john-users - Re: zero-salted sha1 (mac os x 10.4 hash) cracking

Openwall GNU/*/Linux 3.0 - a small security-enhanced Linux distro for servers

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date: Sat, 7 Apr 2012 03:04:26 +0400
From: Solar Designer <solar@...nwall.com>
To: john-users@...ts.openwall.com
Subject: Re: zero-salted sha1 (mac os x 10.4 hash) cracking

Hi,

I was hoping someone else would respond. ;-)

On Thu, Apr 05, 2012 at 05:50:29AM +0000, asdf asdf wrote:
> Hello,I have a small question about John the Ripper. I have a hash of a password in Mac OS X 10.4 (so it's zero-salted sha1, meaning the first 8 characters are the salt and are all 0). How do I get John to crack this?

It should be correctly autodetected by any version of John that supports
those hashes - such as jumbo or JtR Pro.  You don't need to do anything
special for this to happen.

> I tried SHA1p with an added salt, but it didn't recognise it.

Indeed.  Mac OS X hashes use a binary salt of a fixed size.  The correct
JtR "format" for hashes used by 10.4 through 10.6 is called XSHA, but
you don't need to specify it explicitly (although you may).  The $SHA1p$
hash encoding prefix is recognized by the sha1-gen format, which is
similar, except that it uses variable-length ASCII salts.

> Without specifying a salt, it did recognise it as "password hash (Mac OS X 10.4 - 10.6 salted SHA-1 [32/64])",

That's right.

> but since I got the salt, it would be a lot quicker if I could specify it, right?

No, it extracted the salt from your 48-char string already.

> So my question is: Can I specify a salt for Mac OS X passwords? If so how, if not, what would be a workaround.

You've already specified the salt in that 48-char string.  You don't
need to do anything else about that.

I hope this helps.

Alexander