Re: [PATCH] integrity: powerpc: Do not select CA_MACHINE_KEYRING

[Jarkko Sakkinen]

On Tue Sep 12, 2023 at 10:41 AM EEST, Michal Suchánek wrote:
> On Mon, Sep 11, 2023 at 11:39:38PM -0400, Nayna wrote:
> > 
> > On 9/7/23 13:32, Michal Suchánek wrote:
> > > Adding more CC's from the original patch, looks like get_maintainers is
> > > not that great for this file.
> > > 
> > > On Thu, Sep 07, 2023 at 06:52:19PM +0200, Michal Suchanek wrote:
> > > > No other platform needs CA_MACHINE_KEYRING, either.
> > > > 
> > > > This is policy that should be decided by the administrator, not Kconfig
> > > > dependencies.
> > 
> > We certainly agree that flexibility is important. However, in this case,
> > this also implies that we are expecting system admins to be security
> > experts. As per our understanding, CA based infrastructure(PKI) is the
> > standard to be followed and not the policy decision. And we can only speak
> > for Power.
> > 
> > INTEGRITY_CA_MACHINE_KEYRING ensures that we always have CA signed leaf
> > certs.
>
> And that's the problem.
>
> From a distribution point of view there are two types of leaf certs:
>
>  - leaf certs signed by the distribution CA which need not be imported
>    because the distribution CA cert is enrolled one way or another
>  - user generated ad-hoc certificates that are not signed in any way,
>    and enrolled by the user
>
> The latter are vouched for by the user by enrolling the certificate, and
> confirming that they really want to trust this certificate. Enrolling
> user certificates is vital for usability or secure boot. Adding extra
> step of creating a CA certificate stored on the same system only
> complicates things with no added benefit.

This all comes down to the generic fact that kernel should not
proactively define what it *expects* sysadmins.

CA based infrastructure like anything is a policy decision not
a decision to be enforced by kernel.

BR, Jarkko