T861: sign all Kernel modules with an ephemeral key

The shim review board (which is the secure boot base loader) recommends using
ephemeral keys when signing the Linux Kernel. This commit enables the Kernel
build system to generate a one-time ephemeral key that is used to:

* sign all build-in Kernel modules
* sign all other out-of-tree Kernel modules

The key lives in /tmp and is destroyed after the build container exits and is
named: "VyOS build time autogenerated kernel key".

In addition the Kernel now uses CONFIG_MODULE_SIG_FORCE. This now makes it
unable to load any Kernel Module to the image that is NOT signed by the
ephemeral key.

1 files changed, 7 insertions, 0 deletions

diff --git a/scripts/package-build/linux-kernel/build.py b/scripts/package-build/linux-kernel/build.py
index 1bcab686..3aacc7f1 100755
--- a/scripts/package-build/linux-kernel/build.py
+++ b/scripts/package-build/linux-kernel/build.py
@@ -98,6 +98,8 @@ def build_package(package: dict, dependencies: list) -> None:
             build_intel_ixgbe()
         elif package['build_cmd'] == 'build_intel_ixgbevf':
             build_intel_ixgbevf()
+        elif package['build_cmd'] == 'build_mellanox_ofed':
+            build_mellanox_ofed()
         elif package['build_cmd'] == 'build_jool':
             build_jool()
         elif package['build_cmd'] == 'build_openvpn_dco':
@@ -183,6 +185,11 @@ def build_intel_ixgbevf():
     run(['./build-intel-ixgbevf.sh'], check=True)
 
 
+def build_mellanox_ofed():
+    """Build Mellanox OFED"""
+    run(['sudo ./build-mellanox-ofed.sh'], check=True)
+
+
 def build_jool():
     """Build Jool"""
     run(['echo y | ./build-jool.py'], check=True, shell=True)