On Thu, Jan 7, 2021 at 3:18 PM Benjamin Kaduk <[email protected]> wrote: > Thanks everyone for the productive discussion. It's clear that there's > a lot of background available to those who participated in the previous > WG discussions but (understandably!) did not make it into the document > itself, and I appreciate the effort that was put in to help share that with > me. > > Just to state it clearly, at no point has my position been that QUIC v1 > needs to be delayed until a complete version negotiation story exists. > As this was a "discuss discuss", my goal was to obtain more information > about the actual situation in order to confirm that there are no > significant issues, since my interpretation of the text in the document > itself left that possibility open. > > Attempting to summarize salient points: > > - the IETF is only currently defining bindings for HTTP over QUIC, > though other entities are free to define their own protocol over QUIC > at any time. > - the only way currently defined to discover a QUIC endpoint to use as > server for a given HTTP service is the Alt-Svc header field, which > uses an ALPN value to indicate the protocol to use; it is perhaps not > fully nailed down that the ALPN value will be specific to a particular > version of QUIC but the ALPN vlaue probably will be specific to a > particular version of QUIC. >
I don't believe this is correct. You can simply try to connect with QUICv1. > - A downgrade protection mechanism solely in-band at the QUIC layer will > not be a complete solution for existing protocols that may also fall > back to a TCP binding (or new protocols that need to traverse networks > like the Internet that don't reliably pass UDP in the ways QUIC > needs). New protocols over QUIC that are berift of such legacy would > have a complete solution, though. > Hmm.... Well, it obviously can't be at the QUIC layer, because you won't be using QUIC at all, but it can be at the TLS layer. - In particular, we do *not* expect non-IETF QUIC versions to define > their own downgrade protection scheme. They are expected to either > pick up the IETF one (when it exists) or just only use a single > version at a time, possibly with out of band configuration. > Maybe? I'm not sure there is a consensus one way or the other on this. -Ekr
