Merge pull request #2491 from flatcar/chewi/split-sbsign-job

Do Secure Boot signing for official builds in a separate additional job

Author: chewi

build_image

@@ -41,10 +41,10 @@ DEFINE_string disk_layout "" \
   "The disk layout type to use for this image."
 DEFINE_string group "${DEFAULT_GROUP}" \
   "The update group."
-DEFINE_boolean generate_update "${FLAGS_FALSE}" \
-  "Generate update payload. (prod only)"
 DEFINE_boolean extract_update "${FLAGS_TRUE}" \
-  "Extract the /usr partition for generating updates."
+  "Extract the /usr partition for generating updates. Only valid for the prod image."
+DEFINE_boolean generate_update "${FLAGS_TRUE}" \
+  "Generate update payload for testing. The update is signed with a dev key. The kernel is signed with a dev key (unofficial builds) or not at all (official builds). Only valid for the prod image. Implies --extract_update."
 DEFINE_string developer_data "" \
   "Insert a custom cloudinit file into the image."
 DEFINE_string devcontainer_binhost "${DEFAULT_DEVCONTAINER_BINHOST}" \
@@ -139,6 +139,11 @@ fi
 # Create the output directory and temporary mount points.
 mkdir -p "${BUILD_DIR}"
 
+# --generate_update implies --extract_update.
+if [[ ${FLAGS_generate_update} -eq ${FLAGS_TRUE} ]]; then
+  FLAGS_extract_update=${FLAGS_TRUE}
+fi
+
 DISK_LAYOUT="${FLAGS_disk_layout:-base}"
 CONTAINER_LAYOUT="${FLAGS_disk_layout:-container}"
 
@@ -169,11 +174,12 @@ fi
 if [[ "${PROD_IMAGE}" -eq 1 ]]; then
   IMAGE_BUILD_TYPE="prod"
   create_prod_image ${FLATCAR_PRODUCTION_IMAGE_NAME} ${DISK_LAYOUT} ${FLAGS_group} ${FLAGS_base_pkg} ${FLAGS_base_sysexts}
-  if [[ ${FLAGS_generate_update} -eq ${FLAGS_TRUE} ]]; then
-    generate_update "${FLATCAR_PRODUCTION_IMAGE_NAME}" ${DISK_LAYOUT}
-  elif [[ ${FLAGS_extract_update} -eq ${FLAGS_TRUE} ]]; then
+  if [[ ${FLAGS_extract_update} -eq ${FLAGS_TRUE} ]]; then
     extract_update "${FLATCAR_PRODUCTION_IMAGE_NAME}" "${DISK_LAYOUT}"
   fi
+  if [[ ${FLAGS_generate_update} -eq ${FLAGS_TRUE} ]]; then
+    generate_update "${FLATCAR_PRODUCTION_IMAGE_NAME}" "${DISK_LAYOUT}"
+  fi
   if [[ "${PROD_TAR}" -eq 1 ]]; then
     create_prod_tar ${FLATCAR_PRODUCTION_IMAGE_NAME}
   fi
@@ -182,9 +188,7 @@ if [[ "${SYSEXT}" -eq 1 ]]; then
   create_prod_sysexts "${FLATCAR_PRODUCTION_IMAGE_NAME}"
 fi
 
-if [[ ${FLAGS_generate_update} -eq ${FLAGS_TRUE} ]] || \
-   [[ ${FLAGS_extract_update} -eq ${FLAGS_TRUE} ]]
-then
+if [[ ${FLAGS_extract_update} -eq ${FLAGS_TRUE} ]]; then
   zip_update_tools
 fi
 

build_library/build_image_util.sh

@@ -61,57 +61,43 @@ delete_prompt() {
 extract_update() {
   local image_name="$1"
   local disk_layout="$2"
-  local update_path="${BUILD_DIR}/${image_name%_image.bin}_update.bin"
+  local update="${BUILD_DIR}/${image_name%_image.bin}_update.bin"
 
   "${BUILD_LIBRARY_DIR}/disk_util" --disk_layout="${disk_layout}" \
-    extract "${BUILD_DIR}/${image_name}" "USR-A" "${update_path}"
+    extract "${BUILD_DIR}/${image_name}" "USR-A" "${update}"
 
   # Compress image
-  files_to_evaluate+=( "${update_path}" )
+  files_to_evaluate+=( "${update}" )
   compress_disk_images files_to_evaluate
-
-  # For production as well as dev builds we generate a dev-key-signed update
-  # payload for running tests (the signature won't be accepted by production systems).
-  local update_test="${BUILD_DIR}/flatcar_test_update.gz"
-  delta_generator \
-      -private_key "/usr/share/update_engine/update-payload-key.key.pem" \
-      -new_image "${update_path}" \
-      -new_kernel "${BUILD_DIR}/${image_name%.bin}.vmlinuz" \
-      -out_file "${update_test}"
-}
-
-zip_update_tools() {
-  # There isn't a 'dev' variant of this zip, so always call it production.
-  local update_zip="flatcar_production_update.zip"
-
-  info "Generating update tools zip"
-  # Make sure some vars this script needs are exported
-  export REPO_MANIFESTS_DIR SCRIPTS_DIR
-  "${BUILD_LIBRARY_DIR}/generate_au_zip.py" \
-    --arch "$(get_sdk_arch)" --output-dir "${BUILD_DIR}" --zip-name "${update_zip}"
 }
 
 generate_update() {
   local image_name="$1"
   local disk_layout="$2"
   local image_kernel="${BUILD_DIR}/${image_name%.bin}.vmlinuz"
-  local update_prefix="${image_name%_image.bin}_update"
-  local update="${BUILD_DIR}/${update_prefix}"
+  local update="${BUILD_DIR}/${image_name%_image.bin}_update.bin"
   local devkey="/usr/share/update_engine/update-payload-key.key.pem"
 
+  # Extract the partition if it isn't extracted already.
+  [[ -s ${update} ]] || extract_update "${image_name}" "${disk_layout}"
+
   echo "Generating update payload, signed with a dev key"
-  "${BUILD_LIBRARY_DIR}/disk_util" --disk_layout="${disk_layout}" \
-    extract "${BUILD_DIR}/${image_name}" "USR-A" "${update}.bin"
   delta_generator \
       -private_key "${devkey}" \
-      -new_image "${update}.bin" \
+      -new_image "${update}" \
       -new_kernel "${image_kernel}" \
-      -out_file "${update}.gz"
+      -out_file "${BUILD_DIR}/flatcar_test_update.gz"
+}
 
-  # Compress image
-  declare -a files_to_evaluate
-  files_to_evaluate+=( "${update}.bin" )
-  compress_disk_images files_to_evaluate
+zip_update_tools() {
+  # There isn't a 'dev' variant of this zip, so always call it production.
+  local update_zip="flatcar_production_update.zip"
+
+  info "Generating update tools zip"
+  # Make sure some vars this script needs are exported
+  local -x REPO_MANIFESTS_DIR SCRIPTS_DIR
+  "${BUILD_LIBRARY_DIR}/generate_au_zip.py" \
+    --arch "$(get_sdk_arch)" --output-dir "${BUILD_DIR}" --zip-name "${update_zip}"
 }
 
 # ldconfig cannot generate caches for non-native arches.
@@ -805,10 +791,12 @@ EOF
         seek=${verity_offset} count=64 bs=1 status=none
   fi
 
-  # Sign the kernel after /usr is in a consistent state and verity is calculated
-  [[ ${COREOS_OFFICIAL:-0} -ne 1 ]] && \
-  do_sbsign --output "${root_fs_dir}/boot/flatcar/vmlinuz-a"{,}
-  cleanup_sbsign_certs
+  # Sign the kernel after /usr is in a consistent state and verity is
+  # calculated. Only for unofficial builds as official builds get signed later.
+  if [[ ${COREOS_OFFICIAL:-0} -ne 1 ]]; then
+    do_sbsign --output "${root_fs_dir}/boot/flatcar/vmlinuz-a"{,}
+    cleanup_sbsign_certs
+  fi
 
   if [[ -n "${image_kernel}" ]]; then
     # copying kernel from vfat so ignore the permissions
@@ -894,3 +882,67 @@ EOF
   cleanup_mounts "${root_fs_dir}"
   trap - EXIT
 }
+
+sbsign_image() {
+  local image_name="$1"
+  local disk_layout="$2"
+  local root_fs_dir="$3"
+  local image_kernel="$4"
+  local pcr_policy="$5"
+  local image_grub="$6"
+
+  local disk_img="${BUILD_DIR}/${image_name}"
+  local EFI_ARCH
+
+  case "${BOARD}" in
+    amd64-usr) EFI_ARCH="x64" ;;
+    arm64-usr) EFI_ARCH="aa64" ;;
+    *) die "Unknown board ${BOARD@Q}" ;;
+  esac
+
+  "${BUILD_LIBRARY_DIR}/disk_util" --disk_layout="${disk_layout}" \
+      mount "${disk_img}" "${root_fs_dir}"
+  trap "cleanup_mounts '${root_fs_dir}'; cleanup_sbsign_certs" EXIT
+
+  # Sign the kernel with the shim-embedded key.
+  do_sbsign --output "${root_fs_dir}/boot/flatcar/vmlinuz-a"{,}
+
+  if [[ -n "${image_kernel}" ]]; then
+    # copying kernel from vfat so ignore the permissions
+    cp --no-preserve=mode \
+        "${root_fs_dir}/boot/flatcar/vmlinuz-a" \
+        "${BUILD_DIR}/${image_kernel}"
+  fi
+
+  # Sign GRUB and mokmanager(mm) with the shim-embedded key.
+  do_sbsign --output "${root_fs_dir}/boot/EFI/boot/grub${EFI_ARCH}.efi"{,}
+  do_sbsign --output "${root_fs_dir}/boot/EFI/boot/mm${EFI_ARCH}.efi"{,}
+
+  # copying from vfat so ignore permissions
+  if [[ -n "${image_grub}" ]]; then
+    cp --no-preserve=mode "${root_fs_dir}/boot/EFI/boot/grub${EFI_ARCH}.efi" \
+        "${BUILD_DIR}/${image_grub}"
+  fi
+
+  if [[ -n "${pcr_policy}" ]]; then
+    mkdir -p "${BUILD_DIR}/pcrs"
+    "${BUILD_LIBRARY_DIR}"/generate_kernel_hash.py \
+        "${root_fs_dir}/boot/flatcar/vmlinuz-a" "${FLATCAR_VERSION}" \
+        >"${BUILD_DIR}/pcrs/kernel.config"
+  fi
+
+  cleanup_mounts "${root_fs_dir}"
+  cleanup_sbsign_certs
+  trap - EXIT
+
+  if [[ -n "${pcr_policy}" ]]; then
+    "${BUILD_LIBRARY_DIR}"/generate_grub_hashes.py \
+        "${disk_img}" /usr/lib/grub/ "${BUILD_DIR}/pcrs" "${FLATCAR_VERSION}"
+
+    info "Generating $pcr_policy"
+    pushd "${BUILD_DIR}" >/dev/null
+    zip --quiet -r -9 "${BUILD_DIR}/${pcr_policy}" pcrs
+    popd >/dev/null
+    rm -rf "${BUILD_DIR}/pcrs"
+  fi
+}

build_library/grub_install.sh

@@ -205,7 +205,7 @@ case "${FLAGS_target}" in
                 --output "${ESP_DIR}/EFI/boot/boot${EFI_ARCH}.efi" \
                 "${BOARD_ROOT}/usr/lib/shim/shim${EFI_ARCH}.efi"
         else
-            # Official build: Copy the unsigned files.
+            # Official build: Copy signed shim and mm for signing later.
             sudo cp "${BOARD_ROOT}/usr/lib/shim/mm${EFI_ARCH}.efi" \
                 "${ESP_DIR}/EFI/boot/mm${EFI_ARCH}.efi"
             sudo cp "${BOARD_ROOT}/usr/lib/shim/shim${EFI_ARCH}.efi" \

build_library/modify_image_util.sh

@@ -180,6 +180,15 @@ EOF
       "${image_initrd_contents_wtd}" \
       "${image_disk_usage}"
 
+  # Official builds will sign and upload these files later, so remove them to
+  # prevent them from being uploaded now.
+  if [[ ${COREOS_OFFICIAL:-0} -eq 1 ]]; then
+    rm -v \
+        "${BUILD_DIR}/${image_kernel}" \
+        "${BUILD_DIR}/${image_pcr_policy}" \
+        "${BUILD_DIR}/${image_grub}"
+  fi
+
   local files_to_evaluate=( "${BUILD_DIR}/${image_name}" )
   compress_disk_images files_to_evaluate
 }
@@ -225,3 +234,26 @@ create_prod_sysexts() {
       -out_file "${BUILD_DIR}/flatcar_test_update-${name}.gz"
   done
 }
+
+sbsign_prod_image() {
+  local image_name="$1"
+  local disk_layout="$2"
+
+  info "Signing production image ${image_name} for Secure Boot"
+  local root_fs_dir="${BUILD_DIR}/rootfs"
+  local image_prefix="${image_name%.bin}"
+  local image_kernel="${image_prefix}.vmlinuz"
+  local image_pcr_policy="${image_prefix}_pcr_policy.zip"
+  local image_grub="${image_prefix}.grub"
+
+  sbsign_image \
+      "${image_name}" \
+      "${disk_layout}" \
+      "${root_fs_dir}" \
+      "${image_kernel}" \
+      "${image_pcr_policy}" \
+      "${image_grub}"
+
+  local files_to_evaluate=( "${BUILD_DIR}/${image_name}" )
+  compress_disk_images files_to_evaluate
+}