Hiya, On 28/07/2019 19:07, Dmitry Belyavsky wrote: > Dear Stephen, > > I published a draft describing "Fake SNI" designed for the same purpose. It > allows (at least in theory) to cheat those who blocks all the handshakes > containing ESNI.
Yes, I recall that. The question below was only really about draft-ietf-tls-esni-04 though. Cheers, S. > > вс, 28 июля 2019 г., 15:25 Stephen Farrell <stephen.farr...@cs.tcd.ie>: > >> >> Hiya, >> >> ESNI drafts -03 and -04 envisage that the ESNIKeyublic_name >> and the TLS h/s cleartext SNI are the same. I'd expect that >> they mostly will be. >> >> But they don't have to be. A client could provide a way to >> use a client-chosen cleartext SNI when using ESNI to encrypt >> the real SNI. >> >> For example, my openssl build allows this for s_client. I've >> a colleague who's got a first build of curl using that that >> also allows such a local over-ride. I think other command-line >> clients might be likely to also support that kind of thing, if >> for no other reason than the existence of the draft-02 version >> that's deployed and has no public_name. But I guess being able >> to do a local over-ride may also be generally useful, while >> not being so useful for web browsers. For example, if a given >> public_name value is being censored, clients might at that >> point want to use something else. >> >> On the server side, my code also make no checks that the >> cleartext SNI used was the same as the public_name. And I >> don't think that causes any problems, so maybe ought be >> allowed too. >> >> I don't think allowing this (if the WG decide to) requires >> any major change to the spec, but there are a couple of >> language changes needed in section 5.1.3 and I guess we >> should add a sentence to the effect that using the public_name >> value from ESNIKeys in the cleartext SNI is recommended >> if you've no other value but is not required. >> >> Cheers, >> S. >> _______________________________________________ >> TLS mailing list >> TLS@ietf.org >> https://www.ietf.org/mailman/listinfo/tls >> >
0x5AB2FAF17B172BEA.asc
Description: application/pgp-keys
signature.asc
Description: OpenPGP digital signature
_______________________________________________ TLS mailing list TLS@ietf.org https://www.ietf.org/mailman/listinfo/tls
