extensions/browser/computed_hashes.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 EXTENSIONS_BROWSER_COMPUTED_HASHES_H_
   6 #define EXTENSIONS_BROWSER_COMPUTED_HASHES_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/memory/scoped_ptr.h"
  13
  14 namespace base {
  15 class FilePath;
  16 class ListValue;
  17 }
  18
  19 namespace extensions {
  20
  21 // A pair of classes for serialization of a set of SHA256 block hashes computed
  22 // over the files inside an extension.
  23 class ComputedHashes {
  24  public:
  25   class Reader {
  26    public:
  27     Reader();
  28     ~Reader();
  29     bool InitFromFile(const base::FilePath& path);
  30
  31     // The block size and hashes for |relative_path| will be copied into the
  32     // out parameters.
  33     bool GetHashes(const base::FilePath& relative_path,
  34                    int* block_size,
  35                    std::vector<std::string>* hashes);
  36
  37    private:
  38     typedef std::pair<int, std::vector<std::string> > HashInfo;
  39
  40     // This maps a relative path to a pair of (block size, hashes)
  41     std::map<base::FilePath, HashInfo> data_;
  42   };
  43
  44   class Writer {
  45    public:
  46     Writer();
  47     ~Writer();
  48
  49     // Adds hashes for |relative_path|. Should not be called more than once
  50     // for a given |relative_path|.
  51     void AddHashes(const base::FilePath& relative_path,
  52                    int block_size,
  53                    const std::vector<std::string>& hashes);
  54
  55     bool WriteToFile(const base::FilePath& path);
  56
  57    private:
  58     // Each element of this list contains the path and block hashes for one
  59     // file.
  60     scoped_ptr<base::ListValue> file_list_;
  61   };
  62
  63   // Computes the SHA256 hash of each |block_size| chunk in |contents|, placing
  64   // the results into |hashes|.
  65   static void ComputeHashesForContent(const std::string& contents,
  66                                       size_t block_size,
  67                                       std::vector<std::string>* hashes);
  68 };
  69
  70 }  // namespace extensions
  71
  72 #endif  // EXTENSIONS_BROWSER_COMPUTED_HASHES_H_