コード例 #1
0
 // For AES the method in the entry is 99, and the real compression method is in the extradata
 //
 private void ProcessAESExtraData(ZipExtraData extraData)
 {
     #if !NET_1_1 && !NETCF_2_0
     if (extraData.Find(0x9901))
     {
         // Set version and flag for Zipfile.CreateAndInitDecryptionStream
         versionToExtract = ZipConstants.VERSION_AES;			// Ver 5.1 = AES see "Version" getter
         // Set StrongEncryption flag for ZipFile.CreateAndInitDecryptionStream
         Flags = Flags | (int)GeneralBitFlags.StrongEncryption;
         //
         // Unpack AES extra data field see http://www.winzip.com/aes_info.htm
         int length = extraData.ValueLength;			// Data size currently 7
         if (length < 7)
             throw new ZipException("AES Extra Data Length " + length + " invalid.");
         int ver = extraData.ReadShort();			// Version number (1=AE-1 2=AE-2)
         int vendorId = extraData.ReadShort();		// 2-character vendor ID 0x4541 = "AE"
         int encrStrength = extraData.ReadByte();	// encryption strength 1 = 128 2 = 192 3 = 256
         int actualCompress = extraData.ReadShort(); // The actual compression method used to compress the file
         _aesVer = ver;
         _aesEncryptionStrength = encrStrength;
         method = (CompressionMethod)actualCompress;
     }
     else
         throw new ZipException("AES Extra Data missing");
     #else
         throw new ZipException("AES unsupported");
     #endif
 }
コード例 #2
0
        // Write the local file header
        // TODO: ZipHelperStream.WriteLocalHeader is not yet used and needs checking for ZipFile and ZipOuptutStream usage
        void WriteLocalHeader(ZipEntry entry, EntryPatchData patchData)
        {
            CompressionMethod method = entry.CompressionMethod;
            bool headerInfoAvailable = true; // How to get this?
            bool patchEntryHeader    = false;

            WriteLEInt(ZipConstants.LocalHeaderSignature);

            WriteLEShort(entry.Version);
            WriteLEShort(entry.Flags);
            WriteLEShort((byte)method);
            WriteLEInt((int)entry.DosTime);

            if (headerInfoAvailable == true)
            {
                WriteLEInt((int)entry.Crc);
                if (entry.LocalHeaderRequiresZip64)
                {
                    WriteLEInt(-1);
                    WriteLEInt(-1);
                }
                else
                {
                    WriteLEInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
                    WriteLEInt((int)entry.Size);
                }
            }
            else
            {
                if (patchData != null)
                {
                    patchData.CrcPatchOffset = stream_.Position;
                }
                WriteLEInt(0);  // Crc

                if (patchData != null)
                {
                    patchData.SizePatchOffset = stream_.Position;
                }

                // For local header both sizes appear in Zip64 Extended Information
                if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
                {
                    WriteLEInt(-1);
                    WriteLEInt(-1);
                }
                else
                {
                    WriteLEInt(0);      // Compressed size
                    WriteLEInt(0);      // Uncompressed size
                }
            }

            byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);

            if (name.Length > 0xFFFF)
            {
                throw new ZipException("Entry name too long.");
            }

            ZipExtraData ed = new ZipExtraData(entry.ExtraData);

            if (entry.LocalHeaderRequiresZip64 && (headerInfoAvailable || patchEntryHeader))
            {
                ed.StartNewEntry();
                if (headerInfoAvailable)
                {
                    ed.AddLeLong(entry.Size);
                    ed.AddLeLong(entry.CompressedSize);
                }
                else
                {
                    ed.AddLeLong(-1);
                    ed.AddLeLong(-1);
                }
                ed.AddNewEntry(1);

                if (!ed.Find(1))
                {
                    throw new ZipException("Internal error cant find extra data");
                }

                if (patchData != null)
                {
                    patchData.SizePatchOffset = ed.CurrentReadIndex;
                }
            }
            else
            {
                ed.Delete(1);
            }

            byte[] extra = ed.GetEntryData();

            WriteLEShort(name.Length);
            WriteLEShort(extra.Length);

            if (name.Length > 0)
            {
                stream_.Write(name, 0, name.Length);
            }

            if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
            {
                patchData.SizePatchOffset += stream_.Position;
            }

            if (extra.Length > 0)
            {
                stream_.Write(extra, 0, extra.Length);
            }
        }
コード例 #3
0
        /// <summary>
        /// Process extra data fields updating the entry based on the contents.
        /// </summary>
        /// <param name="localHeader">True if the extra data fields should be handled
        /// for a local header, rather than for a central header.
        /// </param>
        internal void ProcessExtraData(bool localHeader)
        {
            ZipExtraData extraData = new ZipExtraData(this.extra);

            if (extraData.Find(0x0001))
            {
                // Version required to extract is ignored here as some archivers dont set it correctly
                // in theory it should be version 45 or higher

                // The recorded size will change but remember that this is zip64.
                forceZip64_ = true;

                if (extraData.ValueLength < 4)
                {
                    throw new ZipException("Extra data extended Zip64 information length is invalid");
                }

                if (localHeader || (size == uint.MaxValue))
                {
                    size = (ulong)extraData.ReadLong();
                }

                if (localHeader || (compressedSize == uint.MaxValue))
                {
                    compressedSize = (ulong)extraData.ReadLong();
                }

                if (!localHeader && (offset == uint.MaxValue))
                {
                    offset = extraData.ReadLong();
                }

                // Disk number on which file starts is ignored
            }
            else
            {
                if (
                    ((versionToExtract & 0xff) >= ZipConstants.VersionZip64) &&
                    ((size == uint.MaxValue) || (compressedSize == uint.MaxValue))
                )
                {
                    throw new ZipException("Zip64 Extended information required but is missing.");
                }
            }

            if (extraData.Find(10))
            {
                // No room for any tags.
                if (extraData.ValueLength < 4)
                {
                    throw new ZipException("NTFS Extra data invalid");
                }

                extraData.ReadInt(); // Reserved

                while (extraData.UnreadCount >= 4)
                {
                    int ntfsTag = extraData.ReadShort();
                    int ntfsLength = extraData.ReadShort();
                    if (ntfsTag == 1)
                    {
                        if (ntfsLength >= 24)
                        {
                            long lastModification = extraData.ReadLong();
                            long lastAccess = extraData.ReadLong();
                            long createTime = extraData.ReadLong();

                            DateTime = System.DateTime.FromFileTime(lastModification);
                        }
                        break;
                    }
                    else
                    {
                        // An unknown NTFS tag so simply skip it.
                        extraData.Skip(ntfsLength);
                    }
                }
            }
            else if (extraData.Find(0x5455))
            {
                int length = extraData.ValueLength;
                int flags = extraData.ReadByte();

                // Can include other times but these are ignored.  Length of data should
                // actually be 1 + 4 * no of bits in flags.
                if (((flags & 1) != 0) && (length >= 5))
                {
                    int iTime = extraData.ReadInt();

                    DateTime = (new System.DateTime(1970, 1, 1, 0, 0, 0).ToUniversalTime() +
                        new TimeSpan(0, 0, 0, iTime, 0)).ToLocalTime();
                }
            }
            if (method == CompressionMethod.WinZipAES)
            {
                ProcessAESExtraData(extraData);
            }
        }
コード例 #4
0
        // Write the local file header
        // TODO: ZipHelperStream.WriteLocalHeader is not yet used and needs checking for ZipFile and ZipOuptutStream usage
        void WriteLocalHeader(ZipEntry entry, EntryPatchData patchData)
        {
            CompressionMethod method = entry.CompressionMethod;
            bool headerInfoAvailable = true; // How to get this?
            bool patchEntryHeader = false;

            WriteLEInt(ZipConstants.LocalHeaderSignature);

            WriteLEShort(entry.Version);
            WriteLEShort(entry.Flags);
            WriteLEShort((byte)method);
            WriteLEInt((int)entry.DosTime);

            if (headerInfoAvailable == true)
            {
                WriteLEInt((int)entry.Crc);
                if (entry.LocalHeaderRequiresZip64)
                {
                    WriteLEInt(-1);
                    WriteLEInt(-1);
                }
                else
                {
                    WriteLEInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
                    WriteLEInt((int)entry.Size);
                }
            }
            else
            {
                if (patchData != null)
                {
                    patchData.CrcPatchOffset = stream_.Position;
                }
                WriteLEInt(0);	// Crc

                if (patchData != null)
                {
                    patchData.SizePatchOffset = stream_.Position;
                }

                // For local header both sizes appear in Zip64 Extended Information
                if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
                {
                    WriteLEInt(-1);
                    WriteLEInt(-1);
                }
                else
                {
                    WriteLEInt(0);	// Compressed size
                    WriteLEInt(0);	// Uncompressed size
                }
            }

            byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);

            if (name.Length > 0xFFFF)
            {
                throw new ZipException("Entry name too long.");
            }

            ZipExtraData ed = new ZipExtraData(entry.ExtraData);

            if (entry.LocalHeaderRequiresZip64 && (headerInfoAvailable || patchEntryHeader))
            {
                ed.StartNewEntry();
                if (headerInfoAvailable)
                {
                    ed.AddLeLong(entry.Size);
                    ed.AddLeLong(entry.CompressedSize);
                }
                else
                {
                    ed.AddLeLong(-1);
                    ed.AddLeLong(-1);
                }
                ed.AddNewEntry(1);

                if (!ed.Find(1))
                {
                    throw new ZipException("Internal error cant find extra data");
                }

                if (patchData != null)
                {
                    patchData.SizePatchOffset = ed.CurrentReadIndex;
                }
            }
            else
            {
                ed.Delete(1);
            }

            byte[] extra = ed.GetEntryData();

            WriteLEShort(name.Length);
            WriteLEShort(extra.Length);

            if (name.Length > 0)
            {
                stream_.Write(name, 0, name.Length);
            }

            if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
            {
                patchData.SizePatchOffset += stream_.Position;
            }

            if (extra.Length > 0)
            {
                stream_.Write(extra, 0, extra.Length);
            }
        }
コード例 #5
0
        /// <summary>
        /// Process extra data fields updating the entry based on the contents.
        /// </summary>
        /// <param name="localHeader">True if the extra data fields should be handled
        /// for a local header, rather than for a central header.
        /// </param>
        internal void ProcessExtraData(bool localHeader)
        {
            ZipExtraData extraData = new ZipExtraData(this.extra);

            if (extraData.Find(0x0001))
            {
                // Version required to extract is ignored here as some archivers dont set it correctly
                // in theory it should be version 45 or higher

                // The recorded size will change but remember that this is zip64.
                forceZip64_ = true;

                if (extraData.ValueLength < 4)
                {
                    throw new ZipException("Extra data extended Zip64 information length is invalid");
                }

                if (localHeader || (size == uint.MaxValue))
                {
                    size = (ulong)extraData.ReadLong();
                }

                if (localHeader || (compressedSize == uint.MaxValue))
                {
                    compressedSize = (ulong)extraData.ReadLong();
                }

                if (!localHeader && (offset == uint.MaxValue))
                {
                    offset = extraData.ReadLong();
                }

                // Disk number on which file starts is ignored
            }
            else
            {
                if (
                    ((versionToExtract & 0xff) >= ZipConstants.VersionZip64) &&
                    ((size == uint.MaxValue) || (compressedSize == uint.MaxValue))
                    )
                {
                    throw new ZipException("Zip64 Extended information required but is missing.");
                }
            }

            if (extraData.Find(10))
            {
                // No room for any tags.
                if (extraData.ValueLength < 4)
                {
                    throw new ZipException("NTFS Extra data invalid");
                }

                extraData.ReadInt(); // Reserved

                while (extraData.UnreadCount >= 4)
                {
                    int ntfsTag    = extraData.ReadShort();
                    int ntfsLength = extraData.ReadShort();
                    if (ntfsTag == 1)
                    {
                        if (ntfsLength >= 24)
                        {
                            long lastModification = extraData.ReadLong();
                            long lastAccess       = extraData.ReadLong();
                            long createTime       = extraData.ReadLong();

                            DateTime = System.DateTime.FromFileTime(lastModification);
                        }
                        break;
                    }
                    else
                    {
                        // An unknown NTFS tag so simply skip it.
                        extraData.Skip(ntfsLength);
                    }
                }
            }
            else if (extraData.Find(0x5455))
            {
                int length = extraData.ValueLength;
                int flags  = extraData.ReadByte();

                // Can include other times but these are ignored.  Length of data should
                // actually be 1 + 4 * no of bits in flags.
                if (((flags & 1) != 0) && (length >= 5))
                {
                    int iTime = extraData.ReadInt();

                    DateTime = (new System.DateTime(1970, 1, 1, 0, 0, 0).ToUniversalTime() +
                                new TimeSpan(0, 0, 0, iTime, 0)).ToLocalTime();
                }
            }
            if (method == CompressionMethod.WinZipAES)
            {
                ProcessAESExtraData(extraData);
            }
        }
コード例 #6
0
        /// <summary>
        /// Finishes the stream.  This will write the central directory at the
        /// end of the zip file and flush the stream.
        /// </summary>
        /// <remarks>
        /// This is automatically called when the stream is closed.
        /// </remarks>
        /// <exception cref="System.IO.IOException">
        /// An I/O error occurs.
        /// </exception>
        /// <exception cref="ZipException">
        /// Comment exceeds the maximum length<br/>
        /// Entry name exceeds the maximum length
        /// </exception>
        public override void Finish()
        {
            if (entries == null)
            {
                return;
            }

            if (curEntry != null)
            {
                CloseEntry();
            }

            long numEntries  = entries.Count;
            long sizeEntries = 0;

            foreach (ZipEntry entry in entries)
            {
                WriteLeInt(ZipConstants.CentralHeaderSignature);
                WriteLeShort(ZipConstants.VersionMadeBy);
                WriteLeShort(entry.Version);
                WriteLeShort(entry.Flags);
                WriteLeShort((short)entry.CompressionMethodForHeader);
                WriteLeInt((int)entry.DosTime);
                WriteLeInt((int)entry.Crc);

                if (entry.IsZip64Forced() ||
                    (entry.CompressedSize >= uint.MaxValue))
                {
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt((int)entry.CompressedSize);
                }

                if (entry.IsZip64Forced() ||
                    (entry.Size >= uint.MaxValue))
                {
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt((int)entry.Size);
                }

                byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);

                if (name.Length > 0xffff)
                {
                    throw new ZipException("Name too long.");
                }

                ZipExtraData ed = new ZipExtraData(entry.ExtraData);

                if (entry.CentralHeaderRequiresZip64)
                {
                    ed.StartNewEntry();
                    if (entry.IsZip64Forced() ||
                        (entry.Size >= 0xffffffff))
                    {
                        ed.AddLeLong(entry.Size);
                    }

                    if (entry.IsZip64Forced() ||
                        (entry.CompressedSize >= 0xffffffff))
                    {
                        ed.AddLeLong(entry.CompressedSize);
                    }

                    if (entry.Offset >= 0xffffffff)
                    {
                        ed.AddLeLong(entry.Offset);
                    }

                    ed.AddNewEntry(1);
                }
                else
                {
                    ed.Delete(1);
                }

#if !NET_1_1 && !NETCF_2_0
                if (entry.AESKeySize > 0)
                {
                    AddExtraDataAES(entry, ed);
                }
#endif
                byte[] extra = ed.GetEntryData();

                byte[] entryComment =
                    (entry.Comment != null) ?
                    ZipConstants.ConvertToArray(entry.Flags, entry.Comment) :
                    new byte[0];

                if (entryComment.Length > 0xffff)
                {
                    throw new ZipException("Comment too long.");
                }

                WriteLeShort(name.Length);
                WriteLeShort(extra.Length);
                WriteLeShort(entryComment.Length);
                WriteLeShort(0);        // disk number
                WriteLeShort(0);        // internal file attributes
                // external file attributes

                if (entry.ExternalFileAttributes != -1)
                {
                    WriteLeInt(entry.ExternalFileAttributes);
                }
                else
                {
                    if (entry.IsDirectory)
                    {                         // mark entry as directory (from nikolam.AT.perfectinfo.com)
                        WriteLeInt(16);
                    }
                    else
                    {
                        WriteLeInt(0);
                    }
                }

                if (entry.Offset >= uint.MaxValue)
                {
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt((int)entry.Offset);
                }

                if (name.Length > 0)
                {
                    baseOutputStream_.Write(name, 0, name.Length);
                }

                if (extra.Length > 0)
                {
                    baseOutputStream_.Write(extra, 0, extra.Length);
                }

                if (entryComment.Length > 0)
                {
                    baseOutputStream_.Write(entryComment, 0, entryComment.Length);
                }

                sizeEntries += ZipConstants.CentralHeaderBaseSize + name.Length + extra.Length + entryComment.Length;
            }

            using (ZipHelperStream zhs = new ZipHelperStream(baseOutputStream_))
            {
                zhs.WriteEndOfCentralDirectory(numEntries, sizeEntries, offset, zipComment);
            }

            entries = null;
        }
コード例 #7
0
        /// <summary>
        /// Starts a new Zip entry. It automatically closes the previous
        /// entry if present.
        /// All entry elements bar name are optional, but must be correct if present.
        /// If the compression method is stored and the output is not patchable
        /// the compression for that entry is automatically changed to deflate level 0
        /// </summary>
        /// <param name="entry">
        /// the entry.
        /// </param>
        /// <exception cref="System.ArgumentNullException">
        /// if entry passed is null.
        /// </exception>
        /// <exception cref="System.IO.IOException">
        /// if an I/O error occured.
        /// </exception>
        /// <exception cref="System.InvalidOperationException">
        /// if stream was finished
        /// </exception>
        /// <exception cref="ZipException">
        /// Too many entries in the Zip file<br/>
        /// Entry name is too long<br/>
        /// Finish has already been called<br/>
        /// </exception>
        public void PutNextEntry(ZipEntry entry)
        {
            if (entry == null)
            {
                throw new ArgumentNullException("entry");
            }

            if (entries == null)
            {
                throw new InvalidOperationException("ZipOutputStream was finished");
            }

            if (curEntry != null)
            {
                CloseEntry();
            }

            if (entries.Count == int.MaxValue)
            {
                throw new ZipException("Too many entries for Zip file");
            }

            CompressionMethod method = entry.CompressionMethod;
            int compressionLevel     = defaultCompressionLevel;

            // Clear flags that the library manages internally
            entry.Flags     &= (int)GeneralBitFlags.UnicodeText;
            patchEntryHeader = false;

            bool headerInfoAvailable;

            // No need to compress - definitely no data.
            if (entry.Size == 0)
            {
                entry.CompressedSize = entry.Size;
                entry.Crc            = 0;
                method = CompressionMethod.Stored;
                headerInfoAvailable = true;
            }
            else
            {
                headerInfoAvailable = (entry.Size >= 0) && entry.HasCrc;

                // Switch to deflation if storing isnt possible.
                if (method == CompressionMethod.Stored)
                {
                    if (!headerInfoAvailable)
                    {
                        if (!CanPatchEntries)
                        {
                            // Can't patch entries so storing is not possible.
                            method           = CompressionMethod.Deflated;
                            compressionLevel = 0;
                        }
                    }
                    else // entry.size must be > 0
                    {
                        entry.CompressedSize = entry.Size;
                        headerInfoAvailable  = entry.HasCrc;
                    }
                }
            }

            if (headerInfoAvailable == false)
            {
                if (CanPatchEntries == false)
                {
                    // Only way to record size and compressed size is to append a data descriptor
                    // after compressed data.

                    // Stored entries of this form have already been converted to deflating.
                    entry.Flags |= 8;
                }
                else
                {
                    patchEntryHeader = true;
                }
            }

            if (Password != null)
            {
                entry.IsCrypted = true;
                if (entry.Crc < 0)
                {
                    // Need to append a data descriptor as the crc isnt available for use
                    // with encryption, the date is used instead.  Setting the flag
                    // indicates this to the decompressor.
                    entry.Flags |= 8;
                }
            }

            entry.Offset            = offset;
            entry.CompressionMethod = (CompressionMethod)method;

            curMethod    = method;
            sizePatchPos = -1;

            if ((useZip64_ == UseZip64.On) || ((entry.Size < 0) && (useZip64_ == UseZip64.Dynamic)))
            {
                entry.ForceZip64();
            }

            // Write the local file header
            WriteLeInt(ZipConstants.LocalHeaderSignature);

            WriteLeShort(entry.Version);
            WriteLeShort(entry.Flags);
            WriteLeShort((byte)entry.CompressionMethodForHeader);
            WriteLeInt((int)entry.DosTime);

            // TODO: Refactor header writing.  Its done in several places.
            if (headerInfoAvailable == true)
            {
                WriteLeInt((int)entry.Crc);
                if (entry.LocalHeaderRequiresZip64)
                {
                    WriteLeInt(-1);
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
                    WriteLeInt((int)entry.Size);
                }
            }
            else
            {
                if (patchEntryHeader)
                {
                    crcPatchPos = baseOutputStream_.Position;
                }
                WriteLeInt(0);  // Crc

                if (patchEntryHeader)
                {
                    sizePatchPos = baseOutputStream_.Position;
                }

                // For local header both sizes appear in Zip64 Extended Information
                if (entry.LocalHeaderRequiresZip64 || patchEntryHeader)
                {
                    WriteLeInt(-1);
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt(0);      // Compressed size
                    WriteLeInt(0);      // Uncompressed size
                }
            }

            byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);

            if (name.Length > 0xFFFF)
            {
                throw new ZipException("Entry name too long.");
            }

            ZipExtraData ed = new ZipExtraData(entry.ExtraData);

            if (entry.LocalHeaderRequiresZip64)
            {
                ed.StartNewEntry();
                if (headerInfoAvailable)
                {
                    ed.AddLeLong(entry.Size);
                    ed.AddLeLong(entry.CompressedSize);
                }
                else
                {
                    ed.AddLeLong(-1);
                    ed.AddLeLong(-1);
                }
                ed.AddNewEntry(1);

                if (!ed.Find(1))
                {
                    throw new ZipException("Internal error cant find extra data");
                }

                if (patchEntryHeader)
                {
                    sizePatchPos = ed.CurrentReadIndex;
                }
            }
            else
            {
                ed.Delete(1);
            }

#if !NET_1_1 && !NETCF_2_0
            if (entry.AESKeySize > 0)
            {
                AddExtraDataAES(entry, ed);
            }
#endif
            byte[] extra = ed.GetEntryData();

            WriteLeShort(name.Length);
            WriteLeShort(extra.Length);

            if (name.Length > 0)
            {
                baseOutputStream_.Write(name, 0, name.Length);
            }

            if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
            {
                sizePatchPos += baseOutputStream_.Position;
            }

            if (extra.Length > 0)
            {
                baseOutputStream_.Write(extra, 0, extra.Length);
            }

            offset += ZipConstants.LocalHeaderBaseSize + name.Length + extra.Length;
            // Fix offsetOfCentraldir for AES
            if (entry.AESKeySize > 0)
            {
                offset += entry.AESOverheadSize;
            }

            // Activate the entry.
            curEntry = entry;
            crc.Reset();
            if (method == CompressionMethod.Deflated)
            {
                deflater_.Reset();
                deflater_.SetLevel(compressionLevel);
            }
            size = 0;

            if (entry.IsCrypted)
            {
#if !NET_1_1 && !NETCF_2_0
                if (entry.AESKeySize > 0)
                {
                    WriteAESHeader(entry);
                }
                else
#endif
                {
                    if (entry.Crc < 0)
                    {                   // so testing Zip will says its ok
                        WriteEncryptionHeader(entry.DosTime << 16);
                    }
                    else
                    {
                        WriteEncryptionHeader(entry.Crc);
                    }
                }
            }
        }