Setting up public key authentication

If your SSH client supports it, you can use public key authentication to log into WinSSHD. Our own recommended SSH client, Tunnelier, has strong support for public key authentication, as well as other authentication methods.

To set up public key authentication, you first need to generate a keypair on the client, or select one or more existing keypairs for use with WinSSHD. The procedure for generating the keypair depends on the client software being used:

• If you are using Tunnelier, click the link titled 'User keypair manager' in the Login tab. You can generate, edit, import and export keypairs in the dialog box that pops up.
• If you are using a different client, you need to follow its process for generating keypairs. For example, in OpenSSH, keypairs are generated using the ssh-keygen utility. Make sure to generate an SSH2 keypair (not SSH1). Use either the RSA or the DSA/DSS algorithm.

Once the keypair has been generated, you need to export the public key into a file that will be uploaded onto the server. The public key file can be either in the standard SSH2 public key format, or in the OpenSSH format. The exporting and importing process depends on the client being used:

• With Tunnelier, use Tunnelier's User Keypair Manager to export the public key in either format.
• If you are using a different client, you need to follow its process for exporting the public key into either the standard SSH2 format or the OpenSSH public key format. If you are using OpenSSH, the public key file can be exported from an existing keypair using the ssh-keygen utility (consult 'man ssh-keygen').

Once your public key file has been exported, transfer it to the machine where WinSSHD is installed, or the machine from which you manage WinSSHD remotely using Tunnelier. If you are exporting the public key from Tunnelier and you are also using Tunnelier to administer WinSSHD remotely, no transfer is necessary - use the WinSSHD Remote Control Panel. Open WinSSHD Settings and go to Access Control > Windows Accounts - or, if you are setting up public key authentication for a virtual account, Virtual Accounts. If an entry for the user you are configuring is not already present, add it. Now, click on the 'Keys' link and a key management window will open. Use the key management window to import the public key.