/// <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>
private int InitialRead(byte[] destination, int offset, int count)
{
if (!CanDecompressEntry)
{
throw new ZipException("Library cannot extract this entry. Version required is (" + entry.Version + ")");
}
// Handle encryption if required.
if (entry.IsCrypted)
{
if (password == null)
{
throw new ZipException("No password set.");
}
// Generate and set crypto transform...
var managed = new PkzipClassicManaged();
byte[] key = PkzipClassic.GenerateKeys(ZipStrings.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));
}
}
else
{
inputBuffer.CryptoTransform = null;
}
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>
/// Set the zip file comment.
/// </summary>
/// <param name="comment">
/// The comment text for the entire archive.
/// </param>
/// <exception name ="ArgumentOutOfRangeException">
/// The converted comment is longer than 0xffff bytes.
/// </exception>
public void SetComment(string comment)
{
// TODO: Its not yet clear how to handle unicode comments here.
byte[] commentBytes = ZipStrings.ConvertToArray(comment);
if (commentBytes.Length > 0xffff)
{
throw new ArgumentOutOfRangeException(nameof(comment));
}
zipComment = commentBytes;
}
/// <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
Dispose();
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));
}
var versionRequiredToExtract = (short)inputBuffer.ReadLeShort();
flags = inputBuffer.ReadLeShort();
method = inputBuffer.ReadLeShort();
var 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 = ZipStrings.ConvertToStringExt(flags, buffer);
entry = new ZipEntry(name, versionRequiredToExtract, ZipConstants.VersionMadeBy, (CompressionMethod)method)
{
Flags = flags,
};
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);
}
// Write the local file header
// TODO: ZipHelperStream.WriteLocalHeader is not yet used and needs checking for ZipFile and ZipOuptutStream usage
private void WriteLocalHeader(ZipEntry entry, EntryPatchData patchData)
{
CompressionMethod method = entry.CompressionMethod;
bool headerInfoAvailable = true; // How to get this?
bool patchEntryHeader = false;
WriteLEInt(ZipConstants.LocalHeaderSignature);
WriteLEShort(entry.Version);
WriteLEShort(entry.Flags);
WriteLEShort((byte)method);
WriteLEInt((int)entry.DosTime);
if (headerInfoAvailable == true)
{
WriteLEInt((int)entry.Crc);
if (entry.LocalHeaderRequiresZip64)
{
WriteLEInt(-1);
WriteLEInt(-1);
}
else
{
WriteLEInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
WriteLEInt((int)entry.Size);
}
}
else
{
if (patchData != null)
{
patchData.CrcPatchOffset = stream_.Position;
}
WriteLEInt(0); // Crc
if (patchData != null)
{
patchData.SizePatchOffset = stream_.Position;
}
// For local header both sizes appear in Zip64 Extended Information
if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
{
WriteLEInt(-1);
WriteLEInt(-1);
}
else
{
WriteLEInt(0); // Compressed size
WriteLEInt(0); // Uncompressed size
}
}
byte[] name = ZipStrings.ConvertToArray(entry.Flags, entry.Name);
if (name.Length > 0xFFFF)
{
throw new ZipException("Entry name too long.");
}
var ed = new ZipExtraData(entry.ExtraData);
if (entry.LocalHeaderRequiresZip64 && (headerInfoAvailable || patchEntryHeader))
{
ed.StartNewEntry();
if (headerInfoAvailable)
{
ed.AddLeLong(entry.Size);
ed.AddLeLong(entry.CompressedSize);
}
else
{
ed.AddLeLong(-1);
ed.AddLeLong(-1);
}
ed.AddNewEntry(1);
if (!ed.Find(1))
{
throw new ZipException("Internal error cant find extra data");
}
if (patchData != null)
{
patchData.SizePatchOffset = ed.CurrentReadIndex;
}
}
else
{
ed.Delete(1);
}
byte[] extra = ed.GetEntryData();
WriteLEShort(name.Length);
WriteLEShort(extra.Length);
if (name.Length > 0)
{
stream_.Write(name, 0, name.Length);
}
if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
{
patchData.SizePatchOffset += stream_.Position;
}
if (extra.Length > 0)
{
stream_.Write(extra, 0, extra.Length);
}
}
/// <summary>
/// Finishes the stream. This will write the central directory at the
/// end of the zip file and flush the stream.
/// </summary>
/// <remarks>
/// This is automatically called when the stream is closed.
/// </remarks>
/// <exception cref="System.IO.IOException">
/// An I/O error occurs.
/// </exception>
/// <exception cref="ZipException">
/// Comment exceeds the maximum length<br/>
/// Entry name exceeds the maximum length
/// </exception>
public override void Finish()
{
if (entries == null)
{
return;
}
if (curEntry != null)
{
CloseEntry();
}
long numEntries = entries.Count;
long sizeEntries = 0;
foreach (ZipEntry entry in entries)
{
WriteLeInt(ZipConstants.CentralHeaderSignature);
WriteLeShort((entry.HostSystem << 8) | entry.VersionMadeBy);
WriteLeShort(entry.Version);
WriteLeShort(entry.Flags);
WriteLeShort((short)entry.CompressionMethodForHeader);
WriteLeInt((int)entry.DosTime);
WriteLeInt((int)entry.Crc);
if (entry.IsZip64Forced() ||
(entry.CompressedSize >= uint.MaxValue))
{
WriteLeInt(-1);
}
else
{
WriteLeInt((int)entry.CompressedSize);
}
if (entry.IsZip64Forced() ||
(entry.Size >= uint.MaxValue))
{
WriteLeInt(-1);
}
else
{
WriteLeInt((int)entry.Size);
}
byte[] name = ZipStrings.ConvertToArray(entry.Flags, entry.Name);
if (name.Length > 0xffff)
{
throw new ZipException("Name too long.");
}
var ed = new ZipExtraData(entry.ExtraData);
if (entry.CentralHeaderRequiresZip64)
{
ed.StartNewEntry();
if (entry.IsZip64Forced() ||
(entry.Size >= 0xffffffff))
{
ed.AddLeLong(entry.Size);
}
if (entry.IsZip64Forced() ||
(entry.CompressedSize >= 0xffffffff))
{
ed.AddLeLong(entry.CompressedSize);
}
if (entry.Offset >= 0xffffffff)
{
ed.AddLeLong(entry.Offset);
}
ed.AddNewEntry(1);
}
else
{
ed.Delete(1);
}
if (entry.AESKeySize > 0)
{
AddExtraDataAES(entry, ed);
}
byte[] extra = ed.GetEntryData();
byte[] entryComment =
(entry.Comment != null) ?
ZipStrings.ConvertToArray(entry.Flags, entry.Comment) :
new byte[0];
if (entryComment.Length > 0xffff)
{
throw new ZipException("Comment too long.");
}
WriteLeShort(name.Length);
WriteLeShort(extra.Length);
WriteLeShort(entryComment.Length);
WriteLeShort(0); // disk number
WriteLeShort(0); // internal file attributes
// external file attributes
if (entry.ExternalFileAttributes != -1)
{
WriteLeInt(entry.ExternalFileAttributes);
}
else
{
if (entry.IsDirectory)
{ // mark entry as directory (from nikolam.AT.perfectinfo.com)
WriteLeInt(16);
}
else
{
WriteLeInt(0);
}
}
if (entry.Offset >= uint.MaxValue)
{
WriteLeInt(-1);
}
else
{
WriteLeInt((int)entry.Offset);
}
if (name.Length > 0)
{
baseOutputStream_.Write(name, 0, name.Length);
}
if (extra.Length > 0)
{
baseOutputStream_.Write(extra, 0, extra.Length);
}
if (entryComment.Length > 0)
{
baseOutputStream_.Write(entryComment, 0, entryComment.Length);
}
sizeEntries += ZipConstants.CentralHeaderBaseSize + name.Length + extra.Length + entryComment.Length;
}
using (ZipHelperStream zhs = new ZipHelperStream(baseOutputStream_))
{
zhs.WriteEndOfCentralDirectory(numEntries, sizeEntries, offset, zipComment);
}
entries = null;
}
/// <summary>
/// Starts a new Zip entry. It automatically closes the previous
/// entry if present.
/// All entry elements bar name are optional, but must be correct if present.
/// If the compression method is stored and the output is not patchable
/// the compression for that entry is automatically changed to deflate level 0
/// </summary>
/// <param name="entry">
/// the entry.
/// </param>
/// <exception cref="System.ArgumentNullException">
/// if entry passed is null.
/// </exception>
/// <exception cref="System.IO.IOException">
/// if an I/O error occured.
/// </exception>
/// <exception cref="System.InvalidOperationException">
/// if stream was finished
/// </exception>
/// <exception cref="ZipException">
/// Too many entries in the Zip file<br/>
/// Entry name is too long<br/>
/// Finish has already been called<br/>
/// </exception>
public void PutNextEntry(ZipEntry entry)
{
if (entry == null)
{
throw new ArgumentNullException(nameof(entry));
}
if (entries == null)
{
throw new InvalidOperationException("ZipOutputStream was finished");
}
if (curEntry != null)
{
CloseEntry();
}
if (entries.Count == int.MaxValue)
{
throw new ZipException("Too many entries for Zip file");
}
CompressionMethod method = entry.CompressionMethod;
int compressionLevel = defaultCompressionLevel;
// Clear flags that the library manages internally
entry.Flags &= (int)GeneralBitFlags.UnicodeText;
patchEntryHeader = false;
bool headerInfoAvailable;
// No need to compress - definitely no data.
if (entry.Size == 0)
{
entry.CompressedSize = entry.Size;
entry.Crc = 0;
method = CompressionMethod.Stored;
headerInfoAvailable = true;
}
else
{
headerInfoAvailable = (entry.Size >= 0) && entry.HasCrc && entry.CompressedSize >= 0;
// Switch to deflation if storing isnt possible.
if (method == CompressionMethod.Stored)
{
if (!headerInfoAvailable)
{
if (!CanPatchEntries)
{
// Can't patch entries so storing is not possible.
method = CompressionMethod.Deflated;
compressionLevel = 0;
}
}
else // entry.size must be > 0
{
entry.CompressedSize = entry.Size;
headerInfoAvailable = entry.HasCrc;
}
}
}
if (headerInfoAvailable == false)
{
if (CanPatchEntries == false)
{
// Only way to record size and compressed size is to append a data descriptor
// after compressed data.
// Stored entries of this form have already been converted to deflating.
entry.Flags |= 8;
}
else
{
patchEntryHeader = true;
}
}
if (Password != null)
{
entry.IsCrypted = true;
if (entry.Crc < 0)
{
// Need to append a data descriptor as the crc isnt available for use
// with encryption, the date is used instead. Setting the flag
// indicates this to the decompressor.
entry.Flags |= 8;
}
}
entry.Offset = offset;
entry.CompressionMethod = (CompressionMethod)method;
curMethod = method;
sizePatchPos = -1;
if ((useZip64_ == UseZip64.On) || ((entry.Size < 0) && (useZip64_ == UseZip64.Dynamic)))
{
entry.ForceZip64();
}
// Write the local file header
WriteLeInt(ZipConstants.LocalHeaderSignature);
WriteLeShort(entry.Version);
WriteLeShort(entry.Flags);
WriteLeShort((byte)entry.CompressionMethodForHeader);
WriteLeInt((int)entry.DosTime);
// TODO: Refactor header writing. Its done in several places.
if (headerInfoAvailable)
{
WriteLeInt((int)entry.Crc);
if (entry.LocalHeaderRequiresZip64)
{
WriteLeInt(-1);
WriteLeInt(-1);
}
else
{
WriteLeInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
WriteLeInt((int)entry.Size);
}
}
else
{
if (patchEntryHeader)
{
crcPatchPos = baseOutputStream_.Position;
}
WriteLeInt(0); // Crc
if (patchEntryHeader)
{
sizePatchPos = baseOutputStream_.Position;
}
// For local header both sizes appear in Zip64 Extended Information
if (entry.LocalHeaderRequiresZip64 || patchEntryHeader)
{
WriteLeInt(-1);
WriteLeInt(-1);
}
else
{
WriteLeInt(0); // Compressed size
WriteLeInt(0); // Uncompressed size
}
}
byte[] name = ZipStrings.ConvertToArray(entry.Flags, entry.Name);
if (name.Length > 0xFFFF)
{
throw new ZipException("Entry name too long.");
}
var ed = new ZipExtraData(entry.ExtraData);
if (entry.LocalHeaderRequiresZip64)
{
ed.StartNewEntry();
if (headerInfoAvailable)
{
ed.AddLeLong(entry.Size);
ed.AddLeLong(entry.CompressedSize);
}
else
{
ed.AddLeLong(-1);
ed.AddLeLong(-1);
}
ed.AddNewEntry(1);
if (!ed.Find(1))
{
throw new ZipException("Internal error cant find extra data");
}
if (patchEntryHeader)
{
sizePatchPos = ed.CurrentReadIndex;
}
}
else
{
ed.Delete(1);
}
if (entry.AESKeySize > 0)
{
AddExtraDataAES(entry, ed);
}
byte[] extra = ed.GetEntryData();
WriteLeShort(name.Length);
WriteLeShort(extra.Length);
if (name.Length > 0)
{
baseOutputStream_.Write(name, 0, name.Length);
}
if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
{
sizePatchPos += baseOutputStream_.Position;
}
if (extra.Length > 0)
{
baseOutputStream_.Write(extra, 0, extra.Length);
}
offset += ZipConstants.LocalHeaderBaseSize + name.Length + extra.Length;
// Fix offsetOfCentraldir for AES
if (entry.AESKeySize > 0)
{
offset += entry.AESOverheadSize;
}
// Activate the entry.
curEntry = entry;
crc.Reset();
if (method == CompressionMethod.Deflated)
{
deflater_.Reset();
deflater_.SetLevel(compressionLevel);
}
size = 0;
if (entry.IsCrypted)
{
if (entry.AESKeySize > 0)
{
WriteAESHeader(entry);
}
else
{
if (entry.Crc < 0)
{ // so testing Zip will says its ok
WriteEncryptionHeader(entry.DosTime << 16);
}
else
{
WriteEncryptionHeader(entry.Crc);
}
}
}
}