libreoffice/package/source/zipapi/ZipFile.cxx

/*************************************************************************
 *
 *  $RCSfile: ZipFile.cxx,v $
 *
 *  $Revision: 1.29 $
 *
 *  last change: $Author: mtg $ $Date: 2001-08-08 18:23:04 $
 *
 *  The Contents of this file are made available subject to the terms of
 *  either of the following licenses
 *
 *         - GNU Lesser General Public License Version 2.1
 *         - Sun Industry Standards Source License Version 1.1
 *
 *  Sun Microsystems Inc., October, 2000
 *
 *  GNU Lesser General Public License Version 2.1
 *  =============================================
 *  Copyright 2000 by Sun Microsystems, Inc.
 *  901 San Antonio Road, Palo Alto, CA 94303, USA
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License version 2.1, as published by the Free Software Foundation.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *  MA  02111-1307  USA
 *
 *
 *  Sun Industry Standards Source License Version 1.1
 *  =================================================
 *  The contents of this file are subject to the Sun Industry Standards
 *  Source License Version 1.1 (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.openoffice.org/license.html.
 *
 *  Software provided under this License is provided on an "AS IS" basis,
 *  WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
 *  WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS,
 *  MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING.
 *  See the License for the specific provisions governing your rights and
 *  obligations concerning the Software.
 *
 *  The Initial Developer of the Original Code is: Sun Microsystems, Inc.
 *
 *  Copyright: 2000 by Sun Microsystems, Inc.
 *
 *  All Rights Reserved.
 *
 *  Contributor(s): Martin Gallwey (gallwey@sun.com)
 *
 *
 ************************************************************************/
#ifndef _ZIP_FILE_HXX
#include <ZipFile.hxx>
#endif
#ifndef _ENTRY_INPUT_STREAM_HXX
#include <EntryInputStream.hxx>
#endif
#ifndef _ZIP_ENUMERATION_HXX
#include <ZipEnumeration.hxx>
#endif
#ifndef _VOS_DIAGNOSE_H_
#include <vos/diagnose.hxx>
#endif
#ifndef _COM_SUN_STAR_PACKAGES_ZIP_ZIPCONSTANTS_HPP_
#include <com/sun/star/packages/zip/ZipConstants.hpp>
#endif
#ifndef _RTL_CIPHER_H_
#include <rtl/cipher.h>
#endif
#ifndef _RTL_DIGEST_H_
#include <rtl/digest.h>
#endif
#ifndef _XMEMORY_STREAM_HXX
#include <XMemoryStream.hxx>
#endif
#ifndef _XFILE_STREAM_HXX
#include <XFileStream.hxx>
#endif
#ifndef _PACKAGE_CONSTANTS_HXX_
#include <PackageConstants.hxx>
#endif
#ifndef _UCBHELPER_CONTENTBROKER_HXX
#include <ucbhelper/contentbroker.hxx>
#endif
#ifndef _RTL_USTRBUF_HXX_
#include <rtl/ustrbuf.hxx>
#endif
#ifndef UCBHELPER_FILEIDENTIFIERCONVERTER_HXX_
#include <ucbhelper/fileidentifierconverter.hxx>
#endif
#ifndef _OSL_FILE_HXX_
#include <osl/file.hxx>
#endif
#include <string.h> // for memcpy
#include <vector>

using namespace vos;
using namespace ucb;
using namespace osl;
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;

static OUString aTempNameBase_Impl;

void Impl_GetCipher ( const ORef < EncryptionData > & xEncryptionData, rtlCipher &rCipher )
{
    Sequence < sal_uInt8 > aDerivedKey (16);
    rtlCipherError aResult;
    Sequence < sal_Int8 > aDecryptBuffer;

    // Get the key
    rtl_digest_PBKDF2 ( aDerivedKey.getArray(), 16,
                        reinterpret_cast < const sal_uInt8 * > (xEncryptionData->aKey.getConstArray()),
                        xEncryptionData->aKey.getLength(),
                        xEncryptionData->aSalt.getConstArray(),
                        xEncryptionData->aSalt.getLength(),
                        xEncryptionData->nIterationCount );

    rCipher = rtl_cipher_create (rtl_Cipher_AlgorithmBF, rtl_Cipher_ModeStream);
    aResult = rtl_cipher_init( rCipher, rtl_Cipher_DirectionDecode,
                               aDerivedKey.getConstArray(),
                               aDerivedKey.getLength(),
                               xEncryptionData->aInitVector.getConstArray(),
                               xEncryptionData->aInitVector.getLength());
    OSL_ASSERT (aResult == rtl_Cipher_E_None);
}

OUString Impl_GetTempNameBaseDirectory()
{
    if (!aTempNameBase_Impl.getLength() )
        return OUString ();
    OUString aTmp;
    FileBase::getSystemPathFromFileURL( aTempNameBase_Impl, aTmp );
    return aTmp;
}

#define TMPNAME_SIZE  ( 1 + 5 + 5 + 4 + 1 )
OUString Impl_ConstructTempDir( const OUString* pParent )
{
    OUString aName;
    if ( pParent && pParent->getLength() )
    {
        ContentBroker* pBroker = ContentBroker::get();
        if ( pBroker )
        {
            Reference< XContentProviderManager > xManager =
                    pBroker->getContentProviderManagerInterface();

            // if parent given try to use it
            OUString aTmp( *pParent );

            // test for valid filename
            OUString aRet;
            FileBase::getFileURLFromSystemPath( getSystemPathFromFileURL( xManager, aTmp ), aRet );
            if ( aRet.getLength() )
            {
                DirectoryItem aItem;
                sal_Int32 i = aRet.getLength();
                if ( aRet[i-1] == '/' )
                    i--;

                if ( DirectoryItem::get( OUString( aRet, i ), aItem ) == FileBase::E_None )
                    aName = aRet;
            }
        }
        else
        {
            VOS_ENSURE( sal_False, "::unotools::TempFile : UCB not present or not initialized!" );
        }
    }

#if 1
    if ( !aName.getLength() )
    {
        // if no parent or invalid parent : use system directory
        if ( !aTempNameBase_Impl.getLength() )
            aTempNameBase_Impl = Impl_GetTempNameBaseDirectory();
        aName = aTempNameBase_Impl;
    }
#else
    if ( !aName.getLength() )
    {
        // if no parent or invalid parent : use default directory
        VOS_ENSURE( aTempNameBase_Impl.getLength(), "No TempDir!" );
        aName = aTempNameBase_Impl;
    }
#endif

    // Make sure that directory ends with a separator
    sal_Int32 i = aName.getLength();
    if( aName.lastIndexOf ('/' != i ) )
        aName += OUString( RTL_CONSTASCII_USTRINGPARAM ( "/" ) );

    return aName;
}

void Impl_CreateTempName ( OUString& rName, sal_Bool bKeep, sal_Bool bDir = sal_True )
{
    // add a suitable tempname
    // Prefix can have 5 chars, leaving 3 for numbers. 26 ** 3 == 17576
    // ER 13.07.00  why not radix 36 [0-9A-Z] ?!?
    const sal_uInt32 nRadix = 26;
    OUString aName( rName );
    TimeValue aTimeValue;
    osl_getSystemTime ( &aTimeValue );

    aName += OUString::createFromAscii( "sv" );
    rName = OUString();

    sal_uInt32 nSeed = aTimeValue.Nanosec;
    for ( unsigned long nOld = nSeed; ++nSeed != nOld; )
    {
        nSeed %= (nRadix*nRadix*nRadix);
        OUStringBuffer aBuffer;
        aBuffer.append ( aName );
        aBuffer.append ( static_cast < sal_Int32 > (nSeed), nRadix );
        aBuffer.appendAscii ( ".tmp" );

        OUString aTmp( aBuffer.makeStringAndClear() );

        if ( bDir )
        {
            FileBase::RC err = Directory::create( aTmp );
            if (  err == FileBase::E_None )
            {
                // !bKeep: only for creating a name, not a file or directory
                if ( bKeep || Directory::remove( aTmp ) == FileBase::E_None )
                    rName = aTmp;
                break;
            }
            else if ( err != FileBase::E_EXIST )
            {
                // if f.e. name contains invalid chars stop trying to create dirs
                break;
            }
        }
        else
        {
            VOS_ENSURE ( bKeep, "Too expensive, use directory for creating name!" );
            File aFile( aTmp );
            FileBase::RC err = aFile.open(osl_File_OpenFlag_Create);
            if (  err == FileBase::E_None )
            {
                rName = aTmp;
                aFile.close();
                break;
            }
            else if ( err != FileBase::E_EXIST )
            {
                 // if f.e. name contains invalid chars stop trying to create files
                 break;
            }
        }
    }
}
Reference < XInputStream > ZipFile::createFileStream(
            ZipEntry & rEntry,
            const ORef < EncryptionData > &rData,
            sal_Bool bRawStream,
            sal_Int32 nUncompressedSize,
            sal_Int32 nEnd)
{
    Sequence < sal_Int8 > aDecryptBuffer, aReadBuffer ( n_ConstBufferSize ), aWriteBuffer ( n_ConstBufferSize );
    xSeek->seek(rEntry.nOffset);

    sal_Int32 nRead = 0, nSize = rEntry.nMethod == DEFLATED ? rEntry.nCompressedSize : rEntry.nSize;
    sal_uInt64 nWritten = 0;
    rtlCipher aCipher;
    sal_Bool bMustDecrypt = rData->aSalt.getLength() ? sal_True : sal_False;

    if (nSize <0)
        throw IOException();

    OUString sTempFileName = Impl_ConstructTempDir( NULL );
    Impl_CreateTempName ( sTempFileName, sal_False );
    // Convert to File URL
    OUString sFileName;
    if ( sTempFileName.getLength() )
    {
        FileBase::getSystemPathFromFileURL( sTempFileName, sFileName );
    }

    if ( bMustDecrypt )
    {
        Impl_GetCipher ( rData, aCipher );
        aDecryptBuffer.realloc ( n_ConstBufferSize );
    }
    File *pFile = new File ( sFileName );
    pFile->open( osl_File_OpenFlag_Write );

    do
    {
        nRead = xStream->readBytes( aReadBuffer, n_ConstBufferSize ); // Now it holds the raw stuff from disk

        if ( bMustDecrypt )
        {
            rtlCipherError aResult = rtl_cipher_decode ( aCipher,
                                          aReadBuffer.getConstArray(),
                                          nRead,
                                          reinterpret_cast < sal_uInt8 * > (aDecryptBuffer.getArray()),
                                          nRead);
            OSL_ASSERT (aResult == rtl_Cipher_E_None);
        }

        if (!bRawStream && rEntry.nMethod != STORED)
        {
            aInflater.setInputSegment( bMustDecrypt ? aDecryptBuffer : aReadBuffer, 0, nRead );
            sal_Int32 nNewBytes = aInflater.doInflate( aWriteBuffer );
            pFile->write ( aWriteBuffer.getConstArray(), nNewBytes, nWritten );
        }
        else
            pFile->write ( aReadBuffer.getConstArray(), nRead, nWritten );
    }
    while (nRead == n_ConstBufferSize );

    if (!bRawStream && rEntry.nMethod != STORED )
    {
        sal_Int32 nNewBytes;
        while (!aInflater.finished())
        {
            nNewBytes = aInflater.doInflate ( aWriteBuffer );
            pFile->write ( aWriteBuffer.getConstArray(), nNewBytes, nWritten );
        }
        aInflater.reset();
    }
    pFile->close();
    return Reference < XInputStream > ( new XFileStream ( pFile ) );
}

Reference < XInputStream > ZipFile::createMemoryStream(
            ZipEntry & rEntry,
            const ORef < EncryptionData > &rData,
            sal_Bool bRawStream,
            sal_Int32 nUncompressedSize,
            sal_Int32 nEnd)
{
    xSeek->seek(rEntry.nOffset);
    sal_Int32 nSize = rEntry.nMethod == DEFLATED ? rEntry.nCompressedSize : rEntry.nSize;
    Sequence < sal_Int8 > aReadBuffer ( nSize ), aDecryptBuffer, aWriteBuffer;
    rtlCipher aCipher;
    sal_Bool bMustDecrypt = rData->aSalt.getLength() ? sal_True : sal_False;

    if ( bMustDecrypt )
    {
        Impl_GetCipher ( rData, aCipher );
        aDecryptBuffer.realloc ( nSize );
    }

    if (nSize <0)
        throw IOException ( );

    xStream->readBytes( aReadBuffer, nSize ); // Now it holds the raw stuff from disk

    if ( bMustDecrypt )
    {
        rtlCipherError aResult = rtl_cipher_decode ( aCipher,
                                      aReadBuffer.getConstArray(),
                                      nSize,
                                      reinterpret_cast < sal_uInt8 * > (aDecryptBuffer.getArray()),
                                      nSize);
        OSL_ASSERT (aResult == rtl_Cipher_E_None);
        aReadBuffer = aDecryptBuffer; // Now it holds the decrypted data
    }
    if (bRawStream || rEntry.nMethod == STORED)
        aWriteBuffer = aReadBuffer; // bRawStream means the caller doesn't want it decompressed
    else
    {
        aInflater.setInputSegment(aReadBuffer, 0, nSize );
        aWriteBuffer.realloc( nUncompressedSize );
        aInflater.doInflate( aWriteBuffer );
        aInflater.reset();
    }
    return Reference < XInputStream > ( new XMemoryStream ( aWriteBuffer ) );
}

/** This class is used to read entries from a zip file
 */
ZipFile::ZipFile( Reference < XInputStream > &xInput, sal_Bool bInitialise)
    throw(IOException, ZipException, RuntimeException)
: xStream(xInput)
, xSeek(xInput, UNO_QUERY)
, aGrabber(xInput)
, aInflater (sal_True)
, bSpanned ( sal_False )
{
    if (bInitialise)
    {
        if ( readCEN() == -1 )
            aEntries.clear();
    }
}

ZipFile::ZipFile( Reference < XInputStream > &xInput, OUString &rURL)
    throw(IOException, ZipException, RuntimeException)
: xStream(xInput)
, xSeek(xInput, UNO_QUERY)
, aGrabber(xInput)
, aInflater (sal_True)
, sURL ( rURL )
, bSpanned ( sal_True )
{
    if ( readCEN() == -1 )
        aEntries.clear();
}

void ZipFile::setInputStream ( Reference < XInputStream > xNewStream )
{
    xStream = xNewStream;
    xSeek = Reference < XSeekable > ( xStream, UNO_QUERY );
    aGrabber.setInputStream ( xStream );
}

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

void SAL_CALL ZipFile::close(  )
    throw(IOException, RuntimeException)
{
}

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

::rtl::OUString SAL_CALL ZipFile::getName(  )
    throw(RuntimeException)
{
    return sName;
}

sal_Int32 SAL_CALL ZipFile::getSize(  )
    throw(RuntimeException)
{
    return aEntries.size();
}

Type SAL_CALL ZipFile::getElementType(  )
    throw(RuntimeException)
{
    return ::getCppuType((ZipEntry *) 0);
}

sal_Bool SAL_CALL ZipFile::hasElements(  )
    throw(RuntimeException)
{
    return (aEntries.size()>0);
}

Any SAL_CALL ZipFile::getByName( const ::rtl::OUString& aName )
        throw(container::NoSuchElementException, lang::WrappedTargetException, RuntimeException)
{
    Any aAny;
    EntryHash::const_iterator aCI = aEntries.find(sName);
    if (aCI == aEntries.end())
        throw container::NoSuchElementException();
    aAny <<= (*aCI).second;
     return aAny;
}

Sequence< ::rtl::OUString > SAL_CALL ZipFile::getElementNames(  )
        throw(RuntimeException)
{
    sal_uInt32 i=0, nSize = aEntries.size();
    OUString *pNames = new OUString[aEntries.size()];
    for ( EntryHash::const_iterator aIterator = aEntries.begin(), aEnd = aEntries.end();
          aIterator != aEnd;
          aIterator++,i++)
        pNames[i] = (*aIterator).first;
    return Sequence<OUString> (pNames, nSize);
}

sal_Bool SAL_CALL ZipFile::hasByName( const ::rtl::OUString& aName )
        throw(RuntimeException)
{
    return aEntries.find(aName) != aEntries.end();
}

Reference< XInputStream > SAL_CALL ZipFile::getInputStream( ZipEntry& rEntry,
        const vos::ORef < EncryptionData > &rData)
    throw(IOException, ZipException, RuntimeException)
{
    if (rEntry.nOffset <= 0)
        readLOC(rEntry);
    //Reference< XInputStream > xStreamRef = new EntryInputStream(xStream, rEntry, rData, sal_False );

    sal_Int32 nUncompressedSize = rEntry.nSize;
    sal_Int32 nEnd = rEntry.nMethod == DEFLATED ? rEntry.nOffset + rEntry.nCompressedSize : rEntry.nOffset + rEntry.nSize;

/*
    return nUncompressedSize > n_ConstMaxMemoryStreamSize ?
               createFileStream(rEntry, rData, sal_False, nUncompressedSize, nEnd) :
               createMemoryStream(rEntry, rData, sal_False, nUncompressedSize, nEnd);
*/
    return createMemoryStream(rEntry, rData, sal_False, nUncompressedSize, nEnd);

}

Reference< XInputStream > SAL_CALL ZipFile::getRawStream( ZipEntry& rEntry,
        const vos::ORef < EncryptionData > &rData)
    throw(IOException, ZipException, RuntimeException)
{
    if (rEntry.nOffset <= 0)
        readLOC(rEntry);

    sal_Int32 nUncompressedSize = rEntry.nMethod == DEFLATED ? rEntry.nCompressedSize : rEntry.nSize;
    sal_Int32 nEnd = rEntry.nOffset + nUncompressedSize;

/*
    return nUncompressedSize > n_ConstMaxMemoryStreamSize ?
               createFileStream(rEntry, rData, sal_True, nUncompressedSize, nEnd) :
               createMemoryStream(rEntry, rData, sal_True, nUncompressedSize, nEnd);
*/
    return createMemoryStream(rEntry, rData, sal_True, nUncompressedSize, nEnd);
}

sal_Bool ZipFile::readLOC( ZipEntry &rEntry )
    throw(IOException, ZipException, RuntimeException)
{
    sal_uInt32 nTestSig, nTime, nCRC, nSize, nCompressedSize;
    sal_uInt16 nVersion, nFlag, nHow, nNameLen, nExtraLen;
    sal_Int32 nPos = -rEntry.nOffset;

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

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

sal_Int32 ZipFile::findEND( )
    throw(IOException, ZipException, RuntimeException)
{
    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!") ), Reference < XInterface> () );
    }
    catch ( NotConnectedException& )
    {
        throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), Reference < XInterface> () );
    }
    catch ( BufferSizeExceededException& )
    {
        throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), Reference < XInterface> () );
    }
    throw ZipException( OUString( RTL_CONSTASCII_USTRINGPARAM ( "Zip END signature not found!") ), Reference < XInterface> () );
}

sal_Int32 ZipFile::readCEN()
    throw(IOException, ZipException, RuntimeException)
{
    sal_Int32 nEndPos, nLocPos;
    sal_Int16  nCount, nTotal;
    sal_Int32 nCenLen, nCenPos = -1, nCenOff;

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

        if (nTotal<0 || nTotal * CENHDR > nCenLen)
            throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "invalid END header (bad entry count)") ), Reference < XInterface > ());

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

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

        nCenPos = nEndPos - nCenLen;

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

        nLocPos = nCenPos - nCenOff;
        aGrabber.seek(nCenPos);

        ZipEntry *pEntry = new ZipEntry;
        for (nCount = 0 ; nCount < nTotal; nCount++)
        {
            sal_Int32 nTestSig, nCRC, nCompressedSize, nTime, nSize, nExtAttr, nOffset;
            sal_Int16 nVerMade, nVersion, nFlag, nHow, nNameLen, nExtraLen, nCommentLen;
            sal_Int16 nDisk, nIntAttr;

            if (aGrabber.getPosition() - nCenPos + CENHDR > nCenLen)
                throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid CEN header (bad header size check 1)") ), Reference < XInterface > ());

            aGrabber >> nTestSig;
            if (nTestSig != CENSIG)
                throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid CEN header (bad signature)") ), Reference < XInterface > ());

            aGrabber >> nVerMade;
            aGrabber >> nVersion;
            if ((nVersion & 1) == 1)
                throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid CEN header (encrypted entry)") ), Reference < XInterface > ());

            aGrabber >> nFlag;
            aGrabber >> nHow;
            if (nHow != STORED && nHow != DEFLATED)
                throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid CEN header (bad compression method)") ), Reference < XInterface > ());

            aGrabber >> nTime;
            aGrabber >> nCRC;
            aGrabber >> nCompressedSize;
            aGrabber >> nSize;
            aGrabber >> nNameLen;
            aGrabber >> nExtraLen;
            aGrabber >> nCommentLen;
            aGrabber >> nDisk;
            aGrabber >> nIntAttr;
            aGrabber >> nExtAttr;
            aGrabber >> nOffset;

            if (aGrabber.getPosition() - nCenPos + nNameLen + nExtraLen + nCommentLen > nCenLen)
                throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "Invalid CEN header (bad header size check 2)") ), Reference < XInterface > ());

            if (nNameLen > ZIP_MAXNAMELEN)
                throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "name length exceeds 512 bytes" ) ), Reference < XInterface > ());

            if (nExtraLen > ZIP_MAXEXTRA)
                throw ZipException(OUString( RTL_CONSTASCII_USTRINGPARAM ( "extra header info exceeds 256 bytes") ), Reference < XInterface > ());

            pEntry->nTime   = nTime;
            pEntry->nCrc    = nCRC;
            pEntry->nSize   = nSize;
            pEntry->nCompressedSize = nCompressedSize;
            pEntry->nMethod = nHow;
            pEntry->nFlag   = nFlag;
            pEntry->nVersion= nVersion;
            pEntry->nOffset = nOffset + nLocPos;

            pEntry->nOffset *= -1;
            /*
            if (nHow == STORED)
                pEntry->nCompressedSize = 0;
            */
            Sequence < sal_Int8> aSequence (nNameLen);
            aGrabber.readBytes(aSequence, nNameLen);
            pEntry->sName = OUString((sal_Char*)aSequence.getConstArray(), nNameLen, RTL_TEXTENCODING_ASCII_US);

            aGrabber.seek(aGrabber.getPosition() + nExtraLen);
            if (nCommentLen>0)
            {
                Sequence < sal_Int8 > aCommentSeq( nCommentLen );
                aGrabber.readBytes(aCommentSeq, nCommentLen);
                pEntry->sComment = OUString((sal_Char*)aCommentSeq.getConstArray(), nNameLen, RTL_TEXTENCODING_ASCII_US);
            }
            aEntries[pEntry->sName] = *pEntry;
        }
        delete pEntry;

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