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authorized_keys


Dear Diary,
Today I learned how to configure ssh to login to a remote machine without a password!
So, SSH uses public key cryptography (i.e. that chapter that bored you to death in the Security+ textbook). Which means that is uses a private key and public key to create a connection (does that jog your memory?).
First, type this command in the attacking computer to generate a key pair:
$ ssh-keygen
This will output the following:



Then navigate to your /<username>/.ssh folder...



And you'll see these files. id_rsa is your private key and id_rsa.pub is the public key (which is why it ends in .pub :)

 
Now, navigate to the /home/<username>/.ssh/ directory on the target machine and copy and paste the contents of id_rsa.pub to to the authorized_keys file. It looks something like this:



Then, return your attacking box and type these commands: 
# ssh-add
# ssh -i id_rsa <username>@<remote ip>
And voila! You have just exploited authorized_keys to get a shell!






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