[EasyUnlock] Serialize and store BeaconSeeds along as cryptohome key metadata.

chrome/browser/signin/easy_unlock_service_signin_chromeos.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/signin/easy_unlock_service_signin_chromeos.h"
 
 #include <stdint.h>
 
 #include "base/base64url.h"
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/json/json_string_value_serializer.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/sys_info.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "chrome/browser/chromeos/login/easy_unlock/easy_unlock_challenge_wrapper.h"
 #include "chrome/browser/chromeos/login/easy_unlock/easy_unlock_key_manager.h"
 #include "chrome/browser/chromeos/login/easy_unlock/easy_unlock_tpm_key_manager.h"
 #include "chrome/browser/chromeos/login/easy_unlock/easy_unlock_tpm_key_manager_factory.h"
@@ skipping 64 matching lines @@
     const chromeos::EasyUnlockKeyManager::GetDeviceDataListCallback& callback) {
   chromeos::EasyUnlockKeyManager* key_manager =
       chromeos::UserSessionManager::GetInstance()->GetEasyUnlockKeyManager();
   DCHECK(key_manager);
 
   key_manager->GetDeviceDataList(
       chromeos::UserContext(account_id),
       base::Bind(&RetryDataLoadOnError, account_id, backoff_ms, callback));
 }
 
+// Deserializes a vector of BeaconSeeds. If an error occurs, an empty vector
+// will be returned. Note: The logic to serialize BeaconSeeds lives in
+// EasyUnlockServiceRegular.
+// Note: The serialization of device data inside a user session is different
+// than outside the user session (sign-in). RemoteDevices are serialized as
+// protocol buffers inside the user session, but we have a custom serialization
+// scheme for sign-in due to slightly different data requirements.
+std::vector<cryptauth::BeaconSeed> DeserializeBeaconSeeds(
+    const std::string& serialized_beacon_seeds) {
+  std::vector<cryptauth::BeaconSeed> beacon_seeds;
+
+  JSONStringValueDeserializer deserializer(serialized_beacon_seeds);
+  std::string error;
+  std::unique_ptr<base::Value> deserialized_value =
+      deserializer.Deserialize(nullptr, &error);
+  if (!deserialized_value) {
+    PA_LOG(ERROR) << "Unable to deserialize BeaconSeeds: " << error;
+    return beacon_seeds;
+  }
+
+  base::ListValue* beacon_seed_list;
+  if (!deserialized_value->GetAsList(&beacon_seed_list)) {
+    PA_LOG(ERROR) << "Deserialized BeaconSeeds value is not list.";
+    return beacon_seeds;
+  }
+
+  for (size_t i = 0; i < beacon_seed_list->GetSize(); ++i) {
+    std::string b64_beacon_seed;
+    if (!beacon_seed_list->GetString(i, &b64_beacon_seed)) {
+      PA_LOG(ERROR) << "Expected Base64 BeaconSeed.";
+      continue;
+    }
+
+    std::string proto_serialized_beacon_seed;
+    if (!base::Base64UrlDecode(b64_beacon_seed,
+                               base::Base64UrlDecodePolicy::REQUIRE_PADDING,
+                               &proto_serialized_beacon_seed)) {
+      PA_LOG(ERROR) << "Unable to decode BeaconSeed.";
+      continue;
+    }
+
+    cryptauth::BeaconSeed beacon_seed;
+    if (!beacon_seed.ParseFromString(proto_serialized_beacon_seed)) {
+      PA_LOG(ERROR) << "Unable to parse BeaconSeed proto.";
+      continue;
+    }
+
+    beacon_seeds.push_back(beacon_seed);
+  }
+
+  PA_LOG(INFO) << "Deserialized " << beacon_seeds.size() << " BeaconSeeds.";
+  return beacon_seeds;
+}
+
 }  // namespace
 
 EasyUnlockServiceSignin::UserData::UserData()
     : state(EasyUnlockServiceSignin::USER_DATA_STATE_INITIAL) {
 }
 
 EasyUnlockServiceSignin::UserData::~UserData() {}
 
 EasyUnlockServiceSignin::EasyUnlockServiceSignin(Profile* profile)
     : EasyUnlockService(profile),
@@ skipping 323 matching lines @@
     return;
 
   cryptauth::RemoteDeviceList remote_devices;
   for (const auto& device : devices) {
     std::string decoded_public_key, decoded_psk, decoded_challenge;
     if (!base::Base64UrlDecode(device.public_key,
                                base::Base64UrlDecodePolicy::REQUIRE_PADDING,
                                &decoded_public_key) ||
         !base::Base64UrlDecode(device.psk,
                                base::Base64UrlDecodePolicy::REQUIRE_PADDING,
-                               &decoded_psk) ||
-        !base::Base64UrlDecode(device.challenge,
-                               base::Base64UrlDecodePolicy::REQUIRE_PADDING,
-                               &decoded_challenge)) {
-      PA_LOG(ERROR) << "Unable base64url decode stored remote device: "
-                    << device.public_key;
+                               &decoded_psk)) {
+      PA_LOG(ERROR) << "Unable to decode stored remote device:\n"
+                    << "  public_key: " << device.public_key << "\n"
+                    << "  psk: " << device.psk;
       continue;
     }
     cryptauth::RemoteDevice remote_device(
         account_id.GetUserEmail(), std::string(), decoded_public_key,
         device.bluetooth_address, decoded_psk, decoded_challenge);
+
+    if (!device.serialized_beacon_seeds.empty()) {
+      PA_LOG(INFO) << "Deserializing BeaconSeeds: "
+                   << device.serialized_beacon_seeds;
+      // TODO(tengs): Assign deserialized BeaconSeeds to the RemoteDevice.
+      DeserializeBeaconSeeds(device.serialized_beacon_seeds);
+    } else {
+      PA_LOG(WARNING) << "No BeaconSeeds were loaded.";
+    }
+
     remote_devices.push_back(remote_device);
     PA_LOG(INFO) << "Loaded Remote Device:\n"
                  << "  user id: " << remote_device.user_id << "\n"
                  << "  name: " << remote_device.name << "\n"
                  << "  public key" << device.public_key << "\n"
                  << "  bt_addr:" << remote_device.bluetooth_address;
   }
 
   SetProximityAuthDevices(account_id, remote_devices);
 }
 
 const EasyUnlockServiceSignin::UserData*
     EasyUnlockServiceSignin::FindLoadedDataForCurrentUser() const {
   if (!account_id_.is_valid())
     return nullptr;
 
   const auto it = user_data_.find(account_id_);
   if (it == user_data_.end())
     return nullptr;
   if (it->second->state != USER_DATA_STATE_LOADED)
     return nullptr;
   return it->second.get();
 }