Address review comments.

src/IotHubMessaging.cs

@@ -34,6 +34,7 @@ namespace Opc.Ua.Publisher
         private ConcurrentQueue<string> _sendQueue;
         private int _currentSizeOfIotHubMessageBytes;
         private List<OpcUaMessage> _messageList;
+        private SemaphoreSlim _messageListSemaphore;
         private uint _maxSizeOfIoTHubMessageBytes;
         private int _defaultSendIntervalSeconds;
         private CancellationTokenSource _tokenSource;
@@ -47,6 +48,7 @@ namespace Opc.Ua.Publisher
             _sendQueue = new ConcurrentQueue<string>();
             _sendQueueEvent = new AutoResetEvent(false);
             _messageList = new List<OpcUaMessage>();
+            _messageListSemaphore = new SemaphoreSlim(1);
             _currentSizeOfIotHubMessageBytes = 0;
         }
 
@@ -141,7 +143,7 @@ namespace Opc.Ua.Publisher
             return true;
         }
 
-        public void UpdateConnectionString(string iotHubOwnerConnectionString)
+        public void ConnectionStringWrite(string iotHubOwnerConnectionString)
         {
             DeviceClient newClient = DeviceClient.CreateFromConnectionString(iotHubOwnerConnectionString, IotHubProtocol);
             newClient.RetryPolicy = RetryPolicyType.Exponential_Backoff_With_Jitter;
@@ -252,7 +254,9 @@ namespace Opc.Ua.Publisher
                             if (isDequeueSuccessful)
                             {
                                 OpcUaMessage msgPayload = JsonConvert.DeserializeObject<OpcUaMessage>(messageInJson);
+                                _messageListSemaphore.Wait();
                                 _messageList.Add(msgPayload);
+                                _messageListSemaphore.Release();
                                 _currentSizeOfIotHubMessageBytes = _currentSizeOfIotHubMessageBytes + nextMessageSizeBytes;
                                 Trace(Utils.TraceMasks.OperationDetail, $"Added new message with size {nextMessageSizeBytes} to IoTHub message (size is now {_currentSizeOfIotHubMessageBytes}). {_sendQueue.Count} message(s) in send queue.");
 
@@ -283,9 +287,13 @@ namespace Opc.Ua.Publisher
         {
             if (_messageList.Count > 0)
             {
+                // process all queued messages
+                _messageListSemaphore.Wait();
                 string msgListInJson = JsonConvert.SerializeObject(_messageList);
-
                 var encodedMessage = new Microsoft.Azure.Devices.Client.Message(Encoding.UTF8.GetBytes(msgListInJson));
+                _currentSizeOfIotHubMessageBytes = 0;
+                _messageList.Clear();
+                _messageListSemaphore.Release();
 
                 // publish
                 encodedMessage.Properties.Add("content-type", "application/opcua+uajson");
@@ -300,17 +308,13 @@ namespace Opc.Ua.Publisher
                     }
                     else
                     {
-                        Trace("No IoTHub client available ");
+                        Trace("No IoTHub client available. Dropping messages...");
                     }
                 }
                 catch (Exception e)
                 {
-                    Trace(e, "Exception while sending message to IoTHub. Dropping...");
+                    Trace(e, "Exception while sending message to IoTHub. Dropping messages...");
                 }
-
-                // reset IoTHub message size
-                _currentSizeOfIotHubMessageBytes = 0;
-                _messageList.Clear();
             }
 
             // Restart timer

src/ModuleConfiguration.cs

@@ -27,13 +27,11 @@ namespace Opc.Ua.Publisher
             Configuration.ClientConfiguration = new ClientConfiguration();
             Configuration.ServerConfiguration = new ServerConfiguration();
 
-            // enable logging and enforce information flag
+            // initialize stack tracing
-            Program.OpcStackTraceMask |= Utils.TraceMasks.Information;
             Configuration.TraceConfiguration = new TraceConfiguration()
             {
                 TraceMasks = Program.OpcStackTraceMask
             };
-            // StdOutAndFile is not working correct, due to a bug in the stack. Need to workaround with own Trace for now.
             Utils.SetTraceOutput(Utils.TraceOutput.FileOnly);
             if (string.IsNullOrEmpty(Program.LogFileName))
             {

src/OpcSession.cs

@@ -143,7 +143,7 @@ namespace Opc.Ua.Publisher
             _namespaceTable = new NamespaceTable();
         }
 
-        public async Task ConnectAndOrMonitor()
+        public async Task ConnectAndMonitor()
         {
             _opcSessionSemaphore.Wait();
             Trace($"Connect and monitor session and nodes on endpoint '{EndpointUri.AbsoluteUri}'.");

src/Program.cs

@@ -31,6 +31,7 @@ namespace Opc.Ua.Publisher
         public static string NodesToPublishAbsFilenameDefault = $"{System.IO.Directory.GetCurrentDirectory()}{Path.DirectorySeparatorChar}publishednodes.json";
         public static string NodesToPublishAbsFilename { get; set; }
         public static string ShopfloorDomain { get; set; }
+        public static bool VerboseConsole { get; set; }
 
         //
         // IoTHub related
@@ -58,8 +59,8 @@ namespace Opc.Ua.Publisher
         public static int OpcOperationTimeout = 120000;
         public static bool TrustMyself = true;
         // Enable Utils.TraceMasks.OperationDetail to get output for IoTHub telemetry operations. Current: 0x287 (647), with OperationDetail: 0x2C7 (711)
-        public static int OpcStackTraceMask = Utils.TraceMasks.Error | Utils.TraceMasks.Security | Utils.TraceMasks.StackTrace | Utils.TraceMasks.StartStop | Utils.TraceMasks.Information;
+        public static int OpcStackTraceMask = Utils.TraceMasks.Error | Utils.TraceMasks.Security | Utils.TraceMasks.StackTrace | Utils.TraceMasks.StartStop;
-        public static bool OpcPublisherAutoAccept = false;
+        public static bool OpcPublisherAutoTrustServerCerts = false;
         public static uint OpcSessionCreationTimeout = 10;
         public static uint OpcSessionCreationBackoffMax = 5;
         public static uint OpcKeepAliveDisconnectThreshold = 10;
@@ -132,12 +133,12 @@ namespace Opc.Ua.Publisher
             {
                 var shouldShowHelp = false;
 
-                // these are the available options, not that they set the variables
+                // command line options configuration
                 Mono.Options.OptionSet options = new Mono.Options.OptionSet {
                     // Publishing configuration options
                     { "pf|publishfile=", $"the filename to configure the nodes to publish.\nDefault: '{NodesToPublishAbsFilenameDefault}'", (string p) => NodesToPublishAbsFilename = p },
                     { "sd|shopfloordomain=", $"the domain of the shopfloor. if specified this domain is appended (delimited by a ':' to the 'ApplicationURI' property when telemetry is ingested to IoTHub.\n" +
-                            "The value must follw the syntactical rules of a DNS hostname.\nDefault: not set", (string s) => {
+                            "The value must follow the syntactical rules of a DNS hostname.\nDefault: not set", (string s) => {
                             Regex domainNameRegex = new Regex("^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\\-]*[a-zA-Z0-9])\\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\\-]*[A-Za-z0-9])$");
                             if (domainNameRegex.IsMatch(s))
                             {
@@ -149,7 +150,7 @@ namespace Opc.Ua.Publisher
                             }
                         }
                      },
-                    { "sw|sessionconnectwait=", $"specify the wait time in seconds publisher is trying to connect to disconnected endpoints\nMin: 10\nDefault: {PublisherSessionConnectWaitSec}", (int i) => {
+                    { "sw|sessionconnectwait=", $"specify the wait time in seconds publisher is trying to connect to disconnected endpoints and starts monitoring unmonitored items\nMin: 10\nDefault: {PublisherSessionConnectWaitSec}", (int i) => {
                             if (i > 10)
                             {
                                 PublisherSessionConnectWaitSec = i;
@@ -160,6 +161,7 @@ namespace Opc.Ua.Publisher
                             }
                         }
                     },
+                    { "vc|verboseconsole=", $"the output of publisher is shown on the console.\nDefault: {VerboseConsole}", (bool b) => VerboseConsole = b },
 
                     // IoTHub specific options
                     { "ih|iothubprotocol=", $"the protocol to use for communication with Azure IoTHub (allowed values: {string.Join(", ", Enum.GetNames(IotHubProtocol.GetType()))}).\nDefault: {Enum.GetName(IotHubProtocol.GetType(), IotHubProtocol)}",
@@ -214,7 +216,8 @@ namespace Opc.Ua.Publisher
                             }
                         }
                     },
-                    { "ds|defaultsamplingrate=", $"the sampling rate in millisecond for which monitored nodes should be queried.\nMin: 100\nDefault: {OpcSamplingRateMillisec}", (int i) => {
+                    { "ds|defaultsamplingrate=", $"the sampling interval in milliseconds, the OPC UA servers should use to sample the values of the nodes to publish.\n" +
+                        $"Please check the OPC UA spec for more details.\nMin: 100\nDefault: {OpcSamplingRateMillisec}", (int i) => {
                             if (i >= 100)
                             {
                                 OpcSamplingRateMillisec = i;
@@ -258,7 +261,7 @@ namespace Opc.Ua.Publisher
                             }
                         }
                     },
-                    { "st|opcstacktracemask=", $"the trace mask for the OPC stack. See github OPC .NET stack for definitions.\nTo enable IoTHub telemetry tracing set it to 711. Information mask 0x2 is enforced.\nDefault: {OpcStackTraceMask:X}  ({Program.OpcStackTraceMask})", (int i) => {
+                    { "st|opcstacktracemask=", $"the trace mask for the OPC stack. See github OPC .NET stack for definitions.\nTo enable IoTHub telemetry tracing set it to 711.\nDefault: {OpcStackTraceMask:X}  ({Program.OpcStackTraceMask})", (int i) => {
                             if (i >= 0)
                             {
                                 OpcStackTraceMask = i;
@@ -269,7 +272,7 @@ namespace Opc.Ua.Publisher
                             }
                         }
                     },
-                    { "aa|autoaccept=", $"the publisher accept all servers it is connecting to.\nDefault: {OpcPublisherAutoAccept}", (bool b) => OpcPublisherAutoAccept = b },
+                    { "as|autotrustservercerts=", $"the publisher trusts all servers it is establishing a connection to.\nDefault: {OpcPublisherAutoTrustServerCerts}", (bool b) => OpcPublisherAutoTrustServerCerts = b },
 
                     // trust own public cert option
                     { "tm|trustmyself=", $"the publisher certificate is put into the trusted certificate store automatically.\nDefault: {TrustMyself}", (bool b) => TrustMyself = b },
@@ -418,14 +421,14 @@ namespace Opc.Ua.Publisher
                 }
 
                 // Set certificate validator.
-                if (OpcPublisherAutoAccept)
+                if (OpcPublisherAutoTrustServerCerts)
                 {
-                    Trace("Publisher configured to auto trust server certificates.");
+                    Trace("Publisher configured to auto trust server certificates of the servers it is connecting to.");
-                    OpcConfiguration.CertificateValidator.CertificateValidation += new CertificateValidationEventHandler(CertificateValidator_AutoAccept);
+                    OpcConfiguration.CertificateValidator.CertificateValidation += new CertificateValidationEventHandler(CertificateValidator_AutoTrustServerCerts);
                 }
                 else
                 {
-                    Trace("Publisher configured to not auto trust server certificates, but use certificate stores.");
+                    Trace("Publisher configured to not auto trust server certificates. When connecting to servers, you need to manually copy the rejected server certs to the trusted store to trust them.");
                     OpcConfiguration.CertificateValidator.CertificateValidation += new CertificateValidationEventHandler(CertificateValidator_Default);
                 }
 
@@ -542,11 +545,11 @@ namespace Opc.Ua.Publisher
                 Task.Run( async () => await SessionConnector(cts.Token));
 
                 // stop on user request
-                Trace("");
+                WriteLine("");
-                Trace("");
+                WriteLine("");
-                Trace("Publisher is running. Press ENTER to quit.");
+                WriteLine("Publisher is running. Press ENTER to quit.");
-                Trace("");
+                WriteLine("");
-                Trace("");
+                WriteLine("");
                 ReadLine();
                 cts.Cancel();
 
@@ -595,7 +598,7 @@ namespace Opc.Ua.Publisher
                 try
                 {
                     // get tasks for all disconnected sessions and start them
-                    var singleSessionHandlerTaskList = OpcSessions.Where(p => p.State == OpcSession.SessionState.Disconnected).Select(s => s.ConnectAndOrMonitor());
+                    var singleSessionHandlerTaskList = OpcSessions.Where(p => p.State == OpcSession.SessionState.Disconnected).Select(s => s.ConnectAndMonitor());
                     await Task.WhenAll(singleSessionHandlerTaskList);
                 }
                 catch (Exception e)
@@ -643,13 +646,13 @@ namespace Opc.Ua.Publisher
         }
 
         /// <summary>
-        /// Default certificate validation callback
+        /// Auto trust server certificate validation callback
         /// </summary>
-        private static void CertificateValidator_AutoAccept(CertificateValidator validator, CertificateValidationEventArgs e)
+        private static void CertificateValidator_AutoTrustServerCerts(CertificateValidator validator, CertificateValidationEventArgs e)
         {
             if (e.Error.StatusCode == StatusCodes.BadCertificateUntrusted)
             {
-                Trace($"Certificate '{e.Certificate.Subject}' will be auto accepted.");
+                Trace($"Certificate '{e.Certificate.Subject}' will be trusted, since the autotrustservercerts options was specified.");
                 e.Accept = true;
                 return;
             }

src/PublisherState.cs

@@ -83,8 +83,8 @@ namespace Publisher
                 opcSession.AddNodeForMonitoring(nodeToPublish.NodeId);
                 Trace("DoPublish: Requested to monitor item.");
 
-                // do whatever is needed.
+                // start monitoring the node
-                Task monitorTask = Task.Run(async () => await opcSession.ConnectAndOrMonitor());
+                Task monitorTask = Task.Run(async () => await opcSession.ConnectAndMonitor());
                 monitorTask.Wait();
                 Trace("DoPublish: Session processing completed.");
 
@@ -134,7 +134,7 @@ namespace Publisher
                 return ServiceResult.Create(StatusCodes.BadArgumentsMissing, "Please provide a valid OPC UA endpoint URL as second argument!");
             }
 
-            // Find the session and stop monitoring the item.
+            // Find the session and stop monitoring the node.
             try
             {
                 // find the session we need to monitor the node
@@ -154,8 +154,8 @@ namespace Publisher
                 opcSession.TagNodeForMonitoringStop(nodeToUnpublish.NodeId);
                 Trace("UnPublishNodeMethod: Requested to stop monitoring of node.");
 
-                // do whatever is needed.
+                // stop monitoring the node
-                Task monitorTask = Task.Run(async () => await opcSession.ConnectAndOrMonitor());
+                Task monitorTask = Task.Run(async () => await opcSession.ConnectAndMonitor());
                 monitorTask.Wait();
                 Trace("UnPublishNodeMethod: Session processing completed.");
 
@@ -213,7 +213,7 @@ namespace Publisher
             // configure publisher and write connection string
             try
             {
-                IotHubMessaging.UpdateConnectionString(connectionString);
+                IotHubMessaging.ConnectionStringWrite(connectionString);
             }
             catch (Exception e)
             {

src/SecureIoTHubToken.cs

@@ -21,14 +21,42 @@ namespace IoTHubCredentialTools
 {
     public class SecureIoTHubToken
     {
+        private static string CheckForToken(X509Certificate2 cert, string name)
+        {
+            if ((cert.SubjectName.Decode(X500DistinguishedNameFlags.None | X500DistinguishedNameFlags.DoNotUseQuotes).Equals("CN=" + name, StringComparison.OrdinalIgnoreCase)) &&
+                (DateTime.Now < cert.NotAfter))
+            {
+                using (RSA rsa = cert.GetRSAPrivateKey())
+                {
+                    if (rsa != null)
+                    {
+                        foreach (System.Security.Cryptography.X509Certificates.X509Extension extension in cert.Extensions)
+                        {
+                            // check for instruction code extension
+                            if ((extension.Oid.Value == "2.5.29.23") && (extension.RawData.Length >= 4))
+                            {
+                                byte[] bytes = new byte[extension.RawData.Length - 4];
+                                Array.Copy(extension.RawData, 4, bytes, 0, bytes.Length);
+                                byte[] token = rsa.Decrypt(bytes, RSAEncryptionPadding.OaepSHA1);
+                                return Encoding.ASCII.GetString(token);
+                            }
+                        }
+                    }
+                }
+            }
+            return null;
+        }
+
         public static string Read(string name, string storeType, string storePath)
         {
+            string token = null;
+
             // handle each store type differently
             switch (storeType)
             {
                 case CertificateStoreType.Directory:
                     {
-                        // load an existing key from a no-expired cert with the subject name passed in from the OS-provided X509Store
+                        // search a non expired cert with the given subject in the directory cert store and return the token
                         using (DirectoryCertificateStore store = new DirectoryCertificateStore())
                         {
                             store.Open(storePath);
@@ -36,64 +64,32 @@ namespace IoTHubCredentialTools
 
                             foreach (X509Certificate2 cert in certificates)
                             {
-                                if ((cert.SubjectName.Decode(X500DistinguishedNameFlags.None | X500DistinguishedNameFlags.DoNotUseQuotes).Equals("CN=" + name, StringComparison.OrdinalIgnoreCase)) &&
+                                if ((token = CheckForToken(cert, name)) != null)
-                                    (DateTime.Now < cert.NotAfter))
                                 {
-                                    using (RSA rsa = cert.GetRSAPrivateKey())
+                                    return token;
-                                    {
-                                        if (rsa != null)
-                                        {
-                                            foreach (System.Security.Cryptography.X509Certificates.X509Extension extension in cert.Extensions)
-                                            {
-                                                // check for instruction code extension
-                                                if ((extension.Oid.Value == "2.5.29.23") && (extension.RawData.Length >= 4))
-                                                {
-                                                    byte[] bytes = new byte[extension.RawData.Length - 4];
-                                                    Array.Copy(extension.RawData, 4, bytes, 0, bytes.Length);
-                                                    byte[] token = rsa.Decrypt(bytes, RSAEncryptionPadding.OaepSHA1);
-                                                    return Encoding.ASCII.GetString(token);
-                                                }
-                                            }
-                                        }
-                                    }
                                 }
                             }
                         }
                         break;
                     }
+
                 case CertificateStoreType.X509Store:
                     {
-                        // load an existing key from a no-expired cert with the subject name passed in from the OS-provided X509Store
+                        // search a non expired cert with the given subject in the X509 cert store and return the token
                         using (X509Store store = new X509Store(storePath, StoreLocation.CurrentUser))
                         {
                             store.Open(OpenFlags.ReadOnly);
                             foreach (X509Certificate2 cert in store.Certificates)
                             {
-                                if ((cert.SubjectName.Decode(X500DistinguishedNameFlags.None | X500DistinguishedNameFlags.DoNotUseQuotes).Equals("CN=" + name, StringComparison.OrdinalIgnoreCase)) &&
+                                if ((token = CheckForToken(cert, name)) != null)
-                                    (DateTime.Now < cert.NotAfter))
                                 {
-                                    using (RSA rsa = cert.GetRSAPrivateKey())
+                                    return token;
-                                    {
-                                        if (rsa != null)
-                                        {
-                                            foreach (System.Security.Cryptography.X509Certificates.X509Extension extension in cert.Extensions)
-                                            {
-                                                // check for instruction code extension
-                                                if ((extension.Oid.Value == "2.5.29.23") && (extension.RawData.Length >= 4))
-                                                {
-                                                    byte[] bytes = new byte[extension.RawData.Length - 4];
-                                                    Array.Copy(extension.RawData, 4, bytes, 0, bytes.Length);
-                                                    byte[] token = rsa.Decrypt(bytes, RSAEncryptionPadding.OaepSHA1);
-                                                    return Encoding.ASCII.GetString(token);
-                                                }
-                                            }
-                                        }
-                                    }
                                 }
                             }
                         }
                         break;
                     }
+
                 default:
                     {
                         throw new Exception($"The requested store type '{storeType}' is not supported. Please change.");

src/TraceWorkaround.cs

@@ -13,14 +13,17 @@ namespace Opc.Ua.Workarounds
         /// </summary>
         public static void Trace(string message, params object[] args)
         {
-            Utils.Trace(Utils.TraceMasks.Information, message, args);
+            Utils.Trace(Utils.TraceMasks.Error, message, args);
-            WriteLine(DateTime.Now.ToString() + ": " + message, args);
+            if (VerboseConsole)
+            {
+                WriteLine(DateTime.Now.ToString() + ": " + message, args);
+            }
         }
 
         public static void Trace(int traceMask, string format, params object[] args)
         {
             Utils.Trace(traceMask, format, args);
-            if ((OpcStackTraceMask & traceMask) != 0)
+            if (VerboseConsole && (OpcStackTraceMask & traceMask) != 0)
             {
                 WriteLine(DateTime.Now.ToString() + ": " + format, args);
             }