Re: [TLS] Alternative ESNI?

2018-12-19 Thread Kathleen Moriarty
Hey EKR, Sent from my mobile device > On Dec 18, 2018, at 4:48 PM, Eric Rescorla wrote: > > > >> On Tue, Dec 18, 2018 at 10:54 AM Kathleen Moriarty >> wrote: >> Just a clarifying question inline >>> On Sun, Dec 16, 2018 at 3:30 PM Eric Rescorla wrote: >>> >>> On Sun, Dec 16, 2018 at

Re: [TLS] Alternative ESNI?

2018-12-18 Thread Viktor Dukhovni
> On Dec 18, 2018, at 4:48 PM, Eric Rescorla wrote: > > To my knowledge, no generic browser client does DNSSEC validation, for the > reason that when people have looked at it it created unaceptable failure > rates. Agreed. That's a pretty safe bet. The last-mile problem is still with us f

Re: [TLS] Alternative ESNI?

2018-12-18 Thread Eric Rescorla
On Tue, Dec 18, 2018 at 10:54 AM Kathleen Moriarty < kathleen.moriarty.i...@gmail.com> wrote: > Just a clarifying question inline > On Sun, Dec 16, 2018 at 3:30 PM Eric Rescorla wrote: > >> >> >> On Sun, Dec 16, 2018 at 11:45 AM Paul Wouters wrote: >> >>> On Fri, 14 Dec 2018, Eric Rescorla wrote

Re: [TLS] Alternative ESNI?

2018-12-18 Thread Kathleen Moriarty
Just a clarifying question inline On Sun, Dec 16, 2018 at 3:30 PM Eric Rescorla wrote: > > > On Sun, Dec 16, 2018 at 11:45 AM Paul Wouters wrote: > >> On Fri, 14 Dec 2018, Eric Rescorla wrote: >> >> > However, in a large number of cases (e.g., an attacker on your local >> network, >> > there are

Re: [TLS] Alternative ESNI?

2018-12-18 Thread Nico Williams
On Fri, Dec 14, 2018 at 08:53:47PM -0600, Nico Williams wrote: > Figure 1: Alternative ESNI w/o active protection Figure 1 was expositional. Please forget it. > Figure 2: Alternative ESNI w/ active protection > Figure 3: Alternative ESNI w/ active protec

Re: [TLS] Alternative ESNI?

2018-12-17 Thread Nico Williams
On Tue, Dec 18, 2018 at 01:58:53AM +, Stephen Farrell wrote: > On 17/12/2018 23:33, Nico Williams wrote: > > Maybe we do both, the current ESNI proposal and this as an alternative > > for when ESNI keyshare orchestration is difficult, and in that case you > > don't get to do split mode. > > In

Re: [TLS] Alternative ESNI?

2018-12-17 Thread Viktor Dukhovni
> On Dec 17, 2018, at 8:58 PM, Stephen Farrell > wrote: > > That said, I'd bet we're all generally unkeen on "do both" but > maybe the above-mentioned PR avoids that by casting the HRR-mode > as way to better handle a likely operational failure mode. I guess the reason I started thinking along

Re: [TLS] Alternative ESNI?

2018-12-17 Thread Stephen Farrell
On 17/12/2018 23:33, Nico Williams wrote: > > Maybe we do both, the current ESNI proposal and this as an alternative > for when ESNI keyshare orchestration is difficult, and in that case you > don't get to do split mode. Interesting that the above overlaps a bit with the PR davidben just posted

Re: [TLS] Alternative ESNI?

2018-12-17 Thread Nico Williams
On Sat, Dec 15, 2018 at 01:08:50PM +, Stephen Farrell wrote: > On 15/12/2018 02:53, Nico Williams wrote: > > OpenSSL extracts and uses SNI from session resumption tickets. > > > > This gave Viktor Dukhovni and Matt Caswell an idea that I'll relay here > > on their behalf. > > I agree this is

Re: [TLS] Alternative ESNI?

2018-12-16 Thread Eric Rescorla
On Sun, Dec 16, 2018 at 11:45 AM Paul Wouters wrote: > On Fri, 14 Dec 2018, Eric Rescorla wrote: > > > However, in a large number of cases (e.g., an attacker on your local > network, > > there are non-DNSSEC ways of obtaining this property, such as using DoH. > > Data origin authenticity is not t

Re: [TLS] Alternative ESNI?

2018-12-16 Thread Paul Wouters
On Fri, 14 Dec 2018, Eric Rescorla wrote: However, in a large number of cases (e.g., an attacker on your local network, there are non-DNSSEC ways of obtaining this property, such as using DoH. Data origin authenticity is not the same as transport security. DoH offers no guarantee that the non

Re: [TLS] Alternative ESNI?

2018-12-15 Thread Eric Rescorla
On Sat, Dec 15, 2018 at 12:01 PM Viktor Dukhovni wrote: > > > > On Dec 15, 2018, at 8:08 AM, Stephen Farrell > wrote: > > > > I don't see any point in considering the variant with the easy > > active attack though; > > For the record the easy MiTM attack requires on-path TCP termination, > only

Re: [TLS] Alternative ESNI?

2018-12-15 Thread Eric Rescorla
On Sat, Dec 15, 2018 at 12:41 PM Stephen Farrell wrote: > If browsers found one of the schemes attractive and the other > not, that'd I think be a winning argument - unfortunately, but > realistically, that'd win all arguments about trade-offs in > terms of potential for privacy improvement. > I

Re: [TLS] Alternative ESNI?

2018-12-15 Thread Viktor Dukhovni
[ After this comment, stepping back for a while, I want to hear what others think about the general shape of the alternative... ] > On Dec 15, 2018, at 3:40 PM, Stephen Farrell > wrote: > >> For opportunistic discovery, yes also DNS, but the DNS record would >> just hold a stable indication o

Re: [TLS] Alternative ESNI?

2018-12-15 Thread Stephen Farrell
Hiya, On 15/12/2018 20:00, Viktor Dukhovni wrote: > > >> On Dec 15, 2018, at 8:08 AM, Stephen Farrell >> wrote: >>e >> I don't see any point in considering the variant with the easy >> active attack though; > > For the record the easy MiTM attack requires on-path TCP termination, > only disc

Re: [TLS] Alternative ESNI?

2018-12-15 Thread Viktor Dukhovni
> On Dec 15, 2018, at 8:08 AM, Stephen Farrell > wrote: > > I don't see any point in considering the variant with the easy > active attack though; For the record the easy MiTM attack requires on-path TCP termination, only discloses the SNI name, and the full handshake then fails. It looks t

Re: [TLS] Alternative ESNI?

2018-12-15 Thread Eric Rescorla
On Fri, Dec 14, 2018 at 9:48 PM Nico Williams wrote: > On Fri, Dec 14, 2018 at 08:01:35PM -0800, Eric Rescorla wrote: > > On Fri, Dec 14, 2018 at 6:54 PM Nico Williams > wrote: > > > OpenSSL extracts and uses SNI from session resumption tickets. > > > This gave Viktor Dukhovni and Matt Caswell a

Re: [TLS] Alternative ESNI?

2018-12-15 Thread Stephen Farrell
Hi Nico, On 15/12/2018 02:53, Nico Williams wrote: > OpenSSL extracts and uses SNI from session resumption tickets. > > This gave Viktor Dukhovni and Matt Caswell an idea that I'll relay here > on their behalf. I agree this is worth exploring, though am not sure if it'd be better in the end. (I

Re: [TLS] Alternative ESNI?

2018-12-14 Thread Nico Williams
On Fri, Dec 14, 2018 at 08:01:35PM -0800, Eric Rescorla wrote: > On Fri, Dec 14, 2018 at 6:54 PM Nico Williams wrote: > > OpenSSL extracts and uses SNI from session resumption tickets. > > This gave Viktor Dukhovni and Matt Caswell an idea that I'll relay here > > on their behalf. > > > > Also, wh

Re: [TLS] Alternative ESNI?

2018-12-14 Thread Eric Rescorla
On Fri, Dec 14, 2018 at 6:54 PM Nico Williams wrote: > OpenSSL extracts and uses SNI from session resumption tickets. > > This gave Viktor Dukhovni and Matt Caswell an idea that I'll relay here > on their behalf. > > Also, while we're at it, I'd like to note that SNI is not the only thing > requi

[TLS] Alternative ESNI?

2018-12-14 Thread Nico Williams
OpenSSL extracts and uses SNI from session resumption tickets. This gave Viktor Dukhovni and Matt Caswell an idea that I'll relay here on their behalf. Also, while we're at it, I'd like to note that SNI is not the only thing requiring privacy protection from the client. There's also the PSK iden