Returns the derived keys for the most recent (newest) token
that has not "really expired".
This is used as a fallback when the tokenId from the original
request has expired: as per OPC UA Part 6 §6.7.3, the server
should use the current active token to secure outgoing messages.
Returns the derived keys for the most recent (newest) token that has not "really expired".
This is used as a fallback when the tokenId from the original request has expired: as per OPC UA Part 6 §6.7.3, the server should use the current active token to secure outgoing messages.