A day in the life of…

Linux, and other unices have an excellent system to centralize log events. This is done through syslog. This system removes the need for every application to maintain their own log files and let the syslog server handle all the events. Depending on the type of event that is logged, it can take additional action like [...]

From time to time I get amazed how people can setup their production servers. At the smallish development companies there is no real system administrator available to setup the systems and to keep them up to date. Now I’ve seen systems that have been setup ranging from “somebody with sufficient knowledge” to “this-was-setup-by-the-janitor” and everything [...]

I was on the verge of creating a post about the TSL/SSL handshaking, when I discovered a blogpost about the very same subject. Since I don’t think it’s of much use to blog about exactly the same thing, and I can really recommend Jeff Moser’s page so please read and understand it. http://www.moserware.com/2009/06/first-few-milliseconds-of-https.html So I [...]

Oauth is a very popular authentication mechanism used for a lot of web applications. And not without good reasons. It is relatively easy to implement, has different flavours (2-legged, 3-legged system) so you can use almost anywhere that requires authentication and authorization. This post is not about how to implement oauth. That can be found [...]

SSL & virtualhosting on 1 IP address? I can’t be done! Well, this might have been the case a few years ago but times has changed. Let’s explore the possibilites to have multiple hosts running on the same IP address AND all of them have their own separate SSL domain and certificates. It’s possible, but [...]

Did you know you can write a webserver in awk or that sed supports conditional jumps? Probably not… These tool (languages, actually) are much more powerful than most people know. The sed & awk combination gives you massive power IF used correctly. Although most people use it for simple tasks like search/replacing or displaying certain [...]

Today I overheard two colleagues discussing one of my favorite subjects: encryption. The discussion was about that encrypting data (with a normal block cipher) was working perfectly in ECB mode, but not in CBC mode. So, this all leads up to the question: what is ECB and CBC? And when should you use them? Although [...]

I’ve just uploaded the new slides for my Public Key Cryptography 101 presentation. It consists of 84 (!) slides about the basics of encryption, public key cryptography and implementations. How does it work, what are it’s advantages, disadvantages and practical uses. Off course, this presentation should be accompanied with the talk itself and I’ve submitted [...]

Most developers who are working at the command line on a Linux system know the “basic” commands: ls, cd, cat, tail, head, sort, grep, find and others. More “advanced” users will know how to deal with the ‘sed’ and ‘awk’ beasts, or even prefer perl-oneliners. Have the knowledge of bash (scripting) and you find yourself [...]

During this blog post I will talk about creating your own custom package repository. However, before you can setup a repository, you need packages. This previous post talks about setting up your custom packages.