Getting wrong value for MIC - how to debug?

Jouni Malinen j
Tue Jan 31 11:35:59 PST 2012

On Mon, Jan 30, 2012 at 10:22:35PM -0800, Chris Phoenix wrote:
> And I'm getting the wrong value. That is, I'm getting a different
> value than the original MIC. Obviously, stock wpa_supplicant code
> isn't broken. But my MIC-regenerating code is simple. So what's my
> next step? (Yes, the MIC computed on my Mac version of wpa_supplicant
> for my device's packets is the same as the one I computed in my
> embedded device.)

What kind of CPU do you have on the embedded device? Did you modify
anything in the crypto implementation? Are you using the internal crypto
implementation or an external TLS/crypto library?

As far as your test code is concerned, it seems to be defining PMK to be
"password" which is not correct. That would be the passphrase and you
would need to run it through pbkdf2_sha1() to generate the PMK.

Jouni Malinen                                            PGP id EFC895FA

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