PCI/CMA: Expose certificates in sysfs
The kernel already caches certificate chains retrieved from a device
upon authentication. Expose them in "slot[0-7]" files in sysfs for
examination by user space.
As noted in the ABI documentation, the "slot[0-7]" files always have a
file size of 65535 bytes (the maximum size of a certificate chain per
SPDM 1.0.0 table 18), even if the certificate chain in the slot is
actually smaller. Although it would be possible to use the certifiate
chain's actual size as the file size, doing so would require a separate
struct attribute_group for each device, which would occupy additional
memory.
Slots are visible in sysfs even if they're currently unprovisioned
because a future commit will add support for certificate provisioning
by writing to the "slot[0-7]" files.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
6 files changed
