Add an ioctl that lets an application retrieve which keys are in use by the
TPM, i.e., file encryption or migration key
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
The migration key ensures that TPM state blobs, when retrieved using the
ioctl for getting state blobs, are always encrypted with this key.
When the state is later on loaded back into the TPM using the ioctl
to set the state blobs, the migration key is used to decrypt them.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>