JSON Data Masking Framework

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

Disclaimer

For .NET Core applications, you can use the original JSON Data Masking library whose repository is this one.

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.

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

Support

This library supports masking of string fields only, although it also supports List<string>/IEnumerable<string> and Dictionary<string, string>. Nested class properties are also masked, independently of depth.

Property Type	Support
string	✅
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	❌
Any other base type different from string	❌

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