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cracking_wpa [2009/09/25 21:22]
darkaudax
cracking_wpa [2018/03/11 20:10] (current)
mister_x Removed link to trac
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 ====== Tutorial: How to Crack WPA/WPA2 ====== ====== Tutorial: How to Crack WPA/WPA2 ======
-Version: 1.18 September 252009\\+Version: 1.20 March 072010\\
 By: darkAudax By: darkAudax
  
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 It is recommended that you experiment with your home wireless access point to get familiar with these ideas and techniques. If you do not own a particular access point, please remember to get permission from the owner prior to playing with it. It is recommended that you experiment with your home wireless access point to get familiar with these ideas and techniques. If you do not own a particular access point, please remember to get permission from the owner prior to playing with it.
- 
-I would like to acknowledge and thank the [[http://​trac.aircrack-ng.org/​wiki/​Team|Aircrack-ng team]] for producing such a great robust tool.  
  
 Please send me any constructive feedback, positive or negative. Additional troubleshooting ideas and tips are especially welcome. Please send me any constructive feedback, positive or negative. Additional troubleshooting ideas and tips are especially welcome.
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 ===== Equipment used ===== ===== Equipment used =====
- 
-To follow this tutorial at home, you must have two wireless cards. 
  
 In this tutorial, here is what was used: In this tutorial, here is what was used:
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 ==== Step 1 - Start the wireless interface in monitor mode ==== ==== Step 1 - Start the wireless interface in monitor mode ====
  
-The purpose of this step is to put your card into what is called monitor mode.  Monitor mode is the mode whereby your card can listen to every packet in the air.  Normally your card will only "​hear"​ packets addressed to you.  By hearing every packet, we can later capture the WPA/WPA2 4-way handshake. ​ As well, it will allow us to optionally deauthenticate a wireless client in a later step. These steps are mostly specific ​to the madwifi-ng ​driver ​- for other driversthis procedure varies(Most commonlyrunning ​the command ​"airmon-ng start <​interface>​" ​is used to set up monitor mode.)+The purpose of this step is to put your card into what is called monitor mode.  Monitor mode is the mode whereby your card can listen to every packet in the air.  Normally your card will only "​hear"​ packets addressed to you.  By hearing every packet, we can later capture the WPA/WPA2 4-way handshake. ​ As well, it will allow us to optionally deauthenticate a wireless client in a later step. 
 + 
 +The exact procedure for enabling monitor mode varies depending on the driver you are using. To determine the driver (and the correct procedure ​to follow), run the following command: 
 + 
 +   ​airmon-ng 
 + 
 +On a machine with a Ralink, an Atheros and a Broadcom wireless card installed, the system responds: 
 + 
 +   ​Interface ​      ​Chipset ​        ​Driver 
 +    
 +   ​rausb0 ​         Ralink RT73     ​rt73 
 +   ​wlan0 ​          ​Broadcom ​       b43 - [phy0] 
 +   ​wifi0 ​          ​Atheros ​        madwifi-ng 
 +   ​ath0 ​           Atheros ​        ​madwifi-ng VAP (parent: wifi0) 
 + 
 +The presence of a [phy0] tag at the end of the driver name is an indicator ​for mac80211so the Broadcom card is using a mac80211 driver**Note that mac80211 is supported only since aircrack-ng v1.0-rc1and it won't work with v0.9.1.** 
 +Both entries of the Atheros card show "madwifi-ng" ​as the driver - follow the madwifi-ng-specific steps to set up the Atheros card. 
 +Finally, the Ralink shows neither of these indicators, so it is using an ieee80211 driver - see the generic instructions for setting it up. 
 + 
 +=== Step 1a - Setting up madwifi-ng ===
  
  
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 In the response above, you can see that ath0 is in monitor mode, on the 2.452GHz frequency which is channel 9 and the Access Point shows the MAC address of your wireless card.  Only the madwifi-ng drivers show the card MAC address in the AP field, other drivers do not.  So everything is good.   It is important to confirm all this information prior to proceeding, otherwise the following steps will not work properly. In the response above, you can see that ath0 is in monitor mode, on the 2.452GHz frequency which is channel 9 and the Access Point shows the MAC address of your wireless card.  Only the madwifi-ng drivers show the card MAC address in the AP field, other drivers do not.  So everything is good.   It is important to confirm all this information prior to proceeding, otherwise the following steps will not work properly.
  
-To match the frequency to the channel, check out: +To match the frequency to the channel, check out: http://www.cisco.com/en/US/​docs/​wireless/​technology/​channel/​deployment/​guide/Channel.html#​wp134132 ​.  This will give you the frequency for each channel. 
-http://www.rflinx.com/help/calculations/#​2.4ghz_wifi_channels then select the "​Wifi ​Channel ​Selection and Channel Overlap"​ tab.  This will give you the frequency for each channel.+ 
 +=== Step 1b - Setting up mac80211 drivers === 
 + 
 +Unlike madwifi-ng, you do not need to remove the wlan0 interface when setting up mac80211 drivers. Instead, use the following command to set up your card in monitor mode on channel 9: 
 + 
 +   ​airmon-ng start wlan0 9 
 + 
 +The system responds: 
 + 
 +   ​Interface ​      ​Chipset ​        ​Driver 
 +    
 +   ​wlan0 ​          ​Broadcom ​       b43 - [phy0] 
 +                                   ​(monitor mode enabled on mon0) 
 + 
 +Notice that airmon-ng enabled monitor-mode //on mon0//. So, the correct interface name to use in later parts of the tutorial is mon0. Wlan0 is still in regular (managed) mode, and can be used as usual, provided that the AP that wlan0 is connected to is on the same channel as the AP you are attacking, and you are not performing any channel-hopping. 
 + 
 +To confirm successful setup, run "​iwconfig"​. The following output should appear: 
 + 
 +   ​lo ​       no wireless extensions. 
 + 
 +   ​eth0 ​     no wireless extensions. 
 +    
 +   ​wmaster0 ​ no wireless extensions. 
 +    
 +   ​wlan0 ​    IEEE 802.11bg ​ ESSID:""​ 
 +             ​Mode:​Managed ​ Frequency:​2.452 GHz  Access Point: Not-Associated 
 +             ​Tx-Power=0 dBm 
 +             Retry min limit:​7 ​  RTS thr:​off ​  ​Fragment thr=2352 B 
 +             ​Encryption key:off 
 +             Power Management:​off 
 +             Link Quality:​0 ​ Signal level:​0 ​ Noise level:0 
 +             Rx invalid nwid:​0 ​ Rx invalid crypt:​0 ​ Rx invalid frag:0 
 +             Tx excessive retries:​0 ​ Invalid misc:​0 ​  ​Missed beacon:0 
 +    
 +   ​mon0 ​     IEEE 802.11bg ​ Mode:​Monitor ​ Frequency:​2.452 GHz  Tx-Power=0 dBm 
 +             Retry min limit:​7 ​  RTS thr:​off ​  ​Fragment thr=2352 B 
 +             ​Encryption key:off 
 +             Power Management:​off 
 +             Link Quality:​0 ​ Signal level:​0 ​ Noise level:0 
 +             Rx invalid nwid:​0 ​ Rx invalid crypt:​0 ​ Rx invalid frag:0 
 +             Tx excessive retries:​0 ​ Invalid misc:​0 ​  ​Missed beacon:0 
 + 
 + 
 +Here, mon0 is seen as being in monitor mode, on channel 9 (2.452GHz). Unlike madwifi-ng, the monitor interface has no Access Point field at all. Also notice that wlan0 is still present, and in managed mode - this is normal. Because both interfaces share a common radio, they must always be tuned to the same channel - changing the channel on one interface also changes channel on the other one. 
 + 
 +=== Step 1c - Setting up other drivers === 
 + 
 +For other (ieee80211-based) drivers, simply run the following command to enable monitor mode (replace rausb0 with your interface name): 
 + 
 +   ​airmon-ng start rausb0 9 
 + 
 +The system responds: 
 + 
 +   ​Interface ​      ​Chipset ​        ​Driver 
 +    
 +   ​rausb0 ​         Ralink ​         rt73 (monitor mode enabled)
  
 +At this point, the interface should be ready to use.
  
 ==== Step 2 - Start airodump-ng to collect authentication handshake ==== ==== Step 2 - Start airodump-ng to collect authentication handshake ====
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 To see if you captured any handshake packets, there are two ways.  Watch the airodump-ng screen for " WPA handshake: 00:​14:​6C:​7E:​40:​80"​ in the top right-hand corner. ​ This means a four-way handshake was successfully captured. ​ See just above for an example screenshot. To see if you captured any handshake packets, there are two ways.  Watch the airodump-ng screen for " WPA handshake: 00:​14:​6C:​7E:​40:​80"​ in the top right-hand corner. ​ This means a four-way handshake was successfully captured. ​ See just above for an example screenshot.
  
-use Wireshark and apply a filter of "​eapol"​. ​ This displays only eapol packets you are interested in.  Thus you can see if capture contains 0,1,2,3 or 4 eapol packets.+Use Wireshark and apply a filter of "​eapol"​. ​ This displays only eapol packets you are interested in.  Thus you can see if capture contains 0,1,2,3 or 4 eapol packets.
  
  
 ==== Step 3 - Use aireplay-ng to deauthenticate the wireless client ==== ==== Step 3 - Use aireplay-ng to deauthenticate the wireless client ====
  
-This step is optional. ​ You only perform this step if you opted to actively speed up the process. ​ The other constraint is that there must be a wireless client currently associated with the AP.  If there is no wireless client currently associated with the AP, then move onto the next step and be patient. ​ Needless to say, if a wireless client shows up later, you can backtrack and perform this step.+This step is optional.  If you are patient, you can wait until airodump-ng captures a handshake when one or more clients connect to the AP.  You only perform this step if you opted to actively speed up the process. ​ The other constraint is that there must be a wireless client currently associated with the AP.  If there is no wireless client currently associated with the AP, then you have to be patient ​and wait for one to connect to the AP so that a handshake can be captured.  Needless to say, if a wireless client shows up later and airodump-ng did not capture the handshake, you can backtrack and perform this step.
  
 This step sends a message to the wireless client saying that that it is no longer associated with the AP.  The wireless client will then hopefully reauthenticate with the AP.  The reauthentication is what generates the 4-way authentication handshake we are interested in collecting. ​ This is what we use to break the WPA/WPA2 pre-shared key. This step sends a message to the wireless client saying that that it is no longer associated with the AP.  The wireless client will then hopefully reauthenticate with the AP.  The reauthentication is what generates the 4-way authentication handshake we are interested in collecting. ​ This is what we use to break the WPA/WPA2 pre-shared key.
cracking_wpa.1253906543.txt.gz · Last modified: 2009/09/25 21:22 by darkaudax