Installing “John the Ripper” – The Password Cracker

“John the Ripper” – is a fast password cracker. Its primary purpose is to detect weak Unix passwords.

Most likely you do not need to install “John the Ripper” system-wide.

Instead, after you extract the distribution archive and possibly compile the source code (see below), you may simply enter the “run” directory and invoke John from there.

Compiling “John the Ripper”

Step 1: Download the latest version of ““John the Ripper”” and its signature

$ wget http://www.openwall.com/john/g/john-1.7.9.tar.bz2
$ wget http://www.openwall.com/john/g/john-1.7.9.tar.bz2.sign
$ wget http://www.openwall.com/signatures/openwall-signatures.asc

Step 2: Confirm the signature

This is a safety measure as we are dealing with dangerous thing.

Install the public key:

$ pgp -ka openwall-signatures.asc

Check the signature:

$ pgp john-1.7.9.tar.bz2.sign john-1.7.9.tar.bz2
gpg: Signature made Wed 23 Nov 2011 01:38:48 PM CAT using RSA key ID 295029F1
gpg: Good signature from "Openwall Project <signatures@openwall.com>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: 0C 29 43 AE 1E CD 24 EA  6E 0C B6 EE F5 84 25 69

You will see the message similar to the above. Ignore the warning as long as it says Good signature from “Openwall Project … “.

The warning is normal, see http://www.kernel.org/signature.html for more details.

Step 3: Uncompress and compile the sources

$ tar xvfj john-1.7.9.tar.bz2
$ cd john-1.7.9/src/
$ make
To build John the Ripper, type:
make clean <system>
where SYSTEM can be one of the following:
linux-x86-64-avx         Linux, x86-64 with AVX (2011+ Intel CPUs)
linux-x86-64-xop         Linux, x86-64 with AVX and XOP (2011+ AMD CPUs)
linux-x86-64             Linux, x86-64 with SSE2 (most common)
***

Note the make target for your system and type:

$ make clean <system>

Where <system> is the appropriate make target. Alternatively, if your system is not listed, use:

$ make clean generic

If everything goes well, this will create the executables for John and its related utilities under “../run/”.

Alternatively, you may copy the entire “run” directory to anywhere you like and use John from there.

Now you can change directory to there and test John, like this:

$ cd ../run/
$ ./john --test
Many salts:	400332 c/s real, 400332 c/s virtual
Only one salt:	383795 c/s real, 391627 c/s virtual
---
Benchmarking: BSDI DES (x725) [32/32 BS]... DONE
Many salts:	13362 c/s real, 13388 c/s virtual
Only one salt:	13299 c/s real, 13299 c/s virtual
---
Benchmarking: FreeBSD MD5 [32/32 X2]... DONE
Raw:	9225 c/s real, 9225 c/s virtual
***

Installing “John the Ripper” on Ubuntu

Execute the next command to install “John the Ripper” on Ubuntu:

$ sudo apt-get install john

Installing “John the Ripper” on CentOS/RHEL

Execute the next command to install “John the Ripper” on CentOS/RHEL:

$ yum install john

5 Replies to “Installing “John the Ripper” – The Password Cracker”

  1. Cant we directly do sudo apt-get install john for installing john the ripper in ubuntu?

    1. Yes, we can. But there is no guarantee that the john’s version from repository is the latest one. And actually there is no need to install this tool system-wide as it can be compiled and run from a standalone directory – sometimes this is very convenient, i guess, as if the john is no more needed you just delete the directory without leaving any traces in the system

  2. “john” doesn’t exist in RHEL 6/7 yum repos. Also not in centos 7.
    sudo yum -y install john

    Setting up Install Process
    No package john available.
    Error: Nothing to do

  3. yo, ps-ax here, just an advise, the latest version of john atm is 1.8 so the download links for wget have changed to
    : http://www.openwall.com/john/j/john-1.8.0.tar.gz << for the ripper itself
    http://www.openwall.com/john/j/john-1.8.0.tar.gz.sign << signature

    see you! and helpfull article man, enjoy it.!

  4. roott-K73SJ roott # pgp john-1.7.9.tar.bz2.sign john-1.7.9.tar.bz2
    gpg: no valid OpenPGP data found.
    gpg: the signature could not be verified.
    Please remember that the signature file (.sig or .asc)
    should be the first file given on the command line.
    WARNING: Can’t find the right public key– can’t check signature integrity.
    roott-K73SJ roott #

Leave a Reply