John the Ripper Docker

This Docker image contains John the Ripper compiled with support for OpenCL. Due to the OpenCL Support you may run it with nvidia-docker.

The prebuilt image is available at Docker Hub.

Starting the container

The best way to run the cracker is like this:

nvidia-docker run --rm -ti -v /tmp/in:/in -v /tmp/out:/home/john knsit/johntheripper /in/crack.sh

• mount an in volume to pass in the password file, optionally a wordlist and a script to run
• mount an out volume to the home-folder to get the results
• pass the path to the mounted script as param to the entrypoint

Script

The script to run JtR is a little bit hacky. It's necessary (for some reason) to copy the john.conf file from /etc/john to the hidden .john folder in the home directory of the current user. Otherwise JtR won't run with an error

fopen: $JOHN/john.conf: No such file or directory

Sample script:

#!/bin/bash
[[ -d ~/.john ]] || mkdir ~/.john
[[ -f ~/.john/john.conf ]] || cp /etc/john/john.conf ~/.john/
john --format=sha512crypt-opencl --wordlist=/in/wordlist /in/intranet-unshadowed