DTLS 1.3 Process App Data sent from the Server if it arrives before the Servers ACK

[rsith71]

There is a scenario when the server sends APP data right away since this is UDP it can arrive before the ACK message. Right now we just drop the app data. This is acceptable by the RFC but we would prefer to read this data before the ACK message.

A new test should be added to dtlstest where the ACK message sent by the server is dropped and we should verify that the client resends the Finish message.

TODO is in statem_clnt.c:

[fwh-dc]

Hmm logically I would count the app data as an “ack”. The RFC mentions something with records from newer epochs counts as ack. But that might only be for handshake messages?
I’m wondering if this is something missing in the rfc? I know there is a bis document to the standard. Perhaps if this is missing it should be added there?