We would like to provide a flash drive to a client, that they can boot to, which includes a read-only operating system of our own customization, probably Linux. Every boot, it starts from clean slate.
With the current setup, a person with physical access to the drive could switch the write protect switch, inject some code that calls back their own server, flip the switch back, and we may or may not be able to detect that the code was injected, when booting, because once booted, the OS could be tampered to hide the injected files from boot integrity checksumming, or modify the checksumming routine not to check the injected files.
What I would like is to put a password on the flash drive, so the write protect can only be disabled if we enter the password.
- Is there such a device with the additional hardware/firmware countermeasure I refer to? What would it be called, how could I find this type of product?
- For an operating system that is required to contact our server equipment, do you have an alternate suggestion of how to detect and/or prevent operating system tamper such as this?