Yesterday’s CTF of the 25C3 resulted in a very respectable 2nd place of the team “h4ck!nb3rg” from Hagenberg. It was an amazing experience being part of this! Thanks to the team and everyone involved in the organization of the event!
Category: computer
My initial git settings for any repository
This is my cheat sheet for the settings I use for my git-repositories (list to be edited continuously):
Global settings:
git config –global user.name Martin Carpella
git config –global user.email xxx@yyy.invalid
git config –global color.ui auto
Per-repository settings:
git config core.autocrlf true
git config core.safecrlf true
Per-repository .gitignore for Visual Studio/C# projects:
bin
obj
*.user
*.suo
Thumbs.db
Missing dictionaries on OpenOffice.org 3
I just upgraded to OpenOffice.org 3 and I really like it. But there was a small, but very anoying problem: OO.org seemed to be unable to find any dictionaries. I found out rather quicky, that starting with OO.org 3 dictionaries are only available as extensions. Well, basically this is no problem, but the English (at least the US and GB variante) are supposed to be bundled with the installer and are not available as seperate extension.
It seems there is a little bug with the installation on Vista under certain circumstances which causes the extensions not being registered properly with OO.org.
To solve the problem, follow the same following steps:
- Locate your OO.org “install” directory of your installation, usually it is C:\Program Files\OpenOffice.org 3\share\extensions\install” [Updated 2008-12-21 to include “extensions”, thanks to the anonymous commenter!]
- Manuylla install the appropriate dictionary extension (“dict-en.oxt”, “dict-de.oxt”, “dict-fr.oxt”, “dict-it.oxt”) by either launching the oxt directly or by chosing Tools -> Extension Manager.
For me this worked after restarting OO.org totally (i.e. closing down all Writer, Calc, …).
A first look at Google Chrome
Just played around with Google Chrome. First impression: Wow! This is definitely going to encourage development of other browsers as well!
It feels lightweight, fast for JavaScript applications, and offers some nice features (I especially like the possibility to open an “anonymous window” which will forget all cookies etc. when being closed without being forced to delete all other cookies as well.) Tabs can be dragged out and dropped back into the browser, something I’d always wanted Firefox to be able as well.
Each tab runs within its own process and Chrome offers a “Task Manager” (Shift-Esc), which will display memory usage, CPU usage and bandwidth consumption for each tab, which I consider very handy.
Chrome is available for Windows only at the moment, but is expected to be released for MacOS X and Linux as well. I am really curious how this is going to develop and if this is going to really affect “the Internet as a whole” (I really believe Google has gained enough market power to push their products).
Nice to know – Volume 2
udev renames you network interfaces
Sometimes udev renames your devices. This happened to me when upgrading a server, eth0 suddenly became eth1 and vice-versa. Of course, this broke nearly all firewall scripts on the server… There is a nice explanation how to get udev to name your devices the way you want.
Visual Studio 2005 Service Pack 1 on Microsoft Windows Server 2003
When installing Visual Studio Service Pack 1 under Windows Server 2003, it might fail because it cannot verify the signature. You should take time and visit the link provided in the error message, because it will take you to a hotfix that will correct the problem.
(via Mark Caroll’s Blog)
VMWare Server on Ubuntu 8.04
A nice tutorial for getting free VMWare Server 1.0.5 running on Ubuntu 8.04.
Nice to know – Volume 1
As I definitely should post more on my blog, I now try to start a new series: “Nice to know”. It will be a collection of interesting things I consider memorable but which don’t deserve their own blog-post.
Trickle
Tricke allows you to limit bandwith for processes that do not support bandwith limitation out-of-the-box. It works by preloading and simulating the socket API. You use it as a wrapper when starting the process, like trickle -d 80 someapp.
You can use it to limit rsync speed for instance (thanks to http://www.yak.net/fqa/404.html): rsync -auvPe “trickle -d 80 ssh” user@host:/src/ /dst/
VMWare Tools and Kernel 2.6.24
VMWare Tools out of the box do not install on kernel 2.6.24 (as used in Ubuntu 8.04 for instance). A possible solution is described here. It is based on using the open-source version of the VMWare tools (open-vm-tools).
Test-driven network management
Test-driven development has proven to increase quality of software in many cases. I believe that the same principle should be applied to network management. From time to time, I am occupied in managing quite large and distributed networks, consisting of many different network segments, routers, servers, etc.
Primary tool in managing any network is using monitoring software which tells you if everything is alright or if you should worry. For various reasons I have become a huge fan of Nagios for monitoring networks I am responsible for, especially for the simple extensibility by writing your own check scripts (plugins).
While working through some issues in a network, I suddenly decided to try an approach I spontaneously called “test-driven network management”¹. The steps are easy (and are a one-to-one translation of agile software-development principles):
- Write a Nagios test which checks for the requested/required feature.
- This test will fail.
- Implement a solution satisfying the test.
The same advantages of automated testing (better: unit testing) in software development also apply to the network management tasks:
- The test documents what you want to achieve in a quite formal way.
- You will (almost) immediately know when your solution breaks other requirements (if tests exist for them).
- As networks tend to be even more fragile then software, you have to monitor whatever you implemented anyways 🙂
Whenever possible, I try to add a test (or tweak an existing one) for any trouble-ticket / feature request I come around. In my experience, customer satisfaction tends to increase, because you start noticing problems before they do and you also implement measures to prevent the same problems to occur over and over again.
¹ I am quite sure there is another technical term for it, as I am quite sure I am not inventing anything new here… If you know how this is called by others, please tell me in the comments.
[tags]development, network, sysadmin, network management, test-driven development, nagios[/tags]
TrueCrypt 5.1 is out!
The new TrueCrypt 5.1 version finally enables hibernation with pre-boot authentication. I am going to try it out as soon as possible. A big thank you to all the developers!
Update 2008-03-16: Today I finally had time to test out pre-boot authentication. It simply worked great. No problems at all. As I was using it on a notebook, I was very happy about the possibility to interrupt and resume the encryption process.
[tags]encryption, windows, truecrypt[/tags]
TrueCrypt 5 is out!
After quite some time, a new version of my favorite encryption tool is out: TrueCrypt developers have released version 5 of their product, introducing a new killer feature (among others): System Volume Encryption with pre-boot authentification (only Windows 2000/XP/Vista). This means, that TrueCrypt will encrypt everything on your system drive, including page- and hibernation file, finally making hibernation a safe and easy possibility.
I am going to look into this next week, as I need my notebook on Saturday (just in case anything goes wrong).
Update 2007-02-08: As my first commenter below points out, it seems hibernation is disabled by TrueCrypt while having your system partition encrypted. I don’t really understand why at the moment, but I will investigate further. For me this is a primary show-stopper, as this was the long-awaited functionality I was waiting for.
Nitpickers Corner¹: Of course I am aware why encryption and hibernation in general are no-goes together, but I don’t understand why this is an issue when full-system encryption is enabled.
Update 2007-02-08 (again): Ok, in this TrueCrypt forum thread they explain why they cannot support it at the moment: Windows treats the hibernation file differently, it seems to bypass the TrueCrypt driver and therefore would still write keys to disk without encryption. Ok, still get to wait for my dream feature then, but I still refuse to buy PGP 🙂 Thanks to the developers for their great work anyhow!
¹ a tribute to Raymond Chen 🙂
[tags]security, encryption, truecrypt, windows, linux, osx[/tags]
CrossLoop: Free and easy remote assistance
Today I had to give quick support to a colleague working from home in order to resolve a networking issue. This was the perfect situation to evaluate CrossLoop, a free remote-assistance tool similar to NetViewer (but, as mentioned, free).
The experience was nice, it just worked “out of the box”, after installing and sending me the access key, the connection was established despite our firewalls in between. It is easy enough I would trust almost all customers to get it working. I’ll have to evaluate how the software behaves if you don’t have administrative privileges on your system.
Crossloop is based upon TightVNC and as a consequence you get the typical feeling of a VNC session, which is not as fluent as NetViewer, Remote Desktop, or similar, but it was more than enough to work on the issue at hand.
So if you are searching for a low-cost (i.e. free) alternative for quick support of family members, co-workers, or even customers, you should give CrossLoop a try. CrossLoop currently is only available for Windows, but Linux and Mac versions are planned.
By the way, CrossLoop just got a 3-Million-$ Series A investment, so hopefully this service will continue to exist for some time.
[tags]vnc, crossloop, remote access, software[/tags]