Subject: I-D Action:draft-ietf-pkix-ocspagility-02.txt

From: [email-masked]
Date: Wed, 12 Aug 2009 06:15:01 -0700 (PDT)

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Public-Key Infrastructure (X.509) Working Group of the IETF.

	Title           : OCSP Algorithm Agility
	Author(s)       : P. Hallam-Baker, S. Santesson
	Filename        : draft-ietf-pkix-ocspagility-02.txt
	Pages           : 9
	Date            : 2009-08-12

The OSCP specification defined in RFC 2560 requires server responses
to be signed but does not specify a mechanism for selecting the
signature algorithm to be used leading to possible interoperability
failures in contexts where multiple signature algorithms are in use.
This document specifies an algorithm for server signature algorithm
selection and an extension that allows a client to advise a server
that specific signature algorithms are supported.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-pkix-ocspagility-02.txt

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From: Sean Turner <[email-masked]>
Date: Sun, 16 Aug 2009 09:58:00 -0400

Is this ID intended to be an update of RFC 2560?  If so, then it should
indicate as much on the 1st page's header.

Shouldn't this be standards track and not informational track
(http://www.ietf.org/proceedings/73/minutes/pkix.htm)?

Sec 3: In the para after the ASN.1 snippet, I think we should add "The
object identifiers (OIDs) are listed in order of their preference" or
something similar.

Sec 4.1 bullet #5 makes me ask if the required algorithms in this
version of OCSP (RFC 2560) are DSA/RSA (must/should) with SHA-1 (must),
then are responses signed with RSA and SHA-256 considered non-compliant
with RFC 2560?  Also, the requirements in Sec 4.3 of RFC 2560 are for 
the client with the exception of SHA-1 so it seems like there might be a 
disconnect because there is no explicit server musts use X algorithm.

spt

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From: Stefan Santesson <[email-masked]>
Date: Mon, 17 Aug 2009 08:10:27 +0200

In line;

> indicate as much on the 1st page's header.

Yes it should, I'll add.

> (http://www.ietf.org/proceedings/73/minutes/pkix.htm)?
I think that is also correct. I'll update unless I hear objections.

> object identifiers (OIDs) are listed in order of their preference" or

Good suggestion

> with RFC 2560? 

No, I can't see that the draft claims this, or that we would like to say
this. First of all, this list is optional (Given by the first sentence of
4.1)

> Also, the requirements in Sec 4.3 of RFC 2560 are for
Well, the server would naturally select one algorithm that is supported by
the clients.

But with respect to the OCSP agility document, maybe could improve the
guidelines if we say the following instead:

   5.  Using a mandatory or recommended signing algorithm specified for
       the version of the OCSP protocol in use.

/Stefan