/// <summary>
/// Creates a central file header from the information in a local file header.
/// </summary>
/// <param name="localFileHeader">Local file header to </param>
public ZipFileHeader(ZipFileHeader localFileHeader)
{
if (localFileHeader.central)
{
throw new ArgumentException();
}
this.central = true;
this.compressionMethod = localFileHeader.compressionMethod;
this.fileName = localFileHeader.fileName;
this.fileComment = localFileHeader.fileComment;
this.flags = localFileHeader.flags;
this.externalFileAttrs = localFileHeader.externalFileAttrs;
this.internalFileAttrs = localFileHeader.internalFileAttrs;
this.lastModDate = localFileHeader.lastModDate;
this.lastModTime = localFileHeader.lastModTime;
this.crc32 = localFileHeader.crc32;
if (this.zip64)
{
this.versionMadeBy = 45;
this.versionNeeded = 45;
this.compressedSize = UInt32.MaxValue;
this.uncompressedSize = UInt32.MaxValue;
this.diskStart = UInt16.MaxValue;
ZipExtraFileField field = new ZipExtraFileField();
field.fieldType = ZipExtraFileFieldType.ZIP64;
field.SetZip64Data(localFileHeader.compressedSize, localFileHeader.uncompressedSize, localFileHeader.localHeaderOffset, localFileHeader.diskStart);
this.extraFields = new ZipExtraFileField[] { field };
}
else
{
this.versionMadeBy = 20;
this.versionNeeded = 20;
this.localHeaderOffset = localFileHeader.localHeaderOffset;
this.compressedSize = localFileHeader.compressedSize;
this.uncompressedSize = localFileHeader.uncompressedSize;
}
}
public bool Read(Stream stream)
{
if (stream.Length - stream.Position < (this.central ? CFH_FIXEDSIZE : LFH_FIXEDSIZE))
{
return(false);
}
BinaryReader reader = new BinaryReader(stream);
uint sig = reader.ReadUInt32();
if (sig == SPANSIG || sig == SPANSIG2)
{
// Spanned zip files may optionally begin with a special marker.
// Just ignore it and move on.
sig = reader.ReadUInt32();
}
if (sig != (this.central ? CFHSIG : LFHSIG))
{
return(false);
}
this.versionMadeBy = (this.central ? reader.ReadUInt16() : (ushort)0);
this.versionNeeded = reader.ReadUInt16();
this.flags = (ZipFileFlags)reader.ReadUInt16();
this.compressionMethod = (ZipCompressionMethod)reader.ReadUInt16();
this.lastModTime = reader.ReadInt16();
this.lastModDate = reader.ReadInt16();
this.crc32 = reader.ReadUInt32();
this.compressedSize = reader.ReadUInt32();
this.uncompressedSize = reader.ReadUInt32();
this.zip64 = this.uncompressedSize == UInt32.MaxValue;
int fileNameLength = reader.ReadUInt16();
int extraFieldLength = reader.ReadUInt16();
int fileCommentLength;
if (this.central)
{
fileCommentLength = reader.ReadUInt16();
this.diskStart = reader.ReadUInt16();
this.internalFileAttrs = reader.ReadUInt16();
this.externalFileAttrs = reader.ReadUInt32();
this.localHeaderOffset = reader.ReadUInt32();
}
else
{
fileCommentLength = 0;
this.diskStart = 0;
this.internalFileAttrs = 0;
this.externalFileAttrs = 0;
this.localHeaderOffset = 0;
}
if (stream.Length - stream.Position < fileNameLength + extraFieldLength + fileCommentLength)
{
return(false);
}
Encoding headerEncoding = ((this.flags | ZipFileFlags.UTF8) != 0 ? Encoding.UTF8 : Encoding.GetEncoding(CultureInfo.CurrentCulture.TextInfo.OEMCodePage));
byte[] fileNameBytes = reader.ReadBytes(fileNameLength);
this.fileName = headerEncoding.GetString(fileNameBytes);
List <ZipExtraFileField> fields = new List <ZipExtraFileField>();
while (extraFieldLength > 0)
{
ZipExtraFileField field = new ZipExtraFileField();
if (!field.Read(stream, ref extraFieldLength))
{
return(false);
}
fields.Add(field);
if (field.fieldType == ZipExtraFileFieldType.ZIP64)
{
this.zip64 = true;
}
}
this.extraFields = fields.ToArray();
byte[] fileCommentBytes = reader.ReadBytes(fileCommentLength);
this.fileComment = headerEncoding.GetString(fileCommentBytes);
return(true);
}
