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Tech blog on web, security & embedded
Asynchronous programming is pretty weird. While it is straightforward enough to understand in principle (write code that looks synchronous, but may be run concurrently yada yada yada), it is not so obvious how and when async functions actually perform work. This blog aims to shed light on how that works in Rust.
In Dutch we have a saying 'meten is weten', which translates to 'to measure is to know'. That sentiment is frequently overlooked in setting up computers and networks.
At Tweede golf, we are working on modern implementations of time synchronization protocols in Project Pendulum. The ntpd-rs project is part of it, and we've recently implementend the draft specification of NTPv5, for which we built a test server at IETF 118. This blogs covers the what, why and how (including a 'how to run').
At the GOSIM Conference in Shanghai, last September, I had the opportunity to talk about ntpd-rs, our project implementing the Network Time Protocol.
Thanks to funding from NLNet and ISRG, the sudo-rs team was able to request an audit from Radically Open Security (ROS). In this post, we'll share the findings of the audit and our response to those findings.
We're proud to announce that 5 October 2023 marked the first stable release of ntpd-rs!
When we first introduced Rust 101 to you on our website, preparations for its first run where in full swing. The action started in February 2023; 20 students of the Faculty of Informatics and Information Technologies of the Slovak University of Technology in Bratislava followed 9 lectures and 9 tutorials, and worked on their own rust project to round off the course. The course was completed in May.
At RustNL 2023, a Rust conference held in Amsterdam recently, I had the opportunity to talk about ntpd-rs, our project implementing the Network Time Protocol.
For some time, we have been quietly laying the groundwork for a new implementation of sudo in Rust. Now we are excited to talk about it!

While working on the Roc compiler, we regularly dive deep on computer science topics. A recurring theme is speed, both the runtime performance of the code that we generate, as well as the performance of our compiler itself.

One extremely useful technique that we have been playing with is data-oriented design: the idea that the actual data you have should guide how code is structured.

TrustZone-m is a technology by ARM that allows you to create a Trusted Execution Environment (TEE) in your software. You can use it for example to keep your encryption keys secret or to separate a big vulnerable networking stack from your own code.

Over the last three months I've been working on a set of crates (Rust libraries) with the aim of making the usage of TrustZone-m a lot easier.

January 12, 2023

Crash! And now what?

Imagine you've just deployed an embedded device in the world and of course, you have tested it thoroughly and it works. To monitor the device, you've set up some logging.

In 2009 Rust was a new language. In 2022 that isn't true anymore. Nor does Rust have anything to prove. It's made it to the Linux Kernel, and Microsoft have dubbed it "the Industry’s Best Chance at Safe Systems Programming".
I’ve organized a couple of Rust meetups in The Netherlands this year, and last was not least. On Nov 30 we had four very interesting talks and a cool crowd at the Rust in critical infrastructure meetup in Amsterdam. A round-up.

For the last couple of months we at Tweede golf have been working on implementing a Network Time Protocol (NTP) client and server in Rust.

The project is a Prossimo initiative and is supported by their sponsors, Cisco and AWS. Our first short-term goal is to deploy our implementation at Let's Encrypt. The long-term goal is to develop an alternative fully-featured NTP implementation that can be widely used.

For the last couple of months, we've been working on a Rust implementation of the Precision Time Protocol called Statime ("statim" is Latin for immediately), and we're proud to announce the completion of the first phase of the project.
Most of our web applications use either Node.js or Symfony for their server-side part. Both offer a lot in terms of productivity. But every now and again, when you look at the computing power used or the amount of time a simple HTTP request takes, you can't help to think "what if..?".
Sending documents over the internet can be a pain. Email providers generally support attachments with a maximum size between 10 and 50 MB, for larger files one would need to find another way. Most people would probably use one of the many public cloud or file sender solutions. But what if the files to be sent contain personal information, medical information or are private family photos? And how do you know that only the recipient can access and download these files?
It is common wisdom that one should avoid implementing their own cryptography if at all possible. This is generally good wisdom as writing correct cryptography code can be very tricky and takes quite a bit of time to get done right.
As owner and technical lead of our company I'm very motivated to keep up to speed with all new developments and to continuously innovate our tech stack. Nevertheless, every once in a while I find myself lacking in in-depth, hands-on experience in languages and tools I really want to be on top of. At that moment, I know I need to hit pause and take the time for a deep dive, in the form of a personal learning project.
KubiKey as a project started out with one main goal: streamline and make more secure the process of accessing the kubernetes cluster used by Tweede golf.
Welcome to the age of communication. It's 2021 and technology has come a long way. People, large machines and small devices communicate more intensively than ever before, and many technologies to enable them to do so have been developed. Some of those technologies use physical pathways like fibreglass to reach their receivers, others use radio signals to send messages. It's these wireless communication technologies that spark the imagination the most.

Concurrency isn't easy and implementing its primitives is even harder. I found myself in need of some no-std, no-alloc Rust async concurrency primitives and decided to write some. I kept the scope small so even you and I can understand it. Even so, it still involved futures, wakers, atomics, drop and unsafe. I'll introduce each of those to you while building a simple primitive. At the end, you will be able to implement your own primitives!

With the current pandemic situation, it is hard to hold meetings at an appropriate and safe distance. Looking for secure alternatives, our local city government approached Tweede golf with developing a novel authenticated variant of videoconferencing, with the intention of holding city council meetings using this solution.

The Dutch government offers the AHN [[1]](https://www.ahn.nl/) as a way to get information about the height of any specific place in the country. They offer this data by using a point cloud. That is, a large set of points with some additional meta information. With the current version of the AHN the resolution of the dataset is about eight points per square meter. This results in about 2.5TB of compressed data for the relatively small area of the Netherlands. While this is something that is not impossible to store locally, it does offer some challenges.

The API documentation of cloud storage providers can be quite intimidating. If you are simply looking for a few straight forward storage actions these extensive APIs might seem a bit overkill. Another hurdle is that storage providers define their own distinctive APIs.

One of our clients helps companies in becoming GDPR-compliant. A goal is to recognize sensitive pieces of user data in a big pile of registrations, receipts, emails, and transcripts, and mark them to be checked out later. As more and more data is collected by companies, finding and eliminating sensitive data becomes harder and harder, to the point where it is no longer possible for mere human employees to keep up without assistance.

At Tweede golf I've been working with Rust a lot lately. My interest in Rust has been there for years, so I was very happy to start applying it in my working life, about a year ago. Since then I have worked with Rust both for our clients as well as employing it for our operations setup. I have also experimented with Rust for web [1]. Until now however we did not contribute to the Rust ecosystem. About time that we get our feet wet and publish our first crate!