Re: [PATCH v6 4/6] security: keys: trusted: use ASN.1 TPM2 key format for the blobs

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Tue, Mar 03, 2020 at 03:42:21PM -0500, James Bottomley wrote:
> On Tue, 2020-03-03 at 22:06 +0200, Jarkko Sakkinen wrote:
> > On Mon, Mar 02, 2020 at 07:27:57AM -0500, James Bottomley wrote:
> > > Modify the TPM2 key format blob output to export and import in the
> > > ASN.1 form for TPM2 sealed object keys.  For compatibility with
> > > prior
> > > trusted keys, the importer will also accept two TPM2B quantities
> > > representing the public and private parts of the key.  However, the
> > > export via keyctl pipe will only output the ASN.1 format.
> > > 
> > > The benefit of the ASN.1 format is that it's a standard and thus
> > > the
> > > exported key can be used by userspace tools (openssl_tpm2_engine,
> > > openconnect and tpm2-tss-engine).  The format includes policy
> > > specifications, thus it gets us out of having to construct policy
> > > handles in userspace and the format includes the parent meaning you
> > > don't have to keep passing it in each time.
> > > 
> > > This patch only implements basic handling for the ASN.1 format, so
> > > keys with passwords but no policy.
> > > 
> > > Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.c
> > > om>
> > 
> > tpm_key (like you have tpm2_key prefix).
> 
> OK, I should probably do tpm2_key as the prefix since TPM 1.2 cannot do
>  policy, that's a TPM 2 only thing.

Agreed that would be even better.

/Jarkko