Pin actions to a full length commit SHA

[naveensrinivasan]

• Pinned actions by SHA https://github.com/ossf/scorecard/blob/main/docs/checks.md#pinned-dependencies

Pin actions to a full length commit SHA

Pinning an action to a full length commit SHA is currently the only way to use an action as an immutable release. Pinning to a particular SHA helps mitigate the risk of a bad actor adding a backdoor to the action's repository, as they would need to generate a SHA-1 collision for a valid Git object payload.

https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-third-party-actions

How do I validate these pinned actions?

Also, dependabot supports upgrading based on SHA. ossf/scorecard#1700

GitHub's own repository pin's their checkout actions by SHA and doesn't use the version tag
https://github.com/github/docs/blob/ea7f218c91ecbae9a700a8702b51a7d2736e0d2c/.github/workflows/docs-review-collect.yml#L23

Signed-off-by: naveensrinivasan [email protected]

[diemol]

You mention that

Also, dependabot supports upgrading based on SHA. ossf/scorecard#1700

But how will I know which tag am I using? Seems the comments in those workflows were added manually. Readability is important for us and we check the actions before adding them to our workflows.

[naveensrinivasan]

You mention that

Also, dependabot supports upgrading based on SHA. ossf/scorecard#1700

But how will I know which tag am I using? Seems the comments in those workflows were added manually. Readability is important for us and we check the actions before adding them to our workflows.

I understand that is an issue. There isn't a straight way out now TBH. There needs to be some grep and awk of the file to parse the SHA and use something like this to relate the SHA to a tag.
https://gist.github.com/naveensrinivasan/ca008c07279176acce28969fb77d056f

The goal is to avoid something like this https://julienrenaux.fr/2019/12/20/github-actions-security-risk/

[diemol]

OK, let's give it a try. If it becomes hard to maintain or dependabot does not help, we will probably revert.