Hello Richard,

On 31.03.21 21:36, Richard Weinberger wrote:

James,

----- Ursprüngliche Mail -----

quoted

Von: "James Bottomley" [off-list ref]
Well, yes.  For the TPM, there's a defined ASN.1 format for the keys:

https://git.kernel.org/pub/scm/linux/kernel/git/jejb/openssl_tpm2_engine.git/tree/tpm2-asn.h

and part of the design of the file is that it's distinguishable either
in DER or PEM (by the guards) format so any crypto application can know
it's dealing with a TPM key simply by inspecting the file.  I think you
need the same thing for CAAM and any other format.

We're encouraging new ASN.1 formats to be of the form

SEQUENCE {
   type   OBJECT IDENTIFIER
   ... key specific fields ...
}

Where you choose a defined OID to represent the key and that means
every key even in DER form begins with a unique binary signature.

I like this idea.
Ahmad, what do you think?

That way we could also get rid off the kernel parameter and all the fall back logic,
given that we find a way to reliable detect TEE blobs too...

Sounds good to me. Sumit, your thoughts on doing this for TEE as well?

Thanks,
//richard

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