DTLSClient Component

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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.

For KeepAlive, DoEvents must be called frequently to ensure the component sends keep-alive (or Heartbeat) packets to existing connections 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.

AcceptDataThis property indicates whether data reception is currently enabled.
ConnectedThis property indicates whether the component is connected.
KeepAliveWhen True, keep-alive functionality is enabled via the DTLS Heartbeat Extension.
LocalHostThis property includes the name of the local host or user-assigned IP interface through which connections are initiated or accepted.
LocalPortThis property includes the User Datagram Protocol (UDP) port in the local host where UDP binds.
RemoteHostThis property includes the address of the remote host. Domain names are resolved to IP addresses.
RemotePortThis property specifies the User Datagram Protocol (UDP) port in the remote host.
SSLAcceptServerCertThis property instructs the component to unconditionally accept the server certificate that matches the supplied certificate.
SSLCertThis property includes the certificate to be used during Secure Sockets Layer (SSL) negotiation.
TimeoutThis 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.

ConfigThis method sets or retrieves a configuration setting.
ConnectThis method connects to a remote host.
DisconnectThis method disconnects from the remote host.
DoEventsThis method processes events from the internal message queue.
PauseDataThis method pauses data reception.
ProcessDataThis method reenables data reception after a call to PauseData
ResetThis method will reset the component.
SendBytesThis method sends binary data to the remote host.
SendTextThis 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.

ConnectedThis event is fired immediately after a connection completes (or fails).
DataInThis event is fired when data are received.
DisconnectedThis event is fired when a connection is closed.
ErrorThis event is fired for information about errors during data delivery.
LogThis event fires once for each log message.
SSLServerAuthenticationThis event is fired after the server presents its certificate to the client.
SSLStatusThis event shows the progress of the secure connection.

Config Settings


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

EnabledCipherSuitesSpecifies the cipher suites to be used during TLS negotiation.
KeepAliveIntervalThe retry interval, in seconds, to be used when a HeartbeatRequest is sent and no response is received.
KeepAliveModeSpecifies the Heartbeat (or keep-alive) mode to be used by the component.
KeepAliveTimeThe inactivity time, in seconds, before a HeartbeatRequest is sent.
LogLevelThis configuration controls the level of detail that is logged through the Log event.
LogSSLPacketsControls whether SSL packets are logged.
CaptureIPPacketInfoUsed to capture the packet information.
DelayHostResolutionWhether the hostname is resolved when RemoteHost is set.
DestinationAddressUsed to get the destination address from the packet information.
DontFragmentUsed to set the Don't Fragment flag of outgoing packets.
LocalHostThe name of the local host through which connections are initiated or accepted.
LocalPortThe port in the local host where the component binds.
MaxPacketSizeThe maximum length of the packets that can be received.
QOSDSCPValueUsed to specify an arbitrary QOS/DSCP setting (optional).
QOSTrafficTypeUsed to specify QOS/DSCP settings (optional).
ShareLocalPortIf set to True, allows more than one instance of the component to be active on the same local port.
UseConnectionDetermines whether to use a connected socket.
UseIPv6Whether or not to use IPv6.
AbsoluteTimeoutDetermines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallDataUsed to send extra data to the firewall.
InBufferSizeThe size in bytes of the incoming queue of the socket.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
BuildInfoInformation about the product's build.
GUIAvailableTells the component whether or not a message loop is available for processing events.
LicenseInfoInformation about the current license.
MaskSensitiveWhether sensitive data is masked in log messages.
UseInternalSecurityAPITells the component 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.

Syntax

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

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

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)

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

Syntax

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 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 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

public int LocalPort { get; set; }
Public Property LocalPort As Integer

Default Value

0

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

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

public int RemotePort { get; set; }
Public Property RemotePort As Integer

Default Value

0

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)

This property instructs the component to unconditionally accept the server certificate that matches the supplied certificate.

Syntax

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)

This property includes the certificate to be used during Secure Sockets Layer (SSL) negotiation.

Syntax

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.

Timeout Property (DTLSClient Component)

This property specifies a timeout when connecting to a server.

Syntax

public int Timeout { get; set; }
Public Property Timeout As Integer

Default Value

60

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)

This method sets or retrieves a configuration setting.

Syntax

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

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

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

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

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

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

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

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

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

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

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

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)

This event is fired for information about errors during data delivery.

Syntax

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.

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 (DTLSClient Component)

This event fires once for each log message.

Syntax

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

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)

This event shows the progress of the secure connection.

Syntax

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.

Fields

EffectiveDate
string (read-only)

Default: ""

This is the date on which this certificate becomes valid. Before this date, it is not valid. The following example illustrates the format of an encoded date:

23-Jan-2000 15:00:00.

Encoded
string

Default: ""

This is 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: ""

This is 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.

ExpirationDate
string (read-only)

Default: ""

This is the date the certificate expires. After this date, the certificate will no longer be valid. The following example illustrates the format of an encoded date:

23-Jan-2001 15:00:00.

ExtendedKeyUsage
string (read-only)

Default: ""

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

Fingerprint
string (read-only)

Default: ""

This is 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: ""

This is 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: ""

This is 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: ""

This is 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: ""

This is 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

This field shows 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: ""

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

PublicKey
string (read-only)

Default: ""

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

PublicKeyAlgorithm
string (read-only)

Default: ""

This field contains 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

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

SerialNumber
string (read-only)

Default: ""

This is 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 field contains 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"

This is 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:

MYA certificate store holding personal certificates with their associated private keys.
CACertifying authority certificates.
ROOTRoot certificates.

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).

StoreB
byte []

Default: "MY"

This is 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:

MYA certificate store holding personal certificates with their associated private keys.
CACertifying authority certificates.
ROOTRoot certificates.

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).

StorePassword
string

Default: ""

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

StoreType
CertStoreTypes

Default: 0

This is 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 (PKCS12) file containing certificates.
3 (cstPFXBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in PFX (PKCS12) 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 PKCS7 file containing certificates.
12 (cstP7BBlob)The certificate store is a string (binary) representing a certificate store in PKCS7 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 PKCS11 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 PKCS11 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.

Subject
string

Default: ""

This is 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, or E=support@nsoftware.com". Common fields and their meanings are as follows:

FieldMeaning
CNCommon Name. This is commonly a host name like www.server.com.
OOrganization
OUOrganizational Unit
LLocality
SState
CCountry
EEmail Address

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

SubjectAltNames
string (read-only)

Default: ""

This field contains comma-separated lists of alternative subject names for the certificate.

ThumbprintMD5
string (read-only)

Default: ""

This field contains 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: ""

This field contains 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: ""

This field contains 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: ""

This field contains the text description of UsageFlags.

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

  • Digital Signatures
  • Key Authentication
  • Key Encryption
  • Data Encryption
  • Key Agreement
  • Certificate Signing
  • Key Signing

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

UsageFlags
int (read-only)

Default: 0

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

0x80Digital Signatures
0x40Key Authentication (Non-Repudiation)
0x20Key Encryption
0x10Data Encryption
0x08Key Agreement
0x04Certificate Signing
0x02Key Signing

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: ""

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

Constructors

public Certificate();
Public Certificate()

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

public Certificate(string certificateFile);
Public Certificate(ByVal CertificateFile As String)

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

public Certificate(byte[] encoded);
Public Certificate(ByVal Encoded As Byte())

Parses CertificateData as an X509 public key.

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).

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).

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.

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).

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).

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.

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

EnabledCipherSuites:   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 EnabledCipherSuites 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

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 to remote host 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:

1peer_allowed_to_send (default)
2peer_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.

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.

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. The default value is false.

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.

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:   Tells the component 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.
MaskSensitive:   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:   Tells the component whether or not to use the system security libraries or an internal implementation.

When set to false, this 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.