Verifying a Release

All four are attached to every GitHub Release as assets, from v0.2.503 forward. Releases v0.2.500 through v0.2.502 carry the SBOM bundle only: the unified manifest landed in v0.2.503 and is forward-only (re-tagging earlier releases would break consumer pins on existing SHAs).

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TL;DR — verify v0.2.503+ end-to-end

# 0. Pick the release to verify
TAG=v0.2.503
REPO=sebastienrousseau/dotfiles

# 1. Download every attestation artefact
gh release download "$TAG" --repo "$REPO" \
  --pattern dotfiles-sbom.spdx.json \
  --pattern dotfiles-sbom.spdx.json.sig \
  --pattern dotfiles-sbom.spdx.json.pem \
  --pattern dotfiles-sbom.spdx.json.intoto.jsonl \
  --pattern ALL_SHA256SUMS \
  --pattern ALL_SHA256SUMS.sig \
  --pattern ALL_SHA256SUMS.pem

# 2. Verify Cosign signature on the SBOM (binds SBOM to CI workflow identity)
cosign verify-blob \
  --certificate dotfiles-sbom.spdx.json.pem \
  --signature  dotfiles-sbom.spdx.json.sig \
  --certificate-identity-regexp "^https://github.com/$REPO/" \
  --certificate-oidc-issuer https://token.actions.githubusercontent.com \
  dotfiles-sbom.spdx.json

# 3. Verify SLSA provenance (binds SBOM to exact source tag + builder)
slsa-verifier verify-artifact dotfiles-sbom.spdx.json \
  --provenance-path dotfiles-sbom.spdx.json.intoto.jsonl \
  --source-uri "github.com/$REPO" \
  --source-tag "$TAG"

# 4. Verify the unified manifest, then verify every other asset against it.
#    One signed file covers all release artefacts in one shot.
cosign verify-blob \
  --certificate ALL_SHA256SUMS.pem \
  --signature  ALL_SHA256SUMS.sig \
  --certificate-identity-regexp "^https://github.com/$REPO/" \
  --certificate-oidc-issuer https://token.actions.githubusercontent.com \
  ALL_SHA256SUMS

gh release download "$TAG" --repo "$REPO" --dir .  # pull every other asset
sha256sum -c ALL_SHA256SUMS                        # one line per asset

All four commands should print "Verified" / "PASSED" / "OK" and exit 0. If any fails, the release was tampered with: open an issue at https://github.com/sebastienrousseau/dotfiles/issues and do not install.

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Tool installation

If you don't have Go installed, fetch the pre-built slsa-verifier binary from https://github.com/slsa-framework/slsa-verifier/releases (SHA256-verify per their release notes).

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What each verification actually proves

cosign verify-blob succeeds

• The SBOM was signed by a workflow run on this repository (the --certificate-identity-regexp enforces it).
• The signing OIDC token was issued by GitHub Actions (the --certificate-oidc-issuer enforces it).
• The signature is recorded in the Rekor public transparency log (cosign queries this automatically) — anyone can audit it.
• The Cosign cert was issued by Fulcio (the sigstore CA) and was valid at the time of signing.

This does not prove what the build process did — only that "the file you have is the file CI produced." For "what did CI do", see SLSA verification below.

slsa-verifier verify-artifact succeeds

• The SBOM digest matches a provenance statement.
• The provenance was generated by the SLSA-Generator running on GitHub-hosted runners for this exact repository.
• The build was triggered by the named tag (--source-tag $TAG).
• The provenance is anchored in Rekor (immutable, third-party-auditable).

SLSA Level 3 is achieved because: (a) the provenance is generated by a trusted, isolated builder (slsa-github-generator), not by us; (b) the builder runs with hermetic, non-falsifiable inputs; (c) the provenance is signed by the builder's own identity, not ours.

What none of this proves

The framework's source code is not formally verified. SBOM + SLSA + Cosign protect the supply chain (you got what we shipped) — not the correctness (what we shipped does what we claim).

For correctness review:

• Code is open under MIT — read it. Start at bin/dot.
• CI runs ~75 checks per PR (shellcheck, shfmt, CodeQL, Semgrep, Codacy, etc.).
• Pre-commit hooks reject typos, unsigned commits, raw secrets.
• See docs/security/SCORECARD.md for the OpenSSF score posture.

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In-shell one-liner for ongoing verification

If you intend to install or update from a release tag, add this to your shell startup (already in dot_config/shell/* for users who run chezmoi apply):

verify-dot-release() {
  local tag="${1:-$(gh release view --json tagName --jq .tagName \
    --repo sebastienrousseau/dotfiles)}"
  local tmp
  tmp="$(mktemp -d)"
  ( cd "$tmp" \
    && gh release download "$tag" --repo sebastienrousseau/dotfiles \
      --pattern 'dotfiles-sbom.*' \
    && cosign verify-blob \
      --certificate dotfiles-sbom.spdx.json.pem \
      --signature  dotfiles-sbom.spdx.json.sig \
      --certificate-identity-regexp '^https://github.com/sebastienrousseau/dotfiles/' \
      --certificate-oidc-issuer https://token.actions.githubusercontent.com \
      dotfiles-sbom.spdx.json \
    && slsa-verifier verify-artifact dotfiles-sbom.spdx.json \
      --provenance-path dotfiles-sbom.spdx.json.intoto.jsonl \
      --source-uri github.com/sebastienrousseau/dotfiles \
      --source-tag "$tag"
  )
  local rc=$?
  rm -rf "$tmp"
  return $rc
}

Usage:

verify-dot-release             # verify latest
verify-dot-release v0.2.502    # verify specific tag

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If verification fails

1. Don't install. Stop the bootstrap script. ^C any in-flight chezmoi apply.
2. Compare assets. The release page shows file sizes — if yours don't match what's on https://github.com/sebastienrousseau/dotfiles/releases, you downloaded from a man-in-the-middle.
3. Report: open an issue and email [email protected] (encrypted to the WKD-published GPG key — fingerprint 55AFAD364FD9DB3819E61F0C8D688FAFA9144693). Acknowledgement SLA: 72 hours per SECURITY.md.

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See also

• SECURITY.md — coordinated disclosure policy.
• docs/security/KEY_ROTATION.md — disclosure-key rotation procedure.
• docs/security/SCORECARD.md — OpenSSF Scorecard posture.
• docs/operations/HARD_AUDIT_2026.md Part 7 — the GPG key generation + WKD publication record.
• Sigstore Cosign docs
• SLSA verifier docs