Cryptographic Protocols - Codes: The Guide to Secrecy from Ancient to Modern Times - page 224

3. If the server is not using anonymous DiKe-Hellman, it may send a request
for the client's certificate. Contained in the client certificate request is a
certificate type that dictates the PKC to be employed. For instance, if
either RSA or DSS is used with authenticated DiKe-Hellman, then au-
thentication (only) is accomplished via an RSA or DSS signature on the
certificate.
4. The server sends a server-hello-done message.
III Key Exchange and Client Authentication :
1. After receiving the server-hello-done message, the client verifies the server's
certificate if sent, and other server-hello parameters. If all is valid, the
client responds.
2. If requested, the client sends a certificate. If authenticated DiKe-Hellman
is being used, then the client's public-keyparameters are included.
3. The client-key-exchange message must now be sent. The key-exchange mode
dictates the content as follows:
(i) If RSA is used, then the client generates a 48-byte premaster secret ,
which is encrypted with the server's public key (sent with certificate
in Stage I).
(ii) If anonymous DiKe-Hellman is employed, then the client's public
DiKe-Hellman parameters are sent.
(iii) If authenticated DiKe-Hellman is used, then the parameters were
alreadysent in step 1 of stage II, so this is a null action.
(iv) If Fortezza is used, then the client's Fortezza parameters are sent.
3. If a certificate has been requested, the client signs a piece of data that is
unique to the handshake and known byboth client and server, along with
the encrypted premaster secret.
IV FinishProtocol :
To simplifythe final stage, we assume that RSA is being used.
1. If the server verifies the client's identity, then the server uses its private key
to decipher the premaster secret. Then the server performs a sequence of
steps to create the master secret from the premaster secret, a one-time
48-byte generated for this session. These same steps are followed by the
client to recover the master secret.
2. Both the client and the server use the master secret to generate session
keys, which are symmetric keys used to encipher and decipher information
exchanged over the course of this SSL session, and to verifyits integrity ,
meaning the detection of changes that might have occurred in the time
period from transmission to reception.