old_flsystem/类库/OnlineRepair/ZIP/Zip/ZipInputStream.cs

676 lines
20 KiB
C#

// ZipInputStream.cs
//
// Copyright (C) 2001 Mike Krueger
// Copyright (C) 2004 John Reilly
//
// This file was translated from java, it was part of the GNU Classpath
// Copyright (C) 2001 Free Software Foundation, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library. Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
//
// As a special exception, the copyright holders of this library give you
// permission to link this library with independent modules to produce an
// executable, regardless of the license terms of these independent
// modules, and to copy and distribute the resulting executable under
// terms of your choice, provided that you also meet, for each linked
// independent module, the terms and conditions of the license of that
// module. An independent module is a module which is not derived from
// or based on this library. If you modify this library, you may extend
// this exception to your version of the library, but you are not
// obligated to do so. If you do not wish to do so, delete this
// exception statement from your version.
// HISTORY
// 2010-05-25 Z-1663 Fixed exception when testing local header compressed size of -1
using System;
using System.IO;
using ICSharpCode.SharpZipLib.Checksums;
using ICSharpCode.SharpZipLib.Zip.Compression;
using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
#if !NETCF_1_0
using ICSharpCode.SharpZipLib.Encryption;
#endif
namespace ICSharpCode.SharpZipLib.Zip
{
/// <summary>
/// This is an InflaterInputStream that reads the files baseInputStream an zip archive
/// one after another. It has a special method to get the zip entry of
/// the next file. The zip entry contains information about the file name
/// size, compressed size, Crc, etc.
/// It includes support for Stored and Deflated entries.
/// <br/>
/// <br/>Author of the original java version : Jochen Hoenicke
/// </summary>
///
/// <example> This sample shows how to read a zip file
/// <code lang="C#">
/// using System;
/// using System.Text;
/// using System.IO;
///
/// using ICSharpCode.SharpZipLib.Zip;
///
/// class MainClass
/// {
/// public static void Main(string[] args)
/// {
/// using ( ZipInputStream s = new ZipInputStream(File.OpenRead(args[0]))) {
///
/// ZipEntry theEntry;
/// const int size = 2048;
/// byte[] data = new byte[2048];
///
/// while ((theEntry = s.GetNextEntry()) != null) {
/// if ( entry.IsFile ) {
/// Console.Write("Show contents (y/n) ?");
/// if (Console.ReadLine() == "y") {
/// while (true) {
/// size = s.Read(data, 0, data.Length);
/// if (size > 0) {
/// Console.Write(new ASCIIEncoding().GetString(data, 0, size));
/// } else {
/// break;
/// }
/// }
/// }
/// }
/// }
/// }
/// }
/// }
/// </code>
/// </example>
public class ZipInputStream : InflaterInputStream
{
#region Instance Fields
/// <summary>
/// Delegate for reading bytes from a stream.
/// </summary>
delegate int ReadDataHandler(byte[] b, int offset, int length);
/// <summary>
/// The current reader this instance.
/// </summary>
ReadDataHandler internalReader;
Crc32 crc = new Crc32();
ZipEntry entry;
long size;
int method;
int flags;
string password;
#endregion
#region Constructors
/// <summary>
/// Creates a new Zip input stream, for reading a zip archive.
/// </summary>
/// <param name="baseInputStream">The underlying <see cref="Stream"/> providing data.</param>
public ZipInputStream(Stream baseInputStream)
: base(baseInputStream, new Inflater(true))
{
internalReader = new ReadDataHandler(ReadingNotAvailable);
}
/// <summary>
/// Creates a new Zip input stream, for reading a zip archive.
/// </summary>
/// <param name="baseInputStream">The underlying <see cref="Stream"/> providing data.</param>
/// <param name="bufferSize">Size of the buffer.</param>
public ZipInputStream( Stream baseInputStream, int bufferSize )
: base(baseInputStream, new Inflater(true), bufferSize)
{
internalReader = new ReadDataHandler(ReadingNotAvailable);
}
#endregion
/// <summary>
/// Optional password used for encryption when non-null
/// </summary>
/// <value>A password for all encrypted <see cref="ZipEntry">entries </see> in this <see cref="ZipInputStream"/></value>
public string Password
{
get {
return password;
}
set {
password = value;
}
}
/// <summary>
/// Gets a value indicating if there is a current entry and it can be decompressed
/// </summary>
/// <remarks>
/// The entry can only be decompressed if the library supports the zip features required to extract it.
/// See the <see cref="ZipEntry.Version">ZipEntry Version</see> property for more details.
/// </remarks>
public bool CanDecompressEntry {
get {
return (entry != null) && entry.CanDecompress;
}
}
/// <summary>
/// Advances to the next entry in the archive
/// </summary>
/// <returns>
/// The next <see cref="ZipEntry">entry</see> in the archive or null if there are no more entries.
/// </returns>
/// <remarks>
/// If the previous entry is still open <see cref="CloseEntry">CloseEntry</see> is called.
/// </remarks>
/// <exception cref="InvalidOperationException">
/// Input stream is closed
/// </exception>
/// <exception cref="ZipException">
/// Password is not set, password is invalid, compression method is invalid,
/// version required to extract is not supported
/// </exception>
public ZipEntry GetNextEntry()
{
if (crc == null) {
throw new InvalidOperationException("Closed.");
}
if (entry != null) {
CloseEntry();
}
int header = inputBuffer.ReadLeInt();
if (header == ZipConstants.CentralHeaderSignature ||
header == ZipConstants.EndOfCentralDirectorySignature ||
header == ZipConstants.CentralHeaderDigitalSignature ||
header == ZipConstants.ArchiveExtraDataSignature ||
header == ZipConstants.Zip64CentralFileHeaderSignature) {
// No more individual entries exist
Close();
return null;
}
// -jr- 07-Dec-2003 Ignore spanning temporary signatures if found
// Spanning signature is same as descriptor signature and is untested as yet.
if ( (header == ZipConstants.SpanningTempSignature) || (header == ZipConstants.SpanningSignature) ) {
header = inputBuffer.ReadLeInt();
}
if (header != ZipConstants.LocalHeaderSignature) {
throw new ZipException("Wrong Local header signature: 0x" + String.Format("{0:X}", header));
}
short versionRequiredToExtract = (short)inputBuffer.ReadLeShort();
flags = inputBuffer.ReadLeShort();
method = inputBuffer.ReadLeShort();
uint dostime = (uint)inputBuffer.ReadLeInt();
int crc2 = inputBuffer.ReadLeInt();
csize = inputBuffer.ReadLeInt();
size = inputBuffer.ReadLeInt();
int nameLen = inputBuffer.ReadLeShort();
int extraLen = inputBuffer.ReadLeShort();
bool isCrypted = (flags & 1) == 1;
byte[] buffer = new byte[nameLen];
inputBuffer.ReadRawBuffer(buffer);
string name = ZipConstants.ConvertToStringExt(flags, buffer);
entry = new ZipEntry(name, versionRequiredToExtract);
entry.Flags = flags;
entry.CompressionMethod = (CompressionMethod)method;
if ((flags & 8) == 0) {
entry.Crc = crc2 & 0xFFFFFFFFL;
entry.Size = size & 0xFFFFFFFFL;
entry.CompressedSize = csize & 0xFFFFFFFFL;
entry.CryptoCheckValue = (byte)((crc2 >> 24) & 0xff);
} else {
// This allows for GNU, WinZip and possibly other archives, the PKZIP spec
// says these values are zero under these circumstances.
if (crc2 != 0) {
entry.Crc = crc2 & 0xFFFFFFFFL;
}
if (size != 0) {
entry.Size = size & 0xFFFFFFFFL;
}
if (csize != 0) {
entry.CompressedSize = csize & 0xFFFFFFFFL;
}
entry.CryptoCheckValue = (byte)((dostime >> 8) & 0xff);
}
entry.DosTime = dostime;
// If local header requires Zip64 is true then the extended header should contain
// both values.
// Handle extra data if present. This can set/alter some fields of the entry.
if (extraLen > 0) {
byte[] extra = new byte[extraLen];
inputBuffer.ReadRawBuffer(extra);
entry.ExtraData = extra;
}
entry.ProcessExtraData(true);
if ( entry.CompressedSize >= 0 ) {
csize = entry.CompressedSize;
}
if ( entry.Size >= 0 ) {
size = entry.Size;
}
if (method == (int)CompressionMethod.Stored && (!isCrypted && csize != size || (isCrypted && csize - ZipConstants.CryptoHeaderSize != size))) {
throw new ZipException("Stored, but compressed != uncompressed");
}
// Determine how to handle reading of data if this is attempted.
if (entry.IsCompressionMethodSupported()) {
internalReader = new ReadDataHandler(InitialRead);
} else {
internalReader = new ReadDataHandler(ReadingNotSupported);
}
return entry;
}
/// <summary>
/// Read data descriptor at the end of compressed data.
/// </summary>
void ReadDataDescriptor()
{
if (inputBuffer.ReadLeInt() != ZipConstants.DataDescriptorSignature) {
throw new ZipException("Data descriptor signature not found");
}
entry.Crc = inputBuffer.ReadLeInt() & 0xFFFFFFFFL;
if ( entry.LocalHeaderRequiresZip64 ) {
csize = inputBuffer.ReadLeLong();
size = inputBuffer.ReadLeLong();
} else {
csize = inputBuffer.ReadLeInt();
size = inputBuffer.ReadLeInt();
}
entry.CompressedSize = csize;
entry.Size = size;
}
/// <summary>
/// Complete cleanup as the final part of closing.
/// </summary>
/// <param name="testCrc">True if the crc value should be tested</param>
void CompleteCloseEntry(bool testCrc)
{
StopDecrypting();
if ((flags & 8) != 0) {
ReadDataDescriptor();
}
size = 0;
if ( testCrc &&
((crc.Value & 0xFFFFFFFFL) != entry.Crc) && (entry.Crc != -1)) {
throw new ZipException("CRC mismatch");
}
crc.Reset();
if (method == (int)CompressionMethod.Deflated) {
inf.Reset();
}
entry = null;
}
/// <summary>
/// Closes the current zip entry and moves to the next one.
/// </summary>
/// <exception cref="InvalidOperationException">
/// The stream is closed
/// </exception>
/// <exception cref="ZipException">
/// The Zip stream ends early
/// </exception>
public void CloseEntry()
{
if (crc == null) {
throw new InvalidOperationException("Closed");
}
if (entry == null) {
return;
}
if (method == (int)CompressionMethod.Deflated) {
if ((flags & 8) != 0) {
// We don't know how much we must skip, read until end.
byte[] tmp = new byte[4096];
// Read will close this entry
while (Read(tmp, 0, tmp.Length) > 0) {
}
return;
}
csize -= inf.TotalIn;
inputBuffer.Available += inf.RemainingInput;
}
if ( (inputBuffer.Available > csize) && (csize >= 0) ) {
inputBuffer.Available = (int)((long)inputBuffer.Available - csize);
} else {
csize -= inputBuffer.Available;
inputBuffer.Available = 0;
while (csize != 0) {
long skipped = base.Skip(csize);
if (skipped <= 0) {
throw new ZipException("Zip archive ends early.");
}
csize -= skipped;
}
}
CompleteCloseEntry(false);
}
/// <summary>
/// Returns 1 if there is an entry available
/// Otherwise returns 0.
/// </summary>
public override int Available {
get {
return entry != null ? 1 : 0;
}
}
/// <summary>
/// Returns the current size that can be read from the current entry if available
/// </summary>
/// <exception cref="ZipException">Thrown if the entry size is not known.</exception>
/// <exception cref="InvalidOperationException">Thrown if no entry is currently available.</exception>
public override long Length
{
get {
if ( entry != null ) {
if ( entry.Size >= 0 ) {
return entry.Size;
} else {
throw new ZipException("Length not available for the current entry");
}
}
else {
throw new InvalidOperationException("No current entry");
}
}
}
/// <summary>
/// Reads a byte from the current zip entry.
/// </summary>
/// <returns>
/// The byte or -1 if end of stream is reached.
/// </returns>
public override int ReadByte()
{
byte[] b = new byte[1];
if (Read(b, 0, 1) <= 0) {
return -1;
}
return b[0] & 0xff;
}
/// <summary>
/// Handle attempts to read by throwing an <see cref="InvalidOperationException"/>.
/// </summary>
/// <param name="destination">The destination array to store data in.</param>
/// <param name="offset">The offset at which data read should be stored.</param>
/// <param name="count">The maximum number of bytes to read.</param>
/// <returns>Returns the number of bytes actually read.</returns>
int ReadingNotAvailable(byte[] destination, int offset, int count)
{
throw new InvalidOperationException("Unable to read from this stream");
}
/// <summary>
/// Handle attempts to read from this entry by throwing an exception
/// </summary>
int ReadingNotSupported(byte[] destination, int offset, int count)
{
throw new ZipException("The compression method for this entry is not supported");
}
/// <summary>
/// Perform the initial read on an entry which may include
/// reading encryption headers and setting up inflation.
/// </summary>
/// <param name="destination">The destination to fill with data read.</param>
/// <param name="offset">The offset to start reading at.</param>
/// <param name="count">The maximum number of bytes to read.</param>
/// <returns>The actual number of bytes read.</returns>
int InitialRead(byte[] destination, int offset, int count)
{
if ( !CanDecompressEntry ) {
throw new ZipException("Library cannot extract this entry. Version required is (" + entry.Version.ToString() + ")");
}
// Handle encryption if required.
if (entry.IsCrypted) {
#if NETCF_1_0
throw new ZipException("Encryption not supported for Compact Framework 1.0");
#else
if (password == null) {
throw new ZipException("No password set.");
}
// Generate and set crypto transform...
PkzipClassicManaged managed = new PkzipClassicManaged();
byte[] key = PkzipClassic.GenerateKeys(ZipConstants.ConvertToArray(password));
inputBuffer.CryptoTransform = managed.CreateDecryptor(key, null);
byte[] cryptbuffer = new byte[ZipConstants.CryptoHeaderSize];
inputBuffer.ReadClearTextBuffer(cryptbuffer, 0, ZipConstants.CryptoHeaderSize);
if (cryptbuffer[ZipConstants.CryptoHeaderSize - 1] != entry.CryptoCheckValue) {
throw new ZipException("Invalid password");
}
if (csize >= ZipConstants.CryptoHeaderSize) {
csize -= ZipConstants.CryptoHeaderSize;
}
else if ( (entry.Flags & (int)GeneralBitFlags.Descriptor) == 0 ) {
throw new ZipException(string.Format("Entry compressed size {0} too small for encryption", csize));
}
#endif
} else {
#if !NETCF_1_0
inputBuffer.CryptoTransform = null;
#endif
}
if ((csize > 0) || ((flags & (int)GeneralBitFlags.Descriptor) != 0)) {
if ((method == (int)CompressionMethod.Deflated) && (inputBuffer.Available > 0)) {
inputBuffer.SetInflaterInput(inf);
}
internalReader = new ReadDataHandler(BodyRead);
return BodyRead(destination, offset, count);
}
else {
internalReader = new ReadDataHandler(ReadingNotAvailable);
return 0;
}
}
/// <summary>
/// Read a block of bytes from the stream.
/// </summary>
/// <param name="buffer">The destination for the bytes.</param>
/// <param name="offset">The index to start storing data.</param>
/// <param name="count">The number of bytes to attempt to read.</param>
/// <returns>Returns the number of bytes read.</returns>
/// <remarks>Zero bytes read means end of stream.</remarks>
public override int Read(byte[] buffer, int offset, int count)
{
if ( buffer == null ) {
throw new ArgumentNullException("buffer");
}
if ( offset < 0 ) {
#if NETCF_1_0
throw new ArgumentOutOfRangeException("offset");
#else
throw new ArgumentOutOfRangeException("offset", "Cannot be negative");
#endif
}
if ( count < 0 ) {
#if NETCF_1_0
throw new ArgumentOutOfRangeException("count");
#else
throw new ArgumentOutOfRangeException("count", "Cannot be negative");
#endif
}
if ( (buffer.Length - offset) < count ) {
throw new ArgumentException("Invalid offset/count combination");
}
return internalReader(buffer, offset, count);
}
/// <summary>
/// Reads a block of bytes from the current zip entry.
/// </summary>
/// <returns>
/// The number of bytes read (this may be less than the length requested, even before the end of stream), or 0 on end of stream.
/// </returns>
/// <exception name="IOException">
/// An i/o error occured.
/// </exception>
/// <exception cref="ZipException">
/// The deflated stream is corrupted.
/// </exception>
/// <exception cref="InvalidOperationException">
/// The stream is not open.
/// </exception>
int BodyRead(byte[] buffer, int offset, int count)
{
if ( crc == null ) {
throw new InvalidOperationException("Closed");
}
if ( (entry == null) || (count <= 0) ) {
return 0;
}
if ( offset + count > buffer.Length ) {
throw new ArgumentException("Offset + count exceeds buffer size");
}
bool finished = false;
switch (method) {
case (int)CompressionMethod.Deflated:
count = base.Read(buffer, offset, count);
if (count <= 0) {
if (!inf.IsFinished) {
throw new ZipException("Inflater not finished!");
}
inputBuffer.Available = inf.RemainingInput;
// A csize of -1 is from an unpatched local header
if ((flags & 8) == 0 &&
(inf.TotalIn != csize && csize != 0xFFFFFFFF && csize != -1 || inf.TotalOut != size)) {
throw new ZipException("Size mismatch: " + csize + ";" + size + " <-> " + inf.TotalIn + ";" + inf.TotalOut);
}
inf.Reset();
finished = true;
}
break;
case (int)CompressionMethod.Stored:
if ( (count > csize) && (csize >= 0) ) {
count = (int)csize;
}
if ( count > 0 ) {
count = inputBuffer.ReadClearTextBuffer(buffer, offset, count);
if (count > 0) {
csize -= count;
size -= count;
}
}
if (csize == 0) {
finished = true;
} else {
if (count < 0) {
throw new ZipException("EOF in stored block");
}
}
break;
}
if (count > 0) {
crc.Update(buffer, offset, count);
}
if (finished) {
CompleteCloseEntry(true);
}
return count;
}
/// <summary>
/// Closes the zip input stream
/// </summary>
public override void Close()
{
internalReader = new ReadDataHandler(ReadingNotAvailable);
crc = null;
entry = null;
base.Close();
}
}
}