void
    silc_client_perform_key_agreement(SilcClient client,
                                      SilcClientConnection conn,
                                      SilcClientEntry client_entry,
                                      SilcClientConnectionParams *params,
                                      SilcPublicKey public_key,
                                      SilcPrivateKey private_key,
                                      char *hostname, int port,
                                      SilcKeyAgreementCallback completion,
                                      void *context);

    Performs the key agreement protocol.  Application may use this to
    initiate the key agreement protocol.  Usually this is called after
    receiving the `key_agreement' client operation.

    The `hostname' is the remote hostname (or IP address) and the `port'
    is the remote port.  The `completion' callback with the `context' will
    be called after the key agreement protocol.

    The `params' is connection parameters and it may be used to define
    the key agreement connection related parameters.  It may be NULL.