diff options
Diffstat (limited to 'core/src/fpdfapi/fpdf_parser/cpdf_parser.cpp')
| -rw-r--r-- | core/src/fpdfapi/fpdf_parser/cpdf_parser.cpp | 1643 |
1 files changed, 1643 insertions, 0 deletions
diff --git a/core/src/fpdfapi/fpdf_parser/cpdf_parser.cpp b/core/src/fpdfapi/fpdf_parser/cpdf_parser.cpp new file mode 100644 index 0000000000..1871467458 --- /dev/null +++ b/core/src/fpdfapi/fpdf_parser/cpdf_parser.cpp @@ -0,0 +1,1643 @@ +// 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/include/fpdfapi/cpdf_parser.h" + +#include "core/include/fpdfapi/cpdf_document.h" +#include "core/include/fpdfapi/fpdf_parser.h" +#include "core/include/fxcrt/fx_ext.h" +#include "core/include/fxcrt/fx_safe_types.h" +#include "core/src/fpdfapi/fpdf_parser/cpdf_syntax_parser.h" +#include "core/src/fpdfapi/fpdf_parser/fpdf_parser_utility.h" +#include "third_party/base/stl_util.h" + +namespace { + +// A limit on the size of the xref table. Theoretical limits are higher, but +// this may be large enough in practice. +const int32_t kMaxXRefSize = 1048576; + +// A limit on the maximum object number in the xref table. Theoretical limits +// are higher, but this may be large enough in practice. +const FX_DWORD kMaxObjectNumber = 1048576; + +FX_DWORD GetVarInt(const uint8_t* p, int32_t n) { + FX_DWORD result = 0; + for (int32_t i = 0; i < n; ++i) + result = result * 256 + p[i]; + return result; +} + +int32_t GetStreamNCount(CPDF_StreamAcc* pObjStream) { + return pObjStream->GetDict()->GetIntegerBy("N"); +} + +int32_t GetStreamFirst(CPDF_StreamAcc* pObjStream) { + return pObjStream->GetDict()->GetIntegerBy("First"); +} + +} // namespace + +CPDF_Parser::CPDF_Parser() + : m_pDocument(nullptr), + m_bOwnFileRead(true), + m_FileVersion(0), + m_pTrailer(nullptr), + m_pEncryptDict(nullptr), + m_pLinearized(nullptr), + m_dwFirstPageNo(0), + m_dwXrefStartObjNum(0) { + m_pSyntax.reset(new CPDF_SyntaxParser); +} + +CPDF_Parser::~CPDF_Parser() { + CloseParser(); +} + +FX_DWORD CPDF_Parser::GetLastObjNum() const { + return m_ObjectInfo.empty() ? 0 : m_ObjectInfo.rbegin()->first; +} + +bool CPDF_Parser::IsValidObjectNumber(FX_DWORD objnum) const { + return !m_ObjectInfo.empty() && objnum <= m_ObjectInfo.rbegin()->first; +} + +FX_FILESIZE CPDF_Parser::GetObjectPositionOrZero(FX_DWORD objnum) const { + auto it = m_ObjectInfo.find(objnum); + return it != m_ObjectInfo.end() ? it->second.pos : 0; +} + +uint8_t CPDF_Parser::GetObjectType(FX_DWORD objnum) const { + ASSERT(IsValidObjectNumber(objnum)); + auto it = m_ObjectInfo.find(objnum); + return it != m_ObjectInfo.end() ? it->second.type : 0; +} + +uint16_t CPDF_Parser::GetObjectGenNum(FX_DWORD objnum) const { + ASSERT(IsValidObjectNumber(objnum)); + auto it = m_ObjectInfo.find(objnum); + return it != m_ObjectInfo.end() ? it->second.gennum : 0; +} + +bool CPDF_Parser::IsObjectFreeOrNull(FX_DWORD objnum) const { + uint8_t type = GetObjectType(objnum); + return type == 0 || type == 255; +} + +void CPDF_Parser::SetEncryptDictionary(CPDF_Dictionary* pDict) { + m_pEncryptDict = pDict; +} + +CPDF_CryptoHandler* CPDF_Parser::GetCryptoHandler() { + return m_pSyntax->m_pCryptoHandler.get(); +} + +IFX_FileRead* CPDF_Parser::GetFileAccess() const { + return m_pSyntax->m_pFileAccess; +} + +void CPDF_Parser::ShrinkObjectMap(FX_DWORD objnum) { + if (objnum == 0) { + m_ObjectInfo.clear(); + return; + } + + auto it = m_ObjectInfo.lower_bound(objnum); + while (it != m_ObjectInfo.end()) { + auto saved_it = it++; + m_ObjectInfo.erase(saved_it); + } + + if (!pdfium::ContainsKey(m_ObjectInfo, objnum - 1)) + m_ObjectInfo[objnum - 1].pos = 0; +} + +void CPDF_Parser::CloseParser() { + m_bVersionUpdated = FALSE; + delete m_pDocument; + m_pDocument = nullptr; + + if (m_pTrailer) { + m_pTrailer->Release(); + m_pTrailer = nullptr; + } + ReleaseEncryptHandler(); + SetEncryptDictionary(nullptr); + + if (m_bOwnFileRead && m_pSyntax->m_pFileAccess) { + m_pSyntax->m_pFileAccess->Release(); + m_pSyntax->m_pFileAccess = nullptr; + } + + m_ObjectStreamMap.clear(); + m_ObjCache.clear(); + m_SortedOffset.clear(); + m_ObjectInfo.clear(); + + int32_t iLen = m_Trailers.GetSize(); + for (int32_t i = 0; i < iLen; ++i) { + if (CPDF_Dictionary* trailer = m_Trailers.GetAt(i)) + trailer->Release(); + } + m_Trailers.RemoveAll(); + + if (m_pLinearized) { + m_pLinearized->Release(); + m_pLinearized = nullptr; + } +} + +CPDF_Parser::Error CPDF_Parser::StartParse(IFX_FileRead* pFileAccess) { + CloseParser(); + + m_bXRefStream = FALSE; + m_LastXRefOffset = 0; + m_bOwnFileRead = true; + + int32_t offset = GetHeaderOffset(pFileAccess); + if (offset == -1) { + if (pFileAccess) + pFileAccess->Release(); + return FORMAT_ERROR; + } + m_pSyntax->InitParser(pFileAccess, offset); + + uint8_t ch; + if (!m_pSyntax->GetCharAt(5, ch)) + return FORMAT_ERROR; + if (std::isdigit(ch)) + m_FileVersion = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch)) * 10; + + if (!m_pSyntax->GetCharAt(7, ch)) + return FORMAT_ERROR; + if (std::isdigit(ch)) + m_FileVersion += FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch)); + + if (m_pSyntax->m_FileLen < m_pSyntax->m_HeaderOffset + 9) + return FORMAT_ERROR; + + m_pSyntax->RestorePos(m_pSyntax->m_FileLen - m_pSyntax->m_HeaderOffset - 9); + m_pDocument = new CPDF_Document(this); + + FX_BOOL bXRefRebuilt = FALSE; + if (m_pSyntax->SearchWord("startxref", TRUE, FALSE, 4096)) { + m_SortedOffset.insert(m_pSyntax->SavePos()); + m_pSyntax->GetKeyword(); + + bool bNumber; + CFX_ByteString xrefpos_str = m_pSyntax->GetNextWord(&bNumber); + if (!bNumber) + return FORMAT_ERROR; + + m_LastXRefOffset = (FX_FILESIZE)FXSYS_atoi64(xrefpos_str); + if (!LoadAllCrossRefV4(m_LastXRefOffset) && + !LoadAllCrossRefV5(m_LastXRefOffset)) { + if (!RebuildCrossRef()) + return FORMAT_ERROR; + + bXRefRebuilt = TRUE; + m_LastXRefOffset = 0; + } + } else { + if (!RebuildCrossRef()) + return FORMAT_ERROR; + + bXRefRebuilt = TRUE; + } + Error eRet = SetEncryptHandler(); + if (eRet != SUCCESS) + return eRet; + + m_pDocument->LoadDoc(); + if (!m_pDocument->GetRoot() || m_pDocument->GetPageCount() == 0) { + if (bXRefRebuilt) + return FORMAT_ERROR; + + ReleaseEncryptHandler(); + if (!RebuildCrossRef()) + return FORMAT_ERROR; + + eRet = SetEncryptHandler(); + if (eRet != SUCCESS) + return eRet; + + m_pDocument->LoadDoc(); + if (!m_pDocument->GetRoot()) + return FORMAT_ERROR; + } + if (GetRootObjNum() == 0) { + ReleaseEncryptHandler(); + if (!RebuildCrossRef() || GetRootObjNum() == 0) + return FORMAT_ERROR; + + eRet = SetEncryptHandler(); + if (eRet != SUCCESS) + return eRet; + } + if (m_pSecurityHandler && !m_pSecurityHandler->IsMetadataEncrypted()) { + CPDF_Reference* pMetadata = + ToReference(m_pDocument->GetRoot()->GetElement("Metadata")); + if (pMetadata) + m_pSyntax->m_MetadataObjnum = pMetadata->GetRefObjNum(); + } + return SUCCESS; +} +CPDF_Parser::Error CPDF_Parser::SetEncryptHandler() { + ReleaseEncryptHandler(); + SetEncryptDictionary(nullptr); + + if (!m_pTrailer) + return FORMAT_ERROR; + + CPDF_Object* pEncryptObj = m_pTrailer->GetElement("Encrypt"); + if (pEncryptObj) { + if (CPDF_Dictionary* pEncryptDict = pEncryptObj->AsDictionary()) { + SetEncryptDictionary(pEncryptDict); + } else if (CPDF_Reference* pRef = pEncryptObj->AsReference()) { + pEncryptObj = m_pDocument->GetIndirectObject(pRef->GetRefObjNum()); + if (pEncryptObj) + SetEncryptDictionary(pEncryptObj->GetDict()); + } + } + + if (m_pEncryptDict) { + CFX_ByteString filter = m_pEncryptDict->GetStringBy("Filter"); + std::unique_ptr<IPDF_SecurityHandler> pSecurityHandler; + Error err = HANDLER_ERROR; + if (filter == "Standard") { + pSecurityHandler.reset(new CPDF_StandardSecurityHandler); + err = PASSWORD_ERROR; + } + if (!pSecurityHandler) + return HANDLER_ERROR; + + if (!pSecurityHandler->OnInit(this, m_pEncryptDict)) + return err; + + m_pSecurityHandler = std::move(pSecurityHandler); + std::unique_ptr<CPDF_CryptoHandler> pCryptoHandler( + m_pSecurityHandler->CreateCryptoHandler()); + if (!pCryptoHandler->Init(m_pEncryptDict, m_pSecurityHandler.get())) + return HANDLER_ERROR; + m_pSyntax->SetEncrypt(std::move(pCryptoHandler)); + } + return SUCCESS; +} + +void CPDF_Parser::ReleaseEncryptHandler() { + m_pSyntax->m_pCryptoHandler.reset(); + m_pSecurityHandler.reset(); +} + +FX_FILESIZE CPDF_Parser::GetObjectOffset(FX_DWORD objnum) const { + if (!IsValidObjectNumber(objnum)) + return 0; + + if (GetObjectType(objnum) == 1) + return GetObjectPositionOrZero(objnum); + + if (GetObjectType(objnum) == 2) { + FX_FILESIZE pos = GetObjectPositionOrZero(objnum); + return GetObjectPositionOrZero(pos); + } + return 0; +} + +FX_BOOL CPDF_Parser::LoadAllCrossRefV4(FX_FILESIZE xrefpos) { + if (!LoadCrossRefV4(xrefpos, 0, TRUE)) + return FALSE; + + m_pTrailer = LoadTrailerV4(); + if (!m_pTrailer) + return FALSE; + + int32_t xrefsize = GetDirectInteger(m_pTrailer, "Size"); + if (xrefsize > 0 && xrefsize <= kMaxXRefSize) + ShrinkObjectMap(xrefsize); + + std::vector<FX_FILESIZE> CrossRefList; + std::vector<FX_FILESIZE> XRefStreamList; + std::set<FX_FILESIZE> seen_xrefpos; + + CrossRefList.push_back(xrefpos); + XRefStreamList.push_back(GetDirectInteger(m_pTrailer, "XRefStm")); + seen_xrefpos.insert(xrefpos); + + // When |m_pTrailer| doesn't have Prev entry or Prev entry value is not + // numerical, GetDirectInteger() returns 0. Loading will end. + xrefpos = GetDirectInteger(m_pTrailer, "Prev"); + while (xrefpos) { + // Check for circular references. + if (pdfium::ContainsKey(seen_xrefpos, xrefpos)) + return FALSE; + + seen_xrefpos.insert(xrefpos); + + // SLOW ... + CrossRefList.insert(CrossRefList.begin(), xrefpos); + LoadCrossRefV4(xrefpos, 0, TRUE); + + std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict( + LoadTrailerV4()); + if (!pDict) + return FALSE; + + xrefpos = GetDirectInteger(pDict.get(), "Prev"); + + // SLOW ... + XRefStreamList.insert(XRefStreamList.begin(), + pDict->GetIntegerBy("XRefStm")); + m_Trailers.Add(pDict.release()); + } + + for (size_t i = 0; i < CrossRefList.size(); ++i) { + if (!LoadCrossRefV4(CrossRefList[i], XRefStreamList[i], FALSE)) + return FALSE; + } + return TRUE; +} + +FX_BOOL CPDF_Parser::LoadLinearizedAllCrossRefV4(FX_FILESIZE xrefpos, + FX_DWORD dwObjCount) { + if (!LoadLinearizedCrossRefV4(xrefpos, dwObjCount)) + return FALSE; + + m_pTrailer = LoadTrailerV4(); + if (!m_pTrailer) + return FALSE; + + int32_t xrefsize = GetDirectInteger(m_pTrailer, "Size"); + if (xrefsize == 0) + return FALSE; + + std::vector<FX_FILESIZE> CrossRefList; + std::vector<FX_FILESIZE> XRefStreamList; + std::set<FX_FILESIZE> seen_xrefpos; + + CrossRefList.push_back(xrefpos); + XRefStreamList.push_back(GetDirectInteger(m_pTrailer, "XRefStm")); + seen_xrefpos.insert(xrefpos); + + xrefpos = GetDirectInteger(m_pTrailer, "Prev"); + while (xrefpos) { + // Check for circular references. + if (pdfium::ContainsKey(seen_xrefpos, xrefpos)) + return FALSE; + + seen_xrefpos.insert(xrefpos); + + // SLOW ... + CrossRefList.insert(CrossRefList.begin(), xrefpos); + LoadCrossRefV4(xrefpos, 0, TRUE); + + std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict( + LoadTrailerV4()); + if (!pDict) + return FALSE; + + xrefpos = GetDirectInteger(pDict.get(), "Prev"); + + // SLOW ... + XRefStreamList.insert(XRefStreamList.begin(), + pDict->GetIntegerBy("XRefStm")); + m_Trailers.Add(pDict.release()); + } + + for (size_t i = 1; i < CrossRefList.size(); ++i) { + if (!LoadCrossRefV4(CrossRefList[i], XRefStreamList[i], FALSE)) + return FALSE; + } + return TRUE; +} + +FX_BOOL CPDF_Parser::LoadLinearizedCrossRefV4(FX_FILESIZE pos, + FX_DWORD dwObjCount) { + FX_FILESIZE dwStartPos = pos - m_pSyntax->m_HeaderOffset; + + m_pSyntax->RestorePos(dwStartPos); + m_SortedOffset.insert(pos); + + FX_DWORD start_objnum = 0; + FX_DWORD count = dwObjCount; + FX_FILESIZE SavedPos = m_pSyntax->SavePos(); + + const int32_t recordsize = 20; + std::vector<char> buf(1024 * recordsize + 1); + buf[1024 * recordsize] = '\0'; + + int32_t nBlocks = count / 1024 + 1; + for (int32_t block = 0; block < nBlocks; block++) { + int32_t block_size = block == nBlocks - 1 ? count % 1024 : 1024; + FX_DWORD dwReadSize = block_size * recordsize; + if ((FX_FILESIZE)(dwStartPos + dwReadSize) > m_pSyntax->m_FileLen) + return FALSE; + + if (!m_pSyntax->ReadBlock(reinterpret_cast<uint8_t*>(buf.data()), + dwReadSize)) { + return FALSE; + } + + for (int32_t i = 0; i < block_size; i++) { + FX_DWORD objnum = start_objnum + block * 1024 + i; + char* pEntry = &buf[i * recordsize]; + if (pEntry[17] == 'f') { + m_ObjectInfo[objnum].pos = 0; + m_ObjectInfo[objnum].type = 0; + } else { + int32_t offset = FXSYS_atoi(pEntry); + if (offset == 0) { + for (int32_t c = 0; c < 10; c++) { + if (!std::isdigit(pEntry[c])) + return FALSE; + } + } + + m_ObjectInfo[objnum].pos = offset; + int32_t version = FXSYS_atoi(pEntry + 11); + if (version >= 1) + m_bVersionUpdated = TRUE; + + m_ObjectInfo[objnum].gennum = version; + if (m_ObjectInfo[objnum].pos < m_pSyntax->m_FileLen) + m_SortedOffset.insert(m_ObjectInfo[objnum].pos); + + m_ObjectInfo[objnum].type = 1; + } + } + } + m_pSyntax->RestorePos(SavedPos + count * recordsize); + return TRUE; +} + +bool CPDF_Parser::LoadCrossRefV4(FX_FILESIZE pos, + FX_FILESIZE streampos, + FX_BOOL bSkip) { + m_pSyntax->RestorePos(pos); + if (m_pSyntax->GetKeyword() != "xref") + return false; + + m_SortedOffset.insert(pos); + if (streampos) + m_SortedOffset.insert(streampos); + + while (1) { + FX_FILESIZE SavedPos = m_pSyntax->SavePos(); + bool bIsNumber; + CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber); + if (word.IsEmpty()) + return false; + + if (!bIsNumber) { + m_pSyntax->RestorePos(SavedPos); + break; + } + + FX_DWORD start_objnum = FXSYS_atoui(word); + if (start_objnum >= kMaxObjectNumber) + return false; + + FX_DWORD count = m_pSyntax->GetDirectNum(); + m_pSyntax->ToNextWord(); + SavedPos = m_pSyntax->SavePos(); + const int32_t recordsize = 20; + + m_dwXrefStartObjNum = start_objnum; + if (!bSkip) { + std::vector<char> buf(1024 * recordsize + 1); + buf[1024 * recordsize] = '\0'; + + int32_t nBlocks = count / 1024 + 1; + for (int32_t block = 0; block < nBlocks; block++) { + int32_t block_size = block == nBlocks - 1 ? count % 1024 : 1024; + m_pSyntax->ReadBlock(reinterpret_cast<uint8_t*>(buf.data()), + block_size * recordsize); + + for (int32_t i = 0; i < block_size; i++) { + FX_DWORD objnum = start_objnum + block * 1024 + i; + char* pEntry = &buf[i * recordsize]; + if (pEntry[17] == 'f') { + m_ObjectInfo[objnum].pos = 0; + m_ObjectInfo[objnum].type = 0; + } else { + FX_FILESIZE offset = (FX_FILESIZE)FXSYS_atoi64(pEntry); + if (offset == 0) { + for (int32_t c = 0; c < 10; c++) { + if (!std::isdigit(pEntry[c])) + return false; + } + } + + m_ObjectInfo[objnum].pos = offset; + int32_t version = FXSYS_atoi(pEntry + 11); + if (version >= 1) + m_bVersionUpdated = TRUE; + + m_ObjectInfo[objnum].gennum = version; + if (m_ObjectInfo[objnum].pos < m_pSyntax->m_FileLen) + m_SortedOffset.insert(m_ObjectInfo[objnum].pos); + + m_ObjectInfo[objnum].type = 1; + } + } + } + } + m_pSyntax->RestorePos(SavedPos + count * recordsize); + } + return !streampos || LoadCrossRefV5(&streampos, FALSE); +} + +FX_BOOL CPDF_Parser::LoadAllCrossRefV5(FX_FILESIZE xrefpos) { + if (!LoadCrossRefV5(&xrefpos, TRUE)) + return FALSE; + + std::set<FX_FILESIZE> seen_xrefpos; + while (xrefpos) { + seen_xrefpos.insert(xrefpos); + if (!LoadCrossRefV5(&xrefpos, FALSE)) + return FALSE; + + // Check for circular references. + if (pdfium::ContainsKey(seen_xrefpos, xrefpos)) + return FALSE; + } + m_ObjectStreamMap.clear(); + m_bXRefStream = TRUE; + return TRUE; +} + +FX_BOOL CPDF_Parser::RebuildCrossRef() { + m_ObjectInfo.clear(); + m_SortedOffset.clear(); + if (m_pTrailer) { + m_pTrailer->Release(); + m_pTrailer = nullptr; + } + + ParserState state = ParserState::kDefault; + + int32_t inside_index = 0; + FX_DWORD objnum = 0; + FX_DWORD gennum = 0; + int32_t depth = 0; + + const FX_DWORD kBufferSize = 4096; + std::vector<uint8_t> buffer(kBufferSize); + + FX_FILESIZE pos = m_pSyntax->m_HeaderOffset; + FX_FILESIZE start_pos = 0; + FX_FILESIZE start_pos1 = 0; + FX_FILESIZE last_obj = -1; + FX_FILESIZE last_xref = -1; + FX_FILESIZE last_trailer = -1; + + while (pos < m_pSyntax->m_FileLen) { + const FX_FILESIZE saved_pos = pos; + bool bOverFlow = false; + FX_DWORD size = + std::min((FX_DWORD)(m_pSyntax->m_FileLen - pos), kBufferSize); + if (!m_pSyntax->m_pFileAccess->ReadBlock(buffer.data(), pos, size)) + break; + + for (FX_DWORD i = 0; i < size; i++) { + uint8_t byte = buffer[i]; + switch (state) { + case ParserState::kDefault: + if (PDFCharIsWhitespace(byte)) { + state = ParserState::kWhitespace; + } else if (std::isdigit(byte)) { + --i; + state = ParserState::kWhitespace; + } else if (byte == '%') { + inside_index = 0; + state = ParserState::kComment; + } else if (byte == '(') { + state = ParserState::kString; + depth = 1; + } else if (byte == '<') { + inside_index = 1; + state = ParserState::kHexString; + } else if (byte == '\\') { + state = ParserState::kEscapedString; + } else if (byte == 't') { + state = ParserState::kTrailer; + inside_index = 1; + } + break; + + case ParserState::kWhitespace: + if (std::isdigit(byte)) { + start_pos = pos + i; + state = ParserState::kObjNum; + objnum = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte)); + } else if (byte == 't') { + state = ParserState::kTrailer; + inside_index = 1; + } else if (byte == 'x') { + state = ParserState::kXref; + inside_index = 1; + } else if (!PDFCharIsWhitespace(byte)) { + --i; + state = ParserState::kDefault; + } + break; + + case ParserState::kObjNum: + if (std::isdigit(byte)) { + objnum = + objnum * 10 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte)); + } else if (PDFCharIsWhitespace(byte)) { + state = ParserState::kPostObjNum; + } else { + --i; + state = ParserState::kEndObj; + inside_index = 0; + } + break; + + case ParserState::kPostObjNum: + if (std::isdigit(byte)) { + start_pos1 = pos + i; + state = ParserState::kGenNum; + gennum = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte)); + } else if (byte == 't') { + state = ParserState::kTrailer; + inside_index = 1; + } else if (!PDFCharIsWhitespace(byte)) { + --i; + state = ParserState::kDefault; + } + break; + + case ParserState::kGenNum: + if (std::isdigit(byte)) { + gennum = + gennum * 10 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte)); + } else if (PDFCharIsWhitespace(byte)) { + state = ParserState::kPostGenNum; + } else { + --i; + state = ParserState::kDefault; + } + break; + + case ParserState::kPostGenNum: + if (byte == 'o') { + state = ParserState::kBeginObj; + inside_index = 1; + } else if (std::isdigit(byte)) { + objnum = gennum; + gennum = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte)); + start_pos = start_pos1; + start_pos1 = pos + i; + state = ParserState::kGenNum; + } else if (byte == 't') { + state = ParserState::kTrailer; + inside_index = 1; + } else if (!PDFCharIsWhitespace(byte)) { + --i; + state = ParserState::kDefault; + } + break; + + case ParserState::kBeginObj: + switch (inside_index) { + case 1: + if (byte != 'b') { + --i; + state = ParserState::kDefault; + } else { + inside_index++; + } + break; + case 2: + if (byte != 'j') { + --i; + state = ParserState::kDefault; + } else { + inside_index++; + } + break; + case 3: + if (PDFCharIsWhitespace(byte) || PDFCharIsDelimiter(byte)) { + FX_FILESIZE obj_pos = start_pos - m_pSyntax->m_HeaderOffset; + m_SortedOffset.insert(obj_pos); + last_obj = start_pos; + FX_FILESIZE obj_end = 0; + CPDF_Object* pObject = ParseIndirectObjectAtByStrict( + m_pDocument, obj_pos, objnum, &obj_end); + if (CPDF_Stream* pStream = ToStream(pObject)) { + if (CPDF_Dictionary* pDict = pStream->GetDict()) { + if ((pDict->KeyExist("Type")) && + (pDict->GetStringBy("Type") == "XRef" && + pDict->KeyExist("Size"))) { + CPDF_Object* pRoot = pDict->GetElement("Root"); + if (pRoot && pRoot->GetDict() && + pRoot->GetDict()->GetElement("Pages")) { + if (m_pTrailer) + m_pTrailer->Release(); + m_pTrailer = ToDictionary(pDict->Clone()); + } + } + } + } + + FX_FILESIZE offset = 0; + m_pSyntax->RestorePos(obj_pos); + offset = m_pSyntax->FindTag("obj", 0); + if (offset == -1) + offset = 0; + else + offset += 3; + + FX_FILESIZE nLen = obj_end - obj_pos - offset; + if ((FX_DWORD)nLen > size - i) { + pos = obj_end + m_pSyntax->m_HeaderOffset; + bOverFlow = true; + } else { + i += (FX_DWORD)nLen; + } + + if (!m_ObjectInfo.empty() && IsValidObjectNumber(objnum) && + m_ObjectInfo[objnum].pos) { + if (pObject) { + FX_DWORD oldgen = GetObjectGenNum(objnum); + m_ObjectInfo[objnum].pos = obj_pos; + m_ObjectInfo[objnum].gennum = gennum; + if (oldgen != gennum) + m_bVersionUpdated = TRUE; + } + } else { + m_ObjectInfo[objnum].pos = obj_pos; + m_ObjectInfo[objnum].type = 1; + m_ObjectInfo[objnum].gennum = gennum; + } + + if (pObject) + pObject->Release(); + } + --i; + state = ParserState::kDefault; + break; + } + break; + + case ParserState::kTrailer: + if (inside_index == 7) { + if (PDFCharIsWhitespace(byte) || PDFCharIsDelimiter(byte)) { + last_trailer = pos + i - 7; + m_pSyntax->RestorePos(pos + i - m_pSyntax->m_HeaderOffset); + + CPDF_Object* pObj = m_pSyntax->GetObject(m_pDocument, 0, 0, true); + if (pObj) { + if (!pObj->IsDictionary() && !pObj->AsStream()) { + pObj->Release(); + } else { + CPDF_Stream* pStream = pObj->AsStream(); + if (CPDF_Dictionary* pTrailer = + pStream ? pStream->GetDict() : pObj->AsDictionary()) { + if (m_pTrailer) { + CPDF_Object* pRoot = pTrailer->GetElement("Root"); + CPDF_Reference* pRef = ToReference(pRoot); + if (!pRoot || + (pRef && IsValidObjectNumber(pRef->GetRefObjNum()) && + m_ObjectInfo[pRef->GetRefObjNum()].pos != 0)) { + auto it = pTrailer->begin(); + while (it != pTrailer->end()) { + const CFX_ByteString& key = it->first; + CPDF_Object* pElement = it->second; + ++it; + FX_DWORD dwObjNum = + pElement ? pElement->GetObjNum() : 0; + if (dwObjNum) { + m_pTrailer->SetAtReference(key, m_pDocument, + dwObjNum); + } else { + m_pTrailer->SetAt(key, pElement->Clone()); + } + } + } + pObj->Release(); + } else { + if (pObj->IsStream()) { + m_pTrailer = ToDictionary(pTrailer->Clone()); + pObj->Release(); + } else { + m_pTrailer = pTrailer; + } + + FX_FILESIZE dwSavePos = m_pSyntax->SavePos(); + CFX_ByteString strWord = m_pSyntax->GetKeyword(); + if (!strWord.Compare("startxref")) { + bool bNumber; + CFX_ByteString bsOffset = + m_pSyntax->GetNextWord(&bNumber); + if (bNumber) + m_LastXRefOffset = FXSYS_atoi(bsOffset); + } + m_pSyntax->RestorePos(dwSavePos); + } + } else { + pObj->Release(); + } + } + } + } + --i; + state = ParserState::kDefault; + } else if (byte == "trailer"[inside_index]) { + inside_index++; + } else { + --i; + state = ParserState::kDefault; + } + break; + + case ParserState::kXref: + if (inside_index == 4) { + last_xref = pos + i - 4; + state = ParserState::kWhitespace; + } else if (byte == "xref"[inside_index]) { + inside_index++; + } else { + --i; + state = ParserState::kDefault; + } + break; + + case ParserState::kComment: + if (PDFCharIsLineEnding(byte)) + state = ParserState::kDefault; + break; + + case ParserState::kString: + if (byte == ')') { + if (depth > 0) + depth--; + } else if (byte == '(') { + depth++; + } + + if (!depth) + state = ParserState::kDefault; + break; + + case ParserState::kHexString: + if (byte == '>' || (byte == '<' && inside_index == 1)) + state = ParserState::kDefault; + inside_index = 0; + break; + + case ParserState::kEscapedString: + if (PDFCharIsDelimiter(byte) || PDFCharIsWhitespace(byte)) { + --i; + state = ParserState::kDefault; + } + break; + + case ParserState::kEndObj: + if (PDFCharIsWhitespace(byte)) { + state = ParserState::kDefault; + } else if (byte == '%' || byte == '(' || byte == '<' || + byte == '\\') { + state = ParserState::kDefault; + --i; + } else if (inside_index == 6) { + state = ParserState::kDefault; + --i; + } else if (byte == "endobj"[inside_index]) { + inside_index++; + } + break; + } + + if (bOverFlow) { + size = 0; + break; + } + } + pos += size; + + // If the position has not changed at all in a loop iteration, then break + // out to prevent infinite looping. + if (pos == saved_pos) + break; + } + + if (last_xref != -1 && last_xref > last_obj) + last_trailer = last_xref; + else if (last_trailer == -1 || last_xref < last_obj) + last_trailer = m_pSyntax->m_FileLen; + + m_SortedOffset.insert(last_trailer - m_pSyntax->m_HeaderOffset); + return m_pTrailer && !m_ObjectInfo.empty(); +} + +FX_BOOL CPDF_Parser::LoadCrossRefV5(FX_FILESIZE* pos, FX_BOOL bMainXRef) { + CPDF_Object* pObject = ParseIndirectObjectAt(m_pDocument, *pos, 0); + if (!pObject) + return FALSE; + + if (m_pDocument) { + FX_BOOL bInserted = FALSE; + CPDF_Dictionary* pDict = m_pDocument->GetRoot(); + if (!pDict || pDict->GetObjNum() != pObject->m_ObjNum) { + bInserted = m_pDocument->InsertIndirectObject(pObject->m_ObjNum, pObject); + } else { + if (pObject->IsStream()) + pObject->Release(); + } + + if (!bInserted) + return FALSE; + } + + CPDF_Stream* pStream = pObject->AsStream(); + if (!pStream) + return FALSE; + + *pos = pStream->GetDict()->GetIntegerBy("Prev"); + int32_t size = pStream->GetDict()->GetIntegerBy("Size"); + if (size < 0) { + pStream->Release(); + return FALSE; + } + + if (bMainXRef) { + m_pTrailer = ToDictionary(pStream->GetDict()->Clone()); + ShrinkObjectMap(size); + for (auto& it : m_ObjectInfo) + it.second.type = 0; + } else { + m_Trailers.Add(ToDictionary(pStream->GetDict()->Clone())); + } + + std::vector<std::pair<int32_t, int32_t>> arrIndex; + CPDF_Array* pArray = pStream->GetDict()->GetArrayBy("Index"); + if (pArray) { + FX_DWORD nPairSize = pArray->GetCount() / 2; + for (FX_DWORD i = 0; i < nPairSize; i++) { + CPDF_Object* pStartNumObj = pArray->GetElement(i * 2); + CPDF_Object* pCountObj = pArray->GetElement(i * 2 + 1); + + if (ToNumber(pStartNumObj) && ToNumber(pCountObj)) { + int nStartNum = pStartNumObj->GetInteger(); + int nCount = pCountObj->GetInteger(); + if (nStartNum >= 0 && nCount > 0) + arrIndex.push_back(std::make_pair(nStartNum, nCount)); + } + } + } + + if (arrIndex.size() == 0) + arrIndex.push_back(std::make_pair(0, size)); + + pArray = pStream->GetDict()->GetArrayBy("W"); + if (!pArray) { + pStream->Release(); + return FALSE; + } + + CFX_DWordArray WidthArray; + FX_SAFE_DWORD dwAccWidth = 0; + for (FX_DWORD i = 0; i < pArray->GetCount(); i++) { + WidthArray.Add(pArray->GetIntegerAt(i)); + dwAccWidth += WidthArray[i]; + } + + if (!dwAccWidth.IsValid() || WidthArray.GetSize() < 3) { + pStream->Release(); + return FALSE; + } + + FX_DWORD totalWidth = dwAccWidth.ValueOrDie(); + CPDF_StreamAcc acc; + acc.LoadAllData(pStream); + + const uint8_t* pData = acc.GetData(); + FX_DWORD dwTotalSize = acc.GetSize(); + FX_DWORD segindex = 0; + for (FX_DWORD i = 0; i < arrIndex.size(); i++) { + int32_t startnum = arrIndex[i].first; + if (startnum < 0) + continue; + + m_dwXrefStartObjNum = + pdfium::base::checked_cast<FX_DWORD, int32_t>(startnum); + FX_DWORD count = + pdfium::base::checked_cast<FX_DWORD, int32_t>(arrIndex[i].second); + FX_SAFE_DWORD dwCaculatedSize = segindex; + dwCaculatedSize += count; + dwCaculatedSize *= totalWidth; + if (!dwCaculatedSize.IsValid() || + dwCaculatedSize.ValueOrDie() > dwTotalSize) { + continue; + } + + const uint8_t* segstart = pData + segindex * totalWidth; + FX_SAFE_DWORD dwMaxObjNum = startnum; + dwMaxObjNum += count; + FX_DWORD dwV5Size = m_ObjectInfo.empty() ? 0 : GetLastObjNum() + 1; + if (!dwMaxObjNum.IsValid() || dwMaxObjNum.ValueOrDie() > dwV5Size) + continue; + + for (FX_DWORD j = 0; j < count; j++) { + int32_t type = 1; + const uint8_t* entrystart = segstart + j * totalWidth; + if (WidthArray[0]) + type = GetVarInt(entrystart, WidthArray[0]); + + if (GetObjectType(startnum + j) == 255) { + FX_FILESIZE offset = + GetVarInt(entrystart + WidthArray[0], WidthArray[1]); + m_ObjectInfo[startnum + j].pos = offset; + m_SortedOffset.insert(offset); + continue; + } + + if (GetObjectType(startnum + j)) + continue; + + m_ObjectInfo[startnum + j].type = type; + if (type == 0) { + m_ObjectInfo[startnum + j].pos = 0; + } else { + FX_FILESIZE offset = + GetVarInt(entrystart + WidthArray[0], WidthArray[1]); + m_ObjectInfo[startnum + j].pos = offset; + if (type == 1) { + m_SortedOffset.insert(offset); + } else { + if (offset < 0 || !IsValidObjectNumber(offset)) { + pStream->Release(); + return FALSE; + } + m_ObjectInfo[offset].type = 255; + } + } + } + segindex += count; + } + pStream->Release(); + return TRUE; +} + +CPDF_Array* CPDF_Parser::GetIDArray() { + CPDF_Object* pID = m_pTrailer ? m_pTrailer->GetElement("ID") : nullptr; + if (!pID) + return nullptr; + + if (CPDF_Reference* pRef = pID->AsReference()) { + pID = ParseIndirectObject(nullptr, pRef->GetRefObjNum()); + m_pTrailer->SetAt("ID", pID); + } + return ToArray(pID); +} + +FX_DWORD CPDF_Parser::GetRootObjNum() { + CPDF_Reference* pRef = + ToReference(m_pTrailer ? m_pTrailer->GetElement("Root") : nullptr); + return pRef ? pRef->GetRefObjNum() : 0; +} + +FX_DWORD CPDF_Parser::GetInfoObjNum() { + CPDF_Reference* pRef = + ToReference(m_pTrailer ? m_pTrailer->GetElement("Info") : nullptr); + return pRef ? pRef->GetRefObjNum() : 0; +} + +FX_BOOL CPDF_Parser::IsFormStream(FX_DWORD objnum, FX_BOOL& bForm) { + bForm = FALSE; + if (!IsValidObjectNumber(objnum)) + return TRUE; + + if (GetObjectType(objnum) == 0) + return TRUE; + + if (GetObjectType(objnum) == 2) + return TRUE; + + FX_FILESIZE pos = m_ObjectInfo[objnum].pos; + auto it = m_SortedOffset.find(pos); + if (it == m_SortedOffset.end()) + return TRUE; + + if (++it == m_SortedOffset.end()) + return FALSE; + + FX_FILESIZE size = *it - pos; + FX_FILESIZE SavedPos = m_pSyntax->SavePos(); + m_pSyntax->RestorePos(pos); + + const char kFormStream[] = "/Form\0stream"; + const CFX_ByteStringC kFormStreamStr(kFormStream, sizeof(kFormStream) - 1); + bForm = m_pSyntax->SearchMultiWord(kFormStreamStr, TRUE, size) == 0; + m_pSyntax->RestorePos(SavedPos); + return TRUE; +} + +CPDF_Object* CPDF_Parser::ParseIndirectObject( + CPDF_IndirectObjectHolder* pObjList, + FX_DWORD objnum) { + if (!IsValidObjectNumber(objnum)) + return nullptr; + + // Prevent circular parsing the same object. + if (pdfium::ContainsKey(m_ParsingObjNums, objnum)) + return nullptr; + ScopedSetInsertion<FX_DWORD> local_insert(&m_ParsingObjNums, objnum); + + if (GetObjectType(objnum) == 1 || GetObjectType(objnum) == 255) { + FX_FILESIZE pos = m_ObjectInfo[objnum].pos; + if (pos <= 0) + return nullptr; + return ParseIndirectObjectAt(pObjList, pos, objnum); + } + if (GetObjectType(objnum) != 2) + return nullptr; + + CPDF_StreamAcc* pObjStream = GetObjectStream(m_ObjectInfo[objnum].pos); + if (!pObjStream) + return nullptr; + + ScopedFileStream file(FX_CreateMemoryStream( + (uint8_t*)pObjStream->GetData(), (size_t)pObjStream->GetSize(), FALSE)); + CPDF_SyntaxParser syntax; + syntax.InitParser(file.get(), 0); + const int32_t offset = GetStreamFirst(pObjStream); + + // Read object numbers from |pObjStream| into a cache. + if (!pdfium::ContainsKey(m_ObjCache, pObjStream)) { + for (int32_t i = GetStreamNCount(pObjStream); i > 0; --i) { + FX_DWORD thisnum = syntax.GetDirectNum(); + FX_DWORD thisoff = syntax.GetDirectNum(); + m_ObjCache[pObjStream][thisnum] = thisoff; + } + } + + const auto it = m_ObjCache[pObjStream].find(objnum); + if (it == m_ObjCache[pObjStream].end()) + return nullptr; + + syntax.RestorePos(offset + it->second); + return syntax.GetObject(pObjList, 0, 0, true); +} + +CPDF_StreamAcc* CPDF_Parser::GetObjectStream(FX_DWORD objnum) { + auto it = m_ObjectStreamMap.find(objnum); + if (it != m_ObjectStreamMap.end()) + return it->second.get(); + + if (!m_pDocument) + return nullptr; + + const CPDF_Stream* pStream = ToStream(m_pDocument->GetIndirectObject(objnum)); + if (!pStream) + return nullptr; + + CPDF_StreamAcc* pStreamAcc = new CPDF_StreamAcc; + pStreamAcc->LoadAllData(pStream); + m_ObjectStreamMap[objnum].reset(pStreamAcc); + return pStreamAcc; +} + +FX_FILESIZE CPDF_Parser::GetObjectSize(FX_DWORD objnum) const { + if (!IsValidObjectNumber(objnum)) + return 0; + + if (GetObjectType(objnum) == 2) + objnum = GetObjectPositionOrZero(objnum); + + if (GetObjectType(objnum) != 1 && GetObjectType(objnum) != 255) + return 0; + + FX_FILESIZE offset = GetObjectPositionOrZero(objnum); + if (offset == 0) + return 0; + + auto it = m_SortedOffset.find(offset); + if (it == m_SortedOffset.end() || ++it == m_SortedOffset.end()) + return 0; + + return *it - offset; +} + +void CPDF_Parser::GetIndirectBinary(FX_DWORD objnum, + uint8_t*& pBuffer, + FX_DWORD& size) { + pBuffer = nullptr; + size = 0; + if (!IsValidObjectNumber(objnum)) + return; + + if (GetObjectType(objnum) == 2) { + CPDF_StreamAcc* pObjStream = GetObjectStream(m_ObjectInfo[objnum].pos); + if (!pObjStream) + return; + + int32_t offset = GetStreamFirst(pObjStream); + const uint8_t* pData = pObjStream->GetData(); + FX_DWORD totalsize = pObjStream->GetSize(); + ScopedFileStream file( + FX_CreateMemoryStream((uint8_t*)pData, (size_t)totalsize, FALSE)); + + CPDF_SyntaxParser syntax; + syntax.InitParser(file.get(), 0); + for (int i = GetStreamNCount(pObjStream); i > 0; --i) { + FX_DWORD thisnum = syntax.GetDirectNum(); + FX_DWORD thisoff = syntax.GetDirectNum(); + if (thisnum != objnum) + continue; + + if (i == 1) { + size = totalsize - (thisoff + offset); + } else { + syntax.GetDirectNum(); // Skip nextnum. + FX_DWORD nextoff = syntax.GetDirectNum(); + size = nextoff - thisoff; + } + + pBuffer = FX_Alloc(uint8_t, size); + FXSYS_memcpy(pBuffer, pData + thisoff + offset, size); + return; + } + return; + } + + if (GetObjectType(objnum) != 1) + return; + + FX_FILESIZE pos = m_ObjectInfo[objnum].pos; + if (pos == 0) + return; + + FX_FILESIZE SavedPos = m_pSyntax->SavePos(); + m_pSyntax->RestorePos(pos); + + bool bIsNumber; + CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber); + if (!bIsNumber) { + m_pSyntax->RestorePos(SavedPos); + return; + } + + FX_DWORD parser_objnum = FXSYS_atoui(word); + if (parser_objnum && parser_objnum != objnum) { + m_pSyntax->RestorePos(SavedPos); + return; + } + + word = m_pSyntax->GetNextWord(&bIsNumber); + if (!bIsNumber) { + m_pSyntax->RestorePos(SavedPos); + return; + } + + if (m_pSyntax->GetKeyword() != "obj") { + m_pSyntax->RestorePos(SavedPos); + return; + } + + auto it = m_SortedOffset.find(pos); + if (it == m_SortedOffset.end() || ++it == m_SortedOffset.end()) { + m_pSyntax->RestorePos(SavedPos); + return; + } + + FX_FILESIZE nextoff = *it; + FX_BOOL bNextOffValid = FALSE; + if (nextoff != pos) { + m_pSyntax->RestorePos(nextoff); + word = m_pSyntax->GetNextWord(&bIsNumber); + if (word == "xref") { + bNextOffValid = TRUE; + } else if (bIsNumber) { + word = m_pSyntax->GetNextWord(&bIsNumber); + if (bIsNumber && m_pSyntax->GetKeyword() == "obj") { + bNextOffValid = TRUE; + } + } + } + + if (!bNextOffValid) { + m_pSyntax->RestorePos(pos); + while (1) { + if (m_pSyntax->GetKeyword() == "endobj") + break; + + if (m_pSyntax->SavePos() == m_pSyntax->m_FileLen) + break; + } + nextoff = m_pSyntax->SavePos(); + } + + size = (FX_DWORD)(nextoff - pos); + pBuffer = FX_Alloc(uint8_t, size); + m_pSyntax->RestorePos(pos); + m_pSyntax->ReadBlock(pBuffer, size); + m_pSyntax->RestorePos(SavedPos); +} + +CPDF_Object* CPDF_Parser::ParseIndirectObjectAt( + CPDF_IndirectObjectHolder* pObjList, + FX_FILESIZE pos, + FX_DWORD objnum) { + FX_FILESIZE SavedPos = m_pSyntax->SavePos(); + m_pSyntax->RestorePos(pos); + bool bIsNumber; + CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber); + if (!bIsNumber) { + m_pSyntax->RestorePos(SavedPos); + return nullptr; + } + + FX_FILESIZE objOffset = m_pSyntax->SavePos(); + objOffset -= word.GetLength(); + FX_DWORD parser_objnum = FXSYS_atoui(word); + if (objnum && parser_objnum != objnum) { + m_pSyntax->RestorePos(SavedPos); + return nullptr; + } + + word = m_pSyntax->GetNextWord(&bIsNumber); + if (!bIsNumber) { + m_pSyntax->RestorePos(SavedPos); + return nullptr; + } + + FX_DWORD parser_gennum = FXSYS_atoui(word); + if (m_pSyntax->GetKeyword() != "obj") { + m_pSyntax->RestorePos(SavedPos); + return nullptr; + } + + CPDF_Object* pObj = + m_pSyntax->GetObject(pObjList, objnum, parser_gennum, true); + m_pSyntax->SavePos(); + + CFX_ByteString bsWord = m_pSyntax->GetKeyword(); + if (bsWord == "endobj") + m_pSyntax->SavePos(); + + m_pSyntax->RestorePos(SavedPos); + if (pObj) { + if (!objnum) + pObj->m_ObjNum = parser_objnum; + pObj->m_GenNum = parser_gennum; + } + return pObj; +} + +CPDF_Object* CPDF_Parser::ParseIndirectObjectAtByStrict( + CPDF_IndirectObjectHolder* pObjList, + FX_FILESIZE pos, + FX_DWORD objnum, + FX_FILESIZE* pResultPos) { + FX_FILESIZE SavedPos = m_pSyntax->SavePos(); + m_pSyntax->RestorePos(pos); + + bool bIsNumber; + CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber); + if (!bIsNumber) { + m_pSyntax->RestorePos(SavedPos); + return nullptr; + } + + FX_DWORD parser_objnum = FXSYS_atoui(word); + if (objnum && parser_objnum != objnum) { + m_pSyntax->RestorePos(SavedPos); + return nullptr; + } + + word = m_pSyntax->GetNextWord(&bIsNumber); + if (!bIsNumber) { + m_pSyntax->RestorePos(SavedPos); + return nullptr; + } + + FX_DWORD gennum = FXSYS_atoui(word); + if (m_pSyntax->GetKeyword() != "obj") { + m_pSyntax->RestorePos(SavedPos); + return nullptr; + } + + CPDF_Object* pObj = m_pSyntax->GetObjectByStrict(pObjList, objnum, gennum); + if (pResultPos) + *pResultPos = m_pSyntax->m_Pos; + + m_pSyntax->RestorePos(SavedPos); + return pObj; +} + +CPDF_Dictionary* CPDF_Parser::LoadTrailerV4() { + 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(); +} + +FX_DWORD CPDF_Parser::GetPermissions(FX_BOOL bCheckRevision) { + if (!m_pSecurityHandler) + return (FX_DWORD)-1; + + FX_DWORD dwPermission = m_pSecurityHandler->GetPermissions(); + if (m_pEncryptDict && m_pEncryptDict->GetStringBy("Filter") == "Standard") { + dwPermission &= 0xFFFFFFFC; + dwPermission |= 0xFFFFF0C0; + if (bCheckRevision && m_pEncryptDict->GetIntegerBy("R") == 2) + dwPermission &= 0xFFFFF0FF; + } + return dwPermission; +} + +FX_BOOL CPDF_Parser::IsLinearizedFile(IFX_FileRead* pFileAccess, + FX_DWORD offset) { + m_pSyntax->InitParser(pFileAccess, offset); + m_pSyntax->RestorePos(m_pSyntax->m_HeaderOffset + 9); + + FX_FILESIZE SavedPos = m_pSyntax->SavePos(); + bool bIsNumber; + CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber); + if (!bIsNumber) + return FALSE; + + FX_DWORD objnum = FXSYS_atoui(word); + word = m_pSyntax->GetNextWord(&bIsNumber); + if (!bIsNumber) + return FALSE; + + FX_DWORD gennum = FXSYS_atoui(word); + if (m_pSyntax->GetKeyword() != "obj") { + m_pSyntax->RestorePos(SavedPos); + return FALSE; + } + + m_pLinearized = m_pSyntax->GetObject(nullptr, objnum, gennum, true); + if (!m_pLinearized) + return FALSE; + + CPDF_Dictionary* pDict = m_pLinearized->GetDict(); + if (pDict && pDict->GetElement("Linearized")) { + m_pSyntax->GetNextWord(nullptr); + + CPDF_Object* pLen = pDict->GetElement("L"); + if (!pLen) { + m_pLinearized->Release(); + m_pLinearized = nullptr; + return FALSE; + } + + if (pLen->GetInteger() != (int)pFileAccess->GetSize()) + return FALSE; + + if (CPDF_Number* pNo = ToNumber(pDict->GetElement("P"))) + m_dwFirstPageNo = pNo->GetInteger(); + + if (CPDF_Number* pTable = ToNumber(pDict->GetElement("T"))) + m_LastXRefOffset = pTable->GetInteger(); + + return TRUE; + } + m_pLinearized->Release(); + m_pLinearized = nullptr; + return FALSE; +} + +CPDF_Parser::Error CPDF_Parser::StartAsyncParse(IFX_FileRead* pFileAccess) { + CloseParser(); + m_bXRefStream = FALSE; + m_LastXRefOffset = 0; + m_bOwnFileRead = true; + + int32_t offset = GetHeaderOffset(pFileAccess); + if (offset == -1) + return FORMAT_ERROR; + + if (!IsLinearizedFile(pFileAccess, offset)) { + m_pSyntax->m_pFileAccess = nullptr; + return StartParse(pFileAccess); + } + + m_pDocument = new CPDF_Document(this); + FX_FILESIZE dwFirstXRefOffset = m_pSyntax->SavePos(); + + FX_BOOL bXRefRebuilt = FALSE; + FX_BOOL bLoadV4 = FALSE; + if (!(bLoadV4 = LoadCrossRefV4(dwFirstXRefOffset, 0, FALSE)) && + !LoadCrossRefV5(&dwFirstXRefOffset, TRUE)) { + if (!RebuildCrossRef()) + return FORMAT_ERROR; + + bXRefRebuilt = TRUE; + m_LastXRefOffset = 0; + } + + if (bLoadV4) { + m_pTrailer = LoadTrailerV4(); + if (!m_pTrailer) + return SUCCESS; + + int32_t xrefsize = GetDirectInteger(m_pTrailer, "Size"); + if (xrefsize > 0) + ShrinkObjectMap(xrefsize); + } + + Error eRet = SetEncryptHandler(); + if (eRet != SUCCESS) + return eRet; + + m_pDocument->LoadAsynDoc(m_pLinearized->GetDict()); + if (!m_pDocument->GetRoot() || m_pDocument->GetPageCount() == 0) { + if (bXRefRebuilt) + return FORMAT_ERROR; + + ReleaseEncryptHandler(); + if (!RebuildCrossRef()) + return FORMAT_ERROR; + + eRet = SetEncryptHandler(); + if (eRet != SUCCESS) + return eRet; + + m_pDocument->LoadAsynDoc(m_pLinearized->GetDict()); + if (!m_pDocument->GetRoot()) + return FORMAT_ERROR; + } + + if (GetRootObjNum() == 0) { + ReleaseEncryptHandler(); + if (!RebuildCrossRef() || GetRootObjNum() == 0) + return FORMAT_ERROR; + + eRet = SetEncryptHandler(); + if (eRet != SUCCESS) + return eRet; + } + + if (m_pSecurityHandler && m_pSecurityHandler->IsMetadataEncrypted()) { + if (CPDF_Reference* pMetadata = + ToReference(m_pDocument->GetRoot()->GetElement("Metadata"))) + m_pSyntax->m_MetadataObjnum = pMetadata->GetRefObjNum(); + } + return SUCCESS; +} + +FX_BOOL CPDF_Parser::LoadLinearizedAllCrossRefV5(FX_FILESIZE xrefpos) { + if (!LoadCrossRefV5(&xrefpos, FALSE)) + return FALSE; + + std::set<FX_FILESIZE> seen_xrefpos; + while (xrefpos) { + seen_xrefpos.insert(xrefpos); + if (!LoadCrossRefV5(&xrefpos, FALSE)) + return FALSE; + + // Check for circular references. + if (pdfium::ContainsKey(seen_xrefpos, xrefpos)) + return FALSE; + } + m_ObjectStreamMap.clear(); + m_bXRefStream = TRUE; + return TRUE; +} + +CPDF_Parser::Error CPDF_Parser::LoadLinearizedMainXRefTable() { + FX_DWORD dwSaveMetadataObjnum = m_pSyntax->m_MetadataObjnum; + m_pSyntax->m_MetadataObjnum = 0; + if (m_pTrailer) { + m_pTrailer->Release(); + m_pTrailer = nullptr; + } + + m_pSyntax->RestorePos(m_LastXRefOffset - m_pSyntax->m_HeaderOffset); + uint8_t ch = 0; + FX_DWORD dwCount = 0; + m_pSyntax->GetNextChar(ch); + while (PDFCharIsWhitespace(ch)) { + ++dwCount; + if (m_pSyntax->m_FileLen >= + (FX_FILESIZE)(m_pSyntax->SavePos() + m_pSyntax->m_HeaderOffset)) { + break; + } + m_pSyntax->GetNextChar(ch); + } + m_LastXRefOffset += dwCount; + m_ObjectStreamMap.clear(); + m_ObjCache.clear(); + + 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; +} |