Add fuzzer test for preg_parser

components/policy/core/common/preg_parser.h

 // Copyright (c) 2013 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.
 
 // This file provides a parser for PReg files which are used for storing group
 // policy settings in the file system. The file format is documented here:
 //
 // http://msdn.microsoft.com/en-us/library/windows/desktop/aa374407(v=vs.85).aspx
 
 #ifndef COMPONENTS_POLICY_CORE_COMMON_PREG_PARSER_H_
 #define COMPONENTS_POLICY_CORE_COMMON_PREG_PARSER_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/strings/string16.h"
+#include "components/policy/core/common/policy_load_status.h"
 #include "components/policy/policy_export.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace policy {
 
-class PolicyLoadStatusSample;
 class RegistryDict;
 
 namespace preg_parser {
 
 // The magic header in PReg files: ASCII "PReg" + version (0x0001).
 POLICY_EXPORT extern const char kPRegFileHeader[8];
 
 // Reads the PReg file at |file_path| and writes the registry data to |dict|.
-// |root| specifies the registry subtree the caller is interested in,
-// everything else gets ignored.
+// |root| specifies the registry subtree the caller is interested in, everything
+// else gets ignored.
 POLICY_EXPORT bool ReadFile(const base::FilePath& file_path,
                             const base::string16& root,
                             RegistryDict* dict,
-                            PolicyLoadStatusSample* status);
+                            PolicyLoadStatusSample* status_sample);
+
+// Reads the PReg data at |data| of length |data_size| and writes the registry
+// data to |dict|. |root| specifies the registry subtree the caller is
+// interested in, everything else gets ignored. |debug_name| is printed out
+// along with error messages. Returns false and sets |status| on error.
+POLICY_EXPORT bool ReadData(const uint8_t* data,

[Thiemo Nagel, 2017/04/07 09:39:57]

I don't think it is fair to export an interface with raw pointers just to suit
libfuzzer.

[Thiemo Nagel, 2017/04/07 09:55:41]

As discussed offline, imho it would be fair to add "Internal" to the name and
add a comment that it must only be used by ReadFile() or for testing.

[ljusten (tachyonic), 2017/04/10 10:22:51]

As discussed offline, I'll add Internal to the name and a comment.

+                            size_t data_size,
+                            const base::string16& root,
+                            RegistryDict* dict,
+                            PolicyLoadStatus* status,
+                            const std::string& debug_name);
 
 }  // namespace preg_parser
 }  // namespace policy
 
 #endif  // COMPONENTS_POLICY_CORE_COMMON_PREG_PARSER_H_