john-users - brute force attack of an Unix crypt

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

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

Date: Mon, 27 Jun 2011 02:06:27 +0300
From: Martin T <m4rtntns@...il.com>
To: john-users@...ts.openwall.com
Subject: brute force attack of an Unix crypt

Checking the CPU usage of my 4-core Xeon X3220(4x 2.4GHz) processor, I
found out, that I had started an brute force attack at the beginning
of February(!). I had dedicated an entire CPU core for this process:

UID        PID  PPID  C STIME TTY          TIME CMD
root      7262  6307 99 Feb05 pts/9    271-18:45:57 john
--incremental=All8 --session=8 unix_crypt.txt

.."unix_crypt.txt" looks like this:

root@...tin-desktop:~# cat unix_crypt.txt
martin:HkbEPpfxBdH3k
root@...tin-desktop:~#

..and incremental mode part is specified in /etc/john/john.conf:

[Incremental:All8]
File = /usr/share/john/all.chr
MinLen = 8
MaxLen = 8
CharCount = 95

I remember that I really used letters, numbers and special
characters(8 characters in total) in order to generate this crypt
file. I even found the terminal where I started this command and if I
pressed enter few times, following was printed to the terminal:

guesses: 0  time: 139:15:12:09  c/s: 930654  trying: l5rBse_N - l5rBsil$
guesses: 0  time: 141:15:32:12  c/s: 929241  trying: 1doccLl4 - 1doccLur
guesses: 0  time: 141:15:32:15  c/s: 929241  trying: 1dau4qf! - 1dau4qwp
guesses: 0  time: 141:15:34:21  c/s: 929241  trying: 1jeTL x8 - 1jeTL e#
guesses: 0  time: 141:18:48:12  c/s: 929072  trying: 2kageA3z - 2kageACs

How much longer it might take to decrypt this Unix crypt?

regards,
martin