Extend the built-in policy to validate signed moby/buildkit release and
floating tags before docker-container builders are created.
Pull the image first, inspect it through Docker, and bind verification to the
descriptor digest. Resolve signature attestations through the BuildKit API
embedded in the Docker daemon.
If pulling fails, use a local image while applying the same verification when
the containerd image store exposes an immutable descriptor. Keep the classic
image-store behavior unchanged because no descriptor is available.
Allow unmanaged repositories and digest-only references unchanged. Add the
allow-untrusted-image driver option as an explicit verification bypass.
Document the behavior and add policy, digest-pinning, and local fallback
coverage.
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Extends the builtin default policy to verify docker-github-builder
signatures on docker/buildkit-syft-scanner images. Tags `latest` and
1.10+ require a signature from the docker/buildkit-syft-scanner source
repository; older tags pass through unchanged. Factors the shared ref
matching logic into sig_ref_matches for dockerfile and introduces a
syft-scanner variant that uses the plain refs/tags/ prefix.
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Embed an opt-in default source policy for Docker-managed frontend images.
Load it ahead of user policies when enabled, and cover behavior with table-
driven policy tests for signed, unsigned, floating, and labs tags.
Makes sure if there is any attack against the docker/dockerfile
releases, or they accidentally point to worng images, these are automatically detected.
In a future release these should become opt-out.
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Tonis Tiigi