Some reflections on trusting trust, and how deep the rabbit hole goes.

Poettering said that he does have a vision for how all of the security-related pieces of systemd are meant to fit together. He wanted to use his talk to explain ""how the individual security-related parts of systemd actually fit together and why they exist in the first place"".

[...] hard-learned patterns to write more defensive Rust code, learned throughout years of shipping Rust code to production. I’m not talking about design patterns here, but rather small idioms, which are rarely documented, but make a big difference in the overall code quality.

Windows 3 is often said to be just an UI on top of DOS. This article presents some of the inner side of Windows 3.x and will show that it is more ambitious and advanced than that.

Pipes are ubiquitous in Unix --- but how fast can they go on Linux? In this post we'll iteratively improve a simple pipe-writing benchmark from 3.5GiB/s to 65GiB/s, guided by Linux perf.

This blog post describes an alternative, straightforward approach to collaborative text editing, without Conflict-free Replicated Data Types (CRDTs) or Operational Transformation (OT). By making text editing flexible and easy to DIY, I hope that the approach will let you create rich collaborative apps that are challenging to build on top of a black-box CRDT/OT library.

This is a tutorial on how to build a digital implementation of a 2nd-order, continuously-variable filter (i.e. one where you can change the parameters runtime) that has dynamic behaviour that mimics an analogue filter.

In this deep dive post, I’ll explain how I used the interning design pattern in Rust to compress this data set by a factor of two thousand! We’ll investigate how to best structure the interner itself, how to tune our data schema to work well with it, and likewise how serialization can best leverage interning.

Last week, I built a tiny Linux system from scratch, and booted it on my laptop!

Macros, iterators, patterns, error handling and match make Rust almost perfect

Fuzz testing is a technique for automatically uncovering bugs in software. The problem is that it’s a pain to set up. Read any fuzz testing tutorial, and the first task is an hour of building tools from source and chasing down dependencies upon dependencies.
I recently found that Nix eliminates a lot of the gruntwork from fuzz testing. I created a Nix configuration that kicks off a fuzz testing workflow with a single command.

In this post, we are going to take a deep dive into pointer tagging, where metadata is encoded into a word-sized pointer. Doing so allows us to keep a compact representation that can be passed around in machine registers. This is very common in implementing dynamic programming languages, but can really be used anywhere that additional runtime information is needed about a pointer. We will look at a handful of different ways these pointers can be encoded and see how the compiler can optimize them for different hardware.

In this article we build off what we’ve already learned about io_uring and extend that to build an async echo server.

The underlying problem we are facing here with all these examples is the same: having the same set of bits which can mean two different things and needing some way to distinguish those two meanings. Failure to do so leads to ambiguity at best and serious defects at worst. That's why you see so much emphasis in modern systems on type safety and on strict domain separation between different meanings.

JTAG for Reverse Engineers

TL;DR: A world first reverse engineering analysis of AWS Session Tokens. Prior to our research these tokens were a complete black box…