Extracting current ASP.NET machine keys and setting them without committing them to the Web.config

MachineKeys.cs

namespace MyApp.Web.Security
{
    using System;
    using System.Configuration;
    using System.Reflection;
    using System.Web;
    using System.Web.Configuration;

    public class MachineKeys
    {
        public MachineKeys(string encryptionKey, string validationKey)
        {
            this.EncryptionKey = encryptionKey;
            this.ValidationKey = validationKey;
        }

        public string EncryptionKey { get; }

        public string ValidationKey { get; }

        public static MachineKeys Extract()
        {
            var assembly = typeof(HttpRuntime).Assembly; // s_autogenKeys
            var typeMKMKP = assembly.GetType("System.Web.Security.Cryptography.MachineKeyMasterKeyProvider");
            var typeCK = assembly.GetType("System.Web.Security.Cryptography.CryptographicKey");
            var typeCU = assembly.GetType("System.Web.Security.Cryptography.CryptoUtil");
            var config = new MachineKeySection();

            var mkmkp = assembly.CreateInstance(typeMKMKP.FullName, false, BindingFlags.Instance | BindingFlags.NonPublic, null, new object[] { config, null, null, null, null }, null, null);

            var encKey = typeMKMKP.GetMethod("GetEncryptionKey").Invoke(mkmkp, Array.Empty<object>());
            var valKey = typeMKMKP.GetMethod("GetValidationKey").Invoke(mkmkp, Array.Empty<object>());

            var methodGetKeyMaterial = typeCK.GetMethod("GetKeyMaterial");
            Func<object, byte[]> getKeyMaterial = k => (byte[])methodGetKeyMaterial.Invoke(k, Array.Empty<object>());

            var methodBinaryToHex = typeCU.GetMethod("BinaryToHex");
            Func<byte[], string> binaryToHex = d => (string)methodBinaryToHex.Invoke(null, new object[] { d });

            return new MachineKeys(
                binaryToHex(getKeyMaterial(encKey)),
                binaryToHex(getKeyMaterial(valKey)));
        }

        public static void InstallKeysFromAppSettings()
        {
            Install(GetKeysFromAppSettings());
        }

        public static void Install(MachineKeys keys)
        {
            if (keys == null)
            {
                return;
            }

            var getter = typeof(MachineKeySection).GetMethod("GetApplicationConfig", BindingFlags.Static | BindingFlags.NonPublic);
            var config = (MachineKeySection)getter.Invoke(null, Array.Empty<object>());

            var readOnlyField = typeof(ConfigurationElement).GetField("_bReadOnly", BindingFlags.Instance | BindingFlags.NonPublic);
            readOnlyField.SetValue(config, false);

            config.DecryptionKey = keys.EncryptionKey;
            config.ValidationKey = keys.ValidationKey;

            readOnlyField.SetValue(config, true);
        }

        public static MachineKeys GetKeysFromAppSettings()
        {
            var encKey = ConfigurationManager.AppSettings["machineDecryptionKey"];
            if (string.IsNullOrEmpty(encKey))
            {
                return null;
            }

            var valKey = ConfigurationManager.AppSettings["machineValidationKey"];
            if (string.IsNullOrEmpty(valKey))
            {
                return null;
            }

            return new MachineKeys(encKey, valKey);
        }
    }
}