The Development And Research Of Open VPN Customization System Based On Engine Mechanism

Rapidly developing of computer communication technology and the birth of various network attack means make people gradually realized the importance of the communication security. With more and more companies using VPN technology to do the task expanding, the VPN technology based on IPSec agreement cannot meet the market demand and it exposes all sorts of drawbacks such as the complex method of configure,the conflict with NAT equipment when be used and bring potential safety hazard to the operating system.So the VPN technology based on SSL agreement comes out.The OpenVPN technology found lately is the upgrade version of the VPN,include a series of code library in SSLeay using plaintext encryption to ensure the security of communication.The length of key is proportional to the intensity of security in general.But the international security center limit password products which lead to the key created by standard SSL agreement is short. And its security is so low that could not be used in the field such as government and big enterprise which require higher security.At the same time, the kind of algorithms in the SSLeay library is limited which cannot apply for same special occasions.This article adds two high security of encryption algorithms to the system bases on the function mechanism of the Engine. And design the OQ interface to create a set of stable and efficient VPN security network communication system.To solve above problems,the thesis mainly studied from the following four aspects:1) OpenVPN communication process include platform construction and handshake Authentication.Especially explain the creation process of the virtual channel GUI in detail.2) Add new encryption algorithm by establishing Engine mechanism.Introduce the working process of Engine mechanism,including the analysis of its data structure packaging format.In addition,introduce the TWOFISH and ZUC briefly.3) Put Engine library which include new algorithm into OpenSSL and OpenVPN system to do test.By this way to determine whether the new algorithm has been successfully added.4) Introduce QT technology in brief and explain the function of each part in QT interface.Then make the whole system for visualization by the background script link.