core/ASCOfficePDFReader/Parser.cpp

#include "stdafx.h"

#include <stddef.h>
#include "Object.h"
#include "Array.h"
#include "Dict.h"
#include "Decrypt.h"
#include "Parser.h"
#include "XRef.h"

Parser::Parser(XRef *pXref, Lexer *pLexer, BOOL bAllowStreams) 
{
	m_pXref  = pXref;
	m_pLexer = pLexer;
	m_nInlineImage = 0;
	m_bAllowStreams = bAllowStreams;
	m_pLexer->GetObject( &m_oBuffer1 );
	m_pLexer->GetObject( &m_oBuffer2 );
}

Parser::~Parser() 
{
	m_oBuffer1.Free();
	m_oBuffer2.Free();
	delete m_pLexer;
}

Object *Parser::GetObject(Object *pObject, unsigned char *sDecryptKey, CryptAlgorithm eEncryptAlgorithm, int nKeyLength, int nObjectNum, int nObjectGen) 
{
	Stream *pStream = NULL;
	Object oTemp;
	int nNum = 0;

	// Îáíîâëÿåì áóôôåð ïîñëå Inline image data
	if ( m_nInlineImage == 2 ) 
	{
		m_oBuffer1.Free();
		m_oBuffer2.Free();
		m_pLexer->GetObject( &m_oBuffer1 );
		m_pLexer->GetObject( &m_oBuffer2 );
		m_nInlineImage = 0;
	}

	// Ìàññèâ
	if ( m_oBuffer1.IsCommand("[") ) 
	{
		Shift();
		pObject->InitArray(m_pXref);
		while ( !m_oBuffer1.IsCommand("]" ) && !m_oBuffer1.IsEOF() )
			pObject->ArrayAdd( GetObject( &oTemp, sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen) );
		if ( m_oBuffer1.IsEOF() )
		{
			// TO DO: Error "End of file inside array"
		}
		Shift();
	} 
	else if ( m_oBuffer1.IsCommand("<<") ) 	// Dictionary èëè Stream
	{
		Shift();
		pObject->InitDict(m_pXref);
		while ( !m_oBuffer1.IsCommand(">>") && !m_oBuffer1.IsEOF() ) 
		{
			if ( !m_oBuffer1.IsName() ) 
			{
				// TO DO: Error "Dictionary key must be a name object"
				Shift();
			} 
			else 
			{
				char *sKey = CopyString( m_oBuffer1.GetName() );
				Shift();
				if ( m_oBuffer1.IsEOF() || m_oBuffer1.IsError() ) 
				{
					MemUtilsFree( sKey );
					break;
				}
				pObject->DictAdd( sKey, GetObject( &oTemp, sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen));
			}
		}
		if ( m_oBuffer1.IsEOF() )
		{
			// TO DO: Error "End of file inside dictionary"
		}
		// Îáúåêòû Stream Objects íå äîïóñòèìû âíóòðè ïîòîêà èëè îáúåêòà òèïà Stream Objects
		if ( m_bAllowStreams && m_oBuffer2.IsCommand("stream") ) 
		{
			if ( ( pStream = CreateStream(pObject, sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen) ) ) 
			{
				pObject->InitStream( pStream );
			} 
			else 
			{
				pObject->Free();
				pObject->InitError();
			}
		}
		else 
		{
			Shift();
		}
	} 
	else if ( m_oBuffer1.IsInt() ) 	// Ëèáî ññûëêà, ëèáî ÷èñëî
	{
		nNum = m_oBuffer1.GetInt();
		Shift();
		if ( m_oBuffer1.IsInt() && m_oBuffer2.IsCommand("R") ) 
		{
			pObject->InitRef( nNum, m_oBuffer1.GetInt());
			Shift();
			Shift();
		} 
		else 
		{
			pObject->InitInt(nNum);
		}
	} 
	else if ( m_oBuffer1.IsString() && sDecryptKey ) // ñòðîêà
	{
		StringExt *seTemp = m_oBuffer1.GetString();
		StringExt *seRes = new StringExt();
		oTemp.InitNull();
		DecryptStream *pDecrypt = new DecryptStream(new MemoryStream( seTemp->GetBuffer(), 0, seTemp->GetLength(), &oTemp), sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen);
		pDecrypt->Reset();
		int nChar = 0;
		while ( ( nChar = pDecrypt->GetChar() ) != EOF ) 
		{
			seRes->Append((char)nChar);
		}
		delete pDecrypt;
		pObject->InitString(seRes);
		Shift();
	} 
	else // ïðîñòîé îáúåêò
	{
		m_oBuffer1.Copy(pObject);
		Shift();
	}

	return pObject;
}

Stream *Parser::CreateStream(Object *pDict, unsigned char *sDecryptKey, CryptAlgorithm eEncryptAlgorithm, int nKeyLength, int nObjectNum, int nObjectGen)
{
	Object oTemp;
	unsigned int nLength, unEndPos;

	m_pLexer->SkipToNextLine();
	unsigned int unPos = m_pLexer->GetPos();

	// Ñ÷èòûâàåì äëèíó
	pDict->DictLookup("Length", &oTemp);
	if ( oTemp.IsInt() ) 
	{
		nLength = (unsigned int)oTemp.GetInt();
		oTemp.Free();
	} 
	else 
	{
		oTemp.Free();
		unsigned int unEndPos = unPos;

		while ( !m_oBuffer2.IsCommand("endstream") && !m_oBuffer2.IsEOF() )
		{
			unEndPos = m_pLexer->GetPos();
			Shift();
		}

		nLength = unEndPos - unPos;
		m_pLexer->SetPos( unPos );

		// Îñòàâèì íà âñÿêèé ñëó÷àé çàãëóøêó
		if ( nLength <= 0 )
			nLength = 5000;
	}

	// Ìåíÿåì äëèíó, åñëè ôàéë ïîâðåæäåí
	if ( m_pXref && m_pXref->GetStreamEnd( unPos, &unEndPos) ) 
	{
		nLength = unEndPos - unPos;
	}

	// Â ñèëüíî ïîâåðæäåííûõ ôàéëàõ PDF, âûñòàâëÿåì êîíåö ïîòîêà ñðàçó
	// ïîñëå åãî íà÷àëà
	if ( !m_pLexer->GetStream() ) 
	{
		return NULL;
	}
	
	BaseStream *pBaseStream = m_pLexer->GetStream()->GetBaseStream();

	// Ïðîïóñêàåì äàííûé ïîòîêà
	m_pLexer->SetPos( unPos + nLength );

	// Ïðîâåðÿåì 'endstream'
	Shift();  // '>>'
	Shift();  // 'endstream'
	if ( m_oBuffer1.IsCommand("endstream") ) 
	{
		Shift();
	} 
	else 
	{
		// TO DO : Error "Missing 'endstream'"

		// Çàïëàòêà äëÿ ïîâðåæäåííûõ ôàéëîâ: 
		nLength += 5000;
	}

	Stream *pStream = pBaseStream->MakeSubStream( unPos, TRUE, nLength, pDict );

	// Decryption
	if ( sDecryptKey ) 
	{
		pStream = new DecryptStream( pStream, sDecryptKey, eEncryptAlgorithm, nKeyLength, nObjectNum, nObjectGen);
	}

	// Filters
	pStream = pStream->AddFilters( pDict );

	return pStream;
}

void Parser::Shift() 
{
	if ( m_nInlineImage > 0 )  
	{
		if ( m_nInlineImage < 2 ) 
		{
			++m_nInlineImage;
		} 
		else 
		{
			// Â ïîâðåæäåííîì ïîòîêå, åñëè 'ID' ïîÿâëÿåòñÿ â ñåðåäèíå ïîòîêà,
			// íóæíî ñáðîñèòü ïàðàìåòðû
			m_nInlineImage = 0;
		}
	} 
	else if ( m_oBuffer2.IsCommand("ID") ) 
	{
		m_pLexer->SkipChar(); // ïðîïóñêàåì ñèìâîë ïîñëå êîìàíäû 'ID'
		m_nInlineImage = 1;
	}
	m_oBuffer1.Free();
	m_oBuffer1 = m_oBuffer2;
	if ( m_nInlineImage > 0 ) // íå áóôôåðèçèðóåì äàííûå Inline Image
		m_oBuffer2.InitNull();
	else
		m_pLexer->GetObject( &m_oBuffer2 );
}