808 lines
27 KiB
Python
808 lines
27 KiB
Python
#!/usr/bin/env python
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#
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# Copyright (C) 2018 The Android Open Source Project
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""
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Signs a given image using avbtool
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Usage: verity_utils properties_file output_image
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"""
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from __future__ import print_function
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import logging
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import os.path
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import shlex
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import struct
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import sys
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import common
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import sparse_img
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from rangelib import RangeSet
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logger = logging.getLogger(__name__)
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OPTIONS = common.OPTIONS
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BLOCK_SIZE = common.BLOCK_SIZE
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FIXED_SALT = "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7"
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# From external/avb/avbtool.py
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MAX_VBMETA_SIZE = 64 * 1024
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MAX_FOOTER_SIZE = 4096
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class BuildVerityImageError(Exception):
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"""An Exception raised during verity image building."""
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def __init__(self, message):
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Exception.__init__(self, message)
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def GetVerityFECSize(image_size):
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cmd = ["fec", "-s", str(image_size)]
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output = common.RunAndCheckOutput(cmd, verbose=False)
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return int(output)
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def GetVerityTreeSize(image_size):
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cmd = ["build_verity_tree", "-s", str(image_size)]
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output = common.RunAndCheckOutput(cmd, verbose=False)
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return int(output)
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def GetVerityMetadataSize(image_size):
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cmd = ["build_verity_metadata", "size", str(image_size)]
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output = common.RunAndCheckOutput(cmd, verbose=False)
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return int(output)
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def GetVeritySize(image_size, fec_supported):
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verity_tree_size = GetVerityTreeSize(image_size)
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verity_metadata_size = GetVerityMetadataSize(image_size)
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verity_size = verity_tree_size + verity_metadata_size
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if fec_supported:
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fec_size = GetVerityFECSize(image_size + verity_size)
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return verity_size + fec_size
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return verity_size
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def GetSimgSize(image_file):
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simg = sparse_img.SparseImage(image_file, build_map=False)
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return simg.blocksize * simg.total_blocks
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def ZeroPadSimg(image_file, pad_size):
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blocks = pad_size // BLOCK_SIZE
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logger.info("Padding %d blocks (%d bytes)", blocks, pad_size)
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simg = sparse_img.SparseImage(image_file, mode="r+b", build_map=False)
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simg.AppendFillChunk(0, blocks)
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def BuildVerityFEC(sparse_image_path, verity_path, verity_fec_path,
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padding_size):
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cmd = ["fec", "-e", "-p", str(padding_size), sparse_image_path,
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verity_path, verity_fec_path]
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common.RunAndCheckOutput(cmd)
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def BuildVerityTree(sparse_image_path, verity_image_path):
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cmd = ["build_verity_tree", "-A", FIXED_SALT, sparse_image_path,
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verity_image_path]
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output = common.RunAndCheckOutput(cmd)
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root, salt = output.split()
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return root, salt
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def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
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block_device, signer_path, key, signer_args,
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verity_disable):
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cmd = ["build_verity_metadata", "build", str(image_size),
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verity_metadata_path, root_hash, salt, block_device, signer_path, key]
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if signer_args:
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cmd.append("--signer_args=\"%s\"" % (' '.join(signer_args),))
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if verity_disable:
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cmd.append("--verity_disable")
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common.RunAndCheckOutput(cmd)
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def Append2Simg(sparse_image_path, unsparse_image_path, error_message):
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"""Appends the unsparse image to the given sparse image.
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Args:
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sparse_image_path: the path to the (sparse) image
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unsparse_image_path: the path to the (unsparse) image
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Raises:
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BuildVerityImageError: On error.
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"""
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cmd = ["append2simg", sparse_image_path, unsparse_image_path]
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try:
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common.RunAndCheckOutput(cmd)
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except:
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logger.exception(error_message)
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raise BuildVerityImageError(error_message)
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def Append(target, file_to_append, error_message):
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"""Appends file_to_append to target.
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Raises:
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BuildVerityImageError: On error.
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"""
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try:
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with open(target, 'ab') as out_file, \
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open(file_to_append, 'rb') as input_file:
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for line in input_file:
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out_file.write(line)
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except IOError:
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logger.exception(error_message)
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raise BuildVerityImageError(error_message)
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def CreateVerityImageBuilder(prop_dict):
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"""Returns a verity image builder based on the given build properties.
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Args:
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prop_dict: A dict that contains the build properties. In particular, it will
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look for verity-related property values.
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Returns:
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A VerityImageBuilder instance for Verified Boot 1.0 or Verified Boot 2.0; or
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None if the given build doesn't support Verified Boot.
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"""
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partition_size = prop_dict.get("partition_size")
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# partition_size could be None at this point, if using dynamic partitions.
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if partition_size:
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partition_size = int(partition_size)
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# Verified Boot 1.0
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verity_supported = prop_dict.get("verity") == "true"
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is_verity_partition = "verity_block_device" in prop_dict
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if verity_supported and is_verity_partition:
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if OPTIONS.verity_signer_path is not None:
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signer_path = OPTIONS.verity_signer_path
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else:
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signer_path = prop_dict["verity_signer_cmd"]
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return Version1VerityImageBuilder(
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partition_size,
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prop_dict["verity_block_device"],
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prop_dict.get("verity_fec") == "true",
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signer_path,
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prop_dict["verity_key"] + ".pk8",
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OPTIONS.verity_signer_args,
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"verity_disable" in prop_dict)
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# Verified Boot 2.0
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if (prop_dict.get("avb_hash_enable") == "true" or
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prop_dict.get("avb_hashtree_enable") == "true"):
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# key_path and algorithm are only available when chain partition is used.
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key_path = prop_dict.get("avb_key_path")
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algorithm = prop_dict.get("avb_algorithm")
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# Image uses hash footer.
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if prop_dict.get("avb_hash_enable") == "true":
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return VerifiedBootVersion2VerityImageBuilder(
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prop_dict["partition_name"],
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partition_size,
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VerifiedBootVersion2VerityImageBuilder.AVB_HASH_FOOTER,
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prop_dict["avb_avbtool"],
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key_path,
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algorithm,
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prop_dict.get("avb_salt"),
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prop_dict["avb_add_hash_footer_args"])
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# Image uses hashtree footer.
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return VerifiedBootVersion2VerityImageBuilder(
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prop_dict["partition_name"],
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partition_size,
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VerifiedBootVersion2VerityImageBuilder.AVB_HASHTREE_FOOTER,
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prop_dict["avb_avbtool"],
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key_path,
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algorithm,
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prop_dict.get("avb_salt"),
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prop_dict["avb_add_hashtree_footer_args"])
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return None
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class VerityImageBuilder(object):
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"""A builder that generates an image with verity metadata for Verified Boot.
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A VerityImageBuilder instance handles the works for building an image with
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verity metadata for supporting Android Verified Boot. This class defines the
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common interface between Verified Boot 1.0 and Verified Boot 2.0. A matching
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builder will be returned based on the given build properties.
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More info on the verity image generation can be found at the following link.
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https://source.android.com/security/verifiedboot/dm-verity#implementation
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"""
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def CalculateMaxImageSize(self, partition_size):
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"""Calculates the filesystem image size for the given partition size."""
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raise NotImplementedError
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def CalculateDynamicPartitionSize(self, image_size):
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"""Calculates and sets the partition size for a dynamic partition."""
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raise NotImplementedError
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def PadSparseImage(self, out_file):
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"""Adds padding to the generated sparse image."""
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raise NotImplementedError
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def Build(self, out_file):
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"""Builds the verity image and writes it to the given file."""
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raise NotImplementedError
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class Version1VerityImageBuilder(VerityImageBuilder):
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"""A VerityImageBuilder for Verified Boot 1.0."""
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def __init__(self, partition_size, block_dev, fec_supported, signer_path,
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signer_key, signer_args, verity_disable):
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self.version = 1
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self.partition_size = partition_size
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self.block_device = block_dev
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self.fec_supported = fec_supported
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self.signer_path = signer_path
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self.signer_key = signer_key
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self.signer_args = signer_args
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self.verity_disable = verity_disable
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self.image_size = None
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self.verity_size = None
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def CalculateDynamicPartitionSize(self, image_size):
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# This needs to be implemented. Note that returning the given image size as
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# the partition size doesn't make sense, as it will fail later.
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raise NotImplementedError
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def CalculateMaxImageSize(self, partition_size=None):
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"""Calculates the max image size by accounting for the verity metadata.
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Args:
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partition_size: The partition size, which defaults to self.partition_size
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if unspecified.
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Returns:
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The size of the image adjusted for verity metadata.
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"""
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if partition_size is None:
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partition_size = self.partition_size
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assert partition_size > 0, \
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"Invalid partition size: {}".format(partition_size)
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hi = partition_size
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if hi % BLOCK_SIZE != 0:
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hi = (hi // BLOCK_SIZE) * BLOCK_SIZE
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# verity tree and fec sizes depend on the partition size, which
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# means this estimate is always going to be unnecessarily small
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verity_size = GetVeritySize(hi, self.fec_supported)
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lo = partition_size - verity_size
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result = lo
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# do a binary search for the optimal size
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while lo < hi:
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i = ((lo + hi) // (2 * BLOCK_SIZE)) * BLOCK_SIZE
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v = GetVeritySize(i, self.fec_supported)
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if i + v <= partition_size:
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if result < i:
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result = i
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verity_size = v
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lo = i + BLOCK_SIZE
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else:
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hi = i
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self.image_size = result
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self.verity_size = verity_size
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logger.info(
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"Calculated image size for verity: partition_size %d, image_size %d, "
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"verity_size %d", partition_size, result, verity_size)
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return result
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def Build(self, out_file):
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"""Creates an image that is verifiable using dm-verity.
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Args:
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out_file: the output image.
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Returns:
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AssertionError: On invalid partition sizes.
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BuildVerityImageError: On other errors.
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"""
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image_size = int(self.image_size)
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tempdir_name = common.MakeTempDir(suffix="_verity_images")
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# Get partial image paths.
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verity_image_path = os.path.join(tempdir_name, "verity.img")
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verity_metadata_path = os.path.join(tempdir_name, "verity_metadata.img")
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# Build the verity tree and get the root hash and salt.
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root_hash, salt = BuildVerityTree(out_file, verity_image_path)
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# Build the metadata blocks.
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BuildVerityMetadata(
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image_size, verity_metadata_path, root_hash, salt, self.block_device,
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self.signer_path, self.signer_key, self.signer_args,
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self.verity_disable)
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padding_size = self.partition_size - self.image_size - self.verity_size
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assert padding_size >= 0
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# Build the full verified image.
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Append(
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verity_image_path, verity_metadata_path,
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"Failed to append verity metadata")
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if self.fec_supported:
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# Build FEC for the entire partition, including metadata.
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verity_fec_path = os.path.join(tempdir_name, "verity_fec.img")
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BuildVerityFEC(
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out_file, verity_image_path, verity_fec_path, padding_size)
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Append(verity_image_path, verity_fec_path, "Failed to append FEC")
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Append2Simg(
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out_file, verity_image_path, "Failed to append verity data")
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def PadSparseImage(self, out_file):
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sparse_image_size = GetSimgSize(out_file)
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if sparse_image_size > self.image_size:
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raise BuildVerityImageError(
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"Error: image size of {} is larger than partition size of "
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"{}".format(sparse_image_size, self.image_size))
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ZeroPadSimg(out_file, self.image_size - sparse_image_size)
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class VerifiedBootVersion2VerityImageBuilder(VerityImageBuilder):
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"""A VerityImageBuilder for Verified Boot 2.0."""
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AVB_HASH_FOOTER = 1
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AVB_HASHTREE_FOOTER = 2
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def __init__(self, partition_name, partition_size, footer_type, avbtool,
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key_path, algorithm, salt, signing_args):
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self.version = 2
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self.partition_name = partition_name
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self.partition_size = partition_size
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self.footer_type = footer_type
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self.avbtool = avbtool
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self.algorithm = algorithm
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self.key_path = key_path
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if key_path and not os.path.exists(key_path) and OPTIONS.search_path:
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new_key_path = os.path.join(OPTIONS.search_path, key_path)
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if os.path.exists(new_key_path):
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self.key_path = new_key_path
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self.salt = salt
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self.signing_args = signing_args
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self.image_size = None
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def CalculateMinPartitionSize(self, image_size, size_calculator=None):
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"""Calculates min partition size for a given image size.
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This is used when determining the partition size for a dynamic partition,
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which should be cover the given image size (for filesystem files) as well as
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the verity metadata size.
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Args:
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image_size: The size of the image in question.
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size_calculator: The function to calculate max image size
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for a given partition size.
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Returns:
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The minimum partition size required to accommodate the image size.
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"""
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if size_calculator is None:
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size_calculator = self.CalculateMaxImageSize
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# Use image size as partition size to approximate final partition size.
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image_ratio = size_calculator(image_size) / float(image_size)
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# Prepare a binary search for the optimal partition size.
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lo = int(image_size / image_ratio) // BLOCK_SIZE * BLOCK_SIZE - BLOCK_SIZE
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# Ensure lo is small enough: max_image_size should <= image_size.
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delta = BLOCK_SIZE
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max_image_size = size_calculator(lo)
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while max_image_size > image_size:
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image_ratio = max_image_size / float(lo)
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lo = int(image_size / image_ratio) // BLOCK_SIZE * BLOCK_SIZE - delta
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delta *= 2
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max_image_size = size_calculator(lo)
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hi = lo + BLOCK_SIZE
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# Ensure hi is large enough: max_image_size should >= image_size.
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delta = BLOCK_SIZE
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max_image_size = size_calculator(hi)
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while max_image_size < image_size:
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image_ratio = max_image_size / float(hi)
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hi = int(image_size / image_ratio) // BLOCK_SIZE * BLOCK_SIZE + delta
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delta *= 2
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max_image_size = size_calculator(hi)
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partition_size = hi
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# Start to binary search.
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while lo < hi:
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mid = ((lo + hi) // (2 * BLOCK_SIZE)) * BLOCK_SIZE
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max_image_size = size_calculator(mid)
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if max_image_size >= image_size: # if mid can accommodate image_size
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if mid < partition_size: # if a smaller partition size is found
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partition_size = mid
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hi = mid
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else:
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lo = mid + BLOCK_SIZE
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logger.info(
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"CalculateMinPartitionSize(%d): partition_size %d.", image_size,
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partition_size)
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return partition_size
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def CalculateDynamicPartitionSize(self, image_size):
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self.partition_size = self.CalculateMinPartitionSize(image_size)
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return self.partition_size
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def CalculateMaxImageSize(self, partition_size=None):
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"""Calculates max image size for a given partition size.
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Args:
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partition_size: The partition size, which defaults to self.partition_size
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if unspecified.
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Returns:
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The maximum image size.
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Raises:
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BuildVerityImageError: On error or getting invalid image size.
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"""
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if partition_size is None:
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partition_size = self.partition_size
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assert partition_size > 0, \
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"Invalid partition size: {}".format(partition_size)
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add_footer = ("add_hash_footer" if self.footer_type == self.AVB_HASH_FOOTER
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else "add_hashtree_footer")
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cmd = [self.avbtool, add_footer, "--partition_size",
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str(partition_size), "--calc_max_image_size"]
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cmd.extend(shlex.split(self.signing_args))
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proc = common.Run(cmd)
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output, _ = proc.communicate()
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if proc.returncode != 0:
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raise BuildVerityImageError(
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"Failed to calculate max image size:\n{}".format(output))
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image_size = int(output)
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if image_size <= 0:
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raise BuildVerityImageError(
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"Invalid max image size: {}".format(output))
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self.image_size = image_size
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return image_size
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def PadSparseImage(self, out_file):
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# No-op as the padding is taken care of by avbtool.
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pass
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def Build(self, out_file):
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"""Adds dm-verity hashtree and AVB metadata to an image.
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Args:
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out_file: Path to image to modify.
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"""
|
|
add_footer = ("add_hash_footer" if self.footer_type == self.AVB_HASH_FOOTER
|
|
else "add_hashtree_footer")
|
|
cmd = [self.avbtool, add_footer,
|
|
"--partition_size", str(self.partition_size),
|
|
"--partition_name", self.partition_name,
|
|
"--image", out_file]
|
|
if self.key_path and self.algorithm:
|
|
cmd.extend(["--key", self.key_path, "--algorithm", self.algorithm])
|
|
if self.salt:
|
|
cmd.extend(["--salt", self.salt])
|
|
cmd.extend(shlex.split(self.signing_args))
|
|
|
|
proc = common.Run(cmd)
|
|
output, _ = proc.communicate()
|
|
if proc.returncode != 0:
|
|
raise BuildVerityImageError("Failed to add AVB footer: {}".format(output))
|
|
|
|
|
|
class HashtreeInfoGenerationError(Exception):
|
|
"""An Exception raised during hashtree info generation."""
|
|
|
|
def __init__(self, message):
|
|
Exception.__init__(self, message)
|
|
|
|
|
|
class HashtreeInfo(object):
|
|
def __init__(self):
|
|
self.hashtree_range = None
|
|
self.filesystem_range = None
|
|
self.hash_algorithm = None
|
|
self.salt = None
|
|
self.root_hash = None
|
|
|
|
|
|
def CreateHashtreeInfoGenerator(partition_name, block_size, info_dict):
|
|
generator = None
|
|
if (info_dict.get("verity") == "true" and
|
|
info_dict.get("{}_verity_block_device".format(partition_name))):
|
|
partition_size = info_dict["{}_size".format(partition_name)]
|
|
fec_supported = info_dict.get("verity_fec") == "true"
|
|
generator = VerifiedBootVersion1HashtreeInfoGenerator(
|
|
partition_size, block_size, fec_supported)
|
|
|
|
return generator
|
|
|
|
|
|
class HashtreeInfoGenerator(object):
|
|
def Generate(self, image):
|
|
raise NotImplementedError
|
|
|
|
def DecomposeSparseImage(self, image):
|
|
raise NotImplementedError
|
|
|
|
def ValidateHashtree(self):
|
|
raise NotImplementedError
|
|
|
|
|
|
class VerifiedBootVersion1HashtreeInfoGenerator(HashtreeInfoGenerator):
|
|
"""A class that parses the metadata of hashtree for a given partition."""
|
|
|
|
def __init__(self, partition_size, block_size, fec_supported):
|
|
"""Initialize VerityTreeInfo with the sparse image and input property.
|
|
|
|
Arguments:
|
|
partition_size: The whole size in bytes of a partition, including the
|
|
filesystem size, padding size, and verity size.
|
|
block_size: Expected size in bytes of each block for the sparse image.
|
|
fec_supported: True if the verity section contains fec data.
|
|
"""
|
|
|
|
self.block_size = block_size
|
|
self.partition_size = partition_size
|
|
self.fec_supported = fec_supported
|
|
|
|
self.image = None
|
|
self.filesystem_size = None
|
|
self.hashtree_size = None
|
|
self.metadata_size = None
|
|
|
|
prop_dict = {
|
|
'partition_size': str(partition_size),
|
|
'verity': 'true',
|
|
'verity_fec': 'true' if fec_supported else None,
|
|
# 'verity_block_device' needs to be present to indicate a verity-enabled
|
|
# partition.
|
|
'verity_block_device': '',
|
|
# We don't need the following properties that are needed for signing the
|
|
# verity metadata.
|
|
'verity_key': '',
|
|
'verity_signer_cmd': None,
|
|
}
|
|
self.verity_image_builder = CreateVerityImageBuilder(prop_dict)
|
|
|
|
self.hashtree_info = HashtreeInfo()
|
|
|
|
def DecomposeSparseImage(self, image):
|
|
"""Calculate the verity size based on the size of the input image.
|
|
|
|
Since we already know the structure of a verity enabled image to be:
|
|
[filesystem, verity_hashtree, verity_metadata, fec_data]. We can then
|
|
calculate the size and offset of each section.
|
|
"""
|
|
|
|
self.image = image
|
|
assert self.block_size == image.blocksize
|
|
assert self.partition_size == image.total_blocks * self.block_size, \
|
|
"partition size {} doesn't match with the calculated image size." \
|
|
" total_blocks: {}".format(self.partition_size, image.total_blocks)
|
|
|
|
adjusted_size = self.verity_image_builder.CalculateMaxImageSize()
|
|
assert adjusted_size % self.block_size == 0
|
|
|
|
verity_tree_size = GetVerityTreeSize(adjusted_size)
|
|
assert verity_tree_size % self.block_size == 0
|
|
|
|
metadata_size = GetVerityMetadataSize(adjusted_size)
|
|
assert metadata_size % self.block_size == 0
|
|
|
|
self.filesystem_size = adjusted_size
|
|
self.hashtree_size = verity_tree_size
|
|
self.metadata_size = metadata_size
|
|
|
|
self.hashtree_info.filesystem_range = RangeSet(
|
|
data=[0, adjusted_size // self.block_size])
|
|
self.hashtree_info.hashtree_range = RangeSet(
|
|
data=[adjusted_size // self.block_size,
|
|
(adjusted_size + verity_tree_size) // self.block_size])
|
|
|
|
def _ParseHashtreeMetadata(self):
|
|
"""Parses the hash_algorithm, root_hash, salt from the metadata block."""
|
|
|
|
metadata_start = self.filesystem_size + self.hashtree_size
|
|
metadata_range = RangeSet(
|
|
data=[metadata_start // self.block_size,
|
|
(metadata_start + self.metadata_size) // self.block_size])
|
|
meta_data = b''.join(self.image.ReadRangeSet(metadata_range))
|
|
|
|
# More info about the metadata structure available in:
|
|
# system/extras/verity/build_verity_metadata.py
|
|
META_HEADER_SIZE = 268
|
|
header_bin = meta_data[0:META_HEADER_SIZE]
|
|
header = struct.unpack("II256sI", header_bin)
|
|
|
|
# header: magic_number, version, signature, table_len
|
|
assert header[0] == 0xb001b001, header[0]
|
|
table_len = header[3]
|
|
verity_table = meta_data[META_HEADER_SIZE: META_HEADER_SIZE + table_len]
|
|
table_entries = verity_table.rstrip().split()
|
|
|
|
# Expected verity table format: "1 block_device block_device block_size
|
|
# block_size data_blocks data_blocks hash_algorithm root_hash salt"
|
|
assert len(table_entries) == 10, "Unexpected verity table size {}".format(
|
|
len(table_entries))
|
|
assert (int(table_entries[3]) == self.block_size and
|
|
int(table_entries[4]) == self.block_size)
|
|
assert (int(table_entries[5]) * self.block_size == self.filesystem_size and
|
|
int(table_entries[6]) * self.block_size == self.filesystem_size)
|
|
|
|
self.hashtree_info.hash_algorithm = table_entries[7].decode()
|
|
self.hashtree_info.root_hash = table_entries[8].decode()
|
|
self.hashtree_info.salt = table_entries[9].decode()
|
|
|
|
def ValidateHashtree(self):
|
|
"""Checks that we can reconstruct the verity hash tree."""
|
|
|
|
# Writes the filesystem section to a temp file; and calls the executable
|
|
# build_verity_tree to construct the hash tree.
|
|
adjusted_partition = common.MakeTempFile(prefix="adjusted_partition")
|
|
with open(adjusted_partition, "wb") as fd:
|
|
self.image.WriteRangeDataToFd(self.hashtree_info.filesystem_range, fd)
|
|
|
|
generated_verity_tree = common.MakeTempFile(prefix="verity")
|
|
root_hash, salt = BuildVerityTree(adjusted_partition, generated_verity_tree)
|
|
|
|
# The salt should be always identical, as we use fixed value.
|
|
assert salt == self.hashtree_info.salt, \
|
|
"Calculated salt {} doesn't match the one in metadata {}".format(
|
|
salt, self.hashtree_info.salt)
|
|
|
|
if root_hash != self.hashtree_info.root_hash:
|
|
logger.warning(
|
|
"Calculated root hash %s doesn't match the one in metadata %s",
|
|
root_hash, self.hashtree_info.root_hash)
|
|
return False
|
|
|
|
# Reads the generated hash tree and checks if it has the exact same bytes
|
|
# as the one in the sparse image.
|
|
with open(generated_verity_tree, 'rb') as fd:
|
|
return fd.read() == b''.join(self.image.ReadRangeSet(
|
|
self.hashtree_info.hashtree_range))
|
|
|
|
def Generate(self, image):
|
|
"""Parses and validates the hashtree info in a sparse image.
|
|
|
|
Returns:
|
|
hashtree_info: The information needed to reconstruct the hashtree.
|
|
|
|
Raises:
|
|
HashtreeInfoGenerationError: If we fail to generate the exact bytes of
|
|
the hashtree.
|
|
"""
|
|
|
|
self.DecomposeSparseImage(image)
|
|
self._ParseHashtreeMetadata()
|
|
|
|
if not self.ValidateHashtree():
|
|
raise HashtreeInfoGenerationError("Failed to reconstruct the verity tree")
|
|
|
|
return self.hashtree_info
|
|
|
|
|
|
def CreateCustomImageBuilder(info_dict, partition_name, partition_size,
|
|
key_path, algorithm, signing_args):
|
|
builder = None
|
|
if info_dict.get("avb_enable") == "true":
|
|
builder = VerifiedBootVersion2VerityImageBuilder(
|
|
partition_name,
|
|
partition_size,
|
|
VerifiedBootVersion2VerityImageBuilder.AVB_HASHTREE_FOOTER,
|
|
info_dict.get("avb_avbtool"),
|
|
key_path,
|
|
algorithm,
|
|
# Salt is None because custom images have no fingerprint property to be
|
|
# used as the salt.
|
|
None,
|
|
signing_args)
|
|
|
|
return builder
|
|
|
|
|
|
def GetDiskUsage(path):
|
|
"""Returns the number of bytes that "path" occupies on host.
|
|
|
|
Args:
|
|
path: The directory or file to calculate size on.
|
|
|
|
Returns:
|
|
The number of bytes based on a 1K block_size.
|
|
"""
|
|
cmd = ["du", "-b", "-k", "-s", path]
|
|
output = common.RunAndCheckOutput(cmd, verbose=False)
|
|
return int(output.split()[0]) * 1024
|
|
|
|
|
|
def CalculateVbmetaDigest(extracted_dir, avbtool):
|
|
"""Calculates the vbmeta digest of the images in the extracted target_file"""
|
|
|
|
images_dir = common.MakeTempDir()
|
|
for name in ("PREBUILT_IMAGES", "RADIO", "IMAGES"):
|
|
path = os.path.join(extracted_dir, name)
|
|
if not os.path.exists(path):
|
|
continue
|
|
|
|
# Create symlink for image files under PREBUILT_IMAGES, RADIO and IMAGES,
|
|
# and put them into one directory.
|
|
for filename in os.listdir(path):
|
|
if not filename.endswith(".img"):
|
|
continue
|
|
symlink_path = os.path.join(images_dir, filename)
|
|
# The files in latter directory overwrite the existing links
|
|
common.RunAndCheckOutput(
|
|
['ln', '-sf', os.path.join(path, filename), symlink_path])
|
|
|
|
cmd = [avbtool, "calculate_vbmeta_digest", "--image",
|
|
os.path.join(images_dir, 'vbmeta.img')]
|
|
return common.RunAndCheckOutput(cmd)
|
|
|
|
|
|
def main(argv):
|
|
if len(argv) != 2:
|
|
print(__doc__)
|
|
sys.exit(1)
|
|
|
|
common.InitLogging()
|
|
|
|
dict_file = argv[0]
|
|
out_file = argv[1]
|
|
|
|
prop_dict = {}
|
|
with open(dict_file, 'r') as f:
|
|
for line in f:
|
|
line = line.strip()
|
|
if not line or line.startswith("#"):
|
|
continue
|
|
k, v = line.split("=", 1)
|
|
prop_dict[k] = v
|
|
|
|
builder = CreateVerityImageBuilder(prop_dict)
|
|
|
|
if "partition_size" not in prop_dict:
|
|
image_size = GetDiskUsage(out_file)
|
|
# make sure that the image is big enough to hold vbmeta and footer
|
|
image_size = image_size + (MAX_VBMETA_SIZE + MAX_FOOTER_SIZE)
|
|
size = builder.CalculateDynamicPartitionSize(image_size)
|
|
prop_dict["partition_size"] = size
|
|
|
|
builder.Build(out_file)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
try:
|
|
main(sys.argv[1:])
|
|
finally:
|
|
common.Cleanup()
|