wpa_supplicant fails with ndiswrapper andmadwifi driver for Atheros 802.11a/b/g card

Jouni Malinen jkmaline at cc.hut.fi
Sun Nov 28 02:40:30 EST 2004


On Sun, Nov 21, 2004 at 07:59:01PM -0800, Michael Reilly wrote:

> I just tried 0.12rc3 with my two Atheros cards against a Cisco 1100 AP 
> using WPA-PSK.  It failed with both cards.  It may be related to the timing 
> related problems you are seeing.  I have been busy at work so haven't had a 
> chance to play with this a lot

Could you please re-test ndiswrapper with the current development branch
snapshot of wpa_supplicant?

I did some more testing with number of different client cards, drivers,
and APs. There are indeed quite many cases where the group key handshake
fails because of the client not receiving the encrypted EAPOL-Key frame.

I was able to improve reliablity of the key handshakes greatly by
removing some of the key clearing operations. In practice, this removed
the five key delete operations that were done immediately after link up
(association) event.

I don't know why removing keys would cause issues in receiving encrypted
unicast frames _after_ new PTK is configured just some time after this.
Anyway, most of the key clearing operations are not really needed, so
getting rid of them should at least speed up association a bit, if
nothing else. I would like to remove the unicast key for the new AP to
make sure that no old key is configured during the initial 4-Way
Handshake. However, even that one operation seemed to make group key
handshake unreliable.

-- 
Jouni Malinen                                            PGP id EFC895FA



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