using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.IO;

using System.Data;

using System.Globalization;

​

using System.Xml;

using System.Xml.Serialization;

using System.Xml.Linq;

​

using System.Runtime.Serialization;

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/74762472/issue-with-wcf-type-serialization

​

    [DataContract]

    public class RefDomain

    {

        private string name;

        private RefDomain parent;

        private Type entityType;

​

        [DataMember]

        public string Name

        {

            get => this.name;

            protected set => this.name = value;

        }

​

        [DataMember]

        public RefDomain Parent

        {

              get => this.parent;

              protected set => this.parent = value;

        }

​

        public Type RefEntityType

        {

              get => this.entityType;

              protected set => this.entityType = value;

        }

​

        [DataMember(Name = "RefEntityType")]

        string RefEntityTypeString 

        {

            get

            {

                return RefEntityType?.FullName;

            }

            set

            {

                // Note that simply deserializing a type supplied over the wire will make your application vulnerable to type injection attacks,

                // in which an attacker tricks you into constructing a type that effects an attack when constructed, deserialized or disposed.  

                // This is a known vulnerability with Json.NET's TypeNameHandling.None.  See for details

                // https://www.blackhat.com/docs/us-17/thursday/us-17-Munoz-Friday-The-13th-JSON-Attacks-wp.pdf

                // https://stackoverflow.com/questions/39565954/typenamehandling-caution-in-newtonsoft-json/

                // https://stackoverflow.com/questions/49038055/external-json-vulnerable-because-of-json-net-typenamehandling-auto

                var type = value == null ? null : Type.GetType(value);

                // Check the type against a whitelist here?

                RefEntityType = type;

            }

        }

        // Your class was had no way to set the protected properties, so I added a parameterized constructor.

        public RefDomain() { }

        public RefDomain(string name, RefDomain parent, Type entityType) => (this.name, this.parent, this.entityType) = (name, parent, entityType);

    }

​

    class TestClass

    {

        public static void Test()

        {

            var d = new RefDomain("foo", null, typeof(string));

            var xml = d.ToContractXml();

            Console.WriteLine(xml);

            var d2 = DataContractSerializerHelper.FromContractXml<RefDomain>(xml);

            Assert.AreEqual(d.Name, d2.Name);

            Assert.AreEqual(d.Parent, d2.Parent);

            Assert.AreEqual(d.RefEntityType, d2.RefEntityType);

        }   

    }

​

    public static partial class DataContractSerializerHelper

    {

        public static string ToContractXml<T>(this T obj, DataContractSerializer serializer = null, XmlWriterSettings settings = null)

        {

            serializer = serializer ?? new DataContractSerializer(obj == null ? typeof(T) : obj.GetType());

            using (var textWriter = new StringWriter())

            {

                settings = settings ?? new XmlWriterSettings { Indent = true };

                using (var xmlWriter = XmlWriter.Create(textWriter, settings))

                {

                    serializer.WriteObject(xmlWriter, obj);

                }

                return textWriter.ToString();

            }

        }

​

        public static T FromContractXml<T>(string xml, DataContractSerializer serializer = null)

        {

            using (var textReader = new StringReader(xml ?? ""))

            using (var xmlReader = XmlReader.Create(textReader))

            {

                return (T)(serializer ?? new DataContractSerializer(typeof(T))).ReadObject(xmlReader);

            }

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1}), {2}", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , Environment.Version, Environment.OSVersion);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​