| name | artifact-provenance-verification |
| description | Assess and establish build artifact provenance and integrity — SLSA provenance level, signing/attestation (Sigstore/cosign, in-toto), and verification at deploy/admission. Use when you need to prove an artifact (container image, package, binary) came from the expected source and build, untampered. |
Goal
A clear picture of an artifact's provenance maturity and a path to "only verified,
attested artifacts are deployed" — so a tampered or unknown-origin artifact can't
reach production.
Frame against SLSA
Map the build/artifact flow to a SLSA build level and identify the next gap:
- L1 — provenance exists (build is scripted, provenance generated).
- L2 — provenance is signed and from a hosted build service.
- L3 — build runs on hardened, isolated infrastructure; provenance is
non-forgeable. This is the meaningful bar for tamper resistance.
Steps
- Inventory trust signals — is the artifact signed? By what identity
(keyless/OIDC via Sigstore, or a managed key)? Is there a provenance attestation
(in-toto / SLSA) linking artifact ↔ source commit ↔ builder?
- Verify the chain — source → build → artifact → registry → deploy. Confirm the
signing identity and provenance are checked, not just present.
- Find the enforcement gap — is verification required at admission/deploy
(e.g., cosign verify in an admission controller / policy gate), or merely
available? Unverified-but-signed is theater.
- Recommend — signing in CI (keyless preferred), provenance generation,
verification policy at the gate, and key/identity trust roots + revocation.
Output
A provenance assessment: current SLSA level · signing/attestation state · where
verification is (and isn't) enforced · prioritized steps to the next level. Pair with
pipeline-integrity-review for the build side and security-diagramming for the
chain-of-custody diagram.
Notes
Signing without enforced verification buys nothing — the control is the gate that
rejects unverified artifacts. Keyless (OIDC/Fulcio) signing avoids long-lived key
management and is the modern default. Provenance must bind artifact → exact source
commit → builder, or it can't prove "this came from that build."
