Messages in this thread | | | From | David Howells <> | Subject | Re: [PATCH 4/9] KEYS: Allow unrestricted boot-time addition of keys to secondary keyring | Date | Thu, 17 Nov 2016 09:56:00 +0000 |
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Petko Manolov <petkan@mip-labs.com> 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.
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.
> > 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).
Further, possibly I should add an option that allows this to be restricted to secure boot mode only.
> 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?
David
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