update_engine: Validate payload properties.

Add in unit tests to validate payload properties for JSON and KeyValue
string generation. The JSON properties string should have valid
corresponding "sha256_hex" based on the hash of the entire payload file.
The KeyValue properties string should have valid corresponding payload
and metadata hashes based on payload file size and metadata size
respectively.

BUG=None
TEST=unittests

Change-Id: I0399f420d8ee3dc1e4a103841046b91a0319cdb3
Reviewed-on: https://chromium-review.googlesource.com/1669812
Tested-by: Jae Hoon Kim <kimjae@chromium.org>
Commit-Ready: Jae Hoon Kim <kimjae@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
diff --git a/Android.bp b/Android.bp
index 0c3cac1..db33a5e 100644
--- a/Android.bp
+++ b/Android.bp
@@ -695,6 +695,7 @@
         "payload_generator/payload_file_unittest.cc",
         "payload_generator/payload_generation_config_android_unittest.cc",
         "payload_generator/payload_generation_config_unittest.cc",
+        "payload_generator/payload_properties_unittest.cc",
         "payload_generator/payload_signer_unittest.cc",
         "payload_generator/squashfs_filesystem_unittest.cc",
         "payload_generator/tarjan_unittest.cc",
diff --git a/BUILD.gn b/BUILD.gn
index 2ee0b9e..f2bddc9 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -498,6 +498,7 @@
       "payload_generator/mapfile_filesystem_unittest.cc",
       "payload_generator/payload_file_unittest.cc",
       "payload_generator/payload_generation_config_unittest.cc",
+      "payload_generator/payload_properties_unittest.cc",
       "payload_generator/payload_signer_unittest.cc",
       "payload_generator/squashfs_filesystem_unittest.cc",
       "payload_generator/tarjan_unittest.cc",
diff --git a/payload_generator/payload_properties_unittest.cc b/payload_generator/payload_properties_unittest.cc
new file mode 100644
index 0000000..db3902c
--- /dev/null
+++ b/payload_generator/payload_properties_unittest.cc
@@ -0,0 +1,144 @@
+//
+// Copyright (C) 2019 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.
+//
+
+#include "update_engine/payload_generator/payload_properties.h"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <base/files/file_util.h>
+#include <base/files/scoped_file.h>
+#include <base/files/scoped_temp_dir.h>
+#include <base/rand_util.h>
+#include <base/strings/stringprintf.h>
+#include <brillo/data_encoding.h>
+
+#include <gtest/gtest.h>
+
+#include "update_engine/common/hash_calculator.h"
+#include "update_engine/common/test_utils.h"
+#include "update_engine/common/utils.h"
+#include "update_engine/payload_consumer/install_plan.h"
+#include "update_engine/payload_generator/delta_diff_generator.h"
+#include "update_engine/payload_generator/delta_diff_utils.h"
+#include "update_engine/payload_generator/full_update_generator.h"
+#include "update_engine/payload_generator/operations_generator.h"
+#include "update_engine/payload_generator/payload_file.h"
+#include "update_engine/payload_generator/payload_generation_config.h"
+
+using chromeos_update_engine::test_utils::ScopedTempFile;
+using std::string;
+using std::unique_ptr;
+using std::vector;
+
+namespace chromeos_update_engine {
+
+// TODO(kimjae): current implementation is very specific to a static way of
+// producing a deterministic test. It would definitely be beneficial to
+// extend the |PayloadPropertiesTest::SetUp()| into a generic helper or
+// seperate class that can handle creation of different |PayloadFile|s.
+class PayloadPropertiesTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    PayloadGenerationConfig config;
+    config.version.major = kBrilloMajorPayloadVersion;
+    config.version.minor = kSourceMinorPayloadVersion;
+    config.source.image_info.set_version("123.0.0");
+    config.target.image_info.set_version("456.7.8");
+    PayloadFile payload;
+    EXPECT_TRUE(payload.Init(config));
+
+    const string kTempFileTemplate = "temp_data.XXXXXX";
+    int data_file_fd;
+    string temp_file_path;
+    EXPECT_TRUE(
+        utils::MakeTempFile(kTempFileTemplate, &temp_file_path, &data_file_fd));
+    ScopedPathUnlinker temp_file_unlinker(temp_file_path);
+    EXPECT_LE(0, data_file_fd);
+
+    const auto SetupPartitionConfig =
+        [](PartitionConfig* config, const string& path, size_t size) {
+          config->path = path;
+          config->size = size;
+        };
+    const auto WriteZerosToFile = [](const char path[], size_t size) {
+      string zeros(size, '\0');
+      EXPECT_TRUE(utils::WriteFile(path, zeros.c_str(), zeros.size()));
+    };
+    ScopedTempFile old_part_file;
+    ScopedTempFile new_part_file;
+    PartitionConfig old_part(kPartitionNameRoot);
+    PartitionConfig new_part(kPartitionNameRoot);
+    SetupPartitionConfig(&old_part, old_part_file.path(), 0);
+    SetupPartitionConfig(&new_part, new_part_file.path(), 10000);
+    WriteZerosToFile(old_part_file.path().c_str(), old_part.size);
+    WriteZerosToFile(new_part_file.path().c_str(), new_part.size);
+
+    // Select payload generation strategy based on the config.
+    unique_ptr<OperationsGenerator> strategy(new FullUpdateGenerator());
+
+    vector<AnnotatedOperation> aops;
+    off_t data_file_size = 0;
+    BlobFileWriter blob_file_writer(data_file_fd, &data_file_size);
+    // Generate the operations using the strategy we selected above.
+    EXPECT_TRUE(strategy->GenerateOperations(
+        config, old_part, new_part, &blob_file_writer, &aops));
+
+    payload.AddPartition(old_part, new_part, aops);
+
+    uint64_t metadata_size;
+    EXPECT_TRUE(payload.WritePayload(
+        payload_file.path(), temp_file_path, "", &metadata_size));
+  }
+
+  ScopedTempFile payload_file;
+};
+
+// Validate the hash of file exists within the output.
+TEST_F(PayloadPropertiesTest, GetPropertiesAsJsonTestHash) {
+  constexpr char kJsonProperties[] =
+      "{"
+      R"("is_delta":true,)"
+      R"("metadata_signature":"",)"
+      R"("metadata_size":187,)"
+      R"("sha256_hex":"Rtrj9v3xXhrAi1741HAojtGxAQEOZ7mDyhzskIF4PJc=",)"
+      R"("size":233,)"
+      R"("source_version":"123.0.0",)"
+      R"("target_version":"456.7.8",)"
+      R"("version":2)"
+      "}";
+  string json;
+  EXPECT_TRUE(
+      PayloadProperties(payload_file.path()).GetPropertiesAsJson(&json));
+  EXPECT_EQ(kJsonProperties, json) << "JSON contents:\n" << json;
+}
+
+// Validate the hash of file and metadata are within the output.
+TEST_F(PayloadPropertiesTest, GetPropertiesAsKeyValueTestHash) {
+  constexpr char kKeyValueProperties[] =
+      "FILE_HASH=Rtrj9v3xXhrAi1741HAojtGxAQEOZ7mDyhzskIF4PJc=\n"
+      "FILE_SIZE=233\n"
+      "METADATA_HASH=kiXTexy/s2aPttf4+r8KRZWYZ6FYvwhU6rJGcnnI+U0=\n"
+      "METADATA_SIZE=187\n";
+  string key_value;
+  EXPECT_TRUE(PayloadProperties{payload_file.path()}.GetPropertiesAsKeyValue(
+      &key_value));
+  EXPECT_EQ(kKeyValueProperties, key_value) << "Key Value contents:\n"
+                                            << key_value;
+}
+
+}  // namespace chromeos_update_engine