[security-dev] Meaningful relationships

No, not that kind. I'm currently reviewing the database schema for the identity management module - in the previous version of PicketLink we had quite a good design [1] that was a little abstract, but met all the requirements well. Here's a summary of the key tables: IdentityObject - this table would contain both User and Group records IdentityObjectRelationship - models the relationship between User and Group, i.e. Group memberships IdentityObjectRelationshipName - this table is a special one that contained the names for "named relationships". A named relationship can effectively be thought of as a Role, (and was also modelled in the IdentityObjectRelationship table) for example "John" (User) is a "Manager" (Role, the "named" bit of the relationship) in "Head Office" (Group) - see [2] for more details. With the introduction of application roles we need to jig this design a little bit. I was thinking of keeping IdentityObject essentially the same, with the exception that it would also be used to contain Roles, as well as Users and Groups. Instead of the IdentityObjectRelationship table though, I propose we go with the following slightly less abstract design: IdentityMembership ------------------------- MEMBER GROUP ROLE This basically allows us to make any IdentityType (User, Group or Role) a member of a Group or Role, or both. Here's a few scenarios: 1. John is a part of the accounting group. IdentityMembership ------------------------- MEMBER = John (User) GROUP = accounting ROLE = null 2. The Manager group is a subgroup of the Employee group. IdentityMembership ------------------------- MEMBER = Manager (Group) GROUP = Employee ROLE = null 3. Kevin is an administrator for the Manager group IdentityMembership ------------------------- MEMBER = Kevin (User) GROUP = Manager ROLE = Admin 4. Kelly is a superuser (which is an application role) IdentityMembership ------------------------- MEMBER = Kelly (User) GROUP = null ROLE = Superuser With the above examples in mind, this now leads into the "meaningful relationships" theme - can anyone think of any other meaningful security relationships that cannot be modelled with this design? I'm not really looking to make the design "future proof" as such, but I would like to ensure we cover all currently known scenarios / use cases. Comments and feedback welcome of course. [1] http://anonsvn.jboss.org/repos/picketlink/idm/downloads/docs/1.0.0.GA/Ref... [2] http://anonsvn.jboss.org/repos/picketlink/idm/downloads/docs/1.0.0.GA/Ref...