This is a super-fast blog to show how to crack sshkeys with JohnTheRipper from Kali VM.

Create a key

ssh-keygen

(Note there are options for doing this but for now we will use the defaults)

Clone Jumbo John (it’s not in Kali by default only the normal JTR is)

git clone https://github.com/openwall/john.git

cd ~/john/run

sudo apt update

cd john

cd src

sudo apt install git build-essential libssl-dev zlib1g-dev -y

./configure && make

cd ~/john/run

python ssh2john.py

python ssh2john.py ~/.ssh/id_rsa

python ssh2john.py ~/.ssh/id_rsa > sshhash.txt

cd ~/john/run

./john ~/john/run/sshhash.txt –wordlist=passwords.txt

and there we have it a very quick post and a cracked SSH key! remember hack for good, learn all the things and be safe!