private void SendChangeCipherSpec()
{
int size = 1;
int responseSize = DTLSRecord.RECORD_OVERHEAD + size;
byte[] response = new byte[responseSize];
DTLSRecord record = new DTLSRecord
{
RecordType = TRecordType.ChangeCipherSpec,
Epoch = _Epoch,
SequenceNumber = NextSequenceNumber(),
Fragment = new byte[size]
};
record.Fragment[0] = 1;
if (_Version != null)
{
record.Version = _Version;
}
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = _ServerEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
ChangeEpoch();
}
private async Task _SendAlertAsync(TAlertLevel alertLevel, TAlertDescription alertDescription, TimeSpan timeout)
{
if (this._Socket == null)
{
throw new Exception("Soket Cannot be Null");
}
var record = new DTLSRecord
{
RecordType = TRecordType.Alert,
Epoch = _Epoch,
SequenceNumber = this._NextSequenceNumber(),
Version = this._Version
};
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
var data = new byte[2];
data[0] = (byte)alertLevel;
data[1] = (byte)alertDescription;
record.Fragment = this._Cipher == null ? data : this._Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
var recordSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
var recordBytes = new byte[recordSize];
using (var stream = new MemoryStream(recordBytes))
{
record.Serialise(stream);
}
await this._Socket.SendAsync(recordBytes, timeout).ConfigureAwait(false);
}
private void SendResponseEnd(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
int size = handshakeMessage.CalculateSize(session.Version);
int maxPayloadSize = _MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
}
else
{
DTLSRecord record = CreateRecord(session, handshakeMessage, messageSequence);
session.Handshake.MessageSequence++;
DTLSRecord recordEnd = CreateRecord(session, new ServerHelloDone(), session.Handshake.MessageSequence);
session.Handshake.MessageSequence++;
int responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length + DTLSRecord.RECORD_OVERHEAD + recordEnd.Fragment.Length;
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
recordEnd.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
}
private void SendHandshakeMessage(IHandshakeMessage handshakeMessage, bool encrypt)
{
int size = handshakeMessage.CalculateSize(_Version);
int maxPayloadSize = _MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
}
else
{
DTLSRecord record = new DTLSRecord
{
RecordType = TRecordType.Handshake,
Epoch = _Epoch,
SequenceNumber = NextSequenceNumber(),
Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size]
};
if (_Version != null)
{
record.Version = _Version;
}
HandshakeRecord handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = _MessageSequence
};
_MessageSequence++;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (MemoryStream stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, _Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
_HandshakeInfo.UpdateHandshakeHash(record.Fragment);
}
int responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if ((_Cipher != null) && encrypt)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = _Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = _ServerEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
}
private void SendResponse(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
int size = handshakeMessage.CalculateSize(session.Version);
int maxPayloadSize = _MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
}
else
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.Handshake;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
record.Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size];
if (session.Version != null)
{
record.Version = session.Version;
}
HandshakeRecord handshakeRecord = new HandshakeRecord();
handshakeRecord.MessageType = handshakeMessage.MessageType;
handshakeRecord.MessageSeq = messageSequence;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (MemoryStream stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, session.Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
session.Handshake.UpdateHandshakeHash(record.Fragment);
}
int responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if (session.Cipher != null)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
}
public void Send(EndPoint remoteEndPoint, byte[] data)
{
SocketAddress address = remoteEndPoint.Serialize();
Session session = _Sessions.GetSession(address);
if (session != null)
{
try
{
DTLSRecord record = new DTLSRecord
{
RecordType = TRecordType.ApplicationData,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber()
};
if (session.Version != null)
{
record.Version = session.Version;
}
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
int responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
#if DEBUG
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
StackFrame callStack = new StackFrame(1, true);
Console.WriteLine($"Exception! Type: { ex.GetType()}\n\tData: { ex.Data.Count}\n\tMessage: { ex.Message}\n\tSource: { ex.Source}\n\t" +
$"StackTrace: { ex.StackTrace}\n\tFile: {callStack.GetFileName()}\n\t" +
$"Line: {callStack.GetFileLineNumber()}");
#else
catch
{
#endif
}
}
}
private void SendAlert(Session session, SocketAddress address, TAlertLevel alertLevel, TAlertDescription alertDescription)
{
#if DEBUG
Console.WriteLine($"Alert! {alertDescription}");
#endif
if (session != null)
{
DTLSRecord record = new DTLSRecord
{
RecordType = TRecordType.Alert,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber()
};
if (session.Version != null)
{
record.Version = session.Version;
}
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
byte[] data = new byte[2];
data[0] = (byte)alertLevel;
data[1] = (byte)alertDescription;
if (session.Cipher == null)
{
record.Fragment = data;
}
else
{
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
}
int responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
}
public void Send(EndPoint remoteEndPoint, byte[] data)
{
SocketAddress address = remoteEndPoint.Serialize();
Session session = _Sessions.GetSession(address);
if (session != null)
{
try
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.ApplicationData;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
if (session.Version != null)
{
record.Version = session.Version;
}
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
int responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
#if DEBUG
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
#else
catch
{
#endif
}
}
}
private byte[] _GetChangeCipherSpec()
{
var size = 1;
var responseSize = DTLSRecord.RECORD_OVERHEAD + size;
var response = new byte[responseSize];
var record = new DTLSRecord
{
RecordType = TRecordType.ChangeCipherSpec,
Epoch = _Epoch,
SequenceNumber = this._NextSequenceNumber(),
Fragment = new byte[size],
Version = this._Version
};
record.Fragment[0] = 1;
using (var stream = new MemoryStream(response))
{
record.Serialise(stream);
}
return(response);
}
private void SendAlert(TAlertLevel alertLevel, TAlertDescription alertDescription)
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.Alert;
record.Epoch = _Epoch;
record.SequenceNumber = NextSequenceNumber();
if (_Version != null)
{
record.Version = _Version;
}
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
byte[] data = new byte[2];
data[0] = (byte)alertLevel;
data[1] = (byte)alertDescription;
if (_Cipher == null)
{
record.Fragment = data;
}
else
{
record.Fragment = _Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
}
int responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = _ServerEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
public async Task SendAsync(byte[] data, TimeSpan timeout)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
if (this._Socket == null)
{
throw new Exception("Socket Cannot be Null");
}
if (this._Cipher == null)
{
throw new Exception("Cipher Cannot be Null");
}
var record = new DTLSRecord
{
RecordType = TRecordType.ApplicationData,
Epoch = _Epoch,
SequenceNumber = this._NextSequenceNumber(),
Version = this._Version
};
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = this._Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
var recordSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
var recordBytes = new byte[recordSize];
using (var stream = new MemoryStream(recordBytes))
{
record.Serialise(stream);
}
await this._Socket.SendAsync(recordBytes, timeout).ConfigureAwait(false);
}
private void SendChangeCipherSpec(Session session)
{
if (session == null)
{
throw new ArgumentNullException(nameof(session));
}
var size = 1;
var responseSize = DTLSRecord.RECORD_OVERHEAD + size;
var response = new byte[responseSize];
var record = new DTLSRecord
{
RecordType = TRecordType.ChangeCipherSpec,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber(),
Fragment = new byte[size]
};
record.Fragment[0] = 1;
if (session.Version != null)
{
record.Version = session.Version;
}
using (var stream = new MemoryStream(response))
{
record.Serialise(stream);
}
var parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
this._Socket.SendToAsync(parameters);
session.ChangeEpoch();
}
private IEnumerable <byte[]> _GetBytes(IHandshakeMessage handshakeMessage, bool encrypt)
{
if (handshakeMessage == null)
{
throw new ArgumentNullException(nameof(handshakeMessage));
}
var size = handshakeMessage.CalculateSize(this._Version);
var maxPayloadSize = _MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
var wholeMessage = new List <byte[]>();
var record = new DTLSRecord
{
RecordType = TRecordType.Handshake,
Epoch = _Epoch,
Version = this._Version
};
var handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = _MessageSequence
};
if (!(handshakeMessage.MessageType == THandshakeType.HelloVerifyRequest ||
(handshakeMessage.MessageType == THandshakeType.ClientHello && (handshakeMessage as ClientHello).Cookie == null)))
{
record.Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size];
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
handshakeRecord.FragmentOffset = 0u;
using (var stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, this._Version);
}
this._HandshakeInfo.UpdateHandshakeHash(record.Fragment);
}
var dataMessage = new byte[size];
using (var stream = new MemoryStream(dataMessage))
{
handshakeMessage.Serialise(stream, this._Version);
}
var dataMessageFragments = dataMessage.ChunkBySize(maxPayloadSize);
handshakeRecord.FragmentOffset = 0U;
dataMessageFragments.ForEach(x =>
{
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)x.Count();
record.SequenceNumber = this._NextSequenceNumber();
var baseMessage = new byte[HandshakeRecord.RECORD_OVERHEAD];
using (var stream = new MemoryStream(baseMessage))
{
handshakeRecord.Serialise(stream);
}
record.Fragment = baseMessage.Concat(x).ToArray();
var responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + x.Count();
if ((this._Cipher != null) && encrypt)
{
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = this._Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
var response = new byte[responseSize];
using (var stream = new MemoryStream(response))
{
record.Serialise(stream);
}
wholeMessage.Add(response);
handshakeRecord.FragmentOffset += (uint)x.Count();
});
this._MessageSequence++;
return(wholeMessage);
}
else
{
var record = new DTLSRecord
{
RecordType = TRecordType.Handshake,
Epoch = _Epoch,
SequenceNumber = this._NextSequenceNumber(),
Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size],
Version = this._Version
};
var handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = _MessageSequence
};
this._MessageSequence++;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (var stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, this._Version);
}
if (!(handshakeMessage.MessageType == THandshakeType.HelloVerifyRequest ||
(handshakeMessage.MessageType == THandshakeType.ClientHello && (handshakeMessage as ClientHello).Cookie == null)))
{
this._HandshakeInfo.UpdateHandshakeHash(record.Fragment);
}
var responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if ((this._Cipher != null) && encrypt)
{
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = this._Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
var response = new byte[responseSize];
using (var stream = new MemoryStream(response))
{
record.Serialise(stream);
}
return(new List <byte[]>()
{
response
});
}
}
private void SendChangeCipherSpec(Session session)
{
int size = 1;
int responseSize = DTLSRecord.RECORD_OVERHEAD + size;
byte[] response = new byte[responseSize];
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.ChangeCipherSpec;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
record.Fragment = new byte[size];
record.Fragment[0] = 1;
if (session.Version != null)
record.Version = session.Version;
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
session.ChangeEpoch();
}
private void SendAlert(TAlertLevel alertLevel, TAlertDescription alertDescription)
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.Alert;
record.Epoch = _Epoch;
record.SequenceNumber = NextSequenceNumber();
if (_Version != null)
record.Version = _Version;
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
byte[] data = new byte[2];
data[0] = (byte)alertLevel;
data[1] = (byte)alertDescription;
if (_Cipher == null)
record.Fragment = data;
else
record.Fragment = _Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
int responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = _ServerEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
public void Send(byte[] data)
{
try
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.ApplicationData;
record.Epoch = _Epoch;
record.SequenceNumber = NextSequenceNumber();
if (_Version != null)
record.Version = _Version;
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = _Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.ApplicationData, data, 0, data.Length);
int responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = _ServerEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
if (_Socket != null)
_Socket.SendToAsync(parameters);
}
#if DEBUG
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
#else
catch
{
#endif
}
}
private void SendResponse(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
int size = handshakeMessage.CalculateSize(session.Version);
int maxPayloadSize = _MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
}
else
{
DTLSRecord record = new DTLSRecord();
record.RecordType = TRecordType.Handshake;
record.Epoch = session.Epoch;
record.SequenceNumber = session.NextSequenceNumber();
record.Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size];
if (session.Version != null)
record.Version = session.Version;
HandshakeRecord handshakeRecord = new HandshakeRecord();
handshakeRecord.MessageType = handshakeMessage.MessageType;
handshakeRecord.MessageSeq = messageSequence;
handshakeRecord.Length = (uint)size;
handshakeRecord.FragmentLength = (uint)size;
using (MemoryStream stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, session.Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
session.Handshake.UpdateHandshakeHash(record.Fragment);
}
int responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if (session.Cipher != null)
{
long sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
byte[] response = new byte[responseSize];
using (MemoryStream stream = new MemoryStream(response))
{
record.Serialise(stream);
}
SocketAsyncEventArgs parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
_Socket.SendToAsync(parameters);
}
}
private void SendResponse(Session session, IHandshakeMessage handshakeMessage, ushort messageSequence)
{
if (session == null)
{
throw new ArgumentNullException(nameof(session));
}
if (handshakeMessage == null)
{
throw new ArgumentNullException(nameof(handshakeMessage));
}
var size = handshakeMessage.CalculateSize(session.Version);
var maxPayloadSize = this._MaxPacketSize - DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD;
if (size > maxPayloadSize)
{
//fragments
return;
}
var record = new DTLSRecord
{
RecordType = TRecordType.Handshake,
Epoch = session.Epoch,
SequenceNumber = session.NextSequenceNumber(),
Fragment = new byte[HandshakeRecord.RECORD_OVERHEAD + size]
};
if (session.Version != null)
{
record.Version = session.Version;
}
var handshakeRecord = new HandshakeRecord
{
MessageType = handshakeMessage.MessageType,
MessageSeq = messageSequence,
Length = (uint)size,
FragmentLength = (uint)size
};
using (var stream = new MemoryStream(record.Fragment))
{
handshakeRecord.Serialise(stream);
handshakeMessage.Serialise(stream, session.Version);
}
if (handshakeMessage.MessageType != THandshakeType.HelloVerifyRequest)
{
session.Handshake.UpdateHandshakeHash(record.Fragment);
}
var responseSize = DTLSRecord.RECORD_OVERHEAD + HandshakeRecord.RECORD_OVERHEAD + size;
if (session.Cipher != null)
{
var sequenceNumber = ((long)record.Epoch << 48) + record.SequenceNumber;
record.Fragment = session.Cipher.EncodePlaintext(sequenceNumber, (byte)TRecordType.Handshake, record.Fragment, 0, record.Fragment.Length);
responseSize = DTLSRecord.RECORD_OVERHEAD + record.Fragment.Length;
}
var response = new byte[responseSize];
using (var stream = new MemoryStream(response))
{
record.Serialise(stream);
}
var parameters = new SocketAsyncEventArgs()
{
RemoteEndPoint = session.RemoteEndPoint
};
parameters.SetBuffer(response, 0, responseSize);
this._Socket.SendToAsync(parameters);
}