Configuring Ssl; Overview; Ssl Security Mechanism; Ssl Protocol Stack - HP 5920 Series Configuration Manual

Configuring SSL

Overview

Secure Sockets Layer (SSL) is a cryptographic protocol that provides communication security for
TCP-based application layer protocols such as HTTP. SSL has been widely used in applications such as
e-business and online banking to provide secure data transmission over the Internet.

SSL security mechanism

SSL provides the following security services:
Privacy—SSL uses a symmetric encryption algorithm to encrypt data and uses an asymmetric key
•
algorithm such as RSA to encrypt the key used by the symmetric encryption algorithm. For more
information about RSA, see
Authentication—SSL uses certificate-based digital signatures to authenticate the SSL server and
•
client. The SSL server and client obtain digital certificates through PKI. For more information about
PKI and digital certificates, see "Configuring PKI."
• Integrity—SSL uses the message authentication code (MAC) to verify message integrity. It uses a
MAC algorithm and a key to transform a message of any length to a fixed-length message. Any
change to the original message will result in a change to the calculated fixed-length message. As
shown in
The sender uses a MAC algorithm and a key to calculate a MAC value for a message,
a.
appends the MAC value to the message, and sends the message to the receiver.
The receiver uses the same key and MAC algorithm to calculate a MAC value for the received
b.
message, and compares it with the MAC value appended to the message.
If the two MAC values are the same, the receiver considers the message intact. Otherwise, the
c.
receiver considers that the message has been tampered and discards the message.
Figure 61 MAC algorithm diagram

SSL protocol stack

SSL comprises an SSL record protocol at the lower layer, and an SSL handshake protocol, SSL change
cipher spec protocol, and SSL alert protocol at the upper layer.
"Managing public
Figure 61, the message integrity verification process is as follows:
keys."
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