public static bool IsZip64(BinaryReader reader)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
var endOfCentralDirectoryRecord = EndOfCentralDirectoryRecord.Read(reader);
if (endOfCentralDirectoryRecord.NumberOfThisDisk != endOfCentralDirectoryRecord.NumberOfTheDiskWithTheStartOfTheCentralDirectory)
{
return(false);
}
var offset = endOfCentralDirectoryRecord.OffsetFromStart - Zip64EndOfCentralDirectoryLocator.SizeInBytes;
if (offset >= 0)
{
reader.BaseStream.Seek(offset, SeekOrigin.Begin);
if (Zip64EndOfCentralDirectoryLocator.Exists(reader))
{
return(true);
}
}
reader.BaseStream.Seek(endOfCentralDirectoryRecord.OffsetOfStartOfCentralDirectory, SeekOrigin.Begin);
CentralDirectoryHeader centralDirectoryHeader;
while (CentralDirectoryHeader.TryRead(reader, out centralDirectoryHeader))
{
if (HasZip64ExtendedInformationExtraField(centralDirectoryHeader))
{
return(true);
}
if (centralDirectoryHeader.DiskNumberStart != endOfCentralDirectoryRecord.NumberOfThisDisk)
{
continue;
}
var savedPosition = reader.BaseStream.Position;
reader.BaseStream.Position = centralDirectoryHeader.RelativeOffsetOfLocalHeader;
LocalFileHeader localFileHeader;
if (LocalFileHeader.TryRead(reader, out localFileHeader) &&
HasZip64ExtendedInformationExtraField(localFileHeader))
{
return(true);
}
reader.BaseStream.Position = savedPosition;
}
return(false);
}
/// <summary>
/// Read ZIP's offsets and positions of offsets.
/// </summary>
/// <param name="reader">binary reader to zip archive</param>
/// <returns>metadata with offsets and positions for entries</returns>
public static SignedPackageArchiveMetadata ReadSignedArchiveMetadata(BinaryReader reader)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
var metadata = new SignedPackageArchiveMetadata()
{
StartOfFileHeaders = reader.BaseStream.Length
};
var endOfCentralDirectoryRecord = EndOfCentralDirectoryRecord.Read(reader);
metadata.EndOfCentralDirectoryRecordPosition = endOfCentralDirectoryRecord.OffsetFromStart;
reader.BaseStream.Seek(endOfCentralDirectoryRecord.OffsetOfStartOfCentralDirectory, SeekOrigin.Begin);
// Read central directory records
var centralDirectoryRecords = new List <CentralDirectoryHeaderMetadata>();
CentralDirectoryHeader header;
while (CentralDirectoryHeader.TryRead(reader, out header))
{
if (header.RelativeOffsetOfLocalHeader < metadata.StartOfFileHeaders)
{
metadata.StartOfFileHeaders = header.RelativeOffsetOfLocalHeader;
}
var isPackageSignatureFile = SignedPackageArchiveUtility.IsPackageSignatureFileEntry(
header.FileName,
header.GeneralPurposeBitFlag);
var centralDirectoryMetadata = new CentralDirectoryHeaderMetadata()
{
IsPackageSignatureFile = isPackageSignatureFile,
HeaderSize = header.GetSizeInBytes(),
OffsetToFileHeader = header.RelativeOffsetOfLocalHeader,
Position = header.OffsetFromStart
};
centralDirectoryRecords.Add(centralDirectoryMetadata);
}
if (centralDirectoryRecords.Count == 0)
{
throw new InvalidDataException(Strings.ErrorInvalidPackageArchive);
}
var lastCentralDirectoryRecord = centralDirectoryRecords.Last();
metadata.EndOfCentralDirectory = lastCentralDirectoryRecord.Position + lastCentralDirectoryRecord.HeaderSize;
metadata.CentralDirectoryHeaders = centralDirectoryRecords;
UpdateSignedPackageArchiveMetadata(reader, metadata);
return(metadata);
}
private static bool HasZip64ExtendedInformationExtraField(CentralDirectoryHeader header)
{
IReadOnlyList <ExtraField> extraFields;
if (ExtraField.TryRead(header, out extraFields))
{
return(extraFields.Any(extraField => extraField is Zip64ExtendedInformationExtraField));
}
return(false);
}
/// <summary>
/// Utility method to know if a zip archive is signed.
/// </summary>
/// <param name="reader">Binary reader pointing to a zip archive.</param>
/// <returns>true if the given archive is signed</returns>
public static bool IsSigned(BinaryReader reader)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
try
{
var endOfCentralDirectoryRecord = EndOfCentralDirectoryRecord.Read(reader);
// Look for signature central directory record
reader.BaseStream.Seek(endOfCentralDirectoryRecord.OffsetOfStartOfCentralDirectory, SeekOrigin.Begin);
CentralDirectoryHeader centralDirectoryHeader;
while (CentralDirectoryHeader.TryRead(reader, out centralDirectoryHeader))
{
if (IsPackageSignatureFileEntry(
centralDirectoryHeader.FileName,
centralDirectoryHeader.GeneralPurposeBitFlag))
{
// Go to local file header
reader.BaseStream.Seek(centralDirectoryHeader.RelativeOffsetOfLocalHeader, SeekOrigin.Begin);
// Make sure local file header exists
LocalFileHeader localFileHeader;
if (!LocalFileHeader.TryRead(reader, out localFileHeader))
{
throw new InvalidDataException(Strings.ErrorInvalidPackageArchive);
}
return(IsPackageSignatureFileEntry(
localFileHeader.FileName,
localFileHeader.GeneralPurposeBitFlag));
}
}
}
// Ignore any exception. If something is thrown it means the archive is either not valid or not signed
catch { }
return(false);
}
private static UnsignedPackageArchiveMetadata ReadUnsignedArchiveMetadata(BinaryReader reader)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
var endOfCentralDirectoryRecord = EndOfCentralDirectoryRecord.Read(reader);
var endOfCentralDirectoryRecordPosition = endOfCentralDirectoryRecord.OffsetFromStart;
reader.BaseStream.Seek(endOfCentralDirectoryRecord.OffsetOfStartOfCentralDirectory, SeekOrigin.Begin);
var centralDirectoryRecords = new List <CentralDirectoryHeaderMetadata>();
CentralDirectoryHeader header;
while (CentralDirectoryHeader.TryRead(reader, out header))
{
var centralDirectoryMetadata = new CentralDirectoryHeaderMetadata()
{
Position = header.OffsetFromStart,
OffsetToLocalFileHeader = header.RelativeOffsetOfLocalHeader,
HeaderSize = header.GetSizeInBytes(),
};
centralDirectoryRecords.Add(centralDirectoryMetadata);
}
if (centralDirectoryRecords.Count == 0)
{
throw new InvalidDataException(Strings.ErrorInvalidPackageArchive);
}
var lastCentralDirectoryRecord = centralDirectoryRecords.Last();
var endOfCentralDirectoryPosition = lastCentralDirectoryRecord.Position + lastCentralDirectoryRecord.HeaderSize;
var endOfLocalFileHeadersPosition = centralDirectoryRecords.Min(record => record.Position);
UpdateLocalFileHeadersTotalSize(centralDirectoryRecords, endOfLocalFileHeadersPosition);
return(new UnsignedPackageArchiveMetadata(endOfLocalFileHeadersPosition, endOfCentralDirectoryPosition));
}
internal static bool TryRead(BinaryReader reader, out CentralDirectoryHeader header)
{
header = null;
var signature = reader.ReadUInt32();
if (signature != Signature)
{
reader.BaseStream.Seek(offset: -sizeof(uint), origin: SeekOrigin.Current);
return(false);
}
header = new CentralDirectoryHeader();
header.OffsetFromStart = reader.BaseStream.Position - sizeof(uint);
header.VersionMadeBy = reader.ReadUInt16();
header.VersionNeededToExtract = reader.ReadUInt16();
header.GeneralPurposeBitFlag = reader.ReadUInt16();
header.CompressionMethod = reader.ReadUInt16();
header.LastModFileTime = reader.ReadUInt16();
header.LastModFileDate = reader.ReadUInt16();
header.Crc32 = reader.ReadUInt32();
header.CompressedSize = reader.ReadUInt32();
header.UncompressedSize = reader.ReadUInt32();
header.FileNameLength = reader.ReadUInt16();
header.ExtraFieldLength = reader.ReadUInt16();
header.FileCommentLength = reader.ReadUInt16();
header.DiskNumberStart = reader.ReadUInt16();
header.InternalFileAttributes = reader.ReadUInt16();
header.ExternalFileAttributes = reader.ReadUInt32();
header.RelativeOffsetOfLocalHeader = reader.ReadUInt32();
header.FileName = reader.ReadBytes(header.FileNameLength);
header.ExtraField = reader.ReadBytes(header.ExtraFieldLength);
header.FileComment = reader.ReadBytes(header.FileCommentLength);
return(true);
}
internal static bool TryRead(CentralDirectoryHeader header, out IReadOnlyList <ExtraField> extraFields)
{
extraFields = null;
if (header.ExtraFieldLength == 0)
{
return(false);
}
var readUncompressedFileSize = header.UncompressedSize == ZipConstants.Mask32Bit;
var readCompressedFileSize = header.CompressedSize == ZipConstants.Mask32Bit;
var readRelativeOffsetOfLocalHeader = header.RelativeOffsetOfLocalHeader == ZipConstants.Mask32Bit;
var readDiskNumberStart = header.DiskNumberStart == ZipConstants.Mask16Bit;
return(TryRead(
header.ExtraField,
readUncompressedFileSize,
readCompressedFileSize,
readRelativeOffsetOfLocalHeader,
readDiskNumberStart,
out extraFields));
}
/// <summary>
/// Utility method to know if a zip archive is signed.
/// </summary>
/// <param name="reader">Binary reader pointing to a zip archive.</param>
/// <returns>true if the given archive is signed</returns>
private static bool IsSigned(BinaryReader reader)
{
try
{
var endOfCentralDirectoryRecord = EndOfCentralDirectoryRecord.Read(reader);
// Look for signature central directory record
reader.BaseStream.Seek(endOfCentralDirectoryRecord.OffsetOfStartOfCentralDirectory, SeekOrigin.Begin);
CentralDirectoryHeader header;
while (CentralDirectoryHeader.TryRead(reader, out header))
{
var isUtf8 = IsUtf8(header.GeneralPurposeBitFlag);
var fileName = GetString(header.FileName, isUtf8);
if (string.Equals(fileName, _signingSpecification.SignaturePath, StringComparison.Ordinal))
{
// Go to local file header
reader.BaseStream.Seek(header.RelativeOffsetOfLocalHeader, SeekOrigin.Begin);
// Make sure file header exists there
var fileHeaderSignature = reader.ReadUInt32();
if (fileHeaderSignature != LocalFileHeader.Signature)
{
throw new InvalidDataException(Strings.ErrorInvalidPackageArchive);
}
return(true);
}
}
}
// Ignore any exception. If something is thrown it means the archive is either not valid or not signed
catch { }
return(false);
}
/// <summary>
/// Read ZIP's offsets and positions of offsets.
/// </summary>
/// <param name="reader">binary reader to zip archive</param>
/// <returns>metadata with offsets and positions for entries</returns>
public static SignedPackageArchiveMetadata ReadSignedArchiveMetadata(BinaryReader reader)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
var metadata = new SignedPackageArchiveMetadata()
{
StartOfLocalFileHeaders = reader.BaseStream.Length
};
var endOfCentralDirectoryRecord = EndOfCentralDirectoryRecord.Read(reader);
var endOfCentralDirectoryRecordPosition = endOfCentralDirectoryRecord.OffsetFromStart;
reader.BaseStream.Seek(endOfCentralDirectoryRecord.OffsetOfStartOfCentralDirectory, SeekOrigin.Begin);
var centralDirectoryRecords = new List <CentralDirectoryHeaderMetadata>();
var packageSignatureFileMetadataIndex = -1;
var index = 0;
while (CentralDirectoryHeader.TryRead(reader, out var header))
{
metadata.StartOfLocalFileHeaders = Math.Min(metadata.StartOfLocalFileHeaders, header.RelativeOffsetOfLocalHeader);
var isPackageSignatureFile = SignedPackageArchiveUtility.IsPackageSignatureFileEntry(
header.FileName,
header.GeneralPurposeBitFlag);
if (isPackageSignatureFile)
{
if (packageSignatureFileMetadataIndex != -1)
{
throw new SignatureException(NuGetLogCode.NU3005, Strings.MultiplePackageSignatureFiles);
}
packageSignatureFileMetadataIndex = index;
}
var centralDirectoryMetadata = new CentralDirectoryHeaderMetadata()
{
Position = header.OffsetFromStart,
OffsetToLocalFileHeader = header.RelativeOffsetOfLocalHeader,
IsPackageSignatureFile = isPackageSignatureFile,
HeaderSize = header.GetSizeInBytes(),
IndexInHeaders = index
};
centralDirectoryRecords.Add(centralDirectoryMetadata);
++index;
}
if (centralDirectoryRecords.Count == 0)
{
throw new InvalidDataException(Strings.ErrorInvalidPackageArchive);
}
if (packageSignatureFileMetadataIndex == -1)
{
throw new SignatureException(NuGetLogCode.NU3005, Strings.NoPackageSignatureFile);
}
var lastCentralDirectoryRecord = centralDirectoryRecords.Last();
var endOfCentralDirectoryPosition = lastCentralDirectoryRecord.Position + lastCentralDirectoryRecord.HeaderSize;
var endOfLocalFileHeadersPosition = GetEndOfLocalFileHeadersPosition(reader, centralDirectoryRecords);
metadata.EndOfCentralDirectory = lastCentralDirectoryRecord.Position + lastCentralDirectoryRecord.HeaderSize;
metadata.CentralDirectoryHeaders = centralDirectoryRecords;
metadata.EndOfLocalFileHeaders = endOfLocalFileHeadersPosition;
metadata.SignatureCentralDirectoryHeaderIndex = packageSignatureFileMetadataIndex;
AssertSignatureEntryMetadata(reader, metadata);
return(metadata);
}