WSServer Component

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The WSServer component is used to create a WebSocket server.

Syntax

nsoftware.IPWorksSSL.Wsserver

Remarks

The WSServer component functions as a server that facilitates incoming WebSocket connections and offers a convenient means of transmitting and receiving data over the established connections.

To start, the LocalPort property must be specified to a valid port. This port will be used to accept incoming connections. Then, call the StartListening method to start listening on the specified port. The WSServer component supports both plaintext and Secure Sockets Layer/Transport Layer Security (SSL/TLS) connections. The SSLStatus event provides information about the SSL handshake. Additional SSL related settings are also supported via the Config method. The SSLCert properties are used to select a certificate for the server. Note: A valid certificate MUST be selected before the server can function.

Upon a client's connection, the WebSocketOpenRequest event will be fired. To accept the connection, simply allow the event to complete its execution. Conversely, to reject the request, the StatusCode parameter can be set to an appropriate HTTP error code, such as 401.

By default, each instance of WSServer has the capacity to handle up to 1,000 simultaneous incoming connections. You can change the maximum number of simultaneous connections by adjusting the MaxConnections configuration setting. This setting allows you to increase the limit up to 100,000 or decrease it to a lower value based on your needs.

Each connection is identified by a unique ConnectionId, an identifier generated by the component to distinguish individual connections. The ConnectionId is also included as a parameter in WSServer's events to identify the associated connection.

After receiving a connection, incoming data can be accessed through the DataIn event. To transmit data to a client, the Send, SendText, or SendFile methods can be employed, or the DataToSend field can be set accordingly.

Threading in Server Applications

In .NET, all socket-based components perform all Socket.IO through asynchronous methods. Each call consumes a thread from the system's thread pool, and thus the number of concurrent calls is limited to the number of worker threads returned by System.Threading.ThreadPool.GetMaxThreads. When using several components that can each create a socket connection or a single component that can create multiple socket connections, the application may enter a state in which all of the pool threads are in use for receiving. In a scenario such as this, the remote hosts may be waiting for data from the application before sending, but the application cannot send that data because all the threads are tied up waiting for inbound data. This is particularly important for server applications that use a daemon component.

For example, say a server application 'S' has a max thread pool size of three, and clients 'A' and 'B' connect to it and each client uploads a large file. After all uploads are complete, 'S' enqueues an asynchronous read request in the thread pool for each client. Because no work is being done, the thread pool immediately consumes two threads that wait for any further data from 'A' and 'B'. While 'S' is still processing the first two files it has received, client 'C' connects and uploads a relatively small file. Similarly, once that upload has completed 'S' enqueues a third read request, and the thread pool immediately consumes the third and final thread to wait for further data from 'C'. Once 'S' completes processing any of the files, it will enqueue a send request. However, because all three threads are in use and waiting for data from the clients, the send operation cannot be completed. The entire system becomes deadlocked because each of the clients is waiting for data from the server, which cannot send that data because all of its pool threads are in turn waiting for data from the clients.

To avoid a deadlock situation such as this, it is necessary to ensure that the maximum number of socket connections an application can make is always at least one less than the number of available worker threads. One method to achieve this is to call System.Threading.ThreadPool.SetMaxThreads during the application's startup to set the maximum number of threads to a value high enough to support the application for the duration of its execution. Another option is to trap an event such as ConnectionRequest and Disconnected from each component instance with logic to manage the maximum thread pool size according to the application's current needs.

Note: Server components are designed to process events as they occur. To ensure that events are processed in a timely manner, DoEvents should be called in a loop after the server is started.

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the component with short descriptions. Click on the links for further details.

ConnectionBacklog Property (WSServer Component)

This property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem.

Syntax

• C#
• VB.NET

public int ConnectionBacklog { get; set; }

Public Property ConnectionBacklog As Integer

Default Value

5

Remarks

This property contains the maximum number of pending connections maintained by the TCP/IP subsystem. This value reflects the SOMAXCONN option for the main listening socket. The default value for most systems is 5. You may set this property to a larger value if the server is expected to receive a large number of connections, and queuing them is desirable.

This property is not available at design time.

Connections Property (WSServer Component)

A collection of currently connected WebSocket clients.

Syntax

• C#
• VB.NET

public WSConnectionMap Connections { get; }

Public ReadOnly Property Connections As WSConnectionMap

Remarks

This property contains a collection of currently connected clients. All of the connections may be managed using this property. Each connection is described by the different fields of the WSConnection type.

This collection is a hashtable type of collection, in which the Connection ID string is used as the key to the desired connection. You may acquire the key for a given connection through the Connected or WebSocketOpenRequest events.

This property is read-only.

DefaultTimeout Property (WSServer Component)

An initial timeout value to be used by incoming connections.

Syntax

• C#
• VB.NET

public int DefaultTimeout { get; set; }

Public Property DefaultTimeout As Integer

Default Value

0

Remarks

This property is used by the component to set the operational timeout value of all inbound connections once they are established.

This property defines the timeout when sending data. When UseSSL is False a value of 0 means data will be sent asynchronously and a positive value means data is sent synchronously.

When UseSSL is True all data is sent synchronously regardless of the Timeout value.

Listening Property (WSServer Component)

If set to True, the component accepts incoming connections on LocalPort.

Syntax

• C#
• VB.NET

public bool Listening { get; set; }

Public Property Listening As Boolean

Default Value

False

Remarks

This property indicates whether the component is listening for connections on the port specified by the LocalPort property.

Note: Use the StartListening and StopListening methods to control whether the component is listening.

This property is not available at design time.

LocalHost Property (WSServer Component)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

• C#
• VB.NET

public string LocalHost { get; set; }

Public Property LocalHost As String

Default Value

""

Remarks

The LocalHost property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the component initiate connections (or accept in the case of server components) only through that interface.

If the component is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multi-homed hosts (machines with more than one IP interface).

NOTE: LocalHost is not persistent. You must always set it in code, and never in the property window.

LocalPort Property (WSServer Component)

This property includes the Transmission Control Protocol (TCP) port in the local host where the component listens.

Syntax

• C#
• VB.NET

public int LocalPort { get; set; }

Public Property LocalPort As Integer

Default Value

0

Remarks

This property must be set before the component can start listening. If its value is 0, then the TCP/IP subsystem picks a port number at random. The port number can be found by checking the value of this property after the component is listening (i.e., after successfully assigning True to the Listening property).

The service port is not shared among servers so two components cannot be listening on the same port at the same time.

SSLAuthenticateClients Property (WSServer Component)

If set to True, the server asks the client(s) for a certificate.

Syntax

• C#
• VB.NET

public bool SSLAuthenticateClients { get; set; }

Public Property SSLAuthenticateClients As Boolean

Default Value

False

Remarks

This property is used in conjunction with the SSLClientAuthentication event. Please refer to the documentation of the SSLClientAuthentication event for details.

SSLCert Property (WSServer Component)

The certificate to be used during SSL negotiation.

Syntax

• C#
• VB.NET

public Certificate SSLCert { get; set; }

Public Property SSLCert As Certificate

Remarks

The digital certificate that the component will use during SSL negotiation. Set this property to a valid certificate before starting SSL negotiation. To set a certificate, you may set the Encoded field to the encoded certificate. To select a certificate, use the store and subject fields.

ChangeLineMode Method (WSServer Component)

Controls whether the component will fire DataIn when an EOL is received for the specified connection.

Syntax

• C#
• VB.NET

public void ChangeLineMode(string connectionId, bool lineMode);

Async Version
public async Task ChangeLineMode(string connectionId, bool lineMode);
public async Task ChangeLineMode(string connectionId, bool lineMode, CancellationToken cancellationToken);

Public Sub ChangeLineMode(ByVal ConnectionId As String, ByVal LineMode As Boolean)

Async Version
Public Sub ChangeLineMode(ByVal ConnectionId As String, ByVal LineMode As Boolean) As Task
Public Sub ChangeLineMode(ByVal ConnectionId As String, ByVal LineMode As Boolean, cancellationToken As CancellationToken) As Task

Remarks

When LineMode is set to false (default), the component will fire the DataIn event once for each message received from the client. When LineMode is set to True, the component will instead fire DataIn for each line of data received. The maximum length of a line can be controlled by the MaxLineLength[ConnectionId]; configuration setting.

Note: This method is offered as a convenience feature, and has no effect on the behavior of the WebSocket protocol.

Config Method (WSServer Component)

Sets or retrieves a configuration setting.

Syntax

• C#
• VB.NET

public string Config(string configurationString);

Async Version
public async Task<string> Config(string configurationString);
public async Task<string> Config(string configurationString, CancellationToken cancellationToken);

Public Function Config(ByVal ConfigurationString As String) As String

Async Version
Public Function Config(ByVal ConfigurationString As String) As Task(Of String)
Public Function Config(ByVal ConfigurationString As String, cancellationToken As CancellationToken) As Task(Of String)

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Disconnect Method (WSServer Component)

This method disconnects the specified client.

Syntax

• C#
• VB.NET

public void Disconnect(string connectionId);

Async Version
public async Task Disconnect(string connectionId);
public async Task Disconnect(string connectionId, CancellationToken cancellationToken);

Public Sub Disconnect(ByVal ConnectionId As String)

Async Version
Public Sub Disconnect(ByVal ConnectionId As String) As Task
Public Sub Disconnect(ByVal ConnectionId As String, cancellationToken As CancellationToken) As Task

Remarks

Calling this method will disconnect the client specified by the ConnectionId parameter.

DoEvents Method (WSServer Component)

Processes events from the internal message queue.

Syntax

• C#
• VB.NET

public void DoEvents();

Async Version
public async Task DoEvents();
public async Task DoEvents(CancellationToken cancellationToken);

Public Sub DoEvents()

Async Version
Public Sub DoEvents() As Task
Public Sub DoEvents(cancellationToken As CancellationToken) As Task

Remarks

When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns.

Interrupt Method (WSServer Component)

Interrupts a synchronous send to the remote host.

Syntax

• C#
• VB.NET

public void Interrupt(string connectionId);

Async Version
public async Task Interrupt(string connectionId);
public async Task Interrupt(string connectionId, CancellationToken cancellationToken);

Public Sub Interrupt(ByVal ConnectionId As String)

Async Version
Public Sub Interrupt(ByVal ConnectionId As String) As Task
Public Sub Interrupt(ByVal ConnectionId As String, cancellationToken As CancellationToken) As Task

Remarks

This property is called using the Connection ID if you wish to interrupt a connection and stop a file from uploading without disconnecting the client connected to the component. If you use SendFile to upload a file, the component will run synchronously on that Connection ID until it is completed.

Ping Method (WSServer Component)

Sends a Ping request to the remote host.

Syntax

• C#
• VB.NET

public void Ping(string connectionId);

Async Version
public async Task Ping(string connectionId);
public async Task Ping(string connectionId, CancellationToken cancellationToken);

Public Sub Ping(ByVal ConnectionId As String)

Async Version
Public Sub Ping(ByVal ConnectionId As String) As Task
Public Sub Ping(ByVal ConnectionId As String, cancellationToken As CancellationToken) As Task

Remarks

This method sends a Ping request to the remote host and waits for a corresponding Pong response.

The Timeout property specifies how long to wait for the Pong response.

Send Method (WSServer Component)

Sends binary data to the client.

Syntax

• C#
• VB.NET

public void Send(string connectionId, byte[] data);

Async Version
public async Task Send(string connectionId, byte[] data);
public async Task Send(string connectionId, byte[] data, CancellationToken cancellationToken);

Public Sub Send(ByVal ConnectionId As String, ByVal Data As String)

Async Version
Public Sub Send(ByVal ConnectionId As String, ByVal Data As String) As Task
Public Sub Send(ByVal ConnectionId As String, ByVal Data As String, cancellationToken As CancellationToken) As Task

Remarks

This method sends the binary data specified by Data to the client specified by ConnectionId.

SendBytes Method (WSServer Component)

This method sends binary data to the specified client.

Syntax

• C#
• VB.NET

public void SendBytes(string connectionId, byte[] data);

Async Version
public async Task SendBytes(string connectionId, byte[] data);
public async Task SendBytes(string connectionId, byte[] data, CancellationToken cancellationToken);

Public Sub SendBytes(ByVal ConnectionId As String, ByVal Data As String)

Async Version
Public Sub SendBytes(ByVal ConnectionId As String, ByVal Data As String) As Task
Public Sub SendBytes(ByVal ConnectionId As String, ByVal Data As String, cancellationToken As CancellationToken) As Task

Remarks

This method sends binary data to the client identified by ConnectionId. To send text, use the SendText method instead.

When Timeout is set to 0 and SSLEnabled is set to False, the component will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with exception 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the ReadyToSend event before attempting to send data again.

Note: The ReadyToSend event is not fired when part of the data is sent successfully.

When SSLEnabled is True or Timeout is set to a positive value, the component behaves synchronously.

This method sends binary data to the client identified by ConnectionId. To send text, use the SendText method instead.

When Timeout is set to 0 and SSLEnabled is set to False, the component will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with exception 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the ReadyToSend event before attempting to send data again.

Note: The ReadyToSend event is not fired when part of the data is sent successfully.

When SSLEnabled is True or Timeout is set to a positive value, the component behaves synchronously.

SendFile Method (WSServer Component)

This method sends the file to the remote host.

Syntax

• C#
• VB.NET

public void SendFile(string connectionId, string fileName);

Async Version
public async Task SendFile(string connectionId, string fileName);
public async Task SendFile(string connectionId, string fileName, CancellationToken cancellationToken);

Public Sub SendFile(ByVal ConnectionId As String, ByVal FileName As String)

Async Version
Public Sub SendFile(ByVal ConnectionId As String, ByVal FileName As String) As Task
Public Sub SendFile(ByVal ConnectionId As String, ByVal FileName As String, cancellationToken As CancellationToken) As Task

Remarks

This method sends the file to the client specified by the ConnectionId.

Note: This method operate synchronously. DefaultTimeout or Timeout must be set to a positive value before calling this method.

SendText Method (WSServer Component)

Sends text data to the client.

Syntax

• C#
• VB.NET

public void SendText(string connectionId, string text);

Async Version
public async Task SendText(string connectionId, string text);
public async Task SendText(string connectionId, string text, CancellationToken cancellationToken);

Public Sub SendText(ByVal ConnectionId As String, ByVal Text As String)

Async Version
Public Sub SendText(ByVal ConnectionId As String, ByVal Text As String) As Task
Public Sub SendText(ByVal ConnectionId As String, ByVal Text As String, cancellationToken As CancellationToken) As Task

Remarks

This method sends text to the client identified by ConnectionId. To send binary data, use the SendBytes method instead.

When Timeout is set to 0 and SSLEnabled is set to False, the component will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with exception 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the ReadyToSend event before attempting to send data again.

Note: The ReadyToSend event is not fired when part of the data is sent successfully.

When SSLEnabled is True or Timeout is set to a positive value, the component behaves synchronously.

This method sends text to the client identified by ConnectionId. Data sent with this method will always be treated as text data regardless of the value of DataFormat. The component will UTF-8 encode the supplied text.

SetUploadStream Method (WSServer Component)

This method sends the data in the specified stream.

Syntax

• C#
• VB.NET

public void SetUploadStream(string connectionId, System.IO.Stream stream);

Async Version
public async Task SetUploadStream(string connectionId, System.IO.Stream stream);
public async Task SetUploadStream(string connectionId, System.IO.Stream stream, CancellationToken cancellationToken);

Public Sub SetUploadStream(ByVal ConnectionId As String, ByVal Stream As System.IO.Stream)

Async Version
Public Sub SetUploadStream(ByVal ConnectionId As String, ByVal Stream As System.IO.Stream) As Task
Public Sub SetUploadStream(ByVal ConnectionId As String, ByVal Stream As System.IO.Stream, cancellationToken As CancellationToken) As Task

Remarks

This method sends the data in the specified stream to the connection identified by ConnectionId. The component will automatically close this stream after sending.

Shutdown Method (WSServer Component)

This method shuts down the server.

Syntax

• C#
• VB.NET

public void Shutdown();

Async Version
public async Task Shutdown();
public async Task Shutdown(CancellationToken cancellationToken);

Public Sub Shutdown()

Async Version
Public Sub Shutdown() As Task
Public Sub Shutdown(cancellationToken As CancellationToken) As Task

Remarks

This method shuts down the server. Calling this method is equivalent to calling StopListening and then breaking every client connection by calling Disconnect.

StartListening Method (WSServer Component)

This method starts listening for incoming connections.

Syntax

• C#
• VB.NET

public void StartListening();

Async Version
public async Task StartListening();
public async Task StartListening(CancellationToken cancellationToken);

Public Sub StartListening()

Async Version
Public Sub StartListening() As Task
Public Sub StartListening(cancellationToken As CancellationToken) As Task

Remarks

This method begins listening for incoming connections on the port specified by LocalPort. Once listening, events will fire as new clients connect and data are transferred.

To stop listening for new connections, call StopListening. To stop listening for new connections and to disconnect all existing clients, call Shutdown.

StopListening Method (WSServer Component)

This method stops listening for new connections.

Syntax

• C#
• VB.NET

public void StopListening();

Async Version
public async Task StopListening();
public async Task StopListening(CancellationToken cancellationToken);

Public Sub StopListening()

Async Version
Public Sub StopListening() As Task
Public Sub StopListening(cancellationToken As CancellationToken) As Task

Remarks

This method stops listening for new connections. After being called, any new connection attempts will be rejected. Calling this method does not disconnect existing connections.

To stop listening and to disconnect all existing clients, call Shutdown instead.

Connected Event (WSServer Component)

Fired when a WebSocket is successfully opened.

Syntax

• C#
• VB.NET

public event OnConnectedHandler OnConnected;

public delegate void OnConnectedHandler(object sender, WsserverConnectedEventArgs e);

public class WsserverConnectedEventArgs : EventArgs {
  public string ConnectionId { get; }
}

Public Event OnConnected As OnConnectedHandler

Public Delegate Sub OnConnectedHandler(sender As Object, e As WsserverConnectedEventArgs)

Public Class WsserverConnectedEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
End Class

Remarks

The Connected event is fired when a WebSocket is successfully opened on a connection.

ConnectionId identifies the connection.

ConnectionRequest Event (WSServer Component)

This event is fired when a request for connection comes from a remote host.

Syntax

• C#
• VB.NET

public event OnConnectionRequestHandler OnConnectionRequest;

public delegate void OnConnectionRequestHandler(object sender, WsserverConnectionRequestEventArgs e);

public class WsserverConnectionRequestEventArgs : EventArgs {
  public string Address { get; }
  public int Port { get; }
  public bool Accept { get; set; }
}

Public Event OnConnectionRequest As OnConnectionRequestHandler

Public Delegate Sub OnConnectionRequestHandler(sender As Object, e As WsserverConnectionRequestEventArgs)

Public Class WsserverConnectionRequestEventArgs Inherits EventArgs
  Public ReadOnly Property Address As String
  Public ReadOnly Property Port As Integer
  Public Property Accept As Boolean
End Class

Remarks

This event indicates an incoming connection. The connection is accepted by default. Address and Port will contain information about the remote host requesting the inbound connection. If you want to refuse it, you can set the Accept parameter to False.

DataIn Event (WSServer Component)

Fired when data is received.

Syntax

• C#
• VB.NET

public event OnDataInHandler OnDataIn;

public delegate void OnDataInHandler(object sender, WsserverDataInEventArgs e);

public class WsserverDataInEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int DataFormat { get; }
  public string Text { get; }
  public byte[] TextB { get; }
  public bool EOM { get; }
  public bool EOL { get; }
}

Public Event OnDataIn As OnDataInHandler

Public Delegate Sub OnDataInHandler(sender As Object, e As WsserverDataInEventArgs)

Public Class WsserverDataInEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property DataFormat As Integer
  Public ReadOnly Property Text As String
  Public ReadOnly Property TextB As Byte()
  Public ReadOnly Property EOM As Boolean
  Public ReadOnly Property EOL As Boolean
End Class

Remarks

The DataIn event provides the data received from the client identified by the ConnectionId parameter.

The incoming data is provided through the Text parameter.

The DataFormat parameter identifies the encoding (if any) of the data. Possible value are:

The EOM parameter stands for End Of Message. By default the component will fire the DataIn event as data is received. Larger messages will be fragmented and will cause the event to fire multiple times. When EOM is true within the event this indicates the current fragment is also the final fragment of the message. The component may also be configured to buffer the message internally until the complete message is received. To enable this set BufferMessage to true.

The EOL parameter stands for End of Line. When LineMode is false, EOL will always be false. When LineMode is true, EOL will be True if the DataIn event fired because an EOL was received, and false if the DataIn event fired because MaxLineLength was reached.

Disconnected Event (WSServer Component)

Fired when a WebSocket connection is disconnected.

Syntax

• C#
• VB.NET

public event OnDisconnectedHandler OnDisconnected;

public delegate void OnDisconnectedHandler(object sender, WsserverDisconnectedEventArgs e);

public class WsserverDisconnectedEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int StatusCode { get; }
  public string Description { get; }
}

Public Event OnDisconnected As OnDisconnectedHandler

Public Delegate Sub OnDisconnectedHandler(sender As Object, e As WsserverDisconnectedEventArgs)

Public Class WsserverDisconnectedEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property StatusCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

When the connection is closed the StatusCode parameter may be used to determine if the disconnect occurred normally or if there was an error condition. If the connection is closed normally the StatusCode will be 1000. The Description parameter will contain a textual description returned by the server. Common StatusCode values are:

Error Event (WSServer Component)

Information about errors during data delivery.

Syntax

• C#
• VB.NET

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, WsserverErrorEventArgs e);

public class WsserverErrorEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int ErrorCode { get; }
  public string Description { get; }
}

Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As WsserverErrorEventArgs)

Public Class WsserverErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component throws an exception.

ConnectionId contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Log Event (WSServer Component)

Fires once for each log message.

Syntax

• C#
• VB.NET

public event OnLogHandler OnLog;

public delegate void OnLogHandler(object sender, WsserverLogEventArgs e);

public class WsserverLogEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int LogLevel { get; }
  public string Message { get; }
  public string LogType { get; }
}

Public Event OnLog As OnLogHandler

Public Delegate Sub OnLogHandler(sender As Object, e As WsserverLogEventArgs)

Public Class WsserverLogEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property LogLevel As Integer
  Public ReadOnly Property Message As String
  Public ReadOnly Property LogType As String
End Class

Remarks

This event fires once for each log message generated by the component. The verbosity is controlled by the LogLevel setting.

LogLevel indicates the level of message. Possible values are:

The value 1 (Info) logs basic information including the URL, HTTP version, and connection status details.

The value 2 (Verbose) logs additional information about the initial HTTP request.

The value 3 (Debug) logs additional debug information (if available).

Message is the log entry.

LogType identifies the type of log entry. Possible values are:

• "Info"
• "Error"
• "Verbose"
• "Debug"

Ping Event (WSServer Component)

Fired when a ping request or response is received.

Syntax

• C#
• VB.NET

public event OnPingHandler OnPing;

public delegate void OnPingHandler(object sender, WsserverPingEventArgs e);

public class WsserverPingEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string Payload { get; }
  public byte[] PayloadB { get; }
  public bool Response { get; }
}

Public Event OnPing As OnPingHandler

Public Delegate Sub OnPingHandler(sender As Object, e As WsserverPingEventArgs)

Public Class WsserverPingEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property Payload As String
  Public ReadOnly Property PayloadB As Byte()
  Public ReadOnly Property Response As Boolean
End Class

Remarks

This event fires when a ping request or response is received from the client identified by the ConnectionId parameter. This event is informational only. When the component receives a ping request it will automatically reply with a pong.

Payload holds the payload of the request, if any.

Response is true if the incoming packet is a ping response. If the incoming packet is a ping request this is false.

ReadyToSend Event (WSServer Component)

This event is fired when the component is ready to send data.

Syntax

• C#
• VB.NET

public event OnReadyToSendHandler OnReadyToSend;

public delegate void OnReadyToSendHandler(object sender, WsserverReadyToSendEventArgs e);

public class WsserverReadyToSendEventArgs : EventArgs {
  public string ConnectionId { get; }
}

Public Event OnReadyToSend As OnReadyToSendHandler

Public Delegate Sub OnReadyToSendHandler(sender As Object, e As WsserverReadyToSendEventArgs)

Public Class WsserverReadyToSendEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
End Class

Remarks

The ReadyToSend event indicates that the underlying Transmission Control Protocol (TCP)/IP subsystem is ready to accept data after a failed DataToSend. This event is also fired immediately after a connection is established.

SSLClientAuthentication Event (WSServer Component)

This event is fired when the client presents its credentials to the server.

Syntax

• C#
• VB.NET

public event OnSSLClientAuthenticationHandler OnSSLClientAuthentication;

public delegate void OnSSLClientAuthenticationHandler(object sender, WsserverSSLClientAuthenticationEventArgs e);

public class WsserverSSLClientAuthenticationEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string CertEncoded { get; }
  public byte[] CertEncodedB { get; }
  public string CertSubject { get; }
  public string CertIssuer { get; }
  public string Status { get; }
  public bool Accept { get; set; }
}

Public Event OnSSLClientAuthentication As OnSSLClientAuthenticationHandler

Public Delegate Sub OnSSLClientAuthenticationHandler(sender As Object, e As WsserverSSLClientAuthenticationEventArgs)

Public Class WsserverSSLClientAuthenticationEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property CertEncoded As String
  Public ReadOnly Property CertEncodedB As Byte()
  Public ReadOnly Property CertSubject As String
  Public ReadOnly Property CertIssuer As String
  Public ReadOnly Property Status As String
  Public Property Accept As Boolean
End Class

Remarks

This event enables the server to decide whether or not to continue. The Accept parameter is a recommendation on whether to continue or to close the connection. This is just a suggestion: application software must use its own logic to determine whether or not to continue.

When Accept is False, Status shows why the verification failed (otherwise, Status contains the string "OK").

SSLConnectionRequest Event (WSServer Component)

This event fires when a Secure Sockets Layer (SSL) connection is requested.

Syntax

• C#
• VB.NET

public event OnSSLConnectionRequestHandler OnSSLConnectionRequest;

public delegate void OnSSLConnectionRequestHandler(object sender, WsserverSSLConnectionRequestEventArgs e);

public class WsserverSSLConnectionRequestEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string SupportedCipherSuites { get; }
  public string SupportedSignatureAlgs { get; }
  public int CertStoreType { get; set; }
  public string CertStore { get; set; }
  public string CertPassword { get; set; }
  public string CertSubject { get; set; }
}

Public Event OnSSLConnectionRequest As OnSSLConnectionRequestHandler

Public Delegate Sub OnSSLConnectionRequestHandler(sender As Object, e As WsserverSSLConnectionRequestEventArgs)

Public Class WsserverSSLConnectionRequestEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property SupportedCipherSuites As String
  Public ReadOnly Property SupportedSignatureAlgs As String
  Public Property CertStoreType As Integer
  Public Property CertStore As String
  Public Property CertPassword As String
  Public Property CertSubject As String
End Class

Remarks

This event fires when an SSL connection is requested and SSLProvider is set to Internal. This event provides an opportunity to select an alternative certificate to the connecting client. This event does not fire when SSLProvider is set to Platform.

This event allows the component to be configured to use both RSA and ECDSA certificates depending on the connecting client's capabilities.

ConnectionId is the connection Id of the client requesting the connection.

SupportedCipherSuites is a comma-separated list of cipher suites that the client supports.

SupportedSignatureAlgs is a comma-separated list of certificate signature algorithms that the client supports.

CertStoreType is the store type of the alternate certificate to use for this connection. The component supports both public and private keys in a variety of formats. When the cstAuto value is used the component will automatically determine the type. This field can take one of the following values:

CertStore is the store name or location of the alternate certificate to use for this connection.

Designations of certificate stores are platform-dependent.

The following are designations of the most common User and Machine certificate stores in Windows:

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e. PKCS12 certificate store).

CertPassword is the password of the certificate store containing the alternate certificate to use for this connection.

CertSubject is the subject of the alternate certificate to use for this connection.

The special value * matches any subject and will select the first certificate in the store. The certificate subject is a comma separated list of distinguished name fields and values. For instance "CN=www.server.com, OU=test, C=US, E=support@nsoftware.com". Common fields and their meanings are displayed below.

If a field value contains a comma it must be quoted.

SSLStatus Event (WSServer Component)

This event is fired to show the progress of the secure connection.

Syntax

• C#
• VB.NET

public event OnSSLStatusHandler OnSSLStatus;

public delegate void OnSSLStatusHandler(object sender, WsserverSSLStatusEventArgs e);

public class WsserverSSLStatusEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string Message { get; }
}

Public Event OnSSLStatus As OnSSLStatusHandler

Public Delegate Sub OnSSLStatusHandler(sender As Object, e As WsserverSSLStatusEventArgs)

Public Class WsserverSSLStatusEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property Message As String
End Class

Remarks

The event is fired for informational and logging purposes only. It is used to track the progress of the connection.

WebSocketOpenRequest Event (WSServer Component)

Fired when a client attempts to open a WebSocket.

Syntax

• C#
• VB.NET

public event OnWebSocketOpenRequestHandler OnWebSocketOpenRequest;

public delegate void OnWebSocketOpenRequestHandler(object sender, WsserverWebSocketOpenRequestEventArgs e);

public class WsserverWebSocketOpenRequestEventArgs : EventArgs {
  public string ConnectionId { get; }
  public string RequestURI { get; }
  public string HostHeader { get; }
  public string OriginHeader { get; }
  public string SubProtocols { get; set; }
  public string Extensions { get; }
  public string RequestHeaders { get; }
  public int StatusCode { get; set; }
  public string ResponseHeaders { get; set; }
}

Public Event OnWebSocketOpenRequest As OnWebSocketOpenRequestHandler

Public Delegate Sub OnWebSocketOpenRequestHandler(sender As Object, e As WsserverWebSocketOpenRequestEventArgs)

Public Class WsserverWebSocketOpenRequestEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property RequestURI As String
  Public ReadOnly Property HostHeader As String
  Public ReadOnly Property OriginHeader As String
  Public Property SubProtocols As String
  Public ReadOnly Property Extensions As String
  Public ReadOnly Property RequestHeaders As String
  Public Property StatusCode As Integer
  Public Property ResponseHeaders As String
End Class

Remarks

This event fires when a client connects. It provides an opportunity to inspect the WebSocket request and either accept or reject the connection attempt.

By default, the component will accept the connection. You do not need to set anything to accept the connection. The component will return a StatusCode of 101 to the connecting client and the request will proceed as normal. To reject a connection, set StatusCode to an HTTP error code, such as 401.

ConnectionId identifies the connecting client.

RequestURI provides the URI requested by the connecting client. This may be used to implement logic to select appropriate SubProtocols or determine if the connection should be accepted based on access restrictions to the URI.

HostHeader holds the value of the Host header sent by the client.

OriginHeader holds the value of the Origin header sent by the client.

SubProtocols holds a comma separated list of subprotocols sent by the client (if any). Set SubProtocols to the selected value from the list sent by the client. The component will return this value to the client as the subprotocol the server has selected.

Extensions provides a list of extensions supported by the client.

RequestHeaders contains the HTTP headers sent in the request by the connecting client.

StatusCode determines success or failure. The value 101 (default) indicates success. This may be set to any HTTP status code. For instance a value of 401 indicates an authorization failure.

ResponseHeaders may be set to include additional headers in the response. This is typically used when rejecting a request. For instance when StatusCode is set to 401 you might set ResponseHeaders to "WWW-Authenticate: Basic realm="Secure Realm"" to request authorization from the connecting client.

Certificate Type

This is the digital certificate being used.

Remarks

This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates.

Fields

Constructors

• C#
• VB.NET

public Certificate();

Public Certificate()

Creates a Certificate instance whose properties can be set. This is useful for use with CERTMGR when generating new certificates.

• C#
• VB.NET

public Certificate(string certificateFile);

Public Certificate(ByVal CertificateFile As String)

Opens CertificateFile and reads out the contents as an X509 public key.

• C#
• VB.NET

public Certificate(byte[] certificateData);

Public Certificate(ByVal CertificateData As Byte())

Parses CertificateData as an X509 public key.

• C#
• VB.NET

public Certificate(CertStoreTypes certStoreType, string store, string storePassword, string subject);

Public Certificate(ByVal CertStoreType As CertStoreTypes, ByVal Store As String, ByVal StorePassword As String, ByVal Subject As String)

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

• C#
• VB.NET

public Certificate(CertStoreTypes certStoreType, string store, string storePassword, string subject, string configurationString);

Public Certificate(ByVal CertStoreType As CertStoreTypes, ByVal Store As String, ByVal StorePassword As String, ByVal Subject As String, ByVal ConfigurationString As String)

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. ConfigurationString is a newline separated list of name-value pairs that may be used to modify the default behavior. Possible values include "PersistPFXKey", which shows whether or not the PFX key is persisted after performing operations with the private key. This correlates to the PKCS12_NO_PERSIST_KEY CyrptoAPI option. The default value is True (the key is persisted). "Thumbprint" - a MD5, SHA1, or SHA256 thumbprint of the certificate to load. When specified, this value is used to select the certificate in the store. This is applicable to cstUser, cstMachine, cstPublicKeyFile, and cstPFXFile store types. "UseInternalSecurityAPI" shows whether the platform (default) or the internal security API is used when performing certificate-related operations. After the store has been successfully opened, the component will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

• C#
• VB.NET

public Certificate(CertStoreTypes certStoreType, string store, string storePassword, byte[] encoded);

Public Certificate(ByVal CertStoreType As CertStoreTypes, ByVal Store As String, ByVal StorePassword As String, ByVal Encoded As Byte())

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will load Encoded as an X509 certificate and search the opened store for a corresponding private key.

• C#
• VB.NET

public Certificate(CertStoreTypes certStoreType, byte[] storeBlob, string storePassword, string subject);

Public Certificate(ByVal CertStoreType As CertStoreTypes, ByVal StoreBlob As Byte(), ByVal StorePassword As String, ByVal Subject As String)

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. StoreBlob is a string (binary- or base64-encoded) containing the certificate data. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

• C#
• VB.NET

public Certificate(CertStoreTypes certStoreType, byte[] storeBlob, string storePassword, string subject, string configurationString);

Public Certificate(ByVal CertStoreType As CertStoreTypes, ByVal StoreBlob As Byte(), ByVal StorePassword As String, ByVal Subject As String, ByVal ConfigurationString As String)

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. StoreBlob is a string (binary- or base64-encoded) containing the certificate data. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

• C#
• VB.NET

public Certificate(CertStoreTypes certStoreType, byte[] storeBlob, string storePassword, byte[] encoded);

Public Certificate(ByVal CertStoreType As CertStoreTypes, ByVal StoreBlob As Byte(), ByVal StorePassword As String, ByVal Encoded As Byte())

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a string (binary- or base64-encoded) containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the component will load Encoded as an X509 certificate and search the opened store for a corresponding private key.

WSConnection Type

A currently connected client.

Remarks

This type describes the connection of a client which is currently connected to the component. You may use the different fields of this type to manage the connection.

Fields

Constructors

• C#
• VB.NET

public WSConnection();

Public WSConnection()

Config Settings (WSServer Component)

WebSocketServer Config Settings

TCPServer Config Settings

SSL Config Settings

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
..
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
..
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

Base Config Settings

Trappable Errors (WSServer Component)

WSServer Errors

SSLServer Errors

SSL Errors

TCP/IP Errors