How do I set up passwordless login in PuTTY?

Overview

This article explains how to set up passwordless login with PuTTY. Make sure you have first configured PuTTY before proceeding with this article.

Configuring passwordless login

1. Open the puttygen.exe file you downloaded when configuring PuTTY. You’ll use this to create your private/public keypair.
2. In the PuTTY Key Generator box, make sure the radio button at the bottom is selected for ‘RSA’.

   

3. Click the Generate button.
4. Move your mouse around the box to help generate the keys.

   Once the key is created, a new pop-up box appears:

   

   

   • On the bottom right, there are buttons named Save public key and Save private key – save both to your computer.
   • When you save the public key, name it something like "dreamhostpublickey". Do not manually add the extension as that isn’t necessary.
   • When you save the private key, name it something like "dreamhostprivatekey" and be sure to save it in a secure location on your computer. Again, do not manually add the extension as that isn’t necessary.
   • When saving, you are prompted with a message about a passphrase.

     

     Click Yes to save without a passphrase.
5. Upload the public key you just created to your DreamHost users home directory. You can use an FTP client such as Filezilla to do this.
6. Log into your DreamHost web server through PuTTY.
7. In your users /home directory, create an /.ssh directory by running this command:

   [server]$  mkdir .ssh

8. While still in your user's home directory, append the public key you just uploaded to a new file named ‘authorized_keys’ which is located in the /.ssh directory by running this command:

   [server]$  ssh-keygen -i -f dreamhostpublickey >> ~/.ssh/authorized_keys

   This appends the dreamhostpublickey you uploaded from your home computer into a new file named ‘authorized_keys’. Just make sure the name of the public key file in the command is the name of the file you uploaded.

9. Adjust permissions by running this command:

   [server]$  chmod go-rwx ~/.ssh/authorized_keys

   Then remove the original dreamhostkey.pub file:

   [server]$  rm dreamhostpublickey

   Now the key sit on the server (protected from access by others)

10. Log out of PuTTY and start the program up again.
11. When the program restarts, open the configuration box and click the ‘Connection' > 'Data’ category on the left.

    

12. Enter your DreamHost SHELL username in the first field which is named ‘Auto-login’ username.

    

13. In the same configuration box, click ‘Connection' > 'SSH' > 'Auth’.
14. Click the Browse button and navigate to the location on your computer where you saved your dreamhostprivatekey file.

    

15. On the configuration box, click the 'Session' category and enter the following:
    • Host Name: yourserver.dreamhost.com (This is your DreamHost servername)
    • Port: 22
    • Connection Type: SSH
    • Saved Session: Enter a new name
16. Click the Save button.
17. Open PuTTY and click the new saved session you created for the passwordless login, then click the Open button. You are logged in without a password prompt.

See also