|https://launchpad.net/~ayers (ayers [launchpad.net]) wrote in mjg59,|
Let's assume, that users want to insure that their boot sequence has been verified and signed by the trusted vendor of their choice, yet still keep themselves in control to override the upstream signatures. How should that be set up?
There could be some centrally maintained list of 'root' keys that each hardware vendor imports as the default list. The signing format must be updated to allow multiple signatures on binaries. That way, the user can choose which vendor keys to trust and distributions can decide to have there code signed by multiple vendors who choose to take responsibility for the security of the code. The UEFI implementation must provide a simple application to manage those keys. This simple applications must provide a consistent user experience over all UEFI implementations. It would probably be best to provide this simple application in the reference implementation. The management must allow the user to trust and distrust keys, to remove keys and to add keys from external media and to prioritize keys in a list to resolve potential conflicts of binaries whose signatures have been revoked by some vendors but not by others. There should probably also be an easy way to restore the default list. Yet there must be another application for the operating systems for every day users to generate there own key and install it on external media to add it to the UEFI key management, so that they can position their own key on top and override the vendor keys. It should also be trivial for the user to sign boot loaders, kernels, drivers they trust.
The major distributions could use a single organization like the Linux Foundation to manage a root key in the default list. Yet it would allow other distributions to distribute their own root key independently via their websites. The user would store them on external media to install them via the UEFI key management. This should allow the user to control the system while using secure boot to keep whatever integrity secure boot offers.