[NtRegistry] Ensure REG_SZ and REG_MULTI_SZ are null terminated.

chrome_elf/nt_registry/nt_registry.h

 // Copyright 2016 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 API is a usability layer for direct registry access via NTDLL.
 // It allows for "advapi32-free" registry access, which is especially
 // useful for accessing registy from DllMain (holding loader lock),
 // or if a dependency on/linkage of ADVAPI32.dll is not desired.
 
 // The implementation of this API should only use ntdll and kernel32 system
@@ skipping 74 matching lines @@
 // Close a registry key handle that was opened with CreateRegKey or OpenRegKey.
 void CloseRegKey(HANDLE key);
 
 //------------------------------------------------------------------------------
 // Getter functions
 //------------------------------------------------------------------------------
 
 // Main function to query a registry value.
 // - Key handle should have been opened with CreateRegKey or OpenRegKey.
 // - Types defined in winnt.h.  E.g.: REG_DWORD, REG_SZ.
-// - Caller is responsible for calling "delete[] *out_buffer" (on success).
 bool QueryRegKeyValue(HANDLE key,
                       const wchar_t* value_name,
                       ULONG* out_type,
-                      BYTE** out_buffer,
-                      DWORD* out_size);
+                      std::vector<BYTE>* out_buffer);
 
 // Query DWORD value.
 // - WRAPPER: Function works with DWORD data type.
 // - Key handle should have been opened with CreateRegKey or OpenRegKey.
 // - Handle will be left open.  Caller must still call CloseRegKey when done.
 bool QueryRegValueDWORD(HANDLE key,
                         const wchar_t* value_name,
                         DWORD* out_dword);
 
 // Query DWORD value.
 // - WRAPPER: Function opens and closes the target key for caller, and works
 // with DWORD data type.
 // - Use |wow64_override| to force redirection behaviour, or pass nt::NONE.
 bool QueryRegValueDWORD(ROOT_KEY root,
                         WOW64_OVERRIDE wow64_override,
                         const wchar_t* key_path,
                         const wchar_t* value_name,
                         DWORD* out_dword);
 
 // Query SZ (string) value.
-// - WRAPPER: Function works with SZ data type.
+// - WRAPPER: Function works with SZ or EXPAND_SZ data type.
 // - Key handle should have been opened with CreateRegKey or OpenRegKey.
 // - Handle will be left open.  Caller must still call CloseRegKey when done.
+// - Note: this function only returns the string up to the first end-of-string.
+//   Any string packed with embedded nulls can be accessed via the raw
+//   QueryRegKeyValue function.
 bool QueryRegValueSZ(HANDLE key,
                      const wchar_t* value_name,
                      std::wstring* out_sz);
 
 // Query SZ (string) value.
 // - WRAPPER: Function opens and closes the target key for caller, and works
-// with SZ data type.
+// with SZ or EXPAND_SZ data type.
 // - Use |wow64_override| to force redirection behaviour, or pass nt::NONE.
+// - Note: this function only returns the string up to the first end-of-string.
+//   Any string packed with embedded nulls can be accessed via the raw
+//   QueryRegKeyValue function.
 bool QueryRegValueSZ(ROOT_KEY root,
                      WOW64_OVERRIDE wow64_override,
                      const wchar_t* key_path,
                      const wchar_t* value_name,
                      std::wstring* out_sz);
 
 // Query MULTI_SZ (multiple strings) value.
 // - WRAPPER: Function works with MULTI_SZ data type.
 // - Key handle should have been opened with CreateRegKey or OpenRegKey.
 // - Handle will be left open.  Caller must still call CloseRegKey when done.
@@ skipping 88 matching lines @@
 
 // Setter function for test suites that use reg redirection.
 bool SetTestingOverride(ROOT_KEY root, const std::wstring& new_path);
 
 // Getter function for test suites that use reg redirection.
 std::wstring GetTestingOverride(ROOT_KEY root);
 
 };  // namespace nt
 
 #endif  // CHROME_ELF_NT_REGISTRY_NT_REGISTRY_H_