Re: One question about trusted key of keyring in Linux kernel.

[Jarkko Sakkinen]

On Wed, Dec 11, 2019 at 07:23:59PM +0200, Jarkko Sakkinen wrote:
> On Mon, Dec 09, 2019 at 12:31:53PM -0800, James Bottomley wrote:
> > On Mon, 2019-12-09 at 21:47 +0200, Jarkko Sakkinen wrote:
> > > On Mon, Dec 02, 2019 at 10:55:32AM -0800, James Bottomley wrote:
> > > > blob but it looks like we need to fix the API.  I suppose the good
> > > > news is given this failure that we have the opportunity to rewrite
> > > > the API since no-one else can have used it for anything because of
> > > > this.  The
> > > 
> > > I did successfully run this test when I wrote it 5 years ago:
> > > 
> > > https://github.com/jsakkine-intel/tpm2-scripts/blob/master/keyctl-smo
> > > ke.sh
> > > 
> > > Given that there is API a way must be found that backwards
> > > compatibility
> > > is not broken. New format is fine but it must co-exist.
> > 
> > The old API is unsupportable in the combination of policy + auth as I
> > already explained.  The kernel doesn't have access to the nonces to
> > generate the HMAC because the session was created by the user and the
> > API has no way to pass them in (plus passing them in would be a huge
> > security failure if we tried).  Given that Shirley appears to be the
> > first person ever to try this, I don't think the old API has grown any
> > policy users so its safe to remove it.  If we get a complaint, we can
> > discuss adding it back.
> 
> It works within limits so it can be definitely be maintained for
> backwards compatibility.
> 
> Also, you are making a claim of the users that we cannot verify.
> 
> Finally, the new feature neither handles sessions. You claim that
> it could be added later. I have to deny that because until session
> handling is there we have no ways to be sure about that.
> 
> I see your point but this needs more consideration. It does not
> make sense to rush.

Also can test the current patch set as soon as I've done with
release critical tpm_tis bug even if I don't agree on every
point.

/Jarkko