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William Woodruff

Attestations: A new generation of signatures on PyPI

For the past year, we’ve worked with the Python Package Index (PyPI) on a new security feature for the Python ecosystem: index-hosted digital attestations, as specified in PEP 740. These attestations improve on traditional PGP signatures (which have been disabled on PyPI) by providing key usability, index verifiability, cryptographic strength, and provenance properties that bring […]

Our audit of Homebrew

This is a joint post with the Homebrew maintainers; read their announcement here! Last summer, we performed an audit of Homebrew. Our audit’s scope included Homebrew/brew itself (home of the brew CLI), and three adjacent repositories responsible for various security-relevant aspects of Homebrew’s operation: Homebrew/actions: a repository of custom GitHub Actions used […]

We build X.509 chains so you don’t have to

For the past eight months, Trail of Bits has worked with the Python Cryptographic Authority to build cryptography-x509-verification, a brand-new, pure-Rust implementation of the X.509 path validation algorithm that TLS and other encryption and authentication protocols are built on. Our implementation is fast, standards-conforming, and memory-safe, giving the Python ecosystem a modern […]

Our audit of PyPI

This is a joint post with the PyPI maintainers; read their announcement here! This audit was sponsored by the Open Tech Fund as part of their larger mission to secure critical pieces of internet infrastructure. You can read the full report in our Publications repository. Late this summer, we performed an audit […]

Adding build provenance to Homebrew

This is a joint post with Alpha-Omega—read their announcement post as well! We’re starting a new project in collaboration with Alpha-Omega and OpenSSF to improve the transparency and security of Homebrew. This six-month project will bring cryptographically verifiable build provenance to homebrew-core, allowing end users and companies to prove that Homebrew’s packages come from the official Homebrew CI/CD.

ABI compatibility in Python: How hard could it be?

TL;DR: Trail of Bits has developed abi3audit, a new Python tool for checking Python packages for CPython application binary interface (ABI) violations. We’ve used it to discover hundreds of inconsistently and incorrectly tagged package distributions, each of which is a potential source of crashes and exploitable memory corruption due to undetected ABI differences. It’s publicly […]

We sign code now

Sigstore announced the general availability of its free and ecosystem-agnostic software signing service two weeks ago, giving developers a way to sign, verify and protect their software projects and the dependencies they rely on. Trail of Bits is absolutely thrilled to be a part of the project, and we spoke about our […]

High-fidelity build instrumentation with blight

TL;DR: We’re open-sourcing a new framework, blight, for painlessly wrapping and instrumenting C and C++ build tools. We’re already using it on our research projects, and have included a set of useful actions. You can use it today for your own measurement and instrumentation needs: Why would you ever want to wrap a build tool? […]

Verifying Windows binaries, without Windows

TL;DR: We’ve open-sourced a new library, μthenticode, for verifying Authenticode signatures on Windows PE binaries without a Windows machine. We’ve also integrated it into recent builds of Winchecksec, so that you can use it today to verify signatures on your Windows executables! As a library, μthenticode aims to be a breeze to integrate: It’s written […]