Add a script to increment kernel subkey and data key.

When we do perform firmware updates, we'd like to change the kernel subkey to ensure that new firmware and Chrome OS image stay in sync. This CL adds a scripts which makes it possible to do this revving in an automated manner.

The current versions rollback versions corresponding to the keyset are stored in key.versions. If we change the kernel subkey (to enforce firmware/Chrome OS lockstep), we must also update the firmware version. Similarly, since we modify the kernel subkey, we also generate a new set of kernel data keys. Thus, we also increment the kernel key version.

Change-Id: I364ab50bda115991dd4f69331d37291f66abbf36

BUG=chrome-os-partner:3274, chromium-os:8016
TEST=Manually tested using a newly generated keyset.

Review URL: http://codereview.chromium.org/6824059

scripts/keygeneration/common.sh

@@ -23,6 +23,27 @@ function alg_to_keylen {
   echo $(( 1 << (10 + ($1 / 3)) ))
 }
 
+# Default alrogithms.
+ROOT_KEY_ALGOID=11
+RECOVERY_KEY_ALGOID=11
+
+FIRMWARE_DATAKEY_ALGOID=7
+DEV_FIRMWARE_DATAKEY_ALGOID=7
+
+RECOVERY_KERNEL_ALGOID=11
+INSTALLER_KERNEL_ALGOID=11
+KERNEL_SUBKEY_ALGOID=7
+KERNEL_DATAKEY_ALGOID=4
+
+# Keyblock modes determine which boot modes a signing key is valid for use
+# in verification.
+FIRMWARE_KEYBLOCK_MODE=7
+DEV_FIRMWARE_KEYBLOCK_MODE=6  # Only allow in dev mode.
+RECOVERY_KERNEL_KEYBLOCK_MODE=11
+KERNEL_KEYBLOCK_MODE=7  # Only allow in non-recovery.
+INSTALLER_KERNEL_KEYBLOCK_MODE=10  # Only allow in Dev + Recovery.
+
+
 # Emit .vbpubk and .vbprivk using given basename and algorithm
 # NOTE: This function also appears in ../../utility/dev_make_keypair. Making
 # the two implementations the same would require some common.sh, which is more
@@ -32,9 +53,10 @@ function alg_to_keylen {
 function make_pair {
   local base=$1
   local alg=$2
+  local key_version=${3:-1}
   local len=$(alg_to_keylen $alg)
 
-  echo "creating $base keypair..."
+  echo "creating $base keypair (version = $key_version)..."
 
   # make the RSA keypair
   openssl genrsa -F4 -out "${base}_${len}.pem" $len
@@ -48,7 +70,7 @@ function make_pair {
   vbutil_key \
     --pack "${base}.vbpubk" \
     --key "${base}_${len}.keyb" \
-    --version 1 \
+    --version  "${key_version}" \
     --algorithm $alg
 
   # wrap the private key