RE: [TLS] GSS based PSK-TLS

Larry Zhu <lzhu@windows.microsoft.com> Tue, 17 July 2007 22:40 UTC

Return-path: <tls-bounces@lists.ietf.org>
Received: from [127.0.0.1] (helo=stiedprmman1.va.neustar.com) by megatron.ietf.org with esmtp (Exim 4.43) id 1IAvim-0008Ba-5k; Tue, 17 Jul 2007 18:40:44 -0400
Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1IAvik-00088Y-2e for tls@ietf.org; Tue, 17 Jul 2007 18:40:42 -0400
Received: from mailb.microsoft.com ([131.107.115.215] helo=smtp.microsoft.com) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1IAvii-0001iG-Rh for tls@ietf.org; Tue, 17 Jul 2007 18:40:42 -0400
Received: from tk1-exhub-c102.redmond.corp.microsoft.com (157.56.116.113) by TK5-EXGWY-E802.partners.extranet.microsoft.com (10.251.56.168) with Microsoft SMTP Server (TLS) id 8.0.700.0; Tue, 17 Jul 2007 15:40:40 -0700
Received: from win-imc-02.wingroup.windeploy.ntdev.microsoft.com (157.54.69.169) by tk1-exhub-c102.redmond.corp.microsoft.com (157.56.116.113) with Microsoft SMTP Server id 8.0.726.0; Tue, 17 Jul 2007 15:40:39 -0700
Received: from WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com ([157.54.62.25]) by win-imc-02.wingroup.windeploy.ntdev.microsoft.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 17 Jul 2007 15:40:39 -0700
X-MimeOLE: Produced By Microsoft Exchange V6.5
Content-Class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Subject: RE: [TLS] GSS based PSK-TLS
Date: Tue, 17 Jul 2007 15:40:10 -0700
Message-ID: <CAAAEFE273EAD341A4B02AAA9CA6F73306BB9A73@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com>
In-Reply-To: <200707172141.l6HLfqU9000857@fs4113.wdf.sap.corp>
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
Thread-Topic: [TLS] GSS based PSK-TLS
Thread-Index: AcfIu1MBtrWytsHnQga/Cm3wjwUK3gAB3EFg
References: <CAAAEFE273EAD341A4B02AAA9CA6F73306AF946A@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> from "Larry Zhu" at Jul 13, 7 04:46:12 pm <200707172141.l6HLfqU9000857@fs4113.wdf.sap.corp>
From: Larry Zhu <lzhu@windows.microsoft.com>
To: martin.rex@sap.com
X-OriginalArrivalTime: 17 Jul 2007 22:40:39.0234 (UTC) FILETIME=[7FD74220:01C7C8C3]
X-Spam-Score: -108.0 (---------------------------------------------------)
X-Scan-Signature: 4b800b1eab964a31702fa68f1ff0e955
Cc: tls@ietf.org
X-BeenThere: tls@lists.ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.lists.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@lists.ietf.org?subject=unsubscribe>
List-Archive: <http://www1.ietf.org/pipermail/tls>
List-Post: <mailto:tls@lists.ietf.org>
List-Help: <mailto:tls-request@lists.ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@lists.ietf.org?subject=subscribe>
Errors-To: tls-bounces@lists.ietf.org

Martin Rex wrote:
> TLS session can be cached, resumed and forked.  Although performance
is an issue for a significant amount of our customers, the RSA-server-
> authentication in the SSL handshake is NOT normally an issue (it only
becomes an issue if the SSL session cache is configured too small).
So-called 
> SSL Accellerators have a really hard time to provide a benefit.  They
might add latency and an additional point of failures, and can hardly
keep up 
> with x86-based multi-cpu multi-core machines (both in terms of price
and performance).

This will continue to work. I would like to emphasize FKA-TLS is a
variant of PSK-TLS.


> GSS-API security context can not be cached and not be resumed.

you do not need to resume in the GSS level. You can resume in the
PSK-TLS level. Again, this is a variant of PSK-TLS, you have all the
bells and whistlers of PSK-TLS.

--larry

-----Original Message-----
From: Martin Rex [mailto:Martin.Rex@sap.com] 
Sent: Tuesday, July 17, 2007 2:42 PM
To: Larry Zhu
Cc: tls@ietf.org
Subject: Re: [TLS] GSS based PSK-TLS

Larry Zhu wrote:
> 
> We would like to request for comments for the GSS based PSK-TLS ID:
> 
> http://www.ietf.org/internet-drafts/draft-santesson-tls-gssapi-02.txt
> 
> 2) Why the GSS handshake does not come after the key exchange message?
> 
> We do not want to pay for the cost of the DHE or RSA in this case. 
> The main motivation for us is to enable Kerberos to secure TLS
> connections. 
> Kerberos is a lot faster, and we intend to keep it that way.

TLS session can be cached, resumed and forked.  Although performance
is an issue for a significant amount of our customers, the
RSA-server-authentication in the SSL handshake is NOT normally
an issue (it only becomes an issue if the SSL session cache is
configured too small).  So-called SSL Accellerators have a really
hard time to provide a benefit.  They might add latency and an
additional point of failures, and can hardly keep up with x86-based
multi-cpu multi-core machines (both in terms of price and performance).


GSS-API security context can not be cached and not be resumed.

A while ago I looked with HTTPWatch at the messages exchanged
between MSIE6 and IIS6 using HTTPS+Negotiate.  IIS6 forces
the client with 401 Unauthorized through a full new Kerberos
authentication with each and every request on an established
TLS channel.  I'm not impressed, and will not easily buy
"proposed solutions" for Microsoft-asserted performance issues.


And why is TLS authentication performance made a non-issue
for StartTLS vs FastArmor and a big issue here?


-Martin


_______________________________________________
TLS mailing list
TLS@lists.ietf.org
https://www1.ietf.org/mailman/listinfo/tls