Masking Engine

A PHP masking engine, that allows you to quickly and easily mask data based on configured formats.

Installation

You can install this package using composer

composer require juststeveking/masking-engine

Configuration

You can publish the configuration for this package using the php artisan vendor:publish --tag=masking-config

This will publish the default config to config/masking.php, and will look like the following by default:

use JustSteveKing\Masking\Matchers\StringMatcher;

return [
    'values' => [
        'password' => StringMatcher::class,
    ],
];

Usage

Let's walk through the usage. We have a values array, that hold how we want to mask data in our application.

You will see that we are using a StringMatcher here, what this can do is obfuscate any string to a series of *.

For example test will turn into ****. By default, this package comes with a selection of maskers/matchers that you can use - but you are also free to create your own.

• StringMatcher - will match or mask a standard string.
• CreditCard - will match or mask a credit card number from 1234-1234-1234-1234 to ****-****-****-1234.
• Date - will match or mask a date from 09/09/1988 to 09/09/****.
• Email - will match or mask an email address from juststevemcd@gmail.com to ************@gmail.com.
• PostalCode - will match or mask a UK postal code from B33 8TH to B33 ***.
• SocialSecurity - will match or mask a Social Security Number from 123-45-6789 to ***-**-6789.

Please note, these classes will not validate that the data is correct - for example it will not validate it is a correct credit card number or social security number.

The Masking Engine uses Regex to define a pattern both mask or match the input passed in. All Matching classes needs to either implement the MasksInput interface, or extend the StringMatcher class itself.

Let's look at the Email matcher as an example:

final class Email extends StringMatcher
{
    protected string $pattern = '/^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/';

    public function mask(): string
    {
        return (string) preg_replace_callback(
            pattern: '/([^@]+)/',
            callback: static fn(array $matches): string => str_repeat(
                string: '*',
                times: mb_strlen($matches[0]),
            ),
            subject: $this->input,
            limit: 1,
        );
    }
}

We define a pattern as a property for the class, which is a simple Regex to make sure that the input is formatted correctly. The masking method, will do a preg replace callback to take certain parts from the input and mask a specific part of the input.

In theory, you don't have to use Regex at all. You could implement something really simple such as:

use JustSteveKing\Masking\Matchers\StringMatcher;

final class Dummy extends StringMatcher
{
    public function mask(): string
    {
        return '<DUMMY VALUE>';
    }
}

The only important part of the class, is that the mask method will return a string.

Testing

This package comes will a full test suite, as well as static analysis checks:

composer test

or

composer stan

Contributing

Feel free to use this package as suits your needs, if you would like to contribute please make sure that you are following the coding standards in place for this library, and test coverage is kept to a high standard.

Security

If you find any security related issues with this package, please feel free to reach out to me directly.