Custom OAuth2 user database - php

Question

I'm currently implementing OAuth2 in my website to keep an user logged in inside an Android app. I want to change the default OAuth2 user database to my own user database. Unfortunately I can't find out how to do that. It should be possible with overriding classes and without changing the code in the core library, but how to do it?
This is what I have in my server.php file:
// Autoloading (composer is preferred, but for this example let's just do this)
require_once('/src/OAuth2/Autoloader.php');
OAuth2\Autoloader::register();
$storage = new OAuth2\Storage\Pdo(array('dsn' => 'mysql:host=xxxx;dbname=xxxx', 'username' => 'xxxx', 'password' => 'xxxx'));
// Pass a storage object or array of storage objects to the OAuth2 server class
$server = new OAuth2\Server($storage);
// Add the "Password / User Credentials" grant type
$server->addGrantType(new OAuth2\GrantType\UserCredentials($storage));
So here I want to use to my own user table instead of the default oauth_users table. And because the passwords are salted I need to have a different password check too. I am using the BShaffer OAuth2 Library: https://github.com/bshaffer/oauth2-server-php

Answer 1

With this library it's easy to write custom code so you don't have to touch the core of this library.
For this problem you'll have to create a custom storage class that implements the UserCredentialsInterface. There are two methods in here which you need to implement yourself
public function checkUserCredentials()
public function getUserDetails()
Here you can implement your logic for checking user details and fetching user details.
After this you'll need to add this storage to the oAuth server like this:
$server = new OAuth2\Server($storage);
$userStorage = new YourCustomUserStorage();
$server->addStorage($userStorage, 'user_credentials');
You'll also need to pass this storage to any Grant type you're adding to the server, in your case it looks like this:
$server->addGrantType(new OAuth2\GrantType\UserCredentials($userStorage));