* :doc:`/cookbook/security/remember_me`

* :doc:`/cookbook/security/impersonating_user`

* :doc:`/cookbook/security/voters`

* :doc:`/cookbook/security/voters_data_permission`

* :doc:`/cookbook/security/acl`

* :doc:`/cookbook/security/acl_advanced`

* :doc:`/cookbook/security/force_https`

Using ACL's isn't trivial, and for simpler use cases, it may be overkill.

If your permission logic could be described by just writing some code (e.g.

to check if a Blog is owned by the current User), then consider using

:doc:`voters</cookbook/security/voters>`. A voter is passed the object

:doc:`voters</cookbook/security/voters_data_permission>`. A voter is passed the object

being voted on, which you can use to make complex decisions and effectively

implement your own ACL. Enforcing authorization (e.g. the ``isGranted``

part) will look similar to what you see in this entry, but your voter

.. code-block:: php

interface VoterInterface

{

public function supportsAttribute($attribute);

public function supportsClass($class);

public function vote(TokenInterface $token, $post, array $attributes);

}

The :method:`Symfony\\Component\\Security\\Core\\Authorization\\Voter\\VoterInterface::supportsAttribute`

method is used to check if the voter supports the given user attribute (i.e:

a role like ``ROLE_USER``, an ACL ``EDIT``, etc.).

The :method:`Symfony\\Component\\Security\\Core\\Authorization\\Voter\\VoterInterface::supportsClass`

method is used to check if the voter supports the class of the object whose

access is being checked.

The :method:`Symfony\\Component\\Security\\Core\\Authorization\\Voter\\VoterInterface::vote`

method must implement the business logic that verifies whether or not the

user has access. This method must return one of the following values:

* ``VoterInterface::ACCESS_GRANTED``: The authorization will be granted by this voter;

* ``VoterInterface::ACCESS_ABSTAIN``: The voter cannot decide if authorization should be granted;

* ``VoterInterface::ACCESS_DENIED``: The authorization will be denied by this voter.

:class:`Symfony\\Component\\Security\\Core\\Authorization\\Voter\\VoterInterface`,

which requires the following three methods:

..code-block::php

The ``supportsAttribute()`` method is used to check if the voter supports

the given user attribute (i.e: a role, an ACL, etc.).

The ``supportsClass()`` method is used to check if the voter supports the

class of the object whose access is being checked (doesn't apply to this entry).

The ``vote()`` method must implement the business logic that verifies whether

or not the user is granted access. This method must return one of the following

values:

* ``VoterInterface::ACCESS_GRANTED``: The authorization will be granted by this voter;

* ``VoterInterface::ACCESS_ABSTAIN``: The voter cannot decide if authorization should be granted;

* ``VoterInterface::ACCESS_DENIED``: The authorization will be denied by this voter.

..include::/cookbook/security/voter_interface.rst.inc

In this example, you'll check if the user's IP address matches against a list of

blacklisted addresses and "something" will be the application. If the user's IP is blacklisted, you'll return

..index::

single: Security; Data Permission Voters

How to Use Voters to Check User Permissions

In Symfony2 you can check the permission to access data by using the

:doc:`ACL module</cookbook/security/acl>`, which is a bit overwhelming

for many applications. A much easier solution is to work with custom voters,

which are like simple conditional statements.

..seealso::

Voters can also be used in other ways, like, for example, blacklisting IP

addresses from the entire application::doc:`/cookbook/security/voters`.

..tip::

Take a look at the

:doc:`authorization</components/security/authorization>`

chapter for an even deeper understanding on voters.

How Symfony Uses Voters

In order to use voters, you have to understand how Symfony works with them.

All voters are called each time you use the ``isGranted()`` method on Symfony's

security context (i.e. the ``security.context`` service). Each one decides

if the current user should have access to some resource.

Ultimately, Symfony uses one of three different approaches on what to do

with the feedback from all voters: affirmative, consensus and unanimous.

For more information take a look at

:ref:`the section about access decision managers<components-security-access-decision-manager>`.

The Voter Interface

A custom voter must implement

:class:`Symfony\\Component\\Security\\Core\\Authorization\\Voter\\VoterInterface`,

which has this structure:

..include::/cookbook/security/voter_interface.rst.inc

In this example, the voter will check if the user has access to a specific

object according to your custom conditions (e.g. they must be the owner of

the object). If the condition fails, you'll return

``VoterInterface::ACCESS_DENIED``, otherwise you'll return

``VoterInterface::ACCESS_GRANTED``. In case the responsibility for this decision

does not belong to this voter, it will return ``VoterInterface::ACCESS_ABSTAIN``.

Creating the Custom Voter

The goal is to create a voter that checks if a user has access to view or

edit a particular object. Here's an example implementation:

// src/Acme/DemoBundle/Security/Authorization/Voter/PostVoter.php

namespace Acme\DemoBundle\Security\Authorization\Voter;

use Symfony\Component\Security\Core\Exception\InvalidArgumentException;

use Symfony\Component\DependencyInjection\ContainerInterface;

use Symfony\Component\Security\Core\Authorization\Voter\VoterInterface;

use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;

use Symfony\Component\Security\Core\User\UserInterface;

use Acme\DemoBundle\Entity\Post;

class PostVoter implements VoterInterface

{

const VIEW = 'view';

const EDIT = 'edit';

public function supportsAttribute($attribute)

{

return in_array($attribute, array(

self::VIEW,

self::EDIT,

));

}

public function supportsClass($obj)

{

return $obj instanceof Post;

}

/**

* @var\Acme\DemoBundle\Entity\Post $post

*/

// check if the voter is used correct, only allow one attribute

// this isn't a requirement, it's just one easy way for you to

// design your voter

if(1 !== count($attributes)) {

throw new InvalidArgumentException(

'Only one attribute is allowed for VIEW or EDIT'

);

}

// set the attribute to check against

$attribute = $attributes[0];

// get current logged in user

$user = $token->getUser();

// check if the given attribute is covered by this voter

if (!$this->supportsAttribute($attribute)) {

return VoterInterface::ACCESS_ABSTAIN;

}

// make sure there is a user object (i.e. that the user is logged in)

if (!$user instanceof UserInterface) {

return VoterInterface::ACCESS_DENIED;

}

switch($attribute) {

case 'view':

// the data object could have for example a method isPrivate()

// which checks the Boolean attribute $private

if (!$post->isPrivate()) {

return VoterInterface::ACCESS_GRANTED;

}

break;

case 'edit':

// we assume that our data object has a method getOwner() to

// get the current owner user entity for this data object

if ($user->getId() === $post->getOwner()->getId()) {

return VoterInterface::ACCESS_GRANTED;

}

break;

}

}

}

That's it! The voter is done. The next step is to inject the voter into

the security layer.

Declaring the Voter as a Service

To inject the voter into the security layer, you must declare it as a service

and tag it with ``security.voter``:

..configuration-block::

..code-block::yaml

..code-block::xml

..code-block::php

How to Use the Voter in a Controller

The registered voter will then always be asked as soon as the method ``isGranted()``

from the security context is called.

..code-block::php

It's that easy!