john-users - new user help with list vs. incremental modes

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Date: Mon, 17 Dec 2012 12:54:00 -0600
From: Raleigh Rinehart <rrinehart@...-estech.com>
To: john-users@...ts.openwall.com
Subject: new user help with list vs. incremental modes

Hi All,

I am new to JtR and am trying to test things out.  To that end, I've
downloaded and installed JtR to my Mac box (happens to be the most powerful
machine currently available).
Here is the version I am running:  John the Ripper password cracker, ver:
1.7.9-jumbo-7 [macosx-x86-64-gpu]

My question is this:  how do I best configure JtR to run for a known
password pattern?  For example, if I know ahead of time the password is
going to be of the form 3-6 alpha-numerical characters followed by 3-8
digits?  I've gone through the documents, mailing lists and other resources
but am still confused on the best approach attack to this.

Here is what I've done so far.

I tried creating a "digits_list.txt" file by running:
  john --incremental=digits --stdout=8 > digits_list.txt

Then I created a new List rule like this:
    [List.Rules:Foo]
    A0"[0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z]"
    A0"[0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z]"
    A0"[0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z]"

A0"[0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z][0-9a-zA-Z]"

When I run that with:
    ./john --format=raw-sha512-cuda --device=1 --session:foo
--wordlist=digits_list.txt -rules:Foo crackme.txt
 JtR just seems to do nothing.  I let it run for a couple of hours but it
never seemed to do anything.
Running the status command returns this:
    ./john --status=foo
    fopen: foo.rec: No such file or directory

And I don't see any log files get created either (i.e. foo.log)

I am guessing it is because the digits_list.txt is too big (~950meg) or the
way I've tried setting up the mangling is too inefficient.

So my next idea is to try and use 'incremental' mode.  However I am at a
loss as to how to configure that to run for a password pattern like the
above.

Any ideas, pointers or insights would be greatly appreciated!

thanks,
-raleigh

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