Re: [RFC PATCH 12/12] IMA: Use the the system trusted keyrings instead of .ima_mok [ver #2]

[Mimi Zohar <zohar@linux.vnet.ibm.com>]

On Tue, 2016-03-08 at 16:14 +0200, Petko Manolov wrote:
> On 16-03-08 13:08:36, David Howells wrote:
> > Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
> > 
> > > Only certificates signed by a key on the system keyring were added to
> > > the IMA keyring, unless IMA_MOK_KEYRING was configured.  Then, the
> > > certificate could be signed by a either a key on the system or ima_mok
> > > keyrings.  To replicate this behavior, the default behavior should be to
> > > only permit certificates signed by a key on the builtin keyring, unless
> > > this new Kconfig is enabled.  Only then, permit certificates signed by a
> > > key on either the builtin or secondary keyrings to be added to the IMA
> > > keyring.
> > 
> > How about I change it to a choice-type item, with the following options:
> > 
> >  (1) No addition.
> > 
> >  (2) Addition restricted by built-in keyring.
> > 
> >  (3) Addition restricted by secondary keyring + built-in keyring.
> > 
> > where the second and third options then depend on the appropriate keyrings 
> > being enabled.
> 
> I would suggest leaving (1) and (3).  Since secondary keyring only accepts keys 
> signed by certificate in the system keyring I think (2) is redundant.  It adds 
> extra complexity (Kconfig is vague enough already) while it doesn't increase the 
> overall security by much.

I think you mean option 2 or 3, as option 1 implies not allowing any
keys to be added to the IMA keyring.

Mimi