A tool for parsing and decrypting MS-CHAPv2 network handshakes. Upgraded version with Python 3, John The Ripper support.

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: chapcrack.py parse -i /path/to/capture.pcap
   2. For a WPA2 handshake, run chapcrack.py radius -C <challenge> -R <response>, where challenge and response are what you intercepted with FreeRADIUS-WPE

3. Crack the John the Ripper hash you received to get the plaintext password.

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

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

https://github.com/redsh4de/chapcrack/issues

Copyright 2012 Moxie Marlinspike

Licensed under the GPLv3: http://www.gnu.org/licenses/gpl-3.0.html