On 16-11-17 09:56:00, David Howells wrote: > Petko Manolov <petkan@xxxxxxxxxxxx> wrote: > > > On 16-11-16 18:11:13, David Howells wrote: > > > Allow keys to be added to the system secondary certificates keyring during > > > kernel initialisation in an unrestricted fashion. Such keys are > > > implicitly trusted and don't have their trust chains checked on link. > > > > Well, I for one do not explicitly trust these keys. I may even want to > > completely remove or replace them. > > Fine be me. However, if you remove them all I would guess that you cannot > perform a secure boot. Maybe not on PC, but there's plenty of other architectures out there. What if i replace all UEFI keys with my own? > Note that it's to be expected that the keys being loaded from the UEFI > database cannot have their signatures checked - which is why they would have > to be implicitly trusted. For the same reason, the kernel does not check the > signatures on the keys compiled into the kernel image. I build all kernels that matter to me and i _do_ trust myself. Unfortunately i can't say the same for any corporation out there. Trusting a key because your vendor shipped the HW with it so that you have no way to verify the signature is pretty weak argument IMHO. However, I am also well aware that most people just don't care. :) > > > This allows keys in the UEFI database to be added in secure boot mode for > > > the purposes of module signing. > > > > The key import should not be automatic, it should be optional. > > You can argue this either way. There's a config option to allow you to turn > this on or off. Arguably, this should be split in two: one for the whitelist > (db, MokListRT) and one for the blacklist (dbx). I did not see the config option. There is one? Right now i can't decide whether whitelist should go along with blacklist or there should be separate options. I guess for whoever goes down this path it would make sense to use either both or none of them. > Further, possibly I should add an option that allows this to be restricted to > secure boot mode only. Please do. It doesn't make much sense otherwise. > > Same applies to the validation process. > > Depends what you mean by "the validation process"? The use of secure boot at > all? The checking of signatures on keys? Module signing? Nevermind. The keys signature can't be verified in the classic UEFI case. Petko -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
