ziphandler.cpp

7-Zip 是一款号称有着现今最高压缩比的压缩软件

public:
  CZipDecoder(): _zipCryptoDecoderSpec(0), _aesDecoderSpec(0), filterStreamSpec(0) {}

  HRESULT Decode(
    DECL_EXTERNAL_CODECS_LOC_VARS
    CInArchive &archive, const CItemEx &item,
    ISequentialOutStream *realOutStream,
    IArchiveExtractCallback *extractCallback,
    ICompressProgressInfo *compressProgress,
    UInt32 numThreads, Int32 &res);
};

HRESULT CZipDecoder::Decode(
    DECL_EXTERNAL_CODECS_LOC_VARS
    CInArchive &archive, const CItemEx &item,
    ISequentialOutStream *realOutStream,
    IArchiveExtractCallback *extractCallback,
    ICompressProgressInfo *compressProgress,
    UInt32 numThreads, Int32 &res)
{
  res = NArchive::NExtract::NOperationResult::kDataError;
  CInStreamReleaser inStreamReleaser;

  bool needCRC = true;
  bool aesMode = false;
  #ifdef ZIP_STRONG_SUPORT
  bool pkAesMode = false;
  #endif
  UInt16 methodId = item.CompressionMethod;
  if (item.IsEncrypted())
  {
    if (item.IsStrongEncrypted())
    {
      #ifdef ZIP_STRONG_SUPORT
      CStrongCryptoField f;
      if (item.CentralExtra.GetStrongCryptoField(f))
      {
        pkAesMode = true;
      }
      if (!pkAesMode)
      #endif
      {
        res = NArchive::NExtract::NOperationResult::kUnSupportedMethod;
        return S_OK;
      }
    }
    if (methodId == NFileHeader::NCompressionMethod::kWzAES)
    {
      CWzAesExtraField aesField;
      if (item.CentralExtra.GetWzAesField(aesField))
      {
        aesMode = true;
        needCRC = aesField.NeedCrc();
      }
    }
  }
    
  COutStreamWithCRC *outStreamSpec = new COutStreamWithCRC;
  CMyComPtr<ISequentialOutStream> outStream = outStreamSpec;
  outStreamSpec->SetStream(realOutStream);
  outStreamSpec->Init(needCRC);
  
  UInt64 authenticationPos;
  
  CMyComPtr<ISequentialInStream> inStream;
  {
    UInt64 packSize = item.PackSize;
    if (aesMode)
    {
      if (packSize < NCrypto::NWzAES::kMacSize)
        return S_OK;
      packSize -= NCrypto::NWzAES::kMacSize;
    }
    UInt64 dataPos = item.GetDataPosition();
    inStream.Attach(archive.CreateLimitedStream(dataPos, packSize));
    authenticationPos = dataPos + packSize;
  }
  
  CMyComPtr<ICompressFilter> cryptoFilter;
  if (item.IsEncrypted())
  {
    if (aesMode)
    {
      CWzAesExtraField aesField;
      if (!item.CentralExtra.GetWzAesField(aesField))
        return S_OK;
      methodId = aesField.Method;
      if (!_aesDecoder)
      {
        _aesDecoderSpec = new NCrypto::NWzAES::CDecoder;
        _aesDecoder = _aesDecoderSpec;
      }
      cryptoFilter = _aesDecoder;
      Byte properties = aesField.Strength;
      RINOK(_aesDecoderSpec->SetDecoderProperties2(&properties, 1));
    }
    #ifdef ZIP_STRONG_SUPORT
    else if (pkAesMode)
    {
      if (!_zsDecoder)
      {
        _zsDecoderSpec = new NCrypto::NZipStrong::CDecoder;
        _zsDecoder = _zsDecoderSpec;
      }
      cryptoFilter = _zsDecoder;
    }
    #endif
    else
    {
      if (!_zipCryptoDecoder)
      {
        _zipCryptoDecoderSpec = new NCrypto::NZip::CDecoder;
        _zipCryptoDecoder = _zipCryptoDecoderSpec;
      }
      cryptoFilter = _zipCryptoDecoder;
    }
    CMyComPtr<ICryptoSetPassword> cryptoSetPassword;
    RINOK(cryptoFilter.QueryInterface(IID_ICryptoSetPassword, &cryptoSetPassword));
    
    if (!getTextPassword)
      extractCallback->QueryInterface(IID_ICryptoGetTextPassword, (void **)&getTextPassword);
    
    if (getTextPassword)
    {
      CMyComBSTR password;
      RINOK(getTextPassword->CryptoGetTextPassword(&password));
      AString charPassword;
      if (aesMode
        #ifdef ZIP_STRONG_SUPORT
        || pkAesMode
        #endif
        )
      {
        charPassword = UnicodeStringToMultiByte((const wchar_t *)password, CP_ACP);
        /*
        for (int i = 0;; i++)
        {
          wchar_t c = password[i];
          if (c == 0)
            break;
          if (c >= 0x80)
          {
            res = NArchive::NExtract::NOperationResult::kDataError;
            return S_OK;
          }
          charPassword += (char)c;
        }
        */
      }
      else
      {
        // we use OEM. WinZip/Windows probably use ANSI for some files
        charPassword = UnicodeStringToMultiByte((const wchar_t *)password, CP_OEMCP);
      }
      HRESULT res = cryptoSetPassword->CryptoSetPassword(
        (const Byte *)(const char *)charPassword, charPassword.Length());
      if (res != S_OK)
        return S_OK;
    }
    else
    {
      RINOK(cryptoSetPassword->CryptoSetPassword(0, 0));
    }
  }
  
  int m;
  for (m = 0; m < methodItems.Size(); m++)
    if (methodItems[m].ZipMethod == methodId)
      break;

  if (m == methodItems.Size())
  {
    CMethodItem mi;
    mi.ZipMethod = methodId;
    if (methodId == NFileHeader::NCompressionMethod::kStored)
      mi.Coder = new NCompress::CCopyCoder;
    else if (methodId == NFileHeader::NCompressionMethod::kShrunk)
      mi.Coder = new NCompress::NShrink::CDecoder;
    else if (methodId == NFileHeader::NCompressionMethod::kImploded)
      mi.Coder = new NCompress::NImplode::NDecoder::CCoder;
    else
    {
      CMethodId szMethodID;
      if (methodId == NFileHeader::NCompressionMethod::kBZip2)
        szMethodID = kMethodId_BZip2;
      else
      {
        if (methodId > 0xFF)
        {
          res = NArchive::NExtract::NOperationResult::kUnSupportedMethod;
          return S_OK;
        }
        szMethodID = kMethodId_ZipBase + (Byte)methodId;
      }

      RINOK(CreateCoder(EXTERNAL_CODECS_LOC_VARS szMethodID, mi.Coder, false));

      if (mi.Coder == 0)
      {
        res = NArchive::NExtract::NOperationResult::kUnSupportedMethod;
        return S_OK;
      }
    }
    m = methodItems.Add(mi);
  }
  ICompressCoder *coder = methodItems[m].Coder;
  
  {
    CMyComPtr<ICompressSetDecoderProperties2> setDecoderProperties;
    coder->QueryInterface(IID_ICompressSetDecoderProperties2, (void **)&setDecoderProperties);
    if (setDecoderProperties)
    {
      Byte properties = (Byte)item.Flags;
      RINOK(setDecoderProperties->SetDecoderProperties2(&properties, 1));
    }
  }
  
  #ifdef COMPRESS_MT
  {
    CMyComPtr<ICompressSetCoderMt> setCoderMt;
    coder->QueryInterface(IID_ICompressSetCoderMt, (void **)&setCoderMt);
    if (setCoderMt)
    {
      RINOK(setCoderMt->SetNumberOfThreads(numThreads));
    }
  }
  #endif
  
  {
    HRESULT result;
    CMyComPtr<ISequentialInStream> inStreamNew;
    if (item.IsEncrypted())
    {
      if (!filterStream)
      {
        filterStreamSpec = new CFilterCoder;
        filterStream = filterStreamSpec;
      }
      filterStreamSpec->Filter = cryptoFilter;
      if (aesMode)
      {
        RINOK(_aesDecoderSpec->ReadHeader(inStream));
      }
      #ifdef ZIP_STRONG_SUPORT
      else if (pkAesMode)
      {
        RINOK(_zsDecoderSpec->ReadHeader(inStream));
      }
      #endif
      else
      {
        RINOK(_zipCryptoDecoderSpec->ReadHeader(inStream));
      }
      RINOK(filterStreamSpec->SetInStream(inStream));
      inStreamReleaser.FilterCoder = filterStreamSpec;
      inStreamNew = filterStream;
      
      if (aesMode)
      {
        if (!_aesDecoderSpec->CheckPasswordVerifyCode())
          return S_OK;
      }
    }
    else
      inStreamNew = inStream;
    result = coder->Code(inStreamNew, outStream, NULL, &item.UnPackSize, compressProgress);
    if (result == S_FALSE)
      return S_OK;
    RINOK(result);
  }
  bool crcOK = true;
  bool authOk = true;
  if (needCRC)
    crcOK = (outStreamSpec->GetCRC() == item.FileCRC);
  if (aesMode)
  {
    inStream.Attach(archive.CreateLimitedStream(authenticationPos, NCrypto::NWzAES::kMacSize));
    if (_aesDecoderSpec->CheckMac(inStream, authOk) != S_OK)
      authOk = false;
  }
  
  res = ((crcOK && authOk) ?
    NArchive::NExtract::NOperationResult::kOK :
    NArchive::NExtract::NOperationResult::kCRCError);
  return S_OK;
}


STDMETHODIMP CHandler::Extract(const UInt32* indices, UInt32 numItems,
    Int32 _aTestMode, IArchiveExtractCallback *extractCallback)
{
  COM_TRY_BEGIN
  CZipDecoder myDecoder;
  bool testMode = (_aTestMode != 0);
  UInt64 totalUnPacked = 0, totalPacked = 0;
  bool allFilesMode = (numItems == UInt32(-1));
  if (allFilesMode)
    numItems = m_Items.Size();
  if(numItems == 0)
    return S_OK;
  UInt32 i;
  for(i = 0; i < numItems; i++)
  {
    const CItemEx &item = m_Items[allFilesMode ? i : indices[i]];
    totalUnPacked += item.UnPackSize;
    totalPacked += item.PackSize;
  }
  RINOK(extractCallback->SetTotal(totalUnPacked));

  UInt64 currentTotalUnPacked = 0, currentTotalPacked = 0;
  UInt64 currentItemUnPacked, currentItemPacked;
  
  CLocalProgress *lps = new CLocalProgress;
  CMyComPtr<ICompressProgressInfo> progress = lps;
  lps->Init(extractCallback, false);

  for (i = 0; i < numItems; i++, currentTotalUnPacked += currentItemUnPacked,
      currentTotalPacked += currentItemPacked)
  {
    currentItemUnPacked = 0;
    currentItemPacked = 0;

    lps->InSize = currentTotalPacked;
    lps->OutSize = currentTotalUnPacked;
    RINOK(lps->SetCur());

    CMyComPtr<ISequentialOutStream> realOutStream;
    Int32 askMode = testMode ?
        NArchive::NExtract::NAskMode::kTest :
        NArchive::NExtract::NAskMode::kExtract;
    Int32 index = allFilesMode ? i : indices[i];

    RINOK(extractCallback->GetStream(index, &realOutStream, askMode));

    CItemEx item = m_Items[index];
    if (!item.FromLocal)
    {
      HRESULT res = m_Archive.ReadLocalItemAfterCdItem(item);
      if (res == S_FALSE)
      {
        if (item.IsDir() || realOutStream || testMode)
        {
          RINOK(extractCallback->PrepareOperation(askMode));
          realOutStream.Release();
          RINOK(extractCallback->SetOperationResult(NArchive::NExtract::NOperationResult::kUnSupportedMethod));
        }
        continue;
      }
      RINOK(res);
    }

    if (item.IsDir() || item.IgnoreItem())
    {
      // if (!testMode)
      {
        RINOK(extractCallback->PrepareOperation(askMode));
        realOutStream.Release();
        RINOK(extractCallback->SetOperationResult(NArchive::NExtract::NOperationResult::kOK));
      }
      continue;
    }

    currentItemUnPacked = item.UnPackSize;
    currentItemPacked = item.PackSize;

    if (!testMode && (!realOutStream))
      continue;

    RINOK(extractCallback->PrepareOperation(askMode));

    Int32 res;
    RINOK(myDecoder.Decode(
        EXTERNAL_CODECS_VARS
        m_Archive, item, realOutStream, extractCallback,
        progress, _numThreads, res));
    realOutStream.Release();
    
    RINOK(extractCallback->SetOperationResult(res))
  }
  return S_OK;
  COM_TRY_END
}

IMPL_ISetCompressCodecsInfo

}}