Signing HTTP Signatures in C++ using Botan (for ActivityPub)

DISCLAIMER: I am not a cryptographer. For your own sake, consult a cryptographer if you want to use the following code in production. I'm attempting to implement a basic ActivityPub server following Mastodon's tutorial. It's easy to follow and and explains everything clearly. However I got stock at the last step signing the HTTP signature....

A Dirty Introduction to Common Lisp for C++ users

I started learning Lisp a while back as a way of seeking inspiration from the first wave of AI systems. The road was rocky and I wish there's some resource comparing Lisp to a modern language... So this is one. I hope people could find this useful. As a bridge between C++ and Lisp. I...

Setting up GPU accelerated remote desktop with sound on headless Linux using NoMachine

I have always wanted to setup a remote desktop on my NAS. It feels really cool to have the exact same desktop anywhere. In lab, out side at a caffe, in lecture. But I've never got GPU acceleration working properly. While I can't rely on the puny Cortex-A72 cores to draw the entire desktop (it...

Building CERN ROOT on Arch Linux ARM

Mostly want to document how I'm building ROOT on ARM64 Arch Linux. The process it quite trivial but in case I forgot how to do it in the future. My ARM server runs Arch Linux. Which should come with ROOT in the official repository. But as you guessed, it didn't. Which indicates somehow ROOT builds...

The journey of running Arch Linux as an enterprise production server

So... When my last, recent contract work have reached the deployment phase. We found that our client is the only department in their entire enterprise that runs Windows Servers and Windows Servers only! Yet our code only runs on Linux and FreeBSD (and HaikuOS if you try really hard). We've never expected to have to...

Solving QCA6174 WiFi crashing, high ping, unusable on Linux

One glaring issue I have with my laptop (using a Qualcomm NIC) is the ridiculous high pings while using WiFi. > 400ms for some packets to reach a near by machine and back is totally unacceptable. It makes ssh unusably slow and even mosh on the edge of barely usable. The situation is so bad...

How to run FreeBSD/ARM64 in a VM on an ARM Linux server

COSCUP 2020 just ended and I learned a lot in the two days. One of the many cool things is that I can actually run FreeBSD on my server! So be it inside a VM. Whatever, it is still very cool to have actual UNIX running on ARM. Friends in the FreeBSD community at COSCUP...

HoneyComb LX2K update 1 – after 2 months

It has been 2 month since my last post about my ARM workstation/server. I think it's time for an update for how thing are going and if there's problems. In sort: no. There's not major issus with the board. NXP and SolidRun have done a very good job building it. Performance Without a doubt, the...

Rocking a 16 core ARM workstation for data analysis and NAS – HoneyComb LX2K

I preordered the HoneyComb LX2K workstation board last October and I has finally arrived and I finally got time to build my ARM workstation. The process is challenging and fun! Building of the machine The LX2K is a very capable 16-core ARM workstation board selling at 750$ (550$ when I ordered, early access price). Providing...

CERN ROOT tips and tricks

This is more of a note for myself. Over time, I've learned some useful fact about ROOT that I now wish I have known when I started using ROOT. Hopefully as a ROOT user, you could also find  some of these helpful. Tell ROOT to not show the startup banner You do: user@somepc:~$ root -l...