P-ppk-crack will try to brute force PuTTY generated private key passphrases.
The source code is based on putty svn version (actually on plink), check http://chiark.greenend.org.uk/~sgtatham/putty/licence.html. This is just a quick-hack, which demonstrates that you should use a strong passphrase for your private key!
Example using John the ripper v1.7.2
1 2 3 4 5 6 | Microsoft Windows [Version 6.0.6000] Copyright (c) 2006 Microsoft Corporation. Alle Rechte vorbehalten. C:\>jo-hn -stdout -incremental | p-ppk-crack password.ppk p-ppk-crack v0.5 made by michu@neophob.com - PuTTY private key cracker len: 148/352 trying 65808 keys/s, # of tested keys: 1711001. |
This test ran inside a VMWare machine, the host system is W2K Pro. On the host system the performance was arround 35’000 k/s, looks like Vista is quite faster…

4 Comments
1 Abdussamad wrote:
Interesting. Could you explain something to me? Why does puttygen ask for a passphrase instead of a password? I mean a passphrase would imply something that uses dictionary words while a password could include numeric characters as well as punctuation marks. A password is more difficult to crack then. So why doesn’t the software just ask us to use a password?
2 me wrote:
how the *hell* do you use it??
3 michu wrote:
hint: rtfm!
4 Vandog wrote:
U need also John the Ripper for this Programm