Open Source Summit North America 2023

Software supply chain attacks have seen a 742% increase in the last three years. in-toto is a battle-tested and broadly deployed CNCF incubated project that counters these threats. The framework connects security efforts such as SLSA, Sigstore, and SBOMs, where signed and verifiable in-toto attestations are used to express claims about software supply chain steps and artifacts. However, trusting attestations and their policies is predicated on bootstrapping their verification keys and securely distributing them to end users. Enter TUF! The Update Framework (TUF) is a widely adopted CNCF graduated project used to secure software repositories. TUF protects against a range of subtle attacks on software distribution, and is designed to be secure even when some components of the system are compromised. TUF can be used to unambiguously associate artifacts with their in-toto metadata, thereby bootstrapping trust for attestations. Thus, combining in-toto and TUF provides a secure way to verify end-to-end software supply chain integrity. This talk covers the fundamentals of both in-toto and TUF, discusses how to combine them with a real world case study where the two have been used together for years, and presents new open source tooling that simplifies deploying the two systems together.