On Wed, 21 Apr 2021 at 22:51, James Bottomley [off-list ref] wrote:

On Wed, 2021-04-21 at 16:38 +0530, Sumit Garg wrote:

quoted

Hi James,

On Wed, 21 Apr 2021 at 04:47, James Bottomley [off-list ref]
wrote:

quoted

On Mon, 2021-03-01 at 18:41 +0530, Sumit Garg wrote:

quoted

Current trusted keys framework is tightly coupled to use TPM
device as an underlying implementation which makes it difficult
for implementations like Trusted Execution Environment (TEE) etc.
to provide trusted keys support in case platform doesn't posses a
TPM device.

Add a generic trusted keys framework where underlying
implementations can be easily plugged in. Create struct
trusted_key_ops to achieve this, which contains necessary
functions of a backend.

Also, define a module parameter in order to select a particular
trust source in case a platform support multiple trust sources.
In case its not specified then implementation itetrates through
trust sources list starting with TPM and assign the first trust
source as a backend which has initiazed successfully during
iteration.

Note that current implementation only supports a single trust
source at runtime which is either selectable at compile time or
during boot via aforementioned module parameter.

You never actually tested this, did you?  I'm now getting EINVAL
from all the trusted TPM key operations because of this patch.

Unfortunately, I don't possess a development machine with a TPM
device. So mine testing was entirely based on TEE as a backend which
doesn't support any optional parameters. And that being the reason I
didn't catch this issue at first instance.

Is there any TPM emulation environment available that I can use for
testing?

Well use the same as we all use: A software TPM running in the host
coupled with a virtual machine guest for the kernel:

https://en.opensuse.org/Software_TPM_Emulator_For_QEMU

It doesn't catch interface issues (like TIS timeouts) but it does catch
TPM operations problems like this patch had.

Thanks for the pointer. I will use it for future testing.

-Sumit

James