static IHidOutputReport ToOutputReport(IHidDevice device, ContinuationPacket continuation)
{
var report = device.CreateOutputReport();
continuation.WriteTo(report.Data);
return(report);
}
public static async Task <FidoU2FHidMessage> ReadFidoU2FHidMessageAsync([NotNull] this IHidDevice device, CancellationToken cancellationToken)
{
if (device == null)
{
throw new ArgumentNullException(nameof(device));
}
var initReport = await device.GetInputReportAsync(cancellationToken);
var init = InitializationPacket.ReadFrom(initReport.Data);
var dataSizeReceived = init.Data.Count;
var continuations = new List <ContinuationPacket>();
byte index = 0;
while (dataSizeReceived < init.PayloadLength)
{
var continuationReport = await device.GetInputReportAsync(cancellationToken);
var continuation = ContinuationPacket.ReadFrom(continuationReport.Data, init.PayloadLength - dataSizeReceived);
if (continuation.PaketSequence != index)
{
throw new InvalidSequenceNumberException(continuationReport.Data,
$"The sequence number isn't the expected one, expected {index} but read {continuation.PaketSequence}");
}
continuations.Add(continuation);
dataSizeReceived += continuation.Data.Count;
index += 1;
}
return(BuildMessage(init, continuations));
}
static Tuple <InitializationPacket, List <ContinuationPacket> > MakeOutputPackets(
int paketLength, FidoU2FHidMessage message)
{
var availableInInit = paketLength - InitializationPacket.NoDataSize;
var availableInContinuation = paketLength - ContinuationPacket.NoDataSize;
var data = message.Data;
var init = new InitializationPacket
{
ChannelIdentifier = message.Channel,
CommandIdentifier = (byte)message.Command,
PayloadLength = (ushort)data.Count,
Data = new ArraySegment <byte>(data.Array, data.Offset,
Math.Min(data.Count, availableInInit))
};
var sizeHandled = init.Data.Count;
var continuations = new List <ContinuationPacket>();
byte sequence = 0;
while (sizeHandled < data.Count)
{
var continuation = new ContinuationPacket
{
ChannelIdentifier = message.Channel,
PaketSequence = sequence,
Data = new ArraySegment <byte>(data.Array, data.Offset + sizeHandled,
Math.Min(data.Count - sizeHandled, availableInContinuation))
};
continuations.Add(continuation);
sizeHandled += continuation.Data.Count;
sequence += 1;
}
return(Tuple.Create(init, continuations));
}