GNOME Bugzilla – Bug 327073
Handle shared WEP key magic for Atheros cards
Last modified: 2006-11-27 16:19:36 UTC
It just took me a day to rediscover the following magic to make Atheros cards work in WEP restricted mode: "If your AP is configured to have WEP enabled and is in restricted mode (rather then open mode) the madwifi driver won't properly associate. Symptoms of this include iwconfig showing the NIC associating and unassociating on a regular basis and not being able to send any traffic. The solution is to force the authentication to restricted mode using iwpriv in addition to iwconfig. The following commands should do the trick: iwconfig ath0 key restricted iwpriv ath0 authmode 2" This affects Thinkpads, which are otherwise among the most well behaved laptops for Linux, as well as many other laptops and external adapters. It would be fantastic if Linux would take care of this automatically. Apparently Windows does. Is NetworkManager the right place? Authentication modes for madwifi: * iwpriv ath0 authmode 1 (open key authentication [default]) * iwpriv ath0 authmode 2 (shared key identification) * iwpriv ath0 authmode 3 (802.1x authentication)
I've done a tiny bit of homework since reporting this. 1) "Shared key" seems to be the common term for restricted mode. 2) "Shared key" is insecure and not recommended. Nevertheless, you may visit a place which uses it, like I did. 3) In Windows, you apparently select explicitly between "open", "shared" and "wpa". So I'm not sure doing it automatically is feasible. But making it more obvious how to do it, and abstracting out driver differences, would be very useful.
Yeah, having documentation here would probably be useful if nothing else...
This should get handled by the madwifi driver internally, by recognizing the Wireless Extensions option for shared key like every other driver... IW_ENCODE_OPEN - Open System mode IW_ENCODE_RESTRICTED - Shared Key mode madwifi currently doesn't do this. These values were originally intended to do other things but over the years have come to mean the auth mode settings instead.