Archive

Archive for March, 2009

Ubuntu, lirc and the Antec Black Fusion (15c2:0038)

March 30th, 2009

After getting my Antec Black Fusion, I just couldn’t get it to work in Ubuntu with lirc 0.8.4a, so I went ahead and created some simple packages for lirc 0.8.5pre1 which do appear to work with this case / device.

Notice: Please note in preparing these lirc 0.8.5pre1 packages I’ve dropped a fair few of the Ubuntu specific enhancements to lirc since this is intended as a fix solely for adding support for this device. Debdiffs welcome. ;-)

Firstly add my repository key to apt so that the packages authenticate:

$ wget -O - http://packages.kennynet.co.uk/repository.key | sudo apt-key
add -

(note: trailing dash)

Next grab the sources.list entries for my repository so you can download the 0.8.5pre1 packages:

$ sudo wget -O /etc/apt/sources.list.d/kennynet-testing.list

http://packages.kennynet.co.uk/intrepid-testing.list

Now we’re ready to install the packages as follows:

$ sudo apt-get update
$ sudo apt-get install lirc lirc-modules-source

With these packages installed, you only need the following line in /etc/lircd.conf:-

include "/usr/share/lirc/remotes/imon/lircd.conf.imon-antec-veris"

I’ve also made a custom (somewhat hacky) startup script which’ll launch the required two lircd daemons for the two lirc devices created under /dev.

You can download the script here, just put it in /etc/init.d/: lirc-imon

Now make it executable and set it to run on startup:

$ sudo chmod +x /etc/init.d/lirc-imon
$ sudo update-rc.d -f lirc remove
$ sudo update-rc.d lirc-imon defaults 51

This’ll disable the default lirc init.d script and enable the lirc-imon one that I’ve created.

From then on I’d make sure it’s loaded the new modules / started lirc as follows then test it out using irw:-

$ sudo /etc/init.d/lirc stop
$ sudo modprobe -r lirc_dev lirc_imon
$ sudo /etc/init.d/lirc-imon start
$ irw

Press some buttons, they should now show up.

All works for me, let me know how it goes… there are numerous debug steps at each stage if it doesn’t work but I’ve left these out to try and keep the e-mail relatively short. We can go through those if you still experience problems. Please leave comments if you have any questions.

I’ll package the very latest imonlcd patch for lcdproc and upload that to my testing repositories soon and make another quick post.

Linux , , ,

Iomega StorCenter Pro 200rl root access

March 13th, 2009

So we got one of these NAS boxes at work and like all self respecting sysadmins we wanted root access on the box ideally with SSH, unfortunately the NAS server doesn’t support this. However it is trivial to obtain root access by using an Ubuntu live CD as follows.

Firstly boot off the live CD and once you have your live CD desktop open up a terminal window, we now need access to the system drive on the NAS box which we can acquire as follows:-

$ sudo apt-get install mdadm
$ sudo mdadm --assemble --scan
$ sudo mount /dev/md3 /mnt

Next we need to make sure we’re working on the NAS system drive for all our commands so let’s chroot into it:-

$ sudo chroot /mnt

To reset the root password we need to run:-

 # passwd

To enable SSH (which is already installed) on startup we need to run:-

# update-rc.d ssh defaults 16

Finally we cleanup and reboot the NAS server:-

# exit
$ sudo umount /mnt
$ sudo reboot

Don’t forget to remove/eject the CD when the Ubuntu live CD prompts you to.

Now once the NAS reboots into its native OS (which happens to be Debian) you’ll find you’ll be able to login to the box as root with all the power that comes with it.

Tech ,

PHP app Licensing Faux-pas

March 10th, 2009

One of the php web applications we use in the office requires a license to work, it locks its license to the hostname and ip address of the server on which it’s run.  When the license key is first entered it phones home to set the hostname and ip address on the licensing server and then stores a valid hash of the license.

We recently restructured our network and changed the ip address thus causing the app to complain the license was invalid, deleting the licensing file caused it to talk with the licensing server again but it was no use the licensing server still held the old ip address which was no longer correct. At this point I sent an e-mail off to their customer support team to get the information changed.

However, I couldn’t resist  taking a quick peek under the hood. To their credit the app is largely open source and readable except for the code that manages the license which is encrypted.  I removed the license file, fired up wireshark which logged the following conversation to their license server (anonymised to protect the guilty):-

GET /XXXXXX.php?license_key=Base64String&host_name=?Base64String&
host_ip=Base64String

Which generated the following reply:-

license-key|host-name|old-ip-address

On the face of it this seems quite easy to attack given it sends the current hostname/ip to the licensing server it’d be a trivial PHP script to send back what we assume the app would want to see:-

$key = base64_decode(urldecode($_GET['license_key']));
$host = base64_decode(urldecode($_GET['host_name']));
$ip = base64_decode(urldecode($_GET['host_ip']));

echo "$key|$host|$ip";

All that remains to do is set the script up on our server, and add an entry into our /etc/hosts file so that the licensing server domain name now points at our server. Once done after removing the license file I hit refresh and surprise surprise the app accepted the license response and things continued as normal.

This is particularly weak scheme since it doesn’t even run over SSL so capturing with wireshark is trivial. The other fundamental problem is that the class which converses with the licensing server is not encrypted so that would represent another point of attack which wouldn’t require setting up a fake licensing server – just hijack the response methods.

To their credit the license key itself is validated using a hash to determine what level of features you have access to but once you’ve bought one key you are then able to apply the methods above to copy the key to as many different locations as you wish.

Any comments identifying the application in question will be removed or censored, this is not an aid to bypassing licensing requirements more a discussion of the security implications of how this particular method was implemented.

Coding , ,