void
    silc_client_perform_key_agreement_stream(
                                      SilcClient client,
                                      SilcClientConnection conn,
                                      SilcClientEntry client_entry,
                                      SilcClientConnectionParams *params,
                                      SilcPublicKey public_key,
                                      SilcPrivateKey private_key,
                                      SilcStream stream,
                                      SilcKeyAgreementCallback completion,
                                      void *context);

    Same as silc_client_perform_key_agreement but the caller has created
    the connection to remote client.  The `stream' is the created
    connection.