Symfony 2 – Create role- and class-based ACLs with your roles coming from the ORM

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

<?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.

<?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.

<?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 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, 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.

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