SOLVED john the ripper

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SOLVED john the ripper

Postby purplepenguin » Mon Sep 24, 2012 8:25 pm

After reading the articles by James Litton "Passwords a better strategy" in issue 162 and Ben's "Hack a server" article in issue 163 I wanted to see how secure my passwords are on my home server.

I installed JTR on my main Mint PC and copied the shadow file from the server (which is running Ubuntu 12.04 server). to a file on in my home directory called pass.txt. I ran JTR overnight and it failed to crack any of the 3 user passwords yipee I thought my passwords must be fairly strong.

I was nosing about in /etc/john/john.conf and saw this section

Code: Select all
Incremental modes
[Incremental:All]
File = $JOHN/all.chr
MinLen = 0
MaxLen = 8
CharCount = 95

[Incremental:Alpha]
File = $JOHN/alpha.chr
MinLen = 1
MaxLen = 8
CharCount = 26

[Incremental:Digits]
File = $JOHN/digits.chr
MinLen = 1
MaxLe]n = 8
CharCount = 10

[Incremental:Alnum]
File = $JOHN/alnum.chr
MinLen = 1
MaxLen = 8
CharCount = 36

[Incremental:LanMan]
File = $JOHN/lanman.chr
MinLen = 0
MaxLen = 7
CharCount = 69


Does the MaxLen=X part mean that JTR cannot crack passwords over this length? and can I just change this value to a larger one say 20?

The shortest password in use on my server is 12 characters long all lowercase and I was wondering if the reason JTR failed to crack any of them is due to this MaxLen parameter.

Thanks for any insight

Lee
Last edited by purplepenguin on Mon Sep 24, 2012 10:00 pm, edited 1 time in total.
purplepenguin
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Posts: 130
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Postby purplepenguin » Mon Sep 24, 2012 9:59 pm

OK I seem to have answered my own question those parameters only affect the incremental mode not the wordlist attack. to make the MaxLen larger I would need to recompile John.
purplepenguin
LXF regular
 
Posts: 130
Joined: Wed Oct 05, 2011 2:19 pm
Location: Blissfully at the Command Line


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