Re: [PATCH] KEYS: trusted: Re-orchestrate tpm2_read_public() calls

Jarkko Sakkinen
2025-12-04T23:20:30Z

On Fri, Dec 05, 2025 at 12:31:27AM +0200, Jarkko Sakkinen wrote:
> tpm2_load_cmd() and tpm2_unseal_cmd() use the same parent, and calls to
> tpm_buf_append_name() cause the exact same TPM2_ReadPublic command to be
> sent to the chip, causing unnecessary traffic.
>
> 1. Export tpm2_read_public in order to make it callable from 'trusted_tpm2'.
> 2. Re-orchestrate tpm2_seal_trusted() and tpm2_unseal_trusted() in order to
> halve the name resolutions required:
> 2a. Move tpm2_read_public() calls into trusted_tpm2.
> 2b. Pass TPM name to tpm_buf_append_name().
> 2c. Rework tpm_buf_append_name() to use the pre-resolved name.
>
> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

If ASN.1 blob would contain also name of the parent then zero
tpm2_read_public() calls would be required i.e., the main bottleneck
here inherits from the limitations of the file format itself.

BR, Jarkko