SilcBool silc_packet_set_ids(SilcPacketStream stream,
                                 SilcIdType src_id_type, const void *src_id
                                 SilcIdType dst_id_type, const void *dst_id);

    Set the source ID and destination ID to be used when sending packets to
    this packet stream.  The IDs to be used for a packet stream can be
    overridden when sending packets.  However, if the IDs do not ever change
    for the packet stream it is recommended they are set using this function.
    In this case they can be omitted when sending packets to the stream.
    It is also possible to set only source or destination ID.