WPA, what else

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WPA, what else?
Thomas dOtreppe de Bouvette Aircrack-ng

• UNAM, Mexico City
• November 27-28, 2008

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Agenda

• WEP
• WPA How does it work?
• WPA Practice
• Location, location, location
• Cracking the key
• Bruteforce
• WPA - Tools
• Airbase-ng
• Tkiptun-ng
• Airolib-ng
• Practical stuff

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WEP

• It was fun
• A few new attacks were created
• Caffe Latte
• Cfrag
• PTW2 Now needs less packets needed by PTW to
  crack a key
• WEP Cloaking is now dead too

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• WEP
• WPA How does it work?
• WPA Practice
• Location, location, location
• Cracking the key
• Bruteforce
• WPA - Tools
• Airbase-ng
• Tkiptun-ng
• Airolib-ng
• Practical stuff

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WPA

• More and more networks use WPA
• WPA is a hot topic these days
• CUDA
• New attack and tool tkiptun-ng

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WPA

• 802.11i group launched when flaws were found in
  WEP
• 2 link-layer protocols
• TKIP (WPA1) Draft 3 of 802.11i group (backward
  compatible with legacy hardware).
• CCMP (WPA2) final 802.11i standard
• 2 authentication methods
• Personal PSK
• Enterprise MGT

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WPA-PSK How does it work?
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WPA-PSK 4 way handshake
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WPA-PSK PTK Construction
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WPA-PSK PMK Construction
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• WEP
• WPA How does it work?
• WPA Practice
• Location, location, location
• Cracking the key
• Bruteforce
• WPA - Tools
• Airbase-ng
• Tkiptun-ng
• Airolib-ng
• Practical stuff

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WPA Location

• Need all packets from the 4 way handshake gt hear
  AP and Client
• In fact, aircrack-ng can work with less than 4
  packets
• If too far, wont get everything

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WPA Location (2)
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WPA Location (3)
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WPA Cracking the key

• Processing Unit
• CPU
• GPU (CUDA and AMD Stream)
• Method
• Wordlist
• Bruteforce
•  Rainbow  tables

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WPA - CUDA

• Cracking with your nVidia
• Much faster than with a CPU (10-100x)
• Intel P4 3.2Ghz 150 keys/sec
• AMD Turion 64 X2 TL-60 (2Ghz) 230 keys/sec
• Nvidia 280GTX 11000 keys/sec
• A few tools exists
• Commercial
• Open source pyrit
• Planned in aircrack-ng (AMD Stream too)

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WPA - Pyrit cracking speed
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WPA - Bruteforce

• Lets calculate how much time it will take to
  crack a simple passphrase with alphanumerical
  values (upper and lower case).
• Smallest WPA passphrase 8 characters (max 63).

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WPA - Bruteforce (2)

• 8 characters passphrase
• 62 possibilities per character A-Za-z0-9
• Using a 280GTX (11000keys/sec)
• 628 218 340 105 584 896 possible keys
• 218340105584896/11000k/s 19 849 100 508 sec
• 19849100508 sec 5 513 639 hours
• 5513639 hours 229 735 days
• 229735 days 630 years

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630 years for a 8 char WPA key

• A bit too long for a simple passphrase.
• For a 12 characters passphrase, bruteforce will
  take 9 309 091 680 years.
• Dictionnary attack and John The ripper are still
  the best solution.

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• WEP
• WPA How does it work?
• WPA Practice
• Location, location, location
• Cracking the key
• Bruteforce
• WPA - Tools
• Airbase-ng
• Tkiptun-ng
• Airolib-ng
• Practical stuff

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Airbase-ng

• Airbase-ng is multi-purpose tool aimed at
  attacking clients as opposed to the Access Point
  (AP) itself.
• Features
• Soft AP/Ad hoc
• Karma
• Encrypt/Decrypt packets
• Capture WPA handshake from a client.
• Filtering to avoid disturbing nearby networks

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Airbase-ng (2)

• Turn any monitor-mode capable card into an AP
• Default mode Karma
• Karmetasploit airbase-ng metasploit

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Fun with airbase-ng

• Karma
• airbase-ng rausb0
• Soft AP
• airbase-ng y e myAP c 6 rausb0
• ifconfig at0 up 192.168.0.254
• ping/ssh/ it from the client
• Script to manipulate packets
• airbase-ng Y both rausb0
• ./test/replay.py at1

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Fun with airbase-ng (2)

• WPA Handshake capture
• airbase-ng -z 2 -W 1 y -c 6 -e home rausb0
• Location problem solved ), you just need the
  client

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Tkiptun-ng

• Exaggerated in the news, only a few frames can be
  sent
• Work in Progress
• Basic documentation written
• Not fully working yet

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Tkiptun-ng (2)

• WPA TKIP QoS (802.11e)
• Decrypt packets from the AP
• Modified chopchop
• Breaks the MIC key
• Save plaintext keystream

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Airolib-ng

• Create pre-computed WPA hash tables to be used
  with aircrack-ng
• Uses a sqlite database
• Import/Export
• Import passphrases/essid lists
• Cowpatty tables (genpmk)
• Pyrit can exports its hash tables to airolib-ng
  format
• Speed (once precomputed)
• EEE 701 (900Mhz, SD Card) 9700keys/sec
• AMD Turion 64 X2 TL-60 (2Ghz, HDD 7200rpm)
  55500 keys/sec (30000 keys/sec virtualized).

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Conclusion

• Questions?
• Practical stuff
• WPA Cracking
• Fun Aigraph-ng