Installing SFTP/SSH Server on Windows using OpenSSH

Follow a generic guide for Setting up SSH public key authentication in *nix OpenSSH server, with the following difference:

• Create the .ssh folder (for the authorized_keys file) in your Windows account profile folder (typically in C:\Users\username\.ssh).1
• For permissions to .ssh folder and authorized_keys file, what matters are Windows ACL permissions, not simple *nix permissions. Set the ACL so that only a respective Windows account have a write access to the folder and the file (what is the default access level, if you create the folder and the file, while logged in using the respective account).

Before the first connection, find out fingerprint of the server’s ED25519 key by running .\ssh-keygen.exe -l -f "%ProgramData%\ssh\ssh_host_ed25519_key" -E md5 from the C:\Program Files\OpenSSH, as the Administrator (with PowerShell, use $env:ProgramData instead of %ProgramData%):

C:\Program Files\OpenSSH>.\ssh-keygen.exe -l -f "%ProgramData%\ssh\ssh_host_ed25519_key" -E md5
256 MD5:0d:df:0a:db:b4:e9:f1:08:d5:59:2b:91:8e:08:1c:78 martin@example (ED25519)

Start WinSCP. Login dialog will appear. On the dialog:

• Make sure New site node is selected.
• On New site node, make sure the SFTP protocol is selected.
• Enter your machine/server IP address (or a hostname) into the Host name box.
• Enter your Windows account name to the User name box. It might have to be entered in the format user@domain, if running on a domain.
• For a public key authentication:
  • Press the Advanced button to open Advanced site settings dialog and go to SSH > Authentication page.
  • In Private key file box select your private key file.
  • Submit Advanced site settings dialog with the OK button.
• For a password authentication:
  • Enter your Windows account password to the Password box.
  • If you Windows account does not have a password, you cannot authenticate with the password authentication (i.e. with an empty password), you need to use the public key authentication.
• Save your site settings using the Save button.
• Login using Login button.
• Verify the host key by comparing fingerprint with the one collected before (see above).

If you cannot authenticate to the server, and you are using Windows 10 Developer mode, make sure that your OpenSSH server does not conflict with an internal SSH server used by the Developer mode. You may need to turn off the SSH Server Broker and SSH Server Proxy Windows services. Or run your OpenSSH server on a different port than 22.

• Guide to Installing Secure FTP Server on Windows using IIS;
• Guide to uploading files to SFTP server;
• Guide to automating operations (including upload).