Re: [tpmdd-devel] [PATCH RFC 0/4] RFC: in-kernel resource manager

[Jason Gunthorpe <jgunthorpe@obsidianresearch.com>]

On Tue, Jan 03, 2017 at 04:29:59PM -0800, James Bottomley wrote:
> On Tue, 2017-01-03 at 17:17 -0700, Jason Gunthorpe wrote:
> > On Tue, Jan 03, 2017 at 02:39:58PM -0800, James Bottomley wrote:
> > 
> > > > I think we should also consider TPM 1.2 support in all of this, 
> > > > it is still a very popular peice of hardware and it is equally 
> > > > able to support a RM.
> > > 
> > > I've been running with the openssl and gnome-keyring patches in 1.2 
> > > for months now.  The thing about 1.2 is that the volatile store is 
> > > much larger, so there's a lot less of a need for a RM.  It's only a
> > > requirement in 2.0 because most shipping TPMs only seem to have 
> > > room for about 3 objects.
> > 
> > It would be great if the 1.2 RM could support just enough to allow 
> > RSA key operations from userspace, without key virtualization. That 
> > would allow the plugins that already exist to move to the RM 
> > interface and we can get rid of the hard dependency on trousers.
> [getting long, let's divide into separate issues]
> 
> They actually already do: Trousers, for all its annoying complexity,
> doesn't actually implement a resource manager, so we should be able to
> do all the RSA operations we want today with the current 1.2 interface
> and no RM.

The current interface cannot be used by unprivileged users. I want to
see the kernel provide an unprivileged safe interface for both TPM 1.2
and TPM 2.0

> The difficulty is no API ... unless you want to speak at
> the TPM command level and do all the HMAC calculations yourself.

I think the openssl RSA method could certainly do the TPM command
level with not really a big problem.

That would avoid all these crazy dependencies and debate :|

I have a very good idea what that would look like for tpm 1.2 and I
would estimate < 500 lines....

Jason