Symfony 2 – Create role- and class-based ACLs with your roles coming from the ORM
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:date: 2012-09-16T18:39:25Z
:category: blog
:tags: php,symfony
:url: blog/2012/9/16/symfony-2-create-role-and-class-based-acls-with-your-roles-coming-from-the-orm.html
:save_as: blog/2012/9/16/symfony-2-create-role-and-class-based-acls-with-your-roles-coming-from-the-orm.html
:status: published
:author: Gergely Polonkai

During the last weeks I had some serious issues with one of my private Symfony 2 projects.  One of
my goals was to create a dynamic security system, e.g my administrators wanted to create roles,
and grant these roles access to different object types (classes) and/or objects.

So I have created a ``User`` entity, which implements ``UserInterface`` and
``AdvancedUserInterface``, the latter for the possibility to enable/disable accounts and such.  It
had a ``$roles`` property, which was a ``ManyToMany`` relation to the ``Role`` entity, which
implemented ``RoleInterface``.  Also I have created my own role hierarchy service that implements
``RoleHierarchyInterface``.

So far so good, first tests.  It soon turned out that if ``User::getRoles()`` returns a
``DoctrineCollection`` as it does by default, then the standard

.. code-block:: php

   <?php
   $this->get('security.context')->isGranted('ROLE_ADMIN');

doesn’t work.  I know, it should not be hard coded, as my roles and permission tables are dynamic,
I have just tested.  So I fixed my ``User`` entity so ``getRoles()`` returns an array of ``Role``
objects instead of the ``DoctrineCollection``.  Also I implemented a ``getRolesCollection()``
method to return the original collection, but I think it will never be used.

After that, I had to implement some more features so I put this task away.  Then, I tried to
create my first ACL.

.. code-block:: php

   <?php
   $securityIdentity = new RoleSecurityIdentity('ROLE_ADMIN');
   $objectIdentity = new ObjectIdentity('newsClass', 'Acme\\DemoBundle\\Entity\\News');
   $acl = $aclProvider->createAcl($objectIdentity);
   $acl->insertClassAce($securityIdentity, MaskBuilder::MASK_OWNER);
   $aclProvider->updateAcl($acl);

I was about to check if the user who is logged in has an ``OWNER`` permission on the ``User``
class.

.. code-block:: php

   <?php
   $this->objectIdentity = new ObjectIdentity(self::OBJECT_ID, self::OBJECT_FQCN);
   if ($this->securityContext->isGranted('OWNER', $this->objectIdentity) === false) {
       throw new AccessDeniedException('You don’t have the required permissions!');
   }

The ACL was defined based on a role, so everyone who had the ``ROLE_ADMIN`` role should gain
access to the user listing page.  But they didn’t.  It took several weeks to find the cause, I
have put it on `stackoverflow
<http://stackoverflow.com/questions/12057795/symfony-2-1-this-getsecurity-context-isgrantedrole-admin-returns-fa>`_
and the Symfony Google Group, but no usable answers.

Then I went off for debugging.  Setting up NetBeans for xdebug-based PHP debugging was real fun
under Fedora, but that’s another story.  After a while I have found that Symfony’s basic access
decision manager checks for ``$role->getRole()`` only if ``$role`` is an instance of
``Symfony\Component\Security\Core\Role\Role``, instead of checking if the object implements
``Symfony\Component\Security\Core\Role\RoleInterface``.  So I’ve checked if the bug is already
reported.  It turned out that it was, and my solution was available in a specific commit about a
year ago, but as `Johannes Schmitt commented, it would introduce a security issue
<https://github.com/symfony/symfony/commit/af70ac8d777873c49347ac828a817a400006cbea>`_, so it was
reverted.  Unfortunately neither Johannes Schmitt, nor Fabien Potencier (nor anyone else) could (or
wanted) to tell about this issue.  So the final (and somewhat hack-like) solution was to extend
``Symfony\Component\Security\Core\Role\Role``.  And boom!  It worked.
