Cracking AES

David Shaw
Fri May 16 03:55:48 2003

Hash: SHA1

On Mon, May 12, 2003 at 12:04:00AM -0500, Adam Smith wrote:
> I run a mixed Win32/OpenBSD environment but am far more familiar with
> Windows.  I set up a batch file like so:
> @echo off
> echo GUESS1|gpg.exe -q --passphrase-fd 0 --output text.out --decrypt
> text.pgp
> echo GUESS2|gpg.exe -q --passphrase-fd 0 --output text.out --decrypt
> text.pgp
> ...
> This does not work for me, however, because GPG messes up when you try
> to feed it a '&' through this method (I'm escaping all of the special
> characters in echo using a '^' but can't find an escape character for
> GPG).  Any suggestions

I'm curious why you're having a problem with '&'.  The only character
that should be a unusable via passphrase-fd is a newline.

> Even if it did work, however, I'd still like to be able to do more than
> 8 tries per second.  With the right kind of coding I should be able to
> easily get 10,000 tries/second but do not have any experience.  Is
> source code available for the Windows binary (I could not find it)?
> Anyone ever done this before?

The source code for all versions of GnuPG is available at  The Windows code is the same as the Unix code
(more or less).  Read the code in g10/seckey-cert.c and
g10/passphrase.c, in particular, for the code that handles secret key
decryption.  You should be able to hotwire it to do what you want.

Version: GnuPG v1.2.3-cvs (GNU/Linux)