Class DtlsSrtpTransport

Class for managing the transport logic for a DTLS SRTP client or a server.

Inheritance

object

DtlsSrtpTransport

Implements

DatagramTransport

TlsCloseable

IDisposable

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: SipLib.Dtls

Assembly: SipLib.dll

Syntax

public class DtlsSrtpTransport : DatagramTransport, TlsCloseable, IDisposable

Constructors

DtlsSrtpTransport(IDtlsSrtpPeer, int)

Constructor

Declaration

public DtlsSrtpTransport(IDtlsSrtpPeer connection, int mtu = 1500)

Parameters

Type	Name	Description
IDtlsSrtpPeer	connection	A DtlsSrtpClient object or a DtlsSrtpServer object that this transport object will manage
int	mtu	Maximum transfer unit for the network. Defaults to 1500.

Fields

OnDataReady

Event that is fired when there is data that needs to be sent via UDP

Declaration

public Action<byte[]>? OnDataReady

Field Value

Type	Description
Action<byte[]>

RetransmissionMilliseconds

Sets the period in milliseconds that receive will wait before try retransmission

Declaration

public int RetransmissionMilliseconds

Field Value

Type	Description
int

TimeoutMilliseconds

Sets the period in milliseconds that the handshake attempt will timeout after.

Declaration

public int TimeoutMilliseconds

Field Value

Type	Description
int

Properties

IsClient

Returns true if this transport object is for a DTLS client or false if its for a DTLS server.

Declaration

public bool IsClient { get; }

Property Value

Type	Description
bool

SrtcpDecoder

Gets the SRTCP decoder

Declaration

public IPacketTransformer SrtcpDecoder { get; }

Property Value

Type	Description
IPacketTransformer

SrtcpEncoder

Gets the SRTCP decoder

Declaration

public IPacketTransformer SrtcpEncoder { get; }

Property Value

Type	Description
IPacketTransformer

SrtpDecoder

Gets the SRTP decoder

Declaration

public IPacketTransformer SrtpDecoder { get; }

Property Value

Type	Description
IPacketTransformer

SrtpEncoder

Gets the SRTP encoder

Declaration

public IPacketTransformer SrtpEncoder { get; }

Property Value

Type	Description
IPacketTransformer

Transport

Gets or sets the DTLS transport object

Declaration

public DtlsTransport? Transport { get; }

Property Value

Type	Description
DtlsTransport

Methods

BackOff(int)

Handle retransmission time based in DTLS 1.3

Declaration

protected virtual int BackOff(int currentWaitMillis)

Parameters

Type	Name	Description
int	currentWaitMillis

Returns

Type	Description
int

Close()

Closes this transport object.

Declaration

public virtual void Close()

Dispose()

Close the transport if the instance is out of scope.

Declaration

public void Dispose()

Dispose(bool)

Close the transport if the instance is out of scope.

Declaration

protected void Dispose(bool disposing)

Parameters

Type	Name	Description
bool	disposing

DoHandshake(out string?)

Starts the DTLS handshake as a client or as a server. This method blocks until the handshake is complete.

Declaration

public bool DoHandshake(out string? handshakeError)

Parameters

Type	Name	Description
string	handshakeError	Set to a string that describes the handshake error. Set to null if no errors occurred. Will be non-null if this method returns false.

Returns

Type	Description
bool	Returns true if successful or false if a handshake error occurred.

GenerateRtcpDecoder()

Generates an IPacketTransformer interface to use to decode RTCP packets

Declaration

protected IPacketTransformer GenerateRtcpDecoder()

Returns

Type	Description
IPacketTransformer

GenerateRtcpEncoder()

Generates an IPacketTransformer interface to use to encode RTCP packets

Declaration

protected IPacketTransformer GenerateRtcpEncoder()

Returns

Type	Description
IPacketTransformer

GenerateRtpDecoder()

Generates an IPacketTransformer interface to use to decode RTP packets

Declaration

protected IPacketTransformer GenerateRtpDecoder()

Returns

Type	Description
IPacketTransformer

GenerateRtpEncoder()

Generates an IPacketTransformer interface to use to encode RTP packets

Declaration

protected IPacketTransformer GenerateRtpEncoder()

Returns

Type	Description
IPacketTransformer

GenerateTransformer(bool, bool)

Generates an IPacketTransformer for a DTLS client or server for RTP or RTCP packets

Declaration

protected IPacketTransformer GenerateTransformer(bool isClient, bool isRtp)

Parameters

Type	Name	Description
bool	isClient	Set to true to generate the transformer for the client or false to generate the transformer for the server.
bool	isRtp	Set to true to generate the transformer for RTP packets or to false to generate the transformer for RTCP packets

Returns

Type	Description
IPacketTransformer

GetMasterClientKey()

Gets the client's master key

Declaration

protected byte[] GetMasterClientKey()

Returns

Type	Description
byte[]

GetMasterClientSalt()

Gets the client's master salt

Declaration

protected byte[] GetMasterClientSalt()

Returns

Type	Description
byte[]

GetMasterServerKey()

Gets the server's master key

Declaration

protected byte[] GetMasterServerKey()

Returns

Type	Description
byte[]

GetMasterServerSalt()

Gets the server's master salt

Declaration

protected byte[] GetMasterServerSalt()

Returns

Type	Description
byte[]

GetReceiveLimit()

Returns the maximum number of bytes that can be received

Declaration

public int GetReceiveLimit()

Returns

Type	Description
int

GetRemoteCertificate()

Gets the X.509 certificate of the remote peer

Declaration

public Certificate GetRemoteCertificate()

Returns

Type	Description
Certificate

GetSendLimit()

Returns the maximum number of bytes that can be sent

Declaration

public int GetSendLimit()

Returns

Type	Description
int

GetSrtcpPolicy()

Gets the SRTCP encryption and authenticaion policy information for the DTLS-SRTP session

Declaration

protected SrtpPolicy GetSrtcpPolicy()

Returns

Type	Description
SrtpPolicy

GetSrtpPolicy()

Gets the SRTCP encryption and authenticaion policy information for the DTLS-SRTP session

Declaration

protected SrtpPolicy GetSrtpPolicy()

Returns

Type	Description
SrtpPolicy

IsHandshakeComplete()

Returns true if the DTLS handshake is complete or false if it is not

Declaration

public bool IsHandshakeComplete()

Returns

Type	Description
bool

IsHandshakeFailed()

Returns true if the DTLS hanshake failed or false if it did not

Declaration

public bool IsHandshakeFailed()

Returns

Type	Description
bool

IsHandshaking()

Returns true if the DTLS handshake is in progress

Declaration

public bool IsHandshaking()

Returns

Type	Description
bool

ProtectRTCP(byte[], int, int)

Protects (encrypts) a compete RTCP packet

Declaration

public byte[] ProtectRTCP(byte[] packet, int offset, int length)

Parameters

Type	Name	Description
byte[]	packet	The complete RTCP packet to protect
int	offset	Offset to the RTCP packet
int	length	Number of bytes in the RTCP packet

Returns

Type	Description
byte[]	Returns the encrypted RTCP packet

ProtectRTP(byte[], int, int)

Protects (encrypts) a complete RTP packet.

Declaration

public byte[] ProtectRTP(byte[] packet, int offset, int length)

Parameters

Type	Name	Description
byte[]	packet	Complete RTP packet to encrypt
int	offset	Offset to the RTP packet
int	length	Number of bytes in the RTP packet

Returns

Type	Description
byte[]	Returns the encrypted RTP packet

Receive(byte[], int, int, int)

Implementation of the ReciveMethod of the BouncyCastle DatagramTransport interface. Users of the DtlsSrtpTransport class must not call this method.

Declaration

public int Receive(byte[] buf, int off, int len, int waitMillis)

Parameters

Type	Name	Description
byte[]	buf
int	off
int	len
int	waitMillis

Returns

Type	Description
int

Send(byte[], int, int)

Implementation of the Send() method of the BouncyCastle DatagramTransport interface. Users of the DtlsSrtpTransport class must not call this method.

Declaration

public void Send(byte[] buf, int off, int len)

Parameters

Type	Name	Description
byte[]	buf
int	off
int	len

UnprotectRTCP(byte[], int, int)

Unprotects (decrypts) a complete RTCP packet

Declaration

public byte[] UnprotectRTCP(byte[] packet, int offset, int length)

Parameters

Type	Name	Description
byte[]	packet	Complete RTCP packet to decrypt
int	offset	Offset to the RTCP packet
int	length	Number of bytes in the RTCP packet

Returns

Type	Description
byte[]	Returns the decrypted RTCP packet

UnprotectRTP(byte[], int, int)

Unprotects (decrypts) an RTP packet received from the remote endpoint. Only call this method if IsHandshake() complete returns true and IsHandshakeFailed() returns false

Declaration

public byte[] UnprotectRTP(byte[] packet, int offset, int length)

Parameters

Type	Name	Description
byte[]	packet	Complete RTP packet that was receivedincluding the RTP header
int	offset	Offset into the input of the RTP packet
int	length	Number of bytes in the RTP packet

Returns

Type	Description
byte[]

WriteToRecvStream(byte[])

Call this method to send a UDP packet that has been received from the network to the receive stream of the DTLS handshake logic. Only call this method if the DTLS handshake has not been completed.

Declaration

public void WriteToRecvStream(byte[] buf)

Parameters

Type	Name	Description
byte[]	buf	The UDP packet that was received from the network.

Events

OnAlert

Event that is fired if a DTlS protocol Alert occurs

Declaration

public event Action<AlertLevelsEnum, AlertTypesEnum, string>? OnAlert

Event Type

Type	Description
Action<AlertLevelsEnum, AlertTypesEnum, string>

Implements

Org.BouncyCastle.Crypto.Tls.DatagramTransport

Org.BouncyCastle.Crypto.Tls.TlsCloseable

IDisposable