Setup SSH

Source: https://winscp.net/eng/docs/guide_windows_openssh_server

• In Settings app, go to Apps > Apps & features > Manage optional features.
• Locate “OpenSSH server” feature, expand it, and select Install.
• Run:

New-NetFirewallRule -Name sshd -DisplayName 'OpenSSH SSH Server' `
    -Enabled True -Direction Inbound -Protocol TCP -Action Allow `
    -LocalPort 22 -Program "C:\System32\OpenSSH\sshd.exe"

• Go to Control Panel > System and Security > Administrative Tools and open Services. Locate OpenSSH SSH Server service.
• If you want the server to start automatically when your machine is started: Go to Action > Properties. In the Properties dialog, change Startup type to Automatic and confirm.
• Start the OpenSSH SSH Server service by clicking the Start the service.

Enable Key Authentication

Source: https://github.com/PowerShell/Win32-OpenSSH/wiki/Security-protection-of-various-files-in-Win32-OpenSSH

For administrator user:

cd C:\ProgramData\ssh\
New-Item administrators_authorized_keys
# Copy-paste public key (e.g. ~/.ssh/id_rsa.pub) entry into this file
icacls administrators_authorized_keys /inheritance:r
icacls administrators_authorized_keys /grant SYSTEM:`(F`)
icacls administrators_authorized_keys /grant BUILTIN\Administrators:`(F`)