/// <summary>
/// Read the next entry from the zip file.
/// </summary>
///
/// <remarks>
/// <para>
/// Call this method just before calling <see cref="Read(byte[], int, int)"/>,
/// to position the pointer in the zip file to the next entry that can be
/// read. Subsequent calls to <c>Read()</c>, will decrypt and decompress the
/// data in the zip file, until <c>Read()</c> returns 0.
/// </para>
///
/// <para>
/// Each time you call <c>GetNextEntry()</c>, the pointer in the wrapped
/// stream is moved to the next entry in the zip file. If you call <see
/// cref="Seek(long, SeekOrigin)"/>, and thus re-position the pointer within
/// the file, you will need to call <c>GetNextEntry()</c> again, to insure
/// that the file pointer is positioned at the beginning of a zip entry.
/// </para>
///
/// <para>
/// This method returns the <c>ZipEntry</c>. Using a stream approach, you will
/// read the raw bytes for an entry in a zip file via calls to <c>Read()</c>.
/// Alternatively, you can extract an entry into a file, or a stream, by
/// calling <see cref="ZipEntry.Extract()"/>, or one of its siblings.
/// </para>
///
/// </remarks>
///
/// <returns>
/// The <c>ZipEntry</c> read. Returns null (or Nothing in VB) if there are no more
/// entries in the zip file.
/// </returns>
///
public ZipEntry GetNextEntry()
{
if (_findRequired)
{
// find the next signature
long d = SharedUtilities.FindSignature(_inputStream, ZipConstants.ZipEntrySignature);
if (d == -1)
{
return(null);
}
// back up 4 bytes: ReadEntry assumes the file pointer is positioned before the entry signature
_inputStream.Seek(-4, SeekOrigin.Current);
// workitem 10178
Chama.Utils.Ionic.Zip.SharedUtilities.Workaround_Ladybug318918(_inputStream);
}
// workitem 10923
else if (_firstEntry)
{
// we've already read one entry.
// Seek to the end of it.
_inputStream.Seek(_endOfEntry, SeekOrigin.Begin);
Chama.Utils.Ionic.Zip.SharedUtilities.Workaround_Ladybug318918(_inputStream);
}
_currentEntry = ZipEntry.ReadEntry(_container, !_firstEntry);
// ReadEntry leaves the file position after all the entry
// data and the optional bit-3 data descriptpr. This is
// where the next entry would normally start.
_endOfEntry = _inputStream.Position;
_firstEntry = true;
_needSetup = true;
_findRequired = false;
return(_currentEntry);
}
/// <summary>
/// This initializes the cipher with the given password.
/// See AppNote.txt for details.
/// </summary>
///
/// <param name="passphrase">
/// The passphrase for encrypting or decrypting with this cipher.
/// </param>
///
/// <remarks>
/// <code>
/// Step 1 - Initializing the encryption keys
/// -----------------------------------------
/// Start with these keys:
/// Key(0) := 305419896 (0x12345678)
/// Key(1) := 591751049 (0x23456789)
/// Key(2) := 878082192 (0x34567890)
///
/// Then, initialize the keys with a password:
///
/// loop for i from 0 to length(password)-1
/// update_keys(password(i))
/// end loop
///
/// Where update_keys() is defined as:
///
/// update_keys(char):
/// Key(0) := crc32(key(0),char)
/// Key(1) := Key(1) + (Key(0) bitwiseAND 000000ffH)
/// Key(1) := Key(1) * 134775813 + 1
/// Key(2) := crc32(key(2),key(1) rightshift 24)
/// end update_keys
///
/// Where crc32(old_crc,char) is a routine that given a CRC value and a
/// character, returns an updated CRC value after applying the CRC-32
/// algorithm described elsewhere in this document.
///
/// </code>
///
/// <para>
/// After the keys are initialized, then you can use the cipher to
/// encrypt the plaintext.
/// </para>
///
/// <para>
/// Essentially we encrypt the password with the keys, then discard the
/// ciphertext for the password. This initializes the keys for later use.
/// </para>
///
/// </remarks>
public void InitCipher(string passphrase)
{
byte[] p = SharedUtilities.StringToByteArray(passphrase);
for (int i = 0; i < passphrase.Length; i++)
{
UpdateKeys(p[i]);
}
}
/// <summary>
/// Saves the Zip archive to a file, specified by the Name property of the
/// <c>ZipFile</c>.
/// </summary>
///
/// <remarks>
/// <para>
/// The <c>ZipFile</c> instance is written to storage, typically a zip file
/// in a filesystem, only when the caller calls <c>Save</c>. In the typical
/// case, the Save operation writes the zip content to a temporary file, and
/// then renames the temporary file to the desired name. If necessary, this
/// method will delete a pre-existing file before the rename.
/// </para>
///
/// <para>
/// The <see cref="ZipFile.Name"/> property is specified either explicitly,
/// or implicitly using one of the parameterized ZipFile constructors. For
/// COM Automation clients, the <c>Name</c> property must be set explicitly,
/// because COM Automation clients cannot call parameterized constructors.
/// </para>
///
/// <para>
/// When using a filesystem file for the Zip output, it is possible to call
/// <c>Save</c> multiple times on the <c>ZipFile</c> instance. With each
/// call the zip content is re-written to the same output file.
/// </para>
///
/// <para>
/// Data for entries that have been added to the <c>ZipFile</c> instance is
/// written to the output when the <c>Save</c> method is called. This means
/// that the input streams for those entries must be available at the time
/// the application calls <c>Save</c>. If, for example, the application
/// adds entries with <c>AddEntry</c> using a dynamically-allocated
/// <c>MemoryStream</c>, the memory stream must not have been disposed
/// before the call to <c>Save</c>. See the <see
/// cref="ZipEntry.InputStream"/> property for more discussion of the
/// availability requirements of the input stream for an entry, and an
/// approach for providing just-in-time stream lifecycle management.
/// </para>
///
/// </remarks>
///
/// <seealso cref="Chama.Utils.Ionic.Zip.ZipFile.AddEntry(String, System.IO.Stream)"/>
///
/// <exception cref="Chama.Utils.Ionic.Zip.BadStateException">
/// Thrown if you haven't specified a location or stream for saving the zip,
/// either in the constructor or by setting the Name property, or if you try
/// to save a regular zip archive to a filename with a .exe extension.
/// </exception>
///
/// <exception cref="System.OverflowException">
/// Thrown if <see cref="MaxOutputSegmentSize"/> is non-zero, and the number
/// of segments that would be generated for the spanned zip file during the
/// save operation exceeds 99. If this happens, you need to increase the
/// segment size.
/// </exception>
///
public void Save()
{
try
{
bool thisSaveUsedZip64 = false;
_saveOperationCanceled = false;
_numberOfSegmentsForMostRecentSave = 0;
OnSaveStarted();
if (WriteStream == null)
{
throw new BadStateException("You haven't specified where to save the zip.");
}
if (_name != null && _name.EndsWith(".exe") && !_SavingSfx)
{
throw new BadStateException("You specified an EXE for a plain zip file.");
}
// check if modified, before saving.
if (!_contentsChanged)
{
OnSaveCompleted();
if (Verbose)
{
StatusMessageTextWriter.WriteLine("No save is necessary....");
}
return;
}
Reset(true);
if (Verbose)
{
StatusMessageTextWriter.WriteLine("saving....");
}
// validate the number of entries
if (_entries.Count >= 0xFFFF && _zip64 == Zip64Option.Never)
{
throw new ZipException("The number of entries is 65535 or greater. Consider setting the UseZip64WhenSaving property on the ZipFile instance.");
}
// write an entry in the zip for each file
int n = 0;
// workitem 9831
ICollection <ZipEntry> c = (SortEntriesBeforeSaving) ? EntriesSorted : Entries;
foreach (ZipEntry e in c) // _entries.Values
{
OnSaveEntry(n, e, true);
e.Write(WriteStream);
if (_saveOperationCanceled)
{
break;
}
n++;
OnSaveEntry(n, e, false);
if (_saveOperationCanceled)
{
break;
}
// Some entries can be skipped during the save.
if (e.IncludedInMostRecentSave)
{
thisSaveUsedZip64 |= e.OutputUsedZip64.Value;
}
}
if (_saveOperationCanceled)
{
return;
}
var zss = WriteStream as ZipSegmentedStream;
_numberOfSegmentsForMostRecentSave = (zss != null)
? zss.CurrentSegment
: 1;
bool directoryNeededZip64 =
ZipOutput.WriteCentralDirectoryStructure
(WriteStream,
c,
_numberOfSegmentsForMostRecentSave,
_zip64,
Comment,
new ZipContainer(this));
OnSaveEvent(ZipProgressEventType.Saving_AfterSaveTempArchive);
_hasBeenSaved = true;
_contentsChanged = false;
thisSaveUsedZip64 |= directoryNeededZip64;
_OutputUsesZip64 = new Nullable <bool>(thisSaveUsedZip64);
// do the rename as necessary
if (_name != null &&
(_temporaryFileName != null || zss != null))
{
// _temporaryFileName may remain null if we are writing to a stream.
// only close the stream if there is a file behind it.
#if NETCF
WriteStream.Close();
#else
WriteStream.Dispose();
#endif
if (_saveOperationCanceled)
{
return;
}
if (_fileAlreadyExists && this._readstream != null)
{
// This means we opened and read a zip file.
// If we are now saving to the same file, we need to close the
// orig file, first.
this._readstream.Close();
this._readstream = null;
// the archiveStream for each entry needs to be null
foreach (var e in c)
{
var zss1 = e._archiveStream as ZipSegmentedStream;
if (zss1 != null)
#if NETCF
{ zss1.Close(); }
#else
{ zss1.Dispose(); }
#endif
e._archiveStream = null;
}
}
string tmpName = null;
if (File.Exists(_name))
{
// the steps:
//
// 1. Delete tmpName
// 2. move existing zip to tmpName
// 3. rename (File.Move) working file to name of existing zip
// 4. delete tmpName
//
// This series of steps avoids the exception,
// System.IO.IOException:
// "Cannot create a file when that file already exists."
//
// Cannot just call File.Replace() here because
// there is a possibility that the TEMP volume is different
// that the volume for the final file (c:\ vs d:\).
// So we need to do a Delete+Move pair.
//
// But, when doing the delete, Windows allows a process to
// delete the file, even though it is held open by, say, a
// virus scanner. It gets internally marked as "delete
// pending". The file does not actually get removed from the
// file system, it is still there after the File.Delete
// call.
//
// Therefore, we need to move the existing zip, which may be
// held open, to some other name. Then rename our working
// file to the desired name, then delete (possibly delete
// pending) the "other name".
//
// Ideally this would be transactional. It's possible that the
// delete succeeds and the move fails. Lacking transactions, if
// this kind of failure happens, we're hosed, and this logic will
// throw on the next File.Move().
//
//File.Delete(_name);
// workitem 10447
#if NETCF || SILVERLIGHT
tmpName = _name + "." + SharedUtilities.GenerateRandomStringImpl(8, 0) + ".tmp";
#else
tmpName = _name + "." + Path.GetRandomFileName();
#endif
if (File.Exists(tmpName))
{
DeleteFileWithRetry(tmpName);
}
File.Move(_name, tmpName);
}
OnSaveEvent(ZipProgressEventType.Saving_BeforeRenameTempArchive);
File.Move((zss != null) ? zss.CurrentTempName : _temporaryFileName,
_name);
OnSaveEvent(ZipProgressEventType.Saving_AfterRenameTempArchive);
if (tmpName != null)
{
try
{
// not critical
if (File.Exists(tmpName))
{
File.Delete(tmpName);
}
}
catch
{
// don't care about exceptions here.
}
}
_fileAlreadyExists = true;
}
NotifyEntriesSaveComplete(c);
OnSaveCompleted();
_JustSaved = true;
}
// workitem 5043
finally
{
CleanupAfterSaveOperation();
}
return;
}
public long TruncateBackward(uint diskNumber, long offset)
{
// Console.WriteLine("***ZSS.Trunc to disk {0}", diskNumber);
// Console.WriteLine("***ZSS.Trunc: current disk {0}", CurrentSegment);
if (diskNumber >= 99)
{
throw new ArgumentOutOfRangeException("diskNumber");
}
if (rwMode != RwMode.Write)
{
_exceptionPending = true;
throw new ZipException("bad state.");
}
// Seek back in the segmented stream to a (maybe) prior segment.
// Check if it is the same segment. If it is, very simple.
if (diskNumber == CurrentSegment)
{
var x = _innerStream.Seek(offset, SeekOrigin.Begin);
// workitem 10178
Chama.Utils.Ionic.Zip.SharedUtilities.Workaround_Ladybug318918(_innerStream);
return(x);
}
// Seeking back to a prior segment.
// The current segment and any intervening segments must be removed.
// First, close the current segment, and then remove it.
if (_innerStream != null)
{
#if NETCF
_innerStream.Close();
#else
_innerStream.Dispose();
#endif
if (File.Exists(_currentTempName))
{
File.Delete(_currentTempName);
}
}
// Now, remove intervening segments.
for (uint j = CurrentSegment - 1; j > diskNumber; j--)
{
string s = _NameForSegment(j);
// Console.WriteLine("***ZSS.Trunc: removing file {0}", s);
if (File.Exists(s))
{
File.Delete(s);
}
}
// now, open the desired segment. It must exist.
CurrentSegment = diskNumber;
// get a new temp file, try 3 times:
for (int i = 0; i < 3; i++)
{
try
{
_currentTempName = SharedUtilities.InternalGetTempFileName();
// move the .z0x file back to a temp name
File.Move(CurrentName, _currentTempName);
break; // workitem 12403
}
catch (IOException)
{
if (i == 2)
{
throw;
}
}
}
// open it
_innerStream = new FileStream(_currentTempName, FileMode.Open);
var r = _innerStream.Seek(offset, SeekOrigin.Begin);
// workitem 10178
Chama.Utils.Ionic.Zip.SharedUtilities.Workaround_Ladybug318918(_innerStream);
return(r);
}
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;
}
