cosign VS notation

Cosign: In this context, Cosign from the Sigstore project offers a compelling solution. Its simplicity, registry compatibility, and effective link between images and their signatures provide a user-friendly and versatile approach. The integration of Fulcio for certificate management and Rekor for secure logging enhances Cosign's appeal, making it particularly suitable for modern development environments that prioritize security and agility.

sigstore is another suite of tools that focuses on attestation and provenance. Within the suite are two tools I heard mentioned a few times at KubeCon: Cosign and Rekor.

Since we can distribute Spin applications using popular registry services, we can also take advantage of ecosystem tools such as Sigstore and Cosign, which address the software supply chain issue by signing and verifying applications using Sigstore's new keyless signatures (using OIDC identity tokens from providers such as GitHub).

Use distroless images (which contain only application and its runtime dependencies, and don't include package managers/shells or any other programs you would expect to find in a standard Linux distribution). All distroless images are signed by cosign.

$ COSIGN_EXPERIMENTAL=1 cosign verify-blob --cert https://github.com/sigstore/cosign/releases/download/v1.13.1/cosign-linux-amd64-keyless.pem --signature https://github.com/sigstore/cosign/releases/download/v1.13.1/cosign-linux-amd64-keyless.sig https://github.com/sigstore/cosign/releases/download/v1.13.1/cosign-linux-amd64

Another thing to look for is, whether the image is signed using something like cosign (https://github.com/sigstore/cosign). This lets the publisher digitally sign the image, so you at least know that what's on the registry is what they intended to put there. Handy to avoid the risks of attackers squatting similar names and catching typos.

name: Docker # This workflow uses actions that are not certified by GitHub. # They are provided by a third-party and are governed by # separate terms of service, privacy policy, and support # documentation. on: push: branches: [ "main" ] # Publish semver tags as releases. tags: [ 'v*.*.*' ] pull_request: branches: [ "main" ] paths: - src/MamisSolidarias.WebAPI.Campaigns/Dockerfile - .github/workflows/docker-publish.yml workflow_dispatch: env: # Use docker.io for Docker Hub if empty REGISTRY: ghcr.io IMAGE_NAME: mamis-solidarias/campaigns jobs: build: runs-on: ubuntu-latest permissions: contents: read packages: write # This is used to complete the identity challenge # with sigstore/fulcio when running outside of PRs. id-token: write steps: - name: Checkout repository uses: actions/checkout@v3 # Install the cosign tool except on PR # https://github.com/sigstore/cosign-installer - name: Install cosign if: github.event_name != 'pull_request' uses: sigstore/cosign-installer@main with: cosign-release: 'v1.13.1' - name: Set up QEMU uses: docker/setup-qemu-action@v2 with: platforms: 'arm64' # Workaround: https://github.com/docker/build-push-action/issues/461 - name: Setup Docker buildx uses: docker/setup-buildx-action@v2 # Login against a Docker registry except on PR # https://github.com/docker/login-action - name: Log into registry ${{ env.REGISTRY }} if: github.event_name != 'pull_request' uses: docker/login-action@v2 with: registry: ${{ env.REGISTRY }} username: ${{ github.actor }} password: ${{ secrets.GITHUB_TOKEN }} # Extract metadata (tags, labels) for Docker # https://github.com/docker/metadata-action - name: Extract Docker metadata id: meta uses: docker/metadata-action@v4 with: images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }} tags: | type=schedule type=ref,event=branch type=ref,event=pr type=semver,pattern={{version}} type=semver,pattern={{major}}.{{minor}} type=semver,pattern={{major}} type=sha # Build and push Docker image with Buildx (don't push on PR) # https://github.com/docker/build-push-action - name: Build and push Docker image id: build-and-push uses: docker/build-push-action@v3 with: context: . platforms: linux/amd64, linux/arm64 file: src/MamisSolidarias.WebAPI.Campaigns/Dockerfile push: ${{ github.event_name != 'pull_request' }} tags: ${{ steps.meta.outputs.tags }} labels: ${{ steps.meta.outputs.labels }} # Sign the resulting Docker image digest except on PRs. # This will only write to the public Rekor transparency log when the Docker # repository is public to avoid leaking data. If you would like to publish # transparency data even for private images, pass --force to cosign below. # https://github.com/sigstore/cosign - name: Sign the published Docker image if: ${{ github.event_name != 'pull_request' }} env: COSIGN_EXPERIMENTAL: "true" # This step uses the identity token to provision an ephemeral certificate # against the sigstore community Fulcio instance. run: echo "${{ steps.meta.outputs.tags }}" | xargs -I {} cosign sign {}@${{ steps.build-and-push.outputs.digest }}

After inspecting the layers i think you should start thinking about signing your images: https://github.com/sigstore/cosign/

cosign

Notary v2: The evolution to Notary v2 brought improvements in signature portability and integration with third-party key management solutions. However, it does not provide a certificate authority, leaving public key discovery for open-source image verification as an unresolved issue.

Notation

Notation is another command-line too that lets you digitally sign artifacts. And those signatures essentaily become the stamps of approval for the different things in your software supply chain. For example, container images.

Notary is the CNCF project name and is often referenced when referring to the process of signing digital artifacts, but Notation is the command line tool that does the heavy lifting. Run the following commands to install Notation.

It should be interoperable, that's the goal. I proposed some idea for nv2 here: https://github.com/notaryproject/nv2/issues/39 and here: https://github.com/notaryproject/nv2/issues/40 too.