Date: Wed, 23 Nov 2005 03:30:39 +0300 From: Solar Designer <solar@...nwall.com> To: john-users@...ts.openwall.com Subject: Re: Speed up John On Wed, Nov 23, 2005 at 02:55:49AM +0300, Solar Designer wrote: > On Tue, Nov 22, 2005 at 11:36:58PM +0100, Frank Dittrich wrote: > > The master could just once precompute all password candidates, > > Unfortunately, it would take one of the fastest CPUs available today > almost 30 years to do that with the code currently in John. A clarification: this estimate _includes_ the overhead of stdio and the kernel (with output into /dev/null) since Frank's proposal was to abuse the --stdout option without code modifications. Simply commenting out the puts() line triples the performance, bringing the rate up to 20M candidates/second (on the fastest CPUs currently available) and the time to generate them all down to 10 years. Commenting out even more stuff in crk_process_key(), except for the events check and the status_update_crypts() call, makes the performance almost 10x better than the original, for a rate of up to 70M candidates per second (but the .rec file is not getting updated, then). -- Alexander Peslyak <solar at openwall.com> GPG key ID: B35D3598 fp: 6429 0D7E F130 C13E C929 6447 73C3 A290 B35D 3598 http://www.openwall.com - bringing security into open computing environments Was I helpful? Please give your feedback here: http://rate.affero.net/solar
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