mirror of
https://github.com/ONLYOFFICE/core.git
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281 lines
7.5 KiB
C++
281 lines
7.5 KiB
C++
/*
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* (c) Copyright Ascensio System SIA 2010-2016
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*
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* This program is a free software product. You can redistribute it and/or
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* modify it under the terms of the GNU Affero General Public License (AGPL)
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* version 3 as published by the Free Software Foundation. In accordance with
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* Section 7(a) of the GNU AGPL its Section 15 shall be amended to the effect
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* that Ascensio System SIA expressly excludes the warranty of non-infringement
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* of any third-party rights.
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*
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* This program is distributed WITHOUT ANY WARRANTY; without even the implied
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. For
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* details, see the GNU AGPL at: http://www.gnu.org/licenses/agpl-3.0.html
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*
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* You can contact Ascensio System SIA at Lubanas st. 125a-25, Riga, Latvia,
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* EU, LV-1021.
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*
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* The interactive user interfaces in modified source and object code versions
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* of the Program must display Appropriate Legal Notices, as required under
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* Section 5 of the GNU AGPL version 3.
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*
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* Pursuant to Section 7(b) of the License you must retain the original Product
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* logo when distributing the program. Pursuant to Section 7(e) we decline to
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* grant you any rights under trademark law for use of our trademarks.
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*
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* All the Product's GUI elements, including illustrations and icon sets, as
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* well as technical writing content are licensed under the terms of the
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* Creative Commons Attribution-ShareAlike 4.0 International. See the License
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* terms at http://creativecommons.org/licenses/by-sa/4.0/legalcode
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*
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*/
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#include <stddef.h>
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#include "Object.h"
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#include "Array.h"
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#include "Dict.h"
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#include "Decrypt.h"
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#include "Parser.h"
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#include "XRef.h"
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namespace PdfReader
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{
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Parser::Parser(XRef *pXref, Lexer *pLexer, bool bAllowStreams)
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{
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m_pXref = pXref;
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m_pLexer = pLexer;
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m_nInlineImage = 0;
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m_bAllowStreams = bAllowStreams;
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m_pLexer->GetObject(&m_oBuffer1);
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m_pLexer->GetObject(&m_oBuffer2);
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}
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Parser::~Parser()
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{
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m_oBuffer1.Free();
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m_oBuffer2.Free();
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delete m_pLexer;
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}
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Object *Parser::GetObject(Object *pObject, unsigned char *sDecryptKey, CryptAlgorithm eEncryptAlgorithm, int nKeyLength, int nObjectNum, int nObjectGen)
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{
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Stream *pStream = NULL;
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Object oTemp;
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int nNum = 0;
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// Обновляем буффер после Inline image data
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if (m_nInlineImage == 2)
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{
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m_oBuffer1.Free();
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m_oBuffer2.Free();
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m_pLexer->GetObject(&m_oBuffer1);
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m_pLexer->GetObject(&m_oBuffer2);
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m_nInlineImage = 0;
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}
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// Массив
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if (m_oBuffer1.IsCommand("["))
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{
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Shift();
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pObject->InitArray(m_pXref);
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while (!m_oBuffer1.IsCommand("]") && !m_oBuffer1.IsEOF())
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pObject->ArrayAdd(GetObject(&oTemp, sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen));
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if (m_oBuffer1.IsEOF())
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{
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// TO DO: Error "End of file inside array"
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}
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Shift();
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}
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else if (m_oBuffer1.IsCommand("<<")) // Dictionary или Stream
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{
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Shift();
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pObject->InitDict(m_pXref);
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while (!m_oBuffer1.IsCommand(">>") && !m_oBuffer1.IsEOF())
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{
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if (!m_oBuffer1.IsName())
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{
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// TO DO: Error "Dictionary key must be a name object"
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Shift();
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}
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else
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{
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char *sKey = CopyString(m_oBuffer1.GetName());
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Shift();
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if (m_oBuffer1.IsEOF() || m_oBuffer1.IsError())
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{
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MemUtilsFree(sKey);
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break;
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}
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pObject->DictAdd(sKey, GetObject(&oTemp, sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen));
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}
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}
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if (m_oBuffer1.IsEOF())
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{
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// TO DO: Error "End of file inside dictionary"
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}
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// Объекты Stream Objects не допустимы внутри потока или объекта типа Stream Objects
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if (m_bAllowStreams && m_oBuffer2.IsCommand("stream"))
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{
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if ((pStream = CreateStream(pObject, sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen)))
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{
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pObject->InitStream(pStream);
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}
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else
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{
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pObject->Free();
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pObject->InitError();
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}
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}
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else
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{
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Shift();
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}
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}
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else if (m_oBuffer1.IsInt()) // Либо ссылка, либо число
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{
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nNum = m_oBuffer1.GetInt();
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Shift();
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if (m_oBuffer1.IsInt() && m_oBuffer2.IsCommand("R"))
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{
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pObject->InitRef(nNum, m_oBuffer1.GetInt());
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Shift();
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Shift();
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}
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else
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{
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pObject->InitInt(nNum);
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}
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}
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else if (m_oBuffer1.IsString() && sDecryptKey) // строка
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{
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StringExt *seTemp = m_oBuffer1.GetString();
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StringExt *seRes = new StringExt();
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oTemp.InitNull();
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DecryptStream *pDecrypt = new DecryptStream(new MemoryStream(seTemp->GetBuffer(), 0, seTemp->GetLength(), &oTemp), sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen);
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pDecrypt->Reset();
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int nChar = 0;
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while ((nChar = pDecrypt->GetChar()) != EOF)
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{
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seRes->Append((char)nChar);
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}
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delete pDecrypt;
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pObject->InitString(seRes);
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Shift();
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}
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else // простой объект
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{
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m_oBuffer1.Copy(pObject);
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Shift();
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}
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return pObject;
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}
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Stream *Parser::CreateStream(Object *pDict, unsigned char *sDecryptKey, CryptAlgorithm eEncryptAlgorithm, int nKeyLength, int nObjectNum, int nObjectGen)
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{
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Object oTemp;
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unsigned int nLength, unEndPos;
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m_pLexer->SkipToNextLine();
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unsigned int unPos = m_pLexer->GetPos();
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// Считываем длину
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pDict->DictLookup("Length", &oTemp);
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if (oTemp.IsInt())
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{
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nLength = (unsigned int)oTemp.GetInt();
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oTemp.Free();
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}
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else
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{
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oTemp.Free();
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unsigned int unEndPos = unPos;
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while (!m_oBuffer2.IsCommand("endstream") && !m_oBuffer2.IsEOF())
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{
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unEndPos = m_pLexer->GetPos();
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Shift();
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}
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nLength = unEndPos - unPos;
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m_pLexer->SetPos(unPos);
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// Оставим на всякий случай заглушку
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if (nLength <= 0)
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nLength = 5000;
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}
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// Меняем длину, если файл поврежден
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if (m_pXref && m_pXref->GetStreamEnd(unPos, &unEndPos))
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{
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nLength = unEndPos - unPos;
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}
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// В сильно повержденных файлах PDF, выставляем конец потока сразу
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// после его начала
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if (!m_pLexer->GetStream())
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{
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return NULL;
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}
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BaseStream *pBaseStream = m_pLexer->GetStream()->GetBaseStream();
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// Пропускаем данный потока
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m_pLexer->SetPos(unPos + nLength);
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// Проверяем 'endstream'
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Shift(); // '>>'
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Shift(); // 'endstream'
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if (m_oBuffer1.IsCommand("endstream"))
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{
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Shift();
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}
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else
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{
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// TO DO : Error "Missing 'endstream'"
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// Заплатка для поврежденных файлов:
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nLength += 5000;
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}
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Stream *pStream = pBaseStream->MakeSubStream(unPos, true, nLength, pDict);
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// Decryption
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if (sDecryptKey)
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{
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pStream = new DecryptStream(pStream, sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen);
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}
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// Filters
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pStream = pStream->AddFilters(pDict);
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return pStream;
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}
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void Parser::Shift()
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{
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if (m_nInlineImage > 0)
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{
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if (m_nInlineImage < 2)
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{
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++m_nInlineImage;
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}
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else
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{
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// В поврежденном потоке, если 'ID' появляется в середине потока,
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// нужно сбросить параметры
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m_nInlineImage = 0;
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}
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}
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else if (m_oBuffer2.IsCommand("ID"))
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{
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m_pLexer->SkipChar(); // пропускаем символ после команды 'ID'
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m_nInlineImage = 1;
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}
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m_oBuffer1.Free();
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m_oBuffer1 = m_oBuffer2;
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if (m_nInlineImage > 0) // не буфферизируем данные Inline Image
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m_oBuffer2.InitNull();
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else
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m_pLexer->GetObject(&m_oBuffer2);
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}
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} |