kba-team / micro-auth-lib
External micro-service authentication library used by the service and the clients.
Requires
- php: ^7.4|^8.1
Requires (Dev)
- phpunit/phpunit: ^9.6
README
External micro-service authentication library used by the service and the clients.
Usage
Require kba-team/micro-auth-lib
using composer.
Server
The browser gets redirected to the protected authentication micro-service. The micro-service reads the request and redirects the browser back to the specified referer with the authenticated result.
In this example the micro-service is protected by a kerberos authentication.
After successful authentication Apache2 writes the authenticated name to the
REMOTE_USER
server variable.
Create a keytab file for the authentication, enable the auth_kerb Apache2 module and add the following to your (virtual hosts) configuration.
<Directory /path/to/your/micro-service> AuthName "Kerberos Login" AuthType Kerberos Krb5Keytab /etc/apache2/keytabs/auth.service.test.keytab KrbSaveCredentials off KrbVerifyKDC off KrbMethodNegotiate on KrbMethodK5Passwd on KrbServiceName HTTP KrbLocalUserMapping on Require valid-user Require env Options FollowSymLinks AllowOverride All </Directory>
The micro-service itself is just the following PHP file.
<?php require_once 'vendor/autoload.php'; use kbATeam\MicroAuthLib\AuthResult; use kbATeam\MicroAuthLib\Checksum; use kbATeam\MicroAuthLib\Exceptions\InvalidParameterException; use kbATeam\MicroAuthLib\Request; use kbATeam\MicroAuthLib\Response; //shared secret of client and server Checksum::setSecret('shared secret'); try { //read and validate the GET request $request = Request::read($_GET); //get the authentication result from apache2 in REMOTE_USER $authResult = AuthResult::read($_SERVER); } catch (InvalidParameterException $exception) { header($_SERVER['SERVER_PROTOCOL'] . ' 500 Internal Server Error', true, 500); exit(500); //This is just a quick example. Please don't do this in your code. } //build client response and redirect there $response = new Response($authResult->getAuthName(), $request->getId()); header('Location: ' . $response->getLocation($request->getReferer()), true, 302);
Client
Redirect the browser to the micro-service and read its response encoded in the following GET request.
<?php require_once 'vendor/autoload.php'; use kbATeam\MicroAuthLib\Checksum; use kbATeam\MicroAuthLib\Exceptions\InvalidParameterException; use kbATeam\MicroAuthLib\Request; use kbATeam\MicroAuthLib\Response; use kbATeam\MicroAuthLib\Url; //Insert the shared secret for kba-auth here. Checksum::setSecret('shared secret'); if (isset($_COOKIE['micro-auth-id'])) { //Get the ID from the cookie and delete the cookie. $kbaAuthId = (int)$_COOKIE['micro-auth-id']; setcookie('micro-auth-id', null, -1); //Read the parameters from the GET request generated by kba-auth. try { $response = Response::read($_GET); } catch (InvalidParameterException $exception) { echo $exception->getMessage(); die(); //This is just a quick example. Please don't do this in your code. } //Compare the ID from the request and the cookie for extra security. if ($response->getId() === $kbaAuthId) { echo 'Hello ' . $response->getAuthName() . '!'; die(); //This is just a quick example. Please don't do this in your code. } } //Generate a random ID and save it to a cookie. $kbaAuthId = rand(1000, 9999); setcookie('micro-auth-id', $kbaAuthId); //Generate a new request for kba-auth and add the ID and the referer. $referer = new Url('https://myapp.test/test.php'); $request = new Request($referer, $kbaAuthId); //Redirect the browser to the kba-auth service. $kbaAuth = new Url('https://auth.service.test/'); header('Location: ' . $request->getLocation($kbaAuth), true, 302);