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Date: Wed, 06 May 2015 00:01:51 +0200
From: magnum <john.magnum@...hmail.com>
To: john-users@...ts.openwall.com
Subject: Re: Question on showing number of guesses tried
On 2015-05-05 23:14, Yulong wrote:
> Thanks!! It worked.
>
> Regarding to the inaccuracy, is it totally off? I mean, if we know how many
> passwords per "batch" we try, then the actual number of guesses would be
> just "displayed result"/"# per batch"? Thought the question now becomes how
> to know # of passwords per batch.
Well you can query it like this:
$ ../run/john --list=format-all-details --format=wpapsk
Format label wpapsk
Disabled in configuration file no
Min. password length in bytes 8
Max. password length in bytes 63
Min. keys per crypt 8
Max. keys per crypt 64 <-- this figure
(...)
So for WPAPSK format, it's 64 on my system (you may get a different
figure - it depends on build options, number of cores, AVX/AVX2 and
other things).
In that case, if a password is found among candidate 1-64, it will be
shown as 64. If it's found among 65-128, it will be shown as 128 and so
on. There is obviously no way to divide that number to get a more exact
figure.
However there IS a way to force "one key per batch" which will make the
figure exact, namely "--mkpc=1". But this will harm performance badly
(there's obviously a good reason for doing batches) so is only for
testing purposes.
Why do you need an exact figure? There are some ways to decrease the
batch size without totally ruining performance: For one, you should
disable OpenMP (rebuild using "./configure --disable-openmp"). For fast
formats like raw-md5 it wont be much slower (if at all). Your batch size
will shrink to 12 or so (depending on various factors).
magnum
> On Tue, May 5, 2015 at 4:52 PM, magnum <john.magnum@...hmail.com> wrote:
>
>> On 2015-05-05 22:19, Yulong wrote:
>>
>>> I am using jtr-1.8.0-jumbo-1. I would like to output number of guesses
>>> tried for each cracked password.
>>> (...)
>>> However, when I use "--crack-status", it still does not display the number
>>> of guesses:
>>>
>>> guesses: 1 time: 0:00:00:00 24.30% (ETA: Tue May 5 16:13:17 2015) c/s:
>>> 104020K trying: drupelet - duckling
>>>
>>> My command is "./run/john --crack-status --format=raw-md5
>>> --wordlist=wordlist.file password.file". I was wondering if I am doing it
>>> wrong, or the patch has been modified after it has been created?
>>>
>>
>> Unlike CrackStatus (john.conf option) a.k.a --crack-status (command line
>> option) there's no command line option for StatusShowCandidates. So you
>> need to edit john.conf and change StatusShowCandidates to "Y".
>>
>> Also please note that IIRC the figure you'll get may not be very exact.
>> For example, if a format tries 32 passwords per "batch" and you crack a
>> hash with the very first candidate, it may be shown as 32 instead of 1.
>> This gets worse with OpenMP and even worse with GPU, where we may have
>> hundreds of thousands or even millions of passwords in one batch...
>>
>> magnum
>>
>>
>>
>
>
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