public static void Stop()
{
if(echoListener != null) echoListener.Close();
if(echoResponder != null) echoResponder.Close();
echoResponder = null;
echoListener = null;
}
private async static void requestReceived(TCPSocket sender)
{
await uiThreadDispatcher.RunAsync(CoreDispatcherPriority.Normal, async () =>
{
try
{
progressIndeterminate();
sender.ProgressRepport += (x) => { if (ProgressRepport != null) ProgressRepport(x); };
string requestContents = await sender.Recv();
progressStop();
Request receivedRequest = JSONHandling.ParseJSONResponse<Request>(requestContents);
await requestHandlerMap[receivedRequest.Type](receivedRequest.SenderGuid, receivedRequest.Data, sender);
}
catch(OutOfMemoryException)
{
DialogBoxes.ShowMessageBox("File too big to fit in memory");
}
catch(FileTransferException error)
{
DialogBoxes.ShowMessageBox(error.Message);
}
catch(Exception error)
{
DialogBoxes.ShowMessageBox("Unknown error " + error.Message);
}
finally
{
progressStop();
sender.Send(Strings.RESPONSE_REJECT);
}
});
}
public async static Task Reboot()
{
if (listenerSocket != null) listenerSocket.Close();
listenerSocket = null;
MulticastDiscovery.Stop();
await Init(myName);
}
private async static void discoveryRequestReceived(Windows.Networking.Sockets.DatagramSocketMessageReceivedEventArgs args)
{
if (args.RemoteAddress.RawName == "127.0.0.1") return;
try
{
var responseSocket = new TCPSocket();
await responseSocket.Connect(args.RemoteAddress.RawName, DEFAULT_DISCOVERY_PORT);
await responseSocket.Send(await GuidHandling.GetMyGuid() + ":" + myName);
}
catch(Exception)
{
}
}
private static async void deviceDiscovered(TCPSocket sender)
{
try
{
string ip = sender.GetIP();
string receivedString = await sender.Recv();
if (receivedString.IndexOf(":") == -1 || receivedString.IndexOf(":") == receivedString.Length-1) return;
string guid = receivedString.Substring(0, receivedString.IndexOf(":"));
if (guid == (await GuidHandling.GetMyGuid())) return;
string name = receivedString.Substring(receivedString.IndexOf(":") + 1);
DeviceDiscovered(ip, guid, name);
}
catch(Exception)
{
}
}
public async static Task Init(string name)
{
if (uiThreadDispatcher == null) uiThreadDispatcher = Windows.UI.Core.CoreWindow.GetForCurrentThread().Dispatcher;
myName = name;
Peers = new ObservableCollection<Peer>();
preSendRegistrations = new Dictionary<string, PreSendRequest>();
preSendRegistrationsNoCrypt = new Dictionary<string, PreSendRequestNoCrypt>();
listenerSocket = new TCPSocket();
listenerSocket.ConnectionReceived += requestReceived;
initializeHandlerMap();
await listenerSocket.StartListening("32102");
if(!(await DataStorage.GetStoredItemAsync("Peers")==null))
{
Peer[] newPeers = JSONHandling.ParseJSONResponse<Peer[]>(await DataStorage.GetStoredItemAsync("Peers"));
for(int i=0;i<newPeers.Length;i++) Peers.Add(newPeers[i]);
}
RefreshPeerMap();
await MulticastDiscovery.StartMulticastResponder(myName);
MulticastDiscovery.DeviceDiscovered += newPeerDiscovered;
}
private async static Task runDiscoveryServer()
{
echoListener = new TCPSocket();
echoListener.ConnectionReceived += deviceDiscovered;
await echoListener.StartListening(DEFAULT_DISCOVERY_PORT);
}
private async static Task<TCPSocket> sendRequestToPeer(string peer, string type, string data, bool repportProgress=false, int timeout=5000)
{
var newSocket = new TCPSocket();
await newSocket.Connect(peerMap[peer].LastKnownIP, "32102");
if (repportProgress) newSocket.ProgressRepport += progressRepport;
return await sendRequestToSocket(newSocket, type, data, timeout);
}
private async static Task preSendNoCryptRequestReceived(string peer, string data, TCPSocket socket)
{
if (peerMap.ContainsKey(peer) && peerMap[peer].Paired)
{
PreSendRequestNoCrypt registration = JSONHandling.ParseJSONResponse<PreSendRequestNoCrypt>(data);
await DialogBoxes.AskForConfirmation(registration.FileName + " from " + peerMap[peer].Name + " over insecure connection. Accept?", async () =>
{
preSendRegistrationsNoCrypt[peer] = registration;
await socket.Send(Strings.RESPONSE_OK);
}, async () =>
{
await socket.Send(Strings.RESPONSE_REJECT);
});
}
else
{
await socket.Send(Strings.RESPONSE_NOT_PAIRED);
}
}
private async static Task preSendRequestReceived(string peer, string data, TCPSocket socket)
{
if(peerMap.ContainsKey(peer) && peerMap[peer].Paired)
{
PreSendRequest registration = JSONHandling.ParseJSONResponse<PreSendRequest>(data);
if(!registration.key.VerifySignature(peerMap[peer].SharedPassword))
{
socket.Send(Strings.RESPONSE_REJECT);
}
await DialogBoxes.AskForConfirmation(registration.FileName+" from "+peerMap[peer].Name+". Accept?", async () =>
{
preSendRegistrations[peer] = registration;
await socket.Send(Strings.RESPONSE_OK);
}, async () =>
{
await socket.Send(Strings.RESPONSE_REJECT);
});
}
else
{
await socket.Send(Strings.RESPONSE_NOT_PAIRED);
}
}
private async static Task fileReceivedNoCrypt(string peer, string data, TCPSocket socket)
{
progressIndeterminate();
if (!(peerMap.ContainsKey(peer) && peerMap[peer].Paired))
{
progressStop();
await socket.Send(Strings.RESPONSE_NOT_PAIRED);
return;
}
if (!(preSendRegistrationsNoCrypt.ContainsKey(peer)))
{
progressStop();
await socket.Send(Strings.RESPONSE_REJECT);
return;
}
PreSendRequestNoCrypt registration = preSendRegistrationsNoCrypt[peer];
preSendRegistrationsNoCrypt.Remove(peer);
File receivedFile = JSONHandling.ParseJSONResponse<File>(data);
if (receivedFile.FileName != registration.FileName)
{
progressStop();
throw new FileTransferException("File name mismatch");
}
byte[] fileContents = receivedFile.GetContents();
progressStop();
FileReceived(receivedFile.FileName, fileContents);
}
private async static Task pairRequestReceived(string peer, string data, TCPSocket socket)
{
progressIndeterminate();
var request = JSONHandling.ParseJSONResponse<PairingRequest>(data);
if(request.Guid!=peer)
{
progressStop();
await socket.Send(Strings.RESPONSE_REJECT);
return;
}
string signatureSecret = await DialogBoxes.AskForInput("Pairing request", "Please enter the shared password");
if (signatureSecret == null)
{
progressStop();
await socket.Send(Strings.RESPONSE_REJECT);
return;
}
if(!request.PublicKey.VerifySignature(signatureSecret))
{
progressStop();
await socket.Send(Strings.RESPONSE_BAD_SIGNATURE);
await DialogBoxes.ShowMessageBox("Shared password incorrect");
return;
}
string myPrivateKey = DiffieHellman.generate_DH_Private();
string myPublicKey = DiffieHellman.calculate_DH_Public(myPrivateKey);
PublicKey returnedKey = new PublicKey(myPublicKey, signatureSecret);
await sendRequestToSocket(socket, Strings.REQYEST_TYPE_PUBLICKEY, JSONHandling.SerializeObject(returnedKey));
string response = await socket.Recv();
progressStop();
if(response!=Strings.RESPONSE_OK)
{
await DialogBoxes.ShowMessageBox(response);
return;
}
Peer newPeer = new Peer(request.Guid, request.Name);
newPeer.LastKnownIP = socket.GetIP();
newPeer.MyPrivateKey = myPrivateKey;
newPeer.PublicKey = request.PublicKey.Key;
newPeer.SharedPassword = signatureSecret;
addPeer(newPeer);
await StorePeers();
RefreshPeerMap();
}
private async static Task<TCPSocket> sendRequestToSocket(TCPSocket socket, string type, string data, int timeout=5000)
{
var request = new Request();
request.Data = data;
request.SenderGuid = await GuidHandling.GetMyGuid();
request.Type = type;
socket.SetTimeout(timeout);
await socket.Send(JSONHandling.SerializeObject(request));
return socket;
}
