Re: [RFC PATCH 12/12] IMA: Use the the system trusted keyrings instead of .ima_mok [ver #3]

From: Mimi Zohar
Date: Thu Mar 31 2016 - 08:22:49 EST


On Wed, 2016-03-30 at 17:19 +0100, David Howells wrote:
> Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> wrote:
>
> > > +choice
> > > + prompt "Allow keys to be added to the ima keyrings by userspace?"
> > > + depends on IMA_APPRAISE
> > > + depends on INTEGRITY_ASYMMETRIC_KEYS
> > > + default IMA_NO_ADD_TO_IMA_KEYRINGS
> >
> > In this patch, the choice should be between checking just the builtin
> > trusted keys or both the builtin trusted and secondary keys.
>
> The third option I've added is that you can't add to .ima at all. You only
> get what's included at build time. You don't want that option?

Adding keys directly to the IMA keyring is a new feature. There's
enough changes as it is, that this patch should be limited to
replicating existing usage, not adding new features.

> > if IMA is enabled, I'm not sure what IMA_NO_ADD_TO_IMA_KEYRINGS means.
>
> Oops. that should be IMA_KEYRINGS_COMPILE_LOAD_ONLY.

The default should be to validate keys against the builtin trusted keys,
like it is currently.

> "IMA_NO_ADD_TO_IMA_KEYRINGS" seemed to be phrased too clunkily, but the
> Kconfig parser warn you about the undefined symbol.
>
> > > +config IMA_KEYRINGS_COMPILE_LOAD_ONLY
> > > + bool "No runtime key addition"
> > ...
> > This could be useful for namespacing IMA.
>
> You said you didn't want this option above (to quote: In this patch, the
> choice should be between checking just the builtin trusted keys or both the
> builtin trusted and secondary keys.)

Does the ability of adding builtin X.509 certificates directly to the
IMA keyring already exist or is it something that still needs to be
done? Assuming the latter, this option would be added with the ability
of adding X.509 certificates directly to the IMA keyring.

Mimi