Re: [RFC v2 0/6] Introduce TEE based Trusted Keys support

[Sumit Garg <sumit.garg@linaro.org>]

Hi Janne,

On Wed, 31 Jul 2019 at 12:41, Janne Karhunen <janne.karhunen@gmail.com> wrote:
>
> Hi,
>
> Interesting, I wrote something similar and posted it to the lists a while back:
> https://github.com/jkrh/linux/commit/d77ea03afedcb5fd42234cd834da8f8a0809f6a6
>
> Since there are no generic 'TEEs' available,

There is already a generic TEE interface driver available in kernel.
Have a look here: "Documentation/tee.txt".

> I implemented the same
> thing as a generic protocol translator. The shared memory binding for
> instance already assumes fair amount about the TEE and how that is
> physically present in the system. Besides, the help from usage of shm
> is pretty limited due to the size of the keydata.
>

If you look at patch #1 and #2, they add support to register kernel
memory buffer (keydata buffer in this case) with TEE to operate on. So
there isn't any limitation due to the size of the keydata.

-Sumit

>
> --
> Janne
>
>
>
>
> On Tue, Jul 30, 2019 at 3:26 PM Sumit Garg <sumit.garg@linaro.org> wrote:
> >
> > Add support for TEE based trusted keys where TEE provides the functionality
> > to seal and unseal trusted keys using hardware unique key. Also, this is
> > an alternative in case platform doesn't possess a TPM device.
> >
> > This series also adds some TEE features like:
> >
> > Patch #1, #2 enables support for registered kernel shared memory with TEE.
> >
> > Patch #3 enables support for private kernel login method required for
> > cases like trusted keys where we don't wan't user-space to directly access
> > TEE service to retrieve trusted key contents.
> >
> > Rest of the patches from #4 to #6 adds support for TEE based trusted keys.
> >
> > This patch-set has been tested with OP-TEE based pseudo TA which can be
> > found here [1].
> >
> > Also, this patch-set is dependent on generic Trusted Keys framework
> > patch-set [2].
> >
> > [1] https://github.com/OP-TEE/optee_os/pull/3082
> > [2] https://lkml.org/lkml/2019/7/18/284
> >
> > Changes in v2:
> > 1. Add reviewed-by tags for patch #1 and #2.
> > 2. Incorporate comments from Jens for patch #3.
> > 3. Switch to use generic trusted keys framework.
> >
> > Sumit Garg (6):
> >   tee: optee: allow kernel pages to register as shm
> >   tee: enable support to register kernel memory
> >   tee: add private login method for kernel clients
> >   KEYS: trusted: Introduce TEE based Trusted Keys
> >   doc: keys: Document usage of TEE based Trusted Keys
> >   MAINTAINERS: Add entry for TEE based Trusted Keys
> >
> >  Documentation/security/keys/index.rst       |   1 +
> >  Documentation/security/keys/tee-trusted.rst |  93 +++++++++
> >  MAINTAINERS                                 |   9 +
> >  drivers/tee/optee/call.c                    |   7 +
> >  drivers/tee/tee_core.c                      |   6 +
> >  drivers/tee/tee_shm.c                       |  16 +-
> >  include/keys/trusted-type.h                 |   3 +
> >  include/keys/trusted_tee.h                  |  66 +++++++
> >  include/linux/tee_drv.h                     |   1 +
> >  include/uapi/linux/tee.h                    |   8 +
> >  security/keys/Kconfig                       |   3 +
> >  security/keys/trusted-keys/Makefile         |   3 +-
> >  security/keys/trusted-keys/trusted-tee.c    | 282 ++++++++++++++++++++++++++++
> >  security/keys/trusted-keys/trusted.c        |   3 +
> >  14 files changed, 498 insertions(+), 3 deletions(-)
> >  create mode 100644 Documentation/security/keys/tee-trusted.rst
> >  create mode 100644 include/keys/trusted_tee.h
> >  create mode 100644 security/keys/trusted-keys/trusted-tee.c
> >
> > --
> > 2.7.4
> >