I have the following problem. Our product integrates with LED signs of a certain manufacturer. Communication with these devices is via HTTP (they contain a web server for admin UI and a web service). The device does not offer any authentication methods, which means if you can connect to the device via TCP network, you have full access to the device.
Our sales team and customers really like these signs due to their versatility and want them. The manufacturer is not much concerned about lack of security and not in a hurry to add any (HTTPS, user name + pw login, etc).
I am wondering if there are small devices that could be "added" to each LED sign to enforce encrypted and authenticated communication with those signs. Here is what I have in mind. The device is physically attached to a sign (inside or outside. The device has two Ethernet ports. One port gets connected to the LED sign's Ethernet port, the other to the Intranet ethernet port in the wall. The main server that controls the LED signs can now establish secure communication with those devices (VPN?) and all HTTP communication to and from the LED signs is securely tunneled through those devices.
I searched the Internet for quite a while and couldn't find any such device, possibly because I don't know what you would call such a device.
One more constraint: The main server that controls the LED signs runs Windows 2008 R2 and higher, so whatever software runs on the main server to enable those tunnels needs to run on Windows.