Posts

An Introduction So, I’m moving into an apartment in the near future. Following that, I will have to learn how to manage my documents and ensure I can find them back in time. I’ve thought of a few solutions, one of them being what I do now – where I simply have a folder with PDFs of my documents (I digitalize everything). This works fine now… (I have like … 20 documents)… But it may not work in 2 years when I have a hundred documents spread over many different corporations and years. ...

I’ve long wanted to write a Bencoding library. Bencoding is an encoding format for encoding objects like text, lists, dictionaries, etc., into a single piece of text. It’s often used for transporting configuration files. Bencoding is most famous for its use in the Bittorrent protocol—it forms the basis for .torrent files. I wanted to create a C# library to support all known Bencoding object types. You can read more about the encoding here. ...

Introduction For my previous post, where I find the signal strength of WiFi spots, I also needed an algorithm to actually locate the spot. I decided to use triangulation, which is commonly used in wireless communications to locate devices based on signal strength from known positions. As my system uses GPS, I had to consider the Earth’s curvature. Calculating the geographic midpoint on a sphere isn’t trivial, but GeoMidpoint provides a great explanation (Method A). ...

Introduction I’ve long wanted to build a WiFi-based application—ideally one that also records GPS location data for wardriving. I searched for manageable C# solutions integrated with .NET. First Attempts I explored many WMI tutorials, but on Windows 7, I lacked the needed namespaces like MSNdis_80211_ServiceSetIdentifier. Eventually, I discovered the WLan API (available since Windows XP SP3), usable via P/Invoke. Fortunately, someone made a ManagedWifi wrapper for it—perfect! The Scanner I wrote a small utility that scans for SSIDs across all interfaces and retrieves their MAC addresses. ...

I was reading several articles about the new NemID system in Denmark, and concerns around how organized groups might generate valid CPR numbers and brute-force passwords. This could lead to account lockouts—potentially paralyzing major parts of the country’s digital infrastructure. To test this, I created code to generate valid CPR numbers based on known rules. The Rules The original rules were based on a textbook I no longer have, but I found newer ones via this blog post, official article, and PDF document from the CPR register. ...