Stateless Reset and CID Recovery

[MikeBishop]

6.13.4.2 discusses the need to request a non-zero-length CID if you want to be able to generate Stateless Resets:

An endpoint that loses state can use the same method to generate a valid Stateless Reset Token. The connection ID comes from the packet that the endpoint receives.

This design relies on the peer always sending a connection ID in its packets so that the endpoint can use the connection ID from a packet to reset the connection. An endpoint that uses this design cannot allow its peers to send packets with a zero-length destination connection ID.

However, it doesn't discuss the fact that the length of the CID isn't identifiable from a short-header packet, and therefore even this algorithm works only if you either use a constant CID length or embed a length indicator in your CIDs. This might be a worthwhile piece to mention.