Generate the compute_hash_tree command

Generate the transfer command "compute_hash_tree" for incremental
updates of the non-A/B devices that enable verified boot 1.0

Other changes include:
i.  factor out verity_utils to use both in build_image and blockimgdiff
ii. add a new flag 'hashtree_info_generator' in sparse_image to generate
    the hashtree information.

Bug: 25170618
Test: generate a package for aosp_angler; and run simulator
Change-Id: I4d4d7a3e41dc3da810d2cbf8988e85d187c9ab0e

tools/releasetools/test_verity_utils.py

@@ -0,0 +1,168 @@
+#
+# 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."""
+
+from __future__ import print_function
+
+import os
+import os.path
+import unittest
+
+import build_image
+import common
+import sparse_img
+import test_utils
+import verity_utils
+from rangelib import RangeSet
+
+
+class VerityUtilsTest(unittest.TestCase):
+  def setUp(self):
+    self.testdata_dir = test_utils.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 tearDown(self):
+    common.Cleanup()
+
+  def _create_simg(self, raw_data):
+    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']
+    p = common.Run(cmd)
+    p.communicate()
+    self.assertEqual(0, p.returncode)
+
+    return output_file
+
+  def _generate_image(self):
+    partition_size = 1024 * 1024
+    adjusted_size, verity_size = build_image.AdjustPartitionSizeForVerity(
+        partition_size, True)
+
+    raw_image = ""
+    for i in range(adjusted_size):
+      raw_image += str(i % 10)
+
+    output_file = self._create_simg(raw_image)
+
+    # Append the verity metadata.
+    prop_dict = {
+        'partition_size': str(partition_size),
+        'image_size': str(adjusted_size),
+        'verity_block_device': '/dev/block/system',
+        'verity_key': os.path.join(self.testdata_dir, 'testkey'),
+        'verity_signer_cmd': 'verity_signer',
+        'verity_size': str(verity_size),
+    }
+    build_image.MakeVerityEnabledImage(output_file, True, prop_dict)
+
+    return output_file
+
+  def test_VerifiedBootVersion1HashtreeInfoGenerator_create(self):
+    image_file = sparse_img.SparseImage(self._generate_image())
+
+    generator = verity_utils.CreateHashtreeInfoGenerator(
+        'system', image_file, self.prop_dict)
+    self.assertEqual(
+        verity_utils.VerifiedBootVersion1HashtreeInfoGenerator, type(generator))
+    self.assertEqual(self.partition_size, generator.partition_size)
+    self.assertTrue(generator.fec_supported)
+
+  def test_VerifiedBootVersion1HashtreeInfoGenerator_decomposeImage(self):
+    image_file = sparse_img.SparseImage(self._generate_image())
+
+    generator = verity_utils.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)
+
+  def test_VerifiedBootVersion1HashtreeInfoGenerator_parseHashtreeMetadata(
+      self):
+    image_file = sparse_img.SparseImage(self._generate_image())
+    generator = verity_utils.VerifiedBootVersion1HashtreeInfoGenerator(
+        self.partition_size, 4096, True)
+    generator.DecomposeSparseImage(image_file)
+
+    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)
+
+  def test_VerifiedBootVersion1HashtreeInfoGenerator_validateHashtree_smoke(
+      self):
+    generator = verity_utils.VerifiedBootVersion1HashtreeInfoGenerator(
+        self.partition_size, 4096, True)
+    generator.image = sparse_img.SparseImage(self._generate_image())
+
+    generator.hashtree_info = info = verity_utils.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())
+
+  def test_VerifiedBootVersion1HashtreeInfoGenerator_validateHashtree_failure(
+      self):
+    generator = verity_utils.VerifiedBootVersion1HashtreeInfoGenerator(
+        self.partition_size, 4096, True)
+    generator.image = sparse_img.SparseImage(self._generate_image())
+
+    generator.hashtree_info = info = verity_utils.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())
+
+  def test_VerifiedBootVersion1HashtreeInfoGenerator_generate(self):
+    image_file = sparse_img.SparseImage(self._generate_image())
+    generator = verity_utils.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)