Zend AMF Authentication & Authorization

dkozar evolved a working method to Authenticate and Authorize a Flex based app datas service call using Zend AMF, he writes;

I’ve been struggling with it, and figured it all out – so, perhaps it could help others.

The authentication is called on the server only if credentials supplied from the client (via the remote procedure call headers). This snippet illustrates the setup of custom auth (these are the last 6 lines of gateway.php script):

// Handle request
$auth = new My_Amf_Auth(); // authentication
$server->setAuth($auth);
$acl = new Zend_Acl(); // authorization
$server->setAcl($acl);
echo $server->handle();

Now, your custom auth should extend Zend_Amf_Auth_Abstract. Since I want to authenticate users from a database, I bring the Zend_Auth_Adapter_DbTable to play. But since I cannot extend both Zend_Amf_Auth_Abstract and Zend_Auth_Adapter_DbTable, I use a composition:

< ?php require_once ('Zend/Amf/Auth/Abstract.php');/** * AMF auth class by Danko Kozar, dankokozar.com * @author dkozar * */ class My_Amf_Auth extends Zend_Amf_Auth_Abstract { function __construct() { } public function authenticate() { $adapter = My_Db_Adapter::getInstance(); $adapter->setIdentity($this->_username);
$adapter->setCredential($this->_password);

// the adapter call
// you can wrap it into try.. catch and process DB connection errors
$result = Zend_Auth::getInstance()->authenticate($adapter);

return $result;
}
}

Here’s the adapter class:

< ?php /** * DB table adapter auth class for AMF by Danko Kozar, dankokozar.com * @author dkozar * Singleton */ class My_Db_Adapter extends Zend_Auth_Adapter_DbTable { protected static $_instance = null; /** * private! * @param My_Db_Adapter $adapter */ public function __construct(Zend_Db_Adapter_Abstract $adapter = null) { if (!$adapter) $adapter = new Zend_Db_Adapter_Mysqli( array( 'dbname' => 'test',
'username' => 'root',
'password' => '')
);

parent::__construct($adapter);

$this
->setTableName('users')
->setIdentityColumn('username')
->setCredentialColumn('password')
;

// just for testing
// $this
// ->setIdentity('username')
// ->setCredential('password')
// ;
}

/**
* @return My_Db_Adapter
*/
public static function getInstance()
{
if (null === self::$_instance) {
self::$_instance = new self();
}
return self::$_instance;
}

public function authenticate() {

$_authResult = parent::authenticate();

// NOTE: The point is that $result->_identity is an OBJECT (of type stdClass), NOT string
// with Zend_Auth_Adapter_DbTable it is internally accomplished by calling its getResultRowObject() method
// It constructs the stdClass with properties named after table attributes

// $user = new stdClass();
// $user->role = "administrator";
// $user->username = $_authResult->getIdentity();

$identity = $this->getResultRowObject();

$result = new Zend_Auth_Result($_authResult->getCode(), $identity);

return $result;
}
}

MyService.php class. Here it is:


< ?php /** * PHP service class with authorization * by Danko Kozar, dankokozar.com * @author dkozar * */ class MyService { /** * from zend docs: * If the ACL object is set, and the class being called defines initAcl() method, * this method will be called with the ACL object as an argument. * This method can create additional ACL rules and return TRUE, * or return FALSE if no access control is required for this class. * * @param Zend_Acl $acl * @return boolean */ public function initAcl($acl) { $acl->addRole(new Zend_Acl_Role("administrator"));
$acl->addRole(new Zend_Acl_Role("user"));

//acl "allow" method takes 3 parameters (role, resource - class name, privileges - it's function name in this class)

// administrator
$acl->allow('administrator', 'MyService', 'helloWorld');
$acl->allow('administrator', 'MyService', 'getData');

// user
$acl->allow('user', 'MyService', 'helloWorld');
$acl->deny('user', 'MyService', 'getData');

//returning true to signal that we want to check privileges before accessing methods of this class
//in my tests if we don't return anything it will treat it like we will return false so better return true or false
//your intentions will be clear
return true;
}

/**
* Hello world method
*/
public function helloWorld(){
return "Hello world from MyService service";
}

/**
*
* Returns data
* @return [int]
*/
function getData()
{
$arr = array(1, 2, 3);
return $arr;
}
}
?>

Note that the authorization is being built dynamically inside the initAcl method.

On the Flex side I have an auto-generated class (MyService) which extends another auto-generated class (_Super_MyService).

The point is that the outer one is auto-generated only once (initially), and you can modify it, without worrying to be overwritten on service regeneration.

There’s a protected property _serviceControl (which is of type RemoteObject) which could be tweaked if needed.

I’m tweaking it by of setting the endpoint (with string read from a client side config in preInitializeService() method). Plus, I’m adding 2 more methods, which expose setCredentials and setRemoteCredentials methods of _serviceControl, so I can acces it from my code.


package services.myservice
{
public class MyService extends _Super_MyService
{
/**
* Override super.init() to provide any initialization customization if needed.
*/
protected override function preInitializeService():void
{
super.preInitializeService();

// Initialization customization goes here
_serviceControl.endpoint = "http://localhost/myapp/gateway.php";
}

public function setCredentials(username:String, password:String, charset:String=null):void
{
_serviceControl.setCredentials(username, password, charset);
}

public function setRemoteCredentials(username:String, password:String, charset:String=null):void
{
_serviceControl.setRemoteCredentials(username, password, charset);
}
}
}


So, before calling MyService methods, I’m setting the credentials with setCredentials() method and this runs the authentication on the PHP side:


private var service:MyService;
....
service = new MyService(); // ServiceLocator.getInstance().getHTTPService("presetLoader");
service.setCredentials("user1", "pass1");
var token:AsyncToken = service.getData();

The authentication via Zend_Amf_Server is, by the way, OPTIONAL! Meaning, with no credentials supplied, Zend_Amf_Server will NOT RUN IT. Thus you should rely on Zend_Acl (e.g. roles) to so your permissions and security!

Finally, here’s the MySQL DB table I’ve been using for authentication:

--
-- Table structure for table `users`
--
CREATE TABLE IF NOT EXISTS `users` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(50) NOT NULL,
`password` varchar(32) DEFAULT NULL,
`role` varchar(45) DEFAULT NULL,
`firstname` varchar(50) DEFAULT NULL,
`lastname` varchar(50) DEFAULT NULL,
`email` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `username` (`username`),
UNIQUE KEY `id_UNIQUE` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=2 ;

--
-- Dumping data for table `users`
--
INSERT INTO `users` (`id`, `username`, `password`, `role`, `firstname`, `lastname`, `email`) VALUES
(1, 'user1', 'pass1', 'administrator', 'Danko', 'Kozar', NULL);

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Cheers!
Danko

Adobe Forums

Authentication using Zend_Amf

Kevin Schroeder writes; I forget why, but a few days ago I started doing some digging around with authentication in Zend_Amf_Server. I had figured that I would add an adapter to the Zend_Amf_Server::setAuth() method and that would be it.

But I was wrong.

AMF allows for multiple request bodies to be sent at the same time. Of those there are several “special” types of commands. One of those commands is logging in. What this means is that you don’t need a method that logs someone in for you. Zend_Amf_Server handles authentication separately from your service classes.

Authentication for Zend_Amf_Server will generally use a combination of Zend_Auth and Zend_Acl components. Zend_Auth is used to provide the credential verification while Zend_Acl is used to validate that the current user user can access the requested service method. It is actually a relatively trivial task to restrict access to non-logged in users using the method that I will describe here.

The first step in the process is to create an authentication adapter. It really doesn’t matter what you’re using. What matters is that the adapter returns an identity object with a property called “role”. The built in ACL handle expects this to be part of the identity object.


class Auth extends Zend_Amf_Auth_Abstract
{
const LOGGEDIN_ROLE = 'loggedin';

public function authenticate()
{
$identity = new stdClass();
$result = Zend_Auth_Result::FAILURE;

// Do a proper login, y'all
if ($this->_username == 'test' && $this->_password == 'test') {
$identity->role = self::LOGGEDIN_ROLE;
$result = Zend_Auth_Result::SUCCESS;
} else {
$identity->role = Zend_Amf_Constants::GUEST_ROLE;
}

return new Zend_Auth_Result($result, $identity);
}
}

The Auth class extends Zend_Amf_Auth_Abstract because Flex seems to require username and passwords as being the only mechanism for passing credentials. The abstract class defines a method that hooks in with the special commands and passes the special credentials to the special adapter. Clearly your authentication mechanism should be better than the one that I put in here, but you’ll get the idea. The most important part is adding the role property to the identity object and passing it to the Zend_Auth_Result object.

Then in your gateway you need to add this adapter as well as create an simple ACL.


$server = new Zend_Amf_Server();
$server->addDirectory(realpath(__DIR__.'/../services'));

$acl = new Zend_Acl();
$acl->addRole(Auth::LOGGEDIN_ROLE);
$acl->allow(Auth::LOGGEDIN_ROLE);
$server->setAcl($acl);

$auth = new Auth();
$server->setAuth($auth);

echo $server->handle();

This adds the new Auth role to the ACL and says that it has access to everything. Since there is no place where I allow guest access (denoted by Zend_Amf_Constants::GUEST_ROLE in the adapter) guest requests will be denied.

With just this little bit of code you now have a mechanism that will provide restricted access to all of your service objects.

via Kevin Schroeder’s blog – Zend Technologies.

File uploads with Adobe Flex and Zend AMF

Leonardo França writes; Zend AMF is an implementation done in PHP to work with the communication protocol binary AMF (Action Message Format) and is part of ZendFramework. I had to implement a system to upload files that were a little different than what is typically used in Flash, with this feature had to be integrated into the Zend AMF.
Researching a little on the net, found a solution that was simpler than I thought based on that article with a few adjustments.
Begin with our gateway to be used as endpoint in Adobe Flex.

< ?php require_once 'Zend/Amf/Server.php'; require_once 'Zend/Amf/Exception.php'; require_once 'br/com/leonardofranca/vo/FileVO.php'; require_once 'br/com/leonardofranca/UploadZendAMF.php'; $server = new Zend_Amf_Server(); $server->setProduction(false);

$server->setClass('UploadZendAMF');
$server->setClassMap('FileVO',"br.com.leonardofranca.vo.FileVO");

echo($server->handle());
?>

Read more at; File uploads with Adobe Flex and Zend AMF – Workflow: Flash.

10 X Zend Amf Performance enhancements — please test!

Wade Arnold comes with some very good news for us that use Zend_Amf, he writes; Mark Reidenbach from everytruckjob.com has submitted a awesome patch for Zend Amf that creates a huge performance increase. Thanks so much Mark! I have also added a reference check optimization that uses SPL_object_hash to quickly see if an object has been seen before or not. Overall you should see a big performance increase. The test case I used was the James Ward’s census data from my ZendCon talk which consists of random people objects ranging from 1 – 100 duplicates totaling 5k total rows.  Xdebug profiling analyzed by  KCacheGrind showed roughly a 10X increase in performance!

The question is did all of these changes introduce any bugs? I have not been able to find anything and all of the tests pass. However with such a major change I would really appreciate you downloading the attached file and overwriting Zend/Amf/* with it’s contents. Please report any issues in the comments here or better yet on the actual bug ZF-7493 If all goes well we will try and get this into the 1.10 release.

via 10X Zend Amf Performance enhancements — please test! | Wade Arnold.

Object-relational mapping with Doctrine, Flash Builder, and PHP

Richard Bates @ Zend Developer Zone wrote a good article on my favorite ORM Doctrine integration in Zend;

Rich Internet applications built with Adobe Flex and Flash Builder have been steadily gaining a foothold in enterprise development for quite some time. As the platform has grown and evolved, PHP has also made amazing progress toward becoming a mature, powerful object-oriented language with rapid adoption and dozens of frameworks and design pattern implementations. As PHP continues to prosper, developers are able to borrow more and more of the things Java has got right, taking one check after another from the “Java-only” column. One outstanding example of this is object-relational mapping (ORM). A few different PHP ORM implementations are available, and all of them have positive attributes. However, after some experimentation, I’ve found that Doctrine is my favorite.

Read the complete story;

Object-relational mapping with Doctrine, Flash Builder, and PHP.

ZamfBrowser 1.0

When doing AMF projects especially in AIR it’s good to see what gets returned from your Zend_AMF services, here is the solution; ZamfBrowser allows developers to unit test ZendAMF Service classes via an Adobe AIR application. Implementation requires a simple edit to the ZendAMF gateway file that allows ZamfBrowser to introspect your server set up and provide access for all classes and methods registered with the Zend_Amf_Server object. For version 1.0 the ZamfBrowser AIR source code is still closed, but it is intended to go Open Source as soon as the source code documentation is complete and a couple of features are implemented that are still in the pipeline.

Go and get it: http://www.zamfbrowser.org/