Re: [TrouSerS-tech] [Ksummit-discuss] TPM MiniSummit @ LinuxCon Europe

From: Jarkko Sakkinen
Date: Tue Oct 07 2014 - 15:22:23 EST


On Tue, Oct 07, 2014 at 01:54:41PM -0400, Stefan Berger wrote:
> On 09/23/2014 12:42 PM, Andy Lutomirski wrote:
> >On Sep 22, 2014 2:07 AM, "Peter Huewe" <PeterHuewe@xxxxxx> wrote:
> >>Hi,
> >>
> >>I would like to 'invite' all interested parties in a short TPM minisummit where we can discuss the following hot topics of the TPM subsystem over a beer or two:
> >> - State of the TPM Subsystem
> >> - De-/Initialization Mess
> >> - Devm'ification
> >> - Testing
> >> - TPM 2.0 Support
> >> - Dependencies / interaction with other subsystems (e.g. keyring / IMA)
> >> - Status of old 1.1b TPM drivers, deprecation plans
> >> - ...
> >>
> >I am unlikely to be there, but I have a feature request / food for thought:
> >
> >Using a mandatory userspace daemon (e.g. trousers) for TPM access
> >sucks. Might it be possible to teach the kernel to handle context
> >save and restore and let multiple processes open the device at once?
> >Then a daemon wouldn't be necessary.
>
> Why add the complexity of swapping of authenticated sessions and keys into
> the kernel if you can handle this in userspace? You need a library that is
> aware of the number of key slots and slots for sessions in the TPM and swaps
> them in at out when applications need them. Trousers is such a library that
> was designed to cope with the limitations of the device and make its
> functionality available to all applications that want to access it.

One justification might be that kernel is also using TPM? TrouSerS can
not manage session for kernel internal use.

> Stefan

/Jarkko
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