Hi Dennis,

> I can see two different ways to handle it. Either as you suggest, we have it 
> be a runtime decision and we just prefix the compressed form with a byte to 
> indicate whether pass 2 has been used. Alternatively, we can define two 
> codepoints, (pass 1 + pass 2, pass 1).
> I'd like to experiment with both operations and measure what the real world 
> difference is first, then we can make a decision on how to proceed. There's 
> also been more interest in the non-webpki use case than I expected, so that 
> needs to factor in to whichever option we pick.

Maybe these will not matter for the scenario I am considering. Let’s say the 
client advertised support for draft-ietf-tls-cert-abridge. And the server sent 
back
- CompressedCertificate which includes the 2 identifiers for the ICA and RootCA 
from Pass 1.
- uncompressed, traditional CertificateEnty of the end-entity certificate

Or it sent back

- uncompressed, traditional CertificateEnties for the  ICA and RootCA certs
- CompressedCertificate which includes the ZStandard compressed (based on the 
Pass2 dictionary) end-entity cert

My point is that nothing should prevent the client from being able to handle 
these two scenarios and normative language should point that out. Any software 
that can parse certs in compressed form, ought to be able to parse them in 
regular form if the server did not support Pass1 (CA cers were not available 
for some reason) or Pass2 (eg. if CT Logs were not available for some reason).

Am I overseeing something?


From: Dennis Jackson <ietf=40dennis-jackson...@dmarc.ietf.org>
Sent: Monday, March 4, 2024 10:47 AM
To: Kampanakis, Panos <kpa...@amazon.com>; TLS List <tls@ietf.org>
Subject: RE: [EXTERNAL] [TLS] draft-ietf-tls-cert-abridge Update


CAUTION: This email originated from outside of the organization. Do not click 
links or open attachments unless you can confirm the sender and know the 
content is safe.



Hi Panos,

On 02/03/2024 04:09, Kampanakis, Panos wrote:
Hi Dennis,

I created a git issue 
https://github.com/tlswg/draft-ietf-tls-cert-abridge/issues/23 but I am pasting 
it here for the sake of the discussion:

What does the client do if the server only does Pass 1 and compresses / omits 
the chain certs but does not compress the end-entity certs (Pass 2)?

The client should be fine with that. It should be able to reconstruct the chain 
and used the uncompressed end-entity cert. It should not fail the handshake. I 
suggest the Implementation Complexity Section to say something like

I can see two different ways to handle it. Either as you suggest, we have it be 
a runtime decision and we just prefix the compressed form with a byte to 
indicate whether pass 2 has been used. Alternatively, we can define two 
codepoints, (pass 1 + pass 2, pass 1).

I'd like to experiment with both operations and measure what the real world 
difference is first, then we can make a decision on how to proceed. There's 
also been more interest in the non-webpki use case than I expected, so that 
needs to factor in to whichever option we pick.

Best,
Dennis

> Servers MAY chose to compress just the cert chain or the end-certificate 
> depending on their ability to perform Pass 1 or 2 respectively. Client MUST 
> be able to process a compressed chain or an end-entity certificate 
> independently.

Thanks,
Panos


From: TLS <tls-boun...@ietf.org><mailto:tls-boun...@ietf.org> On Behalf Of 
Dennis Jackson
Sent: Friday, March 1, 2024 8:03 AM
To: TLS List <tls@ietf.org><mailto:tls@ietf.org>
Subject: [EXTERNAL] [TLS] draft-ietf-tls-cert-abridge Update


CAUTION: This email originated from outside of the organization. Do not click 
links or open attachments unless you can confirm the sender and know the 
content is safe.



Hi all,

I wanted to give a quick update on the draft.

On the implementation side, we have now landed support for TLS Certificate 
Compression in Firefox Nightly which was a prerequisite for experimenting with 
this scheme (thank you to Anna Weine). We're working on a rust crate 
implementing the current draft and expect to start experimenting with abridged 
certs in Firefox (with a server-side partner) ahead of IETF 120.

On the editorial side, I've addressed the comments on presentation and 
clarification made since IETF 117 which are now in the editors copy - there's 
an overall diff here [1] and atomic changes here [2] . There are two small PRs 
I've opened addressing minor comments by Ben Schwarz on fingerprinting 
considerations [3] and Jared Crawford on the ordering of certificates [4]. 
Feedback is welcome via mail or on the PRs directly.

Best,
Dennis

[1] 
https://author-tools.ietf.org/api/iddiff?doc_1=draft-ietf-tls-cert-abridge&url_2=https://tlswg.github.io/draft-ietf-tls-cert-abridge/draft-ietf-tls-cert-abridge.txt

[2] https://github.com/tlswg/draft-ietf-tls-cert-abridge/commits/main/

[3] https://github.com/tlswg/draft-ietf-tls-cert-abridge/pull/21/files

[4] https://github.com/tlswg/draft-ietf-tls-cert-abridge/pull/19/files
_______________________________________________
TLS mailing list
TLS@ietf.org
https://www.ietf.org/mailman/listinfo/tls

Reply via email to