protected void StartTopicMonitoring()
{
lock (_lock)
{
if (!this._isActivated)
{
var taskFactory = new TaskFactory(_cancellationTokenSource.Token);
this._isActivated = true;
var cancellationToken = _cancellationTokenSource.Token;
_task = taskFactory.StartNew(async(_) =>
{
_sharedSymKeyId = await _whisperRpc.RegisterSymKeyAsync(_sharedKey);
string messageFilter = await _whisperRpc.CreateMessageFilterAsync(topicHex: _sessionTopic, symKeyId: _sharedSymKeyId);
var messageHandlerResolver = _messageHandlerResolverBuilder.Build();
this._producerConsumerQueue = new ProducerConsumerQueue(messageHandlerResolver, cancellationToken);
do
{
var messages = await _transportClient.GetSessionMessagesAsync(messageFilter);
if (messages != null &&
messages.Count != 0)
{
foreach (var message in messages)
{
if (!_signService.VerifySign(message.Payload, message.Signature,
_counterPartyPubSigningKey))
{
continue;
}
_producerConsumerQueue.Enqueue(message.Message);
}
continue;
}
//Poll whisper each 5 sec for new messages
await Task.Delay(5000, cancellationToken);
} while (!cancellationToken.IsCancellationRequested);
}, cancellationToken, TaskCreationOptions.LongRunning);
}
else
{
throw new Exception("Session was already started");
}
}
}
/// <summary>
/// Run listener which would process incoming messages.
/// </summary>
/// <param name="messageHandler">Handler which authorizes originator's Vasp and processes Transfer Request and Transfer Dispatch Messages</param>
public void RunListener(IVaspMessageHandler messageHandler)
{
lock (_lock)
{
if (!_hasStartedListening)
{
_hasStartedListening = true;
var token = _cancellationTokenSource.Token;
var taskFactory = new TaskFactory(_cancellationTokenSource.Token);
this._listener = taskFactory.StartNew(async(_) =>
{
var privateKeyId = await _whisperRpc.RegisterKeyPairAsync(this._handshakeKey.PrivateKey);
string messageFilter =
await _whisperRpc.CreateMessageFilterAsync(topicHex: _vaspContractInfo.VaspCode.Code,
privateKeyId);
do
{
var sessionRequestMessages = await _transportClient.GetSessionMessagesAsync(messageFilter);
if (sessionRequestMessages != null &&
sessionRequestMessages.Count != 0)
{
foreach (var message in sessionRequestMessages)
{
var sessionRequestMessage = message.Message as SessionRequestMessage;
if (sessionRequestMessage == null)
{
continue;
}
var isAuthorized =
await messageHandler.AuthorizeSessionRequestAsync(sessionRequestMessage.VASP);
if (!isAuthorized)
{
continue;
}
var originatorVaspContractInfo =
await _ethereumRpc.GetVaspContractInfoAync(sessionRequestMessage.VASP
.VaspIdentity);
if (!_signService.VerifySign(message.Payload, message.Signature,
originatorVaspContractInfo.SigningKey))
{
continue;
}
var sharedSecret =
this._handshakeKey.GenerateSharedSecretHex(sessionRequestMessage.HandShake
.EcdhPubKey);
var session = new BeneficiarySession(
originatorVaspContractInfo,
this.VaspInfo,
sessionRequestMessage.Message.SessionId,
sessionRequestMessage.HandShake.TopicA,
originatorVaspContractInfo.SigningKey,
sharedSecret,
this._signatureKey,
this._whisperRpc,
messageHandler,
_transportClient,
_signService);
this.NotifySessionCreated(session);
session.OnSessionTermination += this.ProcessSessionTermination;
if (_beneficiarySessionsDict.TryAdd(session.SessionId, session))
{
await session.StartAsync();
}
else
{
await session.TerminateAsync(TerminationMessage.TerminationMessageCode
.SessionClosedTransferDeclinedByBeneficiaryVasp);
}
}
continue;
}
await Task.Delay(5000, token);
} while (!token.IsCancellationRequested);
}, token, TaskCreationOptions.LongRunning);
}
else
{
throw new Exception("You can start observation only once.");
}
}
}