private static void ReadIntoInstance(ZipFile zf) { zf._entries = new System.Collections.Generic.List <ZipEntry>(); ZipEntry e; if (zf.Verbose) { zf.Output.WriteLine("Reading zip {0}...", zf.Name); } while ((e = ZipEntry.Read(zf.ReadStream)) != null) { if (zf.Verbose) { zf.Output.WriteLine(" {0}", e.FileName); } if (zf._Debug) { System.Console.WriteLine(" ZipFile::Read(): ZipEntry: {0}", e.FileName); } zf._entries.Add(e); } // read the zipfile's central directory structure here. zf._direntries = new System.Collections.Generic.List <ZipDirEntry>(); ZipDirEntry de; while ((de = ZipDirEntry.Read(zf.ReadStream)) != null) { if (zf._Debug) { System.Console.WriteLine(" ZipFile::Read(): ZipDirEntry: {0}", de.FileName); } zf._direntries.Add(de); } // when finished slurping in the zip, close the read stream zf.ReadStream.Close(); zf.ReadStream = null; }
private static bool ReadHeader(System.IO.Stream s, ZipEntry ze) { int signature = ZForge.Zip.Shared.ReadSignature(s); // Return false if this is not a local file header signature. if (ZipEntry.IsNotValidSig(signature)) { s.Seek(-4, System.IO.SeekOrigin.Current); // unread the signature // Getting "not a ZipEntry signature" is not always wrong or an error. // This can happen when walking through a zipfile. After the last compressed entry, // we expect to read a ZipDirEntry signature. When we get this is how we // know we've reached the end of the compressed entries. if (ZipDirEntry.IsNotValidSig(signature)) { throw new Exception(String.Format(" ZipEntry::Read(): Bad signature ({0:X8}) at position 0x{1:X8}", signature, s.Position)); } return(false); } byte[] block = new byte[26]; int n = s.Read(block, 0, block.Length); if (n != block.Length) { return(false); } int i = 0; ze._VersionNeeded = (short)(block[i++] + block[i++] * 256); ze._BitField = (short)(block[i++] + block[i++] * 256); ze._CompressionMethod = (short)(block[i++] + block[i++] * 256); ze._LastModDateTime = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; // the PKZIP spec says that if bit 3 is set (0x0008), then the CRC, Compressed size, and uncompressed size // come directly after the file data. The only way to find it is to scan the zip archive for the signature of // the Data Descriptor, and presume that that signature does not appear in the (compressed) data of the compressed file. if ((ze._BitField & 0x0008) != 0x0008) { ze._Crc32 = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; ze._CompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; ze._UncompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; } else { // the CRC, compressed size, and uncompressed size are stored later in the stream. // here, we advance the pointer. i += 12; } Int16 filenameLength = (short)(block[i++] + block[i++] * 256); Int16 extraFieldLength = (short)(block[i++] + block[i++] * 256); block = new byte[filenameLength]; n = s.Read(block, 0, block.Length); ze._FileNameInArchive = ZForge.Zip.Shared.StringFromBuffer(block, 0, block.Length); // when creating an entry by reading, the LocalFileName is the same as the FileNameInArchivre ze._LocalFileName = ze._FileNameInArchive; ze._Extra = new byte[extraFieldLength]; n = s.Read(ze._Extra, 0, ze._Extra.Length); // transform the time data into something usable ze._LastModified = ZForge.Zip.Shared.PackedToDateTime(ze._LastModDateTime); // actually get the compressed size and CRC if necessary if ((ze._BitField & 0x0008) == 0x0008) { long posn = s.Position; long SizeOfDataRead = ZForge.Zip.Shared.FindSignature(s, ZipConstants.ZipEntryDataDescriptorSignature); if (SizeOfDataRead == -1) { return(false); } // read 3x 4-byte fields (CRC, Compressed Size, Uncompressed Size) block = new byte[12]; n = s.Read(block, 0, block.Length); if (n != 12) { return(false); } i = 0; ze._Crc32 = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; ze._CompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; ze._UncompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; if (SizeOfDataRead != ze._CompressedSize) { throw new Exception("Data format error (bit 3 is set)"); } // seek back to previous position, to read file data s.Seek(posn, System.IO.SeekOrigin.Begin); } return(true); }
/// <summary> /// Reads one entry from the zip directory structure in the zip file. /// </summary> /// <param name="s">the stream from which to read.</param> /// <returns>the entry read from the archive.</returns> public static ZipDirEntry Read(System.IO.Stream s) { int signature = ZForge.Zip.Shared.ReadSignature(s); // return null if this is not a local file header signature if (ZipDirEntry.IsNotValidSig(signature)) { s.Seek(-4, System.IO.SeekOrigin.Current); // 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) { throw new Exception(String.Format(" ZipDirEntry::Read(): Bad signature ({0:X8}) at position 0x{1:X8}", signature, s.Position)); } return null; } byte[] block = new byte[42]; int n = s.Read(block, 0, block.Length); if (n != block.Length) return null; int i = 0; ZipDirEntry zde = new ZipDirEntry(); 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 = (short)(block[i++] + block[i++] * 256); zde._LastModDateTime = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; zde._Crc32 = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; zde._CompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; zde._UncompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; zde._LastModified = ZForge.Zip.Shared.PackedToDateTime(zde._LastModDateTime); Int16 filenameLength = (short)(block[i++] + block[i++] * 256); Int16 extraFieldLength = (short)(block[i++] + block[i++] * 256); Int16 commentLength = (short)(block[i++] + block[i++] * 256); Int16 diskNumber = (short)(block[i++] + block[i++] * 256); Int16 internalFileAttrs = (short)(block[i++] + block[i++] * 256); Int32 externalFileAttrs = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; Int32 Offset = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; block = new byte[filenameLength]; n = s.Read(block, 0, block.Length); zde._FileName = ZForge.Zip.Shared.StringFromBuffer(block, 0, block.Length); zde._Extra = new byte[extraFieldLength]; n = s.Read(zde._Extra, 0, zde._Extra.Length); block = new byte[commentLength]; n = s.Read(block, 0, block.Length); zde._Comment = ZForge.Zip.Shared.StringFromBuffer(block, 0, block.Length); return zde; }
/// <summary> /// Reads one entry from the zip directory structure in the zip file. /// </summary> /// <param name="s">the stream from which to read.</param> /// <returns>the entry read from the archive.</returns> public static ZipDirEntry Read(System.IO.Stream s) { int signature = ZForge.Zip.Shared.ReadSignature(s); // return null if this is not a local file header signature if (ZipDirEntry.IsNotValidSig(signature)) { s.Seek(-4, System.IO.SeekOrigin.Current); // 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) { throw new Exception(String.Format(" ZipDirEntry::Read(): Bad signature ({0:X8}) at position 0x{1:X8}", signature, s.Position)); } return(null); } byte[] block = new byte[42]; int n = s.Read(block, 0, block.Length); if (n != block.Length) { return(null); } int i = 0; ZipDirEntry zde = new ZipDirEntry(); 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 = (short)(block[i++] + block[i++] * 256); zde._LastModDateTime = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; zde._Crc32 = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; zde._CompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; zde._UncompressedSize = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; zde._LastModified = ZForge.Zip.Shared.PackedToDateTime(zde._LastModDateTime); Int16 filenameLength = (short)(block[i++] + block[i++] * 256); Int16 extraFieldLength = (short)(block[i++] + block[i++] * 256); Int16 commentLength = (short)(block[i++] + block[i++] * 256); Int16 diskNumber = (short)(block[i++] + block[i++] * 256); Int16 internalFileAttrs = (short)(block[i++] + block[i++] * 256); Int32 externalFileAttrs = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; Int32 Offset = block[i++] + block[i++] * 256 + block[i++] * 256 * 256 + block[i++] * 256 * 256 * 256; block = new byte[filenameLength]; n = s.Read(block, 0, block.Length); zde._FileName = ZForge.Zip.Shared.StringFromBuffer(block, 0, block.Length); zde._Extra = new byte[extraFieldLength]; n = s.Read(zde._Extra, 0, zde._Extra.Length); block = new byte[commentLength]; n = s.Read(block, 0, block.Length); zde._Comment = ZForge.Zip.Shared.StringFromBuffer(block, 0, block.Length); return(zde); }