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#
# Copyright (C) 2018 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""Unittests for verity_utils.py."""
import copy
import math
import os.path
import random
import common
import sparse_img
from rangelib import RangeSet
from test_utils import (
get_testdata_dir, ReleaseToolsTestCase, SkipIfExternalToolsUnavailable)
from verity_utils import (
CalculateVbmetaDigest, CreateHashtreeInfoGenerator,
CreateVerityImageBuilder, HashtreeInfo,
VerifiedBootVersion1HashtreeInfoGenerator)
BLOCK_SIZE = common.BLOCK_SIZE
class VerifiedBootVersion1HashtreeInfoGeneratorTest(ReleaseToolsTestCase):
def setUp(self):
self.testdata_dir = get_testdata_dir()
self.partition_size = 1024 * 1024
self.prop_dict = {
'verity': 'true',
'verity_fec': 'true',
'system_verity_block_device': '/dev/block/system',
'system_size': self.partition_size
}
self.hash_algorithm = "sha256"
self.fixed_salt = (
"aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7")
self.expected_root_hash = (
"0b7c4565e87b1026e11fbab91c0bc29e185c847a5b44d40e6e86e461e8adf80d")
def _CreateSimg(self, raw_data): # pylint: disable=no-self-use
output_file = common.MakeTempFile()
raw_image = common.MakeTempFile()
with open(raw_image, 'wb') as f:
f.write(raw_data)
cmd = ["img2simg", raw_image, output_file, '4096']
common.RunAndCheckOutput(cmd)
return output_file
def _GenerateImage(self):
partition_size = 1024 * 1024
prop_dict = {
'partition_size': str(partition_size),
'verity': 'true',
'verity_block_device': '/dev/block/system',
'verity_key': os.path.join(self.testdata_dir, 'testkey'),
'verity_fec': 'true',
'verity_signer_cmd': 'verity_signer',
}
verity_image_builder = CreateVerityImageBuilder(prop_dict)
self.assertIsNotNone(verity_image_builder)
adjusted_size = verity_image_builder.CalculateMaxImageSize()
raw_image = bytearray(adjusted_size)
for i in range(adjusted_size):
raw_image[i] = ord('0') + i % 10
output_file = self._CreateSimg(raw_image)
# Append the verity metadata.
verity_image_builder.Build(output_file)
return output_file
@SkipIfExternalToolsUnavailable()
def test_CreateHashtreeInfoGenerator(self):
image_file = sparse_img.SparseImage(self._GenerateImage())
generator = CreateHashtreeInfoGenerator(
'system', image_file, self.prop_dict)
self.assertEqual(
VerifiedBootVersion1HashtreeInfoGenerator, type(generator))
self.assertEqual(self.partition_size, generator.partition_size)
self.assertTrue(generator.fec_supported)
@SkipIfExternalToolsUnavailable()
def test_DecomposeSparseImage(self):
image_file = sparse_img.SparseImage(self._GenerateImage())
generator = VerifiedBootVersion1HashtreeInfoGenerator(
self.partition_size, 4096, True)
generator.DecomposeSparseImage(image_file)
self.assertEqual(991232, generator.filesystem_size)
self.assertEqual(12288, generator.hashtree_size)
self.assertEqual(32768, generator.metadata_size)
@SkipIfExternalToolsUnavailable()
def test_ParseHashtreeMetadata(self):
image_file = sparse_img.SparseImage(self._GenerateImage())
generator = VerifiedBootVersion1HashtreeInfoGenerator(
self.partition_size, 4096, True)
generator.DecomposeSparseImage(image_file)
# pylint: disable=protected-access
generator._ParseHashtreeMetadata()
self.assertEqual(
self.hash_algorithm, generator.hashtree_info.hash_algorithm)
self.assertEqual(self.fixed_salt, generator.hashtree_info.salt)
self.assertEqual(self.expected_root_hash, generator.hashtree_info.root_hash)
@SkipIfExternalToolsUnavailable()
def test_ValidateHashtree_smoke(self):
generator = VerifiedBootVersion1HashtreeInfoGenerator(
self.partition_size, 4096, True)
generator.image = sparse_img.SparseImage(self._GenerateImage())
generator.hashtree_info = info = HashtreeInfo()
info.filesystem_range = RangeSet(data=[0, 991232 // 4096])
info.hashtree_range = RangeSet(
data=[991232 // 4096, (991232 + 12288) // 4096])
info.hash_algorithm = self.hash_algorithm
info.salt = self.fixed_salt
info.root_hash = self.expected_root_hash
self.assertTrue(generator.ValidateHashtree())
@SkipIfExternalToolsUnavailable()
def test_ValidateHashtree_failure(self):
generator = VerifiedBootVersion1HashtreeInfoGenerator(
self.partition_size, 4096, True)
generator.image = sparse_img.SparseImage(self._GenerateImage())
generator.hashtree_info = info = HashtreeInfo()
info.filesystem_range = RangeSet(data=[0, 991232 // 4096])
info.hashtree_range = RangeSet(
data=[991232 // 4096, (991232 + 12288) // 4096])
info.hash_algorithm = self.hash_algorithm
info.salt = self.fixed_salt
info.root_hash = "a" + self.expected_root_hash[1:]
self.assertFalse(generator.ValidateHashtree())
@SkipIfExternalToolsUnavailable()
def test_Generate(self):
image_file = sparse_img.SparseImage(self._GenerateImage())
generator = CreateHashtreeInfoGenerator('system', 4096, self.prop_dict)
info = generator.Generate(image_file)
self.assertEqual(RangeSet(data=[0, 991232 // 4096]), info.filesystem_range)
self.assertEqual(RangeSet(data=[991232 // 4096, (991232 + 12288) // 4096]),
info.hashtree_range)
self.assertEqual(self.hash_algorithm, info.hash_algorithm)
self.assertEqual(self.fixed_salt, info.salt)
self.assertEqual(self.expected_root_hash, info.root_hash)
class VerifiedBootVersion1VerityImageBuilderTest(ReleaseToolsTestCase):
DEFAULT_PARTITION_SIZE = 4096 * 1024
DEFAULT_PROP_DICT = {
'partition_size': str(DEFAULT_PARTITION_SIZE),
'verity': 'true',
'verity_block_device': '/dev/block/system',
'verity_key': os.path.join(get_testdata_dir(), 'testkey'),
'verity_fec': 'true',
'verity_signer_cmd': 'verity_signer',
}
def test_init(self):
prop_dict = copy.deepcopy(self.DEFAULT_PROP_DICT)
verity_image_builder = CreateVerityImageBuilder(prop_dict)
self.assertIsNotNone(verity_image_builder)
self.assertEqual(1, verity_image_builder.version)
def test_init_MissingProps(self):
prop_dict = copy.deepcopy(self.DEFAULT_PROP_DICT)
del prop_dict['verity']
self.assertIsNone(CreateVerityImageBuilder(prop_dict))
prop_dict = copy.deepcopy(self.DEFAULT_PROP_DICT)
del prop_dict['verity_block_device']
self.assertIsNone(CreateVerityImageBuilder(prop_dict))
@SkipIfExternalToolsUnavailable()
def test_CalculateMaxImageSize(self):
verity_image_builder = CreateVerityImageBuilder(self.DEFAULT_PROP_DICT)
size = verity_image_builder.CalculateMaxImageSize()
self.assertLess(size, self.DEFAULT_PARTITION_SIZE)
# Same result by explicitly passing the partition size.
self.assertEqual(
verity_image_builder.CalculateMaxImageSize(),
verity_image_builder.CalculateMaxImageSize(
self.DEFAULT_PARTITION_SIZE))
@staticmethod
def _BuildAndVerify(prop, verify_key):
verity_image_builder = CreateVerityImageBuilder(prop)
image_size = verity_image_builder.CalculateMaxImageSize()
# Build the sparse image with verity metadata.
input_dir = common.MakeTempDir()
image = common.MakeTempFile(suffix='.img')
cmd = ['mkuserimg_mke2fs', input_dir, image, 'ext4', '/system',
str(image_size), '-j', '0', '-s']
common.RunAndCheckOutput(cmd)
verity_image_builder.Build(image)
# Verify the verity metadata.
cmd = ['verity_verifier', image, '-mincrypt', verify_key]
common.RunAndCheckOutput(cmd)
@SkipIfExternalToolsUnavailable()
def test_Build(self):
self._BuildAndVerify(
self.DEFAULT_PROP_DICT,
os.path.join(get_testdata_dir(), 'testkey_mincrypt'))
@SkipIfExternalToolsUnavailable()
def test_Build_ValidationCheck(self):
# A validity check for the test itself: the image shouldn't be verifiable
# with wrong key.
self.assertRaises(
common.ExternalError,
self._BuildAndVerify,
self.DEFAULT_PROP_DICT,
os.path.join(get_testdata_dir(), 'verity_mincrypt'))
@SkipIfExternalToolsUnavailable()
def test_Build_FecDisabled(self):
prop_dict = copy.deepcopy(self.DEFAULT_PROP_DICT)
del prop_dict['verity_fec']
self._BuildAndVerify(
prop_dict,
os.path.join(get_testdata_dir(), 'testkey_mincrypt'))
@SkipIfExternalToolsUnavailable()
def test_Build_SquashFs(self):
verity_image_builder = CreateVerityImageBuilder(self.DEFAULT_PROP_DICT)
verity_image_builder.CalculateMaxImageSize()
# Build the sparse image with verity metadata.
input_dir = common.MakeTempDir()
image = common.MakeTempFile(suffix='.img')
cmd = ['mksquashfsimage.sh', input_dir, image, '-s']
common.RunAndCheckOutput(cmd)
verity_image_builder.PadSparseImage(image)
verity_image_builder.Build(image)
# Verify the verity metadata.
cmd = ["verity_verifier", image, '-mincrypt',
os.path.join(get_testdata_dir(), 'testkey_mincrypt')]
common.RunAndCheckOutput(cmd)
class VerifiedBootVersion2VerityImageBuilderTest(ReleaseToolsTestCase):
DEFAULT_PROP_DICT = {
'partition_size': str(4096 * 1024),
'partition_name': 'system',
'avb_avbtool': 'avbtool',
'avb_hashtree_enable': 'true',
'avb_add_hashtree_footer_args': '',
}
def test_init(self):
prop_dict = copy.deepcopy(self.DEFAULT_PROP_DICT)
verity_image_builder = CreateVerityImageBuilder(prop_dict)
self.assertIsNotNone(verity_image_builder)
self.assertEqual(2, verity_image_builder.version)
def test_init_MissingProps(self):
prop_dict = copy.deepcopy(self.DEFAULT_PROP_DICT)
del prop_dict['avb_hashtree_enable']
verity_image_builder = CreateVerityImageBuilder(prop_dict)
self.assertIsNone(verity_image_builder)
@SkipIfExternalToolsUnavailable()
def test_Build(self):
prop_dict = copy.deepcopy(self.DEFAULT_PROP_DICT)
verity_image_builder = CreateVerityImageBuilder(prop_dict)
self.assertIsNotNone(verity_image_builder)
self.assertEqual(2, verity_image_builder.version)
input_dir = common.MakeTempDir()
image_dir = common.MakeTempDir()
system_image = os.path.join(image_dir, 'system.img')
system_image_size = verity_image_builder.CalculateMaxImageSize()
cmd = ['mkuserimg_mke2fs', input_dir, system_image, 'ext4', '/system',
str(system_image_size), '-j', '0', '-s']
common.RunAndCheckOutput(cmd)
verity_image_builder.Build(system_image)
# Additionally make vbmeta image so that we can verify with avbtool.
vbmeta_image = os.path.join(image_dir, 'vbmeta.img')
cmd = ['avbtool', 'make_vbmeta_image', '--include_descriptors_from_image',
system_image, '--output', vbmeta_image]
common.RunAndCheckOutput(cmd)
# Verify the verity metadata.
cmd = ['avbtool', 'verify_image', '--image', vbmeta_image]
common.RunAndCheckOutput(cmd)
def _test_CalculateMinPartitionSize_SetUp(self):
# To test CalculateMinPartitionSize(), by using 200MB to 2GB image size.
# - 51200 = 200MB * 1024 * 1024 / 4096
# - 524288 = 2GB * 1024 * 1024 * 1024 / 4096
image_sizes = [BLOCK_SIZE * random.randint(51200, 524288) + offset
for offset in range(BLOCK_SIZE)]
prop_dict = {
'partition_size': None,
'partition_name': 'system',
'avb_avbtool': 'avbtool',
'avb_hashtree_enable': 'true',
'avb_add_hashtree_footer_args': None,
}
builder = CreateVerityImageBuilder(prop_dict)
self.assertEqual(2, builder.version)
return image_sizes, builder
def test_CalculateMinPartitionSize_LinearFooterSize(self):
"""Tests with footer size which is linear to partition size."""
image_sizes, builder = self._test_CalculateMinPartitionSize_SetUp()
for image_size in image_sizes:
for ratio in 0.95, 0.56, 0.22:
expected_size = common.RoundUpTo4K(int(math.ceil(image_size / ratio)))
self.assertEqual(
expected_size,
builder.CalculateMinPartitionSize(
image_size, lambda x, ratio=ratio: int(x * ratio)))
def test_AVBCalcMinPartitionSize_SlowerGrowthFooterSize(self):
"""Tests with footer size which grows slower than partition size."""
def _SizeCalculator(partition_size):
"""Footer size is the power of 0.95 of partition size."""
# Minus footer size to return max image size.
return partition_size - int(math.pow(partition_size, 0.95))
image_sizes, builder = self._test_CalculateMinPartitionSize_SetUp()
for image_size in image_sizes:
min_partition_size = builder.CalculateMinPartitionSize(
image_size, _SizeCalculator)
# Checks min_partition_size can accommodate image_size.
self.assertGreaterEqual(
_SizeCalculator(min_partition_size),
image_size)
# Checks min_partition_size (round to BLOCK_SIZE) is the minimum.
self.assertLess(
_SizeCalculator(min_partition_size - BLOCK_SIZE),
image_size)
def test_CalculateMinPartitionSize_FasterGrowthFooterSize(self):
"""Tests with footer size which grows faster than partition size."""
def _SizeCalculator(partition_size):
"""Max image size is the power of 0.95 of partition size."""
# Max image size grows less than partition size, which means
# footer size grows faster than partition size.
return int(math.pow(partition_size, 0.95))
image_sizes, builder = self._test_CalculateMinPartitionSize_SetUp()
for image_size in image_sizes:
min_partition_size = builder.CalculateMinPartitionSize(
image_size, _SizeCalculator)
# Checks min_partition_size can accommodate image_size.
self.assertGreaterEqual(
_SizeCalculator(min_partition_size),
image_size)
# Checks min_partition_size (round to BLOCK_SIZE) is the minimum.
self.assertLess(
_SizeCalculator(min_partition_size - BLOCK_SIZE),
image_size)
@SkipIfExternalToolsUnavailable()
def test_CalculateVbmetaDigest(self):
prop_dict = copy.deepcopy(self.DEFAULT_PROP_DICT)
verity_image_builder = CreateVerityImageBuilder(prop_dict)
self.assertEqual(2, verity_image_builder.version)
input_dir = common.MakeTempDir()
image_dir = common.MakeTempDir()
os.mkdir(os.path.join(image_dir, 'IMAGES'))
system_image = os.path.join(image_dir, 'IMAGES', 'system.img')
system_image_size = verity_image_builder.CalculateMaxImageSize()
cmd = ['mkuserimg_mke2fs', input_dir, system_image, 'ext4', '/system',
str(system_image_size), '-j', '0', '-s']
common.RunAndCheckOutput(cmd)
verity_image_builder.Build(system_image)
# Additionally make vbmeta image
vbmeta_image = os.path.join(image_dir, 'IMAGES', 'vbmeta.img')
cmd = ['avbtool', 'make_vbmeta_image', '--include_descriptors_from_image',
system_image, '--output', vbmeta_image]
common.RunAndCheckOutput(cmd)
# Verify the verity metadata.
cmd = ['avbtool', 'verify_image', '--image', vbmeta_image]
common.RunAndCheckOutput(cmd)
digest = CalculateVbmetaDigest(image_dir, 'avbtool')
self.assertIsNotNone(digest)