evm: load x509 certificate from the kernel

This patch defines configuration option and the evm_load_x509() hook
to load X509 certificate into the EVM trusted kernel keyring.

Changes in v4:
* Patch description updated

Changes in v3:
* Removed EVM_X509_PATH definition. CONFIG_EVM_X509_PATH is used
  directly.

Changes in v2:
* default key patch changed to /etc/keys

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
4 files changed