Supporting 0-RTT means that the server has to support 1.3. We should reject a 1.2 ServerHello if the client was doing 0-RTT. See also https://github.com/tlswg/tls13-spec/pull/502
Summary: Client should reject TLS 1.3 if they are doing 0-RTT → Client should reject TLS 1.2 if they are doing 0-RTT
You need to log in before you can comment on or make changes to this bug.