WPA-PSK on Thinkpad T40

Stephen Bosch posting
Tue Dec 15 23:57:28 PST 2009

Hi, Brian, thanks for the reply.

My comments below:

On Wed, Dec 16, 2009 at 4:33 AM, Brian Bender <d6p0d8f02 at sneakemail.com> wrote:
> On Tue, Dec 15, 2009 at 7:35 PM, Stephen Bosch posting-at-vodacomm.ca
> |hostaplist/Allow to me| <ap7zwsp4mt at sneakemail.com> wrote:
>> The problem is that my psk is 26 characters, and this works with other
>> operating systems, so I don't understand why wpa_supplicant should be
>> rejecting it.
> Your network's passphrase is a string that just happens to look like a
> hex number. It's still just a string to the algorithm that uses it --
> are you sure you entered it correctly? It's a _case-sensitive_ string,
> for one thing...

Well, I entered it, exactly as I have it on record, in Windows, where
it works, or you wouldn't be reading this message :)

I have tried it, in quotation marks, in exactly that form.
wpa_supplicant accepts it, but the handshake fails. Perhaps the
problem is not in the PSK, but the output doesn't provide an obvious
(at least, to me) clue. At any rate, it fails with the classic error

"WPA: 4-Way Handshake failed - pre-shared key may be incorrect"

The form in my example is with lowercase letters, which was an
experiment to see if that would make any difference. I have not tested
it with quotation marks yet.

> The psk for WPA-PSK is either (A) calculated from the network's SSID
> and a passphrase (string) of 8 to 63 characters, or (B) entered
> directly as a 64-character hex value. That's part of the WPA spec. The
> other operating systems' user interfaces may not require quotes around
> it, but they're still using that 26-char string as a passphrase,
> because at that length that's all it can be.

This makes sense. I have converted the hex to ASCII and come up with
an intelligible passphrase, but it contains non-Latin-1 characters,
and as yet I have found no way to produce the required characters on
the console. I'm open to suggestions.

> You can see what the actual psk is by passing your SSID and passphrase
> to the wpa_passphrase utility that's part of the hostap package. The
> output is even in the right format for your wpa_supplicant.conf

I will give that a try, and promise to post again if any of these
things work. Until then, I'm all ears for more ideas.



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