components/metrics/cloned_install_detector.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_METRICS_CLONED_INSTALL_DETECTOR_H_
   6 #define COMPONENTS_METRICS_CLONED_INSTALL_DETECTOR_H_
   7
   8 #include "base/gtest_prod_util.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/weak_ptr.h"
  11
  12 class PrefRegistrySimple;
  13 class PrefService;
  14
  15 namespace base {
  16 class SingleThreadTaskRunner;
  17 }
  18
  19 namespace metrics {
  20
  21 class MachineIdProvider;
  22
  23 // A class for detecting if an install is cloned. It does this by detecting
  24 // when the hardware running Chrome changes.
  25 class ClonedInstallDetector {
  26  public:
  27   explicit ClonedInstallDetector(MachineIdProvider* raw_id_provider);
  28   virtual ~ClonedInstallDetector();
  29
  30   // Posts a task to |task_runner| to generate a machine ID and store it to a
  31   // local state pref. If the newly generated ID is different than the
  32   // previously stored one, then the install is considered cloned. The ID is a
  33   // 24-bit value based off of machine characteristics. This value should never
  34   // be sent over the network.
  35   // TODO(jwd): Implement change detection.
  36   void CheckForClonedInstall(
  37       PrefService* local_state,
  38       scoped_refptr<base::SingleThreadTaskRunner> task_runner);
  39
  40   static void RegisterPrefs(PrefRegistrySimple* registry);
  41
  42  private:
  43   FRIEND_TEST_ALL_PREFIXES(ClonedInstallDetectorTest, SaveId);
  44   FRIEND_TEST_ALL_PREFIXES(ClonedInstallDetectorTest, DetectClone);
  45
  46   // Converts raw_id into a 24-bit hash and stores the hash in |local_state|.
  47   // |raw_id| is not a const ref because it's passed from a cross-thread post
  48   // task.
  49   void SaveMachineId(PrefService* local_state, std::string raw_id);
  50
  51   scoped_refptr<MachineIdProvider> raw_id_provider_;
  52   base::WeakPtrFactory<ClonedInstallDetector> weak_ptr_factory_;
  53
  54   DISALLOW_COPY_AND_ASSIGN(ClonedInstallDetector);
  55 };
  56
  57 }  // namespace metrics
  58
  59 #endif  // COMPONENTS_METRICS_CLONED_INSTALL_DETECTOR_H_