* Move the server daemons into their own package
With this change the internal/server package now is dedicated to the server domain (workers and controllers) and not to the server daemons.
The hope is that this will make it easier to keep the daemons decoupled from the representation of the servers in the database.
This change introduces a `nonceFn` field that can be changed
by a test but at runtime is transparent to the code that calls it.
The current nonce-generating logic defaults to a test-only field which
opens us up to this value inadvertently being set.
With this change, the default behavior becomes using `base62` to
generate a random nonce, and any tests have to explicitly change that.
This stores worker connection nonces within the database to ensure
uniqueness of connections. Prior the connection required any attacker to
be able to decrypt the incoming encrypted authentication message in
order to replay (and if the attacker has access to the KMS you have
bigger problems), but with this change even if an attacker does have
access to the KMS key, they cannot reuse the same message. (If they're
able to encrypt against the KMS key, they can still act as a worker with
a new message, so this only really helps if they only have decryption
capabilities.)
Todd
Haotian
Hugo Vieira
Jeff Mitchell