Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel/System/ServiceModel/ComIntegration/MessageUtil.cs

@@ -0,0 +1,70 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+namespace System.ServiceModel.ComIntegration
+{
+    using System;
+    using System.IdentityModel.Claims;
+    using System.IdentityModel.Policy;
+    using System.Security.Permissions;
+    using System.Security.Principal;    
+    using System.ServiceModel;
+    using System.ServiceModel.Channels;
+    using System.ServiceModel.Security;
+    using System.Transactions;
+    using System.ServiceModel.Transactions;
+    using System.ServiceModel.Diagnostics;
+    using System.EnterpriseServices;
+
+    static class MessageUtil
+    {
+        public static WindowsIdentity GetMessageIdentity(Message message)
+        {
+            WindowsIdentity callerIdentity = null;
+
+            SecurityMessageProperty securityProp;
+            securityProp = message.Properties.Security;
+            if (securityProp != null)
+            {
+                ServiceSecurityContext context;
+                context = securityProp.ServiceSecurityContext;
+                if (context != null)
+                {
+                    if (context.WindowsIdentity == null)
+                    {
+                        throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(Error.RequiresWindowsSecurity());
+                    }
+
+                    callerIdentity = context.WindowsIdentity;
+                }
+            }
+
+            if ((callerIdentity == null) || (callerIdentity.IsAnonymous))
+            {
+                // No security, no identity, must be anonymous.
+                callerIdentity = SecurityUtils.GetAnonymousIdentity();
+            }
+
+            return callerIdentity;
+        }
+
+        // The demand is not added now (in 4.5), to avoid a breaking change. To be considered in the next version.
+        /*
+        [PermissionSet(SecurityAction.Demand, Unrestricted = true)] // because we call code from a non-APTCA assembly; transactions are not supported in partial trust, so customers should not be broken by this demand
+        */
+        public static Transaction GetMessageTransaction(Message message)
+        {
+            ServiceConfig serviceConfig = new ServiceConfig();
+            serviceConfig.Transaction = TransactionOption.Disabled;
+            ServiceDomain.Enter( serviceConfig );
+            try
+            {
+                return TransactionMessageProperty.TryGetTransaction(message);
+            }
+            finally
+            {
+                ServiceDomain.Leave();
+            }
+        }
+    }
+}