Re: [PATCH v4 00/12] Enroll kernel keys thru MOK

Jarkko Sakkinen
2021-09-01T04:34:46Z

On Fri, 2021-08-27 at 16:44 -0400, Nayna wrote:
> On 8/25/21 6:27 PM, James Bottomley wrote:
> > On Thu, 2021-08-26 at 01:21 +0300, Jarkko Sakkinen wrote:
> > > On Tue, 2021-08-24 at 10:34 -0400, Mimi Zohar wrote:
> > > > > > > Jarkko, I think the emphasis should not be on "machine" from
> > > > > > > Machine Owner Key (MOK), but on "owner". Whereas Nayna is
> > > > > > > focusing more on the "_ca" aspect of the name. Perhaps
> > > > > > > consider naming it "system_owner_ca" or something along those
> > > > > > > lines.
> > > > > > What do you gain such overly long identifier? Makes no sense.
> > > > > > What is "ca aspect of the name" anyway?
> > > > > As I mentioned previously, the main usage of this new keyring is
> > > > > that it should contain only CA keys which can be later used to
> > > > > vouch for user keys loaded onto secondary or IMA keyring at
> > > > > runtime. Having ca in the name like .xxxx_ca, would make the
> > > > > keyring name self-describing. Since you preferred .system, we can
> > > > > call it .system_ca.
> > > > Sounds good to me. Jarkko?
> > > >
> > > > thanks,
> > > >
> > > > Mimi
> > > I just wonder what you exactly gain with "_ca"?
> > Remember, a CA cert is a self signed cert with the CA:TRUE basic
> > constraint. Pretty much no secure boot key satisfies this (secure boot
> > chose deliberately NOT to use CA certificates, so they're all some type
> > of intermediate or leaf), so the design seems to be only to pick out
> > the CA certificates you put in the MOK keyring. Adding the _ca suffix
> > may deflect some of the "why aren't all my MOK certificates in the
> > keyring" emails ...
>
> My understanding is the .system_ca keyring should not be restricted only
> to self-signed CAs (Root CA). Any cert that can qualify as Root or
> Intermediate CA with Basic Constraints CA:TRUE should be allowed. In
> fact, the intermediate CA certificates closest to the leaf nodes would
> be best.
>
> Thanks for bringing up that adding the _ca suffix may deflect some of
> the "why aren't all my MOK certificates in the keyring" emails.

What the heck is the pragamatic gain of adding such a suffix? Makes
zero sense.

/Jarkko