using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

using System.Collections.ObjectModel;

using System.Runtime.Serialization;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

using Microsoft.VisualStudio.TestTools.UnitTesting;

​

using Microsoft.Research.SEAL;

​

using Debug = System.Console;

​

//https://stackoverflow.com/questions/60172952/cannot-deserialise-json-to-type-unable-to-find-constructor

​

    public class CiphertextConverter : JsonConverter<Ciphertext>

    {

        readonly SEALContext context;

        public CiphertextConverter(SEALContext context) => this.context = context ?? throw new ArgumentNullException(nameof(context));

        public override Ciphertext ReadJson(JsonReader reader, Type objectType, Ciphertext existingValue, bool hasExistingValue, JsonSerializer serializer)

        {

            var data = serializer.Deserialize<byte []>(reader);

            if (data == null)

                return null;

            var cipherText = new Ciphertext();

            using (var stream = new MemoryStream(data))

                cipherText.Load(context, stream);

            return cipherText;

        }

​

        public override void WriteJson(JsonWriter writer, Ciphertext value, JsonSerializer serializer)

        {

            using (var stream = new MemoryStream())

            {

                value.Save(stream, ComprModeType.Deflate); // TODO: test to see whether Deflate gives better size vs speed performance in practice.

                writer.WriteValue(stream.ToArray());

            }

        }

    }

​

    [DataContract]

    public class sampleClass

    {

        [DataMember]

        public Ciphertext ciphertext { get; set; }

​

        public sampleClass() { }

    } 

​

    public class TestClass

    {

        [TestMethod]

        public void JsonNetSaveLoadTest()

        {

            Debug.WriteLine("Testing Json.NET");

            Func<Ciphertext, SEALContext, Ciphertext> roundtrip = (cipher, context) =>

            {

                var clientArray = new [] { new sampleClass { ciphertext = cipher } };

​

                var settings = new JsonSerializerSettings

                {

                    Converters = { new CiphertextConverter(GlobalContext.Context) },

                };

                var requestBody = JsonConvert.SerializeObject(clientArray, settings);

                Debug.Write("   ");

                Debug.WriteLine(requestBody);

                Debug.WriteLine("   requestBody.Length={0}", requestBody.Length);

                var array = JsonConvert.DeserializeObject<sampleClass []>(requestBody, settings);

                Assert.IsTrue(array.Length == clientArray.Length);

                var reserializedJson = JsonConvert.SerializeObject(array, settings);

                Debug.Write("   ");

                Debug.WriteLine(reserializedJson);

                Assert.IsTrue(requestBody == reserializedJson);

​

                return array[0].ciphertext;

            };

            SaveLoadTest(roundtrip);

            Console.WriteLine("   passed.");

        }

        // Adapted from https://github.com/microsoft/SEAL/blob/master/dotnet/tests/CiphertextTests.cs#L113

        [TestMethod]

        public void DirectSaveLoadTest()

        {

            Debug.WriteLine("Testing direct save and load:");

            Func<Ciphertext, SEALContext, Ciphertext> roundtrip = (cipher, context) =>

            {

                Ciphertext loaded = new Ciphertext();

​

                Assert.AreEqual(0ul, loaded.Size);

                Assert.AreEqual(0ul, loaded.PolyModulusDegree);

                Assert.AreEqual(0ul, loaded.CoeffModCount);

​

                using (MemoryStream mem = new MemoryStream())

                {

                    cipher.Save(mem);

​

                    mem.Seek(offset: 0, loc: SeekOrigin.Begin);

​

                    loaded.Load(context, mem);

                }

                return loaded;

            };

            SaveLoadTest(roundtrip);

            Debug.WriteLine("   passed.");

        }

        // Adapted from https://github.com/microsoft/SEAL/blob/master/dotnet/tests/CiphertextTests.cs#L113

        static void SaveLoadTest(Func<Ciphertext, SEALContext, Ciphertext> roundtrip)

        {

            SEALContext context = GlobalContext.Context;

            KeyGenerator keygen = new KeyGenerator(context);

            Encryptor encryptor = new Encryptor(context, keygen.PublicKey);

            Plaintext plain = new Plaintext("2x^3 + 4x^2 + 5x^1 + 6");

            Ciphertext cipher = new Ciphertext();

​

            encryptor.Encrypt(plain, cipher);

​

            Assert.AreEqual(2ul, cipher.Size);

            Assert.AreEqual(8192ul, cipher.PolyModulusDegree);

            Assert.AreEqual(4ul, cipher.CoeffModCount);

​

            var loaded = roundtrip(cipher, context);

            Assert.AreEqual(2ul, loaded.Size);

            Assert.AreEqual(8192ul, loaded.PolyModulusDegree);

            Assert.AreEqual(4ul, loaded.CoeffModCount);

            Assert.IsTrue(ValCheck.IsValidFor(loaded, context));

​

            ulong ulongCount = cipher.Size * cipher.PolyModulusDegree * cipher.CoeffModCount;

            for (ulong i = 0; i < ulongCount; i++)

            {

                Assert.AreEqual(cipher[i], loaded[i]);

            }

        }

    }

​

    static class GlobalContext

    {

        // Copied from https://github.com/microsoft/SEAL/blob/master/dotnet/tests/GlobalContext.cs

        static GlobalContext()

        {

            EncryptionParameters encParams = new EncryptionParameters(SchemeType.BFV)

            {

                PolyModulusDegree = 8192,

                CoeffModulus = CoeffModulus.BFVDefault(polyModulusDegree: 8192)

            };

            encParams.SetPlainModulus(65537ul);

            BFVContext = new SEALContext(encParams);

​

            encParams = new EncryptionParameters(SchemeType.CKKS)

            {

                PolyModulusDegree = 8192,

                CoeffModulus = CoeffModulus.BFVDefault(polyModulusDegree: 8192)

            };

            CKKSContext = new SEALContext(encParams);

        }

​

        public static SEALContext BFVContext { get; private set; } = null;

        public static SEALContext CKKSContext { get; private set; } = null;

        public static SEALContext Context => BFVContext;

    }

​

    public class Program

    {

        public static void Main()

        {

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

            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine("Microsoft.Research.SEAL version: " + typeof(SEALContext).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                new TestClass().DirectSaveLoadTest();

                new TestClass().JsonNetSaveLoadTest();

                Console.WriteLine("All tests passed.");

            }

            catch (Exception ex)

            {

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

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.CodeBase.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​