SNMPv3 over DTLS

SharpSnmpLib/Header.cs

@@ -76,14 +76,27 @@ public Header(ISnmpData data)
         /// <param name="messageId">The message id.</param>
         /// <param name="maxMessageSize">Size of the max message.</param>
         /// <param name="securityLevel">The security level.</param>
+        /// <param name="securityModel">The security model.</param>
         /// <remarks>If you want an empty header, please use <see cref="Empty"/>.</remarks>
-        public Header(Integer32? messageId, Integer32 maxMessageSize, Levels securityLevel)
+        public Header(Integer32? messageId, Integer32 maxMessageSize, Levels securityLevel, Integer32 securityModel)
         {
-            _messageId = messageId;
+            _messageId = messageId; 
             _maxSize = maxMessageSize ?? throw new ArgumentNullException(nameof(maxMessageSize));
             SecurityLevel = securityLevel;
             _flags = new OctetString(SecurityLevel);
-            _securityModel = DefaultSecurityModel;
+            _securityModel = securityModel;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Header"/> class.
+        /// </summary>
+        /// <param name="messageId">The message id.</param>
+        /// <param name="maxMessageSize">Size of the max message.</param>
+        /// <param name="securityLevel">The security level.</param>
+        /// <remarks>If you want an empty header, please use <see cref="Empty"/>.</remarks>
+        public Header(Integer32? messageId, Integer32 maxMessageSize, Levels securityLevel) 
+            : this(messageId, maxMessageSize, securityLevel, DefaultSecurityModel)
+        {
         }
 
         /// <summary>
@@ -102,6 +115,15 @@ public Header(Integer32? messageId, Integer32 maxMessageSize, Levels securityLev
         /// <value>The message ID.</value>
         public int MessageId => _messageId == null ? throw new InvalidOperationException() : _messageId.ToInt32();
 
+        /// <summary>
+        /// Gets the security model.
+        /// </summary>
+        /// <value>The security model.</value>
+        public SecurityModel SecurityModel
+        {
+            get { return (SecurityModel)_securityModel.ToInt32(); }
+        }
+
         #region ISegment Members
 
         /// <summary>

SharpSnmpLib/Messaging/Discoverer.cs

@@ -317,7 +317,7 @@ public async Task DiscoverAsync(VersionCode version, IPEndPoint broadcastAddress
             using var udp = new Socket(addressFamily, SocketType.Dgram, ProtocolType.Udp);
             udp.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, true);
             var buffer = new ArraySegment<byte>(bytes);
-            await udp.SendToAsync(buffer, SocketFlags.None, broadcastAddress);
+            await udp.SendToAsync(buffer, SocketFlags.None, broadcastAddress).ConfigureAwait(false);
 
             var activeBefore = Interlocked.CompareExchange(ref _active, Active, Inactive);
             if (activeBefore == Active)
@@ -341,7 +341,8 @@ public async Task DiscoverAsync(VersionCode version, IPEndPoint broadcastAddress
 #else
             await Task.WhenAny(
                 ReceiveAsync(udp),
-                Task.Delay(interval));
+                Task.Delay(interval))
+                .ConfigureAwait(false);
 #endif
             Interlocked.CompareExchange(ref _active, Inactive, Active);
             try
@@ -370,7 +371,7 @@ private async Task ReceiveAsync(Socket socket)
                     EndPoint remote = new IPEndPoint(IPAddress.Any, 0);
 
                     var buffer = new byte[_bufferSize];
-                    var result = await socket.ReceiveMessageFromAsync(new ArraySegment<byte>(buffer), SocketFlags.None, remote);
+                    var result = await socket.ReceiveMessageFromAsync(new ArraySegment<byte>(buffer), SocketFlags.None, remote).ConfigureAwait(false);
                     await Task.Factory.StartNew(() => HandleMessage(buffer, result.ReceivedBytes, (IPEndPoint) result.RemoteEndPoint))
                         .ConfigureAwait(false);
                 }

SharpSnmpLib/Messaging/GetBulkRequestMessage.cs

@@ -107,6 +107,69 @@ public GetBulkRequestMessage(VersionCode version, int messageId, int requestId,
         {
         }
 
+        /// <summary>
+        /// Creates a <see cref="GetBulkRequestMessage"/> with a specific <see cref="Sequence"/>.
+        /// </summary>
+        /// <param name="version">The version.</param>
+        /// <param name="messageId">The message id.</param>
+        /// <param name="requestId">The request id.</param>
+        /// <param name="contextName">Context name.</param>
+        /// <param name="nonRepeaters">The non repeaters.</param>
+        /// <param name="maxRepetitions">The max repetitions.</param>
+        /// <param name="variables">The variables.</param>
+        /// <param name="privacy">The privacy provider.</param>
+        /// <param name="maxMessageSize">Size of the max message.</param>
+        public GetBulkRequestMessage(VersionCode version, int messageId, int requestId, OctetString contextName, int nonRepeaters, int maxRepetitions, IList<Variable> variables, IPrivacyProvider privacy, int maxMessageSize)
+        {
+            if (variables == null)
+            {
+                throw new ArgumentNullException(nameof(variables));
+            }
+
+            if (contextName == null)
+            {
+                throw new ArgumentNullException(nameof(contextName));
+            }
+
+            if (version != VersionCode.V3)
+            {
+                throw new ArgumentException("Only v3 is supported.", nameof(version));
+            }
+
+            if (privacy == null)
+            {
+                throw new ArgumentNullException(nameof(privacy));
+            }
+
+            if (nonRepeaters > variables.Count)
+            {
+                throw new ArgumentException("nonRepeaters should not be greater than variable count.", nameof(nonRepeaters));
+            }
+
+            if (maxRepetitions < 1)
+            {
+                throw new ArgumentException("maxRepetitions should be greater than 0.", nameof(maxRepetitions));
+            }
+
+            Version = version;
+            Privacy = privacy;
+
+            // TODO: define more constants.
+            Header = new Header(new Integer32(messageId), new Integer32(maxMessageSize), privacy.ToSecurityLevel() | Levels.Reportable, new Integer32((int)SecurityModel.Tsm));
+            Parameters = SecurityParameters.Empty;
+
+            var pdu = new GetBulkRequestPdu(
+                requestId,
+                nonRepeaters,
+                maxRepetitions,
+                variables);
+            var contextEngineId = OctetString.Empty;
+            Scope = new Scope(contextEngineId, contextName, pdu);
+
+            Privacy.ComputeHash(Version, Header, Parameters, Scope);
+            _bytes = this.PackMessage(null).ToBytes();
+        }
+
         /// <summary>
         /// Creates a <see cref="GetBulkRequestMessage"/> with a specific <see cref="Sequence"/>.
         /// </summary>
@@ -121,7 +184,8 @@ public GetBulkRequestMessage(VersionCode version, int messageId, int requestId,
         /// <param name="privacy">The privacy provider.</param>
         /// <param name="maxMessageSize">Size of the max message.</param>
         /// <param name="report">The report.</param>
-        public GetBulkRequestMessage(VersionCode version, int messageId, int requestId, OctetString userName, OctetString contextName, int nonRepeaters, int maxRepetitions, IList<Variable> variables, IPrivacyProvider privacy, int maxMessageSize, ISnmpMessage report)
+        /// <param name="securityModel">The security model.</param>
+        public GetBulkRequestMessage(VersionCode version, int messageId, int requestId, OctetString userName, OctetString contextName, int nonRepeaters, int maxRepetitions, IList<Variable> variables, IPrivacyProvider privacy, int maxMessageSize, ISnmpMessage report, SecurityModel securityModel)
         {
             if (variables == null)
             {
@@ -160,16 +224,25 @@ public GetBulkRequestMessage(VersionCode version, int messageId, int requestId,
 
             Version = version;
             Privacy = privacy ?? throw new ArgumentNullException(nameof(privacy));
-            Header = new Header(new Integer32(messageId), new Integer32(maxMessageSize), privacy.ToSecurityLevel() | Levels.Reportable);
+            Header = new Header(new Integer32(messageId), new Integer32(maxMessageSize), privacy.ToSecurityLevel() | Levels.Reportable, new Integer32((int)securityModel));
             var parameters = report.Parameters;
             var authenticationProvider = Privacy.AuthenticationProvider;
-            Parameters = new SecurityParameters(
-                parameters.EngineId,
-                parameters.EngineBoots,
-                parameters.EngineTime,
-                userName,
-                authenticationProvider.CleanDigest,
-                Privacy.Salt);
+
+            if (securityModel == SecurityModel.Tsm)
+            {
+                Parameters = SecurityParameters.Empty;
+            }
+            else
+            {
+                Parameters = new SecurityParameters(
+                    parameters.EngineId,
+                    parameters.EngineBoots,
+                    parameters.EngineTime,
+                    userName,
+                    authenticationProvider.CleanDigest,
+                    Privacy.Salt);
+            }
+
             var pdu = new GetBulkRequestPdu(
                 requestId,
                 nonRepeaters,
@@ -188,6 +261,24 @@ public GetBulkRequestMessage(VersionCode version, int messageId, int requestId,
             _bytes = this.PackMessage(null).ToBytes();
         }
 
+        /// <summary>
+        /// Creates a <see cref="GetBulkRequestMessage"/> with a specific <see cref="Sequence"/>.
+        /// </summary>
+        /// <param name="version">The version.</param>
+        /// <param name="messageId">The message id.</param>
+        /// <param name="requestId">The request id.</param>
+        /// <param name="userName">Name of the user.</param>
+        /// <param name="contextName">Context name.</param>
+        /// <param name="nonRepeaters">The non repeaters.</param>
+        /// <param name="maxRepetitions">The max repetitions.</param>
+        /// <param name="variables">The variables.</param>
+        /// <param name="privacy">The privacy provider.</param>
+        /// <param name="maxMessageSize">Size of the max message.</param>
+        /// <param name="report">The report.</param>
+        public GetBulkRequestMessage(VersionCode version, int messageId, int requestId, OctetString userName, OctetString contextName, int nonRepeaters, int maxRepetitions, IList<Variable> variables, IPrivacyProvider privacy, int maxMessageSize, ISnmpMessage report)
+            : this(version, messageId, requestId, userName, contextName, nonRepeaters, maxRepetitions, variables, privacy, maxMessageSize, report, SecurityModel.Usm)
+        { 
+        }
 
         /// <summary>
         /// Creates a <see cref="GetBulkRequestMessage"/> with a specific <see cref="Sequence"/>.

SharpSnmpLib/Messaging/GetNextRequestMessage.cs

@@ -92,6 +92,53 @@ public GetNextRequestMessage(VersionCode version, int messageId, int requestId,
         {
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GetNextRequestMessage"/> class.
+        /// </summary>
+        /// <param name="version">The version.</param>
+        /// <param name="messageId">The message id.</param>
+        /// <param name="requestId">The request id.</param>
+        /// <param name="contextName">Context name.</param>
+        /// <param name="variables">The variables.</param>
+        /// <param name="privacy">The privacy provider.</param>
+        /// <param name="maxMessageSize">Size of the max message.</param>
+        public GetNextRequestMessage(VersionCode version, int messageId, int requestId, OctetString contextName, IList<Variable> variables, IPrivacyProvider privacy, int maxMessageSize)
+        {
+            if (variables == null)
+            {
+                throw new ArgumentNullException(nameof(variables));
+            }
+
+            if (contextName == null)
+            {
+                throw new ArgumentNullException(nameof(contextName));
+            }
+
+            if (version != VersionCode.V3)
+            {
+                throw new ArgumentException("Only v3 is supported.", nameof(version));
+            }
+
+            if (privacy == null)
+            {
+                throw new ArgumentNullException(nameof(privacy));
+            }
+
+            Version = version;
+            Privacy = privacy;
+            Header = new Header(new Integer32(messageId), new Integer32(maxMessageSize), privacy.ToSecurityLevel() | Levels.Reportable, new Integer32((int)SecurityModel.Tsm));
+            Parameters = SecurityParameters.Empty;
+
+            var pdu = new GetNextRequestPdu(
+                requestId,
+                variables);
+            var contextEngineId = OctetString.Empty;
+            Scope = new Scope(contextEngineId, contextName, pdu);
+
+            Privacy.ComputeHash(Version, Header, Parameters, Scope);
+            _bytes = this.PackMessage(null).ToBytes();
+        }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="GetNextRequestMessage"/> class.
         /// </summary>
@@ -104,7 +151,8 @@ public GetNextRequestMessage(VersionCode version, int messageId, int requestId,
         /// <param name="privacy">The privacy provider.</param>
         /// <param name="maxMessageSize">Size of the max message.</param>
         /// <param name="report">The report.</param>
-        public GetNextRequestMessage(VersionCode version, int messageId, int requestId, OctetString userName, OctetString contextName, IList<Variable> variables, IPrivacyProvider privacy, int maxMessageSize, ISnmpMessage report)
+        /// <param name="securityModel">The security model</param>
+        public GetNextRequestMessage(VersionCode version, int messageId, int requestId, OctetString userName, OctetString contextName, IList<Variable> variables, IPrivacyProvider privacy, int maxMessageSize, ISnmpMessage report, SecurityModel securityModel)
         {
             if (variables == null)
             {
@@ -134,16 +182,25 @@ public GetNextRequestMessage(VersionCode version, int messageId, int requestId,
             Version = version;
             Privacy = privacy ?? throw new ArgumentNullException(nameof(privacy));
 
-            Header = new Header(new Integer32(messageId), new Integer32(maxMessageSize), privacy.ToSecurityLevel() | Levels.Reportable);
+            Header = new Header(new Integer32(messageId), new Integer32(maxMessageSize), privacy.ToSecurityLevel() | Levels.Reportable, new Integer32((int)securityModel));
             var parameters = report.Parameters;
             var authenticationProvider = Privacy.AuthenticationProvider;
-            Parameters = new SecurityParameters(
-                parameters.EngineId,
-                parameters.EngineBoots,
-                parameters.EngineTime,
-                userName,
-                authenticationProvider.CleanDigest,
-                Privacy.Salt);
+
+            if (securityModel == SecurityModel.Tsm)
+            {
+                Parameters = SecurityParameters.Empty;
+            }
+            else
+            {
+                Parameters = new SecurityParameters(
+                    parameters.EngineId,
+                    parameters.EngineBoots,
+                    parameters.EngineTime,
+                    userName,
+                    authenticationProvider.CleanDigest,
+                    Privacy.Salt);
+            }
+
             var pdu = new GetNextRequestPdu(
                 requestId,
                 variables);
@@ -160,6 +217,22 @@ public GetNextRequestMessage(VersionCode version, int messageId, int requestId,
             _bytes = this.PackMessage(null).ToBytes();
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GetNextRequestMessage"/> class.
+        /// </summary>
+        /// <param name="version">The version.</param>
+        /// <param name="messageId">The message id.</param>
+        /// <param name="requestId">The request id.</param>
+        /// <param name="userName">Name of the user.</param>
+        /// <param name="contextName">Context name.</param>
+        /// <param name="variables">The variables.</param>
+        /// <param name="privacy">The privacy provider.</param>
+        /// <param name="maxMessageSize">Size of the max message.</param>
+        /// <param name="report">The report.</param>
+        public GetNextRequestMessage(VersionCode version, int messageId, int requestId, OctetString userName, OctetString contextName, IList<Variable> variables, IPrivacyProvider privacy, int maxMessageSize, ISnmpMessage report)
+            : this(version, messageId, requestId, userName, contextName, variables, privacy, maxMessageSize, report, SecurityModel.Usm)
+        { 
+        }
 
         /// <summary>
         /// Initializes a new instance of the <see cref="GetNextRequestMessage"/> class.