// Zip.cs
//
// Copyright (c) 2006, 2007 Microsoft Corporation. All rights reserved.
//
//
// This class library reads and writes zip files, according to the format
// described by pkware, at:
// http://www.pkware.com/business_and_developers/developer/popups/appnote.txt
//
// This implementation is based on the
// System.IO.Compression.DeflateStream base class in the .NET Framework
// v2.0 base class library.
//
// There are other Zip class libraries available. For example, it is
// possible to read and write zip files within .NET via the J# runtime.
// But some people don't like to install the extra DLL. Also, there is
// a 3rd party LGPL-based (or is it GPL?) library called SharpZipLib,
// which works, in both .NET 1.1 and .NET 2.0. But some people don't
// like the GPL. Finally, there are commercial tools (From ComponentOne,
// XCeed, etc). But some people don't want to incur the cost.
//
// This alternative implementation is not GPL licensed, is free of cost,
// and does not require J#. It does require .NET 2.0 (for the DeflateStream
// class).
//
// This code is released under the Microsoft Permissive License of OCtober 2006.
// See the License.txt for details.
//
// Notes:
// This is at best a cripppled and naive implementation.
//
// Bugs:
// 1. does not do 0..9 compression levels (not supported by DeflateStream)
// 2. does not do encryption
// 3. no support for reading or writing multi-disk zip archives
// 4. no support for file comments or archive comments
// 5. does not stream as it compresses; all compressed data is kept in memory.
// 6. no support for double-byte chars in filenames
// 7. no support for asynchronous operation
//
// But it does read and write basic zip files, and it gets reasonable compression.
//
// NB: PKWare's zip specification states:
//
// ----------------------
// PKWARE is committed to the interoperability and advancement of the
// .ZIP format. PKWARE offers a free license for certain technological
// aspects described above under certain restrictions and conditions.
// However, the use or implementation in a product of certain technological
// aspects set forth in the current APPNOTE, including those with regard to
// strong encryption or patching, requires a license from PKWARE. Please
// contact PKWARE with regard to acquiring a license.
// ----------------------
//
// Fri, 31 Mar 2006 14:43
//
// update Thu, 22 Feb 2007 19:03
// Fixed a problem with archives that had bit-3 (0x0008) set,
// where the CRC, Compressed Size, and Uncompressed size
// actually followed the compressed file data.
//
using System;
namespace ionic.utils.zip
{
class Shared
{
protected internal static string StringFromBuffer(byte[] buf, int start, int maxlength)
{
int i;
char[] c = new char[maxlength];
for (i = 0; (i < maxlength) && (i < buf.Length) && (buf[i] != 0); i++)
{
c[i] = (char)buf[i]; // System.BitConverter.ToChar(buf, start+i*2);
}
string s = new System.String(c, 0, i);
return s;
}
protected internal static int ReadSignature(System.IO.Stream s)
{
int n = 0;
byte[] sig = new byte[4];
n = s.Read(sig, 0, sig.Length);
if (n != sig.Length) throw new Exception("Could not read signature - no data!");
int signature = (((sig[3] * 256 + sig[2]) * 256) + sig[1]) * 256 + sig[0];
return signature;
}
protected internal static long FindSignature(System.IO.Stream s, int SignatureToFind)
{
long startingPosition = s.Position;
int BATCH_SIZE = 1024;
byte[] targetBytes = new byte[4];
targetBytes[0] = (byte) (SignatureToFind >> 24);
targetBytes[1] = (byte) ((SignatureToFind & 0x00FF0000) >> 16);
targetBytes[2] = (byte) ((SignatureToFind & 0x0000FF00) >> 8);
targetBytes[3] = (byte) (SignatureToFind & 0x000000FF);
byte[] batch = new byte[BATCH_SIZE];
int n = 0;
bool success = false;
do
{
n = s.Read(batch, 0, batch.Length);
if (n != 0)
{
for (int i = 0; i < n; i++)
{
if (batch[i] == targetBytes[3])
{
s.Seek(i - n, System.IO.SeekOrigin.Current);
int sig = ReadSignature(s);
success = (sig == SignatureToFind);
if (!success) s.Seek(-3, System.IO.SeekOrigin.Current);
break; // out of for loop
}
}
}
else break;
if (success) break;
} while (true);
if (!success)
{
s.Seek(startingPosition, System.IO.SeekOrigin.Begin);
return -1; // or throw?
}
// subtract 4 for the signature.
long bytesRead = (s.Position - startingPosition) - 4 ;
// number of bytes read, should be the same as compressed size of file
return bytesRead;
}
protected internal static DateTime PackedToDateTime(Int32 packedDateTime)
{
Int16 packedTime = (Int16)(packedDateTime & 0x0000ffff);
Int16 packedDate = (Int16)((packedDateTime & 0xffff0000) >> 16);
int year = 1980 + ((packedDate & 0xFE00) >> 9);
int month = (packedDate & 0x01E0) >> 5;
int day = packedDate & 0x001F;
int hour = (packedTime & 0xF800) >> 11;
int minute = (packedTime & 0x07E0) >> 5;
int second = packedTime & 0x001F;
DateTime d = System.DateTime.Now;
try { d = new System.DateTime(year, month, day, hour, minute, second, 0); }
catch
{
Console.Write("\nInvalid date/time?:\nyear: {0} ", year);
Console.Write("month: {0} ", month);
Console.WriteLine("day: {0} ", day);
Console.WriteLine("HH:MM:SS= {0}:{1}:{2}", hour, minute, second);
}
return d;
}
protected internal static Int32 DateTimeToPacked(DateTime time)
{
UInt16 packedDate = (UInt16)((time.Day & 0x0000001F) | ((time.Month << 5) & 0x000001E0) | (((time.Year - 1980) << 9) & 0x0000FE00));
UInt16 packedTime = (UInt16)((time.Second & 0x0000001F) | ((time.Minute << 5) & 0x000007E0) | ((time.Hour << 11) & 0x0000F800));
return (Int32)(((UInt32)(packedDate << 16)) | packedTime);
}
}
public class ZipDirEntry
{
internal const int ZipDirEntrySignature = 0x02014b50;
private bool _Debug = false;
private ZipDirEntry() { }
private DateTime _LastModified;
public DateTime LastModified
{
get { return _LastModified; }
}
private string _FileName;
public string FileName
{
get { return _FileName; }
}
private string _Comment;
public string Comment
{
get { return _Comment; }
}
private Int16 _VersionMadeBy;
public Int16 VersionMadeBy
{
get { return _VersionMadeBy; }
}
private Int16 _VersionNeeded;
public Int16 VersionNeeded
{
get { return _VersionNeeded; }
}
private Int16 _CompressionMethod;
public Int16 CompressionMethod
{
get { return _CompressionMethod; }
}
private Int32 _CompressedSize;
public Int32 CompressedSize
{
get { return _CompressedSize; }
}
private Int32 _UncompressedSize;
public Int32 UncompressedSize
{
get { return _UncompressedSize; }
}
public Double CompressionRatio
{
get
{
return 100 * (1.0 - (1.0 * CompressedSize) / (1.0 * UncompressedSize));
}
}
private Int16 _BitField;
private Int32 _LastModDateTime;
private Int32 _Crc32;
private byte[] _Extra;
internal ZipDirEntry(ZipEntry ze) { }
public static ZipDirEntry Read(System.IO.Stream s)
{
return Read(s, false);
}
public static ZipDirEntry Read(System.IO.Stream s, bool TurnOnDebug)
{
int signature = ionic.utils.zip.Shared.ReadSignature(s);
// return null if this is not a local file header signature
if (SignatureIsNotValid(signature))
{
s.Seek(-4, System.IO.SeekOrigin.Current);
if (TurnOnDebug) System.Console.WriteLine(" ZipDirEntry::Read(): Bad signature ({0:X8}) at position {1}", signature, s.Position);
return null;
}
byte[] block = new byte[42];
int n = s.Read(block, 0, block.Length);
if (n != block.Length) return null;
int i = 0;
ZipDirEntry zde = new ZipDirEntry();
zde._Debug = TurnOnDebug;
zde._VersionMadeBy = (short)(block[i++] + block[i++] * 256);
zde._VersionNeeded = (short)(block[i++] + block[i++] * 256);
zde._BitField = (short)(block[i++] + block[i++] * 256);
zde._CompressionMethod = (short)(block[i++] + block[i++] * 256);
zde._LastModDateTime = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
zde._Crc32 = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
zde._CompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
zde._UncompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
zde._LastModified = ionic.utils.zip.Shared.PackedToDateTime(zde._LastModDateTime);
Int16 filenameLength = (short)(block[i++] + block[i++] * 256);
Int16 extraFieldLength = (short)(block[i++] + block[i++] * 256);
Int16 commentLength = (short)(block[i++] + block[i++] * 256);
Int16 diskNumber = (short)(block[i++] + block[i++] * 256);
Int16 internalFileAttrs = (short)(block[i++] + block[i++] * 256);
Int32 externalFileAttrs = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
Int32 Offset = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
block = new byte[filenameLength];
n = s.Read(block, 0, block.Length);
zde._FileName = ionic.utils.zip.Shared.StringFromBuffer(block, 0, block.Length);
zde._Extra = new byte[extraFieldLength];
n = s.Read(zde._Extra, 0, zde._Extra.Length);
block = new byte[commentLength];
n = s.Read(block, 0, block.Length);
zde._Comment = ionic.utils.zip.Shared.StringFromBuffer(block, 0, block.Length);
return zde;
}
private static bool SignatureIsNotValid(int signature)
{
return (signature != ZipDirEntrySignature);
}
}
public class ZipEntry
{
private const int ZipEntrySignature = 0x04034b50;
private const int ZipEntryDataDescriptorSignature= 0x08074b50;
private bool _Debug = false;
private DateTime _LastModified;
public DateTime LastModified
{
get { return _LastModified; }
}
private string _FileName;
public string FileName
{
get { return _FileName; }
}
private Int16 _VersionNeeded;
public Int16 VersionNeeded
{
get { return _VersionNeeded; }
}
private Int16 _BitField;
public Int16 BitField
{
get { return _BitField; }
}
private Int16 _CompressionMethod;
public Int16 CompressionMethod
{
get { return _CompressionMethod; }
}
private Int32 _CompressedSize;
public Int32 CompressedSize
{
get { return _CompressedSize; }
}
private Int32 _UncompressedSize;
public Int32 UncompressedSize
{
get { return _UncompressedSize; }
}
public Double CompressionRatio
{
get
{
return 100 * (1.0 - (1.0 * CompressedSize) / (1.0 * UncompressedSize));
}
}
private Int32 _LastModDateTime;
private Int32 _Crc32;
private byte[] _Extra;
private byte[] __filedata;
private byte[] _FileData
{
get
{
if (__filedata == null)
{
}
return __filedata;
}
}
private System.IO.MemoryStream _UnderlyingMemoryStream;
private System.IO.Compression.DeflateStream _CompressedStream;
private System.IO.Compression.DeflateStream CompressedStream
{
get
{
if (_CompressedStream == null)
{
_UnderlyingMemoryStream = new System.IO.MemoryStream();
bool LeaveUnderlyingStreamOpen = true;
_CompressedStream = new System.IO.Compression.DeflateStream(_UnderlyingMemoryStream,
System.IO.Compression.CompressionMode.Compress,
LeaveUnderlyingStreamOpen);
}
return _CompressedStream;
}
}
private byte[] _header;
internal byte[] Header
{
get
{
return _header;
}
}
private int _RelativeOffsetOfHeader;
private static bool ReadHeader(System.IO.Stream s, ZipEntry ze)
{
int signature = ionic.utils.zip.Shared.ReadSignature(s);
// return null if this is not a local file header signature
if (SignatureIsNotValid(signature))
{
s.Seek(-4, System.IO.SeekOrigin.Current);
if (ze._Debug) System.Console.WriteLine(" ZipEntry::Read(): Bad signature ({0:X8}) at position {1}", signature, s.Position);
return false;
}
byte[] block = new byte[26];
int n = s.Read(block, 0, block.Length);
if (n != block.Length) return false;
int i = 0;
ze._VersionNeeded = (short)(block[i++] + block[i++] * 256);
ze._BitField = (short)(block[i++] + block[i++] * 256);
ze._CompressionMethod = (short)(block[i++] + block[i++] * 256);
ze._LastModDateTime = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
// the PKZIP spec says that if bit 3 is set (0x0008), then the CRC, Compressed size, and uncompressed size
// come directly after the file data. The only way to find it is to scan the zip archive for the signature of
// the Data Descriptor, and presume that that signature does not appear in the (compressed) data of the compressed file.
if ((ze._BitField & 0x0008) != 0x0008)
{
ze._Crc32 = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
ze._CompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
ze._UncompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
}
else
{
// the CRC, compressed size, and uncompressed size are stored later in the stream.
// here, we advance the pointer.
i += 12;
}
Int16 filenameLength = (short)(block[i++] + block[i++] * 256);
Int16 extraFieldLength = (short)(block[i++] + block[i++] * 256);
block = new byte[filenameLength];
n = s.Read(block, 0, block.Length);
ze._FileName = ionic.utils.zip.Shared.StringFromBuffer(block, 0, block.Length);
ze._Extra = new byte[extraFieldLength];
n = s.Read(ze._Extra, 0, ze._Extra.Length);
// transform the time data into something usable
ze._LastModified = ionic.utils.zip.Shared.PackedToDateTime(ze._LastModDateTime);
// actually get the compressed size and CRC if necessary
if ((ze._BitField & 0x0008) == 0x0008)
{
long posn = s.Position;
long SizeOfDataRead = ionic.utils.zip.Shared.FindSignature(s, ZipEntryDataDescriptorSignature);
if (SizeOfDataRead == -1) return false;
// read 3x 4-byte fields (CRC, Compressed Size, Uncompressed Size)
block = new byte[12];
n = s.Read(block, 0, block.Length);
if (n != 12) return false;
i = 0;
ze._Crc32 = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
ze._CompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
ze._UncompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
if (SizeOfDataRead != ze._CompressedSize)
throw new Exception("Data format error (bit 3 is set)");
// seek back to previous position, to read file data
s.Seek(posn, System.IO.SeekOrigin.Begin);
}
return true;
}
private static bool SignatureIsNotValid(int signature)
{
return (signature != ZipEntrySignature);
}
public static ZipEntry Read(System.IO.Stream s)
{
return Read(s, false);
}
public static ZipEntry Read(System.IO.Stream s, bool TurnOnDebug)
{
ZipEntry entry = new ZipEntry();
entry._Debug = TurnOnDebug;
if (!ReadHeader(s, entry)) return null;
entry.__filedata = new byte[entry.CompressedSize];
int n = s.Read(entry._FileData, 0, entry._FileData.Length);
if (n != entry._FileData.Length)
{
throw new Exception("badly formatted zip file.");
}
// finally, seek past the (already read) Data descriptor if necessary
if ((entry._BitField & 0x0008) == 0x0008)
{
s.Seek(16, System.IO.SeekOrigin.Current);
}
return entry;
}
internal static ZipEntry Create(String filename)
{
ZipEntry entry = new ZipEntry();
entry._FileName = filename;
entry._LastModified = System.IO.File.GetLastWriteTime(filename);
if (entry._LastModified.IsDaylightSavingTime())
{
System.DateTime AdjustedTime = entry._LastModified - new System.TimeSpan(1, 0, 0);
entry._LastModDateTime = ionic.utils.zip.Shared.DateTimeToPacked(AdjustedTime);
}
else
entry._LastModDateTime = ionic.utils.zip.Shared.DateTimeToPacked(entry._LastModified);
// we don't actually slurp in the file until the caller invokes Write on this entry.
return entry;
}
public void Extract()
{
Extract(".");
}
public void Extract(System.IO.Stream s)
{
Extract(null, s);
}
public void Extract(string basedir)
{
Extract(basedir, null);
}
// pass in either basdir or s, but not both.
private void Extract(string basedir, System.IO.Stream s)
{
string TargetFile = null;
if (basedir != null)
{
TargetFile = System.IO.Path.Combine(basedir, FileName);
// check if a directory
if (FileName.EndsWith("/"))
{
if (!System.IO.Directory.Exists(TargetFile))
System.IO.Directory.CreateDirectory(TargetFile);
return;
}
}
else if (s != null)
{
if (FileName.EndsWith("/"))
// extract a directory to streamwriter? nothing to do!
return;
}
else throw new Exception("Invalid input.");
using (System.IO.MemoryStream memstream = new System.IO.MemoryStream(_FileData))
{
System.IO.Stream input = null;
try
{
if (CompressedSize == UncompressedSize)
{
// the System.IO.Compression.DeflateStream class does not handle uncompressed data.
// so if an entry is not compressed, then we just translate the bytes directly.
input = memstream;
}
else
{
input = new System.IO.Compression.DeflateStream(memstream, System.IO.Compression.CompressionMode.Decompress);
}
if (TargetFile != null)
{
// ensure the target path exists
if (!System.IO.Directory.Exists(System.IO.Path.GetDirectoryName(TargetFile)))
{
System.IO.Directory.CreateDirectory(System.IO.Path.GetDirectoryName(TargetFile));
}
}
System.IO.Stream output = null;
try
{
if (TargetFile != null)
output = new System.IO.FileStream(TargetFile, System.IO.FileMode.CreateNew);
else
output = s;
byte[] bytes = new byte[4096];
int n;
if (_Debug)
{
Console.WriteLine("{0}: _FileData.Length= {1}", TargetFile, _FileData.Length);
Console.WriteLine("{0}: memstream.Position: {1}", TargetFile, memstream.Position);
n = _FileData.Length;
if (n > 1000)
{
n = 500;
Console.WriteLine("{0}: truncating dump from {1} to {2} bytes...", TargetFile, _FileData.Length, n);
}
for (int j = 0; j < n; j += 2)
{
if ((j > 0) && (j % 40 == 0))
System.Console.WriteLine();
System.Console.Write(" {0:X2}", _FileData[j]);
if (j + 1 < n)
System.Console.Write("{0:X2}", _FileData[j + 1]);
}
System.Console.WriteLine("\n");
}
n = 1; // anything non-zero
while (n != 0)
{
if (_Debug) Console.WriteLine("{0}: about to read...", TargetFile);
n = input.Read(bytes, 0, bytes.Length);
if (_Debug) Console.WriteLine("{0}: got {1} bytes", TargetFile, n);
if (n > 0)
{
if (_Debug) Console.WriteLine("{0}: about to write...", TargetFile);
output.Write(bytes, 0, n);
}
}
}
finally
{
// we only close the output stream if we opened it.
if ((output != null) && (TargetFile != null))
{
output.Close();
output.Dispose();
}
}
if (TargetFile != null)
{
// We may have to adjust the last modified time to compensate
// for differences in how the .NET Base Class Library deals
// with daylight saving time (DST) versus how the Windows
// filesystem deals with daylight saving time.
if (LastModified.IsDaylightSavingTime())
{
DateTime AdjustedLastModified = LastModified + new System.TimeSpan(1, 0, 0);
System.IO.File.SetLastWriteTime(TargetFile, AdjustedLastModified);
}
else
System.IO.File.SetLastWriteTime(TargetFile, LastModified);
}
}
finally
{
// we cannot use using() here because in some cases we do not want to Dispose the stream
if ((input != null) && (input != memstream))
{
input.Close();
input.Dispose();
}
}
}
}
internal void WriteCentralDirectoryEntry(System.IO.Stream s)
{
byte[] bytes = new byte[4096];
int i = 0;
// signature
bytes[i++] = (byte)(ZipDirEntry.ZipDirEntrySignature & 0x000000FF);
bytes[i++] = (byte)((ZipDirEntry.ZipDirEntrySignature & 0x0000FF00) >> 8);
bytes[i++] = (byte)((ZipDirEntry.ZipDirEntrySignature & 0x00FF0000) >> 16);
bytes[i++] = (byte)((ZipDirEntry.ZipDirEntrySignature & 0xFF000000) >> 24);
// Version Made By
bytes[i++] = Header[4];
bytes[i++] = Header[5];
// Version Needed, Bitfield, compression method, lastmod,
// crc, sizes, filename length and extra field length -
// are all the same as the local file header. So just copy them
int j = 0;
for (j = 0; j < 26; j++)
bytes[i + j] = Header[4 + j];
i += j; // positioned at next available byte
// File Comment Length
bytes[i++] = 0;
bytes[i++] = 0;
// Disk number start
bytes[i++] = 0;
bytes[i++] = 0;
// internal file attrs
// TODO: figure out what is required here.
bytes[i++] = 1;
bytes[i++] = 0;
// external file attrs
// TODO: figure out what is required here.
bytes[i++] = 0x20;
bytes[i++] = 0;
bytes[i++] = 0xb6;
bytes[i++] = 0x81;
// relative offset of local header (I think this can be zero)
bytes[i++] = (byte)(_RelativeOffsetOfHeader & 0x000000FF);
bytes[i++] = (byte)((_RelativeOffsetOfHeader & 0x0000FF00) >> 8);
bytes[i++] = (byte)((_RelativeOffsetOfHeader & 0x00FF0000) >> 16);
bytes[i++] = (byte)((_RelativeOffsetOfHeader & 0xFF000000) >> 24);
if (_Debug) System.Console.WriteLine("\ninserting filename into CDS: (length= {0})", Header.Length - 30);
// actual filename (starts at offset 34 in header)
for (j = 0; j < Header.Length - 30; j++)
{
bytes[i + j] = Header[30 + j];
if (_Debug) System.Console.Write(" {0:X2}", bytes[i + j]);
}
if (_Debug) System.Console.WriteLine();
i += j;
s.Write(bytes, 0, i);
}
private void WriteHeader(System.IO.Stream s, byte[] bytes)
{
// write the header info
int i = 0;
// signature
bytes[i++] = (byte)(ZipEntrySignature & 0x000000FF);
bytes[i++] = (byte)((ZipEntrySignature & 0x0000FF00) >> 8);
bytes[i++] = (byte)((ZipEntrySignature & 0x00FF0000) >> 16);
bytes[i++] = (byte)((ZipEntrySignature & 0xFF000000) >> 24);
// version needed
Int16 FixedVersionNeeded = 0x14; // from examining existing zip files
bytes[i++] = (byte)(FixedVersionNeeded & 0x00FF);
bytes[i++] = (byte)((FixedVersionNeeded & 0xFF00) >> 8);
// bitfield
Int16 BitField = 0x00; // from examining existing zip files
bytes[i++] = (byte)(BitField & 0x00FF);
bytes[i++] = (byte)((BitField & 0xFF00) >> 8);
// compression method
Int16 CompressionMethod = 0x08; // 0x08 = Deflate
bytes[i++] = (byte)(CompressionMethod & 0x00FF);
bytes[i++] = (byte)((CompressionMethod & 0xFF00) >> 8);
// LastMod
bytes[i++] = (byte)(_LastModDateTime & 0x000000FF);
bytes[i++] = (byte)((_LastModDateTime & 0x0000FF00) >> 8);
bytes[i++] = (byte)((_LastModDateTime & 0x00FF0000) >> 16);
bytes[i++] = (byte)((_LastModDateTime & 0xFF000000) >> 24);
// CRC32 (Int32)
CRC32 crc32 = new CRC32();
UInt32 crc = 0;
using (System.IO.Stream input = System.IO.File.OpenRead(FileName))
{
crc = crc32.GetCrc32AndCopy(input, CompressedStream);
}
CompressedStream.Close(); // to get the footer bytes written to the underlying stream
bytes[i++] = (byte)(crc & 0x000000FF);
bytes[i++] = (byte)((crc & 0x0000FF00) >> 8);
bytes[i++] = (byte)((crc & 0x00FF0000) >> 16);
bytes[i++] = (byte)((crc & 0xFF000000) >> 24);
// CompressedSize (Int32)
Int32 isz = (Int32)_UnderlyingMemoryStream.Length;
UInt32 sz = (UInt32)isz;
bytes[i++] = (byte)(sz & 0x000000FF);
bytes[i++] = (byte)((sz & 0x0000FF00) >> 8);
bytes[i++] = (byte)((sz & 0x00FF0000) >> 16);
bytes[i++] = (byte)((sz & 0xFF000000) >> 24);
// UncompressedSize (Int32)
if (_Debug) System.Console.WriteLine("Uncompressed Size: {0}", crc32.TotalBytesRead);
bytes[i++] = (byte)(crc32.TotalBytesRead & 0x000000FF);
bytes[i++] = (byte)((crc32.TotalBytesRead & 0x0000FF00) >> 8);
bytes[i++] = (byte)((crc32.TotalBytesRead & 0x00FF0000) >> 16);
bytes[i++] = (byte)((crc32.TotalBytesRead & 0xFF000000) >> 24);
// filename length (Int16)
Int16 length = (Int16)FileName.Length;
bytes[i++] = (byte)(length & 0x00FF);
bytes[i++] = (byte)((length & 0xFF00) >> 8);
// extra field length (short)
Int16 ExtraFieldLength = 0x00;
bytes[i++] = (byte)(ExtraFieldLength & 0x00FF);
bytes[i++] = (byte)((ExtraFieldLength & 0xFF00) >> 8);
// actual filename
char[] c = FileName.ToCharArray();
int j = 0;
if (_Debug)
{
System.Console.WriteLine("local header: writing filename, {0} chars", c.Length);
System.Console.WriteLine("starting offset={0}", i);
}
for (j = 0; (j < c.Length) && (i + j < bytes.Length); j++)
{
bytes[i + j] = System.BitConverter.GetBytes(c[j])[0];
if (_Debug) System.Console.Write(" {0:X2}", bytes[i + j]);
}
if (_Debug) System.Console.WriteLine();
i += j;
// extra field (we always write null in this implementation)
// ;;
// remember the file offset of this header
_RelativeOffsetOfHeader = (int)s.Length;
if (_Debug)
{
System.Console.WriteLine("\nAll header data:");
for (j = 0; j < i; j++)
System.Console.Write(" {0:X2}", bytes[j]);
System.Console.WriteLine();
}
// finally, write the header to the stream
s.Write(bytes, 0, i);
// preserve this header data for use with the central directory structure.
_header = new byte[i];
if (_Debug) System.Console.WriteLine("preserving header of {0} bytes", _header.Length);
for (j = 0; j < i; j++)
_header[j] = bytes[j];
}
internal void Write(System.IO.Stream s)
{
byte[] bytes = new byte[4096];
int n;
// write the header:
WriteHeader(s, bytes);
// write the actual file data:
_UnderlyingMemoryStream.Position = 0;
if (_Debug)
{
Console.WriteLine("{0}: writing compressed data to zipfile...", FileName);
Console.WriteLine("{0}: total data length: {1}", FileName, _UnderlyingMemoryStream.Length);
}
while ((n = _UnderlyingMemoryStream.Read(bytes, 0, bytes.Length)) != 0)
{
if (_Debug)
{
Console.WriteLine("{0}: transferring {1} bytes...", FileName, n);
for (int j = 0; j < n; j += 2)
{
if ((j > 0) && (j % 40 == 0))
System.Console.WriteLine();
System.Console.Write(" {0:X2}", bytes[j]);
if (j + 1 < n)
System.Console.Write("{0:X2}", bytes[j + 1]);
}
System.Console.WriteLine("\n");
}
s.Write(bytes, 0, n);
}
//_CompressedStream.Close();
//_CompressedStream= null;
_UnderlyingMemoryStream.Close();
_UnderlyingMemoryStream = null;
}
}
public class ZipFile : System.Collections.Generic.IEnumerable<ZipEntry>,
IDisposable
{
private string _name;
public string Name
{
get { return _name; }
}
private System.IO.Stream ReadStream
{
get
{
if (_readstream == null)
{
_readstream = System.IO.File.OpenRead(_name);
}
return _readstream;
}
}
private System.IO.FileStream WriteStream
{
get
{
if (_writestream == null)
{
_writestream = new System.IO.FileStream(_name, System.IO.FileMode.CreateNew);
}
return _writestream;
}
}
private ZipFile() { }
#region For Writing Zip Files
public ZipFile(string NewZipFileName)
{
// create a new zipfile
_name = NewZipFileName;
if (System.IO.File.Exists(_name))
throw new System.Exception(String.Format("That file ({0}) already exists.", NewZipFileName));
_entries = new System.Collections.Generic.List<ZipEntry>();
}
public void AddItem(string FileOrDirectoryName)
{
AddItem(FileOrDirectoryName, false);
}
public void AddItem(string FileOrDirectoryName, bool WantVerbose)
{
if (System.IO.File.Exists(FileOrDirectoryName))
AddFile(FileOrDirectoryName, WantVerbose);
else if (System.IO.Directory.Exists(FileOrDirectoryName))
AddDirectory(FileOrDirectoryName, WantVerbose);
else
throw new Exception(String.Format("That file or directory ({0}) does not exist!", FileOrDirectoryName));
}
public void AddFile(string FileName)
{
AddFile(FileName, false);
}
public void AddFile(string FileName, bool WantVerbose)
{
ZipEntry ze = ZipEntry.Create(FileName);
if (WantVerbose) Console.WriteLine("adding {0}...", FileName);
_entries.Add(ze);
}
public void AddDirectory(string DirectoryName)
{
AddDirectory(DirectoryName, false);
}
public void AddDirectory(string DirectoryName, bool WantVerbose)
{
String[] filenames = System.IO.Directory.GetFiles(DirectoryName);
foreach (String filename in filenames)
{
if (WantVerbose) Console.WriteLine("adding {0}...", filename);
AddFile(filename);
}
String[] dirnames = System.IO.Directory.GetDirectories(DirectoryName);
foreach (String dir in dirnames)
{
AddDirectory(dir, WantVerbose);
}
}
public void Save()
{
// an entry for each file
foreach (ZipEntry e in _entries)
{
e.Write(WriteStream);
}
WriteCentralDirectoryStructure();
WriteStream.Close();
_writestream = null;
}
private void WriteCentralDirectoryStructure()
{
// the central directory structure
long Start = WriteStream.Length;
foreach (ZipEntry e in _entries)
{
e.WriteCentralDirectoryEntry(WriteStream);
}
long Finish = WriteStream.Length;
// now, the footer
WriteCentralDirectoryFooter(Start, Finish);
}
private void WriteCentralDirectoryFooter(long StartOfCentralDirectory, long EndOfCentralDirectory)
{
byte[] bytes = new byte[1024];
int i = 0;
// signature
UInt32 EndOfCentralDirectorySignature = 0x06054b50;
bytes[i++] = (byte)(EndOfCentralDirectorySignature & 0x000000FF);
bytes[i++] = (byte)((EndOfCentralDirectorySignature & 0x0000FF00) >> 8);
bytes[i++] = (byte)((EndOfCentralDirectorySignature & 0x00FF0000) >> 16);
bytes[i++] = (byte)((EndOfCentralDirectorySignature & 0xFF000000) >> 24);
// number of this disk
bytes[i++] = 0;
bytes[i++] = 0;
// number of the disk with the start of the central directory
bytes[i++] = 0;
bytes[i++] = 0;
// total number of entries in the central dir on this disk
bytes[i++] = (byte)(_entries.Count & 0x00FF);
bytes[i++] = (byte)((_entries.Count & 0xFF00) >> 8);
// total number of entries in the central directory
bytes[i++] = (byte)(_entries.Count & 0x00FF);
bytes[i++] = (byte)((_entries.Count & 0xFF00) >> 8);
// size of the central directory
Int32 SizeOfCentralDirectory = (Int32)(EndOfCentralDirectory - StartOfCentralDirectory);
bytes[i++] = (byte)(SizeOfCentralDirectory & 0x000000FF);
bytes[i++] = (byte)((SizeOfCentralDirectory & 0x0000FF00) >> 8);
bytes[i++] = (byte)((SizeOfCentralDirectory & 0x00FF0000) >> 16);
bytes[i++] = (byte)((SizeOfCentralDirectory & 0xFF000000) >> 24);
// offset of the start of the central directory
Int32 StartOffset = (Int32)StartOfCentralDirectory; // cast down from Long
bytes[i++] = (byte)(StartOffset & 0x000000FF);
bytes[i++] = (byte)((StartOffset & 0x0000FF00) >> 8);
bytes[i++] = (byte)((StartOffset & 0x00FF0000) >> 16);
bytes[i++] = (byte)((StartOffset & 0xFF000000) >> 24);
// zip comment length
bytes[i++] = 0;
bytes[i++] = 0;
WriteStream.Write(bytes, 0, i);
}
#endregion
#region For Reading Zip Files
/// <summary>
/// This will throw if the zipfile does not exist.
/// </summary>
public static ZipFile Read(string zipfilename)
{
return Read(zipfilename, false);
}
/// <summary>
/// This will throw if the zipfile does not exist.
/// </summary>
public static ZipFile Read(string zipfilename, bool TurnOnDebug)
{
ZipFile zf = new ZipFile();
zf._Debug = TurnOnDebug;
zf._name = zipfilename;
zf._entries = new System.Collections.Generic.List<ZipEntry>();
ZipEntry e;
while ((e = ZipEntry.Read(zf.ReadStream, zf._Debug)) != null)
{
if (zf._Debug) System.Console.WriteLine(" ZipFile::Read(): ZipEntry: {0}", e.FileName);
zf._entries.Add(e);
}
// read the zipfile's central directory structure here.
zf._direntries = new System.Collections.Generic.List<ZipDirEntry>();
ZipDirEntry de;
while ((de = ZipDirEntry.Read(zf.ReadStream, zf._Debug)) != null)
{
if (zf._Debug) System.Console.WriteLine(" ZipFile::Read(): ZipDirEntry: {0}", de.FileName);
zf._direntries.Add(de);
}
return zf;
}
public System.Collections.Generic.IEnumerator<ZipEntry> GetEnumerator()
{
foreach (ZipEntry e in _entries)
yield return e;
}
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
public void ExtractAll(string path)
{
ExtractAll(path, false);
}
public void ExtractAll(string path, bool WantVerbose)
{
bool header = WantVerbose;
foreach (ZipEntry e in _entries)
{
if (header)
{
System.Console.WriteLine("\n{1,-22} {2,-6} {3,4} {4,-8} {0}",
"Name", "Modified", "Size", "Ratio", "Packed");
System.Console.WriteLine(new System.String('-', 72));
header = false;
}
if (WantVerbose)
System.Console.WriteLine("{1,-22} {2,-6} {3,4:F0}% {4,-8} {0}",
e.FileName,
e.LastModified.ToString("yyyy-MM-dd HH:mm:ss"),
e.UncompressedSize,
e.CompressionRatio,
e.CompressedSize);
e.Extract(path);
}
}
public void Extract(string filename)
{
this[filename].Extract();
}
public void Extract(string filename, System.IO.Stream s)
{
this[filename].Extract(s);
}
public ZipEntry this[String filename]
{
get
{
foreach (ZipEntry e in _entries)
{
if (e.FileName == filename) return e;
}
return null;
}
}
#endregion
// the destructor
~ZipFile()
{
// call Dispose with false. Since we're in the
// destructor call, the managed resources will be
// disposed of anyways.
Dispose(false);
}
public void Dispose()
{
// dispose of the managed and unmanaged resources
Dispose(true);
// tell the GC that the Finalize process no longer needs
// to be run for this object.
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposeManagedResources)
{
if (!this._disposed)
{
if (disposeManagedResources)
{
// dispose managed resources
if (_readstream != null)
{
_readstream.Dispose();
_readstream = null;
}
if (_writestream != null)
{
_writestream.Dispose();
_writestream = null;
}
}
this._disposed = true;
}
}
private System.IO.Stream _readstream;
private System.IO.FileStream _writestream;
private bool _Debug = false;
private bool _disposed = false;
private System.Collections.Generic.List<ZipEntry> _entries = null;
private System.Collections.Generic.List<ZipDirEntry> _direntries = null;
}
}
// Example usage:
// 1. Extracting all files from a Zip file:
//
// try
// {
// using(ZipFile zip= ZipFile.Read(ZipFile))
// {
// zip.ExtractAll(TargetDirectory, true);
// }
// }
// catch (System.Exception ex1)
// {
// System.Console.Error.WriteLine("exception: " + ex1);
// }
//
// 2. Extracting files from a zip individually:
//
// try
// {
// using(ZipFile zip= ZipFile.Read(ZipFile))
// {
// foreach (ZipEntry e in zip)
// {
// e.Extract(TargetDirectory);
// }
// }
// }
// catch (System.Exception ex1)
// {
// System.Console.Error.WriteLine("exception: " + ex1);
// }
//
// 3. Creating a zip archive:
//
// try
// {
// using(ZipFile zip= new ZipFile(NewZipFile))
// {
//
// String[] filenames= System.IO.Directory.GetFiles(Directory);
// foreach (String filename in filenames)
// {
// zip.Add(filename);
// }
//
// zip.Save();
// }
//
// }
// catch (System.Exception ex1)
// {
// System.Console.Error.WriteLine("exception: " + ex1);
// }
//
//
// ==================================================================
//
//
//
// Information on the ZIP format:
//
// From
// http://www.pkware.com/business_and_developers/developer/popups/appnote.txt
//
// Overall .ZIP file format:
//
// [local file header 1]
// [file data 1]
// [data descriptor 1] ** sometimes
// .
// .
// .
// [local file header n]
// [file data n]
// [data descriptor n] ** sometimes
// [archive decryption header]
// [archive extra data record]
// [central directory]
// [zip64 end of central directory record]
// [zip64 end of central directory locator]
// [end of central directory record]
//
// Local File Header format:
// local file header signature 4 bytes (0x04034b50)
// version needed to extract 2 bytes
// general purpose bit flag 2 bytes
// compression method 2 bytes
// last mod file time 2 bytes
// last mod file date 2 bytes
// crc-32 4 bytes
// compressed size 4 bytes
// uncompressed size 4 bytes
// file name length 2 bytes
// extra field length 2 bytes
// file name varies
// extra field varies
//
//
// Data descriptor: (used only when bit 3 of the general purpose bitfield is set)
// local file header signature 4 bytes (0x08074b50)
// crc-32 4 bytes
// compressed size 4 bytes
// uncompressed size 4 bytes
//
//
// Central directory structure:
//
// [file header 1]
// .
// .
// .
// [file header n]
// [digital signature]
//
//
// File header: (This is ZipDirEntry in the code above)
// central file header signature 4 bytes (0x02014b50)
// version made by 2 bytes
// version needed to extract 2 bytes
// general purpose bit flag 2 bytes
// compression method 2 bytes
// last mod file time 2 bytes
// last mod file date 2 bytes
// crc-32 4 bytes
// compressed size 4 bytes
// uncompressed size 4 bytes
// file name length 2 bytes
// extra field length 2 bytes
// file comment length 2 bytes
// disk number start 2 bytes
// internal file attributes 2 bytes
// external file attributes 4 bytes
// relative offset of local header 4 bytes
// file name (variable size)
// extra field (variable size)
// file comment (variable size)
//
// End of central directory record:
//
// end of central dir signature 4 bytes (0x06054b50)
// number of this disk 2 bytes
// number of the disk with the
// start of the central directory 2 bytes
// total number of entries in the
// central directory on this disk 2 bytes
// total number of entries in
// the central directory 2 bytes
// size of the central directory 4 bytes
// offset of start of central
// directory with respect to
// the starting disk number 4 bytes
// .ZIP file comment length 2 bytes
// .ZIP file comment (variable size)
//
// date and time are packed values, as MSDOS did them
// time: bits 0-4 : second
// 5-10: minute
// 11-15: hour
// date bits 0-4 : day
// 5-8: month
// 9-15 year (since 1980)
//
// see http://www.vsft.com/hal/dostime.htm
Submit an article or tip