Creating SSH key access to your Linux VPS

Typical SSH connection is with username and a password, without adding extra security that leaves the server open to brute force or access from anyone who can read your printed password in plaint text such as emails or a text file.

Having SSH key access to your server adds extra door/s of protection, plus instead of needing a password potential hackers now need a key and a password.

You can generate keys on your Linux server but for ease for beginners this will use windows and PuTTY Gen. PuTTY (popular SSH client) for windows can be downloaded here. In this package comes PuTTY Gen.

Generating your keys

Search for the PuTTY Gen.exe and open it

Click generate

Wave your mouse around in the area to speed up the process

You now have your key

Create/enter a password to protect the key file

Save the public and private key in safe place with a name you can recognize. I usually do hostnamePUBLIC and hostnamePRIVATE.

Add key to server

Open PuTTY.exe (or any SSH terminal) and connect to your server with the usual username and password.

Create the ~/.ssh directory with

mkdir -p ~/.ssh

Then create and open ~/.ssh/authorized_keys file with

nano ~/.ssh/authorized_keys

Here you want to paste the public key output from PuTTY Gen as seen by this highlighted top part (right click select all and then copy).

Once pasted into ~/.ssh/authorized_keys do ctrl + x then y and enter to exit and save.

Close the connection

Connect to server with key

Open up PuTTY and put in your servers hostname

On the list at the left find Auth under the SSH sub menu, click it.

Where it says Private key file for authentication click browse and select your private key you just generated.

Click session at the top of the list, where is says saved session enter a name (hostname) and click save.

To connect simply find the name you just used, click load and then open.

Enter your username and the password for the key file and you will now be logged in.

It is recommended to disable the normal username password login method after you have finished this key based authentication.