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Putty is a popular SSH client for Windows that allows you to connect to remote servers and execute commands. However, every time you connect to a server, you have to enter your password, which can be tedious and insecure. In this blog post, I will show you how to make passwordless putty using public key authentication.

Public key authentication is a method of verifying your identity without using a password. Instead, you generate a pair of keys: a private key that you keep on your computer, and a public key that you upload to the server. When you connect to the server, putty will use your private key to prove that you are the owner of the public key, and the server will grant you access.

To make passwordless putty, you need to follow these steps:

1. Generate a key pair using puttygen. Puttygen is a tool that comes with putty and can be found in the same folder. To launch it, double-click on puttygen.exe. You will see a window like this:


Click on the Generate button and move your mouse randomly over the blank area to create some randomness. After a few seconds, you will see your key pair generated. You can enter a passphrase to protect your private key, but this is optional. You can also change the key type and size, but the default settings are fine for most cases.

2. Save your private key and copy your public key. Click on the Save private key button and choose a location and name for your private key file. It will have a .ppk extension. Then, select all the text in the Public key for pasting into OpenSSH authorized_keys file box and copy it to your clipboard.

3. Upload your public key to the server. Connect to your server using putty as usual, and enter your password when prompted. Then, open a terminal and type the following command:

Replace <paste your public key here> with the text you copied from puttygen. This will append your public key to the authorized_keys file in your .ssh folder. If the file or folder does not exist, it will be created automatically.

4. Configure putty to use your private key. Close your current putty session and open a new one. Before you connect to the server, go to Connection > SSH > Auth in the left panel and click on the Browse button under Private key file for authentication. Locate and select your private key file that you saved earlier.


5. Connect to the server without password. Now you are ready to connect to the server using passwordless putty. Just enter the host name or IP address of the server and click on Open. You will not be asked for a password anymore, and you will be logged in automatically.


Congratulations! You have successfully made passwordless putty using public key authentication. This will make your SSH connections more convenient and secure. You can repeat this process for any other servers that you want to access with passwordless putty.