1// Copyright 2013 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#include "chrome/browser/media/media_device_id_salt.h"
5
6#include "base/base64.h"
7#include "base/prefs/pref_service.h"
8#include "base/rand_util.h"
9#include "chrome/browser/profiles/profile_io_data.h"
10#include "chrome/common/pref_names.h"
11#include "content/public/browser/browser_thread.h"
12
13using content::BrowserThread;
14
15namespace {
16
17std::string CreateSalt() {
18  std::string salt;
19  base::Base64Encode(base::RandBytesAsString(16), &salt);
20  DCHECK(!salt.empty());
21  return salt;
22}
23
24}  // namespace
25
26MediaDeviceIDSalt::MediaDeviceIDSalt(PrefService* pref_service,
27                                     bool incognito) {
28  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
29
30  if (incognito) {
31    incognito_salt_ = CreateSalt();
32    return;
33  }
34
35  media_device_id_salt_.Init(prefs::kMediaDeviceIdSalt, pref_service);
36  if (media_device_id_salt_.GetValue().empty())
37    media_device_id_salt_.SetValue(CreateSalt());
38
39  media_device_id_salt_.MoveToThread(
40      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
41}
42
43MediaDeviceIDSalt::~MediaDeviceIDSalt() {
44}
45
46void MediaDeviceIDSalt::ShutdownOnUIThread() {
47  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
48  if (incognito_salt_.empty())
49    media_device_id_salt_.Destroy();
50}
51
52std::string MediaDeviceIDSalt::GetSalt() const {
53  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
54  if (incognito_salt_.size())
55    return incognito_salt_;
56  return media_device_id_salt_.GetValue();
57}
58
59void MediaDeviceIDSalt::RegisterProfilePrefs(
60    user_prefs::PrefRegistrySyncable* registry) {
61  registry->RegisterStringPref(
62      prefs::kMediaDeviceIdSalt,
63      std::string(),
64      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
65}
66
67void MediaDeviceIDSalt::Reset(PrefService* pref_service) {
68  pref_service->SetString(prefs::kMediaDeviceIdSalt,
69                          CreateSalt());
70}
71