Masquerade grant type

MasqueradeGrant.php

<?php


namespace MyApp\OAuth2\GrantType;

use OAuth2\RequestInterface;
use OAuth2\ResponseInterface;
use OAuth2\Storage\ClientCredentialsInterface;
use OAuth2\Storage\AccessTokenInterface;

class MasqueradeGrant implements GrantTypeInterface {

    private $tokenStorage;

    public function __construct(AccessTokenInterface $tokenStorage) {
        $this->tokenStorage = $tokenStorage;
    }


    public function getQuerystringIdentifier() {
        return 'masquerade';
    }

    public function validateRequest(RequestInterface $request, ResponseInterface $response) {

        if(!$this->clientAssertion->validateRequest($request, $response)) {
            return false;
        }

        if (!$request->request("token")) {
            $response->setError(400, 'invalid_request', 'An access token is required');
            return null;
        }

        $access_token = $this->tokenStorage->getAccessToken($request->request('token'));

        if(!isset($access_token['expires']) || $access_token['expires'] < time()){
            $response->setError(400, 'invalid_request', 'The access token has expired');
            return null;
        }

        if(!isset($access_token['scope']) || !in_array('masquerade', explode(' ',  $access_token['scope']))){
            $response->setError(400, 'invalid_request', 'The access token does not have sufficient privilege');
            return null;
        }

        $this->userInfo = User::loadById($request->request('user_id', $access_token['user_id']));

        return true;
    }
    
    public function getClientId()
    {
        return null;
    }

    public function getUserId()
    {
        return $this->userInfo['user_id'];
    }

    public function getScope()
    {
        return isset($this->userInfo['scope']) ? $this->userInfo['scope'] : null;
    }

    public function createAccessToken(AccessTokenInterface $accessToken, $client_id, $user_id, $scope)
    {
        return $accessToken->createAccessToken($client_id, $user_id, $scope);
    }

}

server.php

<?php

use MyApp\OAuth2\GrantType\MasqueradeGrant;

$storage = new OAuth2\Server\Pdo();
$server = new OAuth2\Server($storage);

$server->addGrantType(new MasqueradeGrant($app['sdk'], $storage, $app['oauth_jwt_token_storage']), 'console');

I've removed a fair chunk from the MasqueradeGrant.php file, so it probably won't work if you try to run it, but it should give you an idea.