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wpa_capture [2009/09/19 04:09] – "is using is using" changed to "is using" mister_xwpa_capture [2014/09/05 02:50] – Fixed typo mister_x
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 ====== Tutorial: WPA Packet Capture Explained ====== ====== Tutorial: WPA Packet Capture Explained ======
-Version: 1.04 January 262007\\+Version: 1.05 December 152009\\
 By: darkAudax By: darkAudax
  
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 Notice that the AP initiates the four-way handshake by sending the first packet.  The first pair of packets has a "replay counter" value of 1.  The second pair has a "replay counter" value of 2.  Packets with the same "replay counter" value are matching sets.  If you have only one packet for a specific "replay counter" value then you are missing it from the capture and packet you do have cannot be used by aircrack-ng.  That is why sometimes you have four EAPOL packets in your capture but aircrack-ng still says there are "0" handshakes.  You must have matching pairs. Notice that the AP initiates the four-way handshake by sending the first packet.  The first pair of packets has a "replay counter" value of 1.  The second pair has a "replay counter" value of 2.  Packets with the same "replay counter" value are matching sets.  If you have only one packet for a specific "replay counter" value then you are missing it from the capture and packet you do have cannot be used by aircrack-ng.  That is why sometimes you have four EAPOL packets in your capture but aircrack-ng still says there are "0" handshakes.  You must have matching pairs.
 +
 +There are some other items to point out if you are analyzing a capture looking for a valid capture.  EAPOL packets 1 and 3 should have the same nonce value.  If they don't, then they are not part of the matching set.  Aircrack-ng also requires a valid beacon.  Ensure this beacon is part of the same packet sequence numbers.  For example, if the beacon packet sequence number is higher then the EAPOL packet sequence numbers from the AP, the handshake will be ignored.  This is because the aircrack-ng "resets" handshake sets when association packets and similar are seen.
  
 IEEE 802.11 -> Frame Control -> Flags -> DS Status Flag: The direction flags show "FROM DS" or "TO DS" depending on the packet.  Meaning coming from the AP or going to it. IEEE 802.11 -> Frame Control -> Flags -> DS Status Flag: The direction flags show "FROM DS" or "TO DS" depending on the packet.  Meaning coming from the AP or going to it.
wpa_capture.txt · Last modified: 2018/10/06 02:54 by mister_x