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Date: Wed, 25 Jul 2012 17:37:06 +0530
From: Dhiru Kholia <dhiru.kholia@...il.com>
To: john-dev@...ts.openwall.com
Subject: Re: Add support for cracking M$ Outlook's PST files

On Tue, Jul 24, 2012 at 11:31 PM, jfoug <jfoug@....net> wrote:
> Here is a faster version. It uses the pkzip.h crc table, But still 'can' use
> the pst-crc.h file also (just slower).
>
> I changed the OMP scale, and scale of non OMP builds (Dhiru, for fast
> hashes, you really need to change these, and stop using existing code you
> did for slow formats).

I still have to play around and understand these parameters. Thanks!

> For this code, there is a #define within crypt_all.  If that is set to 1,
> your header file code is used. If set to 0 (where it is set now), the pkzip
> code is used.
>
> The only difference from 'normal' CRC32 (like in pkzip) and this PST crc, is
> in the initialization, and lack of complement on ending.  But the crc poly
> is the same, and this is trivial to setup to use the existing tables.   The
> code was 'falsely' thinking that doing these CRC's 4 bytes at a time was
> faster. It may be faster on longer strings, but on shorter stuff (like JTR
> password cracking), the initial and post for loops slow things down beyond
> the gains seen.

I see that you have replaced ComputeCRC with pkzip_crc32. Did you
modify pkzip_crc32 code or did it work as it is?

Should this format be separate or can it be done in another format?

-- 
Cheers,
Dhiru

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