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Date: Sat, 17 Dec 2011 16:58:45 +0400
From: Solar Designer <solar@...nwall.com>
To: john-dev@...ts.openwall.com
Subject: Re: Bit slice implementation of DES based hashes

Piyush -

On Sat, Dec 17, 2011 at 02:33:51PM +0530, piyush mittal wrote:
> Also one more difficulty I am facing is that in Oracle hashes key is fixed
> i.e 0x123456789ABCDEF and therefore in JTR we need to brute force by taking
> different plain text to get the same cipher text.However in other
> implementations of  Bit slice DES like LM, BSDI,Traditional DES, the key is
> not fixed but plain text is fixed

Yes, but this should be no problem for you.

> so accordingly all the functions are
> defined and therefore I can't reuse the same code.

Why not?  From what you wrote above, it sounds like you simply need an
extra function to set the initial DES block, but then you can use a
trivial variation of the existing DES_bs_crypt_LM() as I had suggested.

> Now I need to make
> separate functions for oracle.Some of the functions that I need to change
> are as follows
> 
> DES_bs_set_key()

Why?  If you only have one fixed key to use (note: I did not check
whether this is the case or not), then you can simply call the existing
DES_bs_set_key() with that key for all bit layers (0 to DES_BS_DEPTH-1)
in init().

> DES_bs_clear_keys()

Please update to 1.7.9-jumbo-5.  There's no DES_bs_clear_keys() in
1.7.9+, and there have been other changes to the bitslice DES code as
well.  Your patch should be against 1.7.9+'ish code.

> DES_bs_crypt()

As I suggested, DES_bs_crypt_LM() is a closer match.  DES_bs_crypt()
adds salts and iterations, which you don't need.

> However I am working on it but it will take little extra time.

OK.  Thank you for the status update!

Alexander

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