I'm learning wireless. The following command works great:

aircrack-ng -w mywordlist <capture file>

If I generate the wordlist on the fly by JTR, for instance, then I need to provide -e :

root@kali:~/spielordner/wifu# john --wordlist=./wordlist.1 --rules=TestTest --stdout | aircrack-ng -w - mycapture 
Please specify an ESSID or BSSID.

When I send the passwords John creates into a file and provide that file to aircrack-ng's -w parameter then I don't need -e. Where's the structural difference between those 2 modes?


In most recent versions of Aircrack-ng, when you use the command:
aircrack-ng -w mywordlist <capture file>

You'll be asked to enter the index number of the target network.check this image

Basically, both tools need the SSID to be able to crack the 4-way handshake 'not the point to discuss', but the difference is within the tool.

I believe that Aircrack-ng has some advanced interpreting methods to discover the required bssid or essid from the file, while JTR just asks you to enter it manually.

  • A follow up problem is that when I enter the second command with bssid it complains that one doesn't exist (which it definitely does). But I first wanted to clarify the above point. – kaidentity Sep 20 '16 at 8:10
  • I'm not familiar with JTR to help you with this, but if you have problems with JTR, just use another tools. Crunch for example will help you in same way. – Emadeddin Sep 20 '16 at 8:13
  • JTR is not the problem the error message comes from aircrack-ng... – kaidentity Sep 20 '16 at 8:15
  • Edit your question, update it with some examples. – Emadeddin Sep 20 '16 at 8:18

From www.aircrack-ng.org

The techniques and the approach above do not work for WPA/WPA2 pre-shared keys. The only way to crack these pre-shared keys is via a dictionary attack. This capability is also included in aircrack-ng.

With pre-shared keys, the client and access point establish keying material to be used for their communication at the outset, when the client first associates with the access point. There is a four-way handshake between the client and access point. airodump-ng can capture this four-way handshake. Using input from a provided word list (dictionary), aircrack-ng duplicates the four-way handshake to determine if a particular entry in the word list matches the results the four-way handshake. If it does, then the pre-shared key has been successfully identified.

  • Obviously you have never heard that you can create your own dictionary files which is basically what I'm doing above, in 2 different flavors. What you quote refers to the statistical analysis methods used to crack WEP. They don't work for WPA/WPA2, but this is not the point here... – kaidentity Sep 20 '16 at 6:37

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