private static IEnumerable <byte> Build(SystemWrapper.IO.IFileInfoWrap file)
{
var sha = new SHA256Managed();
var createDate = Encoding.ASCII.GetBytes(file.CreationTime.ToString(CultureInfo.InvariantCulture));
var createDateChecksum = sha.ComputeHash(createDate);
var modifyDate = Encoding.ASCII.GetBytes(file.LastWriteTime.ToString(CultureInfo.InvariantCulture));
var modifyDateChecksum = sha.ComputeHash(modifyDate);
var fileName = Encoding.ASCII.GetBytes(file.Name);
var fileNameChecksum = sha.ComputeHash(fileName);
// TODO: Verifiy if including file data (expensive operation) is necessary
byte[] fileChecksum;
using (var fileStream = file.Open(FileMode.Open, FileAccess.Read, FileShare.Read))
{
using (var bufferedStream = new BufferedStream(fileStream.StreamInstance, 64 * 1000))
{
fileChecksum = sha.ComputeHash(bufferedStream);
}
}
var networkId = Encoding.ASCII.GetBytes(NetworkUtilities.GetNetworkId());
var networkIdChecksum = sha.ComputeHash(networkId);
var checksumSum = createDateChecksum.Concat(modifyDateChecksum).Concat(fileNameChecksum).Concat(fileChecksum).Concat(networkIdChecksum);
var checksum = sha.ComputeHash(checksumSum.ToArray());
return(checksum);
}