InCommon Library Services

["David Kennedy" <>]

> As part of that conversation, Fiona asked some questions about the 
> OpenURL/sfx/EZProxy/sessionInitiator flow that we've explored. In 
> particular, she's asking about the role of EZP, and two of the steps we 
> have it doing (determining whether the target site is shib-enabled or not; 
> rewriting the url to  point to the sessionInitiator). She's wondering 
> whether the link resolver could also perform both of these functions...?

I can only speak to what SFX is capable of.  This can be done in SFX, but 
not cleanly.

SFX itself is not aware of shibboleth.  There is also no way, within SFX, to 
indicate whether or not a particular target is shib-enabled.  SFX can be 
configured to use a proxy server or not per target.

SFX resolves openURLs into actual URLs at the target site.  There is 
target-specific code for each target that is configured.  It is possible, 
although maybe not advised, to change the underlying code that resolves the 
URL for a particular target.  So, one could conceivably hard-code the 
session initiator URL into the code for a particular target site.  Some of 
the target-specific code takes parameters, and in some cases, one could 
include the sessioninitiator url into a passed parameter instead of altering 
underlying code.

There are a few reasons that I would not recommend this:
- One of the advantages of buying a software like SFX is that ExLibris 
maintains the URL resolving code for all of the vendors, and updates it 
regularly.  So, changing this code is done at your own risk.
- If an institution chooses to have SFX make the decision whether to use 
shib or not, every other place where URLs are presented (Metalib, 
blackboard, catalog, etc) will also have to be aware of shib and the session 
initiator url.
- If a target's code is modified to use the session initiator, this would be 
used whether a user is on campus or off campus.

Dave
----------------------
David Kennedy
Applications Developer
USMAI Libraries
McKeldin Library
College Park, MD 20742

(301) 405-9051
(301) 314-9865 (fax)
----- Original Message ----- 
From: <>
To: <>
Sent: Thursday, September 06, 2007 9:44 AM
Subject: [inc-librsvcs] capabilities of sfx/linkresolvers....


> The UK Federation will be having a conversation with Thomson ISI later 
> this week; I've relayed to them some of our recent conversations 
> (particularly the request that Thomson include the /Login sessionInitiator 
> in their config).
>
> As part of that conversation, Fiona asked some questions about the 
> OpenURL/sfx/EZProxy/sessionInitiator flow that we've explored. In 
> particular, she's asking about the role of EZP, and two of the steps we 
> have it doing (determining whether the target site is shib-enabled or not; 
> rewriting the url to  point to the sessionInitiator). She's wondering 
> whether the link resolver could also perform both of these functions...?
>
> I'm no expert on link resolvers... but many of you are.... would her 
> suggestion be viable?
>
> Thanks!
>
> > From: "Fiona Culloch" <>
> > To: <>
> > Cc: <>, "Ian Young" <>
> > Subject: RE: common set of attributes across federations
> > Date: Thu, 6 Sep 2007 14:20:58 +0100
> >  >
> > >  Are you familiar with EZP's Shib support?
> >
> > I'm not I'm afraid: as I mentioned previously, I haven't seen much
> > sign of it at all yet, though I'm sure some places here must be using it.
> >
> > However, I had a question about the scenario descriptions in your
> > previous mail.  Previously, my understanding was that the job of
> > a campus OpenURL resolver was to do precisely the kind of things
> > that in your scenarios you describe EZP as doing: mapping a single
> > static URL that references a document into the appropriate form
> > for local use, including any necessary authentication bells and whistles,
> > accommodating on/off-campus access, etc.
> >
> > Can you explain (or link to) what it is EZP can do that the OpenURL
> > resolver couldn't if it was appropriately configured?  I can easily
> > imagine that in a particular setting the people responsible for
> > configuring an OpenURL resolver can't or don't want to reconfigure it
> > to accommodate Shibboleth, but are happy to delegate that work
> > to a different group who maintain an EZP instance.  But is there a
> > technical reason that an OpenURL resolver isn't flexible enough to
> > do similar things itself?
> >
> > Fiona.