WPA: Group Key Handshake Error

[Fan Zhang]

Hi All,

I am developing the madwifi based on AR5212 cards, madwifi-ng, Ubuntu 10.04
32-bit with the kernel (2.6.32).
I want to randomly change MAC addresses of a client when it communicates
with an AP.

Now the problem is that Group Key Handshake can not be completed because of
"EAPOL-Key timeout".
I use not only the wireshark to sniff the channel, but also madwifi
debugging.


The two handshakes of WAP-PSK is OK. The pairwise key handshake completed
(WPA).
Then for the AP, it sent a 1/2 msg of Group Key Handshake. The client
received correctly.
After that, the client set a TKIP key and sent a response to AP. The msg is
about EAPOL key information. I think the msg is right.
But on the AP side, AP received the msg with different contents. The detail
is bellow.


Sending by client  (wireshark on the client side)
Azurewav_62:ed:d1  ----> 06:20:a6:54:68:46   EAPOL  Key


Received by ap (wireshark on the ap side)
Azurewav_62:ed:d1 -----> 06:20:a6:54:68:46  LLC  I P, N(R)=91, N(S)=125;
DSAP 0xc6 Group, SSAP ox92 Command