bbde59f9eb
Calculate the vbmeta digest if the device builds vbmeta image. The digest will used later to determine the build fingerprint in new format. One sample usage is the ota package generation, where we put the build fingerprint in the ota metadata. But we don't have the runtime vbmeta digest provided the bootloader. Bug: 186786987 Test: unit tests Change-Id: If572e2b973e295a6c95a9e23a65bb20b3afbf1b0
802 lines
26 KiB
Python
802 lines
26 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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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.
|
|
"""
|
|
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()
|