JSON Data Masking

JSON Data Masking is a library for .NET Core applications that simplifies the masking process of PII/sensitive information.

Usage

After installing the Nuget package in your project, you need to take the following steps:

1. Add the [SensitiveData] attribute in your class properties to indicate what should be masked, and use its available fields to configure the masking:

   • PreserveLength: Set to true to keep the property length when masking its value. By default this setting is set to false.
   • ShowFirst: If set, shows the first N characters of the property, not masking them. The default value is 0.
   • ShowLast: If set, shows the last N characters of the property, not masking them. The default value is 0.
   • SubstituteText: If set, the entire property value will be override with this text. Note that using this setting will ignore all other settings.
   • Mask: Set to a character to use it when masking the property's value. By default, the character * is used.

   PS.: These customization fields only work for fields with a string base type.

2. Call the JsonMask.MaskSensitiveData() function, passing in your object instance as a parameter.

Support

Base Types

This library supports masking of the following base types:

• string fields, which are masked following the rules detailed in the Usage section.
• Other types such as bool, (s)byte, (u)short, (u)int, (u)long, float, double, decimal, char, Datetime, DatetimeOffset, and Guid, which are set to their respective default values when having the [SensitiveData] attribute.
• Any other base types are currently NOT supported.

Collections

The library also supports the masking of some collections, such as:

• List<T>, where T is a class or string.
• IEnumerable<T>, where T is a class or string.
• Dictionary<string, string>.
• Any other collection type, such as Array, ArrayList<T>, etc., is NOT supported.

Nested class fields

Nested class properties are also masked, independently of depth.

Examples

Attributes

public class PropertiesExamples { /// 123456789 results in "*****" [SensitiveData] public string DefaultMask { get; set; } /// 123456789 results in "REDACTED" [SensitiveData(SubstituteText = "REDACTED")] public string SubstituteMask { get; set; } /// 123456789 results in "123*****789" [SensitiveData(ShowFirst = 3, ShowLast = 3)] public string ShowCharactersMask { get; set; } /// 123456789 results in "#########" [SensitiveData(PreserveLength = true, Mask = "#")] public string PreserveCustomMask { get; set; } }

Functions

var maskedData = JsonMask.MaskSensitiveData(data);

Dependencies

• DeepCloner