Howto

SFTP using SSH2: Key based authentication

For SFTP using SSH2, FileZilla utilises the excellent PuTTY tools. To allow the use of RSA / DSA key files with Filezilla, you'll need to download two more tools from PuTTY: Pageant and (assuming your key file isn't already in PPK format) PuTTYgen.

If your key file is already in PuTTY's PPK format you can skip this paragraph. However if your key is in OpenSSH format, you first need to convert it to PuTTY's PPK format. To do this, launch PuTTYgen and from the "Conversions" menu, select the "Import key" option. Select your key and follow the prompts to enter your passphrase. Save your private key.

Now run Pageant. In your system tray, you'll see the Pageant icon appear. Right-click the icon and select "Add Key" and select your private key (PPK) file. Follow the prompt to enter your passphrase and you're done.

Now simply launch FileZilla and connect to your server using SFTP using SSH2 with a username and an empty password. Don't forget to close pageant when you're done.

I'm not sure how well this'll work on systems where you're forced to not save your password, but after selecting "Don't save password" in the site manager for my server, I could exit the site manager by pressing "cancel" on the password dialog and then "Save and Exit". When you select your site from the list, again press "cancel" and it'll still attempt to connect.

As you may or may not know, FileZilla can be easily carried around on portable media such as a USB stick and used from any PC. This also applies to the PuTTY tools, so if you stick Pageant and your PPK key file on to, for example, a USB stick, you can now access your server from any Windows PC.