1 // Copyright 2018 The PDFium Authors 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com 6 7 #include "fpdfsdk/cpdfsdk_customaccess.h" 8 9 #include "core/fxcrt/fx_safe_types.h" 10 #include "core/fxcrt/numerics/safe_conversions.h" 11 CPDFSDK_CustomAccess(FPDF_FILEACCESS * pFileAccess)12CPDFSDK_CustomAccess::CPDFSDK_CustomAccess(FPDF_FILEACCESS* pFileAccess) 13 : m_FileAccess(*pFileAccess) {} 14 15 CPDFSDK_CustomAccess::~CPDFSDK_CustomAccess() = default; 16 GetSize()17FX_FILESIZE CPDFSDK_CustomAccess::GetSize() { 18 return m_FileAccess.m_FileLen; 19 } 20 ReadBlockAtOffset(pdfium::span<uint8_t> buffer,FX_FILESIZE offset)21bool CPDFSDK_CustomAccess::ReadBlockAtOffset(pdfium::span<uint8_t> buffer, 22 FX_FILESIZE offset) { 23 if (buffer.empty() || offset < 0) 24 return false; 25 26 if (!pdfium::IsValueInRangeForNumericType<FX_FILESIZE>(buffer.size())) { 27 return false; 28 } 29 30 FX_SAFE_FILESIZE new_pos = buffer.size(); 31 new_pos += offset; 32 return new_pos.IsValid() && new_pos.ValueOrDie() <= GetSize() && 33 m_FileAccess.m_GetBlock( 34 m_FileAccess.m_Param, pdfium::checked_cast<unsigned long>(offset), 35 buffer.data(), pdfium::checked_cast<unsigned long>(buffer.size())); 36 } 37