bool
    silc_client_send_private_message_key_request(SilcClient client,
                                               SilcClientConnection conn,
                                               SilcClientEntry client_entry);

    This function can be used to send an private message key indicator
    request to the remote client indicated by 'client_entry'.  This can
    be used when setting a static or pre-shared private message key.
    The sender of this packet is the initiator and must set the 'responder'
    argument in silc_client_add_private_message_key function to FALSE.
    The receiver of this indicator request must set it to TRUE, if the
    receiver decides to set a private message key.  By using this
    function applications may automate initiator/responder setting in
    private message key functions, without asking from user which one is
    the initiator and which one is responder.

    The sender of this packet must set the private message key for
    'client_entry' before calling this function.  The 'responder'
    argument MUST be set to FALSE when setting the key.