This adds a new mechanism for worker authentication that uses the
third-party arbitration of the original KMS flow by leveraging
recently-added capabilities in nodeenrollment to support a registration
wrapper. This allows for workers to be registered to the system with
just a name and a matching wrapper, while at the same time allowing
these workers to be used for private Vault access and multi-hop as they
contain per-worker encryption keys and support rotation.
Nodes using this mode will generate and rotate credentials in-memory
(using another recently added nodeenrollment capability) so will have a
new set of keys on every startup. This has the side effect of ensuring
that there is never a conflict or re-use of these credentials.
Note that the normal test worker flow was using the now-deprecated KMS
method; there is still a test that uses this (explicitly) but all other
tests using test workers that did not specify a specific PKI flow now
actually use this mechanism. This means there is fairly decent test
coverage in a general sense, plus the specific tests updated/added for
this feature.
This also adds a new KMS type that can be used to have
distinct KMSes for upstream authentication vs. accepting from
downstream.
When possible downstream workers will include their worker id information in
the connections they establish with the upstream using the nodeenrollment
library. The tracking listener now tracks connections that are connected in
this same way instead of just connections of type *tls.Conn.
Jeff Mitchell
Todd