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<TITLE>Forcing MIC failures, again</TITLE>
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<P><FONT SIZE=2 FACE="Arial">Hi guys,</FONT>
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<P><FONT SIZE=2 FACE="Arial">I've got Ubuntu with a 2.6.20 kernel now and I'm looking through what my options are for forcing MIC failures. I've got a zd1211rw driver working with ieee80211 driver. I still don't really understand the difference between ieee80211 and mac80211 but as far as I can tell they do the same thing in a slightly different way?</FONT></P>
<P><FONT SIZE=2 FACE="Arial">My mac80211 doesn't work yet, probably not part of the kernel so I'll leave the original advice I got from Jouni for the next stage when I have my zd1211rw working with mac80211.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Anyway right now I can rebuild the ieee80211_crypt_tkip module with some code to corrupt the MIC but it doesn't seem to have any effect. I added something like this:</FONT></P>
<P><FONT SIZE=2 FACE="Arial">if (corruptCondition)</FONT>
<BR><FONT SIZE=2 FACE="Arial"> pos[0]++;</FONT>
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<P><FONT SIZE=2 FACE="Arial">at the end of the function ieee80211_michael_mic_add, just before the return 0 statement. I added some printks to make sure my code executes when I do some repeated pinging and it does get executed</FONT></P>
<P><FONT SIZE=2 FACE="Arial">I also tried some printk to print out the 8 bytes at the "pos" pointer but they don't match what I see in my sniffer.</FONT>
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<P><FONT SIZE=2 FACE="Arial">Questions:</FONT>
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<P><FONT SIZE=2 FACE="Arial">- Would the contents of pos match the bytes in the sniffer or is there another level of encryption that happens?</FONT>
<BR><FONT SIZE=2 FACE="Arial">- Why doesn't the change to the MIC cause a MIC failure on the AP? Do I have the code in the wrong spot?</FONT>
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<P><FONT SIZE=2 FACE="Arial">Thanks,</FONT>
<BR><FONT SIZE=2 FACE="Arial">Andrew</FONT>
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