Guardian provides an adapter between an authentication backend and your PSR-15 middleware stack
- Compatible to the PSR-15 middleware interface
- Adaptable to your authentication backend with a simple interface
<?php
// create a new authentication backend which implements the AuthenticationInterface
$authenticationBackend = new AuthenticationBackend();
// using e.g. mindplay-dk/middleman as a dispatcher for the middleware stack
$response = (new Dispatcher(
[
// inject Guardian with the authentication backend instance
new Guardian($authenticationBackend),
// ... more middlwares e.g. a router
new Router()
]
))->dispatch($request);The focus of Guardian is on the adaptation of an authentication backend with a PSR-15 middleware stack.
This means that Guardian itself is not capable of providing authentication e.g. Basic access authentication. But Guardian ships with a simple interface that can be implemented by the authentication backend. The interface consists of two methods.
<?php
interface AuthenticationInterface
{
/**
* @param ServerRequestInterface $request
* @return bool
*/
public function authenticate(ServerRequestInterface $request);
/**
* @return ResponseInterface
*/
public function getAuthenticationFailedResponse();
}The authenticate method receives the current request as a parameter and must return a boolean (which stands for access approved respectively access denied) .
The getAuthenticationFailedResponse method must return a ResponseInterface instance. It's called by Guardian in case of access denied to return a ResponseInterface instance to the middleware pipeline. The fact that the authentication backend is in charge to provide a proper ResponseInterface instance is due to the need of custom properties.
E.g. an authentication backend, which supports the Basic access authentication, "should return a response whose header contains a HTTP 401 Unauthorized status and a WWW-Authenticate field. The WWW-Authenticate field for basic authentication (used most often) is constructed as following: WWW-Authenticate: Basic realm="User Visible Realm"" [WIKI]