[Go-essp-tech] resolution on securing opendap aggregations via ESGF

Gavin M. Bell gavin at llnl.gov
Mon May 23 19:06:01 MDT 2011


Hi Luca,

I think that the separation of concerns trumps the apparent
"simplicity".  Though it is apparently easy to republish (I am not sure
I fully agree with that, at least not from the anecdotal information I
hear from folks)... it is unnecessary to publish if we keep concerns
separated.

As Estani said, the publisher publishes and does basic mechanical sanity
checks on data.  That should be the full extent of its operation.  As
far as what is easy... one could 'easily' set up an index over the CIM
info and "join" on datasetid.  This also provides loose coupling.  If
the CIM system has issues, that just means that when you look at your
search results you won't see CIM info, but you will still see the
dataset and be able to fetch and manipulate it and everything else. 
Also if the CIM changes it doesn't affect the pubblisher or publishing
in any way.  Catalogs should be viewed as "files" in the system... they
essentially are logical files (containing pointers to physical files).

I am still not convinced by your arguments that fusing and coupling
these two semantically different aspects of the system so tightly is the
right long term architectural solution.  It may be good now, but it not
as flexible later. We should leave open the avenue for other
meta-metadata to be imbued onto our system ex-post-facto without much ado.

my $0.02

On 5/23/11 2:08 AM, stephen.pascoe at stfc.ac.uk wrote:
> I'm with Estani on this.  Authorisation decisions are best decoupled from the application where possible.  Phil is on leave today but I'm sure he'd say the same thing and give much more detailed reasoning.  
>
> I think the catalogue already mixes slightly too much information together: location-independent file metadata and location-specific service information.  If we add access control it becomes too tightly coupled.
>
> Stephen.
>
> ---
> Stephen Pascoe  +44 (0)1235 445980
> Centre of Environmental Data Archival
> STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, UK
>
>
> -----Original Message-----
> From: go-essp-tech-bounces at ucar.edu [mailto:go-essp-tech-bounces at ucar.edu] On Behalf Of Estanislao Gonzalez
> Sent: 21 May 2011 09:30
> To: Cinquini, Luca (3880)
> Cc: go-essp-tech at ucar.edu
> Subject: Re: [Go-essp-tech] resolution on securing opendap aggregations via ESGF
>
> Hi,
>
> In my opinion we shouldn't encode the access restriction in the catalog 
> for these reasons:
> 1) Changing the access would involved re-publishing the files. (this 
> will be done for instance when QC L2 is reached CMIP5 Research -> CMIP5 
> Commercial). And think about what would happen if we want to change the 
> access restriction in a couple of years... we should publish everything 
> again, and that would involve quite some effort to understand the 
> procedure again...
> 2) I'm not sure of this, but I fear TDS security cannot handle multiple 
> roles. Right now you can publish to as many roles as required, and read 
> and write access is kept separately. This would involve extending the 
> TDS capabilities.
> 3) There could be potential inconsistencies if the authorization service 
> is detached from datanode (like with the gateway right now) and the 
> publisher alters the role but forgets to cascade the changes to the 
> authorizing service (which would proceed according to the last harvested 
> info)
> 4) And last but not least, I'm not sure we want to mix administration 
> with publication. The publisher should only care about making data 
> available, the administrator should organize this and be responsible for 
> the security.
>
> So basically I don't agree :-) Although I do think, if required, we 
> could change "esg-user" for "esgf-controlled" if it's more intuitive.
>
> My 2c anyways,
> Estani
>
> Am 20.05.2011 19:17, schrieb Cinquini, Luca (3880):
>> Hi,
>> 	a few points again on the issue of securing opendap aggregations served by the TDS with ESGF filters:
>>
>> o There's a new release of the ESGF security filters (esg-orp 1.1.2) that maps the TDS request URI to the dataset ID, and should solve this problem. You can experiment with the JPL test TDS server:
>>
>> http://test-datanode.jpl.nasa.gov/thredds/catalog.html
>>
>> where the AIRS dataset (and aggregations) is secured, the MLS is not.
>>
>> o Now the data node authorization filter will correctly identify the aggregation as secured, and call the configured authorization service. Currently, the p2p Node authorization service can be configured to allow authorization based on URL matching, so it will work. The gateway authorization service will have to implement its own logic to establish authorization.
>>
>> o Finally, I am wondering if we shouldn't change the way we encode authorization in thredds catalogs. Right now, we use restrictAccess="esg-user" for ALL collections, but should we consider about encoding the proper required access control attribute instead, for example restrictAccess="CMIP5 Research" ? Something to think about - there are prons and cons about this - it's all a question on wether the access control belongs in the catalog (and can be harvested for searching...) or not.
>>
>> thanks, Luca
>> _______________________________________________
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>

-- 
Gavin M. Bell
--

 "Never mistake a clear view for a short distance."
       	       -Paul Saffo


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