Re: [PATCH v8 4/5] IMA: Add support to limit measuring keys

From: Mimi Zohar <zohar@linux.ibm.com>
To: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
	linux-integrity@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, keyrings@vger.kernel.org
Subject: Re: [PATCH v8 4/5] IMA: Add support to limit measuring keys
Date: Thu, 21 Nov 2019 00:53:31 +0000	[thread overview]
Message-ID: <1574297611.4793.154.camel@linux.ibm.com> (raw)
In-Reply-To: <fef8fc67-643d-e579-9628-6516fd02b4db@linux.microsoft.com>

On Wed, 2019-11-20 at 16:03 -0800, Lakshmi Ramasubramanian wrote:
> On 11/20/2019 3:19 PM, Mimi Zohar wrote:
> 
> Hi Mimi,
> 
> >> The above can be used to correlate the key measurement IMA entry,
> >> ima-sig and ima-modsig entries using the same key.
> > 
> > True, but associating the public key measurement with the file
> > signature requires information from the certificate (e.g. issuer,
> > serial number, and/or subject, subject keyid).
> > 
> > For a regression test, it would be nice if the key measurement,
> > itself, contained everything needed in order to validate the file
> > signatures in the measurement list.
> 
> I am just trying to understand your asks - Please clarify:
> 
> 1, My change includes only the public key and not the entire certificate 
> information in the measured buffer.
> 
> Should I update this current patch set to measure the entire cert. Or, 
> can that be done as a separate patch set?
> 
> 2, Should a regression test be part of this patch set for the key 
> measurement changes to be accepted?

Once the key measurement is defined and upstreamed, changing it would
result in a regression. ┬áIf we think that it would change multiple
times, then perhaps the buffer measurement needs to contain some sort
of versioning.

I would very much like for a regression test to be included in this
patch set, but it isn't a requirement, as long as everything needed
for verifying a signature is included in the key measurement.

Mimi