GitHub takes aim at software supply chain security

GitHub has introduced Artifact Attestations, a software signing and verification feature based on Sigstore that protects the integrity of software builds in GitHub Actions workflows. Artifiact Attestations is now available in a public beta.

Announced May 2, Artifact Attestations allows project maintainers to create a “tamper-proof, unforgeable paper trail” that links software artifacts to the process that created them. “Downstream consumers of this metadata can use it as a foundation for new security and validity checks through policy evaluations via tools like Rego and Cue,” GitHub wrote in the announcement.

Verification support initially will be based on GitHub CLI, but this will be expanded to bring the same controls to the Kubernetes ecosystem later this year. Powering Artifact Attestations is the Sigstore open-source project for signing and verifying software artifacts.

Artifact Attestations helps reduce the complexity of deploying public key infrastructure by placing trust in the security of a GitHub account, GitHub said. This is done via signing a document with a temporary key pair. A public key is attached to a certificate associated with a build system’s workload identity. The private key does not leave process memory and is discarded immediately after signing. This differs from other approaches to signing that rely on human identities and long-lived keys, GitHub said.

Setting up Artifact Attestations is done by adding YAML to a GitHub Actions workflow to create an attestation and installing the GitHub CLI tool to verify it.