Distinguish between user and owner passwords.

core/fpdfapi/fpdf_parser/cpdf_parser.cpp

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fpdfapi/fpdf_parser/include/cpdf_parser.h"
 
 #include <vector>
 
@@ skipping 1461 matching lines @@
   if (m_pSyntax->GetKeyword() != "trailer")
     return nullptr;
 
   std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> pObj(
       m_pSyntax->GetObject(m_pDocument, 0, 0, true));
   if (!ToDictionary(pObj.get()))
     return nullptr;
   return pObj.release()->AsDictionary();
 }
 
-uint32_t CPDF_Parser::GetPermissions(FX_BOOL bCheckRevision) {
+uint32_t CPDF_Parser::GetPermissions() const {
   if (!m_pSecurityHandler)
-    return (uint32_t)-1;
+    return 0xFFFFFFFF;
 
   uint32_t dwPermission = m_pSecurityHandler->GetPermissions();
   if (m_pEncryptDict && m_pEncryptDict->GetStringBy("Filter") == "Standard") {
+    // See PDF Reference 1.7, page 123, table 3.20.
     dwPermission &= 0xFFFFFFFC;
     dwPermission |= 0xFFFFF0C0;
-    if (bCheckRevision && m_pEncryptDict->GetIntegerBy("R") == 2)
-      dwPermission &= 0xFFFFF0FF;
   }
   return dwPermission;
 }
 
 FX_BOOL CPDF_Parser::IsLinearizedFile(IFX_FileRead* pFileAccess,
                                       uint32_t offset) {
   m_pSyntax->InitParser(pFileAccess, offset);
   m_pSyntax->RestorePos(m_pSyntax->m_HeaderOffset + 9);
 
   FX_FILESIZE SavedPos = m_pSyntax->SavePos();
@@ skipping 168 matching lines @@
   if (!LoadLinearizedAllCrossRefV4(m_LastXRefOffset, m_dwXrefStartObjNum) &&
       !LoadLinearizedAllCrossRefV5(m_LastXRefOffset)) {
     m_LastXRefOffset = 0;
     m_pSyntax->m_MetadataObjnum = dwSaveMetadataObjnum;
     return FORMAT_ERROR;
   }
 
   m_pSyntax->m_MetadataObjnum = dwSaveMetadataObjnum;
   return SUCCESS;
 }