Web And Radius-based Access Authentication System For Wireless LAN

The secure operation and management of the WLAN (Wireless Local Area Network ) has become a hotspot recently. Network access control is the basis of networking management. PPPoE authentication, IEEE 802.1x authentication and WEB authentication are the most popular technologies for the access control. According to the characteristic of WLAN, the thesis is concerned with the WEB and RADIUS (Remote Authentication Dial In User Service) based access authentication system for WLAN, aimed at providing satisfactory convenience and maintenance to users.Firstly, the Web-based access authentication system is designed, and the Linux System is chosen as the development environment. After analyzing the principles of netfilter and LKM (Loadable Kernel Module), a kernel-space transparent gateway, which is a key to authentication system, is designed to control users to access the networking resources. The kernel-space gateway is composed of the access control module and DHCP (Dynamic Host Configuration Protocol) server. The difference between the traditional user-space gateway and the kernel-space one is that the latter puts the IP packet handling program in the kernel of Linux system, forwards the packets on the network layer in a real way, thus enhancing the gateway performance. The Web-based access authentication system, consisting of the kernel-space transparent gateway, the Web server and the background database, implements the authentication and accounting of the users.On the basis of the protocol of RADIUS, a RADIUS client program is developped as a function expansion to the system to implement the RADIUS authentication. The RADIUS authentication server, including user information database, provides a solution to user authentication in multiple WLANs.Massive tests indicate that the system offers good stability, expansibility with low cost, therefore meeting the design requirements.