private async void CompleteFriendshipNFC(Windows.Networking.Proximity.ProximityDevice sender, Windows.Networking.Proximity.ProximityMessage message)
{
// Stop subscribing to the message. This means the other user finished sending a friend request
AppServices.myProximityDevice.StopSubscribingForMessage(this.subscribedMessageID);
this.subscribedMessageID = -1;
// Stop publishing friend request sent message as the user has already processed it
AppServices.myProximityDevice.StopPublishingMessage(this.publishedMessageID);
this.publishedMessageID = -1;
// Other user accepted our friend request successfully so we add them to our list and save the encryption key
if (message.DataAsString.Equals("true"))
{
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
AppServices.friendsData.friendsList.Add(new Tap_Chat.ViewModel.FriendsListEntry()
{
encryptedUsername = this.nfcFriendName, isOnline = true, encryptionKey = AppServices.encryptionAlgorithim.CreateSymmetricKey(keyBuff)
});
this.EndAsyncOperationsSuccess();
this.PrintMessage("Added Friend Successfully!");
});
}
// Other user failed to accept our friend request so we print out a message and end
else
{
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
// Even though the add failed we call success to remove the progress indicator and enable input
this.EndAsyncOperationsSuccess();
this.PrintMessage("Other user had an error. Add friend failed");
});
}
}
private async void AcceptFriendRequestNFC(Windows.Networking.Proximity.ProximityDevice sender, Windows.Networking.Proximity.ProximityMessage message)
{
// Stop subscribing to the message. This means the other user finished sending a friend request
AppServices.myProximityDevice.StopSubscribingForMessage(this.subscribedMessageID);
this.subscribedMessageID = -1;
// Other user successfully sent friend request (message is not "false"), so we receive the generated encryption key
if (message.DataAsString.Equals("false") == false)
{
// Accept the friend request
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
this.StartAsyncOperations("Accepting friend request...");
});
AppServices.operationComplete = false;
AppServices.buddyService.AcceptFriendRequest(AppServices.localUsernameEncrypted, this.nfcFriendName, new AcceptRequestCallback());
//await Task.Run(() =>
//{
while (AppServices.operationComplete == false)
{
;
}
//});
// Unable to accept friend request. Error out and tell the other user
if (AppServices.operationSuccessful == false)
{
this.publishedMessageID = AppServices.myProximityDevice.PublishMessage(this.friendRequestCompleteNFCMessageType, "false");
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
this.EndAsyncOperationsError();
});
return;
}
// Accepted friend request successfully. Tell the other user and add them to our friends list
this.publishedMessageID = AppServices.myProximityDevice.PublishMessage(this.friendRequestCompleteNFCMessageType, "true");
this.newEncryptionKey = message.DataAsString;
IBuffer keyBuff = CryptographicBuffer.DecodeFromHexString(this.newEncryptionKey);
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
AppServices.friendsData.friendsList.Add(new Tap_Chat.ViewModel.FriendsListEntry()
{
encryptedUsername = this.nfcFriendName, isOnline = true, encryptionKey = AppServices.encryptionAlgorithim.CreateSymmetricKey(keyBuff)
});
this.EndAsyncOperationsSuccess();
this.PrintMessage("Added Friend Successfully!");
});
}
// Other user had an issue sending a request so we print a message and end
else
{
// We ended in success but the other user had an error so we hide the progress indicator and print a different message
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
this.EndAsyncOperationsSuccess();
});
this.PrintMessageAsync("Other user had an error. Unable to add friend.");
return;
}
}
private async void ReceiveUsernameNFC(Windows.Networking.Proximity.ProximityDevice device, Windows.Networking.Proximity.ProximityMessage message)
{
// Once a message is received stop subscribing for it
AppServices.myProximityDevice.StopSubscribingForMessage(this.subscribedMessageID);
this.subscribedMessageID = -1;
// Check to see who's username is greater. The one with the greater username sends the request and generates a key
int compareResult = string.Compare(AppServices.localUsernameEncrypted, message.DataAsString);
this.nfcFriendName = message.DataAsString;
// I must send friend request using the App42 API
if (compareResult > 0)
{
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
this.StartAsyncOperations("Establishing friendship...");
});
AppServices.operationComplete = false;
AppServices.buddyService.SendFriendRequest(AppServices.localUsernameEncrypted, message.DataAsString, "Friend Request", new FriendRequestCallback());
//await Task.Run(() =>
//{
while (AppServices.operationComplete == false)
{
;
}
//});
// Once the friend request is sent completely we stop publishing our name
AppServices.myProximityDevice.StopPublishingMessage(this.publishedMessageID);
this.publishedMessageID = -1;
// If sending the request failed we notify the other user
if (AppServices.operationSuccessful == false)
{
this.publishedMessageID = AppServices.myProximityDevice.PublishMessage(this.friendRequestSentNFCMessageType, "false");
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
this.EndAsyncOperationsError();
});
return;
}
// The send was successful so we tell the other user our encryption key and now wait for them to accept and notify us
keyBuff = CryptographicBuffer.GenerateRandom(256);
this.newEncryptionKey = CryptographicBuffer.EncodeToHexString(keyBuff);
this.publishedMessageID = AppServices.myProximityDevice.PublishMessage(this.friendRequestSentNFCMessageType, this.newEncryptionKey);
this.subscribedMessageID = AppServices.myProximityDevice.SubscribeForMessage(this.friendRequestCompleteNFCMessageType, CompleteFriendshipNFC);
}
// I must wait for a friend request from the other user using the App42 API
else
{
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
this.StartAsyncOperations("Waiting for friendship data...");
});
this.subscribedMessageID = AppServices.myProximityDevice.SubscribeForMessage(this.friendRequestSentNFCMessageType, AcceptFriendRequestNFC);
AppServices.myProximityDevice.StopPublishingMessage(this.publishedMessageID);
this.publishedMessageID = -1;
}
}
private void messageReceived(
Windows.Networking.Proximity.ProximityDevice device,
Windows.Networking.Proximity.ProximityMessage message)
{
MessageBlock.Text += "Message received: " + message.DataAsString + "\n";
}
private void messageReceived(Windows.Networking.Proximity.ProximityDevice device,
Windows.Networking.Proximity.ProximityMessage message)
{
WriteMessageText("Message received: " + message.DataAsString + "\n");
}
private void ReceiveEncryptionKey(Windows.Networking.Proximity.ProximityDevice sender, Windows.Networking.Proximity.ProximityMessage message)
{
string keyString = message.DataAsString;
this.keyBuff = CryptographicBuffer.DecodeFromHexString(keyString);
lastSelected.encryptionKey = AppServices.encryptionAlgorithim.CreateSymmetricKey(this.keyBuff);
this.PrintMessageAsync("Secure connection established! You may now separate your devices.");
}
