The IESG wrote:
The IESG has received a request from the Session Initiation Protocol WG (sip) to consider the following document:

- 'Framework for Establishing an SRTP Security Context using DTLS '
   <draft-ietf-sip-dtls-srtp-framework-04.txt> as a Proposed Standard


This document approval at the IESG level might signal a shift in the IETF consistent use of PKI security certificates for remote party authentication in (D)TLS protocols.

The present comment is submitted to make sure that the IESG decision is an educated one, and not made inedvertantly. If another document previously approved by the IESG is an accepted precedent for the subject matter discussed below, the present comment may be ignored.

The present comment is neither for or against advancement of the draft.

From the introduction section of the draft:

"The goal of this work is to provide a key negotiation technique that allows encrypted communication between devices with no prior relationships."

"The media is transported over a mutually authenticated DTLS session where both sides have certificates. It is very important to note that certificates are being used purely as a carrier for the public keys of the peers. This is required because DTLS does not have a mode for carrying bare keys, but it is purely an issue of formatting. The certificates can be self-signed and completely self-generated."

From these indications it is easy to see that the framework would (ideally) require a (D)TLS protocol derivative in which "bare" peer public keys can be carried without the burden of security certificate. Despite the above wording, the current lack of such a (D)TLS mode might be more than a mere "issue of formatting" - it might be a consequence of a long-standing policy at the IETF.

If this draft is approved by the IESG, it might signal that similar uses of self-signed-at-will (or otherwise meaningless) security certificates is an approved approach for circumventing the lack of a "bare public key" (D)TLS mode. Note that this is different from the PSK-TLS mode (pre-shared key) which explicitly relies on pre-established symmetric keys as a *replacement* for security certificate assurance.

It is my understanding that the self-signed-at-will (or otherwise meaningless) certificate approach is technically feasible but should remain standardized outside of the IETF activities, if at all. Based on this understanding, my draft draft-moreau-pkix-aixcm (that also falls in this broad approach) has been submitted as a non-IETF informational RFC. (A comparative analysis between the SIP draft and mine is a matter of implementation strategy for the overall approach, and is thus out of scope for the present comment.)
See http://www.rfc-editor.org/queue2.html#draft-moreau-pkix-aixcm .

In any event, this comment is made for the sole purpose of making IESG/IETF directions more explicit.

Thanks to Eric Rescorla who brought my attention to the similarities between the SIP draft and an early version of the ideas behind my draft.

Regards,


--

- Thierry Moreau

CONNOTECH Experts-conseils inc.
9130 Place de Montgolfier
Montreal, Qc
Canada   H2M 2A1

Tel.: (514)385-5691
Fax:  (514)385-5900

web site: http://www.connotech.com
e-mail: [EMAIL PROTECTED]

_______________________________________________
Ietf mailing list
Ietf@ietf.org
https://www.ietf.org/mailman/listinfo/ietf

Reply via email to