Hi Nayna, On Sun, 2018-11-25 at 20:44 +0530, 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 possible that the new 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/firmware keys. > > The secure boot key database is expected to store the keys as EFI > Signature List(ESL). The patch set uses David Howells and Josh Boyer's > patch to access and parse the ESL to extract the certificates and load > them onto the platform keyring. > > The last patch in this patch set adds support for IMA-appraisal to > verify the kexec'ed kernel image based on keys stored in the platform > keyring. > > Changelog: > > v0: > - The original patches loaded the certificates onto the secondary > trusted keyring. This patch set defines a new keyring named > ".platform" and adds the certificates to this new keyring > - removed CONFIG EFI_SIGNATURE_LIST_PARSER and LOAD_UEFI_KEYS > - moved files from certs/ to security/integrity/platform_certs/ This patch set is looking really good! There are a couple of checkpatch.pl warnings that need to be addressed before these patches can be upstreamed. I'd also like to see some Reviews/Acks for them as well. For the time being these patches are queued in the #next-integrity- queued branch. https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity. git/ thanks! Mimi > > Dave Howells (2): > efi: Add EFI signature data types > efi: Add an EFI signature blob parser > > Josh Boyer (2): > efi: Import certificates from UEFI Secure Boot > efi: Allow the "db" UEFI variable to be suppressed > > Nayna Jain (3): > integrity: define a trusted platform keyring > integrity: load certs to the platform keyring > ima: support platform keyring for kernel appraisal > > include/linux/efi.h | 34 ++++ > security/integrity/Kconfig | 11 ++ > security/integrity/Makefile | 5 + > security/integrity/digsig.c | 115 ++++++++---- > security/integrity/ima/ima_appraise.c | 11 +- > security/integrity/integrity.h | 23 ++- > security/integrity/platform_certs/efi_parser.c | 112 ++++++++++++ > security/integrity/platform_certs/load_uefi.c | 192 +++++++++++++++++++++ > .../integrity/platform_certs/platform_keyring.c | 62 +++++++ > 9 files changed, 527 insertions(+), 38 deletions(-) > create mode 100644 security/integrity/platform_certs/efi_parser.c > create mode 100644 security/integrity/platform_certs/load_uefi.c > create mode 100644 security/integrity/platform_certs/platform_keyring.c >
