关于PKI(公钥基础设施)的介绍，CA的介绍，CA如何管理证书，以及证书在网络中的使用。对于了解CA,证书有一定的帮助-About the introduction of the PKI (public key infrastructure), the introduction of CA, CA How management certificate, as well as the use of the certificate in the network. Understanding the CA certificate has some help