Inspecting the Source of Go Modules

Go has indisputably the best package integrity story of any programming language ecosystem. The Go Checksum Database guarantees that every Go client in the world is using the same source for a given Go module and version, forever. It works despite the decentralized nature of Go modules, which can...

You Should Run a Certificate Transparency Log

Hear me out. If you are an organization with some spare storage and bandwidth, or an engineer looking to justify an overprovisioned homelab, you should consider running a Certificate Transparency log. It’s cheaper, easier, and more important than you might think. Certificate Transparency CT is on...

The FIPS Compliance of HKDF

HKDF is an HMAC-based key-derivation function specified in RFC 5869. It’s nice and we generally like using it. FIPS Federal Information Processing Standards is used generally as a moniker for the set of standards, recommendations, and guidance published by the U.S. National Institute of Standards...

Cross-Site Request Forgery

Cross-Site Request Forgery CSRF is a confused deputy attack where the attacker causes the browser to send a request to a target using the ambient authority of the user’s cookies or network position.1 For example, attacker.example can serve the following HTML to a victim and the browser will send ...

go.sum Is Not a Lockfile

I need everyone to stop looking at go.sum, especially to analyze dependency graphs. It is not a “lockfile,”1 and it has zero semantic effects on version resolution. There is truly no use case for ever parsing it outside of cmd/go. go.sum is only a local cache for the Go Checksum Database. It’s a...

Building a Transparent Keyserver

Today, we are going to build a keyserver to lookup age public keys. That part is boring. What’s interesting is that we’ll apply the same transparency log technology as the Go Checksum Database to keep the keyserver operator honest and unable to surreptitiously inject malicious keys, while still...

A Retrospective Survey of 2024/2025 Open Source Supply Chain Compromises

Lack of memory safety is such a predominant cause of security issues that we have a responsibility as professional software engineering to robustly mitigate it in security-sensitive use cases—by using memory safe languages. Similarly, I have the growing impression that software supply chain...

Opaque, Interoperable Passkey Records (and a Go API)

Passkeys are the most important thing happening in information security right now because they are the only principled solution to the overwhelming effectiveness of phishing attacks. Just like memory safety is the only principled solution to memory corruption attacks. Unfortunately, implementing...