WE-18 questions

Jouni Malinen jkmaline at cc.hut.fi
Mon Aug 23 23:54:05 EDT 2004


On Thu, Aug 19, 2004 at 04:25:44AM +0100, Pedro Ramalhais wrote:

> I have some questions because i can't figure out how to use
> SIOCSIWENCODEEXT IOCTL in WE-18.
> - Where can i put the key_idx in struct iw_encode_ext?

No idea.. I have already forgotten.. ;-)

Based on the comment with struct iw_encode_ext, I would assume the
purpose was to use flags with in struct iw_point. In other words, in LSB
of flags (idx = (flags & IW_ENCODE_INDEX)).

> - Where can i put set_tx (from wpa_supplicant) in struct iw_encode_ext?

Nowhere.. This could be added as a new flag or alternatively, you can
just first configure the key and then use SIOCSIWENCODE with empty data
to set the TX key index.

> - Which one of tx_seq and rx_seq should we use as the seq for:
> (*crypt)->ops->set_key(encext->key, encext->key_len, seq,
> (*crypt)->priv);

seq is for receive, so rx_seq. tx_seq should be zero for set_key. Having
two fields for sequence counters is somewhat unnecessary, because tx_seq
is more or less always zero for set_key and rx_seq is not usually needed
for get_key. The extra field could be used for debugging.

> - What is the use for IW_ENCODE_EXT_TX_SEQ_VALID and
> IW_ENCODE_EXT_RX_SEQ_VALID ?

They indicate whether respective fields should be configured (set_key)
and whether they include valid data (get_key). In other words, one can
set only the rx_seq by using RX_SEQ_VALID flag but leaving out
TX_SEQ_VALID.

> - IW_ENCODE_EXT_GROUP_KEY is used in which situation?

Again, I don't remember.. Looks like it would be set always when struct
iw_encode_ext has addr set to ff:ff:ff:ff:ff:ff. In other words, it
would not really be needed at all..

-- 
Jouni Malinen                                            PGP id EFC895FA



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