update_engine: Add --properties_format flag to delta_generator

We need to be able to capture information about a payload by just
looking at it. These information needed for nebraska to be able to
process a response from a request. These information includes:
- Payload and its metadata hashes and sizes.
- Payload metadata signature.
- The APP ID of the original image.
- Whether the payload is a delta or full.
- The payload's target version.

This CL adds the ability to generate a json file with the payloads
properties such as above.

Also this CL refactors how this information is generated into a single
class.

BUG=chromium:960433
TEST=delta_generator --in_file=hello-signed-delta --properties_file=prop
TEST=delta_generator --in_file=hello-signed-delta
--properties_file=payload.json --properties_format="json"

Change-Id: Ia61be0bf37bcacfd82f8982a7977fdae2f18cb30
Reviewed-on: https://chromium-review.googlesource.com/1610801
Tested-by: Amin Hassani <ahassani@chromium.org>
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Sen Jiang <senj@chromium.org>
Reviewed-by: Nicolas Norvez <norvez@chromium.org>
diff --git a/payload_generator/generate_delta_main.cc b/payload_generator/generate_delta_main.cc
index de0a091..10ae2a0 100644
--- a/payload_generator/generate_delta_main.cc
+++ b/payload_generator/generate_delta_main.cc
@@ -38,6 +38,7 @@
 #include "update_engine/payload_consumer/payload_constants.h"
 #include "update_engine/payload_generator/delta_diff_generator.h"
 #include "update_engine/payload_generator/payload_generation_config.h"
+#include "update_engine/payload_generator/payload_properties.h"
 #include "update_engine/payload_generator/payload_signer.h"
 #include "update_engine/payload_generator/xz.h"
 #include "update_engine/update_metadata.pb.h"
@@ -53,6 +54,9 @@
 
 namespace {
 
+constexpr char kPayloadPropertiesFormatKeyValue[] = "key-value";
+constexpr char kPayloadPropertiesFormatJson[] = "json";
+
 void ParseSignatureSizes(const string& signature_sizes_flag,
                          vector<int>* signature_sizes) {
   signature_sizes->clear();
@@ -268,14 +272,24 @@
   return true;
 }
 
-int ExtractProperties(const string& payload_path, const string& props_file) {
-  brillo::KeyValueStore properties;
-  TEST_AND_RETURN_FALSE(
-      PayloadSigner::ExtractPayloadProperties(payload_path, &properties));
-  if (props_file == "-") {
-    printf("%s", properties.SaveToString().c_str());
+bool ExtractProperties(const string& payload_path,
+                       const string& props_file,
+                       const string& props_format) {
+  string properties;
+  PayloadProperties payload_props(payload_path);
+  if (props_format == kPayloadPropertiesFormatKeyValue) {
+    TEST_AND_RETURN_FALSE(payload_props.GetPropertiesAsKeyValue(&properties));
+  } else if (props_format == kPayloadPropertiesFormatJson) {
+    TEST_AND_RETURN_FALSE(payload_props.GetPropertiesAsJson(&properties));
   } else {
-    properties.Save(base::FilePath(props_file));
+    LOG(FATAL) << "Invalid option " << props_format
+               << " for --properties_format flag.";
+  }
+  if (props_file == "-") {
+    printf("%s", properties.c_str());
+  } else {
+    utils::WriteFile(
+        props_file.c_str(), properties.c_str(), properties.length());
     LOG(INFO) << "Generated properties file at " << props_file;
   }
   return true;
@@ -362,7 +376,11 @@
   DEFINE_string(properties_file,
                 "",
                 "If passed, dumps the payload properties of the payload passed "
-                "in --in_file and exits.");
+                "in --in_file and exits. Look at --properties_format.");
+  DEFINE_string(properties_format,
+                kPayloadPropertiesFormatKeyValue,
+                "Defines the format of the --properties_file. The acceptable "
+                "values are: key-value (default) and json");
   DEFINE_int64(max_timestamp,
                0,
                "The maximum timestamp of the OS allowed to apply this "
@@ -467,7 +485,10 @@
     return VerifySignedPayload(FLAGS_in_file, FLAGS_public_key);
   }
   if (!FLAGS_properties_file.empty()) {
-    return ExtractProperties(FLAGS_in_file, FLAGS_properties_file) ? 0 : 1;
+    return ExtractProperties(
+               FLAGS_in_file, FLAGS_properties_file, FLAGS_properties_format)
+               ? 0
+               : 1;
   }
 
   // A payload generation was requested. Convert the flags to a
diff --git a/payload_generator/payload_properties.cc b/payload_generator/payload_properties.cc
new file mode 100644
index 0000000..53e69f3
--- /dev/null
+++ b/payload_generator/payload_properties.cc
@@ -0,0 +1,143 @@
+//
+// Copyright 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 <algorithm>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include <base/json/json_writer.h>
+#include <base/strings/string_util.h>
+#include <base/values.h>
+#include <brillo/data_encoding.h>
+
+#include "update_engine/common/constants.h"
+#include "update_engine/common/hash_calculator.h"
+#include "update_engine/common/utils.h"
+#include "update_engine/payload_consumer/payload_metadata.h"
+#include "update_engine/update_metadata.pb.h"
+
+using std::string;
+using std::vector;
+
+namespace chromeos_update_engine {
+
+namespace {
+// These ones are needed by the GoldenEye.
+const char kPayloadPropertyJsonVersion[] = "version";
+const char kPayloadPropertyJsonPayloadHash[] = "sha256_hex";
+const char kPayloadPropertyJsonMetadataSize[] = "metadata_size";
+const char kPayloadPropertyJsonMetadataSignature[] = "metadata_signature";
+
+// These are needed by the Nebraska and devserver.
+const char kPayloadPropertyJsonPayloadSize[] = "size";
+const char kPayloadPropertyJsonIsDelta[] = "is_delta";
+const char kPayloadPropertyJsonTargetVersion[] = "target_version";
+const char kPayloadPropertyJsonSourceVersion[] = "source_version";
+}  // namespace
+
+PayloadProperties::PayloadProperties(const string& payload_path)
+    : payload_path_(payload_path) {}
+
+bool PayloadProperties::GetPropertiesAsJson(string* json_str) {
+  TEST_AND_RETURN_FALSE(LoadFromPayload());
+
+  base::DictionaryValue properties;
+  properties.SetInteger(kPayloadPropertyJsonVersion, version_);
+  properties.SetInteger(kPayloadPropertyJsonMetadataSize, metadata_size_);
+  properties.SetString(kPayloadPropertyJsonMetadataSignature,
+                       metadata_signatures_);
+  properties.SetInteger(kPayloadPropertyJsonPayloadSize, payload_size_);
+  properties.SetString(kPayloadPropertyJsonPayloadHash, payload_hash_);
+  properties.SetBoolean(kPayloadPropertyJsonIsDelta, is_delta_);
+  properties.SetString(kPayloadPropertyJsonTargetVersion, target_version_);
+  if (is_delta_) {
+    properties.SetString(kPayloadPropertyJsonSourceVersion, source_version_);
+  }
+
+  return base::JSONWriter::Write(properties, json_str);
+}
+
+bool PayloadProperties::GetPropertiesAsKeyValue(string* key_value_str) {
+  TEST_AND_RETURN_FALSE(LoadFromPayload());
+
+  brillo::KeyValueStore properties;
+  properties.SetString(kPayloadPropertyFileSize, std::to_string(payload_size_));
+  properties.SetString(kPayloadPropertyMetadataSize,
+                       std::to_string(metadata_size_));
+  properties.SetString(kPayloadPropertyFileHash, payload_hash_);
+  properties.SetString(kPayloadPropertyMetadataHash, metadata_hash_);
+
+  *key_value_str = properties.SaveToString();
+  return true;
+}
+
+bool PayloadProperties::LoadFromPayload() {
+  PayloadMetadata payload_metadata;
+  DeltaArchiveManifest manifest;
+  Signatures metadata_signatures;
+  TEST_AND_RETURN_FALSE(payload_metadata.ParsePayloadFile(
+      payload_path_, &manifest, &metadata_signatures));
+
+  metadata_size_ = payload_metadata.GetMetadataSize();
+  payload_size_ = utils::FileSize(payload_path_);
+
+  brillo::Blob metadata_hash;
+  TEST_AND_RETURN_FALSE(HashCalculator::RawHashOfFile(
+                            payload_path_, metadata_size_, &metadata_hash) ==
+                        static_cast<off_t>(metadata_size_));
+  metadata_hash_ = brillo::data_encoding::Base64Encode(metadata_hash);
+
+  brillo::Blob payload_hash;
+  TEST_AND_RETURN_FALSE(HashCalculator::RawHashOfFile(
+                            payload_path_, payload_size_, &payload_hash) ==
+                        static_cast<off_t>(payload_size_));
+  payload_hash_ = brillo::data_encoding::Base64Encode(payload_hash);
+
+  if (payload_metadata.GetMetadataSignatureSize() > 0) {
+    TEST_AND_RETURN_FALSE(metadata_signatures.signatures_size() > 0);
+    vector<string> base64_signatures;
+    for (const auto& sig : metadata_signatures.signatures()) {
+      base64_signatures.push_back(
+          brillo::data_encoding::Base64Encode(sig.data()));
+    }
+    metadata_signatures_ = base::JoinString(base64_signatures, ":");
+  }
+
+  is_delta_ = manifest.has_old_image_info() || manifest.has_old_kernel_info() ||
+              manifest.has_old_rootfs_info() ||
+              std::any_of(manifest.partitions().begin(),
+                          manifest.partitions().end(),
+                          [](const PartitionUpdate& part) {
+                            return part.has_old_partition_info();
+                          });
+
+  if (manifest.has_new_image_info()) {
+    target_version_ = manifest.new_image_info().version();
+  } else {
+    target_version_ = "99999.0.0";
+  }
+
+  // No need to set the source version if it was not a delta payload.
+  if (is_delta_ && manifest.has_old_image_info()) {
+    source_version_ = manifest.old_image_info().version();
+  }
+  return true;
+}
+
+}  // namespace chromeos_update_engine
diff --git a/payload_generator/payload_properties.h b/payload_generator/payload_properties.h
new file mode 100644
index 0000000..3b34511
--- /dev/null
+++ b/payload_generator/payload_properties.h
@@ -0,0 +1,73 @@
+//
+// Copyright 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.
+//
+
+#ifndef UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_PROPERTIES_H_
+#define UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_PROPERTIES_H_
+
+#include <string>
+
+#include <brillo/key_value_store.h>
+#include <brillo/secure_blob.h>
+
+namespace chromeos_update_engine {
+
+// A class for extracting information about a payload from the payload file
+// itself. Currently the metadata can be exported as a json file or a key/value
+// properties file. But more can be added if required.
+class PayloadProperties {
+ public:
+  explicit PayloadProperties(const std::string& payload_path);
+  ~PayloadProperties() = default;
+
+  // Get the properties in a json format. The json file will be used in
+  // autotests, cros flash, etc. Mainly in Chrome OS.
+  bool GetPropertiesAsJson(std::string* json_str);
+
+  // Get the properties of the payload as a key/value store. This is mainly used
+  // in Android.
+  bool GetPropertiesAsKeyValue(std::string* key_value_str);
+
+ private:
+  // Does the main job of reading the payload and extracting information from
+  // it.
+  bool LoadFromPayload();
+
+  // The path to the payload file.
+  std::string payload_path_;
+
+  // The version of the metadata json format. If the output json file changes
+  // format, this needs to be increased.
+  int version_{2};
+
+  size_t metadata_size_;
+  std::string metadata_hash_;
+  std::string metadata_signatures_;
+
+  size_t payload_size_;
+  std::string payload_hash_;
+
+  // Whether the payload is a delta (true) or full (false).
+  bool is_delta_;
+
+  std::string target_version_;
+  std::string source_version_;
+
+  DISALLOW_COPY_AND_ASSIGN(PayloadProperties);
+};
+
+}  // namespace chromeos_update_engine
+
+#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_PROPERTIES_H_
diff --git a/payload_generator/payload_signer.cc b/payload_generator/payload_signer.cc
index 2d0489a..2a7021f 100644
--- a/payload_generator/payload_signer.cc
+++ b/payload_generator/payload_signer.cc
@@ -439,35 +439,4 @@
   return true;
 }
 
-bool PayloadSigner::ExtractPayloadProperties(
-    const string& payload_path, brillo::KeyValueStore* properties) {
-  brillo::Blob payload;
-  TEST_AND_RETURN_FALSE(
-      utils::ReadFileChunk(payload_path, 0, kMaxPayloadHeaderSize, &payload));
-
-  PayloadMetadata payload_metadata;
-  TEST_AND_RETURN_FALSE(payload_metadata.ParsePayloadHeader(payload));
-  uint64_t metadata_size = payload_metadata.GetMetadataSize();
-
-  uint64_t file_size = utils::FileSize(payload_path);
-  properties->SetString(kPayloadPropertyFileSize, std::to_string(file_size));
-  properties->SetString(kPayloadPropertyMetadataSize,
-                        std::to_string(metadata_size));
-
-  brillo::Blob file_hash, metadata_hash;
-  TEST_AND_RETURN_FALSE(
-      HashCalculator::RawHashOfFile(payload_path, file_size, &file_hash) ==
-      static_cast<off_t>(file_size));
-
-  TEST_AND_RETURN_FALSE(HashCalculator::RawHashOfFile(
-                            payload_path, metadata_size, &metadata_hash) ==
-                        static_cast<off_t>(metadata_size));
-
-  properties->SetString(kPayloadPropertyFileHash,
-                        brillo::data_encoding::Base64Encode(file_hash));
-  properties->SetString(kPayloadPropertyMetadataHash,
-                        brillo::data_encoding::Base64Encode(metadata_hash));
-  return true;
-}
-
 }  // namespace chromeos_update_engine
diff --git a/payload_generator/payload_signer.h b/payload_generator/payload_signer.h
index b2d6606..83ddadc 100644
--- a/payload_generator/payload_signer.h
+++ b/payload_generator/payload_signer.h
@@ -119,9 +119,6 @@
                                    const std::string& private_key_path,
                                    std::string* out_signature);
 
-  static bool ExtractPayloadProperties(const std::string& payload_path,
-                                       brillo::KeyValueStore* properties);
-
  private:
   // This should never be constructed
   DISALLOW_IMPLICIT_CONSTRUCTORS(PayloadSigner);