Re: [TLS] rfc4366-bis: Certificate Status for intermediate CA

Martin Rex <Martin.Rex@sap.com> Tue, 29 September 2009 00:58 UTC

Return-Path: <Martin.Rex@sap.com>
X-Original-To: tls@core3.amsl.com
Delivered-To: tls@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 465413A68BB for <tls@core3.amsl.com>; Mon, 28 Sep 2009 17:58:08 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -5.898
X-Spam-Level:
X-Spam-Status: No, score=-5.898 tagged_above=-999 required=5 tests=[AWL=0.351, BAYES_00=-2.599, HELO_EQ_DE=0.35, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vsaJATKMfKlh for <tls@core3.amsl.com>; Mon, 28 Sep 2009 17:58:07 -0700 (PDT)
Received: from smtpde03.sap-ag.de (smtpde03.sap-ag.de [155.56.68.140]) by core3.amsl.com (Postfix) with ESMTP id 446E43A688C for <tls@ietf.org>; Mon, 28 Sep 2009 17:58:06 -0700 (PDT)
Received: from mail.sap.corp by smtpde03.sap-ag.de (26) with ESMTP id n8T0xO9n027984 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 29 Sep 2009 02:59:24 +0200 (MEST)
From: Martin Rex <Martin.Rex@sap.com>
Message-Id: <200909290059.n8T0xNqH020479@fs4113.wdf.sap.corp>
To: yngve@opera.com (Yngve N. Pettersen)
Date: Tue, 29 Sep 2009 02:59:23 +0200 (MEST)
In-Reply-To: <op.u0zl0wlcqrq7tp@acorna.oslo.opera.com> from "Yngve N. Pettersen" at Sep 28, 9 11:59:10 pm
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Scanner: Virus Scanner virwal06
X-SAP: out
Cc: tls@ietf.org
Subject: Re: [TLS] rfc4366-bis: Certificate Status for intermediate CA
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
Reply-To: martin.rex@sap.com
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/tls>
List-Post: <mailto:tls@ietf.org>
List-Help: <mailto:tls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 29 Sep 2009 00:58:08 -0000

Yngve N. Pettersen wrote:
> 
> However, sending two CertificateStatusRequest extensions in the same  
> ClientHello is forbidden by RFC 5246 sec 7.4.1.4:
> 
>     When multiple extensions of different types are present in the
>     ClientHello or ServerHello messages, the extensions MAY appear in any
>     order.  There MUST NOT be more than one extension of the same type.

How about always using the existing extension for the OCSP response
for the server certificate, and using a new extension for OCSP responses
for other certificates (like intermediate CA certs), probably unsorted.

PKIs with flat hierarchies (Server-cert signed by self-signed CA cert)
use only the original extension.  Servers with certs from multi-level
CA hierarchies need to use the new extension if they want to send
additional OCSP responses.

-Martin