/// <summary>
/// Creates a new wire message.
/// </summary>
/// <param name="messageType">Message type name</param>
/// <param name="serializedMessage">Serialized message</param>
/// <param name="serializer">Serializer used to serialize the signed content</param>
/// <param name="keyPair">RSA key pair to be used for creating a RSA signature for the message data</param>
/// <param name="sharedSecret">Shared secret (wire message will be not encrypted, if null)</param>
/// <param name="error">Species whether the wire message is in error state</param>
/// <param name="uniqueCallKey">Unique key to correlate RPC call</param>
/// <returns>The created wire message</returns>
/// <exception cref="ArgumentException">Thrown if the message type is left empty.</exception>
public WireMessage CreateWireMessage(
string messageType,
byte[] serializedMessage,
ISerializerAdapter serializer,
RsaKeyPair keyPair = null,
byte[] sharedSecret = null,
bool error = false,
byte[] uniqueCallKey = null)
{
if (string.IsNullOrWhiteSpace(messageType))
{
throw new ArgumentException("Message type must not be empty.", nameof(messageType));
}
byte[] iv =
sharedSecret == null
? new byte[0]
: AesEncryption.GenerateIv();
byte[] rawContent;
if (keyPair != null && sharedSecret != null)
{
var signedMessageData =
new SignedMessageData()
{
MessageRawData = serializedMessage,
Signature =
RsaSignature.CreateSignature(
keySize: keyPair.KeySize,
sendersPrivateKeyBlob: keyPair.PrivateKey,
rawData: serializedMessage)
};
rawContent = serializer.Serialize(typeof(SignedMessageData), signedMessageData);
}
else
{
rawContent = serializedMessage;
}
byte[] messageContent =
sharedSecret == null
? rawContent
: AesEncryption.Encrypt(
dataToEncrypt: rawContent,
sharedSecret: sharedSecret,
iv: iv);
return
(new WireMessage()
{
MessageType = messageType,
Data = messageContent,
Iv = iv,
Error = error,
UniqueCallKey = uniqueCallKey
});
}
/// <summary>
/// Creates a new instance of the RemotingSession class.
/// </summary>
/// <param name="keySize">Key size of the RSA keys for asymmetric encryption</param>
/// <param name="clientPublicKey">Public key of this session's client</param>
/// <param name="server">Server instance, that hosts this session</param>
/// <param name="rawMessageTransport">Component, that does the raw message transport (send and receive)</param>
internal RemotingSession(int keySize, byte[] clientPublicKey, IRemotingServer server,
IRawMessageTransport rawMessageTransport)
{
_sessionId = Guid.NewGuid();
_lastActivityTimestamp = DateTime.Now;
_isAuthenticated = false;
_keyPair = new RsaKeyPair(keySize);
CreatedOn = DateTime.Now;
_remoteDelegateInvocationEventAggregator = new RemoteDelegateInvocationEventAggregator();
_server = server ?? throw new ArgumentNullException(nameof(server));
_delegateProxyFactory = _server.ServiceRegistry.GetService <IDelegateProxyFactory>();
_delegateProxyCache = new ConcurrentDictionary <Guid, IDelegateProxy>();
_rawMessageTransport = rawMessageTransport ?? throw new ArgumentNullException(nameof(rawMessageTransport));
_clientPublicKeyBlob = clientPublicKey;
_rawMessageTransport.ReceiveMessage += OnReceiveMessage;
_rawMessageTransport.ErrorOccured += OnErrorOccured;
MessageEncryption = clientPublicKey != null;
WireMessage completeHandshakeMessage;
if (MessageEncryption)
{
var encryptedSessionId =
RsaKeyExchange.EncryptSecret(
keySize: _server.SessionRepository.KeySize,
receiversPublicKeyBlob: clientPublicKey,
secretToEncrypt: _sessionId.ToByteArray(),
sendersPublicKeyBlob: _keyPair.PublicKey);
var rawContent = _server.Serializer.Serialize(encryptedSessionId);
var signedMessageData =
new SignedMessageData()
{
MessageRawData = rawContent,
Signature =
RsaSignature.CreateSignature(
keySize: keySize,
sendersPrivateKeyBlob: _keyPair.PrivateKey,
rawData: rawContent)
};
var rawData = _server.Serializer.Serialize(typeof(SignedMessageData), signedMessageData);
completeHandshakeMessage =
new WireMessage
{
MessageType = "complete_handshake",
Data = rawData
};
}
else
{
completeHandshakeMessage =
new WireMessage
{
MessageType = "complete_handshake",
Data = _sessionId.ToByteArray()
};
}
_remoteDelegateInvocationEventAggregator.RemoteDelegateInvocationNeeded +=
(delegateType, uniqueCallKey, handlerKey, arguments) =>
{
var sharedSecret =
MessageEncryption
? _sessionId.ToByteArray()
: null;
var remoteDelegateInvocationMessage =
new RemoteDelegateInvocationMessage
{
UniqueCallKey = uniqueCallKey,
HandlerKey = handlerKey,
DelegateArguments = arguments
};
var remoteDelegateInvocationWebsocketMessage =
_server.MessageEncryptionManager
.CreateWireMessage(
serializedMessage: _server.Serializer.Serialize(remoteDelegateInvocationMessage),
serializer: _server.Serializer,
sharedSecret: sharedSecret,
keyPair: _keyPair,
messageType: "invoke");
// Invoke remote delegate on client
_rawMessageTransport.SendMessage(
_server.Serializer.Serialize(remoteDelegateInvocationWebsocketMessage));
return(null);
};
_rawMessageTransport.SendMessage(_server.Serializer.Serialize(completeHandshakeMessage));
}
