// Copyright 2016 PDFium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
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#include "core/fpdfapi/fpdf_parser/cpdf_syntax_parser.h"
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#include <vector>
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#include "core/fpdfapi/fpdf_parser/cpdf_boolean.h"
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#include "core/fpdfapi/fpdf_parser/cpdf_crypto_handler.h"
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#include "core/fpdfapi/fpdf_parser/cpdf_null.h"
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#include "core/fpdfapi/fpdf_parser/fpdf_parser_utility.h"
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#include "core/fpdfapi/fpdf_parser/include/cpdf_array.h"
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#include "core/fpdfapi/fpdf_parser/include/cpdf_dictionary.h"
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#include "core/fpdfapi/fpdf_parser/include/cpdf_name.h"
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#include "core/fpdfapi/fpdf_parser/include/cpdf_number.h"
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#include "core/fpdfapi/fpdf_parser/include/cpdf_reference.h"
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#include "core/fpdfapi/fpdf_parser/include/cpdf_stream.h"
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#include "core/fpdfapi/fpdf_parser/include/cpdf_string.h"
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#include "core/fpdfapi/fpdf_parser/include/fpdf_parser_decode.h"
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#include "core/fpdfapi/include/cpdf_modulemgr.h"
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#include "core/fxcrt/include/fx_ext.h"
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#include "third_party/base/numerics/safe_math.h"
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namespace {
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struct SearchTagRecord {
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CFX_ByteStringC m_bsTag;
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FX_STRSIZE m_Offset;
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};
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} // namespace
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// static
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int CPDF_SyntaxParser::s_CurrentRecursionDepth = 0;
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CPDF_SyntaxParser::CPDF_SyntaxParser()
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: m_MetadataObjnum(0),
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m_pFileAccess(nullptr),
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m_pFileBuf(nullptr),
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m_BufSize(CPDF_ModuleMgr::kFileBufSize) {}
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CPDF_SyntaxParser::~CPDF_SyntaxParser() {
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FX_Free(m_pFileBuf);
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}
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FX_BOOL CPDF_SyntaxParser::GetCharAt(FX_FILESIZE pos, uint8_t& ch) {
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CFX_AutoRestorer<FX_FILESIZE> save_pos(&m_Pos);
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m_Pos = pos;
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return GetNextChar(ch);
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}
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FX_BOOL CPDF_SyntaxParser::GetNextChar(uint8_t& ch) {
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FX_FILESIZE pos = m_Pos + m_HeaderOffset;
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if (pos >= m_FileLen)
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return FALSE;
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if (m_BufOffset >= pos || (FX_FILESIZE)(m_BufOffset + m_BufSize) <= pos) {
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FX_FILESIZE read_pos = pos;
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uint32_t read_size = m_BufSize;
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if ((FX_FILESIZE)read_size > m_FileLen)
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read_size = (uint32_t)m_FileLen;
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if ((FX_FILESIZE)(read_pos + read_size) > m_FileLen) {
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if (m_FileLen < (FX_FILESIZE)read_size) {
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read_pos = 0;
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read_size = (uint32_t)m_FileLen;
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} else {
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read_pos = m_FileLen - read_size;
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}
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}
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if (!m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size))
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return FALSE;
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m_BufOffset = read_pos;
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}
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ch = m_pFileBuf[pos - m_BufOffset];
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m_Pos++;
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return TRUE;
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}
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FX_BOOL CPDF_SyntaxParser::GetCharAtBackward(FX_FILESIZE pos, uint8_t& ch) {
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pos += m_HeaderOffset;
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if (pos >= m_FileLen)
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return FALSE;
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if (m_BufOffset >= pos || (FX_FILESIZE)(m_BufOffset + m_BufSize) <= pos) {
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FX_FILESIZE read_pos;
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if (pos < (FX_FILESIZE)m_BufSize)
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read_pos = 0;
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else
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read_pos = pos - m_BufSize + 1;
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uint32_t read_size = m_BufSize;
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if ((FX_FILESIZE)(read_pos + read_size) > m_FileLen) {
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if (m_FileLen < (FX_FILESIZE)read_size) {
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read_pos = 0;
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read_size = (uint32_t)m_FileLen;
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} else {
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read_pos = m_FileLen - read_size;
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}
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}
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if (!m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size))
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return FALSE;
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m_BufOffset = read_pos;
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}
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ch = m_pFileBuf[pos - m_BufOffset];
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return TRUE;
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}
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FX_BOOL CPDF_SyntaxParser::ReadBlock(uint8_t* pBuf, uint32_t size) {
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if (!m_pFileAccess->ReadBlock(pBuf, m_Pos + m_HeaderOffset, size))
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return FALSE;
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m_Pos += size;
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return TRUE;
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}
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void CPDF_SyntaxParser::GetNextWordInternal(bool* bIsNumber) {
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m_WordSize = 0;
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if (bIsNumber)
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*bIsNumber = true;
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uint8_t ch;
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if (!GetNextChar(ch))
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return;
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while (1) {
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while (PDFCharIsWhitespace(ch)) {
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if (!GetNextChar(ch))
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return;
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}
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if (ch != '%')
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break;
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while (1) {
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if (!GetNextChar(ch))
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return;
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if (PDFCharIsLineEnding(ch))
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break;
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}
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}
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if (PDFCharIsDelimiter(ch)) {
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if (bIsNumber)
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*bIsNumber = false;
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m_WordBuffer[m_WordSize++] = ch;
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if (ch == '/') {
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while (1) {
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if (!GetNextChar(ch))
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return;
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if (!PDFCharIsOther(ch) && !PDFCharIsNumeric(ch)) {
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m_Pos--;
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return;
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}
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if (m_WordSize < sizeof(m_WordBuffer) - 1)
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m_WordBuffer[m_WordSize++] = ch;
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}
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} else if (ch == '<') {
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if (!GetNextChar(ch))
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return;
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if (ch == '<')
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m_WordBuffer[m_WordSize++] = ch;
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else
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m_Pos--;
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} else if (ch == '>') {
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if (!GetNextChar(ch))
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return;
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if (ch == '>')
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m_WordBuffer[m_WordSize++] = ch;
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else
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m_Pos--;
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}
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return;
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}
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while (1) {
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if (m_WordSize < sizeof(m_WordBuffer) - 1)
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m_WordBuffer[m_WordSize++] = ch;
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if (!PDFCharIsNumeric(ch)) {
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if (bIsNumber)
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*bIsNumber = false;
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}
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if (!GetNextChar(ch))
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return;
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if (PDFCharIsDelimiter(ch) || PDFCharIsWhitespace(ch)) {
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m_Pos--;
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break;
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}
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}
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}
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CFX_ByteString CPDF_SyntaxParser::ReadString() {
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uint8_t ch;
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if (!GetNextChar(ch))
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return CFX_ByteString();
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CFX_ByteTextBuf buf;
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int32_t parlevel = 0;
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int32_t status = 0;
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int32_t iEscCode = 0;
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while (1) {
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switch (status) {
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case 0:
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if (ch == ')') {
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if (parlevel == 0) {
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return buf.MakeString();
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}
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parlevel--;
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buf.AppendChar(')');
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} else if (ch == '(') {
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parlevel++;
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buf.AppendChar('(');
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} else if (ch == '\\') {
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status = 1;
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} else {
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buf.AppendChar(ch);
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}
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break;
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case 1:
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if (ch >= '0' && ch <= '7') {
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iEscCode = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch));
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status = 2;
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break;
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}
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if (ch == 'n') {
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buf.AppendChar('\n');
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} else if (ch == 'r') {
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buf.AppendChar('\r');
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} else if (ch == 't') {
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buf.AppendChar('\t');
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} else if (ch == 'b') {
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buf.AppendChar('\b');
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} else if (ch == 'f') {
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buf.AppendChar('\f');
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} else if (ch == '\r') {
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status = 4;
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break;
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} else if (ch != '\n') {
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buf.AppendChar(ch);
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}
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status = 0;
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break;
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case 2:
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if (ch >= '0' && ch <= '7') {
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iEscCode =
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iEscCode * 8 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch));
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status = 3;
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} else {
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buf.AppendChar(iEscCode);
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status = 0;
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continue;
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}
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break;
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case 3:
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if (ch >= '0' && ch <= '7') {
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iEscCode =
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iEscCode * 8 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch));
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buf.AppendChar(iEscCode);
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status = 0;
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} else {
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buf.AppendChar(iEscCode);
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status = 0;
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continue;
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}
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break;
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case 4:
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status = 0;
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if (ch != '\n')
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continue;
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break;
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}
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if (!GetNextChar(ch))
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break;
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}
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GetNextChar(ch);
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return buf.MakeString();
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}
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CFX_ByteString CPDF_SyntaxParser::ReadHexString() {
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uint8_t ch;
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if (!GetNextChar(ch))
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return CFX_ByteString();
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CFX_ByteTextBuf buf;
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bool bFirst = true;
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uint8_t code = 0;
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while (1) {
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if (ch == '>')
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break;
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if (std::isxdigit(ch)) {
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int val = FXSYS_toHexDigit(ch);
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if (bFirst) {
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code = val * 16;
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} else {
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code += val;
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buf.AppendByte(code);
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}
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bFirst = !bFirst;
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}
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if (!GetNextChar(ch))
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break;
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}
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if (!bFirst)
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buf.AppendByte(code);
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return buf.MakeString();
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}
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void CPDF_SyntaxParser::ToNextLine() {
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uint8_t ch;
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while (GetNextChar(ch)) {
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if (ch == '\n')
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break;
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if (ch == '\r') {
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GetNextChar(ch);
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if (ch != '\n')
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--m_Pos;
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break;
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}
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}
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}
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void CPDF_SyntaxParser::ToNextWord() {
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uint8_t ch;
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if (!GetNextChar(ch))
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return;
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while (1) {
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while (PDFCharIsWhitespace(ch)) {
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if (!GetNextChar(ch))
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return;
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}
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if (ch != '%')
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break;
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while (1) {
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if (!GetNextChar(ch))
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return;
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if (PDFCharIsLineEnding(ch))
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break;
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}
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}
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m_Pos--;
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}
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CFX_ByteString CPDF_SyntaxParser::GetNextWord(bool* bIsNumber) {
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GetNextWordInternal(bIsNumber);
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return CFX_ByteString((const FX_CHAR*)m_WordBuffer, m_WordSize);
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}
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CFX_ByteString CPDF_SyntaxParser::GetKeyword() {
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return GetNextWord(nullptr);
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}
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CPDF_Object* CPDF_SyntaxParser::GetObject(CPDF_IndirectObjectHolder* pObjList,
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uint32_t objnum,
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uint32_t gennum,
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FX_BOOL bDecrypt) {
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CFX_AutoRestorer<int> restorer(&s_CurrentRecursionDepth);
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if (++s_CurrentRecursionDepth > kParserMaxRecursionDepth)
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return nullptr;
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FX_FILESIZE SavedObjPos = m_Pos;
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bool bIsNumber;
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CFX_ByteString word = GetNextWord(&bIsNumber);
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if (word.GetLength() == 0)
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return nullptr;
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if (bIsNumber) {
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FX_FILESIZE SavedPos = m_Pos;
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CFX_ByteString nextword = GetNextWord(&bIsNumber);
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if (bIsNumber) {
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CFX_ByteString nextword2 = GetNextWord(nullptr);
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if (nextword2 == "R")
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return new CPDF_Reference(pObjList, FXSYS_atoui(word.c_str()));
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}
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m_Pos = SavedPos;
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return new CPDF_Number(word.AsStringC());
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}
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if (word == "true" || word == "false")
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return new CPDF_Boolean(word == "true");
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if (word == "null")
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return new CPDF_Null;
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if (word == "(") {
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CFX_ByteString str = ReadString();
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if (m_pCryptoHandler && bDecrypt)
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m_pCryptoHandler->Decrypt(objnum, gennum, str);
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return new CPDF_String(str, FALSE);
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}
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if (word == "<") {
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CFX_ByteString str = ReadHexString();
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if (m_pCryptoHandler && bDecrypt)
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m_pCryptoHandler->Decrypt(objnum, gennum, str);
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return new CPDF_String(str, TRUE);
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}
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if (word == "[") {
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CPDF_Array* pArray = new CPDF_Array;
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while (CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, true))
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pArray->Add(pObj);
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return pArray;
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}
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if (word[0] == '/') {
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return new CPDF_Name(
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PDF_NameDecode(CFX_ByteStringC(m_WordBuffer + 1, m_WordSize - 1)));
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}
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if (word == "<<") {
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int32_t nKeys = 0;
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FX_FILESIZE dwSignValuePos = 0;
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std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict(
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new CPDF_Dictionary);
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while (1) {
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CFX_ByteString key = GetNextWord(nullptr);
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if (key.IsEmpty())
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return nullptr;
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FX_FILESIZE SavedPos = m_Pos - key.GetLength();
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if (key == ">>")
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break;
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if (key == "endobj") {
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m_Pos = SavedPos;
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break;
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}
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if (key[0] != '/')
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continue;
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++nKeys;
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key = PDF_NameDecode(key);
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if (key.IsEmpty())
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continue;
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if (key == "/Contents")
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dwSignValuePos = m_Pos;
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CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, true);
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if (!pObj)
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continue;
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CFX_ByteString keyNoSlash(key.raw_str() + 1, key.GetLength() - 1);
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pDict->SetAt(keyNoSlash, pObj);
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}
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// Only when this is a signature dictionary and has contents, we reset the
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// contents to the un-decrypted form.
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if (pDict->IsSignatureDict() && dwSignValuePos) {
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CFX_AutoRestorer<FX_FILESIZE> save_pos(&m_Pos);
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m_Pos = dwSignValuePos;
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pDict->SetAt("Contents", GetObject(pObjList, objnum, gennum, false));
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}
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FX_FILESIZE SavedPos = m_Pos;
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CFX_ByteString nextword = GetNextWord(nullptr);
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if (nextword != "stream") {
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m_Pos = SavedPos;
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return pDict.release();
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}
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return ReadStream(pDict.release(), objnum, gennum);
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}
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if (word == ">>")
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m_Pos = SavedObjPos;
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return nullptr;
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}
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CPDF_Object* CPDF_SyntaxParser::GetObjectByStrict(
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CPDF_IndirectObjectHolder* pObjList,
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uint32_t objnum,
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uint32_t gennum) {
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CFX_AutoRestorer<int> restorer(&s_CurrentRecursionDepth);
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if (++s_CurrentRecursionDepth > kParserMaxRecursionDepth)
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return nullptr;
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FX_FILESIZE SavedObjPos = m_Pos;
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bool bIsNumber;
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CFX_ByteString word = GetNextWord(&bIsNumber);
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if (word.GetLength() == 0)
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return nullptr;
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if (bIsNumber) {
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FX_FILESIZE SavedPos = m_Pos;
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CFX_ByteString nextword = GetNextWord(&bIsNumber);
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if (bIsNumber) {
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CFX_ByteString nextword2 = GetNextWord(nullptr);
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if (nextword2 == "R")
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return new CPDF_Reference(pObjList, FXSYS_atoui(word.c_str()));
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}
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m_Pos = SavedPos;
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return new CPDF_Number(word.AsStringC());
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}
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if (word == "true" || word == "false")
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return new CPDF_Boolean(word == "true");
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if (word == "null")
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return new CPDF_Null;
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if (word == "(") {
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CFX_ByteString str = ReadString();
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if (m_pCryptoHandler)
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m_pCryptoHandler->Decrypt(objnum, gennum, str);
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return new CPDF_String(str, FALSE);
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}
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if (word == "<") {
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CFX_ByteString str = ReadHexString();
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if (m_pCryptoHandler)
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m_pCryptoHandler->Decrypt(objnum, gennum, str);
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return new CPDF_String(str, TRUE);
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}
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if (word == "[") {
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std::unique_ptr<CPDF_Array, ReleaseDeleter<CPDF_Array>> pArray(
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new CPDF_Array);
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while (CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, true))
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pArray->Add(pObj);
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return m_WordBuffer[0] == ']' ? pArray.release() : nullptr;
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}
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if (word[0] == '/') {
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return new CPDF_Name(
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PDF_NameDecode(CFX_ByteStringC(m_WordBuffer + 1, m_WordSize - 1)));
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}
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if (word == "<<") {
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std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict(
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new CPDF_Dictionary);
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while (1) {
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FX_FILESIZE SavedPos = m_Pos;
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CFX_ByteString key = GetNextWord(nullptr);
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if (key.IsEmpty())
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return nullptr;
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if (key == ">>")
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break;
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if (key == "endobj") {
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m_Pos = SavedPos;
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break;
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}
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if (key[0] != '/')
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continue;
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key = PDF_NameDecode(key);
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std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> obj(
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GetObject(pObjList, objnum, gennum, true));
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if (!obj) {
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uint8_t ch;
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while (GetNextChar(ch) && ch != 0x0A && ch != 0x0D) {
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continue;
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}
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return nullptr;
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}
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if (key.GetLength() > 1) {
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pDict->SetAt(CFX_ByteString(key.c_str() + 1, key.GetLength() - 1),
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obj.release());
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}
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}
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FX_FILESIZE SavedPos = m_Pos;
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CFX_ByteString nextword = GetNextWord(nullptr);
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if (nextword != "stream") {
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m_Pos = SavedPos;
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return pDict.release();
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}
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return ReadStream(pDict.release(), objnum, gennum);
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}
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if (word == ">>")
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m_Pos = SavedObjPos;
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return nullptr;
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}
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unsigned int CPDF_SyntaxParser::ReadEOLMarkers(FX_FILESIZE pos) {
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unsigned char byte1 = 0;
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unsigned char byte2 = 0;
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GetCharAt(pos, byte1);
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GetCharAt(pos + 1, byte2);
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if (byte1 == '\r' && byte2 == '\n')
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return 2;
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if (byte1 == '\r' || byte1 == '\n')
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return 1;
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return 0;
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}
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CPDF_Stream* CPDF_SyntaxParser::ReadStream(CPDF_Dictionary* pDict,
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uint32_t objnum,
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uint32_t gennum) {
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CPDF_Object* pLenObj = pDict->GetObjectBy("Length");
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FX_FILESIZE len = -1;
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CPDF_Reference* pLenObjRef = ToReference(pLenObj);
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bool differingObjNum = !pLenObjRef || (pLenObjRef->GetObjList() &&
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pLenObjRef->GetRefObjNum() != objnum);
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if (pLenObj && differingObjNum)
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len = pLenObj->GetInteger();
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// Locate the start of stream.
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ToNextLine();
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FX_FILESIZE streamStartPos = m_Pos;
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const CFX_ByteStringC kEndStreamStr("endstream");
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const CFX_ByteStringC kEndObjStr("endobj");
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CPDF_CryptoHandler* pCryptoHandler =
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objnum == (uint32_t)m_MetadataObjnum ? nullptr : m_pCryptoHandler.get();
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if (!pCryptoHandler) {
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FX_BOOL bSearchForKeyword = TRUE;
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if (len >= 0) {
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pdfium::base::CheckedNumeric<FX_FILESIZE> pos = m_Pos;
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pos += len;
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if (pos.IsValid() && pos.ValueOrDie() < m_FileLen)
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m_Pos = pos.ValueOrDie();
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m_Pos += ReadEOLMarkers(m_Pos);
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FXSYS_memset(m_WordBuffer, 0, kEndStreamStr.GetLength() + 1);
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GetNextWordInternal(nullptr);
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// Earlier version of PDF specification doesn't require EOL marker before
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// 'endstream' keyword. If keyword 'endstream' follows the bytes in
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// specified length, it signals the end of stream.
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if (FXSYS_memcmp(m_WordBuffer, kEndStreamStr.raw_str(),
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kEndStreamStr.GetLength()) == 0) {
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bSearchForKeyword = FALSE;
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}
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}
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if (bSearchForKeyword) {
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// If len is not available, len needs to be calculated
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// by searching the keywords "endstream" or "endobj".
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m_Pos = streamStartPos;
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FX_FILESIZE endStreamOffset = 0;
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while (endStreamOffset >= 0) {
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endStreamOffset = FindTag(kEndStreamStr, 0);
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// 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.raw_str(),
|
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.raw_str();
|
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;
|
}
|
|
// Ensure that the input byte string happens to be nul-terminated. This
|
// need not be the case, but the loop below uses this guarantee to put
|
// the last pattern into the vector.
|
ASSERT(tags[tags.GetLength()] == 0);
|
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_bsTag = tags.Mid(start, 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_bsTag[pat.m_Offset] != byte) {
|
pat.m_Offset = (pat.m_bsTag[0] == byte) ? 1 : 0;
|
continue;
|
}
|
|
++pat.m_Offset;
|
if (pat.m_Offset != pat.m_bsTag.GetLength())
|
continue;
|
|
if (!bWholeWord || IsWholeWord(pos - pat.m_bsTag.GetLength(), limit,
|
pat.m_bsTag, FALSE)) {
|
return i;
|
}
|
|
pat.m_Offset = (pat.m_bsTag[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<CPDF_CryptoHandler> pCryptoHandler) {
|
m_pCryptoHandler = std::move(pCryptoHandler);
|
}
|
