Re: [PATCH v1 0/3] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys

On Thu, 1 Apr 2021 at 19:00, Ahmad Fatoum [off-list ref] wrote:

Hello Richard, Sumit,

On 01.04.21 15:17, Richard Weinberger wrote:

quoted

Sumit,

----- Ursprüngliche Mail -----

quoted

Von: "Sumit Garg" [off-list ref]
IIUC, this would require support for multiple trusted keys backends at
runtime but currently the trusted keys subsystem only supports a
single backend which is selected via kernel module parameter during
boot.

So the trusted keys framework needs to evolve to support multiple
trust sources at runtime but I would like to understand the use-cases
first. IMO, selecting the best trust source available on a platform
for trusted keys should be a one time operation, so why do we need to
have other backends available at runtime as well?

I thought about devices with a TPM-Chip and CAAM.

In this case why would one prefer to use CAAM when you have standards
compliant TPM-Chip which additionally offers sealing to specific PCR
(integrity measurement) values.

quoted

IMHO allowing only one backend at the same time is a little over simplified.

It is, but I'd rather leave this until it's actually needed.
What can be done now is adopting a format for the exported keys that would
make this extension seamless in future.

+1

-Sumit

Cheers,
Ahmad

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