<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\Security\Core\Authorization;
use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
use Symfony\Component\Security\Core\Authorization\Voter\VoterInterface;
use Symfony\Component\Security\Core\Exception\LogicException;
/**
* AccessDecisionManager is the base class for all access decision managers
* that use decision voters.
*
* @author Fabien Potencier <fabien@symfony.com>
*/
class AccessDecisionManager implements AccessDecisionManagerInterface
{
const STRATEGY_AFFIRMATIVE = 'affirmative';
const STRATEGY_CONSENSUS = 'consensus';
const STRATEGY_UNANIMOUS = 'unanimous';
private $voters;
private $strategy;
private $allowIfAllAbstainDecisions;
private $allowIfEqualGrantedDeniedDecisions;
/**
* @param iterable|VoterInterface[] $voters An iterator of VoterInterface instances
* @param string $strategy The vote strategy
* @param bool $allowIfAllAbstainDecisions Whether to grant access if all voters abstained or not
* @param bool $allowIfEqualGrantedDeniedDecisions Whether to grant access if result are equals
*
* @throws \InvalidArgumentException
*/
public function __construct($voters = [], $strategy = self::STRATEGY_AFFIRMATIVE, $allowIfAllAbstainDecisions = false, $allowIfEqualGrantedDeniedDecisions = true)
{
$strategyMethod = 'decide'.ucfirst($strategy);
if ('' === $strategy || !\is_callable([$this, $strategyMethod])) {
throw new \InvalidArgumentException(sprintf('The strategy "%s" is not supported.', $strategy));
}
$this->voters = $voters;
$this->strategy = $strategyMethod;
$this->allowIfAllAbstainDecisions = (bool) $allowIfAllAbstainDecisions;
$this->allowIfEqualGrantedDeniedDecisions = (bool) $allowIfEqualGrantedDeniedDecisions;
}
/**
* Configures the voters.
*
* @param VoterInterface[] $voters An array of VoterInterface instances
*
* @deprecated since version 3.3, to be removed in 4.0. Pass the voters to the constructor instead.
*/
public function setVoters(array $voters)
{
@trigger_error(sprintf('The "%s()" method is deprecated since Symfony 3.3 and will be removed in 4.0. Pass the voters to the constructor instead.', __METHOD__), \E_USER_DEPRECATED);
$this->voters = $voters;
}
/**
* {@inheritdoc}
*/
public function decide(TokenInterface $token, array $attributes, $object = null)
{
return $this->{$this->strategy}($token, $attributes, $object);
}
/**
* Grants access if any voter returns an affirmative response.
*
* If all voters abstained from voting, the decision will be based on the
* allowIfAllAbstainDecisions property value (defaults to false).
*/
private function decideAffirmative(TokenInterface $token, array $attributes, $object = null)
{
$deny = 0;
foreach ($this->voters as $voter) {
$result = $this->vote($voter, $token, $object, $attributes);
if (VoterInterface::ACCESS_GRANTED === $result) {
return true;
}
if (VoterInterface::ACCESS_DENIED === $result) {
++$deny;
}
}
if ($deny > 0) {
return false;
}
return $this->allowIfAllAbstainDecisions;
}
/**
* Grants access if there is consensus of granted against denied responses.
*
* Consensus means majority-rule (ignoring abstains) rather than unanimous
* agreement (ignoring abstains). If you require unanimity, see
* UnanimousBased.
*
* If there were an equal number of grant and deny votes, the decision will
* be based on the allowIfEqualGrantedDeniedDecisions property value
* (defaults to true).
*
* If all voters abstained from voting, the decision will be based on the
* allowIfAllAbstainDecisions property value (defaults to false).
*/
private function decideConsensus(TokenInterface $token, array $attributes, $object = null)
{
$grant = 0;
$deny = 0;
foreach ($this->voters as $voter) {
$result = $this->vote($voter, $token, $object, $attributes);
if (VoterInterface::ACCESS_GRANTED === $result) {
++$grant;
} elseif (VoterInterface::ACCESS_DENIED === $result) {
++$deny;
}
}
if ($grant > $deny) {
return true;
}
if ($deny > $grant) {
return false;
}
if ($grant > 0) {
return $this->allowIfEqualGrantedDeniedDecisions;
}
return $this->allowIfAllAbstainDecisions;
}
/**
* Grants access if only grant (or abstain) votes were received.
*
* If all voters abstained from voting, the decision will be based on the
* allowIfAllAbstainDecisions property value (defaults to false).
*/
private function decideUnanimous(TokenInterface $token, array $attributes, $object = null)
{
$grant = 0;
foreach ($this->voters as $voter) {
foreach ($attributes as $attribute) {
$result = $this->vote($voter, $token, $object, [$attribute]);
if (VoterInterface::ACCESS_DENIED === $result) {
return false;
}
if (VoterInterface::ACCESS_GRANTED === $result) {
++$grant;
}
}
}
// no deny votes
if ($grant > 0) {
return true;
}
return $this->allowIfAllAbstainDecisions;
}
/**
* TokenInterface vote proxy method.
*
* Acts as a BC layer when the VoterInterface is not implemented on the voter.
*
* @deprecated as of 3.4 and will be removed in 4.0. Call the voter directly as the instance will always be a VoterInterface
*/
private function vote($voter, TokenInterface $token, $subject, $attributes)
{
if ($voter instanceof VoterInterface) {
return $voter->vote($token, $subject, $attributes);
}
if (method_exists($voter, 'vote')) {
@trigger_error(sprintf('Calling vote() on an voter without %1$s is deprecated as of 3.4 and will be removed in 4.0. Implement the %1$s on your voter.', VoterInterface::class), \E_USER_DEPRECATED);
// making the assumption that the signature matches
return $voter->vote($token, $subject, $attributes);
}
throw new LogicException(sprintf('"%s" should implement the "%s" interface when used as voter.', \get_class($voter), VoterInterface::class));
}
}