This enables chain of trust verification for signing scriptworkers.
chain of trust
As I mentioned before, scriptworkers allow for more control and auditability around sensitive release-oriented tasks in Taskcluster. The Chain of Trust allows us to trace requests back to the tree and verify each previous task in the chain.
We have been generating Chain of Trust artifacts for a while now. These are gpg-signed json blobs with the task definition, artifact shas, and other information needed to verify the task and follow the chain back to the tree. However, nothing has been verifying these artifacts until now.
With the latest scriptworker changes, scriptworker follows and verifies the chain of trust before proceeding with its task. If there is any discrepancy in the verification step, it marks the task invalid before proceeding further. This is effectively a second factor to verify task request authenticity.
This is running on signing scriptworkers which sign nightlies on date-branch. We still need to support and update the other scriptworker instance types to enable end-to-end chain of trust verification.