How do I set up passwordless login in PuTTY?

Setting up passwordless login

The following are instructions on how to set up passwordless login with PuTTY.

1. Open the puttygen.exe file you downloaded previously. 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 ‘SSH-2-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.
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. 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 in your users /home directory:

   [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 is the name you uploaded it as.

9. Adjust permissions by running this command:

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

   Then remove the original dreamhostkey.pub file:

   [server]$  rm dreamhostpublickey

   Now the keys 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
    • Port: 22
    • Connection Type: SSH
    • Saved Session: Enter a new name
16. Click the Save button.
17. Open pageant.exe on your home computer to authenticate automatically.
    • It may appear as an icon on the bottom right of your toolbar.
    • Right click on that icon and choose ‘Add Key’.
18. Navigate to where you stored your private key on your computer and add the private key file.
19. Open PuTTY and click the new saved session you created for the passwordless login. You are logged in without a password prompt.

See also

• How do I configure PuTTY?
• PuTTY binary files
• Troubleshooting PuTTY
• How to configure passwordless login in Mac OS X and Linux