I'm designing a security sensitive setup for a client. The situation is as follows:
Sensitive information has to be stored on a server that might be accessed by unauthorized personnel. There is no way to secure the hardware in a way that it is 100% secure.
Here my approach:
I'm encrypting the root machine with cryptsetup/luks, then I'm encrypting an image with cryptsetup/luks and mounting it to be a virtual machine's harddrive. The virtual machine has again an encrypted root FS.
Now I want to prevent anyone from accessing the machine's hardware while it is running. I want to detect unknown devices that are plugged into it, like a USB-thumbdrive or a Firewire device, etc.
Is there a way to detect unknown devices elegantly in udev? So far i've only found ways to define actions for devices I know. But I want to define an action for when an unknown device connects.
Thanks for your input.