Geekblok

Today a co-worker came to my desk with a rather simple but interesting question: “What software do you know that can encrypt a file or directory? The encrypted result needs to be sent abroad on a USB-disk.“

Without hesitating I answered that TrueCrypt could do the job, but then he replied: “Does that work on both Linux and IBM AIX?” (FYI: the data had to come from AIX and had to end-up on Linux). Ehr… Linux yes, AIX no. So I had to re-think…

Then I remembered OpenSSL is installed by default on (almost) all Unix-computers and this opened a new solution. In fact, it’s very simple.

First create a gzipped tar-file of the directory (where “/foo” is the directory containing all files to be encrypted):

# tar zcvfp /root/foo.tar.gz /foo

Next change the ownership to make it a little more secure by default:

# chown 600 /root/foo.tar.gz

Now we start encrypting the created tar-file using OpenSSL with the Blowfish-algorithm. When you press enter after the openssl-command you will be asked for a password. Keep this in mind and keep it secret. If lost there’s no way to recover your precious data!

# openssl enc -blowfish -in /root/foo.tar.gz -out /root/foo.tgz.bf</p> <p>enter bf-cbc encryption password:</p> <p>Verifying - enter bf-cbc encryption password:

You’ll end up with a file named “foo.tgz.bf” in root’s home-directory that is impossible to read and understand.

To decrypt this file one goes the other way around like this:

# openssl enc -d -blowfish &lt; /root/foo.tgz.bf | tar zxvf -</p> <p>enter bf-cbc decryption password:

Enter the password and tada, there’s your data!

Oh and my co-worker returned ten minutes later with a smile on his face.

You may have heard about OpenID before, or maybe seen the little icon popup at some sites already. Fact is that OpenID is slowly but steadily gaining popularity. And in my humble opinion, that’s a Good Thing™.

Let’s first look at what OpenID really is. It’s a system that allows you to authenticate yourself. Instead of your email address (which is commonly used), OpenID uses an URI as point of view.

How many accounts do you have online? 5? 10? 25? 100? 250? more? A lot of people (including me) don’t even know the amount of accounts anymore. It looks like every other website requires you to login and after a while you just loose track of all accounts, passwords and email addresses used. OpenID is very useful for this! It allows you to have one login, one password and all you need to remember is your own website’s address.

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A list of the top 10 best games ever should include Pong and Monkey Island (in my humble opinion). After listening to PRESS PLAY ON TAPE’s version of the Monkey Island theme (see a previous blog post), I felt the urge to play these awesome games again. There must be an emulator to play a game like that, right? So I can play these games on Linux, right? There is and it’s called ScummVM.

The name ScummVM stands for Script Creation Utility for Maniac Mansion Virtual Machine, so yeah, the abbreviation is a lot easier to remember. It’s described as:

ScummVM is a program which allows you to run certain classic graphical point-and-click adventure games, provided you already have their data files. The clever part about this: ScummVM just replaces the executables shipped with the games, allowing you to play them on systems for which they were never designed!

I was surprised to see how well this worked. Of course you need the original data files of the games (which of course I had laying around … somewhere online …). After loading up Monkey Island, the good old memories made me smile with nostalgia. The extremely funny game is still fun to play!

Other games that can be played through ScummVM include:

• Maniac Mansion
• Zak McKracken and the Alien Mindbenders
• Indiana Jones and the Last Crusade
• Loom
• Passport to Adventure
• The Secret of Monkey Island
• Monkey Island 2: LeChuck’s Revenge
• Indiana Jones and the Fate of Atlantis
• Day of the Tentacle
• Sam & Max Hit the Road
• Full Throttle
• The Dig
• The Curse of Monkey Island
• Simon the Sorcerer 1
• Simon the Sorcerer 2

And a lot more…

Oh sweet nostalgia!

This guide is the fourth part of the ssh guides. This time I’ll dig deeper into ssh-keygen. Most people use this program only for generating DSA or RSA keys for password less logins. But ssh-keygen can do a lot more (like most unix commands).

First I will have a look at generating those RSA and DSA keys, for we need that in following guides too. I suppose most people use it even for ‘empty-passphrase-logins’. Empty passphrases are killing your security, so please fill out some passphrase when generating your keys. I willl show that you only have to type it once every X-session that you login to your computer in a later guide.

So first of all generate a key if you haven’t done that allready: ssh-keygen -t dsa. Enter through de defaults, though do type in some passphrase you’ll remember.

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More and more tools are ported to the web. It all got started with e-mail (think hotmail), being thrown into a web interface. After that, instant messengers were ported (think meebo“) and not much later we’ve seen entire webbased Office Suites (think: zoho).

Now we see rapid development in the graphics area. An eye-pleasing example is Splashup. This tool/website looks very much like GIMP/Photoshop and it works fairly well (even running it in Firefox on a Linux system). With splashup, you can open files from your own PC (upload), Flickr, Facebook, Picasa or any webserver. Then you can edit the pictures from within your browser and upload them back, or download them to your machine.

It’s awesome to see a tool that allows you to work with layers and let you open multiple files at once. The tool, of course, can be improved (make a selection, use the Paint Bucket on that selection and see that the entire layer is colored…), but it’s fairly impressing already.

Definitely worth keeping an eye on!