Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.ServiceModel/System/ServiceModel/Security/SecurityKeyEntropyMode.cs

@@ -0,0 +1,34 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace System.ServiceModel.Security
+{
+    using System.ComponentModel;
+
+    public enum SecurityKeyEntropyMode
+    {
+        ClientEntropy,
+        ServerEntropy,
+        CombinedEntropy
+    }
+
+    sealed class SecurityKeyEntropyModeHelper
+    {
+        internal static bool IsDefined(SecurityKeyEntropyMode value)
+        {
+            return (value == SecurityKeyEntropyMode.ClientEntropy
+                || value == SecurityKeyEntropyMode.ServerEntropy
+                || value == SecurityKeyEntropyMode.CombinedEntropy);
+        }
+
+        internal static void Validate(SecurityKeyEntropyMode value)
+        {
+            if (!IsDefined(value))
+            {
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new InvalidEnumArgumentException("value", (int)value,
+                    typeof(SecurityKeyEntropyMode)));
+            }
+        }
+    }
+}