JsonConverter Obfuscator

ObfuscatorConverter.cs

public class ObfuscatorConverter : JsonConverter
    {
        private readonly IEnumerable<Type> _types;
        private readonly int _charsToShow;
        private readonly char _obfuscateChar;

        public ObfuscatorConverter() : this(2, '*')
        {
        }

        public ObfuscatorConverter(int charsToShow = 2, char obfuscateChar = '*')
        {
            _types = new List<Type>
                     {
                             typeof(string),
                             typeof(Guid)
                     };
            _charsToShow = charsToShow;
            _obfuscateChar = obfuscateChar;
        }

        public override bool CanConvert(Type objectType)
        {
            return _types.Any(t => t == objectType);
        }

        public override bool CanWrite => true;

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            if (value != null)
            {
                var currentValue = value.ToString();
                if (!string.IsNullOrWhiteSpace(currentValue))
                {
                    //encode the string
                    var array = currentValue.ToCharArray();
                    var stopIndex = array.Length - _charsToShow;

                    for (var i = 0; i < array.Length; i++)
                    {
                        if (i < stopIndex)
                        {
                            array[i] = _obfuscateChar;
                        }
                    }
                    var newValue = new string(array);
                    writer.WriteValue(newValue);
                }
            }
        }

        public override bool CanRead => false;

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }
    }