In this segment we are going to talk about using john for security.
sudo apt-get install build-essential
sudo apt-get install libssl-dev
(optional) sudo apt-get -y install yasm libgmp-dev libpcap-dev pkg-config libbz2-dev
(optional) sudo apt -y install zlib1g-dev
apt-get install git -y
mkdir /root/src
cd ~/src
git clone git://github.com/magnumripper/JohnTheRipper -b bleeding-jumbo john
cd ~/src/john/src
./configure && make -s clean && make -sj4
http://openwall.info/wiki/john/tutorials/Ubuntu-build-howto
(also https://linuxreference.wordpress.com/2019/06/07/howto-install-john-the-ripper-in-ubuntu-18-04/)
(also http://insidetrust.blogspot.com/2011/01/password-cracking-using-john-ripper-jtr.html )
(additionally: http://pentestmonkey.net/cheat-sheet/john-the-ripper-hash-formats)