Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.ServiceModel/System/ServiceModel/DnsEndpointIdentity.cs

@@ -0,0 +1,44 @@
+//----------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace System.ServiceModel
+{
+    using System;
+    using System.IdentityModel.Claims;
+    using System.IdentityModel.Policy;
+    using System.Xml;
+    using System.Xml.Serialization;
+
+    public class DnsEndpointIdentity : EndpointIdentity
+    {
+        public DnsEndpointIdentity(string dnsName)
+        {
+            if (dnsName == null)
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("dnsName");
+
+            base.Initialize(Claim.CreateDnsClaim(dnsName));
+        }
+
+        public DnsEndpointIdentity(Claim identity)
+        {
+            if (identity == null)
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("identity");
+
+            // PreSharp Bug: Parameter 'identity.ResourceType' to this public method must be validated: A null-dereference can occur here.
+#pragma warning suppress 56506 // Claim.ClaimType will never return null
+            if (!identity.ClaimType.Equals(ClaimTypes.Dns))
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgument(SR.GetString(SR.UnrecognizedClaimTypeForIdentity, identity.ClaimType, ClaimTypes.Dns));
+
+            base.Initialize(identity);
+        }
+
+        internal override void WriteContentsTo(XmlDictionaryWriter writer)
+        {
+            if (writer == null)
+                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("writer");
+
+            writer.WriteElementString(XD.AddressingDictionary.Dns, XD.AddressingDictionary.IdentityExtensionNamespace, (string)this.IdentityClaim.Resource);
+        }
+    }
+}