Re: Questions about Version Negotiation Concerning Possible Handshake Interruption

[Christian Huitema <[e-mail]>]

On 2/9/2018 3:06 PM, Lingmo Zhu wrote:
>
> IMHO we can see that such interference is pretty easy to be used and
> it could leading to aborted QUIC connection and probably a fallback to
> any old approach for higher level protocol. Even virus targeting home
> routers could do that, without gov involved. For what outcome, I think
> it's pretty simple: forcing higher level protocol fallback to other
> transport protocol. Since QUIC has been designed much more secure than
> older protocols, it could be hard to do some eavesdropping or
> hijacking. But if fallback happens, it would be another story.
> Considering DNS over QUIC, a virus-infected home router could
> interfere with QUIC handshake cause fallback to TLS, then RST may
> cause fallback to clear text, which is easy to be hijacked and leads
> client to some phishing site.
>

In theory, it should be possible to protect against "man on the side"
attacks. Do some kind of speculative execution on the first packet that
you receive, but also keep the context available for some time in case a
"better" packet comes later. With that approach, the attacker could not
just inject a "packet of death"; they will also need to suppress the
correct response from the actual server. That's an interesting idea.
Have you tried some experiments?

-- Christian Huitema