Another poor sysadmin
An ordinary BOFH

The solution (or just a solution).

  apt-get install note

After installation, uncompress and copy the file /usr/share/doc/note/examples/noterc.gz to $HOME/.noterc. Then edit it to your liking. You need this if you want to enable encryption or disable the interactive mode (interactive mode sucks).

Now, you can keep notes at any time by just running note in one of your open xterms (or open one more). You can search your notes with -s argument. And you can organize your notes by topic, just by add ing your topic in the first line of a note quoted inside slashes.

Works great when compined with other shell utilities, especially grep.

This line is needed or else... null exception

Oops, not quite yet. These wireless A/V devices are using the free band at 2.4 Ghz and in this place there is a festival of telecommunication airwaves. Unfortunately, there was a lot of noise and there was no way somenone could enjoy a movie in this quality. Especially when using the microwave oven.

WiFi standard for wireless LANs is divided to 14 channels. The "good" channels 1,6,11 and 14 are already used. There is a fair amount of signal in channels 1-5 from various wireless APs in the close vicinity. Channel 6 is used by my indoor router. And channel 11 is used by another indoor router that belongs to one of my neighbours. Channel 14 is not legal in my country.

The A/V transmitter has only four channels available that are propably an equal division of the range 2.40-2.48 Ghz. None of them seemed to be unaffected by all this wireless network traffic. Then, I had an idea. My neighbour's wlan was unecrypted with free access, and I knew his router had the default password for its' administration interface ;-) . So I connected to his/her network, accessed the administration interface and changed the channel used from 11 to 1. Well, I figured that if s/he had let MS Windows to control the WiFi pccard s/he wouldn't notice any change since channel resolution in this case is automatic.

After that, the receiver was working fine in the 4th channel and finally I could happily watch the 'Pirates of Silicon Valley'.

What the heck this has to do with aircracking? A couple of days later the reception was bad again. I checked by scanning for networks and found out that my neighbour was using channel 11 again, and this time with WEP encryption. I guess, me changing the channel of his router did cause a problem to him/her. S/He must of contact the technicall support of his/her DSL provider which then advised him to use WEP encrytpion just as a precaution.

First, I solved the problem of the A/V reception by changing my own router's channel from 6 to 1 and my A/V transmitter to the 3rd channel (somewhere between channel 6 and 11 for WLANs) and then experimenting by placing the A/V transmitter and receiver in various locations until the received picture was clear. I actually got a nice result with the only disadvantage that my A/V receiver is now hanging on the edge on top of my TV.

And then, I was curious to see how secure WEP is. It is known to have very poor encryption that is easily exploited.

apt-get install aircrack.

Aircrack is a set of tools for hacking wireless networks. To crack a WEP encrypted signal someone first has to gather enough packets (or ivs) from the encrypted network by using the airodump tool. Then, aircrack tool analyzes the packets and calculates the encryption key.

Yesterday I left my laptop in airodump mode all day. When I came back home in the evening, airodump had gathered enough packets to crack a 128bit WEP key. It took less than two seconds for aircrack to provide me with a five bytes long hexadecimal key. My neighbour, typicall lame user, didn't bothered to think of a 128bit key (needs 11 characters instead of 5). What a surprise, s/he didn't even changed the default password for administration interface of his/her router.

This time though, I didn't mess with his/her settings, this was only for educational purposes (Actually, it was too easy to be of any other educational gain than that WEP is completely useless). Maybe I have to find out who is this neighbour and then use some of Kevin's social engineering to pursuade him/her to change the channel because it interferes with my A/V signal.

A small accident (photos).

The previous php app that I had worked on, I gave a shot at Sourdough. it seemed like a promising framework, implementing a flyweight design with PHP5's new Object Model. But it lacked of good documentation and I had to spend a lot of valueable time to solve the riddles. I really regret that choice.

Now, I chose the Symfony project. Symfony has a LOT of documentation and very good examples and tutorials. It is very similar to what the Apache Turbine is for java webapps. It integrates propel which works much like torque, and phing that's similar to apache ant. All requests are made with smart urls through a front controller. A development version of the front controller gives you debuging info and there is also support for unit testing. An application controls or presents its' data by using modules that take actions. This is exactly like the MVC design implemented in Apache turbine project.

The problem is that there's not enough time left for experiments as I have to have a complete working application in less than two weeks. And I've already lost enough time developing a part of the app in standard php that must be reimplemented in the new and unfamiliar yet framework.

Ok, going back to work now.

A greek proverb says that beginning is half of everything. I guess today, starting this blog is equal to writing everything else I'm going to post here.

I work as a systems administrator in a laboratory of Mechanical Engineering at Aristotle University of Thessaloniki. Despite that my job description is "Administration of Network Infrastructure" my real job profile is administration of everything except economics (sometimes I wish it was the other way around). Just for not trying to exaggerate, my every day tasks include administration of user accounting, technical support, networking, linux/unix and windows. Also programming, web designing, graphics manipulation and last everything that requires a screw driver or a hammer.

My hobbies are near the above activities with the addition of computer gaming. I was a fairly good quake3 player... in general I prefer FPS games and maybe some adventures. I also am a member of a dark underground community known as WTHESS, it's about creating an amateur but yet a stable, reliable and secure wireless network over the roofs of the city Thessaloniki (for more info on the later see http://www.wthess.net).

Anyway, I intend to write in any of the two languages (Greek & English) that helps me express myself better. Most of the entries in this blog will be technical stuff from my experiences with Linux or any other system, from software development and other stuff like that.