Improvement of XACML access control mechanism based on NETCONF subtree filtering rpc

The Network Configuration Protocol (NETCONF) is a new network Management Protocol which becomes more and more widely used in network management area. To make NETCONF much safer, we extend the extensible Access Control Markup Language(XACML) access control mechanism and implement it on our NETCONF network management system-BUPT-NEP. We use subtree filtering expression to represent resource instead of xpath expression, which makes the new mechanism suitable for access control on NETCONF subtree filtering rpc.