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Python Perl


A tool for parsing and decrypting MS-CHAPv2 network handshakes.

  1. The first thing you'll need to do is obtain the network traffic for the MS-CHAPv2 handshake you'd like to crack.

    For PPTP VPN connections, simply use a tool such as tcpdump or wireshark in order to obtain a network capture. For WPA2 Enterprise wireless handshakes, simply use a tool like FreeRADIUS-WPE in order to obtain 'challenge' and 'response' parameters.

  2. Next you'll use chapcrack in order to parse and extract the MS-CHAPv2 handshake from your packet capture or FreeRADIUS interception.

    1. For a PPTP handshake, run: parse -i /path/to/capture.cap
    2. For a WPA2 handshake, run radius -C <challenge> -R <response>, where challenge and response are what you intercepted with FreeRADIUS-WPE
  3. Submit the CloudCracker token chapcrack gives you to

  4. When you get your results, you can decrypt a PPTP packet capture: decrypt -i </path/to/capture.cap> -o output.cap -n <result>

Bug tracker

Have a bug? Please create an issue here on GitHub!


Copyright 2012 Moxie Marlinspike

Licensed under the GPLv3:

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