How to Convert a .pem Private Key to a .ppk Private Key Using PuTTY

When using AWS services like EC2 or Lightsail, SSH keys are essential for secure login to your instances. However, if you’re using PuTTY as your SSH client, it requires a .ppk (PuTTY Private Key) format for authentication. AWS provides .pem keys by default, so converting them to .ppk is a crucial step. This guide will walk you through converting a .pem private key to a .ppk key using PuTTY Key Generator (PuTTYgen), making it ready for use with PuTTY or any other compatible SSH client.

Prerequisite:

• Download and install PuTTY ( https://www.putty.org )
• Ensure your .pem key is saved on your Desktop (or another known location)

Step-by-Step Guide:

Step 1: Locate your .pem private key file that you downloaded from AWS when you created your Security Key Pair.

Step 2: Open PuTTY Key Generator (PuTTYgen).

Step 3: In PuTTY Key Generator, go to the drop-down menu, select “Import Key”, and click on “Load” to import the .pem file into PuTTYgen.

Step 4: Once the .pem private key has been imported, it will be displayed in the key section.

Step 5: Click on the “Save private key” button to convert and save the .ppk private key.

Step 6: A pop-up will appear asking if you want to save the key without a passphrase. Click “Yes” to proceed without a passphrase (for this guide). Alternatively, you can click “No” if you want to add a passphrase for extra security.

Step 7: PuTTY Key Generator will now save the .ppk file to your selected location.

Extra Notes:

• Security Consideration: While omitting a passphrase makes login more convenient, it reduces security. For better protection, consider adding a passphrase in Step 6 by clicking “No” and entering your desired passphrase.

• Using PuTTY for SSH Login: Once you have your .ppk file, you can use it with PuTTY to log in to your AWS instance by navigating to the “Auth” section under SSH in PuTTY and loading your .ppk file.

• Backup: Always keep a backup of your original .pem and .ppk keys in a secure location.

Conclusion:

By following these steps, you’ve successfully converted your .pem private key to a .ppk private key, allowing you to use PuTTY or another SSH client that requires .ppk files. This key conversion process is essential for securely accessing your AWS instances and ensuring a smooth, secure login process. If you ever need to reconnect or use a new machine, you now have the necessary file format to do so.