extensions/browser/content_hash_reader.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_CONTENT_HASH_READER_H_
   6 #define EXTENSIONS_BROWSER_CONTENT_HASH_READER_H_
   7
   8 #include <string>
   9
  10 #include "base/files/file_path.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/version.h"
  14 #include "extensions/browser/content_verifier_delegate.h"
  15
  16 namespace extensions {
  17
  18 // This class creates an object that will read expected hashes that may have
  19 // been fetched/calculated by the ContentHashFetcher, and vends them out for
  20 // use in ContentVerifyJob's.
  21 class ContentHashReader : public base::RefCountedThreadSafe<ContentHashReader> {
  22  public:
  23   // Create one of these to get expected hashes for the file at |relative_path|
  24   // within an extension.
  25   ContentHashReader(const std::string& extension_id,
  26                     const base::Version& extension_version,
  27                     const base::FilePath& extension_root,
  28                     const base::FilePath& relative_path,
  29                     const ContentVerifierKey& key);
  30
  31   const std::string& extension_id() const { return extension_id_; }
  32   const base::FilePath& relative_path() const { return relative_path_; }
  33
  34   // This should be called to initialize this object (reads the expected hashes
  35   // from storage, etc.). Must be called on a thread that is allowed to do file
  36   // I/O. Returns a boolean indicating success/failure. On failure, this object
  37   // should likely be discarded.
  38   bool Init();
  39
  40   // Return the number of blocks and block size, respectively. Only valid after
  41   // calling Init().
  42   int block_count() const;
  43   int block_size() const;
  44
  45   // Returns a pointer to the expected sha256 hash value for the block at the
  46   // given index. Only valid after calling Init().
  47   bool GetHashForBlock(int block_index, const std::string** result) const;
  48
  49  private:
  50   friend class base::RefCountedThreadSafe<ContentHashReader>;
  51   virtual ~ContentHashReader();
  52
  53   bool ReadHashes(const base::FilePath& hashes_file);
  54
  55   std::string extension_id_;
  56   base::Version extension_version_;
  57   base::FilePath extension_root_;
  58   base::FilePath relative_path_;
  59   ContentVerifierKey key_;
  60
  61   DISALLOW_COPY_AND_ASSIGN(ContentHashReader);
  62 };
  63
  64 }  // namespace extensions
  65
  66 #endif  // EXTENSIONS_BROWSER_CONTENT_HASH_READER_H_