On Sun, 9 Dec 2018, Nayna Jain wrote: > On secure boot enabled systems, a verified kernel may need to kexec > additional kernels. For example, it may be used as a bootloader needing > to kexec a target kernel or it may need to kexec a crashdump kernel. In > such cases, it may want to verify the signature of the next kernel > image. > > It is further possible that the kernel image is signed with third party > keys which are stored as platform or firmware keys in the 'db' variable. > The kernel, however, can not directly verify these platform keys, and an > administrator may therefore not want to trust them for arbitrary usage. > In order to differentiate platform keys from other keys and provide the > necessary separation of trust, the kernel needs an additional keyring to > store platform keys. > > This patch creates the new keyring called ".platform" to isolate keys > provided by platform from keys by kernel. These keys are used to > facilitate signature verification during kexec. Since the scope of this > keyring is only the platform/firmware keys, it cannot be updated from > userspace. > > This keyring can be enabled by setting CONFIG_INTEGRITY_PLATFORM_KEYRING. > > Signed-off-by: Nayna Jain <nayna@xxxxxxxxxxxxx> > Reviewed-by: Mimi Zohar <zohar@xxxxxxxxxxxxx> > Acked-by: Serge Hallyn <serge@xxxxxxxxxx> Reviewed-by: James Morris <james.morris@xxxxxxxxxxxxx> -- James Morris <jmorris@xxxxxxxxx>
