-1
Say I have sniffed on a Wi-Fi, and I have happened to have found the 64 WEP-Key. What can I do with this? Can I reverse the RC4 and use that as a password. Do I need to include the IV? I don't understand if the key is a password or something else.
note. This is not so I can go around cracking peoples Wi-Fi. This question is for educational purposes only.
an earwig
Posted 2014-04-04T13:49:24.673
Reputation: 255
3
User entered WEP keys are 40 or 104 bits. Combined with a per-packet 24-bit IV, they become a 64- or 128-bit key for RC4.
You can't find the key just by sniffing (that would be exceedingly lame). You have to do some offline brute forcing on the shared key authentication values, or some other automated cryptanalysis of weak IV packets, to recover the WEP key.
Once you have the WEP key, you can use it directly to join the network, or feed it to Wireshark to decode all the packets you've captured.
Spiff
Posted 2014-04-04T13:49:24.673
Reputation: 84 656
Why The Downvote :( – an earwig – 2014-04-04T13:53:11.903
The key is the key is the key. You can use this directly to connect to the network. Passphrases actually just get transformed to this kind of thingy. The input dialog of your OS for network configuration should distinguish a key from a passphrase automatically, so you can use it. You might try to read this for educational purposes.
– Andreas Wiese – 2014-04-04T13:53:13.213