shankar0123 cb308bb4c7 ci(release): migrate cosign sign-blob to --bundle (cosign v3.0) ...

Cosign v3.0 (shipped by default with sigstore/cosign-installer@cad07c2e,
release v3.0.5) removed --output-signature and --output-certificate from
the sign-blob subcommand. The replacement is a single --bundle flag that
emits a unified Sigstore bundle (.sigstore.json) containing the
signature, certificate chain, and Rekor inclusion proof in one file.

This change migrates both sign-blob invocations in .github/workflows/
release.yml (per-binary matrix signing and aggregate checksums.txt
signing), updates the artefact upload paths, the artefact aggregation
case filter, the GitHub Release asset list, and the release-notes body
verify-blob example. The README cosign verification snippet and sidecar
description are also updated to the --bundle / .sigstore.json shape.

No cosign version pinning. No legacy fallback. OCI image signing
(cosign sign on image digest) is unchanged — only sign-blob flags
changed in v3.0. See M-11 in certctl-audit-report.md.

Verification gates:
- YAML parse: OK
- go vet ./...: exit 0
- go build ./...: exit 0
- grep 'cosign sign-blob' release.yml: 2 (expected: 2)
- grep '.sigstore.json' release.yml: 9 (expected: >=5)
- grep '.sig/.pem' release.yml non-comment: 0 (expected: 0)
- README legacy cosign refs: 0 (expected: 0)
- docs/ legacy cosign refs: 0 (expected: 0)

Coverage: unchanged (CI workflow edit + README — zero Go code touched).

2026-04-18 09:29:20 +00:00

..

workflows

ci(release): migrate cosign sign-blob to --bundle (cosign v3.0)

2026-04-18 09:29:20 +00:00