Lab: John the Ripper.

The goal of this step is to setup for the lab.

Step 3: John Operation

Remember there is documentation for john.
Run john on the password file
- john comes with an unshadow utility
  - This will make the password file usable by john.
- Run this
  - sudo unshadow /etc/passwd /etc/shadow > myPass
- Look at myPass
  - Each line represents a user.
- Run john on this file
  - john myPass
  - Notice this returns almost instantly. Read the text john produces.
  - Run john myPass --show
  - This tells you that john has figured out the passwords for bob and alice.
  - This is not a surprise as the first pass of john is to try information from the password file.
- If you run john again, it will not do anything
  - John is designed as a long term continuous operation.
  - It saves a history of the passwords it has found
  - Look at the files in ~/.john
    - ls ~/.john
    - less ~/.john/john.log
    - less ~/.john/john.pot
In the directory ~bob/passwordCode is a file myCrypt which will create a fake password file entry given a user name and a password.
- try ../passwordCode/myCrypt user1 hello
- As we saw in the pwnkit lab, we can redirect output to a file with the > and >> operators.
- try ../passwordCode/myCrypt user1 hello >> newPassFile
  - Look at the contents of newPassFile
- run john newPassFile
  - This will return instantly so
  - run john --show newPassFile

Using the command above add a few more entries to newPassFile.

Username	Password
user2	hell0
user3	hello1
user4	passwords
user5	are
user6	fun
user7	to
user8	crack
kirk	ncc1701
pickard	ncc1701d

Now try running john
- john newPassFile
- At any time, you can press a key to see what john is working on.
  - This includes
    1. The number of passwords guessed
    2. The length of time John has been running (D-H-M-S)
    3. Percent done on the current pass.
    4. Which pass it is on
    5. Guess per second rate
    6. Passwords per second
    7. Crypts per second.
    8. The current words being tested.
- Note that within a minute or two John has guessed most of the passwords.
- We can help John out by giving it a different dictionary.
- Try john --wordlist=lower newPassFile
  - This tells john to use the file lower to check.
  - Note that in a few minutes the other two passwords are found!
  - You don't need to wait for the entire process to complete.
Strangely, to is the hardest of this set to crack, but that is just an accident of the alphabet.
- At 400 PPS, it will take no longer than 12 minutes to find that one however.

This will not work well on your simulated machine, but it will work.

John works in parallel mode.
Start by removing the .john directory in bob's home directory
- Remember, john caches the passwords it has found in this directory
- By removing this directory, you force john to start over.
Be careful and do this right
- rm -rf ~/.john

Start john again but this time

john newPassFile --wordlist=lower --fork=2
Try pressing the space bar now and monitor John's progress.
You don't need to wait for the entire process to complete.

On Mirkwood, with 4 real cores, it took nearly four minutes to find all these passwords

[bennett@mirkwood pass]$ time john newPassFile --wordlist=lower --fork=4
Created directory: /home/bennett/.john
Loaded 10 password hashes with no different salts (crypt, generic crypt(3) [?/64])
Node numbers 1-4 of 4 (fork)
Press 'q' or Ctrl-C to abort, almost any other key for status
are              (user5)
crack            (user8)
fun              (user6)
hello            (user1)
passwords        (user4)
to               (user7)
4 3g 0:00:03:49 100% 0.01309g/s 323.7p/s 323.7c/s 2684C/s zoologies..zyzzyva
1 1g 0:00:03:49 100% 0.004355g/s 323.1p/s 323.1c/s 2970C/s zoologist..zyzzyvas
Waiting for 3 children to terminate
3 2g 0:00:03:49 100% 0.008707g/s 323.0p/s 323.0c/s 2882C/s zoologize..zythum
2 0g 0:00:03:51 100% 0g/s 320.1p/s 320.1c/s 3201C/s zoologists..zythem
Use the "--show" option to display all of the cracked passwords reliably
Session completed

real    3m51.805s
user    15m18.599s
sys     0m0.037s