Re: [PATCH] X.509: Partially revert patch to add validation against IMA MOK keyring

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

On Thu, 2016-01-07 at 00:34 +0000, David Howells wrote:
> David Howells <dhowells@redhat.com> wrote:
> 
> > Partially revert commit 41c89b64d7184a780f12f2cccdabe65cb2408893:
> > 
> > 	Author: Petko Manolov <petkan@mip-labs.com>
> > 	Date:   Wed Dec 2 17:47:55 2015 +0200
> > 	IMA: create machine owner and blacklist keyrings
> > 
> > The problem is that prep->trusted is a simple boolean and the additional
> > x509_validate_trust() call doesn't therefore distinguish levels of
> > trustedness, but is just OR'd with the result of validation against the
> > system trusted keyring.
> > 
> > However, setting the trusted flag means that this key may be added to *any*
> > trusted-only keyring - including the system trusted keyring.
> > 
> > Whilst I appreciate what the patch is trying to do, I don't think this is
> > quite the right solution.
> 
> Please apply this to security/next.

The only upstreamed trusted keyrings are the system keyring, which does
not permit user space to write to the keyring, and the 3 IMA keyrings.

For those systems without the Kconfig IMA_MOK_KEYRING option enabled,
get_ima_mok_keyring() does not change the existing behavior.  For
systems with IMA_MOK_KEYRING enabled, keys being added to the IMA
keyring, can be validated against the system keyring or the IMA MOK
keyring.

Mimi