Generate a bulk encryption key. The algorithm and key size have previously been specified via the CPSetKeyParam Schannel Extensions function.
Note that the initialization vector (IV) is typically set in the usual way (via CPSetKeyParam (KP_IV)). Some protocol and cipher suite combinations, however, insist on building the IV from the key block. In this case, the CSP should derive the IV automatically.
If SSL 2 is being used, then this key is also used as the MAC key.