john-users - Re: Cracking a GPG keyring

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Date: Tue, 4 Dec 2012 16:59:21 +0530
From: Dhiru Kholia <dhiru.kholia@...il.com>
To: john-users@...ts.openwall.com
Subject: Re: Cracking a GPG keyring

On Tue, Dec 4, 2012 at 10:52 AM, Haneef Mubarak <haneef503@...il.com> wrote:
> I forgot the passphrase to my GPG keyring. I was wondering if there was a way to
> crack the passphrase using JTR. I have a the highest workstation model Xeon on
> Sandy Bridge on the market, along w/ a GTX 690. I have the CUDA toolkit and have
> managed to compile and test JTR.
>
> I went and searched all over the place (Google), and couldn't find much. I was
> wondering if someone could please point me to a specific command (ie: ./john
> ...) or a series of commands.

http://www.ubuntuvibes.com/2012/10/recover-your-gpg-passphrase-using-john.html

https://github.com/magnumripper/JohnTheRipper/blob/unstable-jumbo/doc/README.gpg

$ ../run/john -fo:gpg-opencl <hashfile>

Ensure that your key uses SHA1 based s2k function before using the
OpenCL gpg format.

Let us know if  you run into specific problems.

-- 
Cheers,
Dhiru