FW: [wpa_supplicant] Most WPA AP:s dont get to WPA_4WAY_HANDSHAKE state when wrong PSK is supplied

[Olsson, Ola1]

Thanks for the answer Paul,

I am not actually not sure, i have not yet been able to get the sniffer logs from the scenario but from the supplicant logs I get into driver_wext_event_wireless SIOCGIWAP. Here, there are two ways for the code to go, either to send an EVENT_ASSOCIATE or and EVENT_DISASSOC. Everytime the wrong psk is given, we end up in EVENT_DISASSOC because the is_zero_ether_addr() is true, otherwise we end up in EVENT_ASSOC.

Are there any other explanations than that of the PSK being wrong?

Thanks in advance.




-----Original Message-----
From: Paul Stewart [mailto:pstew at google.com] 
Sent: fredag den 10 december 2010 15:57
To: Olsson, Ola1
Cc: Jouni Malinen; hostap at lists.shmoo.com
Subject: Re: FW: [wpa_supplicant] Most WPA AP:s dont get to WPA_4WAY_HANDSHAKE state when wrong PSK is supplied

On Sun, Dec 5, 2010 at 12:46 AM, Olsson, Ola1
<Ola1.Olsson at sonyericsson.com> wrote:
> Hi,
>
> Sorry for bad explanation.
> My problems only exist when typing the wrong PSK, when typing the correct PSK, everything works fine.
>
> The only way for upper layers on Android to know that the PSK is wrong is when the warning "pre-shared key may be incorrect" is printed.
> For some AP:s I will get to the 4-way handshake before I get the disconnect event, and in this case, everything is also fine. But, a lot of AP:s will just trigger disassociate when we are in associate-state and as we all know, we wont get the string printed in that case.
>
> Have you seen this behaviour?

I have not.  How was the AP able to determine you had a bad passphrase
when you were in the "associate" state?  At this point the STA hasn't
sent any keying material that could indicate one oway or another what
PSK it has been configured with.


> Do you know any side effects of trigger the print when getting EVENT_DISASSOC in associating state? That will solve my problem at least.
>
> Best regards, Ola
>
>
> -----Original Message-----
> From: hostap-bounces at lists.shmoo.com [mailto:hostap-bounces at lists.shmoo.com] On Behalf Of Jouni Malinen
> Sent: lördag den 4 december 2010 20:53
> To: hostap at lists.shmoo.com
> Subject: Re: FW: [wpa_supplicant] Most WPA AP:s dont get to WPA_4WAY_HANDSHAKE state when wrong PSK is supplied
>
> On Sat, Dec 04, 2010 at 12:50:23PM +0100, Olsson, Ola1 wrote:
>> The behaviour I get in most cases is that I get my phone in state ASSOCIATING and then get EVENT_DISASSOC from wpa_driver_wext_event_wireless() in driver_wext.c after evaluating that the is_zero_ether_addr() evaluates to true.
>>
>> My question is:
>> *Why don't we treat this 00:00:00:00:00:00 mac address as erroneous PSK even though we are only in ASSOCIATING state? When changing the code in events.c to also send the callback when in ASSOCIATING, it works perfectly. I'm a little bit worried of the side effects though. Anybody who knows what might go wrong?
>
> I'm not sure I fully understood your description, but if you are saying
> that you get disconnected even before association, there is no way of
> knowing whether the PSK was correct or not. That warning is only shown
> if the connection attempt fails during 4-way handshake. ASSOCIATING
> state should only be used before 4-way handshake.
>
> --
> Jouni Malinen                                            PGP id EFC895FA
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