20240604 506 create loaded

[Firstyear]

Fixes #506

Start on created loaded.

Create loaded appears to work in the base case, but when using it for key derivation, it appears to be failing with:

[2024-06-05T04:39:58Z ERROR tss_esapi::context::tpm_commands::object_commands] Error in creating derived key: 0x000002D2
thread 'context_tests::tpm_commands::object_commands_tests::test_create_loaded::test_create_loaded_tpm_alg_kdf1_sp800_108' panicked at tss-esapi/tests/integration_tests/context_tests/tpm_commands/object_commands_tests.rs:519:14:
Failed to create derivation parent.: TssError(Tpm(FormatOne(TpmFormatOneResponseCode { error_number: Scheme, argument_number: Parameter(2) })))

I'm pretty sure I'm making a mistake in the derive_parent_public PublicBuilder parameters that I'm setting. Per the spec, this does need to be keyed hash, but I think given the parameters I've set, I think that we need to set the KDF1SP800_108 as the scheme when we create this key - currently though I think that's not possible as KeyHashSchemes are just for Xor and Hmac, not derivation.

So any advice would be more than welcome on how to proceed next :)

[Superhepper]

This is really not my area of expertise but it seems to me as it is not as simple as setting the object attributes of the key. The kind of object you create will depend on the object attributes of its parent not only the object attributes of the object it self.

Look at TCG TPM2, r1p59, Part3 Commands, Section 12.9.1

Hrmm but the error code suggests:

TPM_RC_SCHEME

inconsistent attributes decrypt, sign, restricted and key's scheme ID;
or hash algorithm is inconsistent with the scheme ID for keyed hash
object

[Firstyear]

Yes I did read that section. The problem I hit was that part 3 12.9.1 doesn't actually define a derivation parent - that's actually defined in part 1 4.19 as "loadable key used to derive other keys; a TPM_ALG_KEYEDHASH Parent Key" and part 1 25.1.5 table 24 states "Asymmetric keys and
symmetric keys with these attributes are Storage Parents, and hash objects with these attributes are
Derivation Parents. " where the attributes are sign=clear, decrypt=set, restricted=set.

I think the comment I wrote here needs to be updated to reflect this, but I still think the attributes I used on the key were correct :)