/// <summary>
/// Rewrite the directory within a zipfile.
/// </summary>
///
/// <remarks>
///
/// <para>
/// In cases of data error, the directory in a zip file can get out of
/// synch with the entries in the zip file. This method attempts to fix
/// the zip file if this has occurred.
/// </para>
///
/// <para> This can take a long time for large zip files. </para>
///
/// <para> This won't work if the zip file uses a non-standard
/// code page - neither IBM437 nor UTF-8. </para>
///
/// <para>
/// This method is not supported in the Reduced or Compact Framework
/// versions of DotNetZip.
/// </para>
///
/// <para>
/// Developers using COM can use the <see
/// cref="ComHelper.FixZipDirectory(String)">ComHelper.FixZipDirectory(String)</see>
/// method.
/// </para>
///
/// </remarks>
///
/// <param name="zipFileName">The filename to of the zip file to fix.</param>
///
/// <seealso cref="CheckZip(string)"/>
/// <seealso cref="CheckZip(string,bool,System.IO.TextWriter)"/>
public static void FixZipDirectory(string zipFileName)
{
using (var zip = new ZipFile())
{
zip.FullScan = true;
zip.Initialize(zipFileName);
zip.Save(zipFileName);
}
}
/// <summary>
/// Reads one entry from the zip directory structure in the zip file.
/// </summary>
///
/// <param name="zf">
/// The zipfile for which a directory entry will be read. From this param, the
/// method gets the ReadStream and the expected text encoding
/// (ProvisionalAlternateEncoding) which is used if the entry is not marked
/// UTF-8.
/// </param>
///
/// <param name="previouslySeen">
/// a list of previously seen entry names; used to prevent duplicates.
/// </param>
///
/// <returns>the entry read from the archive.</returns>
internal static ZipEntry ReadDirEntry(ZipFile zf,
Dictionary<String,Object> previouslySeen)
{
System.IO.Stream s = zf.ReadStream;
System.Text.Encoding expectedEncoding = (zf.AlternateEncodingUsage == ZipOption.Always)
? zf.AlternateEncoding
: ZipFile.DefaultEncoding;
int signature = Ionic.Zip.SharedUtilities.ReadSignature(s);
// return null if this is not a local file header signature
if (IsNotValidZipDirEntrySig(signature))
{
s.Seek(-4, System.IO.SeekOrigin.Current);
// workitem 10178
Ionic.Zip.SharedUtilities.Workaround_Ladybug318918(s);
// Getting "not a ZipDirEntry signature" here is not always wrong or an
// error. This can happen when walking through a zipfile. After the
// last ZipDirEntry, we expect to read an
// EndOfCentralDirectorySignature. When we get this is how we know
// we've reached the end of the central directory.
if (signature != ZipConstants.EndOfCentralDirectorySignature &&
signature != ZipConstants.Zip64EndOfCentralDirectoryRecordSignature &&
signature != ZipConstants.ZipEntrySignature // workitem 8299
)
{
throw new BadReadException(String.Format(" Bad signature (0x{0:X8}) at position 0x{1:X8}", signature, s.Position));
}
return null;
}
int bytesRead = 42 + 4;
byte[] block = new byte[42];
int n = s.Read(block, 0, block.Length);
if (n != block.Length) return null;
int i = 0;
ZipEntry zde = new ZipEntry();
zde.AlternateEncoding = expectedEncoding;
zde._Source = ZipEntrySource.ZipFile;
zde._container = new ZipContainer(zf);
unchecked
{
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 = (Int16)(block[i++] + block[i++] * 256);
zde._TimeBlob = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
zde._LastModified = Ionic.Zip.SharedUtilities.PackedToDateTime(zde._TimeBlob);
zde._timestamp |= ZipEntryTimestamp.DOS;
zde._Crc32 = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
zde._CompressedSize = (uint)(block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256);
zde._UncompressedSize = (uint)(block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256);
}
// preserve
zde._CompressionMethod_FromZipFile = zde._CompressionMethod;
zde._filenameLength = (short)(block[i++] + block[i++] * 256);
zde._extraFieldLength = (short)(block[i++] + block[i++] * 256);
zde._commentLength = (short)(block[i++] + block[i++] * 256);
zde._diskNumber = (UInt32)(block[i++] + block[i++] * 256);
zde._InternalFileAttrs = (short)(block[i++] + block[i++] * 256);
zde._ExternalFileAttrs = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256;
zde._RelativeOffsetOfLocalHeader = (uint)(block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256);
// workitem 7801
zde.IsText = ((zde._InternalFileAttrs & 0x01) == 0x01);
block = new byte[zde._filenameLength];
n = s.Read(block, 0, block.Length);
bytesRead += n;
if ((zde._BitField & 0x0800) == 0x0800)
{
// UTF-8 is in use
zde._FileNameInArchive = Ionic.Zip.SharedUtilities.Utf8StringFromBuffer(block);
}
else
{
zde._FileNameInArchive = Ionic.Zip.SharedUtilities.StringFromBuffer(block, expectedEncoding);
}
// workitem 10330
// insure unique entry names
while (previouslySeen.ContainsKey(zde._FileNameInArchive))
{
zde._FileNameInArchive = CopyHelper.AppendCopyToFileName(zde._FileNameInArchive);
zde._metadataChanged = true;
}
if (zde.AttributesIndicateDirectory)
zde.MarkAsDirectory(); // may append a slash to filename if nec.
// workitem 6898
else if (zde._FileNameInArchive.EndsWith("/")) zde.MarkAsDirectory();
zde._CompressedFileDataSize = zde._CompressedSize;
if ((zde._BitField & 0x01) == 0x01)
{
// this may change after processing the Extra field
zde._Encryption_FromZipFile = zde._Encryption =
EncryptionAlgorithm.PkzipWeak;
zde._sourceIsEncrypted = true;
}
if (zde._extraFieldLength > 0)
{
zde._InputUsesZip64 = (zde._CompressedSize == 0xFFFFFFFF ||
zde._UncompressedSize == 0xFFFFFFFF ||
zde._RelativeOffsetOfLocalHeader == 0xFFFFFFFF);
// Console.WriteLine(" Input uses Z64?: {0}", zde._InputUsesZip64);
bytesRead += zde.ProcessExtraField(s, zde._extraFieldLength);
zde._CompressedFileDataSize = zde._CompressedSize;
}
// we've processed the extra field, so we know the encryption method is set now.
if (zde._Encryption == EncryptionAlgorithm.PkzipWeak)
{
// the "encryption header" of 12 bytes precedes the file data
zde._CompressedFileDataSize -= 12;
}
#if AESCRYPTO
else if (zde.Encryption == EncryptionAlgorithm.WinZipAes128 ||
zde.Encryption == EncryptionAlgorithm.WinZipAes256)
{
zde._CompressedFileDataSize = zde.CompressedSize -
(ZipEntry.GetLengthOfCryptoHeaderBytes(zde.Encryption) + 10);
zde._LengthOfTrailer = 10;
}
#endif
// tally the trailing descriptor
if ((zde._BitField & 0x0008) == 0x0008)
{
// sig, CRC, Comp and Uncomp sizes
if (zde._InputUsesZip64)
zde._LengthOfTrailer += 24;
else
zde._LengthOfTrailer += 16;
}
// workitem 12744
zde.AlternateEncoding = ((zde._BitField & 0x0800) == 0x0800)
? System.Text.Encoding.UTF8
:expectedEncoding;
zde.AlternateEncodingUsage = ZipOption.Always;
if (zde._commentLength > 0)
{
block = new byte[zde._commentLength];
n = s.Read(block, 0, block.Length);
bytesRead += n;
if ((zde._BitField & 0x0800) == 0x0800)
{
// UTF-8 is in use
zde._Comment = Ionic.Zip.SharedUtilities.Utf8StringFromBuffer(block);
}
else
{
zde._Comment = Ionic.Zip.SharedUtilities.StringFromBuffer(block, expectedEncoding);
}
}
//zde._LengthOfDirEntry = bytesRead;
return zde;
}
/// <summary>
/// Retrieve the ZipEntry items in the ZipFile that conform to the specified criteria.
/// </summary>
/// <remarks>
///
/// <para>
/// This method applies the criteria set in the FileSelector instance (as described in
/// the <see cref="FileSelector.SelectionCriteria"/>) to the specified ZipFile. Using this
/// method, for example, you can retrieve all entries from the given ZipFile that
/// have filenames ending in .txt.
/// </para>
///
/// <para>
/// Normally, applications would not call this method directly. This method is used
/// by the ZipFile class.
/// </para>
///
/// <para>
/// This overload allows the selection of ZipEntry instances from the ZipFile to be restricted
/// to entries contained within a particular directory in the ZipFile.
/// </para>
///
/// <para>
/// Using the appropriate SelectionCriteria, you can retrieve entries based on size,
/// time, and attributes. See <see cref="FileSelector.SelectionCriteria"/> for a
/// description of the syntax of the SelectionCriteria string.
/// </para>
///
/// </remarks>
///
/// <param name="zip">The ZipFile from which to retrieve entries.</param>
///
/// <param name="directoryPathInArchive">
/// the directory in the archive from which to select entries. If null, then
/// all directories in the archive are used.
/// </param>
///
/// <returns>a collection of ZipEntry objects that conform to the criteria.</returns>
public ICollection<ZipEntry> SelectEntries(ZipFile zip, string directoryPathInArchive)
{
if (zip == null)
throw new ArgumentNullException("zip");
var list = new List<ZipEntry>();
// workitem 8559
string slashSwapped = (directoryPathInArchive == null) ? null : directoryPathInArchive.Replace("/", "\\");
// workitem 9174
if (slashSwapped != null)
{
while (slashSwapped.EndsWith("\\"))
slashSwapped = slashSwapped.Substring(0, slashSwapped.Length - 1);
}
foreach (ZipEntry e in zip)
{
if (directoryPathInArchive == null || (Path.GetDirectoryName(e.FileName) == directoryPathInArchive)
|| (Path.GetDirectoryName(e.FileName) == slashSwapped)) // workitem 8559
if (this.Evaluate(e))
list.Add(e);
}
return list;
}
/// <summary>
/// Checks a zip file to see if its directory is consistent,
/// and optionally fixes the directory if necessary.
/// </summary>
///
/// <remarks>
///
/// <para>
/// In cases of data error, the directory within a zip file can get out of
/// synch with the entries in the zip file. This method checks the given
/// zip file, and returns true if this has occurred. It also optionally
/// fixes the zipfile, saving the fixed copy in <em>Name</em>_Fixed.zip.
/// </para>
///
/// <para>
/// This method may take a long time to run for large zip files. It
/// will take even longer if the file actually needs to be fixed, and if
/// <c>fixIfNecessary</c> is true.
/// </para>
///
/// <para>
/// This method is not supported in the Reduced or Compact
/// Framework versions of DotNetZip.
/// </para>
///
/// </remarks>
///
/// <param name="zipFileName">The filename to of the zip file to check.</param>
///
/// <param name="fixIfNecessary">If true, the method will fix the zip file if
/// necessary.</param>
///
/// <param name="writer">
/// a TextWriter in which messages generated while checking will be written.
/// </param>
///
/// <returns>true if the named zip is OK; false if the file needs to be fixed.</returns>
///
/// <seealso cref="CheckZip(string)"/>
/// <seealso cref="FixZipDirectory(string)"/>
public static bool CheckZip(string zipFileName, bool fixIfNecessary,
TextWriter writer)
{
ZipFile zip1 = null, zip2 = null;
bool isOk = true;
try
{
zip1 = new ZipFile();
zip1.FullScan = true;
zip1.Initialize(zipFileName);
zip2 = ZipFile.Read(zipFileName);
foreach (var e1 in zip1)
{
foreach (var e2 in zip2)
{
if (e1.FileName == e2.FileName)
{
if (e1._RelativeOffsetOfLocalHeader != e2._RelativeOffsetOfLocalHeader)
{
isOk = false;
if (writer != null)
writer.WriteLine("{0}: mismatch in RelativeOffsetOfLocalHeader (0x{1:X16} != 0x{2:X16})",
e1.FileName, e1._RelativeOffsetOfLocalHeader,
e2._RelativeOffsetOfLocalHeader);
}
if (e1._CompressedSize != e2._CompressedSize)
{
isOk = false;
if (writer != null)
writer.WriteLine("{0}: mismatch in CompressedSize (0x{1:X16} != 0x{2:X16})",
e1.FileName, e1._CompressedSize,
e2._CompressedSize);
}
if (e1._UncompressedSize != e2._UncompressedSize)
{
isOk = false;
if (writer != null)
writer.WriteLine("{0}: mismatch in UncompressedSize (0x{1:X16} != 0x{2:X16})",
e1.FileName, e1._UncompressedSize,
e2._UncompressedSize);
}
if (e1.CompressionMethod != e2.CompressionMethod)
{
isOk = false;
if (writer != null)
writer.WriteLine("{0}: mismatch in CompressionMethod (0x{1:X4} != 0x{2:X4})",
e1.FileName, e1.CompressionMethod,
e2.CompressionMethod);
}
if (e1.Crc != e2.Crc)
{
isOk = false;
if (writer != null)
writer.WriteLine("{0}: mismatch in Crc32 (0x{1:X4} != 0x{2:X4})",
e1.FileName, e1.Crc,
e2.Crc);
}
// found a match, so stop the inside loop
break;
}
}
}
zip2.Dispose();
zip2 = null;
if (!isOk && fixIfNecessary)
{
string newFileName = Path.GetFileNameWithoutExtension(zipFileName);
newFileName = System.String.Format("{0}_fixed.zip", newFileName);
zip1.Save(newFileName);
}
}
finally
{
if (zip1 != null) zip1.Dispose();
if (zip2 != null) zip2.Dispose();
}
return isOk;
}
private static void ReadZipFileComment(ZipFile zf)
{
// read the comment here
byte[] block = new byte[2];
zf.ReadStream.Read(block, 0, block.Length);
Int16 commentLength = (short)(block[0] + block[1] * 256);
if (commentLength > 0)
{
block = new byte[commentLength];
zf.ReadStream.Read(block, 0, block.Length);
// workitem 10392 - prefer ProvisionalAlternateEncoding,
// first. The fix for workitem 6513 tried to use UTF8
// only as necessary, but that is impossible to test
// for, in this direction. There's no way to know what
// characters the already-encoded bytes refer
// to. Therefore, must do what the user tells us.
string s1 = zf.AlternateEncoding.GetString(block, 0, block.Length);
zf.Comment = s1;
}
}
/// <summary>
/// Retrieve the ZipEntry items in the ZipFile that conform to the specified criteria.
/// </summary>
/// <remarks>
///
/// <para>
/// This method applies the criteria set in the FileSelector instance (as described in
/// the <see cref="FileSelector.SelectionCriteria"/>) to the specified ZipFile. Using this
/// method, for example, you can retrieve all entries from the given ZipFile that
/// have filenames ending in .txt.
/// </para>
///
/// <para>
/// Normally, applications would not call this method directly. This method is used
/// by the ZipFile class.
/// </para>
///
/// <para>
/// Using the appropriate SelectionCriteria, you can retrieve entries based on size,
/// time, and attributes. See <see cref="FileSelector.SelectionCriteria"/> for a
/// description of the syntax of the SelectionCriteria string.
/// </para>
///
/// </remarks>
///
/// <param name="zip">The ZipFile from which to retrieve entries.</param>
///
/// <returns>a collection of ZipEntry objects that conform to the criteria.</returns>
public ICollection<ZipEntry> SelectEntries(ZipFile zip)
{
if (zip == null)
throw new ArgumentNullException("zip");
var list = new List<ZipEntry>();
foreach (ZipEntry e in zip)
{
if (this.Evaluate(e))
list.Add(e);
}
return list;
}
// build the TOC by reading each entry in the file.
private static void ReadIntoInstance_Orig(ZipFile zf)
{
zf.OnReadStarted();
//zf._entries = new System.Collections.Generic.List<ZipEntry>();
zf._entries = new System.Collections.Generic.Dictionary<String,ZipEntry>();
ZipEntry e;
if (zf.Verbose)
if (zf.Name == null)
zf.StatusMessageTextWriter.WriteLine("Reading zip from stream...");
else
zf.StatusMessageTextWriter.WriteLine("Reading zip {0}...", zf.Name);
// work item 6647: PK00 (packed to removable disk)
bool firstEntry = true;
ZipContainer zc = new ZipContainer(zf);
while ((e = ZipEntry.ReadEntry(zc, firstEntry)) != null)
{
if (zf.Verbose)
zf.StatusMessageTextWriter.WriteLine(" {0}", e.FileName);
zf._entries.Add(e.FileName,e);
firstEntry = false;
}
// read the zipfile's central directory structure here.
// workitem 9912
// But, because it may be corrupted, ignore errors.
try
{
ZipEntry de;
// in lieu of hashset, use a dictionary
var previouslySeen = new Dictionary<String,Object>();
while ((de = ZipEntry.ReadDirEntry(zf, previouslySeen)) != null)
{
// Housekeeping: Since ZipFile exposes ZipEntry elements in the enumerator,
// we need to copy the comment that we grab from the ZipDirEntry
// into the ZipEntry, so the application can access the comment.
// Also since ZipEntry is used to Write zip files, we need to copy the
// file attributes to the ZipEntry as appropriate.
ZipEntry e1 = zf._entries[de.FileName];
if (e1 != null)
{
e1._Comment = de.Comment;
if (de.IsDirectory) e1.MarkAsDirectory();
}
previouslySeen.Add(de.FileName,null); // to prevent dupes
}
// workitem 8299
if (zf._locEndOfCDS > 0)
zf.ReadStream.Seek(zf._locEndOfCDS, SeekOrigin.Begin);
ReadCentralDirectoryFooter(zf);
if (zf.Verbose && !String.IsNullOrEmpty(zf.Comment))
zf.StatusMessageTextWriter.WriteLine("Zip file Comment: {0}", zf.Comment);
}
catch (ZipException) { }
catch (IOException) { }
zf.OnReadCompleted();
}
private static void ReadCentralDirectoryFooter(ZipFile zf)
{
Stream s = zf.ReadStream;
int signature = Ionic.Zip.SharedUtilities.ReadSignature(s);
byte[] block = null;
int j = 0;
if (signature == ZipConstants.Zip64EndOfCentralDirectoryRecordSignature)
{
// We have a ZIP64 EOCD
// This data block is 4 bytes sig, 8 bytes size, 44 bytes fixed data,
// followed by a variable-sized extension block. We have read the sig already.
// 8 - datasize (64 bits)
// 2 - version made by
// 2 - version needed to extract
// 4 - number of this disk
// 4 - number of the disk with the start of the CD
// 8 - total number of entries in the CD on this disk
// 8 - total number of entries in the CD
// 8 - size of the CD
// 8 - offset of the CD
// -----------------------
// 52 bytes
block = new byte[8 + 44];
s.Read(block, 0, block.Length);
Int64 DataSize = BitConverter.ToInt64(block, 0); // == 44 + the variable length
if (DataSize < 44)
throw new ZipException("Bad size in the ZIP64 Central Directory.");
zf._versionMadeBy = BitConverter.ToUInt16(block, j);
j += 2;
zf._versionNeededToExtract = BitConverter.ToUInt16(block, j);
j += 2;
zf._diskNumberWithCd = BitConverter.ToUInt32(block, j);
j += 2;
//zf._diskNumberWithCd++; // hack!!
// read the extended block
block = new byte[DataSize - 44];
s.Read(block, 0, block.Length);
// discard the result
signature = Ionic.Zip.SharedUtilities.ReadSignature(s);
if (signature != ZipConstants.Zip64EndOfCentralDirectoryLocatorSignature)
throw new ZipException("Inconsistent metadata in the ZIP64 Central Directory.");
block = new byte[16];
s.Read(block, 0, block.Length);
// discard the result
signature = Ionic.Zip.SharedUtilities.ReadSignature(s);
}
// Throw if this is not a signature for "end of central directory record"
// This is a sanity check.
if (signature != ZipConstants.EndOfCentralDirectorySignature)
{
s.Seek(-4, SeekOrigin.Current);
throw new BadReadException(String.Format("Bad signature ({0:X8}) at position 0x{1:X8}",
signature, s.Position));
}
// read the End-of-Central-Directory-Record
block = new byte[16];
zf.ReadStream.Read(block, 0, block.Length);
// off sz data
// -------------------------------------------------------
// 0 4 end of central dir signature (0x06054b50)
// 4 2 number of this disk
// 6 2 number of the disk with start of the central directory
// 8 2 total number of entries in the central directory on this disk
// 10 2 total number of entries in the central directory
// 12 4 size of the central directory
// 16 4 offset of start of central directory with respect to the starting disk number
// 20 2 ZIP file comment length
// 22 ?? ZIP file comment
if (zf._diskNumberWithCd == 0)
{
zf._diskNumberWithCd = BitConverter.ToUInt16(block, 2);
//zf._diskNumberWithCd++; // hack!!
}
// read the comment here
ReadZipFileComment(zf);
}
private static void ReadCentralDirectory(ZipFile zf)
{
// We must have the central directory footer record, in order to properly
// read zip dir entries from the central directory. This because the logic
// knows when to open a spanned file when the volume number for the central
// directory differs from the volume number for the zip entry. The
// _diskNumberWithCd was set when originally finding the offset for the
// start of the Central Directory.
// workitem 9214
bool inputUsesZip64 = false;
ZipEntry de;
// in lieu of hashset, use a dictionary
var previouslySeen = new Dictionary<String,object>();
while ((de = ZipEntry.ReadDirEntry(zf, previouslySeen)) != null)
{
de.ResetDirEntry();
zf.OnReadEntry(true, null);
if (zf.Verbose)
zf.StatusMessageTextWriter.WriteLine("entry {0}", de.FileName);
zf._entries.Add(de.FileName,de);
// workitem 9214
if (de._InputUsesZip64) inputUsesZip64 = true;
previouslySeen.Add(de.FileName, null); // to prevent dupes
}
// workitem 9214; auto-set the zip64 flag
if (inputUsesZip64) zf.UseZip64WhenSaving = Zip64Option.Always;
// workitem 8299
if (zf._locEndOfCDS > 0)
zf.ReadStream.Seek(zf._locEndOfCDS, SeekOrigin.Begin);
ReadCentralDirectoryFooter(zf);
if (zf.Verbose && !String.IsNullOrEmpty(zf.Comment))
zf.StatusMessageTextWriter.WriteLine("Zip file Comment: {0}", zf.Comment);
// We keep the read stream open after reading.
if (zf.Verbose)
zf.StatusMessageTextWriter.WriteLine("read in {0} entries.", zf._entries.Count);
zf.OnReadCompleted();
}
private static void Zip64SeekToCentralDirectory(ZipFile zf)
{
Stream s = zf.ReadStream;
byte[] block = new byte[16];
// seek back to find the ZIP64 EoCD.
// I think this might not work for .NET CF ?
s.Seek(-40, SeekOrigin.Current);
s.Read(block, 0, 16);
Int64 offset64 = BitConverter.ToInt64(block, 8);
zf._OffsetOfCentralDirectory = 0xFFFFFFFF;
zf._OffsetOfCentralDirectory64 = offset64;
// change for workitem 8098
s.Seek(offset64, SeekOrigin.Begin);
//zf.SeekFromOrigin(Offset64);
uint datum = (uint)Ionic.Zip.SharedUtilities.ReadInt(s);
if (datum != ZipConstants.Zip64EndOfCentralDirectoryRecordSignature)
throw new BadReadException(String.Format(" Bad signature (0x{0:X8}) looking for ZIP64 EoCD Record at position 0x{1:X8}", datum, s.Position));
s.Read(block, 0, 8);
Int64 Size = BitConverter.ToInt64(block, 0);
block = new byte[Size];
s.Read(block, 0, block.Length);
offset64 = BitConverter.ToInt64(block, 36);
// change for workitem 8098
s.Seek(offset64, SeekOrigin.Begin);
//zf.SeekFromOrigin(Offset64);
}
private static void ReadIntoInstance(ZipFile zf)
{
Stream s = zf.ReadStream;
try
{
zf._readName = zf._name; // workitem 13915
if (!s.CanSeek)
{
ReadIntoInstance_Orig(zf);
return;
}
zf.OnReadStarted();
// change for workitem 8098
//zf._originPosition = s.Position;
// Try reading the central directory, rather than scanning the file.
uint datum = ReadFirstFourBytes(s);
if (datum == ZipConstants.EndOfCentralDirectorySignature)
return;
// start at the end of the file...
// seek backwards a bit, then look for the EoCD signature.
int nTries = 0;
bool success = false;
// The size of the end-of-central-directory-footer plus 2 bytes is 18.
// This implies an archive comment length of 0. We'll add a margin of
// safety and start "in front" of that, when looking for the
// EndOfCentralDirectorySignature
long posn = s.Length - 64;
long maxSeekback = Math.Max(s.Length - 0x4000, 10);
do
{
if (posn < 0) posn = 0; // BOF
s.Seek(posn, SeekOrigin.Begin);
long bytesRead = SharedUtilities.FindSignature(s, (int)ZipConstants.EndOfCentralDirectorySignature);
if (bytesRead != -1)
success = true;
else
{
if (posn==0) break; // started at the BOF and found nothing
nTries++;
// Weird: with NETCF, negative offsets from SeekOrigin.End DO
// NOT WORK. So rather than seek a negative offset, we seek
// from SeekOrigin.Begin using a smaller number.
posn -= (32 * (nTries + 1) * nTries);
}
}
while (!success && posn > maxSeekback);
if (success)
{
// workitem 8299
zf._locEndOfCDS = s.Position - 4;
byte[] block = new byte[16];
s.Read(block, 0, block.Length);
zf._diskNumberWithCd = BitConverter.ToUInt16(block, 2);
if (zf._diskNumberWithCd == 0xFFFF)
throw new ZipException("Spanned archives with more than 65534 segments are not supported at this time.");
zf._diskNumberWithCd++; // I think the number in the file differs from reality by 1
int i = 12;
uint offset32 = (uint) BitConverter.ToUInt32(block, i);
if (offset32 == 0xFFFFFFFF)
{
Zip64SeekToCentralDirectory(zf);
}
else
{
zf._OffsetOfCentralDirectory = offset32;
// change for workitem 8098
s.Seek(offset32, SeekOrigin.Begin);
}
ReadCentralDirectory(zf);
}
else
{
// Could not find the central directory.
// Fallback to the old method.
// workitem 8098: ok
//s.Seek(zf._originPosition, SeekOrigin.Begin);
s.Seek(0L, SeekOrigin.Begin);
ReadIntoInstance_Orig(zf);
}
}
catch (Exception ex1)
{
if (zf._ReadStreamIsOurs && zf._readstream != null)
{
try
{
#if NETCF
zf._readstream.Close();
#else
zf._readstream.Dispose();
#endif
zf._readstream = null;
}
finally { }
}
throw new ZipException("Cannot read that as a ZipFile", ex1);
}
// the instance has been read in
zf._contentsChanged = false;
}
/// <summary>
/// Reads a zip archive from a stream, using the specified text Encoding, the
/// specified TextWriter for status messages,
/// and the specified ReadProgress event handler.
/// </summary>
///
/// <remarks>
/// <para>
/// Reading of zip content begins at the current position in the stream. This
/// means if you have a stream that concatenates regular data and zip data, if
/// you position the open, readable stream at the start of the zip data, you
/// will be able to read the zip archive using this constructor, or any of the
/// ZipFile constructors that accept a <see cref="System.IO.Stream" /> as
/// input. Some examples of where this might be useful: the zip content is
/// concatenated at the end of a regular EXE file, as some self-extracting
/// archives do. (Note: SFX files produced by DotNetZip do not work this
/// way). Another example might be a stream being read from a database, where
/// the zip content is embedded within an aggregate stream of data.
/// </para>
/// </remarks>
///
/// <param name="zipStream">the stream containing the zip data.</param>
///
/// <param name="statusMessageWriter">
/// The <c>System.IO.TextWriter</c> to which verbose status messages are written
/// during operations on the <c>ZipFile</c>. For example, in a console
/// application, System.Console.Out works, and will get a message for each entry
/// added to the ZipFile. If the TextWriter is <c>null</c>, no verbose messages
/// are written.
/// </param>
///
/// <param name="encoding">
/// The text encoding to use when reading entries that do not have the UTF-8
/// encoding bit set. Be careful specifying the encoding. If the value you use
/// here is not the same as the Encoding used when the zip archive was created
/// (possibly by a different archiver) you will get unexpected results and
/// possibly exceptions. See the <see cref="ProvisionalAlternateEncoding"/>
/// property for more information.
/// </param>
///
/// <param name="readProgress">
/// An event handler for Read operations.
/// </param>
///
/// <returns>an instance of ZipFile</returns>
private static ZipFile Read(Stream zipStream,
TextWriter statusMessageWriter,
System.Text.Encoding encoding,
EventHandler<ReadProgressEventArgs> readProgress)
{
if (zipStream == null)
throw new ArgumentNullException("zipStream");
ZipFile zf = new ZipFile();
zf._StatusMessageTextWriter = statusMessageWriter;
zf._alternateEncoding = encoding ?? ZipFile.DefaultEncoding;
zf._alternateEncodingUsage = ZipOption.Always;
if (readProgress != null)
zf.ReadProgress += readProgress;
zf._readstream = (zipStream.Position == 0L)
? zipStream
: new OffsetStream(zipStream);
zf._ReadStreamIsOurs = false;
if (zf.Verbose) zf._StatusMessageTextWriter.WriteLine("reading from stream...");
ReadIntoInstance(zf);
return zf;
}
/// <summary>
/// Reads a zip file archive using the specified text encoding, the specified
/// TextWriter for status messages, and the specified ReadProgress event handler,
/// and returns the instance.
/// </summary>
///
/// <param name="fileName">
/// The name of the zip archive to open.
/// This can be a fully-qualified or relative pathname.
/// </param>
///
/// <param name="readProgress">
/// An event handler for Read operations.
/// </param>
///
/// <param name="statusMessageWriter">
/// The <c>System.IO.TextWriter</c> to use for writing verbose status messages
/// during operations on the zip archive. A console application may wish to
/// pass <c>System.Console.Out</c> to get messages on the Console. A graphical
/// or headless application may wish to capture the messages in a different
/// <c>TextWriter</c>, such as a <c>System.IO.StringWriter</c>.
/// </param>
///
/// <param name="encoding">
/// The <c>System.Text.Encoding</c> to use when reading in the zip archive. Be
/// careful specifying the encoding. If the value you use here is not the same
/// as the Encoding used when the zip archive was created (possibly by a
/// different archiver) you will get unexpected results and possibly exceptions.
/// </param>
///
/// <returns>The instance read from the zip archive.</returns>
///
private static ZipFile Read(string fileName,
TextWriter statusMessageWriter,
System.Text.Encoding encoding,
EventHandler<ReadProgressEventArgs> readProgress)
{
ZipFile zf = new ZipFile();
zf.AlternateEncoding = encoding ?? DefaultEncoding;
zf.AlternateEncodingUsage = ZipOption.Always;
zf._StatusMessageTextWriter = statusMessageWriter;
zf._name = fileName;
if (readProgress != null)
zf.ReadProgress = readProgress;
if (zf.Verbose) zf._StatusMessageTextWriter.WriteLine("reading from {0}...", fileName);
ReadIntoInstance(zf);
zf._fileAlreadyExists = true;
return zf;
}
