Using the Shibboleth to Athens Gateway

WARNING: This page is retained as a historical record but is out-of-date and is not being maintained.

This was a working document belonging to the Computing Service's Shibboleth Development Project. This project is complete (Raven now supports Shibboleth) and this document only remains for historical and reference purposes. Be aware that it is not being maintained and may be misleading if read out of context.

The Shibboleth to Athens gateway allows people to authenticate using Shibboleth and then gain access to resources that are protected by Athens. The gateway is run under contract for JISC by EduServ - it appears that use of the gateway will be available at no cost to us until at least July 2011 - see this blog entry. The University currently (as at 2007-05-17) has 'testing' access via the gateway, but this means that it doesn't work quite as it will once in production (see below).

Note that our Shibboleth IdP, on which use of the gateway depends, is itself only a pilot (as at 2007-05-17) and liable to service interruptions without notice.

Access Control

Use of the gateway is currently controlled entirely by membership of groups in lookup. In due course many people will be automatically granted gateway access based on other information in lookup, and then membership of the groups will only be required for people who can't automatically be identified as being eligible. The groups are:

Shibboleth service Athens gateway overrides

Members of this group are granted access to the majority of Athens resources, corresponding to the cam#default0 Athens permission set. In due course, staff and students of the University will get access automatically and membership of this group will only be required to grant access to users who can't otherwise be identified.

Shibboleth service medical overrides

Members of this group are granted access to medically-restricted material, both via the gateway (corresponding to the cam#aaemo permission set) and directly via Shibboleth. In due course, some staff and students of the University will get this additional access automatically and membership of this group will only be required to grant access to users who can't otherwise be identified.

Shibboleth service Athens gateway blacklist

Members of this group are administratively prohibited from accessing any resources via the Shibboleth to Athens gateway. This group is provided to implement short-term blocks in response to misuse, etc. This prohibition applies both to members of the two groups above and to anyone receiving access automatically.

It is a limitation of the current implementation that membership of these three groups has to be visible within the University for it to work. If visibility is suppressed, either by the group's manager or the individual member, then the corresponding rights won't be available. This will be resolved in due course.

Membership of these three lists and other details about them are managed by the members of a fourth group, Shibboleth service lookup group managers. Members of this group can go to the 'Members' tab of any of these four lists and from there add or remove members. They can also edit other details of the four groups (such as title, access controls, etc.) but in general should avoid doing so.

Once you have authenticated to the gateway it caches the permission set(s) that were allocated to you for up to 8 hours. As a result, changes to group membership don't immediately affect access control decisions even if you quit your browser and restart.

Using the Gateway

Once in production it will (if I've got this right) be possible to use the gateway to access any Athens-protected resource (such as MyAthens) by navigating to the resource, following links to log in via Athens, selecting an 'Alternate login' (or similar) link, and choosing 'University of Cambridge' from the resulting dialogue (the 'Athens Home Domain Discovery Service', HDDS). This will take you to our Raven/Shibboleth service where you will identify yourself, 'log you in' to Athens, and then take you back to the resource you wanted.

However, since we are still in testing, doing this at the moment (2006-05) just throws up a box containing contact details. If you want to see what this will eventually look like, pretend you are from Cardiff - you'll be able to follow the sequence up to the point that Cardiff's equivalent to Raven asks for a user name and password.

For the time being, you should follow this link

https://auth.athensams.net/setsite.php?id=urn:mace:eduserv.org.uk:athens:provider:cam.ac.uk&ath_dspid=ATHENS.MY&ath_returl=%2Fmy

which will do exactly what selecting 'University of Cambridge' while trying to get to MyAthens will eventually do - confirm you want Cambridge, log you in to Athens and send you to MyAthens. Similar URL's could be constructed for any Athens service (MyAthens is just an example) by replacing the ath_dspid and/or ath_returl parameters with other values but doing so probably isn't important since this is all largely an artefact of the current 'testing' status of our gateway access.

Because you are 'logged in' to Athens you will be able to access further Athens resources directly during this browser session without further authentication. You will also now have a long term cookie (ath_ldom) which will cause your browser to automatically use the Cambridge shibboleth service by default for all future Athens authentication.

Alternatively you can follow this link

https://auth.athensams.net/setorg.php?id=urn:mace:eduserv.org.uk:athens:provider:cam.ac.uk&ath_returl=https%3a%2f%2fwiki.csx.cam.ac.uk%2fraven%2fUsing_the_Shibboleth_to_Athens_Gateway

which will just set the ath_ldom cookie if necessary and bring you back here. Subsequent attempts to access Athens resources will automatically be routed to Cambridge via the gateway, just as if you had previously accessed something like MyAthens as described above.

Having done all this, if you want to stop using the gateway and go back to using 'Classic Athens' then either delete the ath_ldom cookie set by the host auth.athensams.net, or select the 'I am not from Cambridge University Library' (sic.) link that is displayed before referring you to Cambridge.

This use of ath_ldom means that it's difficult to use gateway access and 'Classic Athens' during the same browser session. This will still happen once our use of the gateway is in production mode - once you have accessed any Athens resource via the gateway all your subsequent accesses during that session will automatically use the gateway. Apparently it is possible to use target resource locator (TRL) (see Athens DA Protocol) to construct special links which will will bypass the HDDS, allowing selected resources to be accessed by Classic Athens even when everything else is using the Gateway.

Note that, since many of our Athens-protected resources are available by IP address from within the University, it can be difficult to easily distinguish between access granted by address and access granted via the gateway when working from computers on the University network. Access to an external connection, e.g. NTL broadband, makes life easier.

Issues

1. For sites that support customisation and the like, note that your identity as established via the gateway is different to your identity established via 'Classic Athens' - you are in effect two different people.

2. Some sites are known not to work via the gateway. There a (depressingly long) list at http://www.athensams.net/allresources/nongatewayresources.aspx

Westlaw is one - the error message displayed (Description: Error getting sponsor based on prefix for: _wplsf6omk2rfw7lfveb - No Athens prefix found in DB.) confirms that they are still relying on the outdated practice of checking Athens ID prefixes to identify home institution, a practice that it incompatible with the gateway.

3. Even once in production, anyone navigating to a supplier site and choosing to authenticate via Athens will see big 'Username' and 'Password' boxes, as well as a small 'Alternate login' link. It will be a documentation/training challenge to convince them to follow the alternate login link and NOT to put their Raven userid and password into the boxes provided which won't work and which will compromise the security of their Raven account.

4. The gateway effectively 'creates' an Athens ID for everyone who uses it. This is a meaningless, 20 character string starting with an underscore that users will not in general recognise. Unfortunately some sites think it's a good idea to use it like a name e.g. Adept Scientific: "Special prices for _wplsf6omk2rfw7lfveb. As a member of Cambridge University Library you are eligible for...".

5. The fact that the gateway caches things like permission sets means that if someone tries and fails to gain access then, even after we add them to the relevant group, there is going to be a delay before they can access the resource that want.

6. What happens when someone not authorised to use the gateway tries to access resources through it will probably be confusing. They won't immediately be refused access, but if they accesses a resource directly and goes through the required discovery process, they are going to see an error at either the EduServ AP or from the resource provider telling them something along the lines of "You are logged into Athens but you do not have access to this resource" [example]. If they login to MyAthens they will be able to login but there will be no resources listed for them to login to [example].

7. Gateway (or AthensDA) doesn't work for Z39.50 (e.g. to Zetoc) and requires some sort of work-around for CrossFire via the CrossFire Commander client (see Sean Dunne <Sean.Dunne@MANCHESTER.AC.UK> to ATHENSDA@JISCMAIL.AC.UK, Fri, 26 Aug 2005)