[SOLVED] VirtualBox RDP authentication issue

[D2b2426R5d]

Hi all,

I have Debian 10 running with few VirtualBox 6.0 instances. Each one of them have Remote Display option enabled (Oracle pack installed), so I can use RDP protocol to see desktop of each machine from my other PC. Each virtual machine have different port, everything works perfectly in my LAN network.

I need to grant access to these VMs to WAN network, open ports in the router. The thing is, VirtualBox doesn't have any working authentication method. In VM's Settings/Display/Remote Display menu, I can see Authentication Method: Null, External, Guest. Null works fine without any password, but External and Guest just can't connect when I use Remote Desktop Manager in my Windows, same with Windows built-in Remote Desktop Connection - it doesn't ask for correct username/password, but just fails after 5 seconds. I don't get to ask how to set up this username and password.

Anyone can share some ideas how to authenticate this over WAN? Maybe VirtualBox have some configuration option which I haven't seen? Or maybe I need to use some SSH, VPN tunneling or something?

[D2b2426R5d]

Solved - used DDNS on the router, SSH server with EdDSA key (no password) opened to the world, on client side: PuTTY SSH authenticated with EdDSA key, with SSH tunnel to transfer RDP traffic from remote server to a localhost, then RDP viewer to connect to localhost:port (PuTTY brings traffic to localhost), and it works perfectly over WAN. All RDP un-authenticated traffic is encapsulated within secure SSH tunnel brought to life by PuTTY, it can be done with standard GNU tools as well I believe, so other Linux and Macs can have it too.