README
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Generation of SLSA3+ provenance for native GitHub projects
This repository contains tools for generating non-forgeable SLSA provenance on GitHub that meets the build and provenance requirements for SLSA level 3 and above.
Use of the provided GitHub Actions reusable workflows only is not sufficient to meet all of the requirements at SLSA level 3. Specifically, the source requirements are not covered by these workflows and must be handled explicitly to meet all requirements at SLSA level 3+.
This repository contains the code, examples and technical design for system described in the blog post on Non forgeable SLSA provenance using GitHub workflows.
Generation of provenance
Below we describe the various builders and generators in this repository. They let you build and / or generate non-forgeable provenance using a trusted / isolated re-usable workflow. You can read up on the design in our technical design document.
Note: At present the GitHub Actions provided in this repository as builders and generators MUST be referenced by
a tag that correpsonds to a semantic version of the form @vX.Y.Z. The build will fail
if you reference it via a shorter tag like @vX.Y or @vX or if you reference it by a tag of a different form (e.g., @main).
Builders
Builders build and generate provenance. They let you meet the build and provenance requirements for SLSA Level 3 and above.
Builders are able to report the commands used to generate your artifact in the provenance.
This repository hosts the following builders:
- Go Builder SLSA Level 3. Status: available. This builder builds and generates provenance for your Go projects. To use it, follow the Go builder's README.md.
- Container Builder SLSA Level 3. Status: WIP, expected release in Sept 2022. This builder will build your container image and generate provenance. The generated provenance will be compatible with cosign's attestation format.
- Dockerfile-based Builder SLSA Level 3. Status: WIP, see #23. This builder will build arbitrary artifacts using building steps defined in a Dockerfile.
If you would rather build your project yourself, use the generators instead as explained in the next section.
Provenance-only generators
Provenance-only generators let you build your artifact, and only generate provenance for you. They let you meet the provenance requirements for SLSA Level 3.
Generators create an attestation to a software artifact coming from your repository.
Generators are not able to report the commands used to generate your artifact in the provenance.
This repository hosts the following generators:
- Generic generator SLSA Level 3. Status: WIP, expected release July 2022. This generator generates provenance for arbitrary artifacts of your choice. To use it, follow the Generic generator's README.md.
- Container generator SLSA Level 3. Status: WIP, expected release Aug-Sept 2022, see #409. This generator will generate provenance for container images. The generated provenance will be compatible with cosign's attestation format.
Verification of provenance
To verify the provenance, use the github.com/slsa-framework/slsa-verifier project.
Note: At present the GitHub Actions provided in this repository as builders and generators MUST be referenced by tag in order for the slsa-verifier to be able to verify the ref of the trusted builder/generator's reusable workflow.
This is contrary to the best practice which recommends referencing by digest, but intentional due to limits in GitHub Actions. The desire to be able to verify reusable workflows pinned by hash, and the reasons for the current status, are tracked as Issue #12 in the slsa-verifier project.
Installation
To install the verifier, see slsa-framework/slsa-verifier#installation.
Inputs
The inputs of the verifier are described in slsa-framework/slsa-verifier#available-options.
Command line examples
A command line example is provided in slsa-framework/slsa-verifier#example.
Technical design
Blog post
Find our blog post series here.
Specifications
For a more in-depth technical dive, read the SPECIFICATIONS.md.
Provenance format
The format of the provenance is available in PROVENANCE_FORMAT.md.
Directories