Buzzword bingo, or how to survive long meetings

Working in the IT industry can be very exiting. But not always. There is quite some communication involved when working in a team, and some of those meetings are filled with dull moments to get through, and I must admit that it is sometimes quite challenging to stay sharp and focused. Buzzword bingo may help you to stay sharp.

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Resizing multiple images

I’m sure there are easier ways, and better I assume, to reduce the size of multiple images at once. But there was some point in time where I couldn’t resist the urge of solving this myself using ImageMagick and Tcl/Tk. ImageMagick – for me – is just a bunch of nifty command line image processing tools. It allows you to not only modify existing images, but also create new ones, and do all sorts of awesome image processing.

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Encrypted FreeBSD USB boot disk

It appears that USB attached storage devices resemble what floppy disks were back in the nineties. Back then, transporting floppies from one computer to another was very common. Unintentionally spreading malware and losing disks also. The risk of spreading malware has also remained the same since then. Losing disks means losing data. Today, online (cloud) storage is replacing USB storage to some extent. Especially for transporting data from one computer to another. Cloud storage is not always the right solution for this purpose as some data may actually be confidential and should be kept private at all times. Encryption is a tool that can do just that. Data encryption was once strictly regulated and generally a time consuming process. Which made it more suitable for intelligence agencies, military and diplomats. Until Phil Zimmermann unleased PGP to the world. Nowadays, if you have a computer connected to the Internet, then you have easy access to really sophisticated encryption software. This post is about “transparent” full (hard) disk encryption using FreeBSD.

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Booting FreeBSD from a USB disk

Open source software has found its way in every corner of the IT industry. Which is great, as it provides possibilities that were otherwise to expensive to pursue. In general, there is (at least) one down-side to using open source software: Support. In some cases a company might offer you a community edition of their software in the form of Open Source software, allowing you to choose between a free, “as is” version or a full-blown – and paid for – enterprise edition of their software. The latter usually has a help desk or technical support team to help you, but with former you’re on your own. There’s nearly always some form of community to help you out, but in general that is all “best effort”. And some are very good, but results vary is my experience. So if you ever happen to be in the position where there is no else but yourself to provide support, you’d best double check first to see if the software matches requirements, or expectations (if requirements are missing). Obviously, this is best done before using it in an environment where people depend on it. All too often, features turn out to work different than expected, or have other side effects.

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Memoirs of email

Email. Practically everyone connected to the Internet has at least one email address. Not surprisingly: If you get connected to the Internet, one of the first things to do is inform your friends and family on how to reach you… by email. As soon as you start to receive spam, you know that at least someone got the message 😉

Once upon a time, I was given the opportunity to rethink, build, test and migrate the network gateway infrastructure and servers handling email for roughly 45000+ email accounts. Email is technically very diverse, but at its hart uses two protocols: The Domain Name System (DNS) and the Simple Mail Transfer Protocol (SMTP). Since email fulfills such a basic need in communication across the entire Internet, most people tend to think of it as “always there”, and “available” whenever needed. Migrating email related equipment from one to the other is not something to do without extensive preparation. This post is a high level summary. It’s here in case I need to refresh my memory, or just spread ideas about the subject.

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PFlogging 2.0

It’s no secret that I’m a big fan of computer systems that are running a Unix-like or Unix-derived operating system. There are quite a few around me right now, running FreeBSD, Linux-Mint and Mac OS X Lion. I have a couple more that I keep around in Virtualbox, but don’t use that often. What I really like about Unix , second to its excellent and massive documentation, is its logfiles. Nearly everything you can think of is – or can be – logged into a simple human readable textfile. One of the first things you’d learn using Unix is that syslog will handle logfiles for most of the entire system. Continue reading

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Brute force attacks from A to Z – part II (last)

Passwords are a regrettable nuisance. Perhaps even one of the most dreaded inconveniences of computer security. This last part will contain some very basic examples that will demonstrate brute force attacks on passwords. The beauty of a brute force attack is its simplicity by nature: test all combinations. Of course there are some clever tricks to speed up the search or, to be more accurate; increase the likelihood of finding the password. Continue reading

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Rotating photos automatically

Stuff you need to do that just sneaks up on you. I’m sure this has happened to the most of us. This article is about one of those that is really high on the list of the “things to fix” and can involve quite a bit of data. Which usually means that I try to put the task off for as long as possible since manual intervention works just as well, and large amounts of data make for a big impact when things go wrong. “Think it over, before trying to fix it”, is something I’ve learned to memorize over the years as an IT professional. Only this time I’m talking about rotating digital photo’s on my Mac, so they can be edited as they were taken. There is usually a lot of them, and you must examine every photo, because not all photos need to be rotated. Continue reading

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Brute force attacks from A to Z – part I

After reading and watching some very interesting views on the use of strong passwords, I must say that I don’t think we will ever be able to do without passwords. They’re here to stay. I’ll bet that the average person with an Internet connection has at least 10 passwords to remember these days. Most access methods, especially on the world wide web, rely on username-password combinations. Your web browser may take care of quite a few of them, which is a good reason why you should always update your web browser software. And even though there are some very good alternatives available, none of them are used as frequent as good-old passwords. It is widely known that you should take great care in selecting a password and change it every now and then, because you do not want a hacker to guess yours. Hackers receive quite a bit of media attention these days, and you don’t want to be on the list of their victims, right? Then you need a strong password, for starters. There are quite a few policies around on how to pick a password, each different from the other. All with the same goal: Keep your account secure. Or in general: To keep what is yours. Continue reading

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Creating FreeBSD jails disregarding the manual

Computer virtualization has been around for quite some time as any mainframe guru will tell you. If you search around the Internet for information on this subject, you’ll find tons of references to different types of virtualization. VMware, Virtualbox, Qemu and Xen allow you run practically any OS, but are quite demanding on the hardware you’re running them on. Operating system-level virtualization is a more lightweight version that doesn’t allow you to run a different OS, but the same OS inside the OS. FreeBSD makes use of this type of virtualization since version 4.0, released in march 2000. The use of this type of virtualization is theoretically endless, but given typical uses of FreeBSD this is mostly used as a feature-rich ‘sandbox’ environment; an environment that allows you to host services that are completely disconnected from other services on the same machine. In FreeBSD-speak these are called ‘jails’. If you were to run a program in a jail, it would be constrained to that particular jail and not be able to break out. If you lookup the FreeBSD manual page for ‘jail’, you’ll find that you can create one in just 6 commands. There is a downside to that method, because it’ll start to build binaries for the entire OS from scratch. Depending on your hardware, that might take a while! Suppose you were to work in a very secure environment that doesn’t allow Internet access, the use of USB drives or compilers to be installed, then you’d think that setting up a jail would be impossible. Continue reading

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