README

A Laravel Package to generate cryptographically-secure pseudorandom PINs (personal identification numbers).

Target Features:

• Each PIN comprises four numeric digits (e.g. "2845")
• "Obvious" numbers should not be allowed (e.g. "1111", "1234")
• PINs should be generated in apparently random order
• A PIN should not be repeated until all preceding valid PINs have been emitted - even if the program is restarted between PINs.

Achieved Features:

• Each PIN comprises four numeric digits (e.g. "2845"): this is fulfilled by ensuring that each generated PIN is formatted as a 4-digit string.
• "Obvious" numbers should not be allowed (e.g. "1111", "1234"): this is satisfied by checking generated PINs against a pre-specified list of obvious numbers.
• PINs should be generated in apparently random order: this is satisfied by the usage of PHP's random_int() function (which generates cryptographically secure pseudo-random integers).
• A PIN should not be repeated until all preceding valid PINs have been emitted - This is ensured by making use of a Database. Whenever a new PIN is to be generated, the database is checked to see if all valid PINs have been generated. If yes, the database is reset. Otherwise, the database is checked for the newly generated PIN, if it already exists, the database is checked for preceding valid PINs. If all preceding valid PINs have been emitted, emit the generated PIN. Otherwise, a new PIN is generated and the check is performed over again.

Installation

To install PIN Generator package, run:

composer require faaizz/pin_generator

Autoloading

To automatically register the package with a Laravel project, the PinGeneratorServiceProvider can be added under extra->laravel->providers in composer.json as shown below:

...
"extra": {
    "laravel" : {
        "providers": [
            ...
            "Faaizz\\PinGenerator\\PinGeneratorServiceProvider"
            ...
        ]
    }
}

The service provider can also be manually registered in the Laravel project's app/config/app.php as:

<?php
...
'providers' => [
    ...
    Faaizz\PinGenerator\PinGeneratorServiceProvider::class
],
...

Migration

The database migrations can be run by executing database migration in the Laravel project:

php artisan migrate

Facade

The Generator facade can be used from the Faaizz\PinGenerator\Facades namespace after the PinGeneratorServiceProvider has been registered with a Laravel project.

Usage

Easily generate PINs by calling the generatePin() method on the Generator facade:

use Faaizz\PinGenerator\Facades\Generator;
...
$pin = Generator::generatePin();

Configuration

Publish

To publish package configs into a Laravel project, run:

php artisan vendor:publish --provider="Faaizz\PinGenerator\PinGeneratorServiceProvider" --tag="config"

This publishes the config into app/config/pingenerator.php.

Customization

To configure the package, edit app/config/pingenerator.php in Laravel project appropriately.

• Change number of digits: To change the number of digits of generated PINs, map the desired value to the digit key. For example, to generate 10-digit PINs:

// config/config.php
return [
    'digits' => 10
    ...
];

• Add/Remove Obvious Number: To add/remove "obvious" numbers, edit the mapped value of obvious_numbers as required:

// config/config.php
return [
    ...
    'obvious_numbers' => [
        0000, 1111, 2222, 3333, 4444, 5555, 6666, 7777,
        8888, 9999, 1234, 5678, 1010, 2020
    ]
];

Testing

Run tests by executing:

# Note: composer install must have been run to install dependencies
./execTests.sh

References

• Cryptographically-secure pseudorandom number generator - Wikipedia