Use a stable device-user identifier for CryptAuth enrollments.

chrome/browser/signin/easy_unlock_service.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.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/guid.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/component_loader.h"
@@ skipping 214 matching lines @@
       new base::DictionaryValue(),
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterBooleanPref(
       prefs::kEasyUnlockProximityRequired,
       false,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 }
 
 // static
 void EasyUnlockService::RegisterPrefs(PrefRegistrySimple* registry) {
+  registry->RegisterStringPref(prefs::kEasyUnlockDeviceId, std::string());
+  registry->RegisterDictionaryPref(prefs::kEasyUnlockHardlockState);
   registry->RegisterDictionaryPref(prefs::kEasyUnlockLocalStateUserPrefs);
-  registry->RegisterDictionaryPref(prefs::kEasyUnlockHardlockState);
 #if defined(OS_CHROMEOS)
   EasyUnlockTpmKeyManager::RegisterLocalStatePrefs(registry);
 #endif
 }
 
 // static
 void EasyUnlockService::ResetLocalStateForUser(const std::string& user_id) {
   DCHECK(!user_id.empty());
 
   PrefService* local_state = GetLocalState();
@@ skipping 28 matching lines @@
                                                               &user_prefs_dict))
     return user_settings;
 
   user_prefs_dict->GetBooleanWithoutPathExpansion(
       prefs::kEasyUnlockProximityRequired,
       &user_settings.require_close_proximity);
 
   return user_settings;
 }
 
+// static
+std::string EasyUnlockService::GetDeviceId() {
+  PrefService* local_state = GetLocalState();
+  if (!local_state)
+    return std::string();
+
+  std::string device_id =
+      local_state->GetString(prefs::kEasyUnlockDeviceId);
+  if (device_id.empty()) {
+    device_id = base::GenerateGUID();
+    local_state->SetString(prefs::kEasyUnlockDeviceId, device_id);
+  }
+  return device_id;
+}
+
 bool EasyUnlockService::IsAllowed() {
   if (shut_down_)
     return false;
 
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           proximity_auth::switches::kDisableEasyUnlock)) {
     return false;
   }
 
   if (!IsAllowedInternal())
@@ skipping 459 matching lines @@
 
   // TODO(tbarzic): Set check_private_key only if previous sign-in attempt
   // failed.
   EasyUnlockTpmKeyManagerFactory::GetInstance()->Get(profile_)
       ->PrepareTpmKey(true /* check_private_key */,
                       base::Closure());
 #endif  // defined(OS_CHROMEOS)
 
   tpm_key_checked_ = true;
 }