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Off-the-Record Messaging

Thanks to a friend of mine, who uses Mac, I recently discovered 'Off-the-Record Messaging':

Off-the-Record (OTR) Messaging allows you to have private conversations over instant messaging by providing:

Encryption
No one else can read your instant messages.
Authentication
You are assured the correspondent is who you think it is.
Deniability
The messages you send do not have digital signatures that are checkable by a third party. Anyone can forge messages after a conversation to make them look like they came from you. However, during a conversation, your correspondent is assured the messages he sees are authentic and unmodified.
Perfect forward secrecy
If you lose control of your private keys, no previous conversation is compromised. Source

Simply install the pidgin-otr plugin through Synaptic, activate it in Pidgin and you can chat securely. (You can exchange 'fingerprints' with your friends and verify them).

Some more info from Wikipedia:

Off-the-Record Messaging, commonly referred to as OTR, is a cryptographic protocol that provides strong encryption for instant messaging conversations. OTR uses a combination of the AES symmetric-key algorithm, the Diffie-Hellman key exchange, and the SHA-1 hash function. In addition to authentication and encryption, OTR provides perfect forward secrecy and deniable encryption. This is different than the "off the record" setting in Google Talk, which merely disables logging.

Continued

Network Manager + VPN + Wireless = no go in Ubuntu 7.10

I am a little frustrated with Network Manager in Ubuntu 7.10. I have configured a VPN connection to Relakks.com, however I cannot connect to Relakks.com when I am using wireless. The only time Network Manager connects successfully is when I am using a wired connection.

In Ubuntu 7.04 I used the exact same set-up and it worked in both wired and wireless mode. But so far this is not working in Ubuntu 7.10.

The error I get is this:

From /var/log/syslog:

Oct 31 22:46:58 ubuntu NetworkManager: nm_vpn_service_process_signal():
VPN failed for service 'org.freedesktop.NetworkManager.ppp_starter', signal
'ConnectFailed', with message 'VPN Connection failed'.
Oct 31 22:46:58 ubuntu NetworkManager: VPN service
'org.freedesktop.NetworkManager.ppp_starter' signaled state change 3 -> 5.
Oct 31 22:46:58 ubuntu NetworkManager: VPN service
'org.freedesktop.NetworkManager.ppp_starter' signaled state change 5 -> 6.
Oct 31 22:46:58 ubuntu NetworkManager:
nm_vpn_service_stop_connection(): (VPN Service
org.freedesktop.NetworkManager.ppp_starter): could not stop connection
'Relakks' because service was 6.
Oct 31 22:46:58 ubuntu pptp[6190]: anon log[callmgr_main:pptp_callmgr.c:255]:
Closing connection (shutdown)
Oct 31 22:46:58 ubuntu pptp[6190]: anon log[ctrlp_rep:pptp_ctrl.c:251]: Sent
control packet type is 12 'Call-Clear-Request'
Oct 31 22:46:58 ubuntu pptp[6190]: anon log[call_callback:pptp_callmgr.c:78]:
Closing connection (call state)
Oct 31 22:46:59 ubuntu pppd[6185]: Modem hangup
Oct 31 22:46:59 ubuntu pppd[6185]: Connection terminated.
Oct 31 22:46:59 ubuntu pppd[6185]: Child process /usr/sbin/pptp 83.233.183.2
--nolaunchpppd (pid 6186) terminated with signal 15
Oct 31 22:46:59 ubuntu pppd[6185]: Exit.

Update - November 6th 2007

After a lot of searching, and thanks to some recent feedback at ubuntuforums.org I am happy to report that I have found a solution.

It appears that in Network Manager (nm-applet 0.6.5) pptp is hard coded to use eth1 which is fine for wired connections. If however you wish to use wireless you need to change the label of eth0 to eth1 and vice-versa. You need to edit:

/etc/udev/rules.d/70-persistant-net.rules

Mine looked like this at first:

# This file was automatically generated by the /lib/udev/write_net_rules
# program, probably run by the persistent-net-generator.rules rules file.
#
# You can modify it, as long as you keep each rule on a single line.

# PCI device 0x8086:0x4223 (ipw2200)
SUBSYSTEM=="net", DRIVERS=="?*", ATTRS{address}=="**:**:**:**:**:**", NAME="eth0"

which i then changed to:


# This file was automatically generated by the /lib/udev/write_net_rules
# program, probably run by the persistent-net-generator.rules rules file.
#
# You can modify it, as long as you keep each rule on a single line.

# PCI device 0x8086:0x4223 (ipw2200)
SUBSYSTEM=="net", DRIVERS=="?*", ATTRS{address}=="**:**:**:**:**:**", NAME="eth1"


After a reboot I am now able to connect to VPN using wireless in Network Manager.

Ubuntu eats your laptop hard-drive…

... or maybe not.

According to an article at the Inquirer, certain mobility settings in Ubuntu can lead to highly increased load cycles on laptop hard-drives, thereby shortening the life-span of the drive:

According to the bugs forum at Launchpad, when you switch to battery power on an Ubuntu laptop the hard drive goes though a load cycle a minute.

A standard laptop can handle about a 600,000 cycles in its lifetime which means that you will need a new hard drive every 1.1 years.

Like many other Ubuntu users I was worried, since I use Ubuntu on my laptop. However after carefully reading the bug report at launchpad it is evident that there is no need for alarm.

In most cases, Ubuntu will be configured to disable laptop mode, since this sometimes leads to hanging on certain systems.

Have a look at your /etc/default/acpi-support

In my case laptop mode is disabled by default:

ENABLE_LAPTOP_MODE=false

Again, after reading carefully through the bug report, I installed the smartmontools by issuing:

sudo apt-get install smartmontools

And proceeded to monitor my load cycles while connected to AC and while using the battery with the following command:

sudo smartctl -d ata -a /dev/sda

Here are my results:

31.10 - 17:20 : 5749
31.10 - 17:22 : 5753 (up to here laptop is not running on battery)
31.10 - 17:25 : 5754 (from here on laptop is running on battery)
31.10 - 17:29 : 5755
31.10 - 17:34 : 5757
31.10 - 17:54 : 5758

So in my case, unless I am reading this wrong, or unless smartmontools is not running properly on my system, I do not see any worrying load cycles.

GNASHing my teeth in Ubuntu

After installing Ubuntu 7.10, I decided that this time round, I would try out GNASH (GNU Flash) the open source Flash player. So, when prompted to do so by Firefox, I selected the GNASH extension instead of Adobe Flash. Unfortunately this left a lot to be desired. GNASH just did not work on many sites, most notably YouTube. I also think that this was the cause for Firefox hanging very often.

I have removed the GNASH mozilla plugin and instead installed the Adobe Flash player plugin, so far I have not had any problems, and YouTube videos load fine. It seems the GNU Flash project will need some more time to iron out any issues. Hopefully future versions will work better.

Backing up and restoring Evolution files

I would like to post here my experiences with backing up and restoring files and settings for Evolution, for future reference.

Backup

I backed up my entire /home folder using my trusted rsync method.

Restore

1. Start Evolution, you will be greeted by the Setup Wizard, follow the steps and add an email account. Then shutdown Evolution again.

2. Copy the follwing files from your backup location to the respective folders in your /home folder:

~/.evolution/
~/.gconf/apps/evolution/
~/.gnome2_private/Evolution

3. Now this step I am not 100% sure about, but I think you need to restart Ubuntu, at least I only saw my contacts restored after restarting.

Manual Tasks

Unfortunately you will have to add all your email addresses manually, this method does not seem to restore them. If anyone has better experiences or tips, please share them.

Gutsy Gibbon first impressions

I was having trouble upgrading from Ubuntu 7.04 to 7.10, so after a few days of trying I gave up and decided to do a fresh install. I used this opportunity also to kill off my Windows XP partition, ever since switching to Ubuntu I have never really used Windows XP, I will probably install XP in VirtualBox and use it virtually.

Here are some quick observations of what's new in Gutsy (I'm using an Asus A6K laptop with a Turion 1.6GHz processor and 2GB of RAM, as well as an Nvidia Go 6200 with 128MB RAM):

1. Boot up time is a little faster, although only by a few seconds.

2. Contrary to all other Ubuntu releases since Dapper, in Gutsy the laptop fans run on the lowest speeds most of the time, even with the desktop effects switched on. This, for me, is one of the most important and appreciated improvements.

3. Desktop effects are switched on by default, although I am not sure if this is Compiz-Fusion, I'll have to look into that.

4. Suspend - getting there. In the past the laptop would not be able to get out of suspend, and the screen would be blank. Now I do get as far as having a log in window, but after I enter my password nothing happens. It works! This is probably the biggest improvement for me.

5. Battery times - I am not quite sure if the battery times have been improved. I do know that the new Linux Kernel is 'tickless' and that this should improve battery times. However the Turion is quite a power hog so maybe the improvements are negated on my system.

6. Look and feel - The font used by GNOME is improved, I am not sure what the proper terminology to use is, but font looks good.

7. Themes - all aspects of theming such as wallpapers, fonts, desktop effects etc.. have been unified under System > Preferences > Appearance. A great move IMO. This is also where you can play with the settings of the desktop effects.

That's it for now. I may add some screen shots later.

Update

8. In previous versions of Ubuntu, the 'eject' button on the CD Rom drive of my laptop did not work after I had inserted a CD, and the only way to eject the CD was to do so by right-clicking on the CD Rom icon and selecting 'eject'. I am happy to see that as of Ubuntu 7.10 the 'eject' button works also after I have inserted a CD. Very cool.