1// Copyright (c) 2012 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 CHROMEOS_CRYPTOHOME_SYSTEM_SALT_GETTER_H_
6#define CHROMEOS_CRYPTOHOME_SYSTEM_SALT_GETTER_H_
7
8#include <string>
9#include <vector>
10
11#include "base/basictypes.h"
12#include "base/callback_forward.h"
13#include "base/memory/weak_ptr.h"
14#include "chromeos/chromeos_export.h"
15#include "chromeos/dbus/dbus_method_call_status.h"
16
17namespace chromeos {
18
19// This class is used to get the system salt from cryptohome and cache it.
20class CHROMEOS_EXPORT SystemSaltGetter {
21 public:
22  typedef base::Callback<void(const std::string& system_salt)>
23      GetSystemSaltCallback;
24
25  // Manage an explicitly initialized global instance.
26  static void Initialize();
27  static bool IsInitialized();
28  static void Shutdown();
29  static SystemSaltGetter* Get();
30
31  // Converts |salt| to a hex encoded string.
32  static std::string ConvertRawSaltToHexString(const std::vector<uint8>& salt);
33
34  // Returns system hash in hex encoded ascii format. Note: this may return
35  // an empty string (e.g. errors in D-Bus layer)
36  void GetSystemSalt(const GetSystemSaltCallback& callback);
37
38 protected:
39  SystemSaltGetter();
40  ~SystemSaltGetter();
41
42 private:
43  // Used to implement GetSystemSalt().
44  void DidWaitForServiceToBeAvailable(const GetSystemSaltCallback& callback,
45                                      bool service_is_available);
46  void DidGetSystemSalt(const GetSystemSaltCallback& callback,
47                        DBusMethodCallStatus call_status,
48                        const std::vector<uint8>& system_salt);
49
50  std::string system_salt_;
51
52  base::WeakPtrFactory<SystemSaltGetter> weak_ptr_factory_;
53
54  DISALLOW_COPY_AND_ASSIGN(SystemSaltGetter);
55};
56
57}  // namespace chromeos
58
59#endif  // CHROMEOS_CRYPTOHOME_SYSTEM_SALT_GETTER_H_
60