Extract public key ID from cert

Extracts keyid inline using openssl commands.
The keyid is passed as one of the kernel command line parameters
for the dm-android-verity module to mount root fs(system)
with verity enabled.

(cherry-picked from 3af315aed5d657942b28ccae342324b9ee90116d
https://googleplex-android-review.git.corp.google.com/#/c/1061691/)

BUG: 28384658
Change-Id: I8efbe1b0e415ef1d396f9b51cfa4b3fa01b22484
diff --git a/core/Makefile b/core/Makefile
index 02bd4f7..79faae1 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -533,12 +533,6 @@
 
 INTERNAL_BOOTIMAGE_FILES := $(filter-out --%,$(INTERNAL_BOOTIMAGE_ARGS))
 
-BOARD_KERNEL_CMDLINE := $(strip $(BOARD_KERNEL_CMDLINE))
-ifdef BOARD_KERNEL_CMDLINE
-  INTERNAL_BOOTIMAGE_ARGS += --cmdline "$(BOARD_KERNEL_CMDLINE)"
-  INTERNAL_BVBTOOL_MAKE_BOOT_IMAGE_ARGS += --kernel_cmdline "$(BOARD_KERNEL_CMDLINE)"
-endif
-
 BOARD_KERNEL_BASE := $(strip $(BOARD_KERNEL_BASE))
 ifdef BOARD_KERNEL_BASE
   INTERNAL_BOOTIMAGE_ARGS += --base $(BOARD_KERNEL_BASE)
@@ -549,6 +543,18 @@
   INTERNAL_BOOTIMAGE_ARGS += --pagesize $(BOARD_KERNEL_PAGESIZE)
 endif
 
+ifeq ($(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY),true)
+ifeq ($(BOARD_BUILD_SYSTEM_ROOT_IMAGE),true)
+VERITY_KEYID := veritykeyid=id:`openssl x509 -in $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VERITY_SIGNING_KEY).x509.pem -text \
+                | grep keyid | sed 's/://g' | tr -d '[:space:]' | tr '[:upper:]' '[:lower:]' | sed 's/keyid//g'`
+endif
+endif
+
+BOARD_KERNEL_CMDLINE := $(strip $(BOARD_KERNEL_CMDLINE) $(VERITY_KEYID))
+ifdef BOARD_KERNEL_CMDLINE
+INTERNAL_BOOTIMAGE_ARGS += --cmdline "$(BOARD_KERNEL_CMDLINE)"
+endif
+
 INTERNAL_MKBOOTIMG_VERSION_ARGS := \
     --os_version $(PLATFORM_VERSION) \
     --os_patch_level $(PLATFORM_SECURITY_PATCH)