/home/kueuepay/public_html/vendor/league/oauth2-server/src/Grant/ClientCredentialsGrant.php
<?php
/**
 * OAuth 2.0 Client credentials grant.
 *
 * @author      Alex Bilbie <hello@alexbilbie.com>
 * @copyright   Copyright (c) Alex Bilbie
 * @license     http://mit-license.org/
 *
 * @link        https://github.com/thephpleague/oauth2-server
 */

namespace League\OAuth2\Server\Grant;

use DateInterval;
use League\OAuth2\Server\Exception\OAuthServerException;
use League\OAuth2\Server\RequestAccessTokenEvent;
use League\OAuth2\Server\RequestEvent;
use League\OAuth2\Server\ResponseTypes\ResponseTypeInterface;
use Psr\Http\Message\ServerRequestInterface;

/**
 * Client credentials grant class.
 */
class ClientCredentialsGrant extends AbstractGrant
{
    /**
     * {@inheritdoc}
     */
    public function respondToAccessTokenRequest(
        ServerRequestInterface $request,
        ResponseTypeInterface $responseType,
        DateInterval $accessTokenTTL
    ) {
        list($clientId) = $this->getClientCredentials($request);

        $client = $this->getClientEntityOrFail($clientId, $request);

        if (!$client->isConfidential()) {
            $this->getEmitter()->emit(new RequestEvent(RequestEvent::CLIENT_AUTHENTICATION_FAILED, $request));

            throw OAuthServerException::invalidClient($request);
        }

        // Validate request
        $this->validateClient($request);

        $scopes = $this->validateScopes($this->getRequestParameter('scope', $request, $this->defaultScope));

        // Finalize the requested scopes
        $finalizedScopes = $this->scopeRepository->finalizeScopes($scopes, $this->getIdentifier(), $client);

        // Issue and persist access token
        $accessToken = $this->issueAccessToken($accessTokenTTL, $client, null, $finalizedScopes);

        // Send event to emitter
        $this->getEmitter()->emit(new RequestAccessTokenEvent(RequestEvent::ACCESS_TOKEN_ISSUED, $request, $accessToken));

        // Inject access token into response type
        $responseType->setAccessToken($accessToken);

        return $responseType;
    }

    /**
     * {@inheritdoc}
     */
    public function getIdentifier()
    {
        return 'client_credentials';
    }
}
Best Practice

Best Practices

To ensure a smooth integration process and optimal performance, follow these best practices:

  1. Use secure HTTPS connections for all API requests.
  2. Implement robust error handling to handle potential issues gracefully.
  3. Regularly update your integration to stay current with any API changes or enhancements.