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Date: Thu, 17 Feb 2011 11:41:13 -0600
From: "jfoug" <jfoug@....net>
To: <john-users@...ts.openwall.com>
Subject: MD5 Generic improvements

I have been working offline with Solar recently, due to benchmark testing
being broken for the md5-gen format.  The issue was found, and simple fix
addressed it in the jumbo-12 update.

 

I had a pretty large set of semi completed code improvements to md5-gen.  I
have taken the time to finalize these, and to add quite a few additional
things.  There are performance improvements (including intrinsic support, IF
the intrinsic patch is applied), and some overall performance improvements,
and certain sub formats improved significantly.

 

All of these changes can be found in the patch section of the wiki, at
http://openwall.info/wiki/john/patches  I have made these patches against
jumbo-12.  It is likely that this patch will be pulled into jumbo-13.
However, it is being released now, so that people can use the improvements
if they so choose.

 

Here is a list of changes.

 

1.       Incorporation of SSE2 intrinsic code.  This is triggered by the
MD5_PARA #define.  For this code to 'work', the SSE intrinsic patch will
need to be installed, and for most performance gains, the ICC will need to
be used as the compiling environment.  NOTE, this intrinsic code is
'pre-patched' in.  It is not part OF the intrinsic patch, but it will not
compile in UNTIL the intrinsic patch code is put in.  The intrinsic patch is
also found on the wiki 'patches' page.

2.       Incorporation of MD5_go code (faster than OpenSSL). There is a
#define in the source, which will still allow the original OpenSSL code to
be used (but for me, it is slower).

3.       Improvements in speed for specific sub formats (re-did the
scripting steps on a couple of them).

4.       Improvements overall in speed of SSE (some of the intermediate
level overhead reduced)

5.       Several new formats  (PostOffice-md5, and a format with 2 salts).
Numerous new formats scripted into the john.conf file, including pixMD5 and
pixMD5-salted.

6.       Addition of 8 'constants' that can be used in building sub formats.
There is an example for the PostOffice-md5, in the john.conf file)

7.       Prior builds of md5-gen for SSE (MMX) would not be able to handle
certain formats. Now the SSE builds do handle these formats (but drop back
to MD5_go, x86 code).  Formats which at any point within their processing
build a string longer than 54 bytes, will not be usable within SSE code,
since the SSE build only does a single 64 byte MD5 crypt.  So a format like
md5(md5($s)md5($p)) would not be valid within SSE builds.  However, with the
new change they do 'work', just at x86 speeds.

8.       Documentation updated

9.       john.conf updated.

10.   Added ability to do 2-salt formats (not sure if any 2-salt formats are
in actual use at this time).  This 'would' allow a format to be built to do
a salted format which also uses the user_id as a 2nd salt.  The input file
would have to be 'hand built' to do this, but it does put this type of
format into the grasp of john.

11.   Now, if a benchmark test fails in gen-md5, the testing continues and
stays 'in' the md5-gen, testing any sub formats still needing tested.

12.   Now, after the 'built in' formats are tested, the script formats in
john.conf are also tested (thus, the need to get the formats updated to the
newer syntax).

 

Jim.


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