mysql_ssl_set: parameter for key

[Tilman Glötzner]

Hello

mysql_ssl_set takes the key, a certificate for the key (I guess it is the certificate for the corresponding public key), and the (trusted) certificate of a certifying authority as parameters among others.

To establish an SSL connection (from a client), only the trusted certifcate is needed -- which is understandable, as the session key is negotated as part of the initial handshake.

What is is purpose of the key and and its certificate ? Are these parameters only needed to setup the server end of an SSL connection ?

Thanks
Tilman