public Record[] ProcessHandshakeMessages(ProtocolVersion version,
HandshakeMessage[] messages,
int maxFragmentLength)
{
List<Record> records = new List<Record>();
// Write all handshake data to memory stream
MemoryStream memStream = new MemoryStream();
for (int i = 0; i < messages.Length; i++)
{
byte[] msgBytes = messages[i].Encode();
memStream.Write(msgBytes, 0, msgBytes.Length);
}
// Read handshake data from memory stream one at a time
memStream.Position = 0;
while (memStream.Position < memStream.Length)
{
long fragmentLength = Math.Min(memStream.Length - memStream.Position, maxFragmentLength);
byte[] fragment = new byte[fragmentLength];
memStream.Read(fragment, 0, fragment.Length);
Record record = new Record(RecordType.Handshake, version);
record.Fragment = fragment;
records.Add(record);
}
return records.ToArray();
}
public async Task SendAsync(Record[] records, CancellationToken token)
{
if (records == null)
{
throw new ArgumentNullException(nameof(records));
}
// Make sure fragments are not too long
foreach (Record record in records)
{
if (record.Fragment.Length > MAX_RECORD_SIZE)
{
throw new RecordTooLargeException("Trying to send a too large fragment: " + record.Fragment.Length);
}
Log.Debug(">> RECORD TX, Type {0}, Len {1}.", record.Type, record.FragmentLength);
var buffer = record.GetBytes();
try
{
await this.innerStream.WriteAsync(buffer, 0, buffer.Length, token);
break;
}
catch (Exception ex)
{
Log.Error("Send failed: {0}", ex.Message);
throw;
}
}
}
public Record[] ProcessOutputData(ProtocolVersion version, byte type, byte[] data, int maxFragmentLength)
{
List<Record> records = new List<Record>();
// Read handshake data from memory stream one at a time
MemoryStream memStream = new MemoryStream(data);
while (memStream.Position < memStream.Length)
{
long fragmentLength = Math.Min(memStream.Length - memStream.Position, maxFragmentLength);
byte[] fragment = new byte[fragmentLength];
memStream.Read(fragment, 0, fragment.Length);
Record record = new Record((RecordType)type, version);
record.Fragment = fragment;
records.Add(record);
}
return records.ToArray();
}
public HandshakeMessage[] ProcessHandshakeRecord(ProtocolVersion version,
Record record)
{
List<HandshakeMessage> ret = new List<HandshakeMessage>();
// Write record to input stream and attempt to parse a handshake message
_inputStream.Write(record.Fragment, 0, record.Fragment.Length);
while (_inputStream.Length - _inputtedBytes >= 4)
{
byte[] inputBuffer = _inputStream.GetBuffer();
int dataLength = (inputBuffer[_inputtedBytes + 1] << 16) |
(inputBuffer[_inputtedBytes + 2] << 8) |
inputBuffer[_inputtedBytes + 3];
// Check that if we have enough data to read message now
if (4 + dataLength > _inputStream.Length - _inputtedBytes)
break;
byte[] msgData = new byte[4 + dataLength];
long writePosition = _inputStream.Position;
// Read message data from inputStream
_inputStream.Position = _inputtedBytes;
_inputStream.Read(msgData, 0, msgData.Length);
_inputStream.Position = writePosition;
_inputtedBytes += msgData.Length;
// Add resulting handshake message to the results
ret.Add(HandshakeMessage.GetInstance(version, msgData));
}
if (_inputtedBytes == _inputStream.Length)
{
// Reset stream to save memory
_inputStream.Position = 0;
_inputStream.SetLength(0);
_inputtedBytes = 0;
}
return ret.ToArray();
}
private void ProcessUnknownRecord(Record record)
{
throw new InvalidOperationException("Unknown record");
}
private async Task ProcessSendFatalAlert(Alert alert, CancellationToken token)
{
this.logger?.Warn("Processing fatal alert...");
try
{
// Create and encrypt the alert record
Record record = new Record(RecordType.Alert, this._handshakeSession.NegotiatedVersion, alert.GetBytes());
this._recordHandler.ProcessOutputRecord(record);
// Attempt sending the alert record
await this._recordStream.SendAsync(new Record[] { record }, token);
}
catch (Exception ex)
{
this.logger?.Error("Processing fatal alert failed: {0}", ex.Message);
}
finally
{
if (this._recordStream != null)
{
this.logger?.Info("Closing record stream...");
this._recordStream.Flush();
this._recordStream.Close();
}
}
}
private void ProcessAlertRecord(Record record)
{
// TODO: Received an alert, handle correctly
Alert alert = new Alert(record.Fragment);
this.logger?.Debug("Received an alert: " + alert.Description);
if (alert.Level == AlertLevel.Fatal)
{
// Fatal alerts don't need close notify
_recordStream.Close();
throw new Exception("Received a fatal alert");
}
}
private async Task SendServerChangeCipherSpec(CancellationToken token)
{
this.logger?.Debug("Sending change cipher spec to client...");
// Create the change cipher spec protocol packet
// NOTE: this has to be before recordHandler.ChangeLocalState since it uses the old state
var record = new Record(
RecordType.ChangeCipherSpec,
this._handshakeSession.NegotiatedVersion,
new byte[] { 0x01 });
this._recordHandler.ProcessOutputRecord(record);
// NOTE: keep this before recordHandler.ChangeLocalState since it may generate masterSecret
this._handshakeSession.LocalChangeCipherSpec();
// Change cipher suite in record handler and handle it in handshake session
this._recordHandler.SetCipherSuite(this._handshakeSession.CipherSuite, this._handshakeSession.ConnectionState);
this._recordHandler.ChangeLocalState();
// Send the change cipher spec protocol packet
await this._recordStream.SendAsync(new[] { record }, token);
}
public async Task<Record[]> ReceiveAsync(CancellationToken token)
{
var records = new List<Record>();
var readBuffer = new byte[MAX_RECORD_SIZE];
var needsMoreData = true;
while (!token.IsCancellationRequested)
{
if (needsMoreData)
{
// hook to combine token.cancel with stream.close, otherwise ReadAsync never returns
using (token.Register(this.innerStream.Close))
{
try
{
var readBytes = await this.innerStream.ReadAsync(readBuffer, 0, readBuffer.Length, token);
if (readBytes < 1)
{
continue;
}
this.rcvBuffer.AddRange(readBuffer.Take(readBytes));
}
catch (Exception e)
{
if (token.IsCancellationRequested)
{
throw new OperationCanceledException("Read was cancelled");
}
Log.Error("Read failed: ", e.Message);
}
}
}
// do not inspect buffer if there is not even a packet header
if (this.rcvBuffer.Count < 5)
{
await Task.Delay(5, token);
continue;
}
// We require the fragment bytes
int fragmentLength = (this.rcvBuffer[3] << 8) | this.rcvBuffer[4];
if (fragmentLength > this.rcvBuffer.Count + 5)
{
// read more data
needsMoreData = true;
continue;
}
needsMoreData = false;
// Construct the TLSRecord returned as result
var recordBuffer = this.rcvBuffer.Take(5 + fragmentLength).ToArray();
var record = new Record(recordBuffer);
Log.Debug("<< RECORD RX, Type {0}, Fragment Len {1} Seq {2}.", record.Type, record.FragmentLength, record.SequenceNumber);
Buffer.BlockCopy(recordBuffer, 5, record.Fragment, 0, fragmentLength);
records.Add(record);
// remove record from input buffer
this.rcvBuffer.RemoveRange(0, 5 + fragmentLength);
if (this.rcvBuffer.Count == 0)
{
// return records
break;
}
}
return records.ToArray();
}