Before data can be sent across an SSL connection, the two ends must
negotiate and exchange key information. This is called the
handshake protocol. We won't go into much detail about the
handshake protocol here, because it isn't necessary for
our purposes. For our purposes, you need to know that
the handshake involves the following steps:
- The server sends its certificate to the client and the client
verifies the server certificate.
- The client sends its certificate to the server and
the server verifies the client certificate.
- The client encrypts password information with the server's public key
and sends it to the server. This password information is used by each end of
the connection to generate identical secret keys, which will then be used to
transmit data.
Client authentication (Step 2) is optional: the server can request
that the client provide its certificate, but it is not required to make such
a request. We will be using client authentication in our example.
Now that you have a basic understanding of the infrastructure of
JCA and JSSE under your belt, we can move on to the more active part
of the tutorial: working with a live example.
