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Date: Thu, 7 May 2015 17:16:11 +0300
From: Solar Designer <>
Subject: Re: get_binary_*() and get_hash_*() methods

On Thu, May 07, 2015 at 02:02:36PM +0300, Aleksey Cherepanov wrote:
> get_hash[]() should be called for each computed hash, cmp_all()
> without get_hash[]() should be called for each loaded hash.
> It would be possible to remove get_hash[]() calls if crypt_all
> returned the values in array: john provides a pointer to array of ints
> (BTW why not unsigned int?) of length MAX_KEYS_PER_CRYPT to
> crypt_all(), and crypt_all fills the array with values like from
> get_hash[6](). Though the length of array should be a separate field
> in the format structure because crypt_all() may produce more
> candidates.

The caller will not always need those partial hashes.  For some formats,
e.g. for bitslice DES, they are costly to produce.  When cracking only a
handful of hashes, it is quicker to call cmp_all() right away, without
going through get_hash[]() first.


	threshold = password_hash_thresholds[0];
	if (db->format && (db->format->params.flags & FMT_BS)) {
 * Estimate the complexity of DES_bs_get_hash() for each computed hash (but
 * comparing it against less than 1 loaded hash on average due to the use of a
 * hash table) vs. the complexity of DES_bs_cmp_all() for all computed hashes
 * at once (but calling it for each loaded hash individually).
		threshold = 5 * ARCH_BITS / ARCH_BITS_LOG + 1;


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