diff --git a/core/Makefile b/core/Makefile index b1b3d13e8a..0d24719473 100644 --- a/core/Makefile +++ b/core/Makefile @@ -724,6 +724,9 @@ INTERNAL_USERIMAGES_BINARY_PATHS := $(sort $(dir $(INTERNAL_USERIMAGES_DEPS))) ifeq (true,$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY)) INTERNAL_USERIMAGES_DEPS += $(BUILD_VERITY_TREE) $(APPEND2SIMG) $(VERITY_SIGNER) +ifeq (true,$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY_FEC)) +INTERNAL_USERIMAGES_DEPS += $(FEC) +endif endif SELINUX_FC := $(TARGET_ROOT_OUT)/file_contexts.bin @@ -754,6 +757,7 @@ $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_BOOT_SIGNER),$(hide) echo " $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY),$(hide) echo "verity=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY)" >> $(1)) $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY),$(hide) echo "verity_key=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VERITY_SIGNING_KEY)" >> $(1)) $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY),$(hide) echo "verity_signer_cmd=$(notdir $(VERITY_SIGNER))" >> $(1)) +$(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY_FEC),$(hide) echo "verity_fec=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VERITY_FEC)" >> $(1)) $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SYSTEM_VERITY_PARTITION),$(hide) echo "system_verity_block_device=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SYSTEM_VERITY_PARTITION)" >> $(1)) $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VENDOR_VERITY_PARTITION),$(hide) echo "vendor_verity_block_device=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VENDOR_VERITY_PARTITION)" >> $(1)) $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "vboot=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT)" >> $(1)) @@ -1363,7 +1367,8 @@ OTATOOLS := $(HOST_OUT_EXECUTABLES)/minigzip \ $(HOST_OUT_EXECUTABLES)/verity_signer \ $(HOST_OUT_EXECUTABLES)/append2simg \ $(HOST_OUT_EXECUTABLES)/img2simg \ - $(HOST_OUT_EXECUTABLES)/boot_signer + $(HOST_OUT_EXECUTABLES)/boot_signer \ + $(HOST_OUT_EXECUTABLES)/fec # Shared libraries. OTATOOLS += \ diff --git a/core/config.mk b/core/config.mk index 1db3d7ae47..2b7cb7fcdc 100644 --- a/core/config.mk +++ b/core/config.mk @@ -515,6 +515,7 @@ BUILD_VERITY_TREE := $(HOST_OUT_EXECUTABLES)/build_verity_tree BOOT_SIGNER := $(HOST_OUT_EXECUTABLES)/boot_signer FUTILITY := prebuilts/misc/$(BUILD_OS)-$(HOST_PREBUILT_ARCH)/futility/futility VBOOT_SIGNER := prebuilts/misc/scripts/vboot_signer/vboot_signer.sh +FEC := $(HOST_OUT_EXECUTABLES)/fec # ACP is always for the build OS, not for the host OS ACP := $(BUILD_OUT_EXECUTABLES)/acp$(BUILD_EXECUTABLE_SUFFIX) diff --git a/core/product.mk b/core/product.mk index 2c846aa0b5..f242e829d0 100644 --- a/core/product.mk +++ b/core/product.mk @@ -100,6 +100,7 @@ _product_var_list := \ PRODUCT_SUPPORTS_BOOT_SIGNER \ PRODUCT_SUPPORTS_VBOOT \ PRODUCT_SUPPORTS_VERITY \ + PRODUCT_SUPPORTS_VERITY_FEC \ PRODUCT_OEM_PROPERTIES \ PRODUCT_SYSTEM_PROPERTY_BLACKLIST \ PRODUCT_SYSTEM_SERVER_JARS \ diff --git a/target/product/verity.mk b/target/product/verity.mk index 6676ffe31a..0badb9feb0 100644 --- a/target/product/verity.mk +++ b/target/product/verity.mk @@ -21,6 +21,7 @@ user_variant := $(filter user userdebug,$(TARGET_BUILD_VARIANT)) ifneq (,$(user_variant)) PRODUCT_SUPPORTS_BOOT_SIGNER := true PRODUCT_SUPPORTS_VERITY := true + PRODUCT_SUPPORTS_VERITY_FEC := true # The dev key is used to sign boot and recovery images, and the verity # metadata table. Actual product deliverables will be re-signed by hand. diff --git a/tools/releasetools/build_image.py b/tools/releasetools/build_image.py index 470a108248..cd750e8260 100755 --- a/tools/releasetools/build_image.py +++ b/tools/releasetools/build_image.py @@ -33,6 +33,7 @@ import tempfile OPTIONS = common.OPTIONS FIXED_SALT = "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7" +BLOCK_SIZE = 4096 def RunCommand(cmd): """Echo and run the given command. @@ -48,6 +49,14 @@ def RunCommand(cmd): print "%s" % (output.rstrip(),) return (output, p.returncode) +def GetVerityFECSize(partition_size): + cmd = "fec -s %d" % partition_size + status, output = commands.getstatusoutput(cmd) + if status: + print output + return False, 0 + return True, int(output) + def GetVerityTreeSize(partition_size): cmd = "build_verity_tree -s %d" cmd %= partition_size @@ -67,7 +76,22 @@ def GetVerityMetadataSize(partition_size): return False, 0 return True, int(output) -def AdjustPartitionSizeForVerity(partition_size): +def GetVeritySize(partition_size, fec_supported): + success, verity_tree_size = GetVerityTreeSize(partition_size) + if not success: + return 0 + success, verity_metadata_size = GetVerityMetadataSize(partition_size) + if not success: + return 0 + verity_size = verity_tree_size + verity_metadata_size + if fec_supported: + success, fec_size = GetVerityFECSize(partition_size + verity_size) + if not success: + return 0 + return verity_size + fec_size + return verity_size + +def AdjustPartitionSizeForVerity(partition_size, fec_supported): """Modifies the provided partition size to account for the verity metadata. This information is used to size the created image appropriately. @@ -76,13 +100,43 @@ def AdjustPartitionSizeForVerity(partition_size): Returns: The size of the partition adjusted for verity metadata. """ - success, verity_tree_size = GetVerityTreeSize(partition_size) - if not success: - return 0 - success, verity_metadata_size = GetVerityMetadataSize(partition_size) - if not success: - return 0 - return partition_size - verity_tree_size - verity_metadata_size + key = "%d %d" % (partition_size, fec_supported) + if key in AdjustPartitionSizeForVerity.results: + return AdjustPartitionSizeForVerity.results[key] + + hi = partition_size + if hi % BLOCK_SIZE != 0: + hi = (hi // BLOCK_SIZE) * BLOCK_SIZE + + # verity tree and fec sizes depend on the partition size, which + # means this estimate is always going to be unnecessarily small + lo = partition_size - GetVeritySize(hi, fec_supported) + result = lo + + # do a binary search for the optimal size + while lo < hi: + i = ((lo + hi) // (2 * BLOCK_SIZE)) * BLOCK_SIZE + size = i + GetVeritySize(i, fec_supported) + if size <= partition_size: + if result < i: + result = i + lo = i + BLOCK_SIZE + else: + hi = i + + AdjustPartitionSizeForVerity.results[key] = result + return result + +AdjustPartitionSizeForVerity.results = {} + +def BuildVerityFEC(sparse_image_path, verity_fec_path, prop_dict): + cmd = "fec -e %s %s" % (sparse_image_path, verity_fec_path) + print cmd + status, output = commands.getstatusoutput(cmd) + if status: + print "Could not build FEC data! Error: %s" % output + return False + return True def BuildVerityTree(sparse_image_path, verity_image_path, prop_dict): cmd = "build_verity_tree -A %s %s %s" % ( @@ -130,12 +184,12 @@ def Append2Simg(sparse_image_path, unsparse_image_path, error_message): def BuildVerifiedImage(data_image_path, verity_image_path, verity_metadata_path): - if not Append2Simg(data_image_path, verity_metadata_path, - "Could not append verity metadata!"): - return False if not Append2Simg(data_image_path, verity_image_path, "Could not append verity tree!"): return False + if not Append2Simg(data_image_path, verity_metadata_path, + "Could not append verity metadata!"): + return False return True def UnsparseImage(sparse_image_path, replace=True): @@ -154,7 +208,7 @@ def UnsparseImage(sparse_image_path, replace=True): return False, None return True, unsparse_image_path -def MakeVerityEnabledImage(out_file, prop_dict): +def MakeVerityEnabledImage(out_file, fec_supported, prop_dict): """Creates an image that is verifiable using dm-verity. Args: @@ -180,6 +234,7 @@ def MakeVerityEnabledImage(out_file, prop_dict): # get partial image paths verity_image_path = os.path.join(tempdir_name, "verity.img") verity_metadata_path = os.path.join(tempdir_name, "verity_metadata.img") + verity_fec_path = os.path.join(tempdir_name, "verity_fec.img") # build the verity tree and get the root hash and salt if not BuildVerityTree(out_file, verity_image_path, prop_dict): @@ -201,6 +256,16 @@ def MakeVerityEnabledImage(out_file, prop_dict): shutil.rmtree(tempdir_name, ignore_errors=True) return False + if fec_supported: + # build FEC for the entire partition, including metadata + if not BuildVerityFEC(out_file, verity_fec_path, prop_dict): + shutil.rmtree(tempdir_name, ignore_errors=True) + return False + + if not Append2Simg(out_file, verity_fec_path, "Could not append FEC!"): + shutil.rmtree(tempdir_name, ignore_errors=True) + return False + shutil.rmtree(tempdir_name, ignore_errors=True) return True @@ -248,12 +313,14 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None): is_verity_partition = "verity_block_device" in prop_dict verity_supported = prop_dict.get("verity") == "true" + verity_fec_supported = prop_dict.get("verity_fec") == "true" + # Adjust the partition size to make room for the hashes if this is to be # verified. if verity_supported and is_verity_partition and fs_spans_partition: partition_size = int(prop_dict.get("partition_size")) - - adjusted_size = AdjustPartitionSizeForVerity(partition_size) + adjusted_size = AdjustPartitionSizeForVerity(partition_size, + verity_fec_supported) if not adjusted_size: return False prop_dict["partition_size"] = str(adjusted_size) @@ -366,7 +433,7 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None): "%d" % (mount_point, image_size, partition_size)) return False if verity_supported and is_verity_partition: - if 2 * image_size - AdjustPartitionSizeForVerity(image_size) > partition_size: + if 2 * image_size - AdjustPartitionSizeForVerity(image_size, verity_fec_supported) > partition_size: print "Error: No more room on %s to fit verity data" % mount_point return False prop_dict["original_partition_size"] = prop_dict["partition_size"] @@ -374,7 +441,7 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None): # create the verified image if this is to be verified if verity_supported and is_verity_partition: - if not MakeVerityEnabledImage(out_file, prop_dict): + if not MakeVerityEnabledImage(out_file, verity_fec_supported, prop_dict): return False if run_fsck and prop_dict.get("skip_fsck") != "true": @@ -416,7 +483,8 @@ def ImagePropFromGlobalDict(glob_dict, mount_point): "skip_fsck", "verity", "verity_key", - "verity_signer_cmd" + "verity_signer_cmd", + "verity_fec" ) for p in common_props: copy_prop(p, p)