Ejemplo n.º 1
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.CompressionMethod);
                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);
                }

                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;
        }
Ejemplo n.º 2
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)method);
            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 == true) {
                    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);
            }

            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;

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

            if (entry.IsCrypted == true) {
                if (entry.Crc < 0) {			// so testing Zip will says its ok
                    WriteEncryptionHeader(entry.DosTime << 16);
                } else {
                    WriteEncryptionHeader(entry.Crc);
                }
            }
        }
Ejemplo n.º 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) ) {
                if ( (versionToExtract & 0xff) < ZipConstants.VersionZip64 ) {
                    throw new ZipException("Zip64 Extended information found but version is not valid");
                }

                // 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();
                }
            }
            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 < 8 ) {
                    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();
                }
            }
        }
Ejemplo n.º 4
0
        void WriteLocalEntryHeader(ZipUpdate update)
        {
            ZipEntry entry = update.OutEntry;

            // TODO: Local offset will require adjusting for multi-disk zip files.
            entry.Offset = baseStream_.Position;

            // TODO: Need to clear any entry flags that dont make sense or throw an exception here.
            if (update.Command != UpdateCommand.Copy) {
                if (entry.CompressionMethod == CompressionMethod.Deflated) {
                    if (entry.Size == 0) {
                        // No need to compress - no data.
                        entry.CompressedSize = entry.Size;
                        entry.Crc = 0;
                        entry.CompressionMethod = CompressionMethod.Stored;
                    }
                }
                else if (entry.CompressionMethod == CompressionMethod.Stored) {
                    entry.Flags &= ~(int)GeneralBitFlags.Descriptor;
                }

                if (HaveKeys) {
                    entry.IsCrypted = true;
                    if (entry.Crc < 0) {
                        entry.Flags |= (int)GeneralBitFlags.Descriptor;
                    }
                }
                else {
                    entry.IsCrypted = false;
                }

                switch (useZip64_) {
                    case UseZip64.Dynamic:
                        if (entry.Size < 0) {
                            entry.ForceZip64();
                        }
                        break;

                    case UseZip64.On:
                        entry.ForceZip64();
                        break;

                    case UseZip64.Off:
                        // Do nothing.  The entry itself may be using Zip64 independantly.
                        break;
                }
            }

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

            WriteLEShort(entry.Version);
            WriteLEShort(entry.Flags);

            WriteLEShort((byte)entry.CompressionMethod);
            WriteLEInt(( int )entry.DosTime);

            if ( !entry.HasCrc ) {
                // Note patch address for updating CRC later.
                update.CrcPatchOffset = baseStream_.Position;
                WriteLEInt(( int )0);
            }
            else {
                WriteLEInt(unchecked(( int )entry.Crc));
            }

            if (entry.LocalHeaderRequiresZip64) {
                WriteLEInt(-1);
                WriteLEInt(-1);
            }
            else {
                if ( (entry.CompressedSize < 0) || (entry.Size < 0) ) {
                    update.SizePatchOffset = baseStream_.Position;
                }

                WriteLEInt(( int )entry.CompressedSize);
                WriteLEInt(( int )entry.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();

                // Local entry header always includes size and compressed size.
                // NOTE the order of these fields is reversed when compared to the normal headers!
                ed.AddLeLong(entry.Size);
                ed.AddLeLong(entry.CompressedSize);
                ed.AddNewEntry(1);
            }
            else {
                ed.Delete(1);
            }

            entry.ExtraData = ed.GetEntryData();

            WriteLEShort(name.Length);
            WriteLEShort(entry.ExtraData.Length);

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

            if ( entry.LocalHeaderRequiresZip64 ) {
                if ( !ed.Find(1) ) {
                    throw new ZipException("Internal error cannot find extra data");
                }

                update.SizePatchOffset = baseStream_.Position + ed.CurrentReadIndex;
            }

            if ( entry.ExtraData.Length > 0 ) {
                baseStream_.Write(entry.ExtraData, 0, entry.ExtraData.Length);
            }
        }
Ejemplo n.º 5
0
        int WriteCentralDirectoryHeader(ZipEntry entry)
        {
            if ( entry.CompressedSize < 0 ) {
                throw new ZipException("Attempt to write central directory entry with unknown csize");
            }

            if ( entry.Size < 0 ) {
                throw new ZipException("Attempt to write central directory entry with unknown size");
            }

            if ( entry.Crc < 0 ) {
                throw new ZipException("Attempt to write central directory entry with unknown crc");
            }

            // Write the central file header
            WriteLEInt(ZipConstants.CentralHeaderSignature);

            // Version made by
            WriteLEShort(ZipConstants.VersionMadeBy);

            // Version required to extract
            WriteLEShort(entry.Version);

            WriteLEShort(entry.Flags);

            unchecked {
                WriteLEShort((byte)entry.CompressionMethod);
                WriteLEInt((int)entry.DosTime);
                WriteLEInt((int)entry.Crc);
            }

            if ( (entry.IsZip64Forced()) || (entry.CompressedSize >= 0xffffffff) ) {
                WriteLEInt(-1);
            }
            else {
                WriteLEInt((int)(entry.CompressedSize & 0xffffffff));
            }

            if ( (entry.IsZip64Forced()) || (entry.Size >= 0xffffffff) ) {
                WriteLEInt(-1);
            }
            else {
                WriteLEInt((int)entry.Size);
            }

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

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

            WriteLEShort(name.Length);

            // Central header extra data is different to local header version so regenerate.
            ZipExtraData ed = new ZipExtraData(entry.ExtraData);

            if ( entry.CentralHeaderRequiresZip64 ) {
                ed.StartNewEntry();

                if ( (entry.Size >= 0xffffffff) || (useZip64_ == UseZip64.On) )
                {
                    ed.AddLeLong(entry.Size);
                }

                if ( (entry.CompressedSize >= 0xffffffff) || (useZip64_ == UseZip64.On) )
                {
                    ed.AddLeLong(entry.CompressedSize);
                }

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

                // Number of disk on which this file starts isnt supported and is never written here.
                ed.AddNewEntry(1);
            }
            else {
                // Should have already be done when local header was added.
                ed.Delete(1);
            }

            byte[] centralExtraData = ed.GetEntryData();

            WriteLEShort(centralExtraData.Length);
            WriteLEShort(entry.Comment != null ? entry.Comment.Length : 0);

            WriteLEShort(0);	// disk number
            WriteLEShort(0);	// internal file attributes

            // External file attributes...
            if ( entry.ExternalFileAttributes != -1 ) {
                WriteLEInt(entry.ExternalFileAttributes);
            }
            else {
                if ( entry.IsDirectory ) {
                    WriteLEUint(16);
                }
                else {
                    WriteLEUint(0);
                }
            }

            if ( entry.Offset >= 0xffffffff ) {
                WriteLEUint(0xffffffff);
            }
            else {
                WriteLEUint((uint)(int)entry.Offset);
            }

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

            if ( centralExtraData.Length > 0 ) {
                baseStream_.Write(centralExtraData, 0, centralExtraData.Length);
            }

            byte[] rawComment = (entry.Comment != null) ? Encoding.ASCII.GetBytes(entry.Comment) : new byte[0];

            if ( rawComment.Length > 0 ) {
                baseStream_.Write(rawComment, 0, rawComment.Length);
            }

            return ZipConstants.CentralHeaderBaseSize + name.Length + centralExtraData.Length + rawComment.Length;
        }
Ejemplo n.º 6
0
        /// <summary>
        /// Test a local header against that provided from the central directory
        /// </summary>
        /// <param name="entry">
        /// The entry to test against
        /// </param>
        /// <param name="tests">The type of <see cref="HeaderTest">tests</see> to carry out.</param>
        /// <returns>The offset of the entries data in the file</returns>
        long TestLocalHeader(ZipEntry entry, HeaderTest tests)
        {
            lock(baseStream_)
            {
                bool testHeader = (tests & HeaderTest.Header) != 0;
                bool testData = (tests & HeaderTest.Extract) != 0;

                baseStream_.Seek(offsetOfFirstEntry + entry.Offset, SeekOrigin.Begin);
                if ((int)ReadLEUint() != ZipConstants.LocalHeaderSignature) {
                    throw new ZipException(string.Format("Wrong local header signature @{0:X}", offsetOfFirstEntry + entry.Offset));
                }

                short extractVersion = ( short )ReadLEUshort();
                short localFlags = ( short )ReadLEUshort();
                short compressionMethod = ( short )ReadLEUshort();
                short fileTime = ( short )ReadLEUshort();
                short fileDate = ( short )ReadLEUshort();
                uint crcValue = ReadLEUint();
                long compressedSize = ReadLEUint();
                long size = ReadLEUint();
                int storedNameLength = ReadLEUshort();
                int extraDataLength = ReadLEUshort();

                byte[] nameData = new byte[storedNameLength];
                StreamUtils.ReadFully(baseStream_, nameData);

                byte[] extraData = new byte[extraDataLength];
                StreamUtils.ReadFully(baseStream_, extraData);

                ZipExtraData localExtraData = new ZipExtraData(extraData);

                // Extra data / zip64 checks
                if (localExtraData.Find(1))
                {
                    // TODO Check for tag values being distinct..  Multiple zip64 tags means what?

                    // Zip64 extra data but 'extract version' is too low
                    if (extractVersion < ZipConstants.VersionZip64)
                    {
                        throw new ZipException(
                            string.Format("Extra data contains Zip64 information but version {0}.{1} is not high enough",
                            extractVersion / 10, extractVersion % 10));
                    }

                    // Zip64 extra data but size fields dont indicate its required.
                    if (((uint)size != uint.MaxValue) && ((uint)compressedSize != uint.MaxValue))
                    {
                        throw new ZipException("Entry sizes not correct for Zip64");
                    }

                    size = localExtraData.ReadLong();
                    compressedSize = localExtraData.ReadLong();

                    if ((localFlags & (int)GeneralBitFlags.Descriptor) != 0)
                    {
                        // These may be valid if patched later
                        if ( (size != -1) && (size != entry.Size)) {
                            throw new ZipException("Size invalid for descriptor");
                        }

                        if ((compressedSize != -1) && (compressedSize != entry.CompressedSize)) {
                            throw new ZipException("Compressed size invalid for descriptor");
                        }
                    }
                }
                else
                {
                    // No zip64 extra data but entry requires it.
                    if ((extractVersion >= ZipConstants.VersionZip64) &&
                        (((uint)size == uint.MaxValue) || ((uint)compressedSize == uint.MaxValue)))
                    {
                        throw new ZipException("Required Zip64 extended information missing");
                    }
                }

                if ( testData ) {
                    if ( entry.IsFile ) {
                        if ( !entry.IsCompressionMethodSupported() ) {
                            throw new ZipException("Compression method not supported");
                        }

                        if ( (extractVersion > ZipConstants.VersionMadeBy)
                            || ((extractVersion > 20) && (extractVersion < ZipConstants.VersionZip64)) ) {
                            throw new ZipException(string.Format("Version required to extract this entry not supported ({0})", extractVersion));
                        }

                        if ( (localFlags & ( int )(GeneralBitFlags.Patched | GeneralBitFlags.StrongEncryption | GeneralBitFlags.EnhancedCompress | GeneralBitFlags.HeaderMasked)) != 0 ) {
                            throw new ZipException("The library does not support the zip version required to extract this entry");
                        }
                    }
                }

                if (testHeader)
                {
                    if ((extractVersion <= 63) &&	// Ignore later versions as we dont know about them..
                        (extractVersion != 10) &&
                        (extractVersion != 11) &&
                        (extractVersion != 20) &&
                        (extractVersion != 21) &&
                        (extractVersion != 25) &&
                        (extractVersion != 27) &&
                        (extractVersion != 45) &&
                        (extractVersion != 46) &&
                        (extractVersion != 50) &&
                        (extractVersion != 51) &&
                        (extractVersion != 52) &&
                        (extractVersion != 61) &&
                        (extractVersion != 62) &&
                        (extractVersion != 63)
                        )
                    {
                        throw new ZipException(string.Format("Version required to extract this entry is invalid ({0})", extractVersion));
                    }

                    // Local entry flags dont have reserved bit set on.
                    if ((localFlags & (int)(GeneralBitFlags.ReservedPKware4 | GeneralBitFlags.ReservedPkware14 | GeneralBitFlags.ReservedPkware15)) != 0)
                    {
                        throw new ZipException("Reserved bit flags cannot be set.");
                    }

                    // Encryption requires extract version >= 20
                    if (((localFlags & (int)GeneralBitFlags.Encrypted) != 0) && (extractVersion < 20))
                    {
                        throw new ZipException(string.Format("Version required to extract this entry is too low for encryption ({0})", extractVersion));
                    }

                    // Strong encryption requires encryption flag to be set and extract version >= 50.
                    if ((localFlags & (int)GeneralBitFlags.StrongEncryption) != 0)
                    {
                        if ((localFlags & (int)GeneralBitFlags.Encrypted) == 0)
                        {
                            throw new ZipException("Strong encryption flag set but encryption flag is not set");
                        }

                        if (extractVersion < 50)
                        {
                            throw new ZipException(string.Format("Version required to extract this entry is too low for encryption ({0})", extractVersion));
                        }
                    }

                    // Patched entries require extract version >= 27
                    if (((localFlags & (int)GeneralBitFlags.Patched) != 0) && (extractVersion < 27))
                    {
                        throw new ZipException(string.Format("Patched data requires higher version than ({0})", extractVersion));
                    }

                    // Central header flags match local entry flags.
                    if (localFlags != entry.Flags)
                    {
                        throw new ZipException("Central header/local header flags mismatch");
                    }

                    // Central header compression method matches local entry
                    if (entry.CompressionMethod != (CompressionMethod)compressionMethod)
                    {
                        throw new ZipException("Central header/local header compression method mismatch");
                    }

                    if (entry.Version != extractVersion)
                    {
                        throw new ZipException("Extract version mismatch");
                    }

                    // Strong encryption and extract version match
                    if ((localFlags & (int)GeneralBitFlags.StrongEncryption) != 0)
                    {
                        if (extractVersion < 62)
                        {
                            throw new ZipException("Strong encryption flag set but version not high enough");
                        }
                    }

                    if ((localFlags & (int)GeneralBitFlags.HeaderMasked) != 0)
                    {
                        if ((fileTime != 0) || (fileDate != 0))
                        {
                            throw new ZipException("Header masked set but date/time values non-zero");
                        }
                    }

                    if ((localFlags & (int)GeneralBitFlags.Descriptor) == 0)
                    {
                        if (crcValue != (uint)entry.Crc)
                        {
                            throw new ZipException("Central header/local header crc mismatch");
                        }
                    }

                    // Crc valid for empty entry.
                    // This will also apply to streamed entries where size isnt known and the header cant be patched
                    if ((size == 0) && (compressedSize == 0))
                    {
                        if (crcValue != 0)
                        {
                            throw new ZipException("Invalid CRC for empty entry");
                        }
                    }

                    // TODO: make test more correct...  can't compare lengths as was done originally as this can fail for MBCS strings
                    // Assuming a code page at this point is not valid?  Best is to store the name length in the ZipEntry probably
                    if (entry.Name.Length > storedNameLength)
                    {
                        throw new ZipException("File name length mismatch");
                    }

                    // Name data has already been read convert it and compare.
                    string localName = ZipConstants.ConvertToStringExt(localFlags, nameData);

                    // Central directory and local entry name match
                    if (localName != entry.Name)
                    {
                        throw new ZipException("Central header and local header file name mismatch");
                    }

                    // Directories have zero actual size but can have compressed size
                    if (entry.IsDirectory)
                    {
                        if (size > 0)
                        {
                            throw new ZipException("Directory cannot have size");
                        }

                        // There may be other cases where the compressed size can be greater than this?
                        // If so until details are known we will be strict.
                        if (entry.IsCrypted)
                        {
                            if (compressedSize > ZipConstants.CryptoHeaderSize + 2)
                            {
                                throw new ZipException("Directory compressed size invalid");
                            }
                        }
                        else if (compressedSize > 2)
                        {
                            // When not compressed the directory size can validly be 2 bytes
                            // if the true size wasnt known when data was originally being written.
                            // NOTE: Versions of the library 0.85.4 and earlier always added 2 bytes
                            throw new ZipException("Directory compressed size invalid");
                        }
                    }

                    if (!ZipNameTransform.IsValidName(localName, true))
                    {
                        throw new ZipException("Name is invalid");
                    }
                }

                // Tests that apply to both data and header.

                // Size can be verified only if it is known in the local header.
                // it will always be known in the central header.
                if (((localFlags & (int)GeneralBitFlags.Descriptor) == 0) ||
                    ((size > 0) || (compressedSize > 0))) {

                    if (size != entry.Size) {
                        throw new ZipException(
                            string.Format("Size mismatch between central header({0}) and local header({1})",
                                entry.Size, size));
                    }

                    if (compressedSize != entry.CompressedSize) {
                        throw new ZipException(
                            string.Format("Compressed size mismatch between central header({0}) and local header({1})",
                            entry.CompressedSize, compressedSize));
                    }
                }

                int extraLength = storedNameLength + extraDataLength;
                return offsetOfFirstEntry + entry.Offset + ZipConstants.LocalHeaderBaseSize + extraLength;
            }
        }
Ejemplo n.º 7
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);
            }
        }