Creating fast, dynamic ACLs in Zend Framework
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The document discusses using the Zend Framework's Zend_Acl component to implement access control lists (ACLs) for authorization in a dynamic web application. It describes how Zend_Acl works and some of its limitations as complexity increases. It then presents an alternative approach that uses a database backend with caching to define ACL rules externally for improved maintenance, and integrates authorization checks directly into the MVC request rather than at the resource level.
Creating fast, dynamic ACLs in Zend Framework
- 1. Creating fast, dynamic ACLs in Zend Framework Wim Godden Cu.be Solutions
- 2. Who am I ? Wim Godden (@wimgtr)
- 3. Owner of Cu.be Solutions (http://cu.be)
- 4. PHP developer since 1997
- 7. Zend Framework Certified Engineer
- 9. Talking about... Authentication -> Zend_Auth Auditing -> Zend_Log Authorization -> Zend_Acl
- 10. Authorization Wikipedia : "the function of specifying access rights to resources"
- 11. What's a resource ? Object (Article, Invoice, Document, …)
- 12. Webpage
- 13. Database / table / row
- 14. ...
- 15. Standard ACL Access to resources is defined in privileges
- 16. Privileges are grouped together in roles
- 17. 2 types of roles : Anonymous / Unknown
- 19. Zend_Acl : the good Flexible
- 20. Uses standard role / resource principles Recognizable -> easy to get started No link to specific backend
- 21. Allow + deny
- 22. Proven, tested
- 23. Zend_Acl : the bad & ugly Complexity of rules rises quickly
- 25. All rules are in-code
- 26. -> maintainability becomes an issue
- 27. Evolution of a portal $acl = new Zend_Acl(); $acl->addRole( new Zend_Acl_Role( 'guest' )); $acl->addRole( new Zend_Acl_Role( 'member' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'admin' ), 'member' ); $acl->addResource( new Zend_Acl_Resource( 'cms' )); $acl->addResource( new Zend_Acl_Resource( 'report' )); $acl->allow( 'guest' , 'cms' , 'view' ); $acl->allow( 'admin' , 'cms' , 'edit' ); $acl->deny( 'guest' , 'report' ); $acl->allow( 'member' , 'report' );
- 28. Evolution of a portal $acl = new Zend_Acl(); $acl->addRole( new Zend_Acl_Role( 'guest' )); $acl->addRole( new Zend_Acl_Role( 'departmentA' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentB' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'admin' ), 'member' ); $acl->addResource( new Zend_Acl_Resource( 'cms' )); $acl->addResource( new Zend_Acl_Resource( 'report' )); $acl->allow( 'guest' , 'cms' , 'view' ); $acl->allow( 'admin' , 'cms' , 'edit' ); $acl->deny( 'guest' , 'report' ); $acl->allow( 'departmentA' , 'report' );
- 29. Evolution of a portal $acl = new Zend_Acl(); $acl->addRole( new Zend_Acl_Role( 'guest' )); $acl->addRole( new Zend_Acl_Role( 'departmentA' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentB' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentC_senior_staff' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentC_marketing' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'admin' ), 'member' ); $acl->addResource( new Zend_Acl_Resource( 'cms' )); $acl->addResource( new Zend_Acl_Resource( 'report' )); $acl->addResource( new Zend_Acl_Resource( 'newsletter' )); $acl->addResource( new Zend_Acl_Resource( 'photo' )); $acl->addResource( new Zend_Acl_Resource( 'faq' )); $acl->allow( 'guest' , 'cms' , 'view' ); $acl->allow( 'admin' , 'cms' , 'edit' ); $acl->deny( 'guest' , 'report' ); $acl->allow( 'departmentA' , 'report' ); $acl->deny('departmentC_senior_staff', 'newsletter'); $acl->allow('departmentC_marketing', 'newsletter'); $acl->allow('member', 'photo', 'view'); $acl->allow('departmentC_marketing', 'photo', 'upload'); $acl->allow('admin', 'photo', 'delete'); $acl->allow('guest', 'faq', 'view'); $acl->allow('member', 'faq', 'comment'); $acl->allow('departmentA', 'faq', 'edit'); $acl->allow('departmentC_senior_staff', 'faq', 'edit'); $acl->allow('admin', 'faq', 'edit');
- 30. Evolution of a portal $acl = new Zend_Acl(); $acl->addRole( new Zend_Acl_Role( 'guest' )); $acl->addRole( new Zend_Acl_Role( 'departmentA' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentB' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentC_senior_staff' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentC_marketing' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'cook' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'admin' ), 'member' ); $acl->addResource( new Zend_Acl_Resource( 'cms' )); $acl->addResource( new Zend_Acl_Resource( 'report' )); $acl->addResource( new Zend_Acl_Resource( 'newsletter' )); $acl->addResource( new Zend_Acl_Resource( 'photo' )); $acl->addResource( new Zend_Acl_Resource( 'faq' )); $acl->addResource( new Zend_Acl_Resource( 'invoicing' )); $acl->addResource( new Zend_Acl_Resource( 'stats' )); $acl->addResource( new Zend_Acl_Resource( 'lunchmenu' )); $acl->allow( 'guest' , 'cms' , 'view' ); $acl->allow( 'admin' , 'cms' , 'edit' ); $acl->deny( 'guest' , 'report' ); $acl->allow( 'departmentA' , 'report' ); $acl->deny('departmentC_senior_staff', 'newsletter'); $acl->allow('departmentC_marketing', 'newsletter'); $acl->allow('member', 'photo', 'view'); $acl->allow('departmentC_marketing', 'photo', 'upload'); $acl->allow('admin', 'photo', 'delete'); $acl->allow('guest', 'faq', 'view'); $acl->allow('member', 'faq', 'comment'); $acl->allow('departmentA', 'faq', 'edit'); $acl->allow('departmentC_senior_staff', 'faq', 'edit'); $acl->allow('admin', 'faq', 'edit'); $acl->allow('admin', 'photo', 'delete'); $acl->allow('guest', 'faq', 'view'); $acl->allow('member', 'faq', 'comment'); $acl->allow('departmentA', 'faq', 'edit'); $acl->allow('departmentC_senior_staff', 'faq', 'edit'); $acl->allow('admin', 'faq', 'edit'); $acl->allow('cook', 'lunchmenu', 'edit'); $acl->allow('member', 'lunchmenu', 'view'); $acl->allow('accounting', 'invoicing', 'edit'); $acl->allow('admin', 'invoicing', 'edit'); $acl->allow('departmentC_senior_staff', 'invoicing', 'report');
- 31. Evolution of a portal $acl = new Zend_Acl(); $acl->addRole( new Zend_Acl_Role( 'guest' )); $acl->addRole( new Zend_Acl_Role( 'departmentA' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentB' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentC_senior_staff' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'departmentC_marketing' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'cook' ), 'guest' ); $acl->addRole( new Zend_Acl_Role( 'admin' ), 'member' ); $acl->addResource( new Zend_Acl_Resource( 'cms' )); $acl->addResource( new Zend_Acl_Resource( 'report' )); $acl->addResource( new Zend_Acl_Resource( 'newsletter' )); $acl->addResource( new Zend_Acl_Resource( 'photo' )); $acl->addResource( new Zend_Acl_Resource( 'faq' )); $acl->addResource( new Zend_Acl_Resource( 'invoicing' )); $acl->addResource( new Zend_Acl_Resource( 'stats' )); $acl->addResource( new Zend_Acl_Resource( 'lunchmenu' )); $acl->allow( 'guest' , 'cms' , 'view' ); $acl->allow( 'admin' , 'cms' , 'edit' ); $acl->deny( 'guest' , 'report' ); $acl->allow( 'departmentA' , 'report' ); $acl->deny('departmentC_senior_staff', 'newsletter'); $acl->allow('departmentC_marketing', 'newsletter'); $acl->allow('member', 'photo', 'view'); $acl->allow('departmentC_marketing', 'photo', 'upload'); $acl->allow('admin', 'photo', 'delete'); $acl->allow('guest', 'faq', 'view'); $acl->allow('member', 'faq', 'comment'); $acl->allow('departmentA', 'faq', 'edit'); $acl->allow('departmentC_senior_staff', 'faq', 'edit'); $acl->allow('admin', 'faq', 'edit'); $acl->allow('admin', 'photo', 'delete'); $acl->allow('guest', 'faq', 'view'); $acl->allow('member', 'faq', 'comment'); $acl->allow('departmentA', 'faq', 'edit'); $acl->allow('departmentC_senior_staff', 'faq', 'edit'); $acl->allow('admin', 'faq', 'edit'); $acl->allow('cook', 'lunchmenu', 'edit'); $acl->allow('member', 'lunchmenu', 'view'); $acl->allow('accounting', 'invoicing', 'edit'); $acl->allow('admin', 'invoicing', 'edit'); $acl->allow('departmentC_senior_staff', 'invoicing', 'report');
- 32. Hard to ... maintain all rules
- 33. keep track of the rules
- 34. debug the rules
- 35. Possible solution : database Extend Zend_Acl to database driven design
- 36. Good : no code changes required
- 37. Bad : more load on DB
- 38. A different approach Not THE solution, merely A solution
- 41. ZF Conventional Modular Directory Structure
- 42. Backend interface for easy management with a twist !
- 43. Different resources Zend_ACL : $acl->addResource( new Zend_Acl_Resource( 'cms' )); $acl->allow( 'guest' , 'cms' , 'view' ); $acl->allow( 'admin' , 'cms' , 'edit' ); Access to : Controller : cms
- 44. Action : view / edit Why not integrate with the request itself ?
- 46. Zend_Acl as a controller plugin <?php class My_Plugin_Acl extends Zend_Controller_Plugin_Abstract { private $_acl = null; public function __construct(Zend_Acl $acl ) { $this ->_acl = $acl ; } public function preDispatch(Zend_Controller_Request_Abstract $request ) { $role = (Zend_Auth::getInstance()->hasIdentity()) ? 'user' : 'guest' ; //For this example, we will use the controller as the resource: $resource = $request ->getControllerName(); if (! $this ->_acl->isAllowed( $role , $resource , 'view' )) { //If the user has no access we send him elsewhere by changing the request and resetting the dispatch $request ->setModuleName( 'auth' ) ->setControllerName( 'auth' ) ->setActionName( 'login' ) ->setDispatched(false); return false; } } }
- 47. Initializing the ACL Let's have a look
- 48. Zend_Acl manual rules <?php class My_Acl extends Zend_Acl { public function __construct() { //Add a new role called "guest" $this ->addRole( new Zend_Acl_Role( 'guest' )); //Add a role called user, which inherits from guest $this ->addRole( new Zend_Acl_Role( 'user' ), 'guest' ); //Add a resource called page $this ->add( new Zend_Acl_Resource( 'page' )); //Add a resource called news, which inherits page $this ->add( new Zend_Acl_Resource( 'news' ), 'page' ); //Finally, we want to allow guests to view pages $this ->allow( 'guest' , 'page' , 'view' ); //and users can comment news $this ->allow( 'user' , 'news' , 'comment' ); } }
- 49. Our ACL id role_id module controller action 1 2 newsletter send index 2 1 cms article edit 3 3 % % % id name email pw 1 Chris [email_address] ******* 2 Jake [email_address] ******* 3 Jeniffer [email_address] ******* id name 1 webmaster 2 marketeer 3 admin user_id role_id 1 2 2 3 3 1
- 50. Application_Acl class Application_Acl { public function isAllowed($user = null , $request = null ) { if (is_null($user) === false && $user !== false && $user instanceof User) { $userId = $user-> id ; } else { $userId = 0; } $db = Zend_Db_Table:: getDefaultAdapter (); $stmt = $db->query( ' select module_name, controller_name, action_name from privilege join role on role.id = privilege.role_id join userRole on userRole.role_id = role.role_id where userRole.user_id = ? and ( module_name = "%" or ( module_name = ? and ( controller_name = "%" or ( controller_name = ? and ( action_name = "%" or action_name = ? ) ) ) ) ) ' , array ( $userId, $request->getModuleName(), $request->getControllerName(), $request->getActionName() ) ); $stmt->execute(); $row = $stmt->fetch(); // Returns a row or false if ($row !== false ) { return true ; } else { return false ; } } }
- 51. To cache or not to cache - Option 1 (no cache) 1 query per ACL request
- 52. = 1 query per pageview / ajax request
- 53. 99.99% will be identical
- 54. -> "Just rely on MySQL query cache !"
- 55. FAIL !
- 56. Even for cached queries, MySQL connections use memory, I/O, CPU, ...
- 57. Caching - Option 2 (cache the main query) 1 DB query per user for each unique ACL request
- 58. User with 20 privileges -> 20 possible requests
- 59. All subsequent pageviews : 1 cache request
- 60. What's in the cache ? Entry Data acl_user_3_%_%_% 1 acl_user_1_cms_article_edit 1 acl_user_1_admin_destroy_planet 0 Problem : what if we add a privilege to a role ? -> All cached entries for all users should be refreshed (ouch !)
- 61. Caching - Option 3 - denormalize in cache
- 62. What's in the cache ? Entry Data acl_user_3 3, 1, 4 acl_user_1 3, 1, 2 acl_role_1 a:3:{i:0;s:45:"a:2:{i:0;s:5:"%_%_%";}";i:1;i:1308106740;i:2;s:6:"604800";} User's roles Privileges listed in a role
- 63. Caching - Option 3 - denormalize in cache 1 DB query per user at login (retrieve user's roles)
- 64. User with 20 privileges -> just 1 DB query
- 65. Per pageview : 1 cache query + 1 cache query per role
- 66. Good : Less queries on DB
- 67. Less data in the cache (only roles, not full privileges of each user)
- 68. Add a privilege to a role -> update the role only Bad : More queries on cache Choice : depends on where your highest load is (but memory is cheap and Memcache is fast !)
- 69. Caching - let's have a look
- 70. Managing the roles / privileges Zend_Acl : manual typ(o)ing
- 72. easy management -> Reflection
- 73. Reflection ? Used to inspect objects during run-time
- 74. Available since PHP 5.0
- 75. Can be applied to : Classes
- 76. Objects
- 77. Methods
- 78. Functions
- 79. Properties
- 80. Extensions
- 81. Reflection - example <?php class Test { static public function testMe ($reason) { echo 'I have a reason : ' . $reason; } } $reflector = new ReflectionClass( 'Test' ); echo 'Class name : ' . $reflector->getName() . "\n" ; echo "Methods : \n" ; var_dump($reflector->getMethods()); Outputs : Class name : Test Methods : array(1) { [0]=> &object(ReflectionMethod)#2 (2) { ["name"]=> string(6) "testMe" ["class"]=> string(4) "Test" } }
- 82. Backend interface with reflection
- 83. Version 1 -> 2 ZF2 compatible Maybe : adding a multiGet() for the roles -> fewer cache queries Resources isAllowed() gets a new parameter
- 84. can be combined with module/controller/action Negative privileges and negative roles (!)
- 85. Hide controllers and actions from the interface (docblock)
- 87. Apply roles to usergroup
- 88. Setting it up library/Application/Acl.php -> main ACL class
- 92. LoginController.php -> Login screen (usually placed somewhere else) modules/um/views/scripts/ index
- 93. role Few lines in application.ini
- 94. Where to get it Site : http://www.opensource.be/zfacl/ (Oct 25)
- 95. Code : Github (see site)
- 96. Questions ?
- 97. Questions ?
- 98. Contact Web http://techblog.wimgodden.be
- 100. Twitter @wimgtr
- 102. Please... Rate my talk : http://joind.in/4009
- 103. Thanks !