public static ZipCrypto ForRead(string password, ZipEntry e)
{
System.IO.Stream s = e._archiveStream;
e._WeakEncryptionHeader = new byte[12];
byte[] eh = e._WeakEncryptionHeader;
ZipCrypto z = new ZipCrypto();
if (password == null)
{
throw new Exception("This entry requires a password.");
}
z.InitCipher(password);
ZipEntry.ReadWeakEncryptionHeader(s, eh);
// Decrypt the header. This has a side effect of "further initializing the
// encryption keys" in the traditional zip encryption.
byte[] DecryptedHeader = z.DecryptMessage(eh, eh.Length);
// CRC check
// According to the pkzip spec, the final byte in the decrypted header
// is the highest-order byte in the CRC. We check it here.
if (DecryptedHeader[11] != (byte)((e._Crc32 >> 24) & 0xff))
{
// In the case that bit 3 of the general purpose bit flag is set to
// indicate the presence of an 'Extended File Header' or a 'data
// descriptor' (signature 0x08074b50), the last byte of the decrypted
// header is sometimes compared with the high-order byte of the
// lastmodified time, rather than the high-order byte of the CRC, to
// verify the password.
//
// This is not documented in the PKWare Appnote.txt. It was
// discovered this by analysis of the Crypt.c source file in the
// InfoZip library http://www.info-zip.org/pub/infozip/
//
// The reason for this is that the CRC for a file cannot be known
// until the entire contents of the file have been streamed. This
// means a tool would have to read the file content TWICE in its
// entirety in order to perform PKZIP encryption - once to compute
// the CRC, and again to actually encrypt.
//
// This is so important for performance that using the timeblob as
// the verification should be the standard practice for DotNetZip
// when using PKZIP encryption. This implies that bit 3 must be
// set. The downside is that some tools still cannot cope with ZIP
// files that use bit 3. Therefore, DotNetZip DOES NOT force bit 3
// when PKZIP encryption is in use, and instead, reads the stream
// twice.
//
if ((e._BitField & 0x0008) != 0x0008)
{
throw new Exception("The password did not match.");
}
else if (DecryptedHeader[11] != (byte)((e._TimeBlob >> 8) & 0xff))
{
throw new Exception("The password did not match.");
}
// We have a good password.
}
else
{
// A-OK
}
return(z);
}
internal static ExtractProgressEventArgs AfterExtractEntry(string archiveName, ZipEntry entry, string extractLocation)
{
var x = new ExtractProgressEventArgs
{
ArchiveName = archiveName,
EventType = ZipProgressEventType.Extracting_AfterExtractEntry,
CurrentEntry = entry,
_target = extractLocation,
};
return(x);
}
/// <summary>
/// Constructor for the ExtractProgressEventArgs.
/// </summary>
/// <param name="archiveName">the name of the zip archive.</param>
/// <param name="before">whether this is before saving the entry, or after</param>
/// <param name="entriesTotal">The total number of entries in the zip archive.</param>
/// <param name="entriesExtracted">Number of entries that have been extracted.</param>
/// <param name="entry">The entry involved in the event.</param>
/// <param name="extractLocation">The location to which entries are extracted.</param>
internal ExtractProgressEventArgs(string archiveName, bool before, int entriesTotal, int entriesExtracted, ZipEntry entry, string extractLocation)
: base(archiveName, (before) ? ZipProgressEventType.Extracting_BeforeExtractEntry : ZipProgressEventType.Extracting_AfterExtractEntry)
{
this.EntriesTotal = entriesTotal;
this.CurrentEntry = entry;
this._entriesExtracted = entriesExtracted;
this._target = extractLocation;
}
/// <summary>
/// Constructor for the SaveProgressEventArgs.
/// </summary>
/// <param name="archiveName">the name of the zip archive.</param>
/// <param name="before">whether this is before saving the entry, or after</param>
/// <param name="entriesTotal">The total number of entries in the zip archive.</param>
/// <param name="entriesSaved">Number of entries that have been saved.</param>
/// <param name="entry">The entry involved in the event.</param>
internal SaveProgressEventArgs(string archiveName, bool before, int entriesTotal, int entriesSaved, ZipEntry entry)
: base(archiveName, (before) ? ZipProgressEventType.Saving_BeforeWriteEntry : ZipProgressEventType.Saving_AfterWriteEntry)
{
this.EntriesTotal = entriesTotal;
this.CurrentEntry = entry;
this._entriesSaved = entriesSaved;
}
// 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 (Exception) { }
zf.OnReadCompleted();
}
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();
}
