User's Manual

Configuration Guide of XGS-5240-Series
53-1
Chapter 53 SSL Configuration
53.1 Introduction to SSL
As the computer networking technology spreads, the security of the network has b
een taking more and more important impact on the availability and the usability of the
networking application. The network security has become one of the greatest barriers of
modern networking applications.
To protect sensitive data transferred through Web, Netscape introduced the Secure
Socket Layer – SSL protocol, for its Web browser. Up till now, SSL 2.0 and 3.0 has
been released. SSL 2.0 is obsolete because of security problems, and it is not support
ed on the switches of Network. The SSL protocol uses the public-key encryption, and h
as become the industry standard for secure communication on internet for Web browsin
g. The Web browser integrates HTTP and SSL to realize secure communication.
SSL is a safety protocol to protect private data transmission on the Internet. SSL p
rotocols are designed for secure transmission between the client and the server, and a
uthentication both at the server sides and optional client. SSL protocols must build on r
eliable transport layer (such as TCP). SSL protocols are independent for application lay
er. Some protocols such as HTTP, FTP, TELNET and so on, can build on SSL protocol
s transparently. The SSL protocol negotiates for the encryption algorithm, the encryption
key and the server authentication before data is transmitted. Ever since the negotiation
is done, all the data being transferred will be encrypted.
Via above introduction, the security channel is provided by SSL protocols have bel
ow three characteristics:
 Privacy. First they encrypt the suite through negotiation, then all the messages be e
ncrypted.
 Affirmation. Though the client authentication of the conversational is optional, but th
e server is always authenticated.
 Reliability. The message integrality inspect is included in the sending message (use
MAC).
53.1.1 Basic Element of SSL
The basic strategy of SSL provides a safety channel for random application data fo
rwarding between two communication programs. In theory, SSL connect is similar with e
ncrypt TCP connect. The position of SSL protocol is under application layer and on the