The SWITCH aai identity federation is based on one important concept: The separation of identity management (IdM) and access management (AM). Identity providers are trusted sources of a set of well defined attributes. For each user trying to access a service, the service itself decides based on his/her attributes if access to the service is granted or denied.
The identity provider in its purest form only manages general user information like name, age, email address, membership status at a university etc. This information is general and not specific to services. The service specific part is the way how attribute information can be combined by a service to build complex access rules like: “This service accepts math students and staff members”.
What if a group of services needs to share additional information about a user that is not part of the standard attribute set? For this case SWITCH has developed the shared attribute service for the edu-ID.
The shared attribute service consists of a database where additional attributes can be stored for each SWITCH edu-ID user. The contents of this database are not managed by the SWITCH edu-ID Identity Provider. Some external entities can access to the shared attributes database via an API, and set or delete attribute values for selected edu-ID users. When a user accesses to a service provider the shared attribute for that user is added to the standard attributes and sent to the service.
What effectively happens with shared attributes is that one part of AM (the part that is common to a group of services) is extracted from the services and centralized
First application: National Licences
The first application to use shared attributes is the National Licenses service. In the context of the national licenses some publishers grant access to users who satisfy a complex access rule. The user has to be a Swiss citizen, has to accept specific terms, must have been active during the last year and must not be blocked due to service abuse.
A specially developed national licenses service registration platform checks if a user meets all the requirements of a user. If the user does meet the requirements, the flag national-license-compliant is set in the shared attributes database for that user. Consequently, services participating in the national licenses program get the additional attribute and grant access to licensed publications.
If a user does not meet all requirements, the national-license-compliant flag is removed. The user gets an explanation on the registration service and some indications how he or she could re-gain access to the national licenses program.
Note: The shared attributes service has been developed by SWITCH to solve a specific problem and to gain experiences with the concept. It is possible that the service will be replaced in the future by a more general group management service.