Generate signed SBOM attestations for workflow artifacts. Internally powered by the @actions/attest package.
Attestations bind some subject (a named artifact along with its digest) to a a Software Bill of Materials (SBOM) using the in-toto format. The action accepts SBOMs which have been generated by external tools. Provided SBOMs must be in either the SPDX or CycloneDX JSON-serialized format.
A verifiable signature is generated for the attestation using a short-lived Sigstore-issued signing certificate. If the repository initiating the GitHub Actions workflow is public, the public-good instance of Sigstore will be used to generate the attestation signature. If the repository is private/internal, it will use the GitHub private Sigstore instance.
Once the attestation has been created and signed, it will be uploaded to the GH attestations API and associated with the repository from which the workflow was initiated.
Attestations can be verified using the attestation command in the GitHub
CLI.
See Using artifact attestations to establish provenance for builds for more information on artifact attestations.
Within the GitHub Actions workflow which builds some artifact you would like to attest:
-
Ensure that the following permissions are set:
permissions: id-token: write attestations: write
The
id-tokenpermission gives the action the ability to mint the OIDC token necessary to request a Sigstore signing certificate. Theattestationspermission is necessary to persist the attestation. -
Add the following to your workflow after your artifact has been built and your SBOM has been generated:
- uses: actions/attest-sbom@v1 with: subject-path: '<PATH TO ARTIFACT>' sbom-path: '<PATH TO SBOM>'
The
subject-pathparameter should identify the artifact for which you want to generate an SBOM attestation. Thesbom-pathparameter should identify the SBOM document to be associated with the subject.
See action.yml
- uses: actions/attest-sbom@v1
with:
# Path to the artifact serving as the subject of the attestation. Must
# specify exactly one of "subject-path" or "subject-digest".
subject-path:
# SHA256 digest of the subject for the attestation. Must be in the form
# "sha256:hex_digest" (e.g. "sha256:abc123..."). Must specify exactly one
# of "subject-path" or "subject-digest".
subject-digest:
# Subject name as it should appear in the attestation. Required unless
# "subject-path" is specified, in which case it will be inferred from the
# path.
subject-name:
# Path to the JSON-formatted SBOM file to attest. When specified, the
# "scan-path" and "sbom-format" inputs are ignored.
sbom-path:
# Whether to push the attestation to the image registry. Requires that the
# "subject-name" parameter specify the fully-qualified image name and that
# the "subject-digest" parameter be specified. Defaults to false.
push-to-registry:
# The GitHub token used to make authenticated API requests. Default is
# ${{ github.token }}
github-token:| Name | Description | Example |
|---|---|---|
bundle-path |
Absolute path to the file containing the generated attestation | /tmp/attestaion.jsonl |
Attestations are saved in the JSON-serialized Sigstore bundle format.
If multiple subjects are being attested at the same time, each attestation will be written to the output file on a separate line (using the JSON Lines format).
For the basic use case, simply add the attest-sbom action to your workflow and
supply the path to the artifact and SBOM for which you want to generate
attestation.
name: build-attest
on:
workflow_dispatch:
jobs:
build:
permissions:
id-token: write
contents: read
attestations: write
steps:
- name: Checkout
uses: actions/checkout@v4
- name: Build artifact
run: make my-app
- name: Generate SBOM
uses: anchore/sbom-action@v0
with:
format: 'spdx-json'
output-file: 'sbom.spdx.json'
- name: Attest
uses: actions/attest-sbom@v1
with:
subject-path: '${{ github.workspace }}/my-app'
sbom-path: 'sbom.spdx.json'If you are generating multiple artifacts, you can generate an attestation for
each by using a wildcard in the subject-path input.
- uses: actions/attest-sbom@v1
with:
subject-path: 'dist/**/my-bin-*'
sbom-path: '${{ github.workspace }}/my-bin.sbom.spdx.json'For supported wildcards along with behavior and documentation, see @actions/glob which is used internally to search for files.
When working with container images you can invoke the action with the
subject-name and subject-digest inputs.
If you want to publish the attestation to the container registry with the
push-to-registry option, it is important that the subject-name specify the
fully-qualified image name (e.g. "ghcr.io/user/app" or
"acme.azurecr.io/user/app"). Do NOT include a tag as part of the image name --
the specific image being attested is identified by the supplied digest.
NOTE: When pushing to Docker Hub, please use "index.docker.io" as the registry portion of the image name.
name: build-attested-image
on:
push:
branches: [main]
jobs:
build:
runs-on: ubuntu-latest
permissions:
id-token: write
packages: write
contents: read
attestations: write
env:
REGISTRY: ghcr.io
IMAGE_NAME: ${{ github.repository }}
steps:
- name: Checkout
uses: actions/checkout@v4
- name: Login to GitHub Container Registry
uses: docker/login-action@v3
with:
registry: ${{ env.REGISTRY }}
username: ${{ github.actor }}
password: ${{ secrets.GITHUB_TOKEN }}
- name: Build and push image
id: push
uses: docker/build-push-action@v5.0.0
with:
context: .
push: true
tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
- name: Generate SBOM
uses: anchore/sbom-action@v0
with:
image: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
format: 'cyclonedx-json'
output-file: 'sbom.cyclonedx.json'
- name: Attest
uses: actions/attest-sbom@v1
id: attest
with:
subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
subject-digest: ${{ steps.push.outputs.digest }}
sbom-path: 'sbom.cyclonedx.json'
push-to-registry: true