Role-Based Access Control

Role-Based Access Control (RBAC) will be used by ORBIT to control each user's access to ORBIT resources based on his or her role. RBAC promises simpler administration of access control than maintaining access control lists for each resource. It enables an organization to enforce separation of duty, the principle of least privilege and timely revocation of trust. Because it is based on a formal model, a given assignment of users to roles may be checked for consistency with the organization's security goals.

RBAC is being implemented in ORBIT to protect each project's information from access or disruption by other projects, to minimize some problems within projects, and to provide tools for project administration by each project's Principal Investigator. That is, to insure that an ORBIT user has access only to information that belongs to the project he or she is working on, and is granted permissions in accord with the roles in which he or she is active.

To explain RBAC's use of roles, first some terminology. In normal, scheduled operation, ORBIT is designed to insure that each person using an ORBIT resource is allowed to do so at that time. The Lightweight Directory Access Protocol (LDAP) is used by ORBIT to authenticate each user by checking his or her password when he or she logs into an ORBIT controller or server. LDAP authentication and the proper use of ORBIT user id's and passwords allows each user id to be related to a single human user, although a single person may have one or more ORBIT user id's. Each ORBIT user id may be logged into one or more sessions, and during each session there may well be multiple computer processes initiated by the user. A process is an instance of a user running an application program like a spreadsheet, editor or browser.

When a user runs an application program that process acts on behalf of the user and is referred to as a subject. An object is any resource accessible on a computer system, including peripherals, files, databases, and fields in a database. ORBIT objects include the grid, sandboxes, ORBIT databases, and noise generator. An operation is an active part of a process invoked by the subject process much like a function call or a method invocation. In general, a permission or privilege is the authorization to perform some action on the system. In RBAC, a permission is the authorization to perform a given operation on a given object.

The use of roles to control access is based on the observation that there may be thousands of users in a given organization, but there are fewer than a hundred different roles they act in at any given time to access resources. Users are assigned to one or more roles. Each role has a defined set of permissions, each permission either allowing or disallowing an operation invoked by a subject process run by a user active in that role to be performed on a given object.

In ORBIT, role-based access control will be implemented using LDAP. Besides authenticating users, an LDAP schema will be developed for a directory of projects and roles. In ORBIT roles will be expressed within projects. A given user may be assigned one set of roles on a given project and a different set on another project.

Development of ORBIT RBAC will require modifications to the services that manage ORBIT resources so that access to the methods those services present to users can be controlled. Further, a monitor program based on the NIST RBAC/Web code is needed to keep track of each user's active roles and to grant access quickly to users when accessing these methods. It is expected that this implementation will have acceptable performance while providing the desired levels of protection and administrative capability.

The rest of the wiki pages for the ORBIT Role-Based Access Control project are organized as follows. The RBAC Reference Model page briefly describes the core, hierarchical, static separation of duty and dynamic separation of duty components of the RBAC specification. The ORBIT RBAC Design page and its subsidiary pages contain design issues and decisions. The LDAP Resources and RBAC Resources pages each briefly describe important sources then give a fairly comprehensive list of references. All of the bracketed wiki references like Ame04 are on the RBAC Resources page.

Last modified 18 years ago Last modified on Oct 10, 2006, 2:11:07 PM
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