Loading SSH keys automatically on Windows (PuTTY)

Follow these steps if you use PuTTY and its authentication agent (Pageant) instead of Windows’ built-in OpenSSH client. For example, if you use SourceTree as your Git client, it comes with PuTTY (and Pageant) to use instead of OpenSSH.

Before you begin

Make sure you’ve installed the PuTTY suite, which includes Pageant. If it’s not installed, its download link is available at https://www.putty.org/.

Check if you have any existing SSH keys. Refer to the GitHub Docs article, Checking for existing SSH keys.

If you don’t have an SSH key:

1. Use the PuTTYgen application to generate a private/public key pair, saving it as private key. Refer to Using PuTTYgen, the PuTTY key generator in the PuTTY User Manual.
2. Add the new SSH key to your GitHub account, by following the GitHub Docs article, Adding a new SSH key to your GitHub account.

Procedure

Follow these steps to load keys and passphrases automatically on Windows:

1. Start Pageant from the PuTTY folder: Start-Menu > All Programs > PuTTY > Pageant
2. Find the Pageant icon in the system tray.
3. Right-click the Pageant icon in the system tray and select View Keys. The Pageant Key List window opens.
4. Click Add Key.
5. Use the File Explorer window to select your SSH key file to load. Make sure you select a file with a .ppk extension, then click Open.
6. If the key is passphrase-protected, enter your passphrase.
7. Make sure the key you selected is now listed in the Pageant Key List window. This key is now available to connect to any server during your PuTTY sessions.

You might have configured Git already to use PuTTY’s plink.exe program. To check if Git uses Pageant when using SSH keys:

1. Check if you have a GIT_SSH_COMMAND environment variable. If not, create it.
2. Set its value to the fully qualified path of PuTTY’s plink.exe file. By default, this location is "C:\Program Files\PuTTY\plink.exe". Important: If the path includes spaces, make sure you enclose the value in quotation marks.

To load private keys automatically on Startup:

1. Open the Start Menu and right-click Pageant.

2. Select More > Open file location. A File Explorer window opens.

3. Right-click Pageant and select Properties. The Pageant Properties window opens.

4. Update the Target field by appending the full paths of the private keys you want to load on startup. Separate each key with a space. Example:

     "C:\Program Files\PuTTY\pageant.exe" "C:\Users\user1\myKeys\privatekey.ppk"
   

5. Select Apply then select OK.

6. Test your configuration by opening a command line and running a git command in your repository, to make sure you can complete the operation without prompts for your passphrase.

When Pageant is running and you enter your passphrase, you can use the Unity Package Manager to fetch packages from that Git repository over SSH using your passphrase-protected SSH key.

The next time Pageant starts, it prompts you for the passphrase, if it’s passphrase-protected.

To load Pageant automatically when Windows starts, refer to the Microsoft Support article, Add an app to run automatically at startup in Windows 10.

Additional resources

• Loading SSH keys automatically on Windows (OpenSSH)
• Using passphrase-protected SSH keys with SSH Git URLs
• PuTTY User Manual