A network access control approach based on the AAA architecture and authorization attributes

摘要

Network access control mechanisms constitute an increasingly needed service, when communications are becoming more and more ubiquitous thanks to some technologies such as wireless networks or Mobile IP. This paper presents a particular scenario where access rules are based not only on the identity of the different users but also on authorization data related to those users. In order to accomplish this general goal, it will be necessary to add to the traditional system-specific services for authentication and authorization, and also some entities able to manage the information related to identity, roles and permissions. Network access will be based on the 802. 1X framework and the Authentication, Authorization, and Accounting (AAA) architecture, as they constitute the basis for most of the existing proposals for limiting the access to a restricted network. These proposals will be extended making use of an authorization infrastructure based on SAML statements, the RBAC model, and XACML as the main language for expressing authorization policies. The solution that we present in this paper is a consequence of an exhaustive and non-trivial analysis of the different mechanisms that could be used to provide this kind of service. As we will see, the correct integration of these different mechanisms leads to the definition of a scalable and versatile network access control system which conforms to the guidelines outlined by the AAA initiative.