Re: [TLS] PR#1091: Changes to provide middlebox robustness

The obvious problem with randomly adding fake versions is you have to have
a way of ensuring they won't conflict with *real* future versions - and
whatever pattern you decide upon in order to do that, middleboxes will use
that pattern to filter out fake versions, and fail as soon as you present
one with a real future version (i.e. TLS 1.4).

Can I also suggest adding a section about expected middlebox behaviour to
TLS 1.3? That way there is a reasonable chance that TLS 1.4 won't face the
same issues.
(Or can I do that myself? I'm not really familiar with the process, sorry)

On Sat, Nov 25, 2017 at 8:21 AM, Yuhong Bao <yuhongbao_386@hotmail.com>
wrote:

> That only applies to the ClientHello.
>
> ________________________________________
> From: Andrei Popov <Andrei.Popov@microsoft.com>
> Sent: Wednesday, November 22, 2017 11:22:23 AM
> To: Yuhong Bao; Peter Saint-Andre; Eric Rescorla
> Cc: tls@ietf.org; Tapio Sokura
> Subject: RE: [TLS] PR#1091: Changes to provide middlebox robustness
>
> The idea was for the client to randomly add non-existent TLS versions to
> supported_versions.
> Presumably, this will exercise the extensibility joint and prevent it from
> becoming unusable.
>
> I'm not convinced this new approach will help, but we know the old one
> required fallbacks every time a new protocol version was introduced.
>
> Cheers,
>
> Andrei
>
> -----Original Message-----
> From: TLS [mailto:tls-bounces@ietf.org] On Behalf Of Yuhong Bao
> Sent: Wednesday, November 22, 2017 11:04 AM
> To: Peter Saint-Andre <stpeter@stpeter.im>; Eric Rescorla <ekr@rtfm.com>
> Cc: tls@ietf.org; Tapio Sokura <tapio.sokura@iki.fi>
> Subject: Re: [TLS] PR#1091: Changes to provide middlebox robustness
>
> They are basically doing a supported_versions extension with only one
> entry in the ServerHello.
> The problem with future middleboxes should be obvious.
>
> ________________________________________
> From: Peter Saint-Andre <stpeter@stpeter.im>
> Sent: Wednesday, November 22, 2017 11:02:39 AM
> To: Yuhong Bao; Eric Rescorla
> Cc: tls@ietf.org; Tapio Sokura
> Subject: Re: [TLS] PR#1091: Changes to provide middlebox robustness
>
> On 11/22/17 11:16 AM, Yuhong Bao wrote:
> > The problem is not TLS 1.3, the problem is future versions of TLS.
>
> Would you mind explaining that in more detail?
>
> Peter
>
> _______________________________________________
> TLS mailing list
> TLS@ietf.org
> https://na01.safelinks.protection.outlook.com/?url=
> https%3A%2F%2Fwww.ietf.org%2Fmailman%2Flistinfo%2Ftls&
> data=02%7C01%7CAndrei.Popov%40microsoft.com%7C71d594d28d4241b8757f08d531db
> dbb2%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%
> 7C636469742719473989&sdata=fCAZVB8XHK3IJQAoSf%
> 2FUwSDlHYiy2tm0WBktCGS%2BPW8%3D&reserved=0
>
> _______________________________________________
> TLS mailing list
> TLS@ietf.org
> https://www.ietf.org/mailman/listinfo/tls
>