Cppcheck report - LibreOffice 2020-06-13 19:58:00 41c465b5ee443ec04441077b5eb80f263336ea8a, CppCheck 2020-06-13 18:19:47 6d5d12f283cf568d2dfe09aa77cb41f34b322d62: package/source/zipapi/ZipFile.cxx

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   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 .
 */

#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 <com/sun/star/xml/crypto/NSSInitializer.hpp>

#include <comphelper/storagehelper.hxx>
#include <comphelper/processfactory.hxx>
#include <rtl/digest.h>
#include <sal/log.hxx>
#include <osl/diagnose.h>

#include <algorithm>
#include <iterator>
#include <memory>
#include <vector>

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

#include <CRC32.hxx>

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;

using ZipUtils::Inflater;

#if OSL_DEBUG_LEVEL > 0
#define THROW_WHERE SAL_WHERE
#else
#define THROW_WHERE ""
#endif

/** This class is used to read entries from a zip file
 */
ZipFile::ZipFile( const rtl::Reference<comphelper::RefCountedMutex>& aMutexHolder,
                  uno::Reference < XInputStream > const &xInput,
                  const uno::Reference < XComponentContext > & rxContext,
                  bool bInitialise )
: m_aMutexHolder( aMutexHolder )
, aGrabber( xInput )
, aInflater( true )
, xStream(xInput)
, m_xContext ( rxContext )
, bRecoveryMode( false )
{
    if (bInitialise && readCEN() == -1 )
    {
        aEntries.clear();
        throw ZipException( "stream data looks to be broken" );
    }
}

ZipFile::ZipFile( const rtl::Reference< comphelper::RefCountedMutex >& aMutexHolder,
                  uno::Reference < XInputStream > const &xInput,
                  const uno::Reference < XComponentContext > & rxContext,
                  bool bInitialise, bool bForceRecovery)
: m_aMutexHolder( aMutexHolder )
, aGrabber( xInput )
, aInflater( true )
, xStream(xInput)
, m_xContext ( rxContext )
, bRecoveryMode( bForceRecovery )
{
    if (bInitialise)
    {
        if ( bForceRecovery )
        {
            recover();
        }
        else if ( readCEN() == -1 )
        {
            aEntries.clear();
            throw ZipException("stream data looks to be broken" );
        }
    }
}

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

void ZipFile::setInputStream ( const uno::Reference < XInputStream >& xNewStream )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    xStream = xNewStream;
    aGrabber.setInputStream ( xStream );
}

uno::Reference< xml::crypto::XDigestContext > ZipFile::StaticGetDigestContextForChecksum( const uno::Reference< uno::XComponentContext >& xArgContext, const ::rtl::Reference< EncryptionData >& xEncryptionData )
{
    uno::Reference< xml::crypto::XDigestContext > xDigestContext;
    if ( xEncryptionData->m_nCheckAlg == xml::crypto::DigestID::SHA256_1K )
    {
        uno::Reference< uno::XComponentContext > xContext = xArgContext;
        if ( !xContext.is() )
            xContext = comphelper::getProcessComponentContext();

        uno::Reference< xml::crypto::XNSSInitializer > xDigestContextSupplier = xml::crypto::NSSInitializer::create( xContext );

        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 )
    {
        if (xEncryptionData->m_bTryWrongSHA1)
        {
            xDigestContext.set(StarOfficeSHA1DigestContext::Create(), uno::UNO_SET_THROW);
        }
        else
        {
            xDigestContext.set(CorrectSHA1DigestContext::Create(), uno::UNO_SET_THROW);
        }
    }

    return xDigestContext;
}

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

    if (xEncryptionData->m_nDerivedKeySize < 0)
    {
        throw ZipIOException("Invalid derived key length!" );
    }

    uno::Sequence< sal_Int8 > aDerivedKey( xEncryptionData->m_nDerivedKeySize );
    if ( !xEncryptionData->m_nIterationCount &&
         xEncryptionData->m_nDerivedKeySize == xEncryptionData->m_aKey.getLength() )
    {
        // gpg4libre: no need to derive key, m_aKey is already
        // usable as symmetric session key
        aDerivedKey = xEncryptionData->m_aKey;
    }
    else 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("Can not create derived key!" );
    }

    if ( xEncryptionData->m_nEncAlg == xml::crypto::CipherID::AES_CBC_W3C_PADDING )
    {
        uno::Reference< uno::XComponentContext > xContext = xArgContext;
        if ( !xContext.is() )
            xContext = comphelper::getProcessComponentContext();

        uno::Reference< xml::crypto::XNSSInitializer > xCipherContextSupplier = xml::crypto::NSSInitializer::create( xContext );

        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("Unknown cipher algorithm is requested!" );
    }

    return xResult;
}

void ZipFile::StaticFillHeader( const ::rtl::Reference< EncryptionData >& rData,
                                sal_Int64 nSize,
                                const 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);

    // FIXME64: need to handle larger sizes
    // 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
    memcpy ( pHeader, rData->m_aSalt.getConstArray(), nSaltLength );
    pHeader += nSaltLength;

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

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

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

bool ZipFile::StaticFillData (  ::rtl::Reference< BaseEncryptionData > const & rData,
                                    sal_Int32 &rEncAlg,
                                    sal_Int32 &rChecksumAlg,
                                    sal_Int32 &rDerivedKeySize,
                                    sal_Int32 &rStartKeyGenID,
                                    sal_Int32 &rSize,
                                    OUString& aMediaType,
                                    const uno::Reference< XInputStream >& rStream )
{
    bool bOk = 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 );
                memcpy ( rData->m_aSalt.getArray(), aBuffer.getConstArray(), nSaltLength );
                if ( nIVLength == rStream->readBytes ( aBuffer, nIVLength ) )
                {
                    rData->m_aInitVector.realloc ( nIVLength );
                    memcpy ( rData->m_aInitVector.getArray(), aBuffer.getConstArray(), nIVLength );
                    if ( nDigestLength == rStream->readBytes ( aBuffer, nDigestLength ) )
                    {
                        rData->m_aDigest.realloc ( nDigestLength );
                        memcpy ( rData->m_aDigest.getArray(), aBuffer.getConstArray(), nDigestLength );

                        if ( nMediaTypeLength == rStream->readBytes ( aBuffer, nMediaTypeLength ) )
                        {
                            aMediaType = OUString( reinterpret_cast<sal_Unicode const *>(aBuffer.getConstArray()),
                                                            nMediaTypeLength / sizeof( sal_Unicode ) );
                            bOk = true;
                        }
                    }
                }
            }
        }
    }
    return bOk;
}

uno::Reference< XInputStream > ZipFile::StaticGetDataFromRawStream( const rtl::Reference< comphelper::RefCountedMutex >& aMutexHolder,
                                                                const uno::Reference< uno::XComponentContext >& rxContext,
                                                                const uno::Reference< XInputStream >& xStream,
                                                                const ::rtl::Reference< EncryptionData > &rData )
{
    if ( !rData.is() )
        throw ZipIOException("Encrypted stream without encryption data!" );

    if ( !rData->m_aKey.hasElements() )
        throw packages::WrongPasswordException(THROW_WHERE );

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

    // 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.hasElements(), "Can't detect password correctness without digest!" );
    if ( rData->m_aDigest.hasElements() )
    {
        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( rxContext, aReadBuffer, rData ) )
            throw packages::WrongPasswordException(THROW_WHERE );
    }

    return new XUnbufferedStream( aMutexHolder, 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

bool ZipFile::StaticHasValidPassword( const uno::Reference< uno::XComponentContext >& rxContext, const Sequence< sal_Int8 > &aReadBuffer, const ::rtl::Reference< EncryptionData > &rData )
{
    if ( !rData.is() || !rData->m_aKey.hasElements() )
        return false;

    bool bRet = false;

    uno::Reference< xml::crypto::XCipherContext > xCipher( StaticGetCipher( rxContext, 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.hasElements() )
    {
        sal_Int32 nOldLen = aDecryptBuffer.getLength();
        aDecryptBuffer.realloc( nOldLen + aDecryptBuffer2.getLength() );
        memcpy( 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( rxContext, 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.hasElements() &&
          ( aDigestSeq.getLength() != rData->m_aDigest.getLength() ||
            0 != memcmp ( aDigestSeq.getConstArray(),
                                     rData->m_aDigest.getConstArray(),
                                    aDigestSeq.getLength() ) ) )
    {
        // We should probably tell the user that the password they entered was wrong
    }
    else
        bRet = true;

    return bRet;
}

bool ZipFile::hasValidPassword ( ZipEntry const & rEntry, const ::rtl::Reference< EncryptionData >& rData )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    bool bRet = false;
    if ( rData.is() && rData->m_aKey.hasElements() )
    {
        css::uno::Reference < css::io::XSeekable > xSeek(xStream, UNO_QUERY_THROW);
        xSeek->seek( rEntry.nOffset );
        sal_Int64 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_xContext, aReadBuffer, rData );
    }

    return bRet;
}

namespace {

class XBufferedStream : public cppu::WeakImplHelper<css::io::XInputStream, css::io::XSeekable>
{
    std::vector<sal_Int8> maBytes;
    size_t mnPos;

    size_t remainingSize() const
    {
        return maBytes.size() - mnPos;
    }

    bool hasBytes() const
    {
        return mnPos < maBytes.size();
    }

public:
    XBufferedStream( const uno::Reference<XInputStream>& xSrcStream ) : mnPos(0)
<--- Class 'XBufferedStream' has a constructor with 1 argument that is not explicit. [+]
Class 'XBufferedStream' has a constructor with 1 argument that is not explicit. Such constructors should in general be explicit for type safety reasons. Using the explicit keyword in the constructor means some mistakes when using the class can be avoided.
    {
        const sal_Int32 nBufSize = 8192;

        sal_Int32 nRemaining = xSrcStream->available();
        sal_Int32 nRead = 0;
        maBytes.reserve(nRemaining);
        uno::Sequence<sal_Int8> aBuf(nBufSize);

        auto readAndCopy = [&]( sal_Int32 nReadSize ) -> sal_Int32
        {
            sal_Int32 nBytes = xSrcStream->readBytes(aBuf, nReadSize);
            const sal_Int8* p = aBuf.getArray();
            const sal_Int8* pEnd = p + nBytes;
            std::copy(p, pEnd, std::back_inserter(maBytes));
            return nBytes;
        };

        while (nRemaining > nBufSize)
        {
            const auto nBytes = readAndCopy(nBufSize);
            if (!nBytes)
                break;
            nRead += nBytes;
            nRemaining -= nBytes;
        }

        if (nRemaining)
            nRead += readAndCopy(nRemaining);
        maBytes.resize(nRead);
    }

    virtual sal_Int32 SAL_CALL readBytes( uno::Sequence<sal_Int8>& rData, sal_Int32 nBytesToRead ) override
    {
        if (!hasBytes())
            return 0;

        sal_Int32 nReadSize = std::min<sal_Int32>(nBytesToRead, remainingSize());
        rData.realloc(nReadSize);
        std::vector<sal_Int8>::const_iterator it = maBytes.cbegin();
        std::advance(it, mnPos);
        for (sal_Int32 i = 0; i < nReadSize; ++i, ++it)
            rData[i] = *it;

        mnPos += nReadSize;

        return nReadSize;
    }

    virtual sal_Int32 SAL_CALL readSomeBytes( ::css::uno::Sequence<sal_Int8>& rData, sal_Int32 nMaxBytesToRead ) override
    {
        return readBytes(rData, nMaxBytesToRead);
    }

    virtual void SAL_CALL skipBytes( sal_Int32 nBytesToSkip ) override
    {
        if (!hasBytes())
            return;

        mnPos += nBytesToSkip;
    }

    virtual sal_Int32 SAL_CALL available() override
    {
        if (!hasBytes())
            return 0;

        return remainingSize();
    }

    virtual void SAL_CALL closeInput() override
    {
    }
    // XSeekable
    virtual void SAL_CALL seek( sal_Int64 location ) override
    {
        if ( location > sal_Int64(maBytes.size()) || location < 0 )
            throw IllegalArgumentException(THROW_WHERE, uno::Reference< uno::XInterface >(), 1 );
        mnPos = location;
    }
    virtual sal_Int64 SAL_CALL getPosition() override
    {
        return mnPos;
    }
    virtual sal_Int64 SAL_CALL getLength() override
    {
        return maBytes.size();
    }
};

}

uno::Reference< XInputStream > ZipFile::createStreamForZipEntry(
            const rtl::Reference< comphelper::RefCountedMutex >& aMutexHolder,
            ZipEntry const & rEntry,
            const ::rtl::Reference< EncryptionData > &rData,
            sal_Int8 nStreamMode,
            bool bIsEncrypted,
            const bool bUseBufferedStream,
            const OUString& aMediaType )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    rtl::Reference< XUnbufferedStream > xSrcStream = new XUnbufferedStream(
        m_xContext, aMutexHolder, rEntry, xStream, rData, nStreamMode, bIsEncrypted, aMediaType, bRecoveryMode);

    if (!bUseBufferedStream)
        return xSrcStream.get();

    uno::Reference<io::XInputStream> xBufStream;
    static const sal_Int32 nThreadingThreshold = 10000;

    if( xSrcStream->available() > nThreadingThreshold )
        xBufStream = new XBufferedThreadedStream(xSrcStream.get(), xSrcStream->getSize());
    else
        xBufStream = new XBufferedStream(xSrcStream.get());

    return xBufStream;
}

std::unique_ptr<ZipEnumeration> ZipFile::entries()
{
    return std::make_unique<ZipEnumeration>(aEntries);
}

uno::Reference< XInputStream > ZipFile::getInputStream( ZipEntry& rEntry,
        const ::rtl::Reference< EncryptionData > &rData,
        bool bIsEncrypted,
        const rtl::Reference<comphelper::RefCountedMutex>& aMutexHolder )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    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

    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.hasElements() )
        bNeedRawStream = !hasValidPassword ( rEntry, rData );

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

uno::Reference< XInputStream > ZipFile::getDataStream( ZipEntry& rEntry,
        const ::rtl::Reference< EncryptionData > &rData,
        bool bIsEncrypted,
        const rtl::Reference<comphelper::RefCountedMutex>& aMutexHolder )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    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
    bool bNeedRawStream = false;
    if ( bIsEncrypted )
    {
        // in case no digest is provided there is no way
        // to detect password correctness
        if ( !rData.is() )
            throw ZipException("Encrypted stream without encryption data!" );

        // 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.hasElements(), "Can't detect password correctness without digest!" );
        if ( rData->m_aDigest.hasElements() && !hasValidPassword ( rEntry, rData ) )
                throw packages::WrongPasswordException(THROW_WHERE );
    }
    else
        bNeedRawStream = ( rEntry.nMethod == STORED );

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

uno::Reference< XInputStream > ZipFile::getRawData( ZipEntry& rEntry,
        const ::rtl::Reference< EncryptionData >& rData,
        bool bIsEncrypted,
        const rtl::Reference<comphelper::RefCountedMutex>& aMutexHolder,
        const bool bUseBufferedStream )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

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

    return createStreamForZipEntry ( aMutexHolder, rEntry, rData, UNBUFF_STREAM_RAW, bIsEncrypted, bUseBufferedStream );
}

uno::Reference< XInputStream > ZipFile::getWrappedRawStream(
        ZipEntry& rEntry,
        const ::rtl::Reference< EncryptionData >& rData,
        const OUString& aMediaType,
        const rtl::Reference<comphelper::RefCountedMutex>& aMutexHolder )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    if ( !rData.is() )
        throw packages::NoEncryptionException(THROW_WHERE );

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

    return createStreamForZipEntry ( aMutexHolder, rEntry, rData, UNBUFF_STREAM_WRAPPEDRAW, true, true, aMediaType );
}

void ZipFile::readLOC( ZipEntry &rEntry )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    sal_Int64 nPos = -rEntry.nOffset;

    aGrabber.seek(nPos);
    sal_Int32 nTestSig = aGrabber.ReadInt32();
    if (nTestSig != LOCSIG)
        throw ZipIOException("Invalid LOC header (bad signature)" );

    // Ignore all (duplicated) information from the local file header.
    // various programs produced "broken" zip files; even LO at some point.
    // Just verify the path and calculate the data offset and otherwise
    // rely on the central directory info.

    aGrabber.ReadInt16(); //version
    aGrabber.ReadInt16(); //flag
    aGrabber.ReadInt16(); //how
    aGrabber.ReadInt32(); //time
    aGrabber.ReadInt32(); //crc
    aGrabber.ReadInt32(); //compressed size
    aGrabber.ReadInt32(); //size
    sal_Int16 nPathLen = aGrabber.ReadInt16();
    sal_Int16 nExtraLen = aGrabber.ReadInt16();
    rEntry.nOffset = aGrabber.getPosition() + nPathLen + nExtraLen;

    // FIXME64: need to read 64bit LOC

    bool bBroken = false;

    try
    {
        sal_Int16 nPathLenToRead = nPathLen;
        const sal_Int64 nBytesAvailable = aGrabber.getLength() - aGrabber.getPosition();
        if (nPathLenToRead > nBytesAvailable)
            nPathLenToRead = nBytesAvailable;
        else if (nPathLenToRead < 0)
            nPathLenToRead = 0;

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

        OUString sLOCPath = OUString::intern( reinterpret_cast<char *>(aNameBuffer.getArray()),
                                                          aNameBuffer.getLength(),
                                                          RTL_TEXTENCODING_UTF8 );

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

        bBroken = rEntry.nPathLen != nPathLen
                        || rEntry.sPath != sLOCPath;
    }
    catch(...)
    {
        bBroken = true;
    }

    if ( bBroken && !bRecoveryMode )
        throw ZipIOException("The stream seems to be broken!" );
}

sal_Int32 ZipFile::findEND()
{
    // 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 < ENDHDR)
            return -1;
        nPos = nLength - ENDHDR - ZIP_MAXNAMELEN;
        nEnd = nPos >= 0 ? nPos : 0 ;

        aGrabber.seek( nEnd );

        auto nSize = nLength - nEnd;
        if (nSize != aGrabber.readBytes(aBuffer, nSize))
            throw ZipException("Zip END signature not found!" );

        const sal_Int8 *pBuffer = aBuffer.getConstArray();

        nPos = nSize - 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("Zip END signature not found!" );
    }
    catch ( NotConnectedException& )
    {
        throw ZipException("Zip END signature not found!" );
    }
    catch ( BufferSizeExceededException& )
    {
        throw ZipException("Zip END signature not found!" );
    }
    throw ZipException("Zip END signature not found!" );
}

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

    try
    {
        nEndPos = findEND();
        if (nEndPos == -1)
            return -1;
        aGrabber.seek(nEndPos + ENDTOT);
        sal_uInt16 nTotal = aGrabber.ReadUInt16();
        sal_Int32 nCenLen = aGrabber.ReadInt32();
        sal_Int32 nCenOff = aGrabber.ReadInt32();

        if ( nTotal * CENHDR > nCenLen )
            throw ZipException("invalid END header (bad entry count)" );

        if ( nTotal > ZIP_MAXENTRIES )
            throw ZipException("too many entries in ZIP File" );

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

        nCenPos = nEndPos - nCenLen;

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

        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 ("Error reading CEN into memory buffer!" );

        MemoryByteGrabber aMemGrabber(aCENBuffer);

        ZipEntry aEntry;
        sal_Int16 nCommentLen;

        for (nCount = 0 ; nCount < nTotal; nCount++)
        {
            sal_Int32 nTestSig = aMemGrabber.ReadInt32();
            if ( nTestSig != CENSIG )
                throw ZipException("Invalid CEN header (bad signature)" );

            aMemGrabber.skipBytes ( 2 );
            aEntry.nVersion = aMemGrabber.ReadInt16();

            if ( ( aEntry.nVersion & 1 ) == 1 )
                throw ZipException("Invalid CEN header (encrypted entry)" );

            aEntry.nFlag = aMemGrabber.ReadInt16();
            aEntry.nMethod = aMemGrabber.ReadInt16();

            if ( aEntry.nMethod != STORED && aEntry.nMethod != DEFLATED)
                throw ZipException("Invalid CEN header (bad compression method)" );

            aEntry.nTime = aMemGrabber.ReadInt32();
            aEntry.nCrc = aMemGrabber.ReadInt32();

            sal_uInt32 nCompressedSize = aMemGrabber.ReadUInt32();
            sal_uInt32 nSize = aMemGrabber.ReadUInt32();
            aEntry.nPathLen = aMemGrabber.ReadInt16();
            aEntry.nExtraLen = aMemGrabber.ReadInt16();
            nCommentLen = aMemGrabber.ReadInt16();
            aMemGrabber.skipBytes ( 8 );
            sal_uInt32 nOffset = aMemGrabber.ReadUInt32();

            // FIXME64: need to read the 64bit header instead
            if ( nSize == 0xffffffff ||
                 nOffset == 0xffffffff ||
                 nCompressedSize == 0xffffffff ) {
                throw ZipException("PK64 zip file entry" );
            }
            aEntry.nCompressedSize = nCompressedSize;
            aEntry.nSize = nSize;
            aEntry.nOffset = nOffset;

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

            if ( aEntry.nPathLen < 0 )
                throw ZipException("unexpected name length" );

            if ( nCommentLen < 0 )
                throw ZipException("unexpected comment length" );

            if ( aEntry.nExtraLen < 0 )
                throw ZipException("unexpected extra header info length" );

            if (aEntry.nPathLen > aMemGrabber.remainingSize())
                throw ZipException("name too long");

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

            if ( !::comphelper::OStorageHelper::IsValidZipEntryFileName( aEntry.sPath, true ) )
                throw ZipException("Zip entry has an invalid name." );

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

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

void ZipFile::recover()
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    sal_Int64 nLength;
    Sequence < sal_Int8 > aBuffer;

    try
    {
        nLength = aGrabber.getLength();
        if (nLength < ENDHDR)
            return;

        aGrabber.seek( 0 );

        const sal_Int64 nToRead = 32000;
        for( sal_Int64 nGenPos = 0; aGrabber.readBytes( aBuffer, nToRead ) && aBuffer.getLength() > 16; )
        {
            const sal_Int8 *pBuffer = aBuffer.getConstArray();
            sal_Int32 nBufSize = aBuffer.getLength();

            sal_Int64 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
                || ( nBufSize < 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;
                    Sequence<sal_Int8> aTmpBuffer(&(pBuffer[nPos+4]), 26);
                    MemoryByteGrabber aMemGrabber(aTmpBuffer);

                    aEntry.nVersion = aMemGrabber.ReadInt16();
                    if ( ( aEntry.nVersion & 1 ) != 1 )
                    {
                        aEntry.nFlag = aMemGrabber.ReadInt16();
                        aEntry.nMethod = aMemGrabber.ReadInt16();

                        if ( aEntry.nMethod == STORED || aEntry.nMethod == DEFLATED )
                        {
                            aEntry.nTime = aMemGrabber.ReadInt32();
                            aEntry.nCrc = aMemGrabber.ReadInt32();
                            sal_uInt32 nCompressedSize = aMemGrabber.ReadUInt32();
                            sal_uInt32 nSize = aMemGrabber.ReadUInt32();
                            aEntry.nPathLen = aMemGrabber.ReadInt16();
                            aEntry.nExtraLen = aMemGrabber.ReadInt16();

                            // FIXME64: need to read the 64bit header instead
                            if ( nSize == 0xffffffff ||
                                 nCompressedSize == 0xffffffff ) {
                                throw ZipException("PK64 zip file entry" );
                            }
                            aEntry.nCompressedSize = nCompressedSize;
                            aEntry.nSize = nSize;

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

                            sal_Int64 nDataSize = ( aEntry.nMethod == DEFLATED ) ? aEntry.nCompressedSize : aEntry.nSize;
                            sal_Int64 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 ( reinterpret_cast<char const *>(&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 ( reinterpret_cast<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;
                                }

                                aEntries.emplace( aEntry.sPath, aEntry );
                            }
                        }
                    }

                    nPos += 4;
                }
                else if (pBuffer[nPos] == 'P' && pBuffer[nPos+1] == 'K' && pBuffer[nPos+2] == 7 && pBuffer[nPos+3] == 8 )
                {
                    sal_Int64 nCompressedSize, nSize;
                    Sequence<sal_Int8> aTmpBuffer(&(pBuffer[nPos+4]), 12);
                    MemoryByteGrabber aMemGrabber(aTmpBuffer);
                    sal_Int32 nCRC32 = aMemGrabber.ReadInt32();
                    sal_uInt32 nCompressedSize32 = aMemGrabber.ReadUInt32();
                    sal_uInt32 nSize32 = aMemGrabber.ReadUInt32();

                    // FIXME64: work to be done here ...
                    nCompressedSize = nCompressedSize32;
                    nSize = nSize32;

                    for( auto& rEntry : aEntries )
                    {
                        // this is a broken package, accept this block not only for DEFLATED streams
                        if( rEntry.second.nFlag & 8 )
                        {
                            sal_Int64 nStreamOffset = nGenPos + nPos - nCompressedSize;
                            if ( nStreamOffset == rEntry.second.nOffset && nCompressedSize > rEntry.second.nCompressedSize )
                            {
                                // only DEFLATED blocks need to be checked
                                bool bAcceptBlock = ( rEntry.second.nMethod == STORED && nCompressedSize == nSize );

                                if ( !bAcceptBlock )
                                {
                                    sal_Int64 nRealSize = 0;
                                    sal_Int32 nRealCRC = 0;
                                    getSizeAndCRC( nStreamOffset, nCompressedSize, &nRealSize, &nRealCRC );
                                    bAcceptBlock = ( nRealSize == nSize && nRealCRC == nCRC32 );
                                }

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

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

            nGenPos += nPos;
            aGrabber.seek( nGenPos );
        }
    }
    catch ( IllegalArgumentException& )
    {
        throw ZipException("Zip END signature not found!" );
    }
    catch ( NotConnectedException& )
    {
        throw ZipException("Zip END signature not found!" );
    }
    catch ( BufferSizeExceededException& )
    {
        throw ZipException("Zip END signature not found!" );
    }
}

bool ZipFile::checkSizeAndCRC( const ZipEntry& aEntry )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    sal_Int32 nCRC = 0;
    sal_Int64 nSize = 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_Int64 nOffset, sal_Int64 nSize )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    Sequence < sal_Int8 > aBuffer;
    CRC32 aCRC;
    sal_Int64 nBlockSize = ::std::min(nSize, static_cast< sal_Int64 >(32000));

    aGrabber.seek( nOffset );
    for (sal_Int64 ind = 0;
         aGrabber.readBytes( aBuffer, nBlockSize ) && ind * nBlockSize < nSize;
         ++ind)
    {
        sal_Int64 nLen = ::std::min(nBlockSize, nSize - ind * nBlockSize);
        aCRC.updateSegment(aBuffer, static_cast<sal_Int32>(nLen));
    }

    return aCRC.getValue();
}

void ZipFile::getSizeAndCRC( sal_Int64 nOffset, sal_Int64 nCompressedSize, sal_Int64 *nSize, sal_Int32 *nCRC )
{
    ::osl::MutexGuard aGuard( m_aMutexHolder->GetMutex() );

    Sequence < sal_Int8 > aBuffer;
    CRC32 aCRC;
    sal_Int64 nRealSize = 0;
    Inflater aInflaterLocal( true );
    sal_Int32 nBlockSize = static_cast< sal_Int32 > (::std::min( nCompressedSize, static_cast< sal_Int64 >( 32000 ) ) );

    aGrabber.seek( nOffset );
    for ( sal_Int64 ind = 0;
          !aInflaterLocal.finished() && aGrabber.readBytes( aBuffer, nBlockSize ) && ind * nBlockSize < nCompressedSize;
          ind++ )
    {
        Sequence < sal_Int8 > aData( nBlockSize );
        sal_Int32 nLastInflated = 0;
        sal_Int64 nInBlock = 0;

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

        nRealSize += nInBlock;
    }

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

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */