MoonPoint Support Logo


Shop Amazon Warehouse Deals - Deep Discounts on Open-box and Used ProductsAmazon Warehouse Deals

Advanced Search
Sun Mon Tue Wed Thu Fri Sat

Fri, Jun 28, 2013 9:29 pm

SSH Port Forwarding for VNC under Chrome OS

If you need a Virtual Network Computing client for a Chromebook, such as the one manufactured by Acer, RealVNC provides a free one that is available through the Google Chrome Web Store. For details on the app, see VNC® Viewer for Google Chrome™.

When I used it to connect to a Mac OS X system, I was warned that the connection would not be encrypted.

Unencrypted Connection

This connection will not be encrypted. Your authentication credentials will be transmitted securely, but all subsequent data exchanged while the connection is in progress may be susceptible to interception by third parties.

That's not a significant concern for me when both systems are on a Local Area Network (LAN) I control, but I normally tunnel VNC connections through an SSH connection when connecting over the Internet to ensure transmissions are encrypted.

Chrome OS on a Chromebook contains A Secure Shell (SSH) client application. To access it, hit the Ctrl-Alt-T keys simultaneously, which will open a terminal window as a tab in the Chrome browser. Type ssh at the "crosh>" prompt to access the ssh client.

Welcome to crosh, type 'help' for a list of commands.
crosh> ssh

Within the ssh application, typing help will show you a list of the available commands.

ssh> help
connect - connect
dynamic-forward port - dynamic socks proxy (-D)
forward port:host:port - static port forward (-L)
help - this
host <hostname> - remote hostname
key <file> - sets private key to use (-i)
nocmd - don't execute command (-N)
port <num> - port on remote host (-p)
server-alive-interval <num> - set ServerAliveInterval option
exit - exit ssh subsystem
user <username< - username on remote host
Note that this program can only bind local ports in the range
8000-8999, inclusive.

If you wish to encrypt a Virtual Nework Computing (VNC) connection by tunneling it through an SSH connection, you will need to specify a port from 8000 to 8999 as the port to be used for forwarding the VNC traffic when using SSH under Chrome OS. You can do so using a forward command such as the following:

crosh> ssh
ssh> user JDoe
ssh> host
ssh> forward 8000:
ssh> connect

Then using the RealVNC client for Chrome OS, you can specify or localhost::8000 as the address through which to establish the VNC connection. You could also have used forward 8000:localhost:5900 for the SSH forwarding command. The address is the localhost address and with the port number of 8000 tells VNC to try establishing the VNC connection by connecting to port number 8000 on the system on which VNC is running, i.e., the Chromebook. Because there is an SSH tunnel through that port, SSH will route any traffic to TCP port 8000 through its connection to port 5900 on the remote system.

You will still get the warning from the VNC Viewer about transmissions not being encrypted when you tunnel the traffic through the SSH tunnel, but you no longer have to worry about the warning, since the traffic is going through an encrypted SSH tunnel. The VNC Viewer does not know that its transmissions are going through an encrypted tunnel; it only knows that it isn't performing any encryption.

[/os/chrome] permanent link

Fri, Jun 28, 2013 1:06 pm

Remote Screen Sharing using VNC on a Mac OS X System

A Mac OS X system that is functioning as a Virtual Network Computing (VNC) server can be remotely accessed using VNC client software that comes with the OS X operating sytem, which will allow you to see what appears on the screen of the system remotely and control that remote system just as if you were sitting at the system using its keyboard and mouse.

[ More Info ]

[/os/os-x] permanent link

Valid HTML 4.01 Transitional

Privacy Policy   Contact

Blosxom logo