+ Thirupathaiah (TEE fTPM driver author) On Wed, 10 May 2023 at 20:28, Etienne Carriere <etienne.carriere@xxxxxxxxxx> wrote: > > Hello Sumit, > > On Wed, 10 May 2023 at 12:24, Sumit Garg <sumit.garg@xxxxxxxxxx> wrote: > > > > Hi Etienne, > > > > On Sat, 6 May 2023 at 00:14, Etienne Carriere > > <etienne.carriere@xxxxxxxxxx> wrote: > > > > > > Changes fTPM TEE driver to open the TEE session with REE kernel login > > > identifier rather than public login. This is needed in case fTPM service > > > it denied to user land application and restricted to kernel operating > > > system services only. > > > > This is a valid restriction to avoid any unintended use of fTPM by > > user-space. But has the corresponding patch landed in fTPM TA which > > would enforce this restriction? > > Not yet. Actually, I've posted some other change requests in the repo > [1] but got no feedback. Not nice from me but I didn't post any other > changes since. Hi Thirupathaiah, Is there any plan to maintain fTPM OP-TEE TA going forward? As otherwise users have to maintain downstream patches or forks. > In the mean time, I think Linux kernel should be ready for this before > fTPM implementation is fixed. > Note that U-Boot already integrate this login identifier change, see [2]. Yeah you are right but without a corresponding reference fTPM TA, it won't be possible to test this capability. -Sumit > > [1] https://github.com/microsoft/ms-tpm-20-ref/pull/83 > [2] https://source.denx.de/u-boot/u-boot/-/commit/33ba80303e93869c439828dd289fb8ef64ed3bfc > > Best regards, > Etienne > > > > > -Sumit > > > > > > > > Signed-off-by: Etienne Carriere <etienne.carriere@xxxxxxxxxx> > > > --- > > > drivers/char/tpm/tpm_ftpm_tee.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c > > > index 528f35b14fb6..6d32e260af43 100644 > > > --- a/drivers/char/tpm/tpm_ftpm_tee.c > > > +++ b/drivers/char/tpm/tpm_ftpm_tee.c > > > @@ -241,7 +241,7 @@ static int ftpm_tee_probe(struct device *dev) > > > /* Open a session with fTPM TA */ > > > memset(&sess_arg, 0, sizeof(sess_arg)); > > > export_uuid(sess_arg.uuid, &ftpm_ta_uuid); > > > - sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC; > > > + sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL; > > > sess_arg.num_params = 0; > > > > > > rc = tee_client_open_session(pvt_data->ctx, &sess_arg, NULL); > > > -- > > > 2.25.1 > > >
