| // 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/cpdf_syntax_parser.h" |
| |
| #include <vector> |
| |
| #include "core/fpdfapi/fpdf_parser/cpdf_boolean.h" |
| #include "core/fpdfapi/fpdf_parser/cpdf_null.h" |
| #include "core/fpdfapi/fpdf_parser/fpdf_parser_utility.h" |
| #include "core/fpdfapi/fpdf_parser/include/cpdf_array.h" |
| #include "core/fpdfapi/fpdf_parser/include/cpdf_dictionary.h" |
| #include "core/fpdfapi/fpdf_parser/include/cpdf_name.h" |
| #include "core/fpdfapi/fpdf_parser/include/cpdf_number.h" |
| #include "core/fpdfapi/fpdf_parser/include/cpdf_reference.h" |
| #include "core/fpdfapi/fpdf_parser/include/cpdf_stream.h" |
| #include "core/fpdfapi/fpdf_parser/include/cpdf_string.h" |
| #include "core/fpdfapi/fpdf_parser/include/fpdf_parser_decode.h" |
| #include "core/fpdfapi/fpdf_parser/ipdf_crypto_handler.h" |
| #include "core/fpdfapi/include/cpdf_modulemgr.h" |
| #include "core/fxcrt/include/fx_ext.h" |
| #include "third_party/base/numerics/safe_math.h" |
| |
| namespace { |
| |
| struct SearchTagRecord { |
| const char* m_pTag; |
| uint32_t m_Len; |
| uint32_t m_Offset; |
| }; |
| |
| } // namespace |
| |
| // static |
| int CPDF_SyntaxParser::s_CurrentRecursionDepth = 0; |
| |
| CPDF_SyntaxParser::CPDF_SyntaxParser() |
| : m_MetadataObjnum(0), |
| m_pFileAccess(nullptr), |
| m_pFileBuf(nullptr), |
| m_BufSize(CPDF_ModuleMgr::kFileBufSize) {} |
| |
| CPDF_SyntaxParser::~CPDF_SyntaxParser() { |
| FX_Free(m_pFileBuf); |
| } |
| |
| FX_BOOL CPDF_SyntaxParser::GetCharAt(FX_FILESIZE pos, uint8_t& ch) { |
| CFX_AutoRestorer<FX_FILESIZE> save_pos(&m_Pos); |
| m_Pos = pos; |
| return GetNextChar(ch); |
| } |
| |
| FX_BOOL CPDF_SyntaxParser::GetNextChar(uint8_t& ch) { |
| FX_FILESIZE pos = m_Pos + m_HeaderOffset; |
| if (pos >= m_FileLen) |
| return FALSE; |
| |
| if (m_BufOffset >= pos || (FX_FILESIZE)(m_BufOffset + m_BufSize) <= pos) { |
| FX_FILESIZE read_pos = pos; |
| uint32_t read_size = m_BufSize; |
| if ((FX_FILESIZE)read_size > m_FileLen) |
| read_size = (uint32_t)m_FileLen; |
| |
| if ((FX_FILESIZE)(read_pos + read_size) > m_FileLen) { |
| if (m_FileLen < (FX_FILESIZE)read_size) { |
| read_pos = 0; |
| read_size = (uint32_t)m_FileLen; |
| } else { |
| read_pos = m_FileLen - read_size; |
| } |
| } |
| |
| if (!m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size)) |
| return FALSE; |
| |
| m_BufOffset = read_pos; |
| } |
| ch = m_pFileBuf[pos - m_BufOffset]; |
| m_Pos++; |
| return TRUE; |
| } |
| |
| FX_BOOL CPDF_SyntaxParser::GetCharAtBackward(FX_FILESIZE pos, uint8_t& ch) { |
| pos += m_HeaderOffset; |
| if (pos >= m_FileLen) |
| return FALSE; |
| |
| if (m_BufOffset >= pos || (FX_FILESIZE)(m_BufOffset + m_BufSize) <= pos) { |
| FX_FILESIZE read_pos; |
| if (pos < (FX_FILESIZE)m_BufSize) |
| read_pos = 0; |
| else |
| read_pos = pos - m_BufSize + 1; |
| |
| uint32_t read_size = m_BufSize; |
| if ((FX_FILESIZE)(read_pos + read_size) > m_FileLen) { |
| if (m_FileLen < (FX_FILESIZE)read_size) { |
| read_pos = 0; |
| read_size = (uint32_t)m_FileLen; |
| } else { |
| read_pos = m_FileLen - read_size; |
| } |
| } |
| |
| if (!m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size)) |
| return FALSE; |
| |
| m_BufOffset = read_pos; |
| } |
| ch = m_pFileBuf[pos - m_BufOffset]; |
| return TRUE; |
| } |
| |
| FX_BOOL CPDF_SyntaxParser::ReadBlock(uint8_t* pBuf, uint32_t size) { |
| if (!m_pFileAccess->ReadBlock(pBuf, m_Pos + m_HeaderOffset, size)) |
| return FALSE; |
| m_Pos += size; |
| return TRUE; |
| } |
| |
| void CPDF_SyntaxParser::GetNextWordInternal(bool* bIsNumber) { |
| m_WordSize = 0; |
| if (bIsNumber) |
| *bIsNumber = true; |
| |
| uint8_t ch; |
| if (!GetNextChar(ch)) |
| return; |
| |
| while (1) { |
| while (PDFCharIsWhitespace(ch)) { |
| if (!GetNextChar(ch)) |
| return; |
| } |
| |
| if (ch != '%') |
| break; |
| |
| while (1) { |
| if (!GetNextChar(ch)) |
| return; |
| if (PDFCharIsLineEnding(ch)) |
| break; |
| } |
| } |
| |
| if (PDFCharIsDelimiter(ch)) { |
| if (bIsNumber) |
| *bIsNumber = false; |
| |
| m_WordBuffer[m_WordSize++] = ch; |
| if (ch == '/') { |
| while (1) { |
| if (!GetNextChar(ch)) |
| return; |
| |
| if (!PDFCharIsOther(ch) && !PDFCharIsNumeric(ch)) { |
| m_Pos--; |
| return; |
| } |
| |
| if (m_WordSize < sizeof(m_WordBuffer) - 1) |
| m_WordBuffer[m_WordSize++] = ch; |
| } |
| } else if (ch == '<') { |
| if (!GetNextChar(ch)) |
| return; |
| |
| if (ch == '<') |
| m_WordBuffer[m_WordSize++] = ch; |
| else |
| m_Pos--; |
| } else if (ch == '>') { |
| if (!GetNextChar(ch)) |
| return; |
| |
| if (ch == '>') |
| m_WordBuffer[m_WordSize++] = ch; |
| else |
| m_Pos--; |
| } |
| return; |
| } |
| |
| while (1) { |
| if (m_WordSize < sizeof(m_WordBuffer) - 1) |
| m_WordBuffer[m_WordSize++] = ch; |
| |
| if (!PDFCharIsNumeric(ch)) { |
| if (bIsNumber) |
| *bIsNumber = false; |
| } |
| |
| if (!GetNextChar(ch)) |
| return; |
| |
| if (PDFCharIsDelimiter(ch) || PDFCharIsWhitespace(ch)) { |
| m_Pos--; |
| break; |
| } |
| } |
| } |
| |
| CFX_ByteString CPDF_SyntaxParser::ReadString() { |
| uint8_t ch; |
| if (!GetNextChar(ch)) |
| return CFX_ByteString(); |
| |
| CFX_ByteTextBuf buf; |
| int32_t parlevel = 0; |
| int32_t status = 0; |
| int32_t iEscCode = 0; |
| while (1) { |
| switch (status) { |
| case 0: |
| if (ch == ')') { |
| if (parlevel == 0) { |
| return buf.GetByteString(); |
| } |
| parlevel--; |
| buf.AppendChar(')'); |
| } else if (ch == '(') { |
| parlevel++; |
| buf.AppendChar('('); |
| } else if (ch == '\\') { |
| status = 1; |
| } else { |
| buf.AppendChar(ch); |
| } |
| break; |
| case 1: |
| if (ch >= '0' && ch <= '7') { |
| iEscCode = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch)); |
| status = 2; |
| break; |
| } |
| |
| if (ch == 'n') { |
| buf.AppendChar('\n'); |
| } else if (ch == 'r') { |
| buf.AppendChar('\r'); |
| } else if (ch == 't') { |
| buf.AppendChar('\t'); |
| } else if (ch == 'b') { |
| buf.AppendChar('\b'); |
| } else if (ch == 'f') { |
| buf.AppendChar('\f'); |
| } else if (ch == '\r') { |
| status = 4; |
| break; |
| } else if (ch != '\n') { |
| buf.AppendChar(ch); |
| } |
| status = 0; |
| break; |
| case 2: |
| if (ch >= '0' && ch <= '7') { |
| iEscCode = |
| iEscCode * 8 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch)); |
| status = 3; |
| } else { |
| buf.AppendChar(iEscCode); |
| status = 0; |
| continue; |
| } |
| break; |
| case 3: |
| if (ch >= '0' && ch <= '7') { |
| iEscCode = |
| iEscCode * 8 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch)); |
| buf.AppendChar(iEscCode); |
| status = 0; |
| } else { |
| buf.AppendChar(iEscCode); |
| status = 0; |
| continue; |
| } |
| break; |
| case 4: |
| status = 0; |
| if (ch != '\n') |
| continue; |
| break; |
| } |
| |
| if (!GetNextChar(ch)) |
| break; |
| } |
| |
| GetNextChar(ch); |
| return buf.GetByteString(); |
| } |
| |
| CFX_ByteString CPDF_SyntaxParser::ReadHexString() { |
| uint8_t ch; |
| if (!GetNextChar(ch)) |
| return CFX_ByteString(); |
| |
| CFX_ByteTextBuf buf; |
| bool bFirst = true; |
| uint8_t code = 0; |
| while (1) { |
| if (ch == '>') |
| break; |
| |
| if (std::isxdigit(ch)) { |
| int val = FXSYS_toHexDigit(ch); |
| if (bFirst) { |
| code = val * 16; |
| } else { |
| code += val; |
| buf.AppendByte(code); |
| } |
| bFirst = !bFirst; |
| } |
| |
| if (!GetNextChar(ch)) |
| break; |
| } |
| if (!bFirst) |
| buf.AppendByte(code); |
| |
| return buf.GetByteString(); |
| } |
| |
| void CPDF_SyntaxParser::ToNextLine() { |
| uint8_t ch; |
| while (GetNextChar(ch)) { |
| if (ch == '\n') |
| break; |
| |
| if (ch == '\r') { |
| GetNextChar(ch); |
| if (ch != '\n') |
| --m_Pos; |
| break; |
| } |
| } |
| } |
| |
| void CPDF_SyntaxParser::ToNextWord() { |
| uint8_t ch; |
| if (!GetNextChar(ch)) |
| return; |
| |
| while (1) { |
| while (PDFCharIsWhitespace(ch)) { |
| if (!GetNextChar(ch)) |
| return; |
| } |
| |
| if (ch != '%') |
| break; |
| |
| while (1) { |
| if (!GetNextChar(ch)) |
| return; |
| if (PDFCharIsLineEnding(ch)) |
| break; |
| } |
| } |
| m_Pos--; |
| } |
| |
| CFX_ByteString CPDF_SyntaxParser::GetNextWord(bool* bIsNumber) { |
| GetNextWordInternal(bIsNumber); |
| return CFX_ByteString((const FX_CHAR*)m_WordBuffer, m_WordSize); |
| } |
| |
| CFX_ByteString CPDF_SyntaxParser::GetKeyword() { |
| return GetNextWord(nullptr); |
| } |
| |
| CPDF_Object* CPDF_SyntaxParser::GetObject(CPDF_IndirectObjectHolder* pObjList, |
| uint32_t objnum, |
| uint32_t gennum, |
| FX_BOOL bDecrypt) { |
| CFX_AutoRestorer<int> restorer(&s_CurrentRecursionDepth); |
| if (++s_CurrentRecursionDepth > kParserMaxRecursionDepth) |
| return nullptr; |
| |
| FX_FILESIZE SavedPos = m_Pos; |
| bool bIsNumber; |
| CFX_ByteString word = GetNextWord(&bIsNumber); |
| if (word.GetLength() == 0) |
| return nullptr; |
| |
| if (bIsNumber) { |
| FX_FILESIZE SavedPos = m_Pos; |
| CFX_ByteString nextword = GetNextWord(&bIsNumber); |
| if (bIsNumber) { |
| CFX_ByteString nextword2 = GetNextWord(nullptr); |
| if (nextword2 == "R") { |
| uint32_t objnum = FXSYS_atoui(word); |
| return new CPDF_Reference(pObjList, objnum); |
| } |
| } |
| m_Pos = SavedPos; |
| return new CPDF_Number(word); |
| } |
| |
| if (word == "true" || word == "false") |
| return new CPDF_Boolean(word == "true"); |
| |
| if (word == "null") |
| return new CPDF_Null; |
| |
| if (word == "(") { |
| CFX_ByteString str = ReadString(); |
| if (m_pCryptoHandler && bDecrypt) |
| m_pCryptoHandler->Decrypt(objnum, gennum, str); |
| return new CPDF_String(str, FALSE); |
| } |
| |
| if (word == "<") { |
| CFX_ByteString str = ReadHexString(); |
| if (m_pCryptoHandler && bDecrypt) |
| m_pCryptoHandler->Decrypt(objnum, gennum, str); |
| |
| return new CPDF_String(str, TRUE); |
| } |
| |
| if (word == "[") { |
| CPDF_Array* pArray = new CPDF_Array; |
| while (CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, true)) |
| pArray->Add(pObj); |
| |
| return pArray; |
| } |
| |
| if (word[0] == '/') { |
| return new CPDF_Name( |
| PDF_NameDecode(CFX_ByteStringC(m_WordBuffer + 1, m_WordSize - 1))); |
| } |
| |
| if (word == "<<") { |
| int32_t nKeys = 0; |
| FX_FILESIZE dwSignValuePos = 0; |
| |
| std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict( |
| new CPDF_Dictionary); |
| while (1) { |
| CFX_ByteString key = GetNextWord(nullptr); |
| if (key.IsEmpty()) |
| return nullptr; |
| |
| FX_FILESIZE SavedPos = m_Pos - key.GetLength(); |
| if (key == ">>") |
| break; |
| |
| if (key == "endobj") { |
| m_Pos = SavedPos; |
| break; |
| } |
| |
| if (key[0] != '/') |
| continue; |
| |
| ++nKeys; |
| key = PDF_NameDecode(key); |
| if (key.IsEmpty()) |
| continue; |
| |
| if (key == "/Contents") |
| dwSignValuePos = m_Pos; |
| |
| CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, true); |
| if (!pObj) |
| continue; |
| |
| CFX_ByteStringC keyNoSlash(key.raw_str() + 1, key.GetLength() - 1); |
| pDict->SetAt(keyNoSlash, pObj); |
| } |
| |
| // Only when this is a signature dictionary and has contents, we reset the |
| // contents to the un-decrypted form. |
| if (pDict->IsSignatureDict() && dwSignValuePos) { |
| CFX_AutoRestorer<FX_FILESIZE> save_pos(&m_Pos); |
| m_Pos = dwSignValuePos; |
| pDict->SetAt("Contents", GetObject(pObjList, objnum, gennum, false)); |
| } |
| |
| FX_FILESIZE SavedPos = m_Pos; |
| CFX_ByteString nextword = GetNextWord(nullptr); |
| if (nextword != "stream") { |
| m_Pos = SavedPos; |
| return pDict.release(); |
| } |
| return ReadStream(pDict.release(), objnum, gennum); |
| } |
| |
| if (word == ">>") |
| m_Pos = SavedPos; |
| |
| return nullptr; |
| } |
| |
| CPDF_Object* CPDF_SyntaxParser::GetObjectByStrict( |
| CPDF_IndirectObjectHolder* pObjList, |
| uint32_t objnum, |
| uint32_t gennum) { |
| CFX_AutoRestorer<int> restorer(&s_CurrentRecursionDepth); |
| if (++s_CurrentRecursionDepth > kParserMaxRecursionDepth) |
| return nullptr; |
| |
| FX_FILESIZE SavedPos = m_Pos; |
| bool bIsNumber; |
| CFX_ByteString word = GetNextWord(&bIsNumber); |
| if (word.GetLength() == 0) |
| return nullptr; |
| |
| if (bIsNumber) { |
| FX_FILESIZE SavedPos = m_Pos; |
| CFX_ByteString nextword = GetNextWord(&bIsNumber); |
| if (bIsNumber) { |
| CFX_ByteString nextword2 = GetNextWord(nullptr); |
| if (nextword2 == "R") |
| return new CPDF_Reference(pObjList, FXSYS_atoui(word)); |
| } |
| m_Pos = SavedPos; |
| return new CPDF_Number(word); |
| } |
| |
| if (word == "true" || word == "false") |
| return new CPDF_Boolean(word == "true"); |
| |
| if (word == "null") |
| return new CPDF_Null; |
| |
| if (word == "(") { |
| CFX_ByteString str = ReadString(); |
| if (m_pCryptoHandler) |
| m_pCryptoHandler->Decrypt(objnum, gennum, str); |
| return new CPDF_String(str, FALSE); |
| } |
| |
| if (word == "<") { |
| CFX_ByteString str = ReadHexString(); |
| if (m_pCryptoHandler) |
| m_pCryptoHandler->Decrypt(objnum, gennum, str); |
| return new CPDF_String(str, TRUE); |
| } |
| |
| if (word == "[") { |
| std::unique_ptr<CPDF_Array, ReleaseDeleter<CPDF_Array>> pArray( |
| new CPDF_Array); |
| while (CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, true)) |
| pArray->Add(pObj); |
| |
| return m_WordBuffer[0] == ']' ? pArray.release() : nullptr; |
| } |
| |
| if (word[0] == '/') { |
| return new CPDF_Name( |
| PDF_NameDecode(CFX_ByteStringC(m_WordBuffer + 1, m_WordSize - 1))); |
| } |
| |
| if (word == "<<") { |
| std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict( |
| new CPDF_Dictionary); |
| while (1) { |
| FX_FILESIZE SavedPos = m_Pos; |
| CFX_ByteString key = GetNextWord(nullptr); |
| if (key.IsEmpty()) |
| return nullptr; |
| |
| if (key == ">>") |
| break; |
| |
| if (key == "endobj") { |
| m_Pos = SavedPos; |
| break; |
| } |
| |
| if (key[0] != '/') |
| continue; |
| |
| key = PDF_NameDecode(key); |
| std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> obj( |
| GetObject(pObjList, objnum, gennum, true)); |
| if (!obj) { |
| uint8_t ch; |
| while (GetNextChar(ch) && ch != 0x0A && ch != 0x0D) { |
| continue; |
| } |
| return nullptr; |
| } |
| |
| if (key.GetLength() > 1) { |
| pDict->SetAt(CFX_ByteStringC(key.c_str() + 1, key.GetLength() - 1), |
| obj.release()); |
| } |
| } |
| |
| FX_FILESIZE SavedPos = m_Pos; |
| CFX_ByteString nextword = GetNextWord(nullptr); |
| if (nextword != "stream") { |
| m_Pos = SavedPos; |
| return pDict.release(); |
| } |
| |
| return ReadStream(pDict.release(), objnum, gennum); |
| } |
| |
| if (word == ">>") |
| m_Pos = SavedPos; |
| |
| return nullptr; |
| } |
| |
| unsigned int CPDF_SyntaxParser::ReadEOLMarkers(FX_FILESIZE pos) { |
| unsigned char byte1 = 0; |
| unsigned char byte2 = 0; |
| |
| GetCharAt(pos, byte1); |
| GetCharAt(pos + 1, byte2); |
| |
| if (byte1 == '\r' && byte2 == '\n') |
| return 2; |
| |
| if (byte1 == '\r' || byte1 == '\n') |
| return 1; |
| |
| return 0; |
| } |
| |
| CPDF_Stream* CPDF_SyntaxParser::ReadStream(CPDF_Dictionary* pDict, |
| uint32_t objnum, |
| uint32_t gennum) { |
| CPDF_Object* pLenObj = pDict->GetElement("Length"); |
| FX_FILESIZE len = -1; |
| CPDF_Reference* pLenObjRef = ToReference(pLenObj); |
| |
| bool differingObjNum = !pLenObjRef || (pLenObjRef->GetObjList() && |
| pLenObjRef->GetRefObjNum() != objnum); |
| if (pLenObj && differingObjNum) |
| len = pLenObj->GetInteger(); |
| |
| // Locate the start of stream. |
| ToNextLine(); |
| FX_FILESIZE streamStartPos = m_Pos; |
| |
| const CFX_ByteStringC kEndStreamStr("endstream"); |
| const CFX_ByteStringC kEndObjStr("endobj"); |
| |
| IPDF_CryptoHandler* pCryptoHandler = |
| objnum == (uint32_t)m_MetadataObjnum ? nullptr : m_pCryptoHandler.get(); |
| if (!pCryptoHandler) { |
| FX_BOOL bSearchForKeyword = TRUE; |
| if (len >= 0) { |
| pdfium::base::CheckedNumeric<FX_FILESIZE> pos = m_Pos; |
| pos += len; |
| if (pos.IsValid() && pos.ValueOrDie() < m_FileLen) |
| m_Pos = pos.ValueOrDie(); |
| |
| m_Pos += ReadEOLMarkers(m_Pos); |
| FXSYS_memset(m_WordBuffer, 0, kEndStreamStr.GetLength() + 1); |
| GetNextWordInternal(nullptr); |
| // Earlier version of PDF specification doesn't require EOL marker before |
| // 'endstream' keyword. If keyword 'endstream' follows the bytes in |
| // specified length, it signals the end of stream. |
| if (FXSYS_memcmp(m_WordBuffer, kEndStreamStr.GetPtr(), |
| kEndStreamStr.GetLength()) == 0) { |
| bSearchForKeyword = FALSE; |
| } |
| } |
| |
| if (bSearchForKeyword) { |
| // If len is not available, len needs to be calculated |
| // by searching the keywords "endstream" or "endobj". |
| m_Pos = streamStartPos; |
| FX_FILESIZE endStreamOffset = 0; |
| while (endStreamOffset >= 0) { |
| endStreamOffset = FindTag(kEndStreamStr, 0); |
| |
| // Can't find "endstream". |
| if (endStreamOffset < 0) |
| break; |
| |
| // Stop searching when "endstream" is found. |
| if (IsWholeWord(m_Pos - kEndStreamStr.GetLength(), m_FileLen, |
| kEndStreamStr, TRUE)) { |
| endStreamOffset = m_Pos - streamStartPos - kEndStreamStr.GetLength(); |
| break; |
| } |
| } |
| |
| m_Pos = streamStartPos; |
| FX_FILESIZE endObjOffset = 0; |
| while (endObjOffset >= 0) { |
| endObjOffset = FindTag(kEndObjStr, 0); |
| |
| // Can't find "endobj". |
| if (endObjOffset < 0) |
| break; |
| |
| // Stop searching when "endobj" is found. |
| if (IsWholeWord(m_Pos - kEndObjStr.GetLength(), m_FileLen, kEndObjStr, |
| TRUE)) { |
| endObjOffset = m_Pos - streamStartPos - kEndObjStr.GetLength(); |
| break; |
| } |
| } |
| |
| // Can't find "endstream" or "endobj". |
| if (endStreamOffset < 0 && endObjOffset < 0) { |
| pDict->Release(); |
| return nullptr; |
| } |
| |
| if (endStreamOffset < 0 && endObjOffset >= 0) { |
| // Correct the position of end stream. |
| endStreamOffset = endObjOffset; |
| } else if (endStreamOffset >= 0 && endObjOffset < 0) { |
| // Correct the position of end obj. |
| endObjOffset = endStreamOffset; |
| } else if (endStreamOffset > endObjOffset) { |
| endStreamOffset = endObjOffset; |
| } |
| |
| len = endStreamOffset; |
| int numMarkers = ReadEOLMarkers(streamStartPos + endStreamOffset - 2); |
| if (numMarkers == 2) { |
| len -= 2; |
| } else { |
| numMarkers = ReadEOLMarkers(streamStartPos + endStreamOffset - 1); |
| if (numMarkers == 1) { |
| len -= 1; |
| } |
| } |
| |
| if (len < 0) { |
| pDict->Release(); |
| return nullptr; |
| } |
| pDict->SetAtInteger("Length", len); |
| } |
| m_Pos = streamStartPos; |
| } |
| |
| if (len < 0) { |
| pDict->Release(); |
| return nullptr; |
| } |
| |
| uint8_t* pData = nullptr; |
| if (len > 0) { |
| pData = FX_Alloc(uint8_t, len); |
| ReadBlock(pData, len); |
| if (pCryptoHandler) { |
| CFX_BinaryBuf dest_buf; |
| dest_buf.EstimateSize(pCryptoHandler->DecryptGetSize(len)); |
| |
| void* context = pCryptoHandler->DecryptStart(objnum, gennum); |
| pCryptoHandler->DecryptStream(context, pData, len, dest_buf); |
| pCryptoHandler->DecryptFinish(context, dest_buf); |
| |
| FX_Free(pData); |
| pData = dest_buf.GetBuffer(); |
| len = dest_buf.GetSize(); |
| dest_buf.DetachBuffer(); |
| } |
| } |
| |
| CPDF_Stream* pStream = new CPDF_Stream(pData, len, pDict); |
| streamStartPos = m_Pos; |
| FXSYS_memset(m_WordBuffer, 0, kEndObjStr.GetLength() + 1); |
| |
| GetNextWordInternal(nullptr); |
| |
| int numMarkers = ReadEOLMarkers(m_Pos); |
| if (m_WordSize == static_cast<unsigned int>(kEndObjStr.GetLength()) && |
| numMarkers != 0 && |
| FXSYS_memcmp(m_WordBuffer, kEndObjStr.GetPtr(), kEndObjStr.GetLength()) == |
| 0) { |
| m_Pos = streamStartPos; |
| } |
| return pStream; |
| } |
| |
| void CPDF_SyntaxParser::InitParser(IFX_FileRead* pFileAccess, |
| uint32_t HeaderOffset) { |
| FX_Free(m_pFileBuf); |
| |
| m_pFileBuf = FX_Alloc(uint8_t, m_BufSize); |
| m_HeaderOffset = HeaderOffset; |
| m_FileLen = pFileAccess->GetSize(); |
| m_Pos = 0; |
| m_pFileAccess = pFileAccess; |
| m_BufOffset = 0; |
| pFileAccess->ReadBlock( |
| m_pFileBuf, 0, |
| (size_t)((FX_FILESIZE)m_BufSize > m_FileLen ? m_FileLen : m_BufSize)); |
| } |
| |
| uint32_t CPDF_SyntaxParser::GetDirectNum() { |
| bool bIsNumber; |
| GetNextWordInternal(&bIsNumber); |
| if (!bIsNumber) |
| return 0; |
| |
| m_WordBuffer[m_WordSize] = 0; |
| return FXSYS_atoui(reinterpret_cast<const FX_CHAR*>(m_WordBuffer)); |
| } |
| |
| bool CPDF_SyntaxParser::IsWholeWord(FX_FILESIZE startpos, |
| FX_FILESIZE limit, |
| const CFX_ByteStringC& tag, |
| FX_BOOL checkKeyword) { |
| const uint32_t taglen = tag.GetLength(); |
| |
| bool bCheckLeft = !PDFCharIsDelimiter(tag[0]) && !PDFCharIsWhitespace(tag[0]); |
| bool bCheckRight = !PDFCharIsDelimiter(tag[taglen - 1]) && |
| !PDFCharIsWhitespace(tag[taglen - 1]); |
| |
| uint8_t ch; |
| if (bCheckRight && startpos + (int32_t)taglen <= limit && |
| GetCharAt(startpos + (int32_t)taglen, ch)) { |
| if (PDFCharIsNumeric(ch) || PDFCharIsOther(ch) || |
| (checkKeyword && PDFCharIsDelimiter(ch))) { |
| return false; |
| } |
| } |
| |
| if (bCheckLeft && startpos > 0 && GetCharAt(startpos - 1, ch)) { |
| if (PDFCharIsNumeric(ch) || PDFCharIsOther(ch) || |
| (checkKeyword && PDFCharIsDelimiter(ch))) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| // TODO(dsinclair): Split into a SearchWordForward and SearchWordBackwards |
| // and drop the bool. |
| FX_BOOL CPDF_SyntaxParser::SearchWord(const CFX_ByteStringC& tag, |
| FX_BOOL bWholeWord, |
| FX_BOOL bForward, |
| FX_FILESIZE limit) { |
| int32_t taglen = tag.GetLength(); |
| if (taglen == 0) |
| return FALSE; |
| |
| FX_FILESIZE pos = m_Pos; |
| int32_t offset = 0; |
| if (!bForward) |
| offset = taglen - 1; |
| |
| const uint8_t* tag_data = tag.GetPtr(); |
| uint8_t byte; |
| while (1) { |
| if (bForward) { |
| if (limit && pos >= m_Pos + limit) |
| return FALSE; |
| |
| if (!GetCharAt(pos, byte)) |
| return FALSE; |
| |
| } else { |
| if (limit && pos <= m_Pos - limit) |
| return FALSE; |
| |
| if (!GetCharAtBackward(pos, byte)) |
| return FALSE; |
| } |
| |
| if (byte == tag_data[offset]) { |
| if (bForward) { |
| offset++; |
| if (offset < taglen) { |
| pos++; |
| continue; |
| } |
| } else { |
| offset--; |
| if (offset >= 0) { |
| pos--; |
| continue; |
| } |
| } |
| |
| FX_FILESIZE startpos = bForward ? pos - taglen + 1 : pos; |
| if (!bWholeWord || IsWholeWord(startpos, limit, tag, FALSE)) { |
| m_Pos = startpos; |
| return TRUE; |
| } |
| } |
| |
| if (bForward) { |
| offset = byte == tag_data[0] ? 1 : 0; |
| pos++; |
| } else { |
| offset = byte == tag_data[taglen - 1] ? taglen - 2 : taglen - 1; |
| pos--; |
| } |
| |
| if (pos < 0) |
| return FALSE; |
| } |
| |
| return FALSE; |
| } |
| |
| int32_t CPDF_SyntaxParser::SearchMultiWord(const CFX_ByteStringC& tags, |
| FX_BOOL bWholeWord, |
| FX_FILESIZE limit) { |
| int32_t ntags = 1; |
| for (int i = 0; i < tags.GetLength(); ++i) { |
| if (tags[i] == 0) |
| ++ntags; |
| } |
| |
| std::vector<SearchTagRecord> patterns(ntags); |
| uint32_t start = 0; |
| uint32_t itag = 0; |
| uint32_t max_len = 0; |
| for (int i = 0; i <= tags.GetLength(); ++i) { |
| if (tags[i] == 0) { |
| uint32_t len = i - start; |
| max_len = std::max(len, max_len); |
| patterns[itag].m_pTag = tags.GetCStr() + start; |
| patterns[itag].m_Len = len; |
| patterns[itag].m_Offset = 0; |
| start = i + 1; |
| ++itag; |
| } |
| } |
| |
| const FX_FILESIZE pos_limit = m_Pos + limit; |
| for (FX_FILESIZE pos = m_Pos; !limit || pos < pos_limit; ++pos) { |
| uint8_t byte; |
| if (!GetCharAt(pos, byte)) |
| break; |
| |
| for (int i = 0; i < ntags; ++i) { |
| SearchTagRecord& pat = patterns[i]; |
| if (pat.m_pTag[pat.m_Offset] != byte) { |
| pat.m_Offset = (pat.m_pTag[0] == byte) ? 1 : 0; |
| continue; |
| } |
| |
| ++pat.m_Offset; |
| if (pat.m_Offset != pat.m_Len) |
| continue; |
| |
| if (!bWholeWord || |
| IsWholeWord(pos - pat.m_Len, limit, |
| CFX_ByteStringC(pat.m_pTag, pat.m_Len), FALSE)) { |
| return i; |
| } |
| |
| pat.m_Offset = (pat.m_pTag[0] == byte) ? 1 : 0; |
| } |
| } |
| return -1; |
| } |
| |
| FX_FILESIZE CPDF_SyntaxParser::FindTag(const CFX_ByteStringC& tag, |
| FX_FILESIZE limit) { |
| int32_t taglen = tag.GetLength(); |
| int32_t match = 0; |
| limit += m_Pos; |
| FX_FILESIZE startpos = m_Pos; |
| |
| while (1) { |
| uint8_t ch; |
| if (!GetNextChar(ch)) |
| return -1; |
| |
| if (ch == tag[match]) { |
| match++; |
| if (match == taglen) |
| return m_Pos - startpos - taglen; |
| } else { |
| match = ch == tag[0] ? 1 : 0; |
| } |
| |
| if (limit && m_Pos == limit) |
| return -1; |
| } |
| return -1; |
| } |
| |
| void CPDF_SyntaxParser::SetEncrypt( |
| std::unique_ptr<IPDF_CryptoHandler> pCryptoHandler) { |
| m_pCryptoHandler = std::move(pCryptoHandler); |
| } |
