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WARNING: This page is retained as a historical record but is out-of-date and is not being maintained.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

Note that when you authenticate to the gateway, it seems to cache various bits of information about you including your permissions. Because of this, changes to group membership don't immediately affect access control decisions even if you quit your browser and restart. I suspect that some/most/all cache entries expire within an hour or so.

Using the Gateway

Once in production it will (I think) be possible to access any Athens-protected resource using the gateway by navigating to the resource, following links to log in via Athens, selecting the 'Alternate login' (or similar) link, and choosing 'University of Cambridge' from the resulting dialogue. However, since we are still in testing, doing this just throws up a box containing contact details.

For the time being, you first have to authenticate using a manually-entered URL. The following URL will authenticate you and give you access to the EduServ 'My Athens' service:

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

I suspect that similar URL's can be constructed for a different service by replacing ATHENS.MY in the ath_dspid parameter with the internal Athens code for the service. I haven't yet worked out how to find these codes, but this may not be important since this is all largely an artefact of the current 'testing' status of our gateway access.

As I understand it, the gateway authentication process sets a cookie so that any subsequent access to any Athens resource during your current browser session, both via links from My Athens and direct from supplier sites, will automatically use the gateway route, which may mean that they 'just work' without further action by you. 'Normal' behaviour will be resumed if you quit and restart your browser - note that this means that you can't use gateway access and 'Classic Athens' during the same browser session. It is my understanding that 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.

Note that, since many of our Athens-protected resources are available by IP address from within the University, it may be difficult to easily distinguish between access granted by address and access granted via the gateway when working from computers on the University network.

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].