DTLSClient Component

Properties Methods Events Config Settings Errors

The DTLSClient component provides client-side functionality for secure UDP communication utilizing the Datagram Transport Layer Security (DTLS) protocol.

Syntax

nsoftware.IPWorksDTLS.DTLSClient

Remarks

The DTLSClient component functions as a client that facilitates in connecting to DTLS servers and offers a convenient means of transmitting and receiving datagrams over the established, secure connection.

Connecting to a Server

First, the RemoteHost and RemotePort must be set to the address and port of the target DTLS server. The Timeout property can be used to specify a timeout when connecting to the server. To initiate the connection, call Connect.

After doing so, the handshake process will begin. Relevant handshake details will be reported by the SSLStatus event. Initially, the server will present its certificate to the client. The certificate can be evaluated within the SSLServerAuthentication event. By default, the component will provide a recommendation of whether to accept or reject the certificate, and reasoning behind the recommendation. Regardless, the certificate can be manually accepted (or rejected) within this event.

In some cases, the server requires the client to present a certificate as well. In this case, a valid certificate will need to be specified via the SSLCert property.

Once the connection is complete (or fails), the Connected event will fire. Note that this event will fire if a connection succeeds or fails. If successful, the event will fire with a StatusCode of 0. If this value is non-zero, it indicates the connection was unsuccessful. The Description parameter will contain relevant details. Upon successful connection, the Connected property will be set to True. This process may look like the following:

dtlsclient.OnConnected += (o, e) => { if (e.StatusCode == 0) { Console.WriteLine("Connection successful!"); } else { Console.WriteLine("Connection failed."); Console.WriteLine("Error code: " + e.StatusCode); Console.WriteLine("Error description: " + e.Description); } }; dtlsclient.OnSSLServerAuthentication += (o, e) => { if (e.Accept) return; Console.Write("Server provided the following certificate:\nIssuer: " + e.CertIssuer + "\nSubject: " + e.CertSubject + "\n"); Console.Write("The following problems have been determined for this certificate: " + e.Status + "\n"); Console.Write("Would you like to accept anyways? [y/n] "); if (Console.Read() == 'y') e.Accept = true; }; dtlsclient.RemoteHost = "remote_ip"; dtlsclient.RemotePort = 1234; dtlsclient.Timeout = 30; // if client authentication is applicable dtlsclient.SSLCert = new Certificate("/path/to/cert.pfx", CertStoreTypes.cstPFXFile, "cert_password", "cert_subject"); dtlsclient.Connect();

Sending and Receiving Data

Once a successful connection is established, the component can send data to the server via SendText or SendBytes.

The component will also be able to receive data from the server via the DataIn event. Note that this event is non-reentrant, and it is recommended to offload time-consuming operations to ensure the best performance.

If required, the PauseData method can be called, disabling the reception of incoming data from the server. Data reception can later be enabled via the ProcessData method. Note that if this reception is disabled, the server may continue sending data, which will remain unprocessed by the component. In this case, the underlying socket buffer may be filled. This can result in possible data loss originating from the server. Please use these methods with caution.

The complete process may look like the following:

dtlsclient.OnSSLServerAuthentication += (o, e) => { e.Accept = true; }; dtlsclient.OnDataIn += (o, e) => { Console.WriteLine("Packet received from server."); Console.WriteLine("Datagram: " + e.Datagram); } dtlsclient.RemoteHost = "remote_ip"; dtlsclient.RemotePort = 1234; dtlsclient.Connect(); dtlsclient.SendText("Hello World!"); while (true) { dtlsclient.DoEvents(); }

Disconnecting from a Server

Once the connection to the server is broken, the Disconnected event will fire. The disconnection can be performed by calling Disconnect, or performed by the server.

In the case a connection ends and an error is encountered, the StatusCode and Description parameters will contain relevant details regarding the error. For example:

dtlsclient.OnDisconnected += (o, e) => { if (e.StatusCode == 0) { Console.WriteLine("Connection ended."); } else { Console.WriteLine("Connection ended."); Console.WriteLine("Error code: " + e.StatusCode); Console.WriteLine("Error description: " + e.Description); } }; dtlsclient.RemoteHost = "remote_ip"; dtlsclient.RemotePort = 1234; dtlsclient.Connect(); ... ... ... dtlsclient.Disconnect();

Additional Information

To support KeepAlive functionality, it is important to note that DoEvents must be called regularly in both console and form-based applications. This is to ensure the component sends keep-alive (or Heartbeat) packets to the server in a timely manner.

In form-based applications, this does not apply if KeepAlive is False.

Property List

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


AcceptData	This property indicates whether data reception is currently enabled.
Connected	This property indicates whether the component is connected.
KeepAlive	When True, keep-alive functionality is enabled via the DTLS Heartbeat Extension.
LocalHost	The name of the local host or user-assigned IP interface through which connections are initiated or accepted.
LocalPort	This property includes the User Datagram Protocol (UDP) port in the local host where UDP binds.
RemoteHost	This property includes the address of the remote host. Domain names are resolved to IP addresses.
RemotePort	This property specifies the User Datagram Protocol (UDP) port in the remote host.
SSLAcceptServerCert	Instructs the component to unconditionally accept the server certificate that matches the supplied certificate.
SSLCert	The certificate to be used during Secure Sockets Layer (SSL) negotiation.
SSLServerCert	The server certificate for the last established connection.
Timeout	This property specifies a timeout when connecting to a server.

Method List

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


Config	Sets or retrieves a configuration setting.
Connect	This method connects to a remote host.
Disconnect	This method disconnects from the remote host.
DoEvents	This method processes events from the internal message queue.
PauseData	This method pauses data reception.
ProcessData	This method reenables data reception after a call to PauseData
Reset	This method will reset the component.
SendBytes	This method sends binary data to the remote host.
SendText	This method sends text to the remote host.

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.


Connected	This event is fired immediately after a connection completes (or fails).
DataIn	This event is fired when data are received.
Disconnected	This event is fired when a connection is closed.
Error	Fired when information is available about errors during data delivery.
Log	This event fires once for each log message.
SSLServerAuthentication	This event is fired after the server presents its certificate to the client.
SSLStatus	Fired when secure connection progress messages are available.

Config Settings

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


KeepAliveInterval	The retry interval, in seconds, to be used when a HeartbeatRequest is sent and no response is received.
KeepAliveMode	Specifies the Heartbeat (or keep-alive) mode to be used by the component.
KeepAliveTime	The inactivity time, in seconds, before a HeartbeatRequest is sent.
LogLevel	This configuration controls the level of detail that is logged through the Log event.
CaptureIPPacketInfo	Used to capture the packet information.
DelayHostResolution	Whether the hostname is resolved when RemoteHost is set.
DestinationAddress	Used to get the destination address from the packet information.
DontFragment	Used to set the Don't Fragment flag of outgoing packets.
LocalHost	The name of the local host through which connections are initiated or accepted.
LocalPort	The port in the local host where the component binds.
MaxPacketSize	The maximum length of the packets that can be received.
QOSDSCPValue	Used to specify an arbitrary QOS/DSCP setting (optional).
QOSTrafficType	Used to specify QOS/DSCP settings (optional).
ShareLocalPort	If set to True, allows more than one instance of the component to be active on the same local port.
UseConnection	Determines whether to use a connected socket.
UseIPv6	Whether or not to use IPv6.
AbsoluteTimeout	Determines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallData	Used to send extra data to the firewall.
InBufferSize	The size in bytes of the incoming queue of the socket.
OutBufferSize	The size in bytes of the outgoing queue of the socket.
CACertFilePaths	The paths to CA certificate files when using Mono on Unix/Linux.
LogSSLPackets	Controls whether SSL packets are logged.
ReuseSSLSession	Determines if the SSL session is reused.
SSLCACerts	A newline separated list of CA certificates to be included when performing an SSL handshake.
SSLCheckCRL	Whether to check the Certificate Revocation List for the server certificate.
SSLCheckOCSP	Whether to use OCSP to check the status of the server certificate.
SSLCipherStrength	The minimum cipher strength used for bulk encryption.
SSLClientCACerts	A newline separated list of CA certificates to use during SSL client certificate validation.
SSLEnabledCipherSuites	Specifies the cipher suites to be used during TLS negotiation.
SSLEnabledProtocols	Used to enable/disable the supported security protocols.
SSLEnableRenegotiation	Whether the renegotiation_info SSL extension is supported.
SSLKeyLogFile	The location of a file where per-session secrets are written for debugging purposes.
SSLNegotiatedCipher	Returns the negotiated cipher suite.
SSLNegotiatedCipherStrength	Returns the negotiated cipher suite strength.
SSLNegotiatedCipherSuite	Returns the negotiated cipher suite.
SSLNegotiatedKeyExchange	Returns the negotiated key exchange algorithm.
SSLNegotiatedKeyExchangeStrength	Returns the negotiated key exchange algorithm strength.
SSLNegotiatedVersion	Returns the negotiated protocol version.
SSLSecurityFlags	Flags that control certificate verification.
SSLServerCACerts	A newline separated list of CA certificates to use during SSL server certificate validation.
TLS12SignatureAlgorithms	Defines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal.
TLS12SupportedGroups	The supported groups for ECC.
BuildInfo	Information about the product's build.
GUIAvailable	Whether or not a message loop is available for processing events.
LicenseInfo	Information about the current license.
MaskSensitiveData	Whether sensitive data is masked in log messages.
UseInternalSecurityAPI	Whether or not to use the system security libraries or an internal implementation.

AcceptData Property (DTLSClient Component)

This property indicates whether data reception is currently enabled.

public bool AcceptData { get; }

Public ReadOnly Property AcceptData As Boolean

Default Value

True

Remarks

This property indicates whether data reception is currently enabled. When false, data reception is disabled and the DataIn event will not fire. Use the PauseData and ProcessData methods to pause and resume data reception.

This property is read-only and not available at design time.

Connected Property (DTLSClient Component)

This property indicates whether the component is connected.

Syntax

C#
VB.NET

public bool Connected { get; }

Public ReadOnly Property Connected As Boolean

Default Value

False

Remarks

This property indicates whether the component is connected to the remote host. Use the Connect and Disconnect methods to manage the connection.

This property is read-only and not available at design time.

KeepAlive Property (DTLSClient Component)

When True, keep-alive functionality is enabled via the DTLS Heartbeat Extension.

Syntax

C#
VB.NET

public bool KeepAlive { get; set; }

Public Property KeepAlive As Boolean

Default Value

False

Remarks

This property enables keep-alive functionality for the established connection via the DTLS Heartbeat Extension (RFC 6520). Enabling this option can prevent a long connection from timing out in case of inactivity.

Note: For this functionality to work as intended, DoEvents must be called frequently in both console and form-based applications (e.g., using a loop or timer).

Additionally, DTLS server implementations are not required to support Heartbeats.

LocalHost Property (DTLSClient 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

This 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 multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the component initiate connections (or accept in the case of server components) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

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 multihomed 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 (DTLSClient Component)

This property includes the User Datagram Protocol (UDP) port in the local host where UDP binds.

Syntax

C#
VB.NET

public int LocalPort { get; set; }

Public Property LocalPort As Integer

Default Value

Remarks

The LocalPort property must be set before UDP is activated (Active is set to True). This instructs the component to bind to a specific port (or communication endpoint) in the local machine.

Setting it to 0 (default) enables the Transmission Control Protocol (TCP)/IP stack to choose a port at random. The chosen port will be shown by the LocalPort property after the connection is established.

LocalPort cannot be changed once the component is Active. Any attempt to set the LocalPort property when the component is Active will generate an error.

The LocalPort property is useful when trying to connect to services that require a trusted port on the client side.

RemoteHost Property (DTLSClient Component)

This property includes the address of the remote host. Domain names are resolved to IP addresses.

Syntax

C#
VB.NET

public string RemoteHost { get; set; }

Public Property RemoteHost As String

Default Value

Remarks

The RemoteHost property specifies the IP address (IP number in dotted internet format) or domain name of the remote host.

If RemoteHost is set to 255.255.255.255, the component broadcasts data on the local subnet.

If the RemoteHost property is set to a domain name, a DNS request is initiated, and upon successful termination of the request, the RemoteHost property is set to the corresponding address. If the search is not successful, an error is returned.

If UseConnection is set to True, the RemoteHost must be set before the component is activated (Active is set to True).

RemotePort Property (DTLSClient Component)

This property specifies the User Datagram Protocol (UDP) port in the remote host.

Syntax

C#
VB.NET

public int RemotePort { get; set; }

Public Property RemotePort As Integer

Default Value

Remarks

The RemotePort is the UDP port on the RemoteHost to send UDP datagrams to.

A valid port number (a value between 1 and 65535) is required.

If UseConnection is set to True, the RemotePort must be set before the component is activated (Active is set to True).

SSLAcceptServerCert Property (DTLSClient Component)

Instructs the component to unconditionally accept the server certificate that matches the supplied certificate.

Syntax

C#
VB.NET

public Certificate SSLAcceptServerCert { get; set; }

Public Property SSLAcceptServerCert As Certificate

Remarks

If it finds any issues with the certificate presented by the server, the component will normally terminate the connection with an error.

You may override this behavior by supplying a value for SSLAcceptServerCert. If the certificate supplied in SSLAcceptServerCert is the same as the certificate presented by the server, then the server certificate is accepted unconditionally, and the connection will continue normally.

Note: This functionality is provided only for cases in which you otherwise know that you are communicating with the right server. If used improperly, this property may create a security breach. Use it at your own risk.

Please refer to the Certificate type for a complete list of fields.

SSLCert Property (DTLSClient Component)

The certificate to be used during Secure Sockets Layer (SSL) negotiation.

Syntax

C#
VB.NET

public Certificate SSLCert { get; set; }

Public Property SSLCert As Certificate

Remarks

This property includes 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.

Please refer to the Certificate type for a complete list of fields.

SSLServerCert Property (DTLSClient Component)

The server certificate for the last established connection.

Syntax

C#
VB.NET

public Certificate SSLServerCert { get; }

Public ReadOnly Property SSLServerCert As Certificate

Remarks

This property contains the server certificate for the last established connection.

SSLServerCert is reset every time a new connection is attempted.

This property is read-only.

Please refer to the Certificate type for a complete list of fields.

Timeout Property (DTLSClient Component)

This property specifies a timeout when connecting to a server.

Syntax

C#
VB.NET

public int Timeout { get; set; }

Public Property Timeout As Integer

Default Value

Remarks

This property specifies a timeout when connecting to a server. When calling Connect, if the connection is not established within Timeout seconds, an error is thrown.

Config Method (DTLSClient 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.

Connect Method (DTLSClient Component)

This method connects to a remote host.

Syntax

C#
VB.NET

public void Connect();

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

Public Sub Connect()

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

Remarks

This method connects to the remote host specified by RemoteHost and RemotePort. For instance: component.RemoteHost = "MyHostNameOrIP"; component.RemotePort = 7777; component.Connect();

Disconnect Method (DTLSClient Component)

This method disconnects from the remote host.

Syntax

C#
VB.NET

public void Disconnect();

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

Public Sub Disconnect()

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

Remarks

This method disconnects from the remote host. Calling this method is equivalent to setting the Connected property to False.

DoEvents Method (DTLSClient Component)

This method 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.

PauseData Method (DTLSClient Component)

This method pauses data reception.

Syntax

C#
VB.NET

public void PauseData();

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

Public Sub PauseData()

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

Remarks

This method pauses data reception when called. While data reception is paused, the DataIn event will not fire. Call ProcessData to reenable data reception.

ProcessData Method (DTLSClient Component)

This method reenables data reception after a call to PauseData

Syntax

C#
VB.NET

public void ProcessData();

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

Public Sub ProcessData()

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

Remarks

This method reenables data reception after a previous call to PauseData. When PauseData is called, the DataIn event will not fire. To reenable data reception and allow DataIn to fire, call this method.

Note: This method is used only after previously calling PauseData. It does not need to be called to process incoming data by default.

Reset Method (DTLSClient Component)

This method will reset the component.

Syntax

C#
VB.NET

public void Reset();

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

Public Sub Reset()

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

Remarks

This method will reset the component's properties to their default values.

SendBytes Method (DTLSClient Component)

This method sends binary data to the remote host.

Syntax

C#
VB.NET

public void SendBytes(byte[] data);

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

Public Sub SendBytes(ByVal Data As String)

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

Remarks

This method sends the specified binary data to the remote host. For example:

byte[] dataToSend = new byte[] { 72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100, 33 }; dtlsclient.SendBytes(dataToSend);

To send text, use the SendText method instead.

SendText Method (DTLSClient Component)

This method sends text to the remote host.

Syntax

C#
VB.NET

public void SendText(string text);

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

Public Sub SendText(ByVal Text As String)

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

Remarks

This method sends the specified text to the remote host. For example:

dtlsclient.onSSLServerAuthentication += (o, e) => { e.Accept = true; }; dtlsclient.RemotePort = 8765; dtlsclient.RemoteHost = "HostNameOrIPAddress"; dtlsclient.Connect(); dtlsclient.SendText("Hello!");

To send binary data, use the SendBytes method instead.

Connected Event (DTLSClient Component)

This event is fired immediately after a connection completes (or fails).

Syntax

C#
VB.NET

public event OnConnectedHandler OnConnected;

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

public class DTLSClientConnectedEventArgs : EventArgs {
  public string Address { get; }
  public int Port { get; }
  public int StatusCode { get; }
  public string Description { get; }
}

Public Event OnConnected As OnConnectedHandler

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

Public Class DTLSClientConnectedEventArgs Inherits EventArgs
  Public ReadOnly Property Address As String
  Public ReadOnly Property Port As Integer
  Public ReadOnly Property StatusCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

This event is fired immediately after a connection completes (or fails).

If the connection is made normally, StatusCode is 0 and Description is "OK".

If the connection is broken for any other reason, StatusCode will be non-zero, and the Description parameter will contain a description of this code.

DataIn Event (DTLSClient Component)

This event is fired when data are received.

Syntax

C#
VB.NET

public event OnDataInHandler OnDataIn;

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

public class DTLSClientDataInEventArgs : EventArgs {
  public string Datagram { get; }
  public byte[] DatagramB { get; }
  public string SourceAddress { get; }
  public int SourcePort { get; }
}

Public Event OnDataIn As OnDataInHandler

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

Public Class DTLSClientDataInEventArgs Inherits EventArgs
  Public ReadOnly Property Datagram As String
  Public ReadOnly Property DatagramB As Byte()
  Public ReadOnly Property SourceAddress As String
  Public ReadOnly Property SourcePort As Integer
End Class

Remarks

The DataIn event is fired every time a new datagram is received.

Datagram contains the packet as sent by the remote host.

SourceAddress contains the IP number (Internet address) of the remote host, and SourcePort contains the port from which the packet originated.

Note: Events are not re-entrant. Performing time-consuming operations within this event will prevent it from firing again in a timely manner and may affect overall performance.

Disconnected Event (DTLSClient Component)

This event is fired when a connection is closed.

Syntax

C#
VB.NET

public event OnDisconnectedHandler OnDisconnected;

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

public class DTLSClientDisconnectedEventArgs : EventArgs {
  public string Address { get; }
  public int Port { get; }
  public int StatusCode { get; }
  public string Description { get; }
}

Public Event OnDisconnected As OnDisconnectedHandler

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

Public Class DTLSClientDisconnectedEventArgs Inherits EventArgs
  Public ReadOnly Property Address As String
  Public ReadOnly Property Port As Integer
  Public ReadOnly Property StatusCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

This event is fired when a connection is closed.

If the connection is broken normally, StatusCode is 0 and Description is "OK".

If the connection is broken for any other reason, StatusCode will be non-zero, and the Description parameter will contain a description of this code.

Error Event (DTLSClient Component)

Fired when information is available about errors during data delivery.

Syntax

C#
VB.NET

public event OnErrorHandler OnError;

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

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

Public Event OnError As OnErrorHandler

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

Public Class DTLSClientErrorEventArgs Inherits EventArgs
  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.

The ErrorCode parameter contains an error code, and the Description parameter 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 (DTLSClient Component)

This event fires once for each log message.

Syntax

C#
VB.NET

public event OnLogHandler OnLog;

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

public class DTLSClientLogEventArgs : EventArgs {
  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 DTLSClientLogEventArgs)

Public Class DTLSClientLogEventArgs Inherits EventArgs
  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 as follows:


0 (None)	No events are logged.
1 (Info - default)	Informational events are logged.
2 (Verbose)	Detailed data are logged.
3 (Debug)	Debug data are logged.

The value 1 (Info) logs basic information, including users logging in and out, files transferred, and directories listed.

The value 2 (Verbose) includes logs from the PITrail event as well as basic information about data transfer channels.

The value 3 (Debug) logs additional debug information, such as extended socket connection and data transfer information.

Message is the log entry.

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

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

SSLServerAuthentication Event (DTLSClient Component)

This event is fired after the server presents its certificate to the client.

Syntax

C#
VB.NET

public event OnSSLServerAuthenticationHandler OnSSLServerAuthentication;

public delegate void OnSSLServerAuthenticationHandler(object sender, DTLSClientSSLServerAuthenticationEventArgs e);

public class DTLSClientSSLServerAuthenticationEventArgs : EventArgs {
  public string SourceAddress { get; }
  public int SourcePort { 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 OnSSLServerAuthentication As OnSSLServerAuthenticationHandler

Public Delegate Sub OnSSLServerAuthenticationHandler(sender As Object, e As DTLSClientSSLServerAuthenticationEventArgs)

Public Class DTLSClientSSLServerAuthenticationEventArgs Inherits EventArgs
  Public ReadOnly Property SourceAddress As String
  Public ReadOnly Property SourcePort As Integer
  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 is fired after the server presents its certificate to the client.

During this event, the client can decide whether or not to continue with the connection process. The Accept parameter is a recommendation on whether to continue or 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). If it is decided to continue, you can override and accept the certificate by setting the Accept parameter to True.

SSLStatus Event (DTLSClient Component)

Fired when secure connection progress messages are available.

Syntax

C#
VB.NET

public event OnSSLStatusHandler OnSSLStatus;

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

public class DTLSClientSSLStatusEventArgs : EventArgs {
  public string Message { get; }
}

Public Event OnSSLStatus As OnSSLStatusHandler

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

Public Class DTLSClientSSLStatusEventArgs Inherits EventArgs
  Public ReadOnly Property Message As String
End Class

Remarks

The event is fired for informational and logging purposes only. This event tracks the progress of the connection.

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.

The following fields are available:

Fields

EffectiveDate
string (read-only)
Default: ""

The date on which this certificate becomes valid. Before this date, it is not valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date:

23-Jan-2000 15:00:00.

ExpirationDate
string (read-only)
Default: ""

The date on which the certificate expires. After this date, the certificate will no longer be valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date:

23-Jan-2001 15:00:00.

ExtendedKeyUsage
string (read-only)
Default: ""

A comma-delimited list of extended key usage identifiers. These are the same as ASN.1 object identifiers (OIDs).

Fingerprint
string (read-only)
Default: ""

The hex-encoded, 16-byte MD5 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

The following example illustrates the format: bc:2a:72:af:fe:58:17:43:7a:5f:ba:5a:7c:90:f7:02

FingerprintSHA1
string (read-only)
Default: ""

The hex-encoded, 20-byte SHA-1 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

The following example illustrates the format: 30:7b:fa:38:65:83:ff:da:b4:4e:07:3f:17:b8:a4:ed:80:be:ff:84

FingerprintSHA256
string (read-only)
Default: ""

The hex-encoded, 32-byte SHA-256 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

The following example illustrates the format: 6a:80:5c:33:a9:43:ea:b0:96:12:8a:64:96:30:ef:4a:8a:96:86:ce:f4:c7:be:10:24:8e:2b:60:9e:f3:59:53

Issuer
string (read-only)
Default: ""

The issuer of the certificate. This field contains a string representation of the name of the issuing authority for the certificate.

PrivateKey
string (read-only)
Default: ""

The private key of the certificate (if available). The key is provided as PEM/Base64-encoded data.

Note: The PrivateKey may be available but not exportable. In this case, PrivateKey returns an empty string.

PrivateKeyAvailable
bool (read-only)
Default: False

Whether a PrivateKey is available for the selected certificate. If PrivateKeyAvailable is True, the certificate may be used for authentication purposes (e.g., server authentication).

PrivateKeyContainer
string (read-only)
Default: ""

The name of the PrivateKey container for the certificate (if available). This functionality is available only on Windows platforms.

PublicKey
string (read-only)
Default: ""

The public key of the certificate. The key is provided as PEM/Base64-encoded data.

PublicKeyAlgorithm
string (read-only)
Default: ""

The textual description of the certificate's public key algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_DH") or an object identifier (OID) string representing the algorithm.

PublicKeyLength
int (read-only)
Default: 0

The length of the certificate's public key (in bits). Common values are 512, 1024, and 2048.

SerialNumber
string (read-only)
Default: ""

The serial number of the certificate encoded as a string. The number is encoded as a series of hexadecimal digits, with each pair representing a byte of the serial number.

SignatureAlgorithm
string (read-only)
Default: ""

The text description of the certificate's signature algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_MD5RSA") or an object identifier (OID) string representing the algorithm.

Store
string
Default: "MY"

The name of the certificate store for the client certificate.

The StoreType field denotes the type of the certificate store specified by Store. If the store is password-protected, specify the password in StorePassword.

Store is used in conjunction with the Subject field to specify client certificates. If Store has a value, and Subject or Encoded is set, a search for a certificate is initiated. Please see the Subject field for details.

Designations of certificate stores are platform dependent.

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


MY	A certificate store holding personal certificates with their associated private keys.
CA	Certifying authority certificates.
ROOT	Root certificates.

When the certificate store type is cstPFXFile, this property must be set to the name of the file. When the type is cstPFXBlob, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

StoreB
byte []
Default: "MY"

The name of the certificate store for the client certificate.

The StoreType field denotes the type of the certificate store specified by Store. If the store is password-protected, specify the password in StorePassword.

Designations of certificate stores are platform dependent.

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


MY	A certificate store holding personal certificates with their associated private keys.
CA	Certifying authority certificates.
ROOT	Root certificates.

StorePassword
string
Default: ""

If the type of certificate store requires a password, this field is used to specify the password needed to open the certificate store.

StoreType
CertStoreTypes
Default: 0

The type of certificate store for this certificate.

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:


0 (cstUser - default)	For Windows, this specifies that the certificate store is a certificate store owned by the current user. Note: This store type is not available in Java.
1 (cstMachine)	For Windows, this specifies that the certificate store is a machine store. Note: This store type is not available in Java.
2 (cstPFXFile)	The certificate store is the name of a PFX (PKCS#12) file containing certificates.
3 (cstPFXBlob)	The certificate store is a string (binary or Base64-encoded) representing a certificate store in PFX (PKCS#12) format.
4 (cstJKSFile)	The certificate store is the name of a Java Key Store (JKS) file containing certificates. Note: This store type is only available in Java.
5 (cstJKSBlob)	The certificate store is a string (binary or Base64-encoded) representing a certificate store in Java Key Store (JKS) format. Note: This store type is only available in Java.
6 (cstPEMKeyFile)	The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate.
7 (cstPEMKeyBlob)	The certificate store is a string (binary or Base64-encoded) that contains a private key and an optional certificate.
8 (cstPublicKeyFile)	The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate.
9 (cstPublicKeyBlob)	The certificate store is a string (binary or Base64-encoded) that contains a PEM- or DER-encoded public key certificate.
10 (cstSSHPublicKeyBlob)	The certificate store is a string (binary or Base64-encoded) that contains an SSH-style public key.
11 (cstP7BFile)	The certificate store is the name of a PKCS#7 file containing certificates.
12 (cstP7BBlob)	The certificate store is a string (binary) representing a certificate store in PKCS#7 format.
13 (cstSSHPublicKeyFile)	The certificate store is the name of a file that contains an SSH-style public key.
14 (cstPPKFile)	The certificate store is the name of a file that contains a PPK (PuTTY Private Key).
15 (cstPPKBlob)	The certificate store is a string (binary) that contains a PPK (PuTTY Private Key).
16 (cstXMLFile)	The certificate store is the name of a file that contains a certificate in XML format.
17 (cstXMLBlob)	The certificate store is a string that contains a certificate in XML format.
18 (cstJWKFile)	The certificate store is the name of a file that contains a JWK (JSON Web Key).
19 (cstJWKBlob)	The certificate store is a string that contains a JWK (JSON Web Key).
21 (cstBCFKSFile)	The certificate store is the name of a file that contains a BCFKS (Bouncy Castle FIPS Key Store). Note: This store type is only available in Java and .NET.
22 (cstBCFKSBlob)	The certificate store is a string (binary or Base64-encoded) representing a certificate store in BCFKS (Bouncy Castle FIPS Key Store) format. Note: This store type is only available in Java and .NET.
23 (cstPKCS11)	The certificate is present on a physical security key accessible via a PKCS#11 interface. To use a security key, the necessary data must first be collected using the CertMgr component. The ListStoreCertificates method may be called after setting CertStoreType to `cstPKCS11`, CertStorePassword to the PIN, and CertStore to the full path of the PKCS#11 DLL. The certificate information returned in the CertList event's `CertEncoded` parameter may be saved for later use. When using a certificate, pass the previously saved security key information as the Store and set StorePassword to the PIN. Code Example. SSH Authentication with Security Key: `certmgr.CertStoreType = CertStoreTypes.cstPKCS11; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; //PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22);`
99 (cstAuto)	The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically.

SubjectAltNames
string (read-only)
Default: ""

Comma-separated lists of alternative subject names for the certificate.

ThumbprintMD5
string (read-only)
Default: ""

The MD5 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

ThumbprintSHA1
string (read-only)
Default: ""

The SHA-1 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

ThumbprintSHA256
string (read-only)
Default: ""

The SHA-256 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

Usage
string (read-only)
Default: ""

The text description of UsageFlags.

This value will be one or more of the following strings and will be separated by commas:

Digital Signature
Non-Repudiation
Key Encipherment
Data Encipherment
Key Agreement
Certificate Signing
CRL Signing
Encipher Only

If the provider is OpenSSL, the value is a comma-separated list of X.509 certificate extension names.

UsageFlags
int (read-only)
Default: 0

The flags that show intended use for the certificate. The value of UsageFlags is a combination of the following flags:


0x80	Digital Signature
0x40	Non-Repudiation
0x20	Key Encipherment
0x10	Data Encipherment
0x08	Key Agreement
0x04	Certificate Signing
0x02	CRL Signing
0x01	Encipher Only

Please see the Usage field for a text representation of UsageFlags.

This functionality currently is not available when the provider is OpenSSL.

Version
string (read-only)
Default: ""

The certificate's version number. The possible values are the strings "V1", "V2", and "V3".

Subject
string
Default: ""

The subject of the certificate used for client authentication.

This field will be populated with the full subject of the loaded certificate. When loading a certificate, the subject is used to locate the certificate in the store.

If an exact match is not found, the store is searched for subjects containing the value of the property.

If a match is still not found, the property is set to an empty string, and no certificate is selected.

The special value "*" picks a random certificate in the certificate 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 as follows:


Field	Meaning
CN	Common Name. This is commonly a hostname like www.server.com.
O	Organization
OU	Organizational Unit
L	Locality
S	State
C	Country
E	Email Address

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

Encoded
string
Default: ""

The certificate (PEM/Base64 encoded). This field is used to assign a specific certificate. The Store and Subject fields also may be used to specify a certificate.

When Encoded is set, a search is initiated in the current Store for the private key of the certificate. If the key is found, Subject is updated to reflect the full subject of the selected certificate; otherwise, Subject is set to an empty string.

EncodedB
byte []
Default: ""

The certificate (PEM/Base64 encoded). This field is used to assign a specific certificate. The Store and Subject fields also may be used to specify a certificate.

Constructors

C#
VB.NET

public Certificate();

Public Certificate()

Creates a instance whose properties can be set. This is useful for use with 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 X.509 public key.

C#
VB.NET

public Certificate(byte[] encoded);

Public Certificate(ByVal Encoded As Byte())

Parses Encoded as an X.509 public key.

C#
VB.NET

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

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

StoreType identifies the type of certificate store to use. See 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 X.509 certificate's subject Distinguished Name (DN). The Subject parameter can also take an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load in a "Thumbprint=value" format.

C#
VB.NET

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

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

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 CryptoAPI option. The default value is True (the key is persisted). "Thumbprint" - an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load. When specified, this value is used to select the certificate in the store. This is applicable to the 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.

C#
VB.NET

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

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

After the store has been successfully opened, the component will load Encoded as an X.509 certificate and search the opened store for a corresponding private key.

C#
VB.NET

public Certificate(CertStoreTypes storeType, byte[] store, string storePassword, string subject);

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

StoreType identifies the type of certificate store to use. See for descriptions of the different certificate stores. Store is a byte array containing the certificate data. StorePassword is the password used to protect the store.

C#
VB.NET

public Certificate(CertStoreTypes storeType, byte[] store, string storePassword, string subject, string configurationString);

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

C#
VB.NET

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

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

After the store has been successfully opened, the component will load Encoded as an X.509 certificate and search the opened store for a corresponding private key.

Config Settings (DTLSClient Component)

The component accepts one or more of the following configuration settings. Configuration 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.

DTLSClient Config Settings

KeepAliveInterval: The retry interval, in seconds, to be used when a HeartbeatRequest is sent and no response is received.

This configuration specifies the retry interval, in seconds, to be used when a HeartbeatRequest message is sent and no response is received. HeartbeatRequest messages are only sent if the Heartbeat Extension is supported by the remote host.

The component will send a HeartbeatRequest message after a specified period of inactivity, defined by KeepAliveTime. This value specifies the interval at which the component sends successive HeartbeatRequest messages, assuming no response is received from the remote host (HeartbeatResponse). By default, this value is 2 seconds and will only apply if KeepAlive is true.

KeepAliveMode: Specifies the Heartbeat (or keep-alive) mode to be used by the component.

This configuration specifies the Heartbeat (or keep-alive) mode to be used by the component, as defined in RFC 6520. When KeepAlive is true, the following values are applicable:


1	peer_allowed_to_send (default)
2	peer_not_allowed_to_send

When set to 1 (peer_allowed_to_send), the component can both a) send HeartbeatRequest messages and b) receive and respond to HeartbeatRequest messages.

When set to 2 (peer_not_allowed_to_send), the component will only be capable of sending HeartbeatRequests.

Note, if KeepAlive is false, Heartbeat functionality will be disabled. The component will not be capable of sending or handling HeartbeatRequest messages.

KeepAliveTime: The inactivity time, in seconds, before a HeartbeatRequest is sent.

This configuration specifies the inactivity time, in seconds, before sending a HeartbeatRequest message. HeartbeatRequest messages are only sent if the Heartbeat Extension is supported by the remote host.

If the connection is inactive for the specified time, the component will send a HeartbeatRequest message to the remote host. If no response is received, the component will continue sending Heartbeats every KeepAliveInterval seconds. By default, this value is 60 seconds and will only apply if KeepAlive is true.

LogLevel: This configuration controls the level of detail that is logged through the Log event.

This configuration controls the level of detail that is logged through the Log event. Possible values are as follows:


0 (None)	No events are logged.
1 (Info - default)	Informational events are logged.
2 (Verbose)	Detailed data are logged.
3 (Debug)	Debug data are logged.

UDP Config Settings

CaptureIPPacketInfo: Used to capture the packet information.

If this configuration setting is set to True, the component will capture the IP packet information.

The default value for this setting is False.

Note: This setting is available only in Windows.

DelayHostResolution: Whether the hostname is resolved when RemoteHost is set.

This configuration setting specifies whether a hostname is resolved immediately when RemoteHost is set. If true the component will resolve the hostname and the IP address will be present in the RemoteHost property. If false, the hostname is not resolved until needed by the component when a method to connect or send data is called. If desired, ResolveRemoteHost may be called to manually resolve the value in RemoteHost at any time.

The default value is false for the default library and true for the async library.

DestinationAddress: Used to get the destination address from the packet information.

If CaptureIPPacketInfo is set to True, then this will be populated with the packet's destination address when a packet is received. This information will be accessible in the DataIn event.

Note: This setting is available only in Windows.

DontFragment: Used to set the Don't Fragment flag of outgoing packets.

When this configuration setting is set to True, packets sent by the component will have the Don't Fragment flag set. The default value is False.

LocalHost: The name of the local host through which connections are initiated or accepted.

The LocalHost setting 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 multihomed 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 setting 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 multihomed hosts (machines with more than one IP interface).

LocalPort: The port in the local host where the component binds.

This configuration setting must be set before a connection is attempted. It instructs the component to bind to a specific port (or communication endpoint) in the local machine.

Setting this to 0 (default) enables the system to choose a port at random. The chosen port will be shown by LocalPort after the connection is established.

LocalPort cannot be changed once a connection is made. Any attempt to set this when a connection is active will generate an error.

This configuration setting is useful when trying to connect to services that require a trusted port on the client side. An example is the remote shell (rsh) service in UNIX systems.

MaxPacketSize: The maximum length of the packets that can be received.

This configuration setting specifies the maximum size of the datagrams that the component will accept without truncation.

QOSDSCPValue: Used to specify an arbitrary QOS/DSCP setting (optional).

To use this configuration setting, UseConnection must be True. This option allows you to specify an arbitrary DiffServ Code Point (DSCP) value between 0 and 63. The default is 0. When set to the default value, the component will not set a DSCP value.

Note: This setting uses the qWAVE API and is available only on Windows 7, Windows Server 2008 R2, and later.

QOSTrafficType: Used to specify QOS/DSCP settings (optional).

To use this configuration setting, UseConnection must be True. You may specify either the text or integer values: BestEffort (0), Background (1), ExcellentEffort (2), AudioVideo (3), Voice (4), and Control (5).

Note: This setting uses the qWAVE API and is available only on Windows Vista and Windows Server 2008 or above.

Note: QOSTrafficType must be set before setting Active to True.

ShareLocalPort: If set to True, allows more than one instance of the component to be active on the same local port.

This option must be set before the component is activated through the Active property or it will have no effect.

The default value for this setting is False.

UseConnection: Determines whether to use a connected socket.

UseConnection specifies whether or not the component should use a connected socket. The connection is defined as an association in between the local address/port and the remote address/port. As such, this is not a connection in the traditional Transmission Control Protocol (TCP) sense. It means only that the component will send and receive data to and from the specified destination.

The default value for this setting is False.

UseIPv6: Whether or not to use IPv6.

By default, the component expects an IPv4 address for local and remote host properties and will create an IPv4 socket. To use IPv6 instead, set this to True.

Socket Config Settings

AbsoluteTimeout: Determines whether timeouts are inactivity timeouts or absolute timeouts.

If AbsoluteTimeout is set to True, any method that does not complete within Timeout seconds will be aborted. By default, AbsoluteTimeout is False, and the timeout is an inactivity timeout.

Note: This option is not valid for User Datagram Protocol (UDP) ports.

FirewallData: Used to send extra data to the firewall.

When the firewall is a tunneling proxy, use this property to send custom (additional) headers to the firewall (e.g., headers for custom authentication schemes).

InBufferSize: The size in bytes of the incoming queue of the socket.

This is the size of an internal queue in the Transmission Control Protocol (TCP)/IP stack. You can increase or decrease its size depending on the amount of data that you will be receiving. In some cases, increasing the value of the InBufferSize setting can provide significant improvements in performance.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the InBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

OutBufferSize: The size in bytes of the outgoing queue of the socket.

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be sending. In some cases, increasing the value of the OutBufferSize setting can provide significant improvements in performance.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the OutBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

SSL Config Settings

CACertFilePaths: The paths to CA certificate files when using Mono on Unix/Linux.

This configuration setting specifies the paths on disk to certificate authority (CA) certificate files when using Mono on Unix/Linux. It is not applicable in any other circumstances.

The value is formatted as a list of paths separated by semicolons. The component will check for the existence of each file in the order specified. When a file is found, the CA certificates within the file will be loaded and used to determine the validity of server or client certificates.

The default value is as follows:

/etc/ssl/ca-bundle.pem;/etc/pki/tls/certs/ca-bundle.crt;/etc/ssl/certs/ca-certificates.crt;/etc/pki/tls/cacert.pem

LogSSLPackets: Controls whether SSL packets are logged.

This configuration setting controls whether SSL packets should be logged. By default, this configuration setting is False, as it is useful only for debugging purposes.

When enabled, SSL packet logs are output using the SSLStatus event, which will fire each time a SSL packet is sent or received.

ReuseSSLSession: Determines if the SSL session is reused.

If set to True, the component will reuse the context if and only if the following criteria are met:

The target host name is the same.
The system cache entry has not expired (default timeout is 10 hours).
The application process that calls the function is the same.
The logon session is the same.
The instance of the component is the same.

SSLCACerts: A newline separated list of CA certificates to be included when performing an SSL handshake.

When SSLProvider is set to Internal, this configuration setting specifies one or more CA certificates to be included with the SSLCert property. Some servers or clients require the entire chain, including CA certificates, to be presented when performing SSL authentication. The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance:

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

SSLCheckCRL: Whether to check the Certificate Revocation List for the server certificate.

This configuration setting specifies whether the component will check the Certificate Revocation List (CRL) specified by the server certificate. If set to 1 or 2, the component will first obtain the list of CRL URLs from the server certificate's CRL distribution points extension. The component will then make HTTP requests to each CRL endpoint to check the validity of the server's certificate. If the certificate has been revoked or any other issues are found during validation the component throws an exception.

When set to 0 (default), the CRL check will not be performed by the component. When set to 1, it will attempt to perform the CRL check, but it will continue without an error if the server's certificate does not support CRL. When set to 2, it will perform the CRL check and will throw an error if CRL is not supported.

This configuration setting is supported only in the Java, C#, and C++ editions. In the C++ edition, it is supported only on Windows operating systems.

SSLCheckOCSP: Whether to use OCSP to check the status of the server certificate.

This configuration setting specifies whether the component will use OCSP to check the validity of the server certificate. If set to 1 or 2, the component will first obtain the Online Certificate Status Protocol (OCSP) URL from the server certificate's OCSP extension. The component will then locate the issuing certificate and make an HTTP request to the OCSP endpoint to check the validity of the server's certificate. If the certificate has been revoked or any other issues are found during validation, the component throws an exception.

When set to 0 (default), the component will not perform an OCSP check. When set to 1, it will attempt to perform the OCSP check, but it will continue without an error if the server's certificate does not support OCSP. When set to 2, it will perform the OCSP check and will throw an error if OCSP is not supported.

This configuration setting is supported only in the Java, C#, and C++ editions. In the C++ edition, it is supported only on Windows operating systems.

SSLCipherStrength: The minimum cipher strength used for bulk encryption.

This minimum cipher strength is largely dependent on the security modules installed on the system. If the cipher strength specified is not supported, an error will be returned when connections are initiated.

Note: This configuration setting contains the minimum cipher strength requested from the security library. The actual cipher strength used for the connection is shown by the SSLStatus event.

Use this configuration setting with caution. Requesting a lower cipher strength than necessary could potentially cause serious security vulnerabilities in your application.

When the provider is OpenSSL, SSLCipherStrength is currently not supported. This functionality is instead made available through the OpenSSLCipherList configuration setting.

SSLClientCACerts: A newline separated list of CA certificates to use during SSL client certificate validation.

This configuration setting is only applicable to server components (e.g., TCPServer) see SSLServerCACerts for client components (e.g., TCPClient). This setting can be used to optionally specify one or more CA certificates to be used when verifying the client certificate that is presented by the client during the SSL handshake when SSLAuthenticateClients is enabled. When verifying the client's certificate, the certificates trusted by the system will be used as part of the verification process. If the client's CA certificates are not installed to the trusted system store, they may be specified here so they are included when performing the verification process. This configuration setting should be set only if the client's CA certificates are not already trusted on the system and cannot be installed to the trusted system store.

The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance:

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

SSLEnabledCipherSuites: Specifies the cipher suites to be used during TLS negotiation.

This configuration is used to specify the cipher suites to be used during TLS negotiation.

By default, the enabled cipher suites will include all available ciphers ("*").

The special value "*" means that the component will pick all of the supported cipher suites. If SSLEnabledCipherSuites is set to any other value, only the specified cipher suites will be considered.

Multiple cipher suites are separated by semicolons. For example:

obj.config("SSLEnabledCipherSuites=*"); obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA"); obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA;TLS_ECDH_RSA_WITH_AES_128_CBC_SHA");

Possible cipher suites include the following:

TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384
TLS_RSA_WITH_AES_256_GCM_SHA384
TLS_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256
TLS_DHE_DSS_WITH_AES_256_GCM_SHA384
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
TLS_DHE_DSS_WITH_AES_128_GCM_SHA256
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384
TLS_DHE_DSS_WITH_AES_256_CBC_SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
TLS_RSA_WITH_AES_128_CBC_SHA256
TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256
TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256
TLS_DHE_DSS_WITH_AES_128_CBC_SHA256
TLS_RSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA
TLS_DHE_RSA_WITH_AES_256_CBC_SHA
TLS_ECDH_RSA_WITH_AES_256_CBC_SHA
TLS_DHE_DSS_WITH_AES_256_CBC_SHA
TLS_RSA_WITH_AES_128_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA
TLS_ECDH_RSA_WITH_AES_128_CBC_SHA
TLS_DHE_RSA_WITH_AES_128_CBC_SHA
TLS_DHE_DSS_WITH_AES_128_CBC_SHA
TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA
TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA
TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA
TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA
TLS_RSA_WITH_3DES_EDE_CBC_SHA
TLS_RSA_WITH_DES_CBC_SHA
TLS_DHE_RSA_WITH_DES_CBC_SHA
TLS_DHE_DSS_WITH_DES_CBC_SHA
TLS_RSA_WITH_RC4_128_MD5
TLS_RSA_WITH_RC4_128_SHA

SSLEnabledProtocols: Used to enable/disable the supported security protocols.

This configuration setting is used to enable or disable the supported security protocols.

The default value is 3072. To specify a combination of enabled protocol versions set this config to the binary OR of one or more of the following values:


TLS1.2	3072 (Hex C00) (Default - Client and Server)

SSLEnableRenegotiation: Whether the renegotiation_info SSL extension is supported.

This configuration setting specifies whether the renegotiation_info SSL extension will be used in the request when using the internal security API. This configuration setting is false by default, but it can be set to true to enable the extension.

This configuration setting is applicable only when SSLProvider is set to Internal.

SSLKeyLogFile: The location of a file where per-session secrets are written for debugging purposes.

This configuration setting optionally specifies the full path to a file on disk where per-session secrets are stored for debugging purposes.

When set, the component will save the session secrets in the same format as the SSLKEYLOGFILE environment variable functionality used by most major browsers and tools, such as Chrome, Firefox, and cURL. This file can then be used in tools such as Wireshark to decrypt TLS traffic for debugging purposes. When writing to this file, the component will only append, it will not overwrite previous values.

Note: This configuration setting is applicable only when SSLProvider is set to Internal.

SSLNegotiatedCipher: Returns the negotiated cipher suite.

This configuration setting returns the cipher suite negotiated during the SSL handshake.

Note: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: server.Config("SSLNegotiatedCipher[connId]");

SSLNegotiatedCipherStrength: Returns the negotiated cipher suite strength.

This configuration setting returns the strength of the cipher suite negotiated during the SSL handshake.

Note: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: server.Config("SSLNegotiatedCipherStrength[connId]");

SSLNegotiatedCipherSuite: Returns the negotiated cipher suite.

This configuration setting returns the cipher suite negotiated during the SSL handshake represented as a single string.

SSLNegotiatedKeyExchange: Returns the negotiated key exchange algorithm.

This configuration setting returns the key exchange algorithm negotiated during the SSL handshake.

SSLNegotiatedKeyExchangeStrength: Returns the negotiated key exchange algorithm strength.

This configuration setting returns the strength of the key exchange algorithm negotiated during the SSL handshake.

SSLNegotiatedVersion: Returns the negotiated protocol version.

This configuration setting returns the protocol version negotiated during the SSL handshake.

Note: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: server.Config("SSLNegotiatedVersion[connId]");

SSLSecurityFlags: Flags that control certificate verification.

The following flags are defined (specified in hexadecimal notation). They can be ORed together to exclude multiple conditions:


0x00000001	Ignore time validity status of certificate.
0x00000002	Ignore time validity status of CTL.
0x00000004	Ignore non-nested certificate times.
0x00000010	Allow unknown certificate authority.
0x00000020	Ignore wrong certificate usage.
0x00000100	Ignore unknown certificate revocation status.
0x00000200	Ignore unknown CTL signer revocation status.
0x00000400	Ignore unknown certificate authority revocation status.
0x00000800	Ignore unknown root revocation status.
0x00008000	Allow test root certificate.
0x00004000	Trust test root certificate.
0x80000000	Ignore non-matching CN (certificate CN non-matching server name).

This functionality is currently not available in Java or when the provider is OpenSSL.

SSLServerCACerts: A newline separated list of CA certificates to use during SSL server certificate validation.

This configuration setting is only used by client components (e.g., TCPClient) see SSLClientCACerts for server components (e.g., TCPServer). This configuration setting can be used to optionally specify one or more CA certificates to be used when connecting to the server and verifying the server certificate. When verifying the server's certificate, the certificates trusted by the system will be used as part of the verification process. If the server's CA certificates are not installed to the trusted system store, they may be specified here so they are included when performing the verification process. This configuration setting should be set only if the server's CA certificates are not already trusted on the system and cannot be installed to the trusted system store.

The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance:

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

TLS12SignatureAlgorithms: Defines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal.

This configuration setting specifies the allowed server certificate signature algorithms when SSLProvider is set to Internal and SSLEnabledProtocols is set to allow TLS 1.2.

When specified the component will verify that the server certificate signature algorithm is among the values specified in this configuration setting. If the server certificate signature algorithm is unsupported, the component throws an exception.

The format of this value is a comma-separated list of hash-signature combinations. For instance: component.SSLProvider = TCPClientSSLProviders.sslpInternal; component.Config("SSLEnabledProtocols=3072"); //TLS 1.2 component.Config("TLS12SignatureAlgorithms=sha256-rsa,sha256-dsa,sha1-rsa,sha1-dsa"); The default value for this configuration setting is sha512-ecdsa,sha512-rsa,sha512-dsa,sha384-ecdsa,sha384-rsa,sha384-dsa,sha256-ecdsa,sha256-rsa,sha256-dsa,sha224-ecdsa,sha224-rsa,sha224-dsa,sha1-ecdsa,sha1-rsa,sha1-dsa.

To not restrict the server's certificate signature algorithm, specify an empty string as the value for this configuration setting, which will cause the signature_algorithms TLS 1.2 extension to not be sent.

TLS12SupportedGroups: The supported groups for ECC.

This configuration setting specifies a comma-separated list of named groups used in TLS 1.2 for ECC.

The default value is ecdhe_secp256r1,ecdhe_secp384r1,ecdhe_secp521r1.

When using TLS 1.2 and SSLProvider is set to Internal, the values refer to the supported groups for ECC. The following values are supported:

"ecdhe_secp256r1" (default)
"ecdhe_secp384r1" (default)
"ecdhe_secp521r1" (default)

Base Config Settings

BuildInfo: Information about the product's build.

When queried, this setting will return a string containing information about the product's build.

GUIAvailable: Whether or not a message loop is available for processing events.

In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The component will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation.

In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GUIAvailable to false will ensure that the component does not attempt to process external events.

LicenseInfo: Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a component is using. It will return the following information:

Product: The product the license is for.
Product Key: The key the license was generated from.
License Source: Where the license was found (e.g., RuntimeLicense, License File).
License Type: The type of license installed (e.g., Royalty Free, Single Server).
Last Valid Build: The last valid build number for which the license will work.

MaskSensitiveData: Whether sensitive data is masked in log messages.

In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to true to mask sensitive data. The default is true.

This setting only works on these components: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.

UseInternalSecurityAPI: Whether or not to use the system security libraries or an internal implementation.

When set to false, the component will use the system security libraries by default to perform cryptographic functions where applicable. In this case, calls to unmanaged code will be made. In certain environments, this is not desirable. To use a completely managed security implementation, set this setting to true.

Setting this configuration setting to true tells the component to use the internal implementation instead of using the system security libraries.

On Windows, this setting is set to false by default. On Linux/macOS, this setting is set to true by default.

If using the .NET Standard Library, this setting will be true on all platforms. The .NET Standard library does not support using the system security libraries.

Note: This setting is static. The value set is applicable to all components used in the application.

When this value is set, the product's system dynamic link library (DLL) is no longer required as a reference, as all unmanaged code is stored in that file.

Trappable Errors (DTLSClient Component)

DTLSClient Errors

400	Invalid datagram received. See the error description for further details.
401	Invalid DTLS flow. See the error description for further details.
402	Not supported. See the error description for further details.
403	DTLS handshake error. See the error description for further details.
404	Invalid certificate provided. See the error description for further details.
405	Fatal alert. See the error description for further details.