private string _tempPath = ""; // temp file path
#endregion Fields
#region Constructors
public DtmFileTransfer(ICipherMode Cipher, long FileId = 0, int BufferCount = 1024, int BufferSize = 262144)
{
_fileSymProcessor = Cipher;
_fileId = FileId;
_rcvBuffer = new PacketBuffer(BufferCount);
_sndBuffer = new PacketBuffer(BufferCount);
_bufferSize = BufferSize;
_bufferCount = BufferCount;
}
/// <summary>
/// Disconnect from the remote host and teardown the connection
/// </summary>
public void Disconnect()
{
_isEstablished = false;
_isDisconnecting = true;
// stop sending keepalives
StopPulse();
try
{
if (_clientSocket.IsConnected)
{
Transmit(DtmPacketTypes.Service, (short)DtmServiceFlags.Terminate, 0, null, true);
_clientSocket.TcpStream.Flush();
_clientSocket.Close();
}
}
catch { }
try
{
if (_clientSocket != null)
{
_clientSocket.Dispose();
_clientSocket = null;
}
if (_evtSendWait != null)
{
_evtSendWait.Dispose();
_evtSendWait = null;
}
if (_rcvBuffer != null)
{
_rcvBuffer.Dispose();
_rcvBuffer = null;
}
if (_sndBuffer != null)
{
_sndBuffer.Dispose();
_sndBuffer = null;
}
}
catch { }
try
{
TearDown();
}
catch (Exception ex)
{
if (SessionError != null)
SessionError(this, new DtmErrorEventArgs(new CryptoProcessingException("DtmKex:Disconnect", "The tear down operation experienced an error!", ex), DtmErrorSeverity.Warning));
}
finally
{
if (Disconnected != null)
Disconnected(this);
}
}
/// <summary>
/// Initialize this class with a random generator
/// </summary>
///
/// <param name="Parameters">A populated <see cref="DtmParameters"/> class containing the session parameters</param>
/// <param name="Host">A populated <see cref="DtmClient"/> class containing the servers identity data</param>
/// <param name="Generator">The initialized <see cref="IRandom"/> Prng instance</param>
/// <param name="BufferCount">The number of send/receive buffers, default is 1024</param>
/// <param name="DisposeEngines">if set to true (default), the primary symmetric ciphers are disposed when this class is disposed</param>
public DtmKex(DtmParameters Parameters, DtmClient Host, IRandom Generator, int BufferCount = 1024, bool DisposeEngines = true)
{
_disposeEngines = DisposeEngines;
_dtmParameters = Parameters;
_dtmHost = Host;
_srvIdentity = new DtmIdentity(Host.PublicId, Parameters.AuthPkeId, Parameters.AuthSession, 0);
_exchangeState = DtmExchangeFlags.Connect;
_rcvBuffer = new PacketBuffer(BufferCount);
_sndBuffer = new PacketBuffer(BufferCount);
_rndGenerator = Generator;
_bufferCount = BufferCount;
}
/// <summary>
/// Processes and queues incoming packets
/// </summary>
private void ProcessAndPush(PacketBuffer Buffer, MemoryStream PacketStream)
{
int hdrLen = DtmPacket.GetHeaderSize();
int pktLen = 0;
// process the whole packet
PacketStream.Seek(0, SeekOrigin.Begin);
// get the header
DtmPacket dtmPkt = new DtmPacket(PacketStream);
PacketStream.Seek(0, SeekOrigin.Begin);
// track high sequence number, filters corrupt packets
if (dtmPkt.Sequence > _seqCounter && dtmPkt.PayloadLength < MAXRCVBUFFER && dtmPkt.OptionFlag < 1000)
_seqCounter = dtmPkt.Sequence;
// out of sync, possible packet loss
if (_seqCounter - _rcvSequence > ResendThreshold)
{
// request a retransmission
Transmit(DtmPacketTypes.Service, (short)DtmServiceFlags.Resend, _rcvSequence + 1);
}
if (dtmPkt.PayloadLength + hdrLen == PacketStream.Length)
{
// resend was already processed
if (dtmPkt.Sequence < _rcvSequence)
return;
// push onto buffer
Buffer.Push(dtmPkt.Sequence, PacketStream);
}
// more than one packet
else if (dtmPkt.PayloadLength + hdrLen < PacketStream.Length)
{
byte[] buffer;
long pos = 0;
do
{
// get packet position and size
pos = PacketStream.Position;
if (PacketStream.Length - pos < DtmPacket.GetHeaderSize())
{
// next packet corrupted, request a retransmission and exit
Transmit(DtmPacketTypes.Service, (short)DtmServiceFlags.Resend, Buffer.GetHighKey() + 1);
return;
}
dtmPkt = new DtmPacket(PacketStream);
pktLen = (int)(hdrLen + dtmPkt.PayloadLength);
if (pktLen > MAXRCVBUFFER || pktLen < 0 || PacketStream.Length - pos < pktLen)
{
// packet corrupted, request a retransmission and exit
Transmit(DtmPacketTypes.Service, (short)DtmServiceFlags.Resend, Buffer.GetHighKey() + 1);
return;
}
else
{
// create the buffer
buffer = new byte[pktLen];
PacketStream.Seek(pos, SeekOrigin.Begin);
PacketStream.Read(buffer, 0, (int)pktLen);
// push onto buffer
Buffer.Push(dtmPkt.Sequence, new MemoryStream(buffer));
}
} while (PacketStream.Position < PacketStream.Length);
}
// malformed packet, send retransmit request
else if (dtmPkt.PayloadLength > MAXRCVBUFFER || dtmPkt.PayloadLength < 0 || dtmPkt.PayloadLength + hdrLen > PacketStream.Length)
{
// packet corrupted, request a retransmission of last in queue + 1
Transmit(DtmPacketTypes.Service, (short)DtmServiceFlags.Resend, Buffer.GetHighKey() + 1);
}
}
