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

From: Petko Manolov
Date: Tue Mar 08 2016 - 09:14:41 EST

On 16-03-08 13:08:36, David Howells wrote:
> Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> 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.