Automatically Start X with GDM in BackTrack 5

I’ve heard about BT5 a while ago, but since it’s also a Debian-based distro and I’ve been using Debian-based Linux distributions for like one-third of my life, I was reluctant. Until a couple of weeks ago, after a friend told me that it comes out-of-the-box with tons of InfoSec tools I’ve decided to give it a try just to see what it really can do. So I downloaded and install it in VirtualBox to give it a test-run.

My first impression was it’s like Arch Linux. By default, you’d be booted up on a Tty and you have to manually login as ‘root,’ with ‘toor’ as the default root password Then you have to run ‘startx’ so you can have a graphical interface – the BT5 way. It’s pretty simple actually, but I don’t think it’s a very good idea for any smart Linux user to run it’s entire system as root all the time. You might destroy your important system files before you know it.

So in this tutorial let me share to you how I created a sudoer (regular user) account in a fresh installed BT5. And then we will try and install Gnome Desktop Manager (GDM) because Gnome is the default desktop environment pre-installed in BT5.

OK, first we need to make a sudoer. It’s actually very simple. Simply fire up your Terminal and then run the following command (assuming that you don’t have a user account yet, so we’re doing the entire process as root):

For this example, we are going to use ‘homer125‘ as our test username.

# useradd -m -g users -G admin,video,disk,games,cdrom -s /bin/bash homer125

Then we need to add a password to your username:

# passwd homer125

Enter new UNIX password:

Retype new UNIX password:

passwd: password updated successfully

After we have created a sudoer, we’re going to install GDM, so we can boot up and login directly using the username (homer125) we’ve just created. To install GDM simply run this command in your Terminal:

# apt-get install gdm

Now we need to test GDM and see if it’s working the way it should. To run GDM simply run this command:

# gdm

If GDM is working the way it should, you should see the good old Gnome login screen. Let me remind you , the default login screen is quite ugly so you gonna have to be patient about it, you can change it though if you want to. Now, try to login using your new username. If you see no problem, restart your computer and then login again as root in Tty. This time we’re going to automate GDM so you won’t have to login as root everytime you boot up before you can go the the graphical interface.

To do just that, you have to edit /etc/init/gdm.conf using vim (or nano). I suggest you create a backup of your gdm.conf file first, just in case you run into trouble along the way.

# cp /etc/init/gdm.conf /etc/init/gdm.conf.backup

# cd vim /etc/init/gdm.conf

By default this is what gdm.conf file in BT5 looks like:

# gdm – GNOME Display Manager

#

# The display manager service manages the X servers running on the

# system, providing login and auto-login services

description “GNOME Display Manager”

author “William Jon McCann “

start on (filesystem

and started dbus

and (drm-device-added card0 PRIMARY_DEVICE_FOR_DISPLAY=1

or stopped udevtrigger))

stop on runlevel [016]

emits starting-dm

env XORGCONFIG=/etc/X11/xorg.conf

script

if [ -n “$UPSTART_EVENTS” ]

then

[ ! -f /etc/X11/default-display-manager -o “$(cat /etc/X11/default-display-manager 2>/dev/null)” = “/usr/sbin/gdm” ] || { stop; exit 0; }

# Check kernel command-line for inhibitors

for ARG in $(cat /proc/cmdline)

do

case “${ARG}” in

text|-s|s|S|single)

plymouth quit || : # We have the ball here

exit 0

;;

esac

done

fi

if [ -r /etc/default/locale ]; then

. /etc/default/locale

export LANG LANGUAGE

elif [ -r /etc/environment ]; then

. /etc/environment

export LANG LANGUAGE

fi

export XORGCONFIG

exec gdm-binary $CONFIG_FILE

end script

Highlighted in orange are the codes that you need to remove for you to be able to automate GDM at bootup. Once you have trimmed the code, your gdm.conf file should now look exactly like this:

# gdm – GNOME Display Manager

#

# The display manager service manages the X servers running on the

# system, providing login and auto-login services

description “GNOME Display Manager”

author “William Jon McCann “

start on (filesystem

and started dbus

and (drm-device-added card0 PRIMARY_DEVICE_FOR_DISPLAY=1

or stopped udevtrigger))

stop on runlevel [016]

emits starting-dm

env XORGCONFIG=/etc/X11/xorg.conf

script

export XORGCONFIG

exec gdm-binary $CONFIG_FILE

end script

Now, restart your computer.

You should now be able to run X and login with your new username via GDM automatically. I’ve only used BT5 for like 2 days, but I think I’m going to like it.

Happy BackTracking! Cheers 🙂

.