public Task <bool> IsZip64Async(CancellationToken token)
{
token.ThrowIfCancellationRequested();
if (ZipReadStream == null)
{
throw new SignatureException(Strings.SignedPackageUnableToAccessSignature);
}
using (var reader = new BinaryReader(ZipReadStream, new UTF8Encoding(), leaveOpen: true))
{
return(Task.FromResult(SignedPackageArchiveUtility.IsZip64(reader)));
}
}
/// <summary>
/// Remove a signature from the package, if it exists.
/// </summary>
/// <param name="token">Cancellation token.</param>
public async Task RemoveSignatureAsync(CancellationToken token)
{
token.ThrowIfCancellationRequested();
if (!await IsSignedAsync(token))
{
throw new SignatureException(Strings.SignedPackageNotSignedOnRemove);
}
using (var reader = new BinaryReader(ZipReadStream, SigningSpecifications.Encoding, leaveOpen: true))
using (var writer = new BinaryWriter(_zipWriteStream, SigningSpecifications.Encoding, leaveOpen: true))
{
SignedPackageArchiveUtility.UnsignZip(reader, writer);
}
}
/// <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);
}
