Subject: [saag] Proposal for OCSP over DNS

From: "Dr. Pala" <[email-masked]>
Date: Mon, 23 Oct 2017 14:54:29 -0600

Hi all,

we are currently working on specifying how to use DNS as a transport 
protocol for revocation information for X509 certificates. In 
particular, we are working on how to leverage the distributed nature of 
DNS to efficiently (and at lower operational costs) distribute OCSP 
responses to applications/devices/etc.

We started this work sometime ago but never really had the time to 
finish it. Now it seems we can focus more on the topic and would like to 
discuss this work in a more public venue.

We currently have two similar I-D submitted (that should probably be 
re-edited and merged):

  * https://datatracker.ietf.org/doc/draft-pala-odin/
  * https://datatracker.ietf.org/doc/draft-pala-rea-ocsp-over-dns/

EKR suggested that this may be another topic for the SEC-DISPATCH 
meeting. Can we have 5-10 minutes for this @IETF100 ?

Cheers,
Max

-- 
Best Regards,
Massimiliano Pala, Ph.D.
OpenCA Labs Director
OpenCA Logo

---

From: "Paul Hoffman" <[email-masked]>
Date: Mon, 23 Oct 2017 14:13:51 -0700

On 23 Oct 2017, at 13:54, Dr. Pala wrote:

> particular, we are working on how to leverage the distributed nature 
> of DNS to efficiently (and at lower operational costs) distribute OCSP 
> finish it. Now it seems we can focus more on the topic and would like 
> to discuss this work in a more public venue.
>

These sound like "we want HTTP over UDP to save latency, so we'll just 
substitute DNS". That's certainly an option, but it hasn't been a 
popular route in the IETF. Are the busy CAs asking for this? Is there a 
reason why they can't just beef up their web infrastructure (like their 
customers are)?

--Paul Hoffman

---

From: "Dr. Pala" <[email-masked]>
Date: Mon, 23 Oct 2017 15:38:43 -0600

Hi Paul, all,

the way I personally see this is not only related to Internet CAs / 
website-oriented TLS, but also as a way to distribute the revocation 
information in environments where entities (devices, software, etc.) 
might be restricted from accessing the global Internet but still allowed 
to query the DNS. Entities leveraging specific trust environments (e.g., 
OCF, CMI, etc. ) might especially benefit from this additional 
distribution mechanism (which is not in competition with existing 
solutions :D)

Beefing up CAs web infrastructures is what CAs have been doing so far - 
AFAIK, however that comes at high operational costs that have to be 
covered somehow :D I think that it will be useful to have an alternative 
that can be as efficient (if not even more efficient), distributed (info 
get closer to the client), and that comes at (potentially) lower 
operational costs.

Just my 2 cents...

Cheers,
Max

On 10/23/17 3:13 PM, Paul Hoffman wrote:
>> of DNS to efficiently (and at lower operational costs) distribute 
>> OCSP responses to applications/devices/etc.
>>
> popular route in the IETF. Are the busy CAs asking for this? Is there 
> a reason why they can't just beef up their web infrastructure (like 
> their customers are)?
>
> --Paul Hoffman

-- 
Best Regards,
Massimiliano Pala, Ph.D.
OpenCA Labs Director
OpenCA Logo

---

From: "Dr. Pala" <[email-masked]>
Date: Thu, 26 Oct 2017 15:59:06 -0600

Hi all,

I just want to let everybody know that we manage to send in the latest 
version of the draft that better organizes the text and incorporates the 
previous work / I-Ds into one:

    https://datatracker.ietf.org/doc/draft-pala-odin

comments, feedback, etc. always welcome :D

Cheers,
Max

On 10/23/17 3:38 PM, Dr. Pala wrote:
> might be restricted from accessing the global Internet but still 
> allowed to query the DNS. Entities leveraging specific trust 
> environments (e.g., OCF, CMI, etc. ) might especially benefit from 
> this additional distribution mechanism (which is not in competition 
> with existing solutions :D)
>
> Beefing up CAs web infrastructures is what CAs have been doing so far 
> - AFAIK, however that comes at high operational costs that have to be 
> covered somehow :D I think that it will be useful to have an 
> alternative that can be as efficient (if not even more efficient), 
> distributed (info get closer to the client), and that comes at 
> (potentially) lower operational costs.
>
> Just my 2 cents...
>
> Cheers,
> Max
>
>
>>> finish it. Now it seems we can focus more on the topic and would 
>>> like to discuss this work in a more public venue.
>>>
>> These sound like "we want HTTP over UDP to save latency, so we'll 
>> just substitute DNS". That's certainly an option, but it hasn't been 
>> a popular route in the IETF. Are the busy CAs asking for this? Is 
>> there a reason why they can't just beef up their web infrastructure 
>> (like their customers are)?
>>
>> --Paul Hoffman
>
> -- 
> Best Regards,
> Massimiliano Pala, Ph.D.
> OpenCA Labs Director
> OpenCA Logo
>
>
> _______________________________________________
> saag mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/saag

---

From: Phillip Hallam-Baker <[email-masked]>
Date: Fri, 27 Oct 2017 08:16:45 -0400

On Mon, Oct 23, 2017 at 5:13 PM, Paul Hoffman <[email-masked]> wrote:
>> protocol for revocation information for X509 certificates. In particular, we
>> are working on how to leverage the distributed nature of DNS to efficiently
>> (and at lower operational costs) distribute OCSP responses to
>> applications/devices/etc.
>>
>> We started this work sometime ago but never really had the time to finish
>> it. Now it seems we can focus more on the topic and would like to discuss
>> this work in a more public venue.
>>
>> EKR suggested that this may be another topic for the SEC-DISPATCH meeting.
>> Can we have 5-10 minutes for this @IETF100 ?
>
>
> substitute DNS". That's certainly an option, but it hasn't been a popular
> route in the IETF. Are the busy CAs asking for this? Is there a reason why
> they can't just beef up their web infrastructure (like their customers are)?

Since QUIC is 'TCP++ over UDP' and flavor of the month, OCSP over QUIC
is probably a more viable route.

The expiry of the Micali and Kocher efficient revocation patents mean
that we now have options beyond OCSP which is what we are currently
focused on at Comodo.

I have proposed OCSP over DNS several times in the past. The problem I
ran into was that the chief concern of the browser providers is
latency. And some are unwilling to accept any proposal that increases
latency in any way for the sake of public safety.

Attempting to use DNS as transport is highly problematic. Many
networks block unknown RRs for a start. It is hard enough to get
DNSSEC to work right.

That led me to an approach where the OCSP and DNS lookups were
combined into one UDP transaction to a trusted discovery service
combining DNS lookup, OCSP and certificate fetch, aka 'omnibroker'.
That is an approach I will probably be revisiting in the near future.