VPN Research And Implementation Of IPSec On Linux

At present, with the development of Internet, Security of network is becoming more and more important. Currently, how to realize safe ,convenient, instant transportation of information and data on Internet is one of the newest content we have to consider. The Internet is subject to many threats, including loss of privacy data, changed illegally, loss of data integrity and identity. But, IP Security protocol have many merits about Internet Security, IPSec is IP security standard proposed by IETF, which keyed and authenticated IP packet when packet flow through IP level, making security service independenting with all kinds of application program. Building VPN using IPSec is convenient and plexible, more and more attention is paid to IPSec VPN.In the paper, according to development of computer security and request of user, I carefully study the IPSec VPN on linux kernel, including IPSec protocol, Internet key exchange protocol, data encryption ,algorithm and so on. And considering IPsec protocol simplification, All modules and its interface of open source code of Linux are analysed, including FreesWan software, based on which describing functional modules of IPSec VPN. These modules are IPSec kernel, IKE and PFKEY module. The IPSec kernel module runs in the Linux kernel with high efficiency to accomplish IP packages' deal, such as authentication and encryption. The IKE module is used to make SA for data, which runs in the user space ,The PFKEY module' s function is to accomplish the former two modules' communication. And finally realize an IPSecVPN instance and complete GUI configure .