How to harden RDP with SSH from Linux to Windows

I need help and a step-by-step guide how to setup SSH tunneled RDP from my Ubuntu (18.04) laptop to my Windows 10 desktop both across LAN and WAN. I have a hunch what to do in theory, but not in practice. I would prefer to use any FOSS solutions if possible.

I have OpenSSH server installed in my Windows 10 and in Ubuntu I could use e.g. Remmina as RDP/SSH client. Remmina seems to have SSH functionality also included. While installing OpenSSH server in Windows and following Microsoft’s guide found here:

I encountered problem when trying to execute the following command: Install-Module -Force OpenSSHUtils -Scope AllUsers

Command fails with the following error code: The module ‘OpenSSHUtils’ cannot be installed or updated because the authenticode signature of the file ‘OpenSSHUtils.psd1’ is not valid.

While trying to troubleshoot this via Google I found out that it indicates that Windows OpenSSHUtils is deprecated. If there is no valid OpenSSHUtils or I can’t continue with Windows OpenSSH server, then I don’t mind using other SSH server solutions.

I’ve been using and satisfied with Bitvise SSH server/client solution found in Windows only, but haven’t found any cross-platform solution yet. I would be very grateful for any found recommendation or solution, especially if they are FOSS. Thank you very much!!