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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:06:44 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:06:44 +0000 |
commit | ed5640d8b587fbcfed7dd7967f3de04b37a76f26 (patch) | |
tree | 7a5f7c6c9d02226d7471cb3cc8fbbf631b415303 /oox/source/ole/vbainputstream.cxx | |
parent | Initial commit. (diff) | |
download | libreoffice-ed5640d8b587fbcfed7dd7967f3de04b37a76f26.tar.xz libreoffice-ed5640d8b587fbcfed7dd7967f3de04b37a76f26.zip |
Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | oox/source/ole/vbainputstream.cxx | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/oox/source/ole/vbainputstream.cxx b/oox/source/ole/vbainputstream.cxx new file mode 100644 index 000000000..fc795d30d --- /dev/null +++ b/oox/source/ole/vbainputstream.cxx @@ -0,0 +1,208 @@ +/* -*- 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 <oox/ole/vbainputstream.hxx> +#include <osl/diagnose.h> + +namespace oox::ole { + +namespace { + +const sal_uInt8 VBASTREAM_SIGNATURE = 1; + +const sal_uInt16 VBACHUNK_SIGMASK = 0x7000; +const sal_uInt16 VBACHUNK_SIG = 0x3000; +const sal_uInt16 VBACHUNK_COMPRESSED = 0x8000; +const sal_uInt16 VBACHUNK_LENMASK = 0x0FFF; + +} // namespace + +VbaInputStream::VbaInputStream( BinaryInputStream& rInStrm ) : + BinaryStreamBase( false ), + mpInStrm( &rInStrm ), + mnChunkPos( 0 ) +{ + maChunk.reserve( 4096 ); + + sal_uInt8 nSig = rInStrm.readuInt8(); + OSL_ENSURE( nSig == VBASTREAM_SIGNATURE, "VbaInputStream::VbaInputStream - wrong signature" ); + mbEof = mbEof || rInStrm.isEof() || (nSig != VBASTREAM_SIGNATURE); +} + +sal_Int64 VbaInputStream::size() const +{ + return -1; +} + +sal_Int64 VbaInputStream::tell() const +{ + return -1; +} + +void VbaInputStream::seek( sal_Int64 ) +{ +} + +void VbaInputStream::close() +{ + mpInStrm = nullptr; + mbEof = true; +} + +sal_Int32 VbaInputStream::readData( StreamDataSequence& orData, sal_Int32 nBytes, size_t nAtomSize ) +{ + sal_Int32 nRet = 0; + if( !mbEof ) + { + orData.realloc( ::std::max< sal_Int32 >( nBytes, 0 ) ); + if( nBytes > 0 ) + { + nRet = readMemory( orData.getArray(), nBytes, nAtomSize ); + if( nRet < nBytes ) + orData.realloc( nRet ); + } + } + return nRet; +} + +sal_Int32 VbaInputStream::readMemory( void* opMem, sal_Int32 nBytes, size_t /*nAtomSize*/ ) +{ + sal_Int32 nRet = 0; + sal_uInt8* opnMem = static_cast< sal_uInt8* >( opMem ); + while( (nBytes > 0) && updateChunk() ) + { + sal_Int32 nChunkLeft = static_cast< sal_Int32 >( maChunk.size() - mnChunkPos ); + sal_Int32 nReadBytes = ::std::min( nBytes, nChunkLeft ); + memcpy( opnMem, &*(maChunk.begin() + mnChunkPos), nReadBytes ); + opnMem += nReadBytes; + mnChunkPos += static_cast< size_t >( nReadBytes ); + nBytes -= nReadBytes; + nRet += nReadBytes; + } + return nRet; +} + +void VbaInputStream::skip( sal_Int32 nBytes, size_t /*nAtomSize*/ ) +{ + while( (nBytes > 0) && updateChunk() ) + { + sal_Int32 nChunkLeft = static_cast< sal_Int32 >( maChunk.size() - mnChunkPos ); + sal_Int32 nSkipBytes = ::std::min( nBytes, nChunkLeft ); + mnChunkPos += static_cast< size_t >( nSkipBytes ); + nBytes -= nSkipBytes; + } +} + +// private -------------------------------------------------------------------- + +bool VbaInputStream::updateChunk() +{ + if( mbEof || (mnChunkPos < maChunk.size()) ) return !mbEof; + // try to read next chunk header, this may trigger EOF + sal_uInt16 nHeader = mpInStrm->readuInt16(); + + mbEof = mpInStrm->isEof(); + if( mbEof ) return false; + + // check header signature + bool bIgnoreBrokenSig = ( (nHeader & VBACHUNK_SIGMASK) != VBACHUNK_SIG ); + + // decode length of chunk data and compression flag + bool bCompressed = getFlag( nHeader, VBACHUNK_COMPRESSED ); + sal_uInt16 nChunkLen = (nHeader & VBACHUNK_LENMASK) + 1; + OSL_ENSURE( bCompressed || (nChunkLen == 4096), "VbaInputStream::updateChunk - invalid uncompressed chunk size" ); + + // From the amazing bit detective work of Valek Filippov<frob@gnome.org> + // this tweak and the one at the bottom of the method to seek to the + // start of the next chunk we can read those strange broken + // ( I guess from a MSO bug ) compressed streams > 4k + + if ( bIgnoreBrokenSig ) + { + bCompressed = true; + nChunkLen = 4094; + } + + sal_Int64 target = mpInStrm->tell() + nChunkLen; + if( bCompressed ) + { + maChunk.clear(); + sal_uInt8 nBitCount = 4; + sal_uInt16 nChunkPos = 0; + while( !mbEof && !mpInStrm->isEof() && (nChunkPos < nChunkLen) ) + { + sal_uInt8 nTokenFlags = mpInStrm->readuInt8(); + ++nChunkPos; + for( int nBit = 0; !mbEof && !mpInStrm->isEof() && (nBit < 8) && (nChunkPos < nChunkLen); ++nBit, nTokenFlags >>= 1 ) + { + if( nTokenFlags & 1 ) + { + sal_uInt16 nCopyToken = mpInStrm->readuInt16(); + nChunkPos = nChunkPos + 2; + // update bit count used for offset/length in the token + while( ( static_cast<size_t>(1) << nBitCount ) < maChunk.size() ) ++nBitCount; + // extract length from lower (16-nBitCount) bits, plus 3 + sal_uInt16 nLength = extractValue< sal_uInt16 >( nCopyToken, 0, 16 - nBitCount ) + 3; + // extract offset from high nBitCount bits, plus 1 + sal_uInt16 nOffset = extractValue< sal_uInt16 >( nCopyToken, 16 - nBitCount, nBitCount ) + 1; + mbEof = (nOffset > maChunk.size()) || (maChunk.size() + nLength > 4096); + OSL_ENSURE( !mbEof, "VbaInputStream::updateChunk - invalid offset or size in copy token" ); + if( !mbEof ) + { + // append data to buffer + maChunk.resize( maChunk.size() + nLength ); + sal_uInt8* pnTo = &*(maChunk.end() - nLength); + const sal_uInt8* pnEnd = pnTo + nLength; + const sal_uInt8* pnFrom = pnTo - nOffset; + // offset may be less than length, effectively duplicating source data several times + size_t nRunLen = ::std::min< size_t >( nLength, nOffset ); + while( pnTo < pnEnd ) + { + size_t nStepLen = ::std::min< size_t >( nRunLen, pnEnd - pnTo ); + memcpy( pnTo, pnFrom, nStepLen ); + pnTo += nStepLen; + } + } + } + // we suspect this will never be called + else + { + maChunk.emplace_back(); + maChunk.back() = mpInStrm->readuChar(); + ++nChunkPos; + } + } + } + } + else + { + maChunk.resize( nChunkLen ); + mpInStrm->readMemory(maChunk.data(), nChunkLen); + } + // decompression sometimes leaves the stream pos offset 1 place ( at + // least ) past or before the expected stream pos. + // here we make sure we are on the chunk boundary + mpInStrm->seek( target ); + mnChunkPos = 0; + return !mbEof; +} + +} // namespace oox::ole + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |