# # 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)