README.md

Masking

A small library creates to add masking to instance variables when serializing an class to a string. This is especially useful in the following cases:

• When persisting information that may be deemed sensitive, but not critical for support / troubleshooting, to a log file.
• When we more interested in the fact that a value was received, but persisting the value will just cause bloat (i.e. if we receive an image in base64 format).

NOTE:

• Masking is not reversable!
• Masking is applied on serialization and DOES NOT change the value stored in the instance variable!

Supported Masking Methods:

The following masking methods are supported:

Mask

Masks a string based on a specified regular expression pattern.

For example, the following implementation will replace all characters between the first 3 and last 3 values of a string, hence "12345678900987654321" will become "123XXXXXXXXXXXXXX321"

[Mask(MaskingMethod.Mask, @"(?<=.{3}).+(?=.{3})")]
public string ContactNumber { get; set; }

Replace

Replaces a string with the specified string.

For example, the following implemenation will replace the entire string, hence "12345678900987654321" will become "REPLACED"

[Mask(MaskingMethod.Replace, @"REPLACED")]
public string ContactNumber { get; set; }

Trim

Trims a string based on a specified regular expression pattern. The characters "..." will be inserted to indicate the trimmed string.

For example, the following implementation will trim all characters between the first 3 and last 3 values of a string, hence "12345678900987654321" will become "123...321"

[Mask(MaskingMethod.Trim, @"(?<=.{3}).+(?=.{3})")]
public string ContactNumber { get; set; }

Example:

Define a Person object with masks:

[Mask]
public class Person
{
	public string Name { get; set; }
	public string Surname { get; set; }

	[Mask(MaskingMethod.Mask, @"(?<=.{3}).+(?=.{3})")]
	public string ContactNumber { get; set; }

	[Mask(MaskingMethod.Mask, @"(?<=.{1}).+(?<=@)")]
	public string Email { get; set; }
			
	[Mask(MaskingMethod.Trim, @"(?<=.{6}).+(?=.{6})")]
	public string Address { get; set; }
			
	[Mask(MaskingMethod.Replace, @"REPLACED")]
	public string IdentityNumber { get; set; }
}

Now give it some values:

Person MaskedPerson = new Person()
{
	Name = "John",
	Surname = "Smith",
	ContactNumber = "0991231234",
	Email = "john.smith@testdomain.com",
	Address = "59 Hornbill Avenue, South Crater, Mars, 000345",
	IdentityNumber = "1234567890123"
};

Direct Serializing:

JsonConvert.SerializeObject(MaskedPerson);

outputs:

{"Name":"John","Surname":"Smith","ContactNumber":"0991231234","Email":"john.smith@testdomain.com","Address":"59 Hornbill Avenue, South Crater, Mars, 000345","IdentityNumber":"1234567890123"}

Serializing when applying the Mask:

new MaskedType<Person>(MaskedPerson).Serialize();

outputs:

{"Name":"John","Surname":"Smith","ContactNumber":"099XXXX234","Email":"jXXXXXXXXXXtestdomain.com","Address":"59 Hor...000345","IdentityNumber":"REPLACED"}