From d77399b82b4f13db52f1ec0e79c3bbb3f8c4e6ba Mon Sep 17 00:00:00 2001
From: Mike Auty <mike.auty@gmail.com>
Date: Mon, 30 Nov 2020 23:47:53 +0000
Subject: [PATCH] Pdbconv: Use both pefile and volatility to get the guid

---
 .../framework/symbols/windows/pdbutil.py      | 37 ++++++++++++++-----
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/volatility/framework/symbols/windows/pdbutil.py b/volatility/framework/symbols/windows/pdbutil.py
index 196cfc526..8462f4216 100644
--- a/volatility/framework/symbols/windows/pdbutil.py
+++ b/volatility/framework/symbols/windows/pdbutil.py
@@ -3,6 +3,7 @@
 #
 
 import binascii
+import io
 import json
 import logging
 import lzma
@@ -16,6 +17,7 @@ from volatility.framework import constants, interfaces
 from volatility.framework.configuration.requirements import SymbolTableRequirement
 from volatility.framework.symbols import intermed
 from volatility.framework.symbols.windows import pdbconv
+from volatility.framework.symbols.windows.extensions import pe
 
 vollog = logging.getLogger(__name__)
 
@@ -124,21 +126,36 @@ class PDBUtility:
         if mz_sig != b"MZ":
             return None
 
-        nt_header_start = ord(layer.read(offset + 0x3C, 1))
-        optional_header_size = struct.unpack('<H', layer.read(offset + nt_header_start + 0x14, 2))[0]
-        # Just enough to tell us the max size
-        pe_header = layer.read(offset, nt_header_start + 0x16 + optional_header_size)
-        pe_data = pefile.PE(data = pe_header)
-        max_size = pe_data.OPTIONAL_HEADER.SizeOfImage
+        pe_table_name = intermed.IntermediateSymbolTable.create(context,
+                                                                'pdbutility',
+                                                                "windows",
+                                                                "pe",
+                                                                class_types = pe.class_types)
+
+        dos_header = context.object(pe_table_name + constants.BANG + '_IMAGE_DOS_HEADER', offset = offset,
+                                    layer_name = layer_name)
+        mz_data = io.BytesIO()
+        for offset, data in dos_header.reconstruct():
+            mz_data.seek(offset)
+            mz_data.write(data)
+        mz_data = bytes(mz_data.getbuffer())
+
+        pe_data = pefile.PE(data = mz_data)
 
-        # Proper data
-        pe_header = layer.read(offset, max_size)
-        pe_data = pefile.PE(data = pe_header)
         if not hasattr(pe_data, 'DIRECTORY_ENTRY_DEBUG') or not len(pe_data.DIRECTORY_ENTRY_DEBUG):
             return None
 
         # Extract the data
-        debug_entry = pe_data.DIRECTORY_ENTRY_DEBUG[0].entry
+        debug_data = pe_data.DIRECTORY_ENTRY_DEBUG[0]
+
+        # We don't fix up subvalues in reconstruction
+        # This resets the PointerToRawData to the AddressOfRawData
+        pe_data.set_dword_at_offset(debug_data.struct.get_field_absolute_offset('PointerToRawData'),
+                                    debug_data.struct.AddressOfRawData)
+        debug_entry = debug_data.entry
+
+        if debug_entry is None:
+            return None
         pdb_name = debug_entry.PdbFileName.decode("utf-8").strip('\x00')
         age = debug_entry.Age
         guid = "{:x}{:x}{:x}{}".format(debug_entry.Signature_Data1, debug_entry.Signature_Data2,