how_to_crack_wep_with_no_clients
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how_to_crack_wep_with_no_clients [2007/08/21 01:26] – added -i (case insensitive) to grep example darkaudax | how_to_crack_wep_with_no_clients [2009/09/26 14:34] – Fixed typos darkaudax | ||
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====== Tutorial: How to crack WEP with no wireless clients ====== | ====== Tutorial: How to crack WEP with no wireless clients ====== | ||
- | Version: 1.11 August 20, 2007 \\ | + | Version: 1.15 September 26, 2009 \\ |
By: darkAudax \\ | By: darkAudax \\ | ||
Video: [[http:// | Video: [[http:// | ||
- | |||
===== Introduction ===== | ===== Introduction ===== | ||
- | There are many times when a wireless network has no wireless clients associated with it and there are no ARP requests coming from the wired side. This tutorial describes how to crack the WEP key when there are no wireless clients and there are no ARP requests coming from the wired side. Although this topic has been discussed many times over in the [[http:// | + | There are many times when a wireless network has no wireless clients associated with it and there are no ARP requests coming from the wired side. This tutorial describes how to crack the WEP key when there are no wireless clients and there are no ARP requests coming from the wired side. Although this topic has been discussed many times over in the [[http:// |
- | If there ARP requests being broadcast from the wire side, then the standard [[fake_authentication|fake authentication]] combined with [[arp-request_reinjection|ARP request replay technique]] may be used. | + | If there ARP requests being broadcast from the wire side, then the standard [[fake authentication]] combined with [[arp-request_reinjection|ARP request replay technique]] may be used. |
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:// | + | I would like to acknowledge and thank the [[http:// |
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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*There are some data packets coming from the access point. | *There are some data packets coming from the access point. | ||
* The access point uses WEP "open authentication" | * The access point uses WEP "open authentication" | ||
+ | * You use the native MAC address of your wireless card for all the steps and do not change it. Do NOT use any other MAC address as the source for transmitting packets. | ||
* You are using v0.9 of aircrack-ng. If you use a different version then some of the command options may have to be changed. | * You are using v0.9 of aircrack-ng. If you use a different version then some of the command options may have to be changed. | ||
Ensure all of the above assumptions are true, otherwise the advice that follows will not work. In the examples below, you will need to change " | Ensure all of the above assumptions are true, otherwise the advice that follows will not work. In the examples below, you will need to change " | ||
- | |||
- | In the examples, the option " | ||
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*2 - Start the wireless interface in monitor mode on the specific AP channel | *2 - Start the wireless interface in monitor mode on the specific AP channel | ||
*3 - Use aireplay-ng to do a fake authentication with the access point | *3 - Use aireplay-ng to do a fake authentication with the access point | ||
- | *4 - Use aireplay-ng chopchop or fragmenation | + | *4 - Use aireplay-ng chopchop or fragmentation |
*5 - Use packetforge-ng to create an arp packet using the PRGA obtain in the previous step | *5 - Use packetforge-ng to create an arp packet using the PRGA obtain in the previous step | ||
*6 - Start airodump-ng on AP channel with filter for bssid to collect the new unique IVs | *6 - Start airodump-ng on AP channel with filter for bssid to collect the new unique IVs | ||
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To be honest, we will not be changing the wireless card MAC address. | To be honest, we will not be changing the wireless card MAC address. | ||
- | This is a reminder to use your wireless card MAC address as the source MAC. I mention this explicitly as a reminder to use the actual MAC address from your card in "Step 3 - fake authentication" | + | This is a reminder to use your wireless card MAC address as the source MAC. I mention this explicitly as a reminder to use the actual MAC address from your card in "Step 3 - fake authentication" |
==== Step 2 - Start the wireless interface in monitor mode on AP channel ==== | ==== Step 2 - Start the wireless interface in monitor mode on AP channel ==== | ||
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| | ||
- | Note: In this command we use " | + | Note: In this command we use " |
The system will respond: | The system will respond: | ||
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Tx excessive retries: | Tx excessive retries: | ||
- | 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. 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. 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: | ||
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=== Troubleshooting Tips === | === Troubleshooting Tips === | ||
- | *If another interface started other then ath0 then stop all of them first by using " | + | *If another interface started other than ath0 then stop all of them first by using " |
+ | *On mac80211-based drivers, airmon-ng will respond with something like this: | ||
+ | | ||
+ | |||
+ | | ||
+ | | ||
+ | |||
+ | For such interfaces, use the interface name after " | ||
==== Step 3 - Use aireplay-ng to do a fake authentication with the access point ==== | ==== Step 3 - Use aireplay-ng to do a fake authentication with the access point ==== | ||
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*-e teddy is the wireless network name | *-e teddy is the wireless network name | ||
*-a 00: | *-a 00: | ||
- | *-h 00: | + | *-h 00: |
*ath0 is the wireless interface name | *ath0 is the wireless interface name | ||
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If you want to select only the DeAuth packets with tcpdump then you can use: " | If you want to select only the DeAuth packets with tcpdump then you can use: " | ||
- | |||
- | |||
- | |||
==== Step 4 - Use aireplay-ng chopchop or fragmenation attack to obtain PRGA ==== | ==== Step 4 - Use aireplay-ng chopchop or fragmenation attack to obtain PRGA ==== | ||
- | The objective of the [[korek_chopchop|chopchop]] and [[fragmentation]] attacks is to obtain a PRGA (pseudo random | + | The objective of the [[korek_chopchop|chopchop]] and [[fragmentation]] attacks is to obtain a PRGA (pseudo random |
- | Either chopchop or fragmentation attacks can be to obtain the PRGA bit file. The result is the same so use whichever one works for you. The pros and cons of each attack are described on the [[aircrack-ng]] page. | + | Either chopchop or fragmentation attacks can be to obtain the PRGA bit file. The result is the same so use whichever one works for you. The pros and cons of each attack are described on the [[aircrack-ng]] page. |
- | We will cover the fragmentation | + | We will cover the fragmentation |
| | ||
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=== Helpful Tips === | === Helpful Tips === | ||
- | *Be sure the packet is 68 or more bytes otherwise you may not have enough PRGA data to subsquently | + | *Be sure the packet is 68 or more bytes otherwise you may not have enough PRGA data to subsequently |
- | *At home, to generate some packets to force chopchop to start, ping a non-existant | + | *At home, to generate some packets to force chopchop to start, ping a nonexistent |
*You can check the decrypted packet by running " | *You can check the decrypted packet by running " | ||
| | ||
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* The chopchop attack will not be successful on some access points. If this happens, move onto the fragmentation attack. | * The chopchop attack will not be successful on some access points. If this happens, move onto the fragmentation attack. | ||
* Make sure you are properly associated. To check this, follow the tcpdump instructions in step 2. | * Make sure you are properly associated. To check this, follow the tcpdump instructions in step 2. | ||
+ | |||
==== Step 5 - Use packetforge-ng to create an arp packet ==== | ==== Step 5 - Use packetforge-ng to create an arp packet ==== | ||
- | In the previous step, we obtained PRGA. It does not matter which attack generated the PRGA, both are equal. | + | In the previous step, we obtained PRGA. It does not matter which attack generated the PRGA, both are equal. |
But first, lets generate the arp packet for injection by entering: | But first, lets generate the arp packet for injection by entering: | ||
- | | + | |
Where: | Where: | ||
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*-h 00: | *-h 00: | ||
*-k 255.255.255.255 is the destination IP (most APs respond to 255.255.255.255) | *-k 255.255.255.255 is the destination IP (most APs respond to 255.255.255.255) | ||
- | *-l 255.255.255.255.255 is the source IP (most APs respond to 255.255.255.255) | + | *-l 255.255.255.255 is the source IP (most APs respond to 255.255.255.255) |
*-y fragment-0203-180343.xor is file to read the PRGA from | *-y fragment-0203-180343.xor is file to read the PRGA from | ||
*-w arp-request is name of file to write the arp packet to | *-w arp-request is name of file to write the arp packet to | ||
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Where: | Where: | ||
*-c 9 is the channel for the wireless network | *-c 9 is the channel for the wireless network | ||
- | *- -bssid 00: | + | *-'''' |
- | *- -ivs specfifies that you only want to capture the IVs. This keeps the file as small as possible. | + | *-w capture is file name prefix for the file which will contain the captured packets. |
- | *-w capture is file name prefix for the file which will contain the IVs. | + | |
*ath0 is the interface name. | *ath0 is the interface name. | ||
- | + | ==== Step 7 - Inject the arp packet ==== | |
- | ==== Step 7 - | + | |
Using the console session where you generated the arp packet, enter: | Using the console session where you generated the arp packet, enter: | ||
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Start another console session and enter: | Start another console session and enter: | ||
- | | + | |
Where: | Where: | ||
- | *-z means to use the PTW WEP-cracking method. | ||
*capture*.cap selects all dump files starting with " | *capture*.cap selects all dump files starting with " | ||
*-b 00: | *-b 00: | ||
- | You can run this while generating packets. | + | You can run this while generating packets. |
- | + | ||
- | If you don't use the " | + | |
Troubleshooting Tips: | Troubleshooting Tips: | ||
*Sometimes you need to try various techniques to crack the WEP key. Try " | *Sometimes you need to try various techniques to crack the WEP key. Try " | ||
+ | |||
===== Alternate Solution ===== | ===== Alternate Solution ===== | ||
There is a neat trick which simplifies cracking WEP with no clients. | There is a neat trick which simplifies cracking WEP with no clients. | ||
- | |||
- | It is important to understand that if you use this trick, then you can't use the " | ||
OK, at this point you are asking why didn't you show me this technique right at the start? | OK, at this point you are asking why didn't you show me this technique right at the start? | ||
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*-2 means use interactive frame selection | *-2 means use interactive frame selection | ||
*-p 0841 sets the Frame Control Field such that the packet looks like it is being sent from a wireless client. | *-p 0841 sets the Frame Control Field such that the packet looks like it is being sent from a wireless client. | ||
- | *c FF: | + | *-c FF: |
*-b 00: | *-b 00: | ||
*-h 00: | *-h 00: | ||
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Where " -r capture-01.cap" | Where " -r capture-01.cap" | ||
+ | |||
+ | ===== Using Another Source MAC Address ===== | ||
+ | |||
+ | The base tutorial assumes you are using the native MAC address of your wireless device as the source MAC. If this is not the case, then you need to change the process used. Since this is an advanced topic, I will provide the general guidelines and not the specific detail. | ||
+ | |||
+ | Preferably, you should change the native MAC address of your wireless device to the MAC you will be spoofing. |
how_to_crack_wep_with_no_clients.txt · Last modified: 2018/03/11 20:15 by mister_x