering inflation like chrome and firefox...

There is a quite good site where the changes are explaned: http://kernelnewbies.org/LinuxChanges

Since my update to Ubuntu 11.04 I missed a very, very useful and important feature for people like me, working most of the time on the console.

I don't care which window-manager-system-style I'm using. GNOME, KDE, LXDE or whatever as long as the terminal is starting fast.

In Ubuntu 11.04 is a bug with the bash_completion. This helps you completing the filenames with the TAB-key. Especially with filenames and directories with spaces or German "Umlaute".

Right now, I spent half an hour to google for a solution and it's so simple. There is only an error in /etc/bash_completion (line 1587):

# makeinfo and texi2dvi are defined elsewhere. 
for i in a2ps awk bash bc bison cat colordiff cp csplit \     
curl cut date df diff dir du enscript env expand fmt fold gperf gprof \     
grep grub head indent irb ld ldd less ln ls m4 md5sum mkdir mkfifo mknod \     
mv netstat nl nm objcopy objdump od paste patch pr ptx readelf rm rmdir \      
sed seq sha{,1,224,256,384,512}sum shar sort split strip tac tail tee \        
texindex touch tr uname unexpand uniq units vdir wc wget who; do     
have $i && complete -F _longopt -o filenames $i 
done 

This bug has been discussed on the bugtracker at launchpad:

https://bugs.launchpad.net/ubuntu/+source/bash-completion/+bug/769866

Recently, I spent a couple of hours to update and upgrade my fit-pc2.

I started with the kernel which was running 2.6.37.1 with the psb driver for the Intel GMA500 (Poulsbo) graphics engine. Unfortunately this driver isn't maintained anymore and does not compile with 2.6.38 or even 2.6.39 kernels.

But in the meantime, a new driver entered the staging tree of the kernel and is already part of 2.6.39. This driver-directory is called gma500 but the module is named psb_gfx and the driver is named psbfb. This driver supports Kernel Mode Setting (KMS) and uses the fbdev driver from xorg.

It took me some hours to get this running. Of course because I even compile the kernel on the fit-pc2 which is not that fast. But the biggest problem was to find a working kernel config and the setting for the right display resolution. In my case the monitor is connected to DVI (on the HDMI  plug) and has a native resolution of 1440x900.

Here is my kernel config for 2.6.39.2 and I had to change the grub default settings in /etc/default/grub for my monitor:

GRUB_CMDLINE_LINUX="acpi_osi=Linux acpi_backlight=vendor acpi_skip_timer \
     nomodeset video=DVI-D-1:1440x900 pci=nocrs mem=896mb"

Please note: the current driver doesn't support reading your monitor EDID data by itsself. It will start with 1024x768 by default. To get information about the connector (in my case DVI-D-1), I added the parameter "drm.debug=7" to the kernel command line.

I don't know why, but I still need a xorg.conf file. Without it, the USB keyboard and mouse won't work.

After the kernel, I upgraded Ubuntu from 10.10 to 11.04 without any problems.