Secure Login based on SSL Server Socket.

这是一个开源的项目，opennssl。对学习ssl非常有帮助-The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, full-featured, and Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer

modify request header

VPN通过一个私有的通道来创建一个安全的私有连接，将远程用户、公司分支机构、公司的业务伙伴等跟企业网连接起来，形成一个扩展的公司企业网(VPN creates a secure private connection through a private channel, connecting the remote user, the company branch, and the business partner of the company with the enterprise network