Mac Archive Type Sniffing

chrome/utility/safe_browsing/mac/udif.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_UTILITY_SAFE_BROWSING_MAC_UDIF_H_
 #define CHROME_UTILITY_SAFE_BROWSING_MAC_UDIF_H_
 
 #include <CoreFoundation/CoreFoundation.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <sys/types.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/mac/scoped_cftyperef.h"
 #include "base/macros.h"
 
 namespace safe_browsing {
 namespace dmg {
 
 class ReadStream;
 class UDIFBlock;
 

[Robert Sesek, 2017/06/12 20:52:34]

nit: no blank line (and sort by type name between class and struct)

[mortonm, 2017/06/12 21:39:49]

Done.

+struct UDIFResourceFile;
+
 // UDIFParser parses a Universal Disk Image Format file, allowing access to the
 // name, types, and data of the partitions held within the file. There is no
 // canonical documentation for UDIF, and not all disk images use UDIF (though
 // the majority do). Note that this implementation only handles UDIF and SPARSE
 // image types, not SPARSEBUNDLE.
 //
 // No guarantees are made about the position of ReadStream when using an
 // instance of this class.
 //
 // Note that this implementation relies on the UDIF blkx table to provide
@@ skipping 28 matching lines @@
   std::string GetPartitionType(size_t part_number);
 
   // Returns the size of the partition in bytes.
   size_t GetPartitionSize(size_t part_number);
 
   // Returns a stream of the raw partition data for the given partition
   // number.
   std::unique_ptr<ReadStream> GetPartitionReadStream(size_t part_number);
 
  private:
-  // Parses the blkx plist trailer structure.
+  // Parses the trailer structure. Only actually parses data from the file the
+  // first time it is called -- after that just returns the previous result when
+  // parsing was attempted.
+  bool ParseTrailer();
+
+  // Parses the blkx plist structure.
   bool ParseBlkx();
 
   ReadStream* const stream_;  // The stream backing the UDIF image. Weak.
   std::vector<std::string> partition_names_;  // The names of all partitions.
   // All blocks in the UDIF image.
   std::vector<std::unique_ptr<const UDIFBlock>> blocks_;
   uint16_t block_size_;  // The image's block size, in bytes.
+  std::unique_ptr<UDIFResourceFile> trailer_;

[Robert Sesek, 2017/06/12 20:52:34]

These two members need comments.

[mortonm, 2017/06/12 21:39:49]

Done.

+  bool trailer_successfully_parsed_;
 
   DISALLOW_COPY_AND_ASSIGN(UDIFParser);
 };
 
 }  // namespace dmg
 }  // namespace safe_browsing
 
 #endif  // CHROME_UTILITY_SAFE_BROWSING_MAC_UDIF_H_