On Tue, May 09, 2017 at 02:16:31PM -0400, Michael Skeffington wrote: > In order to allow wpa_supplicant to correctly identify a perceived WPA TKIP > key > recovery attack the michael MIC must be checked before the packet decode is > attempted. A packet with an invalid MIC will always fail a decrypt check > which > previously was being checked first. Therefore the MIC failure bit of > status flags > describing the error would remain unset.
Which driver and WLAN hardware are you using? Michael MIC is encrypted, so to be able to check that, the frame will obviously need to be decrypted first. If that WEP decryption fails, this frame needs to be dropped without indicating Michael MIC failure. WEP part here is completely independent of Michael MIC. It is possible that there is a driver that handles these steps in hardware/firmware and if so, that driver may have a bug if you do not see Michael MIC failures reported correctly. Anyway, as Johannes pointed out, this part in mac80211 is in the correct sequence and that cannot be changed since it would completely break TKIP for more or less all software-based cases. -- Jouni Malinen PGP id EFC895FA
