So, how does ping.exe actually send a ping? It seems unrealistic that ping.exe itself implements all the protocols involved in sending a ping. So it must be calling some sort of library. Also, since it ends up talking to the outside world via a NIC (network interface controller), the kernel is probably involved at some point.

In reading files the hard way - part 2, we learned about dynamic libraries (like libc), and the Linux kernel, and how syscalls allowed us to ask the Linux kernel to do our bidding. For this series, we’re going to have to look at the Windows equivalents.

In the previous chapter, we’ve written a Dockerfile to build the catscii service inside Docker. The result is a container image that can be pushed to production!

In the last article, we found where code was hiding in our samples/hello executable, by disassembling the whole file and then looking for syscalls.

Later on, we learned how to inspect which memory ranges are mapped for a given PID (process identifier). We saw that memory areas weren’t all equal: they can be readable, writable, and/or executable.

In Veronica Mars and password hashes, from my new Tech As Seen On TV series, we’ve explored “cracking passwords” using brute-force methods, and then using rainbow tables, which was much, much faster.

But how do rainbow tables actually work? Let’s start at the beginning.

What’s a password hash?

A very simple design for an authentication system is to store passwords in clear text, say, in a file named password.txt:

Despite their peaceful appearance, game developers actually lead thrilling lives! Here are three things I learned (or re-learned) about yesterday that I’d like to share with you, in the form of assumptions that revealed false.

VSync is relatively straightforward. Right?

As an obsessive-compulsive, bipolar, perfectionist game dev, getting your game to run smoothly on all kinds of operating systems, graphics cards, and drivers combination is something of a holy grail. Many look for it, but let’s be honest here, it never really turns out as expected.

The year is drawing to a close, and I’m going off on a much-needed holiday next week. This seems like a good time to look back at the past twelve months!

I can’t believe that shipped

2018 was the year of foundational work. As far as “work work” is concerned, I spent the first 9 months finishing up my largest project ever, the itch v25 rewrite.

Welcome back!

In the last article, we did foundational work on minipak, our ELF packer.

It is now able to receive command-line arguments, environment variables, and auxiliary vectors. It can parse those command-line arguments into a set of options. It can make an ELF file smaller using the LZ4 compression algorithm, and pack it together with stage1, our launcher.

I have obsessed about this long enough, I think it’s only fair I (and you!) get some content out of it.

When I started writing this article, I was working on my P99 CONF slides. Those slides happen to include some bits of code. And because I’m a perfectionist, I would like this code to be syntax highlighted, like this:

let addr: SocketAddr = config? ln = addr? config

When I launched my Patreon, I vowed to explain how computers work. But in 2019, computers rarely work in isolation. So let’s take the time to write a few articles about how computers talk to each other.