Start creating base images

files/scripts/sign-check.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+
+# Copyright 2025 Universal Blue
+# Copyright 2025 The Secureblue Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software distributed under the License is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and limitations under the License.
+
+set -oue pipefail
+
+KERNEL="$1"
+module="$2"
+PUBLIC_CERT="$3"
+
+kmod_sig="/tmp/kmod.sig"
+kmod_p7s="/tmp/kmod.p7s"
+kmod_data="/tmp/kmod.data"
+/usr/src/kernels/"${KERNEL}"/scripts/extract-module-sig.pl -s "${module}" > "${kmod_sig}"
+openssl pkcs7 -inform der -in "${kmod_sig}" -out "${kmod_p7s}"
+/usr/src/kernels/"${KERNEL}"/scripts/extract-module-sig.pl -0 "${module}" > "${kmod_data}"
+if openssl cms -verify -binary -inform PEM \
+    -in "${kmod_p7s}" \
+    -content "${kmod_data}" \
+    -certfile "${PUBLIC_CERT}" \
+    -out "/dev/null" \
+    -nointern -noverify
+  then
+  echo "Signature Verified for ${module}"
+else
+  echo "Signature Failed for ${module}"
+  exit 1
+fi