[ogsa-wg] Authentication in OGSA

Mon Jan 22 02:19:16 CST 2007

Hi Andrew and the OGSA-WG,

I apologize for missing the meeting last Thursday on this topic.  We  
have a machine full of new cluster and grid equipment, and I have  
been fully occupied commissioning and configuring it.

I am afraid that I differ rather strongly with the direction being  
taken with regard to the HPC profile at this stage.  My view is  
strongly that simple username/password login, even SSL secured, is  
quite demonstrably insufficiently secure to deploy as a model for  
authentication and access to high performance computing.  I disagree  
fairly strongly that any sort of stop-gap of this nature should be  
written into the HPC profile, distributed or promoted at this time.

I have an excuse for having taken so long to reply on this topic.  It  
was necessary for me to investigate as thoroughly as possible the  
current state of deployment of GSI-secured alternatives to username/ 
password login and to do so in a way that would allow me to give a  
credible response to all of you regarding the state of the art on  
this topic.

At this point I am assured and feel sufficiently confident to  
proceed, either at OGF-19 or before, with Andrew, Marty, and whoever  
else would like to participate on a revision of the HPC profile that  
would cover more secure basic access to high performance cluster and  
storage systems based on GSIOpenSSH and similar software that uses  
either GT4 or an equivalent callout.  We are writing standards, not  
implementations, but I wished to be sure that the state of the art on  
existing implementations would be consistent with making this  
recommendation.

It is essential from my point of view to promote secure access to HPC  
resources.  As the bulk of the compromise attacks that have been  
successful over the past 2 to 3 years on HPC resources has been  
through discovery and reuse of username/password combinations from  
ordinary users (at least as I read the recent record), I think that  
now is not the right time to propose backing off from the use of  
strong cryptographic methods to use HPC resources in grid settings.   
The use of strong cryptography does not have to be limited to X.509  
"pure classic" PKI, and I look forward to an active discussion on  
federated identity and related topics to be held at the OGF meeting  
next week.  It is clear to me that recent improvements to the  
availability and technology for authentication, authorization and  
attribute transmission will make many modes of access to grid  
resources possible with appropriate security that up to now have been  
either impossible or confined to limited implementation.

For the moment, I would like to suggest that a revision of the HPC  
profile propose that "only GSI or equivalently secure architectures  
be used for direct access to HPC resources" and that the document be  
revised specifically to discourage the direct access by users to  
highly capable computational and to secure storage resources by  
username/password mechanisms.  In my own project, we use GSI-OpenSSH  
via grid-mapfiles.  I have been able to confirm that current  
implementations of GSI-OpenSSH are capable of interoperating with  
more general callout-based systems, including attribute-based AuthZ  
systems, without modification.  Therefore it is not necessary for  
users to have username/password access if direct login is needed on  
an HPC system.

As a further enhancement to the document and to the profile, I feel  
it would be useful to describe architectures for pure-computational  
(i.e., batch-only access), for pure-login (i.e., front-end and  
submission access), pure-storage (i.e., stage-in/stage-out and  
related data handling) and for the interesting use case of "managed  
fork" (i.e., interactive but sand-boxed grid access) systems.  I  
believe these changes would result in an improved HPC profile that  
would be of better total usability within the HPC community.  This  
document is NOT attached, instead your original one is for  
discussion, but I believe can be worked out in the context of  
discussions to be held at OGF-19 next week.

Sorry for being (apparently but not really) strident, but I believe  
the above reflects current best practices better than recommending  
username/password support for direct login to HPC systems.  I would  
not personally be able to support the current draft as written.

Thanks and best wishes,
Alan

On Jan 18, 2007, at 2:16 PM, Andrew Grimshaw wrote:

> All,
>
> On this mornings call I volunteered to see what was up with the HPC  
> profile working group with respect to authentication.  Recall that  
> we need some sort of authentication story in the short run or we  
> cannot put together any form or realistic, cross-organizational,  
> compute grids with BES, or for that matter data grids using RNS/ 
> ByteIO.
>
>
>
> Attached is a short white paper from the HPC Profile WG (or maybe  
> just the three authors). It is BES-specific, but I think the ideas  
> may be generalized to a broader set of OGSA services. I think we  
> should consider it, or something like it.
>
>
>
> Note that it does NOT deal with the ultimate authentication and  
> delegation problem that we will face. Rather, I personally  
> (speaking only for myself, and not even the people in my research  
> group) think that this sort of solution is a stop gap that we can  
> use for awhile, and that we will ultimately deprecate in favor of  
> whatever comes out of the OGSA-Authentication WG.
>
>
>
> So, for your reading pleasure – and with my thanks to Marty for  
> giving me a copy.
>
>
>
> A
>
>
>
>
>
>
>
> Andrew Grimshaw
>
> Professor of Computer Science
>
> University of Virginia
>
> 434-982-2204
>
> grimshaw at cs.virginia.edu
>
>  --
>
>   ogsa-wg mailing list
>   ogsa-wg at ogf.org
>   http://www.ogf.org/mailman/listinfo/ogsa-wg

-------------- next part --------------
A non-text attachment was scrubbed...
Name: Security Considerations for the HPC Profile.pdf
Type: application/pdf
Size: 119111 bytes
Desc: not available
Url : http://www.ogf.org/pipermail/ogsa-wg/attachments/20070122/7cdd5c5c/attachment-0001.pdf 
-------------- next part --------------

Alan Sill, Ph.D
TIGRE Senior Scientist, High Performance Computing Center
Adjunct Professor of Physics
TTU

====================================================================
:  Alan Sill, Texas Tech University  Office: Admin 233, MS 4-1167  :
:  e-mail: Alan.Sill at ttu.edu   ph. 806-742-4350  fax 806-742-4358  :
====================================================================