DTLSServer Class

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The DTLSServer class provides server-side functionality for secure UDP communication utilizing the Datagram Transport Layer Security (DTLS) protocol.

Syntax

DTLSServer

Remarks

The DTLSServer class functions as a server that facilitates incoming DTLS connections and offers a convenient means of transmitting and receiving datagrams over the established, secure connections.

Getting Started

First, a valid certificate must be selected before the server can start listening for incoming connections. The certificate can be specified via the SSLCert* properties. Note the certificate must contain a private key.

After doing so, calling StartListening will cause the class to start listening for incoming connections. The class will listen on the interface defined by LocalHost and LocalPort, if specified. Otherwise, these values will be set by the class. If applicable, these values must be set before calling StartListening. For example:

//dtlsserver.LocalHost = "some_ip_address"; //dtlsserver.LocalPort = 1234; dtlsserver.SSLCert = new Certificate("/path/to/cert.pfx", CertStoreTypes.cstPFXFile, "cert_password", "cert_subject"); dtlsserver.StartListening(); Console.WriteLine("Listening on: " + dtlsserver.LocalHost + ":" + dtlsserver.LocalPort); while (dtlsserver.Listening) { dtlsserver.DoEvents(); }

Handling Incoming Connections

Once successfully listening, the class can now accept (or reject) incoming connections. The first indicator of an incoming connection will be through the ConnectionRequest event. Here, the connection's originating address and port can be queried. By default, the class will accept all incoming connections, but this behavior can be overridden within this event.

Assuming the connection is accepted, the DTLS handshake will proceed. Relevant handshake details will be reported by the SSLStatus event. By default, the client is not required to present a certificate to the server. To force this, the SSLAuthenticateClients property can be enabled. When enabled, the client's presented certificate will be available within the SSLClientAuthentication event, where the server can again choose to accept (or reject) incoming connections.

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.

After a successful connection, relevant connection-specific details will be available within the Connections collection. Each connection will be assigned a unique ConnectionId, which can be acquired for a given connection within the Connected event. For example:

dtlsserver.OnConnected += (o, e) => { if (e.StatusCode == 0) { Console.WriteLine("Successful connection from " + e.SourceAddr + ":" + e.SourcePort); Console.WriteLine("ConnectionId: " + e.ConnectionId); } else { Console.WriteLine("Connection failed from " + e.SourceAddr + ":" + e.SourcePort); Console.WriteLine("Error code: " + e.StatusCode); Console.WriteLine("Error description: " + e.Description); } }; dtlsserver.OnSSLClientAuthentication += (o, e) => { if (e.Accept) return; Console.Write("Client 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; }; dtlsserver.SSLCert = new Certificate("/path/to/cert.pfx", CertStoreTypes.cstPFXFile, "cert_password", "cert_subject"); dtlsserver.AuthenticateClients = true; dtlsserver.StartListening(); Console.WriteLine("Listening on: " + dtlsserver.LocalHost + ":" + dtlsserver.LocalPort); while (dtlsserver.Listening) { dtlsserver.DoEvents(); }

Sending and Receiving Data

The class can send data to individual connections, specified by the ConnectionId parameter, via the SendBytes and SendText methods.

While a connection is active, incoming data from a connection will be available within 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 a particular connection. Data reception can later be enabled via the ProcessData method. Note that if this reception is disabled for a connection, the connection may continue sending data, which will remain unprocessed by the class. In this case, the underlying socket buffer may be filled. This can result in possible data loss originating from this connection. Please use these methods with caution.

The complete process may look like the following:

dtlsserver.OnDataIn += (o, e) => { Console.WriteLine("Packet received from: " + e.ConnectionId); Console.WriteLine("Packet: " + e.Datagram); }; dtlsserver.SSLCert = new Certificate("/path/to/cert.pfx", CertStoreTypes.cstPFXFile, "cert_password", "cert_subject"); dtlsserver.StartListening(); Console.WriteLine("Listening on: " + dtlsserver.LocalHost + ":" + dtlsserver.LocalPort); ... ... ... // Broadcast data foreach (DTLSConnection c in dtlsserver.Connections.Values) { dtlsserver.SendText(c.ConnectionId, "Hello world!"); }

Removing Connections

To remove a connection, Disconnect must be called with the corresponding ConnectionId. In order to remove inactive connections, the DefaultIdleTimeout property can be set accordingly. By default, this property is set to 0, and idle connections are not removed automatically. When this property is set to a positive value, this will automatically remove connections that are idle for a specified amount of time.

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

Finally, once a connection ends, Disconnected will fire. In the case a connection ends and an error is encountered, the StatusCode and Description parameters will contain relevant details regarding the error. The connection will be removed from the Connections collection. For example:

dtlsserver.OnDisconnected += (o, e) => { if (e.StatusCode == 0) { Console.WriteLine("Connection removed: " + e.ConnectionId); } else { Console.WriteLine("Connection removed: " + e.ConnectionId); Console.WriteLine("Error code: " + e.StatusCode); Console.WriteLine("Error description: " + e.Description); } }; dtlsserver.DefaultIdleTimeout = 60; // Remove connections inactive for 60 seconds dtlsserver.StartListening(); Console.WriteLine("Listening on: " + dtlsserver.LocalHost + ":" + dtlsserver.LocalPort); while (dtlsserver.Listening) { dtlsserver.DoEvents(); }

Additional Information

To support DefaultIdleTimeout and KeepAlive functionality, it is important to note that DoEvents must be called regularly in both console and form-based applications.

For DefaultIdleTimeout, DoEvents must be called frequently to ensure that idle connections are handled and removed in a timely manner. For KeepAlive, DoEvents must be called frequently to ensure the class sends keep-alive (or Heartbeat) packets to existing connections in a timely manner.

In form-based applications, this does not apply if DefaultIdleTimeout is set to 0 and KeepAlive is False.

Property List

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

Method List

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

Event List

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

Config Settings

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

Connections Property (DTLSServer Class)

This property includes a collection of currently connected clients.

Syntax

• C++
• C
• Qt

IPWorksDTLSList<IPWorksDTLSDTLSConnection>* GetConnections();
int SetConnections(IPWorksDTLSList<IPWorksDTLSDTLSConnection>* val);

int ipworksdtls_dtlsserver_getconnectioncount(void* lpObj);
int ipworksdtls_dtlsserver_setconnectioncount(void* lpObj, int iConnectionCount);

int ipworksdtls_dtlsserver_getconnectionconnectionid(void* lpObj, int connectionid);

char* ipworksdtls_dtlsserver_getconnectionlocalhost(void* lpObj, int connectionid);

int ipworksdtls_dtlsserver_getconnectionlocalport(void* lpObj, int connectionid);

char* ipworksdtls_dtlsserver_getconnectionremotehost(void* lpObj, int connectionid);

int ipworksdtls_dtlsserver_getconnectionremoteport(void* lpObj, int connectionid);

int GetConnectionCount();
int SetConnectionCount(int iConnectionCount);

int GetConnectionConnectionId(int iConnectionId);

QString GetConnectionLocalHost(int iConnectionId);

int GetConnectionLocalPort(int iConnectionId);

QString GetConnectionRemoteHost(int iConnectionId);

int GetConnectionRemotePort(int iConnectionId);

Remarks

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

The collection is a hash-table type of collection, in which the ConnectionId string is used as the key to the desired connection. You may acquire the key for a given connection through the Connected event.

Example (Broadcasting Data)

foreach (DTLSConnection c in dtlsserver.Connections.Values) { dtlsserver.SendText(c.ConnectionId, "Hello world!"); }

This property is not available at design time.

Data Type

IPWorksDTLSDTLSConnection

DefaultIdleTimeout Property (DTLSServer Class)

This property includes the default idle timeout for inactive clients.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetDefaultIdleTimeout();
int SetDefaultIdleTimeout(int iDefaultIdleTimeout);

Unicode (Windows)
INT GetDefaultIdleTimeout();
INT SetDefaultIdleTimeout(INT iDefaultIdleTimeout);

int ipworksdtls_dtlsserver_getdefaultidletimeout(void* lpObj);
int ipworksdtls_dtlsserver_setdefaultidletimeout(void* lpObj, int iDefaultIdleTimeout);

int GetDefaultIdleTimeout();
int SetDefaultIdleTimeout(int iDefaultIdleTimeout);

Default Value

0

Remarks

This property specifies the idle timeout (in seconds) for clients. When set to a positive value, the class will disconnect idle clients after the specified timeout.

This applies only to clients that have not sent or received data within DefaultIdleTimeout seconds.

If set to 0 (default), no idle timeout is applied.

Note: DoEvents must be called for the class to check existing connections.

Data Type

Integer

KeepAlive Property (DTLSServer Class)

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

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetKeepAlive();
int SetKeepAlive(int bKeepAlive);

Unicode (Windows)
BOOL GetKeepAlive();
INT SetKeepAlive(BOOL bKeepAlive);

int ipworksdtls_dtlsserver_getkeepalive(void* lpObj);
int ipworksdtls_dtlsserver_setkeepalive(void* lpObj, int bKeepAlive);

bool GetKeepAlive();
int SetKeepAlive(bool bKeepAlive);

Default Value

FALSE

Remarks

This property enables keep-alive functionality for established connections via the DTLS Heartbeat Extension (RFC 6520). Enabling this option can prevent long connections 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.

Data Type

Boolean

Listening Property (DTLSServer Class)

This property indicates whether the class is listening for incoming connections on LocalPort.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetListening();

Unicode (Windows)
BOOL GetListening();

int ipworksdtls_dtlsserver_getlistening(void* lpObj);

bool GetListening();

Default Value

FALSE

Remarks

This property indicates whether the class is listening for connections on the port specified by the LocalPort property. Use the StartListening and StopListening methods to control whether the class is listening.

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

Data Type

Boolean

LocalHost Property (DTLSServer Class)

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

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetLocalHost();
int SetLocalHost(const char* lpszLocalHost);

Unicode (Windows)
LPWSTR GetLocalHost();
INT SetLocalHost(LPCWSTR lpszLocalHost);

char* ipworksdtls_dtlsserver_getlocalhost(void* lpObj);
int ipworksdtls_dtlsserver_setlocalhost(void* lpObj, const char* lpszLocalHost);

QString GetLocalHost();
int SetLocalHost(QString qsLocalHost);

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 class initiate connections (or accept in the case of server classs) only through that interface.

If the class 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.

Data Type

String

LocalPort Property (DTLSServer Class)

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

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetLocalPort();
int SetLocalPort(int iLocalPort);

Unicode (Windows)
INT GetLocalPort();
INT SetLocalPort(INT iLocalPort);

int ipworksdtls_dtlsserver_getlocalport(void* lpObj);
int ipworksdtls_dtlsserver_setlocalport(void* lpObj, int iLocalPort);

int GetLocalPort();
int SetLocalPort(int iLocalPort);

Default Value

0

Remarks

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

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

Data Type

Integer

SSLAuthenticateClients Property (DTLSServer Class)

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

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetSSLAuthenticateClients();
int SetSSLAuthenticateClients(int bSSLAuthenticateClients);

Unicode (Windows)
BOOL GetSSLAuthenticateClients();
INT SetSSLAuthenticateClients(BOOL bSSLAuthenticateClients);

int ipworksdtls_dtlsserver_getsslauthenticateclients(void* lpObj);
int ipworksdtls_dtlsserver_setsslauthenticateclients(void* lpObj, int bSSLAuthenticateClients);

bool GetSSLAuthenticateClients();
int SetSSLAuthenticateClients(bool bSSLAuthenticateClients);

Default Value

FALSE

Remarks

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

Data Type

Boolean

SSLCert Property (DTLSServer Class)

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

Syntax

• C++
• C
• Qt

IPWorksDTLSCertificate* GetSSLCert();
int SetSSLCert(IPWorksDTLSCertificate* val);

char* ipworksdtls_dtlsserver_getsslcerteffectivedate(void* lpObj);

int ipworksdtls_dtlsserver_getsslcertencoded(void* lpObj, char** lpSSLCertEncoded, int* lenSSLCertEncoded);
int ipworksdtls_dtlsserver_setsslcertencoded(void* lpObj, const char* lpSSLCertEncoded, int lenSSLCertEncoded);

char* ipworksdtls_dtlsserver_getsslcertexpirationdate(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertextendedkeyusage(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertfingerprint(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertfingerprintsha1(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertfingerprintsha256(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertissuer(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertprivatekey(void* lpObj);

int ipworksdtls_dtlsserver_getsslcertprivatekeyavailable(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertprivatekeycontainer(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertpublickey(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertpublickeyalgorithm(void* lpObj);

int ipworksdtls_dtlsserver_getsslcertpublickeylength(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertserialnumber(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertsignaturealgorithm(void* lpObj);

int ipworksdtls_dtlsserver_getsslcertstore(void* lpObj, char** lpSSLCertStore, int* lenSSLCertStore);
int ipworksdtls_dtlsserver_setsslcertstore(void* lpObj, const char* lpSSLCertStore, int lenSSLCertStore);

char* ipworksdtls_dtlsserver_getsslcertstorepassword(void* lpObj);
int ipworksdtls_dtlsserver_setsslcertstorepassword(void* lpObj, const char* lpszSSLCertStorePassword);

int ipworksdtls_dtlsserver_getsslcertstoretype(void* lpObj);
int ipworksdtls_dtlsserver_setsslcertstoretype(void* lpObj, int iSSLCertStoreType);

char* ipworksdtls_dtlsserver_getsslcertsubject(void* lpObj);
int ipworksdtls_dtlsserver_setsslcertsubject(void* lpObj, const char* lpszSSLCertSubject);

char* ipworksdtls_dtlsserver_getsslcertsubjectaltnames(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertthumbprintmd5(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertthumbprintsha1(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertthumbprintsha256(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertusage(void* lpObj);

int ipworksdtls_dtlsserver_getsslcertusageflags(void* lpObj);

char* ipworksdtls_dtlsserver_getsslcertversion(void* lpObj);

QString GetSSLCertEffectiveDate();

QByteArray GetSSLCertEncoded();
int SetSSLCertEncoded(QByteArray qbaSSLCertEncoded);

QString GetSSLCertExpirationDate();

QString GetSSLCertExtendedKeyUsage();

QString GetSSLCertFingerprint();

QString GetSSLCertFingerprintSHA1();

QString GetSSLCertFingerprintSHA256();

QString GetSSLCertIssuer();

QString GetSSLCertPrivateKey();

bool GetSSLCertPrivateKeyAvailable();

QString GetSSLCertPrivateKeyContainer();

QString GetSSLCertPublicKey();

QString GetSSLCertPublicKeyAlgorithm();

int GetSSLCertPublicKeyLength();

QString GetSSLCertSerialNumber();

QString GetSSLCertSignatureAlgorithm();

QByteArray GetSSLCertStore();
int SetSSLCertStore(QByteArray qbaSSLCertStore);

QString GetSSLCertStorePassword();
int SetSSLCertStorePassword(QString qsSSLCertStorePassword);

int GetSSLCertStoreType();
int SetSSLCertStoreType(int iSSLCertStoreType);

QString GetSSLCertSubject();
int SetSSLCertSubject(QString qsSSLCertSubject);

QString GetSSLCertSubjectAltNames();

QString GetSSLCertThumbprintMD5();

QString GetSSLCertThumbprintSHA1();

QString GetSSLCertThumbprintSHA256();

QString GetSSLCertUsage();

int GetSSLCertUsageFlags();

QString GetSSLCertVersion();

Remarks

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

Data Type

IPWorksDTLSCertificate

Config Method (DTLSServer Class)

This method sets or retrieves a configuration setting.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* Config(const char* lpszConfigurationString);

Unicode (Windows)
LPWSTR Config(LPCWSTR lpszConfigurationString);

char* ipworksdtls_dtlsserver_config(void* lpObj, const char* lpszConfigurationString);

QString Config(const QString& qsConfigurationString);

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, 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.

Error Handling (C++)

This method returns a String value; after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

Disconnect Method (DTLSServer Class)

This method disconnects the specified client.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Disconnect(int iConnectionId);

Unicode (Windows)
INT Disconnect(INT iConnectionId);

int ipworksdtls_dtlsserver_disconnect(void* lpObj, int iConnectionId);

int Disconnect(int iConnectionId);

Remarks

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

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

DoEvents Method (DTLSServer Class)

This method processes events from the internal message queue.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int DoEvents();

Unicode (Windows)
INT DoEvents();

int ipworksdtls_dtlsserver_doevents(void* lpObj);

int DoEvents();

Remarks

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

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

PauseData Method (DTLSServer Class)

This method pauses data reception.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int PauseData(int iConnectionId);

Unicode (Windows)
INT PauseData(INT iConnectionId);

int ipworksdtls_dtlsserver_pausedata(void* lpObj, int iConnectionId);

int PauseData(int iConnectionId);

Remarks

This method pauses data reception for the connection identified by ConnectionId when called. While data reception is paused, the DataIn event will not fire for the specified connection. Call ProcessData to reenable data reception.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

ProcessData Method (DTLSServer Class)

This method reenables data reception after a call to PauseData .

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int ProcessData(int iConnectionId);

Unicode (Windows)
INT ProcessData(INT iConnectionId);

int ipworksdtls_dtlsserver_processdata(void* lpObj, int iConnectionId);

int ProcessData(int iConnectionId);

Remarks

This method reenables data reception for the connection identified by ConnectionId after a previous call to PauseData. When PauseData is called, the DataIn event will not fire for the specified connection. 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.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Reset Method (DTLSServer Class)

This method will reset the class.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Reset();

Unicode (Windows)
INT Reset();

int ipworksdtls_dtlsserver_reset(void* lpObj);

int Reset();

Remarks

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

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

SendBytes Method (DTLSServer Class)

This method sends binary data to the specified client.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int SendBytes(int iConnectionId, const char* lpData, int lenData);

Unicode (Windows)
INT SendBytes(INT iConnectionId, LPCSTR lpData, INT lenData);

int ipworksdtls_dtlsserver_sendbytes(void* lpObj, int iConnectionId, const char* lpData, int lenData);

int SendBytes(int iConnectionId, QByteArray qbaData);

Remarks

This method sends binary data to the client identified by ConnectionId. For example:

byte[] dataToSend = new byte[] { 72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100, 33 }; foreach (DTLSConnection c in dtlsserver.Connections.Values) { dtlsserver.SendBytes(c.ConnectionId, dataToSend); }

To send text, use the SendText method instead.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

SendText Method (DTLSServer Class)

This method sends text to the specified client.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int SendText(int iConnectionId, const char* lpszText);

Unicode (Windows)
INT SendText(INT iConnectionId, LPCWSTR lpszText);

int ipworksdtls_dtlsserver_sendtext(void* lpObj, int iConnectionId, const char* lpszText);

int SendText(int iConnectionId, const QString& qsText);

Remarks

This method sends text to the client identified by ConnectionId. For example:

string dataToSend = "Hello world!"; foreach (DTLSConnection c in dtlsserver.Connections.Values) { dtlsserver.SendText(c.ConnectionId, dataToSend); }

To send binary data, use the SendBytes method instead.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Shutdown Method (DTLSServer Class)

This method shuts down the server.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Shutdown();

Unicode (Windows)
INT Shutdown();

int ipworksdtls_dtlsserver_shutdown(void* lpObj);

int Shutdown();

Remarks

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

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

StartListening Method (DTLSServer Class)

This method starts listening for incoming connections.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int StartListening();

Unicode (Windows)
INT StartListening();

int ipworksdtls_dtlsserver_startlistening(void* lpObj);

int StartListening();

Remarks

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

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

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

StopListening Method (DTLSServer Class)

This method stops listening for new connections.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int StopListening();

Unicode (Windows)
INT StopListening();

int ipworksdtls_dtlsserver_stoplistening(void* lpObj);

int StopListening();

Remarks

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

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

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Connected Event (DTLSServer Class)

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

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireConnected(DTLSServerConnectedEventParams *e);

typedef struct {
  int ConnectionId;
  const char *SourceAddr;
  int SourcePort;
  int StatusCode;
  const char *Description;
  int reserved;
} DTLSServerConnectedEventParams;


Unicode (Windows)
virtual INT FireConnected(DTLSServerConnectedEventParams *e);

typedef struct {
  INT ConnectionId;
  LPCWSTR SourceAddr;
  INT SourcePort;
  INT StatusCode;
  LPCWSTR Description;
  INT reserved;
} DTLSServerConnectedEventParams;

#define EID_DTLSSERVER_CONNECTED 1

virtual INT IPWORKSDTLS_CALL FireConnected(INT &iConnectionId, LPSTR &lpszSourceAddr, INT &iSourcePort, INT &iStatusCode, LPSTR &lpszDescription);

class DTLSServerConnectedEventParams {
public:
  int ConnectionId();

  const QString &SourceAddr();

  int SourcePort();

  int StatusCode();

  const QString &Description();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Connected(DTLSServerConnectedEventParams *e);

// Or, subclass DTLSServer and override this emitter function.
virtual int FireConnected(DTLSServerConnectedEventParams *e) {...}

Remarks

This event is fired immediately after a connection completes (or fails). The ConnectionId parameter indicates the unique ID assigned to this connection.

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

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

If the connection fails, StatusCode has the error code returned by the system. Description contains a description of this code. The value of StatusCode is equal to the value of the system error.

Please refer to the Error Codes section for more information.

ConnectionRequest Event (DTLSServer Class)

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

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireConnectionRequest(DTLSServerConnectionRequestEventParams *e);

typedef struct {
  const char *Address;
  int Port;
  int Accept;
  int reserved;
} DTLSServerConnectionRequestEventParams;


Unicode (Windows)
virtual INT FireConnectionRequest(DTLSServerConnectionRequestEventParams *e);

typedef struct {
  LPCWSTR Address;
  INT Port;
  BOOL Accept;
  INT reserved;
} DTLSServerConnectionRequestEventParams;

#define EID_DTLSSERVER_CONNECTIONREQUEST 2

virtual INT IPWORKSDTLS_CALL FireConnectionRequest(LPSTR &lpszAddress, INT &iPort, BOOL &bAccept);

class DTLSServerConnectionRequestEventParams {
public:
  const QString &Address();

  int Port();

  bool Accept();
  void SetAccept(bool bAccept);

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void ConnectionRequest(DTLSServerConnectionRequestEventParams *e);

// Or, subclass DTLSServer and override this emitter function.
virtual int FireConnectionRequest(DTLSServerConnectionRequestEventParams *e) {...}

Remarks

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

DataIn Event (DTLSServer Class)

This event is fired when data is received.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireDataIn(DTLSServerDataInEventParams *e);

typedef struct {
  int ConnectionId;
  const char *Datagram;
  int lenDatagram;
  int reserved;
} DTLSServerDataInEventParams;


Unicode (Windows)
virtual INT FireDataIn(DTLSServerDataInEventParams *e);

typedef struct {
  INT ConnectionId;
  LPCSTR Datagram;
  INT lenDatagram;
  INT reserved;
} DTLSServerDataInEventParams;

#define EID_DTLSSERVER_DATAIN 3

virtual INT IPWORKSDTLS_CALL FireDataIn(INT &iConnectionId, LPSTR &lpDatagram, INT &lenDatagram);

class DTLSServerDataInEventParams {
public:
  int ConnectionId();

  const QByteArray &Datagram();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void DataIn(DTLSServerDataInEventParams *e);

// Or, subclass DTLSServer and override this emitter function.
virtual int FireDataIn(DTLSServerDataInEventParams *e) {...}

Remarks

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

ConnectionId indicates the unique Id of the DTLSConnection from which the packet originated.

Datagram contains the packet as sent by the remote host.

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 (DTLSServer Class)

This event is fired when a connection is closed.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireDisconnected(DTLSServerDisconnectedEventParams *e);

typedef struct {
  int ConnectionId;
  int StatusCode;
  const char *Description;
  int reserved;
} DTLSServerDisconnectedEventParams;


Unicode (Windows)
virtual INT FireDisconnected(DTLSServerDisconnectedEventParams *e);

typedef struct {
  INT ConnectionId;
  INT StatusCode;
  LPCWSTR Description;
  INT reserved;
} DTLSServerDisconnectedEventParams;

#define EID_DTLSSERVER_DISCONNECTED 4

virtual INT IPWORKSDTLS_CALL FireDisconnected(INT &iConnectionId, INT &iStatusCode, LPSTR &lpszDescription);

class DTLSServerDisconnectedEventParams {
public:
  int ConnectionId();

  int StatusCode();

  const QString &Description();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Disconnected(DTLSServerDisconnectedEventParams *e);

// Or, subclass DTLSServer and override this emitter function.
virtual int FireDisconnected(DTLSServerDisconnectedEventParams *e) {...}

Remarks

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

If the connection is broken for any other reason, StatusCode has the error code returned by the system. Description contains a description of this code. The value of StatusCode is equal to the value of the system error.

Please refer to the Error Codes section for more information.

Error Event (DTLSServer Class)

This event fires information about errors during data delivery.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireError(DTLSServerErrorEventParams *e);

typedef struct {
  int ConnectionId;
  int ErrorCode;
  const char *Description;
  int reserved;
} DTLSServerErrorEventParams;


Unicode (Windows)
virtual INT FireError(DTLSServerErrorEventParams *e);

typedef struct {
  INT ConnectionId;
  INT ErrorCode;
  LPCWSTR Description;
  INT reserved;
} DTLSServerErrorEventParams;

#define EID_DTLSSERVER_ERROR 5

virtual INT IPWORKSDTLS_CALL FireError(INT &iConnectionId, INT &iErrorCode, LPSTR &lpszDescription);

class DTLSServerErrorEventParams {
public:
  int ConnectionId();

  int ErrorCode();

  const QString &Description();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Error(DTLSServerErrorEventParams *e);

// Or, subclass DTLSServer and override this emitter function.
virtual int FireError(DTLSServerErrorEventParams *e) {...}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally, the class fails with an error.

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.

ConnectionId indicates the connection for which the error is applicable.

Log Event (DTLSServer Class)

This event fires once for each log message.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireLog(DTLSServerLogEventParams *e);

typedef struct {
  int ConnectionId;
  int LogLevel;
  const char *Message;
  const char *LogType;
  int reserved;
} DTLSServerLogEventParams;


Unicode (Windows)
virtual INT FireLog(DTLSServerLogEventParams *e);

typedef struct {
  INT ConnectionId;
  INT LogLevel;
  LPCWSTR Message;
  LPCWSTR LogType;
  INT reserved;
} DTLSServerLogEventParams;

#define EID_DTLSSERVER_LOG 6

virtual INT IPWORKSDTLS_CALL FireLog(INT &iConnectionId, INT &iLogLevel, LPSTR &lpszMessage, LPSTR &lpszLogType);

class DTLSServerLogEventParams {
public:
  int ConnectionId();

  int LogLevel();

  const QString &Message();

  const QString &LogType();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Log(DTLSServerLogEventParams *e);

// Or, subclass DTLSServer and override this emitter function.
virtual int FireLog(DTLSServerLogEventParams *e) {...}

Remarks

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

LogLevel indicates the level of message. Possible values are as follows:

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"

SSLClientAuthentication Event (DTLSServer Class)

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

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireSSLClientAuthentication(DTLSServerSSLClientAuthenticationEventParams *e);

typedef struct {
  int ConnectionId;
  const char *CertEncoded;
  int lenCertEncoded;
  const char *CertSubject;
  const char *CertIssuer;
  const char *Status;
  int Accept;
  int reserved;
} DTLSServerSSLClientAuthenticationEventParams;


Unicode (Windows)
virtual INT FireSSLClientAuthentication(DTLSServerSSLClientAuthenticationEventParams *e);

typedef struct {
  INT ConnectionId;
  LPCSTR CertEncoded;
  INT lenCertEncoded;
  LPCWSTR CertSubject;
  LPCWSTR CertIssuer;
  LPCWSTR Status;
  BOOL Accept;
  INT reserved;
} DTLSServerSSLClientAuthenticationEventParams;

#define EID_DTLSSERVER_SSLCLIENTAUTHENTICATION 7

virtual INT IPWORKSDTLS_CALL FireSSLClientAuthentication(INT &iConnectionId, LPSTR &lpCertEncoded, INT &lenCertEncoded, LPSTR &lpszCertSubject, LPSTR &lpszCertIssuer, LPSTR &lpszStatus, BOOL &bAccept);

class DTLSServerSSLClientAuthenticationEventParams {
public:
  int ConnectionId();

  const QByteArray &CertEncoded();

  const QString &CertSubject();

  const QString &CertIssuer();

  const QString &Status();

  bool Accept();
  void SetAccept(bool bAccept);

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void SSLClientAuthentication(DTLSServerSSLClientAuthenticationEventParams *e);

// Or, subclass DTLSServer and override this emitter function.
virtual int FireSSLClientAuthentication(DTLSServerSSLClientAuthenticationEventParams *e) {...}

Remarks

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

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

SSLStatus Event (DTLSServer Class)

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

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireSSLStatus(DTLSServerSSLStatusEventParams *e);

typedef struct {
  int ConnectionId;
  const char *Message;
  int reserved;
} DTLSServerSSLStatusEventParams;


Unicode (Windows)
virtual INT FireSSLStatus(DTLSServerSSLStatusEventParams *e);

typedef struct {
  INT ConnectionId;
  LPCWSTR Message;
  INT reserved;
} DTLSServerSSLStatusEventParams;

#define EID_DTLSSERVER_SSLSTATUS 8

virtual INT IPWORKSDTLS_CALL FireSSLStatus(INT &iConnectionId, LPSTR &lpszMessage);

class DTLSServerSSLStatusEventParams {
public:
  int ConnectionId();

  const QString &Message();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void SSLStatus(DTLSServerSSLStatusEventParams *e);

// Or, subclass DTLSServer and override this emitter function.
virtual int FireSSLStatus(DTLSServerSSLStatusEventParams *e) {...}

Remarks

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

Certificate Type

This is the digital certificate being used.

Syntax

IPWorksDTLSCertificate (declared in ipworksdtls.h)

Remarks

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

Fields

Constructors

>

Certificate()

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

Certificate(const char* lpEncoded, int lenEncoded)

Parses CertificateData as an X509 public key.

Certificate(int iCertStoreType, const char* lpStoreBlob, int lenStoreBlob, const char* lpszStorePassword, const char* lpszSubject)

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).

DTLSConnection Type

This is a currently connected client.

Syntax

IPWorksDTLSDTLSConnection (declared in ipworksdtls.h)

Remarks

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

Fields

Constructors

DTLSConnection()

IPWorksDTLSList Type

Syntax

IPWorksDTLSList<T> (declared in ipworksdtls.h)

Remarks

IPWorksDTLSList is a generic class that is used to hold a collection of objects of type T, where T is one of the custom types supported by the DTLSServer class.

int GetCount() {}

int SetCount() {}

T* Get(int index) {}

T* Set(int index, T* value) {}

Config Settings (DTLSServer Class)

DTLSServer Config Settings

UDP Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (DTLSServer Class)

Error Handling (C++)

Call the GetLastErrorCode() method to obtain the last called method's result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. Known error codes are listed below. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

DTLSServer Errors