pref_hash_calculator.h revision 5f1c94371a64b3196d4be9466099bb892df9b88e 
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
5#ifndef CHROME_BROWSER_PREFS_PREF_HASH_CALCULATOR_H_
6#define CHROME_BROWSER_PREFS_PREF_HASH_CALCULATOR_H_
7
8#include <string>
9
10#include "base/basictypes.h"
11
12namespace base {
13class Value;
14}  // namespace base
15
16// Calculates and validates preference value hashes.
17class PrefHashCalculator {
18 public:
19  enum ValidationResult {
20    INVALID,
21    VALID,
22    // Valid under a deprecated but as secure algorithm.
23    VALID_SECURE_LEGACY,
24  };
25
26  // Constructs a PrefHashCalculator using |seed| and |device_id|. The same
27  // parameters must be used in order to successfully validate generated hashes.
28  // |device_id| may be empty.
29  PrefHashCalculator(const std::string& seed, const std::string& device_id);
30
31  ~PrefHashCalculator();
32
33  // Calculates a hash value for the supplied preference |path| and |value|.
34  // |value| may be null if the preference has no value.
35  std::string Calculate(const std::string& path, const base::Value* value)
36      const;
37
38  // Validates the provided preference hash using current and legacy hashing
39  // algorithms.
40  ValidationResult Validate(const std::string& path,
41                            const base::Value* value,
42                            const std::string& hash) const;
43
44 private:
45  const std::string seed_;
46  const std::string device_id_;
47  const std::string legacy_device_id_;
48
49  DISALLOW_COPY_AND_ASSIGN(PrefHashCalculator);
50};
51
52#endif  // CHROME_BROWSER_PREFS_PREF_HASH_CALCULATOR_H_
53