/**************************************************************
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/


// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_package.hxx"

#include <com/sun/star/lang/XMultiServiceFactory.hpp>
#include <com/sun/star/ucb/XProgressHandler.hpp>
#include <com/sun/star/packages/zip/ZipConstants.hpp>
#include <com/sun/star/xml/crypto/XCipherContext.hpp>
#include <com/sun/star/xml/crypto/XDigestContext.hpp>
#include <com/sun/star/xml/crypto/XCipherContextSupplier.hpp>
#include <com/sun/star/xml/crypto/XDigestContextSupplier.hpp>
#include <com/sun/star/xml/crypto/CipherID.hpp>
#include <com/sun/star/xml/crypto/DigestID.hpp>

#include <comphelper/storagehelper.hxx>
#include <comphelper/processfactory.hxx>
#include <rtl/digest.h>

#include <vector>

#include "blowfishcontext.hxx"
#include "sha1context.hxx"
#include <ZipFile.hxx>
#include <ZipEnumeration.hxx>
#include <XUnbufferedStream.hxx>
#include <PackageConstants.hxx>
#include <EncryptedDataHeader.hxx>
#include <EncryptionData.hxx>
#include <MemoryByteGrabber.hxx>

#include <CRC32.hxx>

#define AES_CBC_BLOCK_SIZE 16

using namespace vos;
using namespace rtl;
using namespace com::sun::star;
using namespace com::sun::star::io;
using namespace com::sun::star::uno;
using namespace com::sun::star::ucb;
using namespace com::sun::star::lang;
using namespace com::sun::star::packages;
using namespace com::sun::star::packages::zip;
using namespace com::sun::star::packages::zip::ZipConstants;


/** This class is used to read entries from a zip file
 */
ZipFile::ZipFile( uno::Reference < XInputStream > &xInput, const uno::Reference < XMultiServiceFactory > &xNewFactory, sal_Bool bInitialise )
	throw(IOException, ZipException, RuntimeException)
: aGrabber(xInput)
, aInflater (sal_True)
, xStream(xInput)
, xSeek(xInput, UNO_QUERY)
, m_xFactory ( xNewFactory )
, bRecoveryMode( sal_False )
{
	if (bInitialise)
	{
		if ( readCEN() == -1 )
		{
			aEntries.clear();
			throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "stream data looks to be broken" ) ), uno::Reference < XInterface > () );
		}
	}
}


ZipFile::ZipFile( uno::Reference < XInputStream > &xInput, const uno::Reference < XMultiServiceFactory > &xNewFactory, sal_Bool bInitialise, sal_Bool bForceRecovery, uno::Reference < XProgressHandler > xProgress )
	throw(IOException, ZipException, RuntimeException)
: aGrabber(xInput)
, aInflater (sal_True)
, xStream(xInput)
, xSeek(xInput, UNO_QUERY)
, m_xFactory ( xNewFactory )
, xProgressHandler( xProgress )
, bRecoveryMode( bForceRecovery )
{
	if (bInitialise)
	{
		if ( bForceRecovery )
		{
			recover();
		}
		else if ( readCEN() == -1 )
		{
			aEntries.clear();
			throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "stream data looks to be broken" ) ), uno::Reference < XInterface > () );
		}
	}
}

ZipFile::~ZipFile()
{
    aEntries.clear();
}

void ZipFile::setInputStream ( uno::Reference < XInputStream > xNewStream )
{
    ::osl::MutexGuard aGuard( m_aMutex );

	xStream = xNewStream;
	xSeek = uno::Reference < XSeekable > ( xStream, UNO_QUERY );
	aGrabber.setInputStream ( xStream );
}

uno::Reference< xml::crypto::XDigestContext > ZipFile::StaticGetDigestContextForChecksum( const uno::Reference< lang::XMultiServiceFactory >& xArgFactory, const ::rtl::Reference< EncryptionData >& xEncryptionData )
{
    uno::Reference< xml::crypto::XDigestContext > xDigestContext;
    if ( xEncryptionData->m_nCheckAlg == xml::crypto::DigestID::SHA256_1K )
    {
        uno::Reference< lang::XMultiServiceFactory > xFactory = xArgFactory;
        if ( !xFactory.is() )
            xFactory.set( comphelper::getProcessServiceFactory(), uno::UNO_SET_THROW );

        uno::Reference< xml::crypto::XDigestContextSupplier > xDigestContextSupplier(
            xFactory->createInstance( rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( "com.sun.star.xml.crypto.NSSInitializer" ) ) ),
            uno::UNO_QUERY_THROW );

        xDigestContext.set( xDigestContextSupplier->getDigestContext( xEncryptionData->m_nCheckAlg, uno::Sequence< beans::NamedValue >() ), uno::UNO_SET_THROW );
    }
    else if ( xEncryptionData->m_nCheckAlg == xml::crypto::DigestID::SHA1_1K )
        xDigestContext.set( SHA1DigestContext::Create(), uno::UNO_SET_THROW );

    return xDigestContext;
}

uno::Reference< xml::crypto::XCipherContext > ZipFile::StaticGetCipher( const uno::Reference< lang::XMultiServiceFactory >& xArgFactory, const ::rtl::Reference< EncryptionData >& xEncryptionData, bool bEncrypt )
{
    uno::Reference< xml::crypto::XCipherContext > xResult;

    try
    {
        uno::Sequence< sal_Int8 > aDerivedKey( xEncryptionData->m_nDerivedKeySize );
        if ( rtl_Digest_E_None != rtl_digest_PBKDF2( reinterpret_cast< sal_uInt8* >( aDerivedKey.getArray() ),
                            aDerivedKey.getLength(),
							reinterpret_cast< const sal_uInt8 * > (xEncryptionData->m_aKey.getConstArray() ),
							xEncryptionData->m_aKey.getLength(),
							reinterpret_cast< const sal_uInt8 * > ( xEncryptionData->m_aSalt.getConstArray() ),
							xEncryptionData->m_aSalt.getLength(),
							xEncryptionData->m_nIterationCount ) )
        {
            throw ZipIOException( ::rtl::OUString::createFromAscii( "Can not create derived key!\n" ),
                                  uno::Reference< XInterface >() );
        }

        if ( xEncryptionData->m_nEncAlg == xml::crypto::CipherID::AES_CBC_W3C_PADDING )
        {
            uno::Reference< lang::XMultiServiceFactory > xFactory = xArgFactory;
            if ( !xFactory.is() )
                xFactory.set( comphelper::getProcessServiceFactory(), uno::UNO_SET_THROW );

            uno::Reference< xml::crypto::XCipherContextSupplier > xCipherContextSupplier(
                xFactory->createInstance( rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( "com.sun.star.xml.crypto.NSSInitializer" ) ) ),
                uno::UNO_QUERY_THROW );

            xResult = xCipherContextSupplier->getCipherContext( xEncryptionData->m_nEncAlg, aDerivedKey, xEncryptionData->m_aInitVector, bEncrypt, uno::Sequence< beans::NamedValue >() );
        }
        else if ( xEncryptionData->m_nEncAlg == xml::crypto::CipherID::BLOWFISH_CFB_8 )
        {
            xResult = BlowfishCFB8CipherContext::Create( aDerivedKey, xEncryptionData->m_aInitVector, bEncrypt );
        }
        else
        {
            throw ZipIOException( ::rtl::OUString::createFromAscii( "Unknown cipher algorithm is requested!\n" ),
                                  uno::Reference< XInterface >() );
        }
    }
    catch( uno::Exception& )
    {
        OSL_ENSURE( sal_False, "Can not create cipher context!" );
    }

    return xResult;
}

void ZipFile::StaticFillHeader( const ::rtl::Reference< EncryptionData >& rData, 
								sal_Int32 nSize,
								const ::rtl::OUString& aMediaType,
								sal_Int8 * & pHeader )
{
	// I think it's safe to restrict vector and salt length to 2 bytes !
	sal_Int16 nIVLength = static_cast < sal_Int16 > ( rData->m_aInitVector.getLength() );
	sal_Int16 nSaltLength = static_cast < sal_Int16 > ( rData->m_aSalt.getLength() );
	sal_Int16 nDigestLength = static_cast < sal_Int16 > ( rData->m_aDigest.getLength() );
	sal_Int16 nMediaTypeLength = static_cast < sal_Int16 > ( aMediaType.getLength() * sizeof( sal_Unicode ) );

	// First the header
	*(pHeader++) = ( n_ConstHeader >> 0 ) & 0xFF;
	*(pHeader++) = ( n_ConstHeader >> 8 ) & 0xFF;
	*(pHeader++) = ( n_ConstHeader >> 16 ) & 0xFF;
	*(pHeader++) = ( n_ConstHeader >> 24 ) & 0xFF;

	// Then the version
	*(pHeader++) = ( n_ConstCurrentVersion >> 0 ) & 0xFF;
	*(pHeader++) = ( n_ConstCurrentVersion >> 8 ) & 0xFF;

	// Then the iteration Count
	sal_Int32 nIterationCount = rData->m_nIterationCount;
	*(pHeader++) = static_cast< sal_Int8 >(( nIterationCount >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nIterationCount >> 8 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nIterationCount >> 16 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nIterationCount >> 24 ) & 0xFF);

	// Then the size
	*(pHeader++) = static_cast< sal_Int8 >(( nSize >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nSize >> 8 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nSize >> 16 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nSize >> 24 ) & 0xFF);

	// Then the encryption algorithm
    sal_Int32 nEncAlgID = rData->m_nEncAlg;
	*(pHeader++) = static_cast< sal_Int8 >(( nEncAlgID >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nEncAlgID >> 8 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nEncAlgID >> 16 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nEncAlgID >> 24 ) & 0xFF);

	// Then the checksum algorithm
    sal_Int32 nChecksumAlgID = rData->m_nCheckAlg;
	*(pHeader++) = static_cast< sal_Int8 >(( nChecksumAlgID >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nChecksumAlgID >> 8 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nChecksumAlgID >> 16 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nChecksumAlgID >> 24 ) & 0xFF);

	// Then the derived key size
    sal_Int32 nDerivedKeySize = rData->m_nDerivedKeySize;
	*(pHeader++) = static_cast< sal_Int8 >(( nDerivedKeySize >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nDerivedKeySize >> 8 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nDerivedKeySize >> 16 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nDerivedKeySize >> 24 ) & 0xFF);

	// Then the start key generation algorithm
    sal_Int32 nKeyAlgID = rData->m_nStartKeyGenID;
	*(pHeader++) = static_cast< sal_Int8 >(( nKeyAlgID >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nKeyAlgID >> 8 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nKeyAlgID >> 16 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nKeyAlgID >> 24 ) & 0xFF);

	// Then the salt length
	*(pHeader++) = static_cast< sal_Int8 >(( nSaltLength >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nSaltLength >> 8 ) & 0xFF);

	// Then the IV length
	*(pHeader++) = static_cast< sal_Int8 >(( nIVLength >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nIVLength >> 8 ) & 0xFF);

	// Then the digest length
	*(pHeader++) = static_cast< sal_Int8 >(( nDigestLength >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nDigestLength >> 8 ) & 0xFF);

	// Then the mediatype length
	*(pHeader++) = static_cast< sal_Int8 >(( nMediaTypeLength >> 0 ) & 0xFF);
	*(pHeader++) = static_cast< sal_Int8 >(( nMediaTypeLength >> 8 ) & 0xFF);

	// Then the salt content
	rtl_copyMemory ( pHeader, rData->m_aSalt.getConstArray(), nSaltLength ); 
	pHeader += nSaltLength;

	// Then the IV content
	rtl_copyMemory ( pHeader, rData->m_aInitVector.getConstArray(), nIVLength ); 
	pHeader += nIVLength;

	// Then the digest content
	rtl_copyMemory ( pHeader, rData->m_aDigest.getConstArray(), nDigestLength ); 
	pHeader += nDigestLength;

	// Then the mediatype itself
	rtl_copyMemory ( pHeader, aMediaType.getStr(), nMediaTypeLength ); 
	pHeader += nMediaTypeLength;
}

sal_Bool ZipFile::StaticFillData (  ::rtl::Reference< BaseEncryptionData > & rData,
                                    sal_Int32 &rEncAlg,
                                    sal_Int32 &rChecksumAlg,
                                    sal_Int32 &rDerivedKeySize,
                                    sal_Int32 &rStartKeyGenID,
									sal_Int32 &rSize,
									::rtl::OUString& aMediaType,
									const uno::Reference< XInputStream >& rStream )
{
	sal_Bool bOk = sal_False;
	const sal_Int32 nHeaderSize = n_ConstHeaderSize - 4;
	Sequence < sal_Int8 > aBuffer ( nHeaderSize );
	if ( nHeaderSize == rStream->readBytes ( aBuffer, nHeaderSize ) )
	{
		sal_Int16 nPos = 0;
		sal_Int8 *pBuffer = aBuffer.getArray();
		sal_Int16 nVersion = pBuffer[nPos++] & 0xFF;
		nVersion |= ( pBuffer[nPos++] & 0xFF ) << 8;
		if ( nVersion == n_ConstCurrentVersion )
		{
			sal_Int32 nCount = pBuffer[nPos++] & 0xFF;
			nCount |= ( pBuffer[nPos++] & 0xFF ) << 8;
			nCount |= ( pBuffer[nPos++] & 0xFF ) << 16;
			nCount |= ( pBuffer[nPos++] & 0xFF ) << 24;
			rData->m_nIterationCount = nCount;

			rSize  =   pBuffer[nPos++] & 0xFF;
			rSize |= ( pBuffer[nPos++] & 0xFF ) << 8;
			rSize |= ( pBuffer[nPos++] & 0xFF ) << 16;
			rSize |= ( pBuffer[nPos++] & 0xFF ) << 24;

			rEncAlg   =   pBuffer[nPos++] & 0xFF;
			rEncAlg  |= ( pBuffer[nPos++] & 0xFF ) << 8;
			rEncAlg  |= ( pBuffer[nPos++] & 0xFF ) << 16;
			rEncAlg  |= ( pBuffer[nPos++] & 0xFF ) << 24;

			rChecksumAlg   =   pBuffer[nPos++] & 0xFF;
			rChecksumAlg  |= ( pBuffer[nPos++] & 0xFF ) << 8;
			rChecksumAlg  |= ( pBuffer[nPos++] & 0xFF ) << 16;
			rChecksumAlg  |= ( pBuffer[nPos++] & 0xFF ) << 24;

			rDerivedKeySize   =   pBuffer[nPos++] & 0xFF;
			rDerivedKeySize  |= ( pBuffer[nPos++] & 0xFF ) << 8;
			rDerivedKeySize  |= ( pBuffer[nPos++] & 0xFF ) << 16;
			rDerivedKeySize  |= ( pBuffer[nPos++] & 0xFF ) << 24;

			rStartKeyGenID   =   pBuffer[nPos++] & 0xFF;
			rStartKeyGenID  |= ( pBuffer[nPos++] & 0xFF ) << 8;
			rStartKeyGenID  |= ( pBuffer[nPos++] & 0xFF ) << 16;
			rStartKeyGenID  |= ( pBuffer[nPos++] & 0xFF ) << 24;

			sal_Int16 nSaltLength =   pBuffer[nPos++] & 0xFF;
			nSaltLength          |= ( pBuffer[nPos++] & 0xFF ) << 8;
			sal_Int16 nIVLength   = ( pBuffer[nPos++] & 0xFF );
			nIVLength 			 |= ( pBuffer[nPos++] & 0xFF ) << 8;
			sal_Int16 nDigestLength = pBuffer[nPos++] & 0xFF;
			nDigestLength 	     |= ( pBuffer[nPos++] & 0xFF ) << 8;

			sal_Int16 nMediaTypeLength = pBuffer[nPos++] & 0xFF;
			nMediaTypeLength |= ( pBuffer[nPos++] & 0xFF ) << 8;

			if ( nSaltLength == rStream->readBytes ( aBuffer, nSaltLength ) )
			{
				rData->m_aSalt.realloc ( nSaltLength );
				rtl_copyMemory ( rData->m_aSalt.getArray(), aBuffer.getConstArray(), nSaltLength );
				if ( nIVLength == rStream->readBytes ( aBuffer, nIVLength ) )
				{
					rData->m_aInitVector.realloc ( nIVLength );
					rtl_copyMemory ( rData->m_aInitVector.getArray(), aBuffer.getConstArray(), nIVLength );
					if ( nDigestLength == rStream->readBytes ( aBuffer, nDigestLength ) )
					{
						rData->m_aDigest.realloc ( nDigestLength );
						rtl_copyMemory ( rData->m_aDigest.getArray(), aBuffer.getConstArray(), nDigestLength );

						if ( nMediaTypeLength == rStream->readBytes ( aBuffer, nMediaTypeLength ) )
						{
							aMediaType = ::rtl::OUString( (sal_Unicode*)aBuffer.getConstArray(),
															nMediaTypeLength / sizeof( sal_Unicode ) );
							bOk = sal_True;
						}
					}
				}
			}
		}
	}
	return bOk;
}

uno::Reference< XInputStream > ZipFile::StaticGetDataFromRawStream( const uno::Reference< lang::XMultiServiceFactory >& xFactory,
                                                                const uno::Reference< XInputStream >& xStream,
																const ::rtl::Reference< EncryptionData > &rData )
		throw ( packages::WrongPasswordException, ZipIOException, RuntimeException )
{
	if ( !rData.is() )
		throw ZipIOException( OUString::createFromAscii( "Encrypted stream without encryption data!\n" ),
							uno::Reference< XInterface >() );

	if ( !rData->m_aKey.getLength() )
		throw packages::WrongPasswordException( ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( OSL_LOG_PREFIX ) ), uno::Reference< uno::XInterface >() );

	uno::Reference< XSeekable > xSeek( xStream, UNO_QUERY );
	if ( !xSeek.is() )
		throw ZipIOException( OUString::createFromAscii( "The stream must be seekable!\n" ),
							uno::Reference< XInterface >() );


	// if we have a digest, then this file is an encrypted one and we should
	// check if we can decrypt it or not
	OSL_ENSURE( rData->m_aDigest.getLength(), "Can't detect password correctness without digest!\n" );
	if ( rData->m_aDigest.getLength() )
	{
        sal_Int32 nSize = sal::static_int_cast< sal_Int32 >( xSeek->getLength() );
        if ( nSize > n_ConstDigestLength + 32 )
            nSize = n_ConstDigestLength + 32;

		// skip header
		xSeek->seek( n_ConstHeaderSize + rData->m_aInitVector.getLength() + 
								rData->m_aSalt.getLength() + rData->m_aDigest.getLength() );

		// Only want to read enough to verify the digest
		Sequence < sal_Int8 > aReadBuffer ( nSize );

		xStream->readBytes( aReadBuffer, nSize ); 
	
		if ( !StaticHasValidPassword( xFactory, aReadBuffer, rData ) )
			throw packages::WrongPasswordException( ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( OSL_LOG_PREFIX ) ), uno::Reference< uno::XInterface >() );
	}

	return new XUnbufferedStream( xFactory, xStream, rData );
}

#if 0
// for debugging purposes
void CheckSequence( const uno::Sequence< sal_Int8 >& aSequence )
{
    if ( aSequence.getLength() )
    {
        sal_Int32* pPointer = *( (sal_Int32**)&aSequence );
        sal_Int32 nSize = *( pPointer + 1 );
        sal_Int32 nMemSize = *( pPointer - 2 );
        sal_Int32 nUsedMemSize = ( nSize + 4 * sizeof( sal_Int32 ) );
        OSL_ENSURE( nSize == aSequence.getLength() && nUsedMemSize + 7 - ( nUsedMemSize - 1 ) % 8 == nMemSize, "Broken Sequence!" );
    }
}
#endif

sal_Bool ZipFile::StaticHasValidPassword( const uno::Reference< lang::XMultiServiceFactory >& xFactory, const Sequence< sal_Int8 > &aReadBuffer, const ::rtl::Reference< EncryptionData > &rData )
{
	if ( !rData.is() || !rData->m_aKey.getLength() )
		return sal_False;

	sal_Bool bRet = sal_False;

    uno::Reference< xml::crypto::XCipherContext > xCipher( StaticGetCipher( xFactory, rData, false ), uno::UNO_SET_THROW );

    uno::Sequence< sal_Int8 > aDecryptBuffer;
    uno::Sequence< sal_Int8 > aDecryptBuffer2;
    try
    {
        aDecryptBuffer = xCipher->convertWithCipherContext( aReadBuffer );
        aDecryptBuffer2 = xCipher->finalizeCipherContextAndDispose();
    }
    catch( uno::Exception& )
    {
        // decryption with padding will throw the exception in finalizing if the buffer represent only part of the stream
        // it is no problem, actually this is why we read 32 additional bytes ( two of maximal possible encryption blocks )
    }

    if ( aDecryptBuffer2.getLength() )
    {
        sal_Int32 nOldLen = aDecryptBuffer.getLength();
        aDecryptBuffer.realloc( nOldLen + aDecryptBuffer2.getLength() );
        rtl_copyMemory( aDecryptBuffer.getArray() + nOldLen, aDecryptBuffer2.getArray(), aDecryptBuffer2.getLength() );
    }

    if ( aDecryptBuffer.getLength() > n_ConstDigestLength )
        aDecryptBuffer.realloc( n_ConstDigestLength );

    uno::Sequence< sal_Int8 > aDigestSeq;
    uno::Reference< xml::crypto::XDigestContext > xDigestContext( StaticGetDigestContextForChecksum( xFactory, rData ), uno::UNO_SET_THROW );

    xDigestContext->updateDigest( aDecryptBuffer );
    aDigestSeq = xDigestContext->finalizeDigestAndDispose();

    // If we don't have a digest, then we have to assume that the password is correct
	if (  rData->m_aDigest.getLength() != 0  && 
	      ( aDigestSeq.getLength() != rData->m_aDigest.getLength() ||
	        0 != rtl_compareMemory ( aDigestSeq.getConstArray(), 
		 					        rData->m_aDigest.getConstArray(), 
							        aDigestSeq.getLength() ) ) )
	{
		// We should probably tell the user that the password they entered was wrong
	}
	else
		bRet = sal_True;

	return bRet;
}

sal_Bool ZipFile::hasValidPassword ( ZipEntry & rEntry, const ::rtl::Reference< EncryptionData >& rData )
{
    ::osl::MutexGuard aGuard( m_aMutex );

	sal_Bool bRet = sal_False;
	if ( rData.is() && rData->m_aKey.getLength() )
	{
		xSeek->seek( rEntry.nOffset );
		sal_Int32 nSize = rEntry.nMethod == DEFLATED ? rEntry.nCompressedSize : rEntry.nSize;

		// Only want to read enough to verify the digest
        if ( nSize > n_ConstDigestDecrypt )
            nSize = n_ConstDigestDecrypt;

		Sequence < sal_Int8 > aReadBuffer ( nSize );

		xStream->readBytes( aReadBuffer, nSize ); 

		bRet = StaticHasValidPassword( m_xFactory, aReadBuffer, rData );
	}

	return bRet;
}

uno::Reference< XInputStream > ZipFile::createUnbufferedStream(
            SotMutexHolderRef aMutexHolder,
			ZipEntry & rEntry,
			const ::rtl::Reference< EncryptionData > &rData,
			sal_Int8 nStreamMode,
			sal_Bool bIsEncrypted,
			::rtl::OUString aMediaType )
{
    ::osl::MutexGuard aGuard( m_aMutex );

	return new XUnbufferedStream ( m_xFactory, aMutexHolder, rEntry, xStream, rData, nStreamMode, bIsEncrypted, aMediaType, bRecoveryMode );
}


ZipEnumeration * SAL_CALL ZipFile::entries(  )
{
	return new ZipEnumeration ( aEntries );
}

uno::Reference< XInputStream > SAL_CALL ZipFile::getInputStream( ZipEntry& rEntry,
		const ::rtl::Reference< EncryptionData > &rData,
		sal_Bool bIsEncrypted,
        SotMutexHolderRef aMutexHolder )
	throw(IOException, ZipException, RuntimeException)
{
    ::osl::MutexGuard aGuard( m_aMutex );

	if ( rEntry.nOffset <= 0 )
		readLOC( rEntry );

	// We want to return a rawStream if we either don't have a key or if the 
	// key is wrong
	
	sal_Bool bNeedRawStream = rEntry.nMethod == STORED;
	
	// if we have a digest, then this file is an encrypted one and we should
	// check if we can decrypt it or not
	if ( bIsEncrypted && rData.is() && rData->m_aDigest.getLength() )
		bNeedRawStream = !hasValidPassword ( rEntry, rData );

	return createUnbufferedStream ( aMutexHolder,
                                    rEntry,
									rData,
									bNeedRawStream ? UNBUFF_STREAM_RAW : UNBUFF_STREAM_DATA,
									bIsEncrypted );
}

uno::Reference< XInputStream > SAL_CALL ZipFile::getDataStream( ZipEntry& rEntry,
		const ::rtl::Reference< EncryptionData > &rData,
		sal_Bool bIsEncrypted,
        SotMutexHolderRef aMutexHolder )
	throw ( packages::WrongPasswordException,
			IOException,
			ZipException,
			RuntimeException )
{
    ::osl::MutexGuard aGuard( m_aMutex );

	if ( rEntry.nOffset <= 0 )
		readLOC( rEntry );

	// An exception must be thrown in case stream is encrypted and 
	// there is no key or the key is wrong
	sal_Bool bNeedRawStream = sal_False;
	if ( bIsEncrypted )
	{
		// in case no digest is provided there is no way
		// to detect password correctness
		if ( !rData.is() )
			throw ZipException( OUString::createFromAscii( "Encrypted stream without encryption data!\n" ),
								uno::Reference< XInterface >() );

		// if we have a digest, then this file is an encrypted one and we should
		// check if we can decrypt it or not
		OSL_ENSURE( rData->m_aDigest.getLength(), "Can't detect password correctness without digest!\n" );
		if ( rData->m_aDigest.getLength() && !hasValidPassword ( rEntry, rData ) )
				throw packages::WrongPasswordException( ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( OSL_LOG_PREFIX ) ), uno::Reference< uno::XInterface >() );
	}
	else
		bNeedRawStream = ( rEntry.nMethod == STORED );

	return createUnbufferedStream ( aMutexHolder,
                                    rEntry,
									rData,
									bNeedRawStream ? UNBUFF_STREAM_RAW : UNBUFF_STREAM_DATA,
									bIsEncrypted );
}

uno::Reference< XInputStream > SAL_CALL ZipFile::getRawData( ZipEntry& rEntry,
		const ::rtl::Reference< EncryptionData >& rData,
		sal_Bool bIsEncrypted,
        SotMutexHolderRef aMutexHolder )
	throw(IOException, ZipException, RuntimeException)
{
    ::osl::MutexGuard aGuard( m_aMutex );

	if ( rEntry.nOffset <= 0 )
		readLOC( rEntry );

	return createUnbufferedStream ( aMutexHolder, rEntry, rData, UNBUFF_STREAM_RAW, bIsEncrypted );
}

uno::Reference< XInputStream > SAL_CALL ZipFile::getWrappedRawStream(
		ZipEntry& rEntry,
		const ::rtl::Reference< EncryptionData >& rData,
		const ::rtl::OUString& aMediaType,
        SotMutexHolderRef aMutexHolder )
	throw ( packages::NoEncryptionException,
			IOException,
			ZipException,
			RuntimeException )
{
    ::osl::MutexGuard aGuard( m_aMutex );

	if ( !rData.is() )
		throw packages::NoEncryptionException( ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM( OSL_LOG_PREFIX ) ), uno::Reference< uno::XInterface >() );

	if ( rEntry.nOffset <= 0 )
		readLOC( rEntry );

	return createUnbufferedStream ( aMutexHolder, rEntry, rData, UNBUFF_STREAM_WRAPPEDRAW, sal_True, aMediaType );
}

sal_Bool ZipFile::readLOC( ZipEntry &rEntry )
	throw(IOException, ZipException, RuntimeException)
{
    ::osl::MutexGuard aGuard( m_aMutex );

	sal_Int32 nTestSig, nTime, nCRC, nSize, nCompressedSize;
	sal_Int16 nVersion, nFlag, nHow, nPathLen, nExtraLen;
	sal_Int32 nPos = -rEntry.nOffset;

	aGrabber.seek(nPos);
	aGrabber >> nTestSig;

	if (nTestSig != LOCSIG)
		throw ZipIOException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid LOC header (bad signature") ), uno::Reference < XInterface > () );
	aGrabber >> nVersion;
	aGrabber >> nFlag;
	aGrabber >> nHow;
	aGrabber >> nTime;
	aGrabber >> nCRC;
	aGrabber >> nCompressedSize;
	aGrabber >> nSize;
	aGrabber >> nPathLen;
	aGrabber >> nExtraLen;
	rEntry.nOffset = static_cast < sal_Int32 > (aGrabber.getPosition()) + nPathLen + nExtraLen;

    // read always in UTF8, some tools seem not to set UTF8 bit
    uno::Sequence < sal_Int8 > aNameBuffer( nPathLen );
    sal_Int32 nRead = aGrabber.readBytes( aNameBuffer, nPathLen );
    if ( nRead < aNameBuffer.getLength() )
            aNameBuffer.realloc( nRead );

    ::rtl::OUString sLOCPath = rtl::OUString::intern( (sal_Char *) aNameBuffer.getArray(), 
                                                        aNameBuffer.getLength(), 
                                                        RTL_TEXTENCODING_UTF8 );

	if ( rEntry.nPathLen == -1 ) // the file was created
    {
		rEntry.nPathLen = nPathLen;
        rEntry.sPath = sLOCPath;
    }

	// the method can be reset for internal use so it is not checked
	sal_Bool bBroken = rEntry.nVersion != nVersion
					|| rEntry.nFlag != nFlag
					|| rEntry.nTime != nTime
					|| rEntry.nPathLen != nPathLen
                    || !rEntry.sPath.equals( sLOCPath );

	if ( bBroken && !bRecoveryMode )
		throw ZipIOException( OUString( RTL_CONSTASCII_USTRINGPARAM( "The stream seems to be broken!" ) ),
							uno::Reference< XInterface >() );

	return sal_True;
}

sal_Int32 ZipFile::findEND( )
	throw(IOException, ZipException, RuntimeException)
{
    // this method is called in constructor only, no need for mutex
	sal_Int32 nLength, nPos, nEnd;
	Sequence < sal_Int8 > aBuffer;
	try
	{
		nLength = static_cast <sal_Int32 > (aGrabber.getLength());
		if (nLength == 0 || nLength < ENDHDR)
			return -1;
		nPos = nLength - ENDHDR - ZIP_MAXNAMELEN;
		nEnd = nPos >= 0 ? nPos : 0 ;

		aGrabber.seek( nEnd );
		aGrabber.readBytes ( aBuffer, nLength - nEnd );

		const sal_Int8 *pBuffer = aBuffer.getConstArray();

		nPos = nLength - nEnd - ENDHDR;
		while ( nPos >= 0 )
		{
			if (pBuffer[nPos] == 'P' && pBuffer[nPos+1] == 'K' && pBuffer[nPos+2] == 5 && pBuffer[nPos+3] == 6 )
				return nPos + nEnd;
			nPos--;
		}
	}
	catch ( IllegalArgumentException& )
	{
		throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), uno::Reference < XInterface > () );
	}
	catch ( NotConnectedException& )
	{
		throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), uno::Reference < XInterface > () );
	}
	catch ( BufferSizeExceededException& )
	{
		throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), uno::Reference < XInterface > () );
	}
	throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), uno::Reference < XInterface > () );
}

sal_Int32 ZipFile::readCEN()
	throw(IOException, ZipException, RuntimeException)
{
    // this method is called in constructor only, no need for mutex
	sal_Int32 nCenLen, nCenPos = -1, nCenOff, nEndPos, nLocPos;
	sal_uInt16 nCount, nTotal;

	try
	{
		nEndPos = findEND();
		if (nEndPos == -1)
			return -1;
		aGrabber.seek(nEndPos + ENDTOT);
		aGrabber >> nTotal;
		aGrabber >> nCenLen;
		aGrabber >> nCenOff;

		if ( nTotal * CENHDR > nCenLen )
			throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "invalid END header (bad entry count)") ), uno::Reference < XInterface > () );

		if ( nTotal > ZIP_MAXENTRIES )
			throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "too many entries in ZIP File") ), uno::Reference < XInterface > () );

		if ( nCenLen < 0 || nCenLen > nEndPos )
			throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid END header (bad central directory size)") ), uno::Reference < XInterface > () );

		nCenPos = nEndPos - nCenLen;

		if ( nCenOff < 0 || nCenOff > nCenPos )
			throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid END header (bad central directory size)") ), uno::Reference < XInterface > () );

		nLocPos = nCenPos - nCenOff;
		aGrabber.seek( nCenPos );
		Sequence < sal_Int8 > aCENBuffer ( nCenLen );
		sal_Int64 nRead = aGrabber.readBytes ( aCENBuffer, nCenLen );
		if ( static_cast < sal_Int64 > ( nCenLen ) != nRead )
			throw ZipException ( OUString ( RTL_CONSTASCII_USTRINGPARAM ( "Error reading CEN into memory buffer!") ), uno::Reference < XInterface > () );

		MemoryByteGrabber aMemGrabber ( aCENBuffer );

		ZipEntry aEntry;
		sal_Int32 nTestSig;
		sal_Int16 nCommentLen;

		for (nCount = 0 ; nCount < nTotal; nCount++)
		{
			aMemGrabber >> nTestSig;
			if ( nTestSig != CENSIG )
				throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid CEN header (bad signature)") ), uno::Reference < XInterface > () );

			aMemGrabber.skipBytes ( 2 );
			aMemGrabber >> aEntry.nVersion;

			if ( ( aEntry.nVersion & 1 ) == 1 )
				throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid CEN header (encrypted entry)") ), uno::Reference < XInterface > () );

			aMemGrabber >> aEntry.nFlag;
			aMemGrabber >> aEntry.nMethod;

			if ( aEntry.nMethod != STORED && aEntry.nMethod != DEFLATED)
				throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid CEN header (bad compression method)") ), uno::Reference < XInterface > () );

			aMemGrabber >> aEntry.nTime;
			aMemGrabber >> aEntry.nCrc;
			aMemGrabber >> aEntry.nCompressedSize;
			aMemGrabber >> aEntry.nSize;
			aMemGrabber >> aEntry.nPathLen;
			aMemGrabber >> aEntry.nExtraLen;
			aMemGrabber >> nCommentLen;
			aMemGrabber.skipBytes ( 8 );
			aMemGrabber >> aEntry.nOffset;

			aEntry.nOffset += nLocPos;
			aEntry.nOffset *= -1;

			if ( aEntry.nPathLen < 0 )
				throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "unexpected name length" ) ), uno::Reference < XInterface > () );

			if ( nCommentLen < 0 )
				throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "unexpected comment length" ) ), uno::Reference < XInterface > () );

			if ( aEntry.nExtraLen < 0 )
				throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "unexpected extra header info length") ), uno::Reference < XInterface > () );

            // read always in UTF8, some tools seem not to set UTF8 bit
			aEntry.sPath = rtl::OUString::intern ( (sal_Char *) aMemGrabber.getCurrentPos(), 
                                                   aEntry.nPathLen, 
                                                   RTL_TEXTENCODING_UTF8 );

            if ( !::comphelper::OStorageHelper::IsValidZipEntryFileName( aEntry.sPath, sal_True ) )
				throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip entry has an invalid name.") ), uno::Reference < XInterface > () );

			aMemGrabber.skipBytes( aEntry.nPathLen + aEntry.nExtraLen + nCommentLen );
			aEntries[aEntry.sPath] = aEntry;	
		}

		if (nCount != nTotal)
			throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Count != Total") ), uno::Reference < XInterface > () );
	}
	catch ( IllegalArgumentException & )
	{
		// seek can throw this...
		nCenPos = -1; // make sure we return -1 to indicate an error
	}
	return nCenPos;
}

sal_Int32 ZipFile::recover()
	throw(IOException, ZipException, RuntimeException)
{
    ::osl::MutexGuard aGuard( m_aMutex );

	sal_Int32 nLength;
	Sequence < sal_Int8 > aBuffer;
	Sequence < sal_Int32 > aHeaderOffsets;

	try
	{
		nLength = static_cast <sal_Int32 > (aGrabber.getLength());
		if (nLength == 0 || nLength < ENDHDR)
			return -1;

		aGrabber.seek( 0 );

		const sal_Int32 nToRead = 32000;
        for( sal_Int32 nGenPos = 0; aGrabber.readBytes( aBuffer, nToRead ) && aBuffer.getLength() > 16; )
        {
            const sal_Int8 *pBuffer = aBuffer.getConstArray();
            sal_Int32 nBufSize = aBuffer.getLength();

            sal_Int32 nPos = 0;
            // the buffer should contain at least one header,
            // or if it is end of the file, at least the postheader with sizes and hash
            while( nPos < nBufSize - 30
                || ( aBuffer.getLength() < nToRead && nPos < nBufSize - 16 ) )

			{
				if ( nPos < nBufSize - 30 && pBuffer[nPos] == 'P' && pBuffer[nPos+1] == 'K' && pBuffer[nPos+2] == 3 && pBuffer[nPos+3] == 4 )
				{
					ZipEntry aEntry;
					MemoryByteGrabber aMemGrabber ( Sequence< sal_Int8 >( ((sal_Int8*)(&(pBuffer[nPos+4]))), 26 ) );

					aMemGrabber >> aEntry.nVersion;
					if ( ( aEntry.nVersion & 1 ) != 1 )
					{
						aMemGrabber >> aEntry.nFlag;
						aMemGrabber >> aEntry.nMethod;

						if ( aEntry.nMethod == STORED || aEntry.nMethod == DEFLATED )
						{
							aMemGrabber >> aEntry.nTime;
							aMemGrabber >> aEntry.nCrc;
							aMemGrabber >> aEntry.nCompressedSize;
							aMemGrabber >> aEntry.nSize;
							aMemGrabber >> aEntry.nPathLen;
							aMemGrabber >> aEntry.nExtraLen;

							sal_Int32 nDescrLength = 
								( aEntry.nMethod == DEFLATED && ( aEntry.nFlag & 8 ) ) ?
														16 : 0;


							// This is a quick fix for OOo1.1RC
							// For OOo2.0 the whole package must be switched to unsigned values
							if ( aEntry.nCompressedSize < 0 ) aEntry.nCompressedSize = 0x7FFFFFFF;
							if ( aEntry.nSize < 0 ) aEntry.nSize = 0x7FFFFFFF;
							if ( aEntry.nPathLen < 0 ) aEntry.nPathLen = 0x7FFF;
							if ( aEntry.nExtraLen < 0 ) aEntry.nExtraLen = 0x7FFF;
							// End of quick fix

							sal_Int32 nDataSize = ( aEntry.nMethod == DEFLATED ) ? aEntry.nCompressedSize : aEntry.nSize;
							sal_Int32 nBlockLength = nDataSize + aEntry.nPathLen + aEntry.nExtraLen + 30 + nDescrLength;
							if ( aEntry.nPathLen >= 0 && aEntry.nExtraLen >= 0
								&& ( nGenPos + nPos + nBlockLength ) <= nLength )
							{
                                // read always in UTF8, some tools seem not to set UTF8 bit
								if( nPos + 30 + aEntry.nPathLen <= nBufSize )
									aEntry.sPath = OUString ( (sal_Char *) &pBuffer[nPos + 30], 
									  							aEntry.nPathLen, 
																RTL_TEXTENCODING_UTF8 );
								else
								{
									Sequence < sal_Int8 > aFileName;
									aGrabber.seek( nGenPos + nPos + 30 );
									aGrabber.readBytes( aFileName, aEntry.nPathLen );
									aEntry.sPath = OUString ( (sal_Char *) aFileName.getArray(), 
																aFileName.getLength(), 
																RTL_TEXTENCODING_UTF8 );
									aEntry.nPathLen = static_cast< sal_Int16 >(aFileName.getLength());
								}

								aEntry.nOffset = nGenPos + nPos + 30 + aEntry.nPathLen + aEntry.nExtraLen;

								if ( ( aEntry.nSize || aEntry.nCompressedSize ) && !checkSizeAndCRC( aEntry ) )
								{
									aEntry.nCrc = 0;
									aEntry.nCompressedSize = 0;
									aEntry.nSize = 0;
								}

								if ( aEntries.find( aEntry.sPath ) == aEntries.end() )
									aEntries[aEntry.sPath] = aEntry;
							}
						}
					}

					nPos += 4;
				}
				else if (pBuffer[nPos] == 'P' && pBuffer[nPos+1] == 'K' && pBuffer[nPos+2] == 7 && pBuffer[nPos+3] == 8 )
				{
					sal_Int32 nCompressedSize, nSize, nCRC32;
					MemoryByteGrabber aMemGrabber ( Sequence< sal_Int8 >( ((sal_Int8*)(&(pBuffer[nPos+4]))), 12 ) );
					aMemGrabber >> nCRC32;
					aMemGrabber >> nCompressedSize;
					aMemGrabber >> nSize;

					for( EntryHash::iterator aIter = aEntries.begin(); aIter != aEntries.end(); aIter++ )
					{
						ZipEntry aTmp = (*aIter).second;

                        // this is a broken package, accept this block not only for DEFLATED streams
						if( (*aIter).second.nFlag & 8 )
						{
							sal_Int32 nStreamOffset = nGenPos + nPos - nCompressedSize;
							if ( nStreamOffset == (*aIter).second.nOffset && nCompressedSize > (*aIter).second.nCompressedSize )
							{
                                // only DEFLATED blocks need to be checked
                                sal_Bool bAcceptBlock = ( (*aIter).second.nMethod == STORED && nCompressedSize == nSize );

                                if ( !bAcceptBlock )
                                {
                                    sal_Int32 nRealSize = 0, nRealCRC = 0;
                                    getSizeAndCRC( nStreamOffset, nCompressedSize, &nRealSize, &nRealCRC );
                                    bAcceptBlock = ( nRealSize == nSize && nRealCRC == nCRC32 );
                                }

                                if ( bAcceptBlock )
								{
									(*aIter).second.nCrc = nCRC32;
									(*aIter).second.nCompressedSize = nCompressedSize;
									(*aIter).second.nSize = nSize;
								}
							}
#if 0
// for now ignore clearly broken streams
							else if( !(*aIter).second.nCompressedSize )
							{
								(*aIter).second.nCrc = nCRC32;
								sal_Int32 nRealStreamSize = nGenPos + nPos - (*aIter).second.nOffset;
								(*aIter).second.nCompressedSize = nGenPos + nPos - (*aIter).second.nOffset;
								(*aIter).second.nSize = nSize;
							}
#endif
						}
					}

					nPos += 4;
				}
				else
					nPos++;
			}

			nGenPos += nPos;
			aGrabber.seek( nGenPos );
		}

		return 0;
	}
	catch ( IllegalArgumentException& )
	{
		throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), uno::Reference < XInterface > () );
	}
	catch ( NotConnectedException& )
	{
		throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), uno::Reference < XInterface > () );
	}
	catch ( BufferSizeExceededException& )
	{
		throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), uno::Reference < XInterface > () );
	}
}

sal_Bool ZipFile::checkSizeAndCRC( const ZipEntry& aEntry )
{
    ::osl::MutexGuard aGuard( m_aMutex );

	sal_Int32 nSize = 0, nCRC = 0;

	if( aEntry.nMethod == STORED )
		return ( getCRC( aEntry.nOffset, aEntry.nSize ) == aEntry.nCrc );

	getSizeAndCRC( aEntry.nOffset, aEntry.nCompressedSize, &nSize, &nCRC );
	return ( aEntry.nSize == nSize && aEntry.nCrc == nCRC );
}

sal_Int32 ZipFile::getCRC( sal_Int32 nOffset, sal_Int32 nSize )
{
    ::osl::MutexGuard aGuard( m_aMutex );

	Sequence < sal_Int8 > aBuffer;
	CRC32 aCRC;
	sal_Int32 nBlockSize = ::std::min( nSize, static_cast< sal_Int32 >( 32000 ) );

	aGrabber.seek( nOffset );
	for ( int ind = 0;
		  aGrabber.readBytes( aBuffer, nBlockSize ) && ind * nBlockSize < nSize;
		  ind++ )
	{
		aCRC.updateSegment( aBuffer, 0, ::std::min( nBlockSize, nSize - ind * nBlockSize ) );
	}

	return aCRC.getValue();
}

void ZipFile::getSizeAndCRC( sal_Int32 nOffset, sal_Int32 nCompressedSize, sal_Int32 *nSize, sal_Int32 *nCRC )
{
    ::osl::MutexGuard aGuard( m_aMutex );

	Sequence < sal_Int8 > aBuffer;
	CRC32 aCRC;
	sal_Int32 nRealSize = 0;
	Inflater aInflaterLocal( sal_True );
	sal_Int32 nBlockSize = ::std::min( nCompressedSize, static_cast< sal_Int32 >( 32000 ) );

	aGrabber.seek( nOffset );
	for ( int ind = 0;
		  !aInflaterLocal.finished() && aGrabber.readBytes( aBuffer, nBlockSize ) && ind * nBlockSize < nCompressedSize;
		  ind++ )
	{
		Sequence < sal_Int8 > aData( nBlockSize );
		sal_Int32 nLastInflated = 0;
		sal_Int32 nInBlock = 0;

		aInflaterLocal.setInput( aBuffer );
		do
		{
			nLastInflated = aInflaterLocal.doInflateSegment( aData, 0, nBlockSize );
			aCRC.updateSegment( aData, 0, nLastInflated );
			nInBlock += nLastInflated;
		} while( !aInflater.finished() && nLastInflated );
		
		nRealSize += nInBlock;
	}

    *nSize = nRealSize;
    *nCRC = aCRC.getValue();
}