Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Fri, 8 Feb 2013 16:48:34 +0000
From: Jeremiah Grossman <jeremiah@...tehatsec.com>
To: "john-users@...ts.openwall.com" <john-users@...ts.openwall.com>
Subject: Re: Password Cracking a DMG...


On Feb 4, 2013, at 10:52 AM, Jeremiah Grossman <jeremiah@...tehatsec.com> wrote:

> 
> On Feb 1, 2013, at 3:12 PM, magnum <john.magnum@...hmail.com> wrote:
> 
>> On 29 Jan, 2013, at 22:10 , magnum <john.magnum@...hmail.com> wrote:
>>> On 29 Jan, 2013, at 21:01 , Jeremiah Grossman <jeremiah@...tehatsec.com> wrote:
>>>> On Jan 29, 2013, at 11:18 AM, magnum <john.magnum@...hmail.com> wrote:
>>>> 
>>>>> On 29 Jan, 2013, at 19:09 , Jeremiah Grossman <jeremiah@...tehatsec.com> wrote:
>>>>>> from run/
>>>>>> 
>>>>>>> $ dmg2john aes_256.dmg 
>>>>>> Segmentation fault: 11
>>>>>> 
>>>>>> Same issue as yesterday. "aes_256.dmg" is a newly created 15GB DMG encrypted with AES-256 (OS X 10.8.2). No data contained within. 
>>>>> 
>>>>> That should be "./dmg2john". Maybe you just didn't copy it verbatim? Otherwise, maybe you actually did not run the newly built ./dmg2john but an old bad one from somewhere in your path.
>>>>> 
>>>>> magnum
>>>> 
>>>> Positive I got it right. I was just snipping the command line for brevity sake. The dmg2john I ran was in the run/ directory automatically built during compile of JtR.
>>> 
>>> I figured so, just checking. I will try to reproduce the problem and debug it.
>> 
>> 
>> For people not subsribed to john-dev: This is resolved in latest git. The dmg2john bug was fixed, and then we realized both dmg2john and the format blatantly ignored the iterations count - which is bumped a lot in later OSX versions (it was hard-coded to 1000 while newer Macs produce files with over 200,000 iterations, and seemingly depending on available CPU power at creation time). Finally, some known-plain stuff was tweaked.
>> 
>> So the good news is everything hopefully works now if you check out a Git Jumbo. The bad news is with this high iteration count, you get about 5-10 c/s per core on CPU. Using OpenCL and GPU we can get a little more but this is the toughest format I know of right now.
>> 
>> magnum
> 
> 
> Downloaded the new version. Ran dmg2john across several different sized AES-256 DMGs (100MB, 200MB, 15GB) [no data]. Successfully cracked the password on all of them. Hooray! 
> 
> Now, onto the the "real" one. ;)
> 
> 
> Regards,
> 
> Jeremiah-


My story has a happy ending...

Password Cracking AES-256 DMGs and Epic Self-Pwnage
http://blog.whitehatsec.com/cracking-aes-256-dmgs-and-epic-self-pwnage/

If the missing characters of my partial password had been 7 characters, not sure it would have been. Thanks everyone!

Regards,

Jeremiah-


Powered by blists - more mailing lists

Your e-mail address:

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.