Documentation regarding GoogleAuthenticatorRedux. Official documentation of the library can be found at https://www.craftblue.com/projects/php/google-authenticator-2fa

client-usage.php

<?php

// if you are using composer, which is the preferred method of autoloading 
require_once('./vendor/autoload.php');

// create a new secret for a user wishing to enable 2FA
// you will need to store this securely
$secret = $ga->createSecret();

// example of generating a QR code to display to the end user 
// note that you need to generate a unique label for each user
// in the format of your application or vendor name (a namespace/prefix)
// followed by a colon, followed by a unique identifier for the user such
// as their login email address to your app or their name
$qrCodeUrl = $ga->getQRCodeUrl('MyVendorPrefix:userlogin@gmail.com', $secret);
echo '<img src="' . $qrCodeUrl . '" />';

// retrieve an example valid code
// (usually the user would supply this for you from the Google Authenticator app) 
$code = $ga->getCode($secret);

// example of verifying that a code is valid for the secret at this given time 
if ($ga->verifyCode($secret, $code, 2)) {
    echo 'VERIFIED';
} else {
    echo 'VERIFICATION FAILED';
}

init-client.php

<?php

require 'vendor/autoload.php';

$client = new CraftBlue\GoogleAuthenticator();

install-composer.sh

# install composer if you don't already have it on your machine
curl -sS https://getcomposer.org/installer | php

# from your project's base directory, run the composer command to install GoogleAuthenticator
php composer.phar require craftblue/google-authenticator-redux

run-tests.sh

# if you have phpunit globally, run this from the base project directory:
phpunit 

# after updating composer, run this from the base project directory:
vendor/bin/phpunit