added UWP compiler flags

Source/MQTTnet.Extensions.WebSocket4Net/WebSocket4NetMqttChannel.cs

@@ -85,7 +85,12 @@ namespace MQTTnet.Extensions.WebSocket4Net
             {
                 foreach (var certificate in _webSocketOptions.TlsOptions.Certificates)
                 {
+#if WINDOWS_UWP
+                    certificates.Add(new X509Certificate(certificate));
+#else
                     certificates.Add(certificate);
+#endif
+                    
                 }
             }
 

Source/MQTTnet/Client/Options/MqttClientOptionsBuilder.cs

@@ -256,7 +256,11 @@ namespace MQTTnet.Client.Options
                         UseTls = true,
                         SslProtocol = _tlsParameters.SslProtocol,
                         AllowUntrustedCertificates = _tlsParameters.AllowUntrustedCertificates,
+#if WINDOWS_UWP
+                        Certificates = _tlsParameters.Certificates?.Select(c => c.ToArray()).ToList(),
+#else
                         Certificates = _tlsParameters.Certificates?.ToList(),
+#endif
                         CertificateValidationCallback = _tlsParameters.CertificateValidationCallback,
                         IgnoreCertificateChainErrors = _tlsParameters.IgnoreCertificateChainErrors,
                         IgnoreCertificateRevocationErrors = _tlsParameters.IgnoreCertificateRevocationErrors

Source/MQTTnet/Client/Options/MqttClientOptionsBuilderTlsParameters.cs

@@ -18,7 +18,12 @@ namespace MQTTnet.Client.Options
 
         public SslProtocols SslProtocol { get; set; } = SslProtocols.Tls12;
 
+#if WINDOWS_UWP
+        public IEnumerable<IEnumerable<byte>> Certificates { get; set; }
+#else
         public IEnumerable<X509Certificate> Certificates { get; set; }
+#endif
+        
 
         public bool AllowUntrustedCertificates { get; set; }
 

Source/MQTTnet/Client/Options/MqttClientTlsOptions.cs

@@ -15,8 +15,11 @@ namespace MQTTnet.Client.Options
         public bool IgnoreCertificateChainErrors { get; set; }
 
         public bool AllowUntrustedCertificates { get; set; }
-
+#if WINDOWS_UWP
+        public List<byte[]> Certificates { get; set; }
+#else
         public List<X509Certificate> Certificates { get; set; }
+#endif
 
         public SslProtocols SslProtocol { get; set; } = SslProtocols.Tls12;
 

Source/MQTTnet/Implementations/MqttTcpChannel.Uwp.cs

@@ -132,7 +132,7 @@ namespace MQTTnet.Implementations
                 throw new NotSupportedException("Only one client certificate is supported for UWP.");
             }
 
-            return new Certificate(options.TlsOptions.Certificates.First().GetRawCertData());
+            return new Certificate(options.TlsOptions.Certificates.First().AsBuffer());
         }
 
         private IEnumerable<ChainValidationResult> ResolveIgnorableServerCertificateErrors()

Source/MQTTnet/Implementations/MqttWebSocketChannel.cs

@@ -84,7 +84,12 @@ namespace MQTTnet.Implementations
                 clientWebSocket.Options.ClientCertificates = new X509CertificateCollection();
                 foreach (var certificate in _options.TlsOptions.Certificates)
                 {
+#if WINDOWS_UWP
+                    clientWebSocket.Options.ClientCertificates.Add(new X509Certificate(certificate));
+#else
                     clientWebSocket.Options.ClientCertificates.Add(certificate);
+#endif
+                    
                 }
             }