SilcBool silc_id_id2str(const void *id, SilcIdType type,
                            unsigned char *ret_id, SilcUInt32 ret_id_size,
                            SilcUInt32 *ret_id_len);

    Converts an ID of type `type' to data. This can be used to
    convert the ID's to data for inclusion in the packets.  This does
    not allocate any memory.