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Date: Sat, 27 May 2006 11:36:41 +0200
From: "Otheus (aka Timothy J. Shelling)" <otheus@...il.com>
To: john-users@...ts.openwall.com
Subject: Parallalizing John the Ripper

On 5/26/06, Solar Designer <solar@...nwall.com> wrote:
>
> On Fri, May 26, 2006 at 08:34:26PM +0200, Otheus (aka Timothy J. Shelling)
> wrote:
> > I'm trying to modify it for MPI.
>
> Please refer to this john-users posting:
>
>
> http://article.gmane.org/gmane.comp.security.openwall.john.user/759
>
> and, more importantly, to two other postings referred from this one.  In
> particular, there's a link to an existing John/MPI hack.


I looked at his hack. First, it needs some updating to run on my AMD 64s.
I'm not sure what kind of updating, but going from 1.6.36 to .1.7.x will
require work one way or the other.  So I decided to look at the diffs in
Ryan's MPI patch.

It's clear that he splits the keyspace, but I'm not exactly sure how. I
think it's in inc.c between lines 471 and 483.  He modifies "ptr" with an
arbitrary multiplier ("3") times the number of MPI tasks. Anyone care to
share insight?

That's basically what the patch does, though it also individuates all the
files -- the .rec file, the .pot file, etc.

It seems to me that modifying the .pot file is not necessary, and modifying
the .rec file is only used for recovery.


I am thinking about re-doing his patch so that only the root task does any
of the file IO. The other tasks talk back to the root task when they find a
match. Recovery would happen about the same way. Finally, an --extend
filter() function could be used to divide the keyspace differently than a
default method.


-- 
Otheus
otheus@...il.com
+43.650.790.2571

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