/// <summary> /// Connect to a VNC Host and determine which type of Authentication it uses. If the host uses Password Authentication, a call to Authenticate() will be required. /// </summary> /// <param name="host">The IP Address or Host Name of the VNC Host.</param> /// <param name="display">The Display number (used on Unix hosts).</param> /// <param name="port">The Port number used by the Host, usually 5900.</param> /// <param name="viewOnly">True if mouse/keyboard events are to be ignored.</param> /// <returns>Returns True if the VNC Host requires a Password to be sent after Connect() is called, otherwise False.</returns> public bool Connect(string host, int display, int port, bool viewOnly) { if (host == null) throw new ArgumentNullException("host"); // If a diplay number is specified (used to connect to Unix servers) // it must be 0 or greater. This gets added to the default port number // in order to determine where the server will be listening for connections. if (display < 0) throw new ArgumentOutOfRangeException("display", display, "Display number must be non-negative."); port += display; rfb = new RfbProtocol(); if (viewOnly) { inputPolicy = new VncViewInputPolicy(rfb); } else { inputPolicy = new VncDefaultInputPolicy(rfb); } // Connect and determine version of server, and set client protocol version to match try { rfb.Connect(host, port); rfb.ReadProtocolVersion(); rfb.WriteProtocolVersion(); // Figure out which type of authentication the server uses byte[] types = rfb.ReadSecurityTypes(); // Based on what the server sends back in the way of supported Security Types, one of // two things will need to be done: either the server will reject the connection (i.e., type = 0), // or a list of supported types will be sent, of which we need to choose and use one. if (types.Length > 0) { if (types[0] == 0) { // The server is not able (or willing) to accept the connection. // A message follows indicating why the connection was dropped. throw new VncProtocolException("Connection Failed. The server rejected the connection for the following reason: " + rfb.ReadSecurityFailureReason()); } else { securityType = GetSupportedSecurityType(types); Debug.Assert(securityType > 0, "Unknown Security Type(s)", "The server sent one or more unknown Security Types."); rfb.WriteSecurityType(securityType); // Protocol 3.8 states that a SecurityResult is still sent when using NONE (see 6.2.1) if (rfb.ServerVersion == 3.8f && securityType == 1) { if (rfb.ReadSecurityResult() > 0) { // For some reason, the server is not accepting the connection. Get the // reason and throw an exception throw new VncProtocolException("Unable to Connecto to the Server. The Server rejected the connection for the following reason: " + rfb.ReadSecurityFailureReason()); } } return (securityType > 1) ? true : false; } } else { // Something is wrong, since we should have gotten at least 1 Security Type throw new VncProtocolException("Protocol Error Connecting to Server. The Server didn't send any Security Types during the initial handshake."); } } catch (Exception e) { throw new VncProtocolException("Unable to connect to the server. Error was: " + e.Message, e); } }
/// <summary> /// Connect to a VNC Host and determine which type of Authentication it uses. If the host uses Password Authentication, /// a call to Authenticate() will be required. /// </summary> /// <param name="host">The IP Address or Host Name of the VNC Host.</param> /// <param name="display">The Display number (used on Unix hosts).</param> /// <param name="port">The Port number used by the Host, usually 5900.</param> /// <param name="viewOnly">True if mouse/keyboard events are to be ignored.</param> /// <returns>Returns True if the VNC Host requires a Password to be sent after Connect() is called, otherwise False.</returns> public bool Connect(string host, int display, int port, bool viewOnly) { if (host == null) { throw new ArgumentNullException(nameof(host)); } // If a diplay number is specified (used to connect to Unix servers) // it must be 0 or greater. This gets added to the default port number // in order to determine where the server will be listening for connections. if (display < 0) { throw new ArgumentOutOfRangeException(nameof(display), display, "Display number must be non-negative."); } port += display; rfb = new RfbProtocol(); viewOnlyMode = viewOnly; if (viewOnly) { inputPolicy = new VncViewInputPolicy(rfb); } else { inputPolicy = new VncDefaultInputPolicy(rfb); } // Connect and determine version of server, and set client protocol version to match try { rfb.Connect(host, port); rfb.ReadProtocolVersion(); // Handle possible repeater connection if (rfb.ServerVersion == 0.0) { rfb.WriteProxyAddress(); // Now we are connected to the real server; read the protocol version of the // server rfb.ReadProtocolVersion(); // Resume normal handshake and protocol } rfb.WriteProtocolVersion(); // Figure out which type of authentication the server uses var types = rfb.ReadSecurityTypes(); // Based on what the server sends back in the way of supported Security Types, one of // two things will need to be done: either the server will reject the connection (i.e., type = 0), // or a list of supported types will be sent, of which we need to choose and use one. if (types.Length <= 0) { // Something is wrong, since we should have gotten at least 1 Security Type throw new VncProtocolException( "Protocol Error Connecting to Server. The Server didn't send any Security Types during the initial handshake."); } if (types[0] == 0) { // The server is not able (or willing) to accept the connection. // A message follows indicating why the connection was dropped. throw new VncProtocolException( "Connection Failed. The server rejected the connection for the following reason: " + rfb.ReadSecurityFailureReason()); } securityType = GetSupportedSecurityType(types); Debug.Assert(securityType > 0, "Unknown Security Type(s)", "The server sent one or more unknown Security Types."); rfb.WriteSecurityType(securityType); // Protocol 3.8 states that a SecurityResult is still sent when using NONE (see 6.2.1) if (rfb.ServerVersion != 3.8f || securityType != 1) { return(securityType > 1); } if (rfb.ReadSecurityResult() > 0) { // For some reason, the server is not accepting the connection. Get the // reason and throw an exception throw new VncProtocolException( "Unable to Connecto to the Server. The Server rejected the connection for the following reason: " + rfb.ReadSecurityFailureReason()); } return(securityType > 1); } catch (Exception e) { throw new VncProtocolException("Unable to connect to the server. Error was: " + e.Message, e); } }