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I am a linux noob trying to use john the ripper for a security class. I have John installed to usr/share/john and i have (I think) successfully used the unshadow command to unshadow the pw file and then move a copy of the unshadowed file to usr/share/john

 sudo /usr/sbin/unshadow /etc/passwd /etc/shadow > /tmp/crack.password.db
 sudo cp tmp/crack.password.db usr/share/john/crack.password.db

But when I try to run john crack.password.db, I get the following error message:

myName@ubuntu: usr/share/john$ sudo john crack.password.db
No "single crack" mode rules found in john.ini
  • When I open "John.ini" in a text editor, it is blank.

What does this message mean and how can I fix it?

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  • I ran into this issue too on ubuntu 12.10 ..
  • Yes, your use of unshadow is correct, but note that the location of the resultant file does not matter .. as long as you supply the correct path to the file when you run john.
  • It turns out that /etc/john/john.conf makes references to $JOHN
  • With the default apt install of john on ubuntu 12.10, $JOHN is /usr/share/john ..
  • /usr/share/john is also where the john.log, john.pot and the passwords list reside.

  • Fix: ln -s /etc/john/john.conf /usr/share/john.ini

  • The symlinked john.conf file has all the default config settings, including the 'single crack' switch.

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