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

Nayna
2021-08-27T20:45:33Z

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.

Thanks & Regards,

- Nayna