/**
* Implements a generic OAuth service provider authentication
*
* @param callable $callback A callable to call when OAuth authentication
* starts
* @param string $oauth OAuth version to be used for authentication
*
* @return null|User Returns a Grav user instance on success.
*/
protected function genericOAuthProvider($callback, $oauth = 'oauth2')
{
/** @var Session */
$session = $this->grav['session'];
switch ($oauth) {
case 'oauth1':
if (empty($_GET['oauth_token']) && empty($_GET['oauth_verifier'])) {
// Extra request needed for OAuth1 to request a request token :-)
$token = $this->service->requestRequestToken();
// Create a state token to prevent request forgery.
// Store it in the session for later validation.
$redirect = $this->service->getAuthorizationUri(['oauth_token' => $token->getRequestToken()]);
$this->setRedirect($redirect);
// Update OAuth session
$session->oauth = $this->action;
} else {
$token = $this->storage->retrieveAccessToken($session->oauth);
// This was a callback request from OAuth1 service, get the token
if (isset($_GET['_url'])) {
parse_str(parse_url($_GET['_url'])['query']);
$this->service->requestAccessToken($oauth_token, $_GET['oauth_verifier'], $token->getRequestTokenSecret());
} else {
$this->service->requestAccessToken($_GET['oauth_token'], $_GET['oauth_verifier'], $token->getRequestTokenSecret());
}
return $callback();
}
break;
case 'oauth2':
default:
if (empty($_GET['code'])) {
// Create a state token to prevent request forgery (CSRF).
$state = sha1($this->getRandomBytes(1024, false));
$redirect = $this->service->getAuthorizationUri(['state' => $state]);
$this->setRedirect($redirect);
// Update OAuth session
$session->oauth = $this->action;
// Store CSRF in the session for later validation.
$this->storage->storeAuthorizationState($this->action, $state);
} else {
// Retrieve the CSRF state parameter
$state = isset($_GET['state']) ? $_GET['state'] : null;
// This was a callback request from the OAuth2 service, get the token
$this->service->requestAccessToken($_GET['code'], $state);
return $callback();
}
break;
}
return;
}
