vendor/symfony/src/Symfony/Component/Security/Acl/Domain/PermissionGrantingStrategy.php
changeset 0 7f95f8617b0b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/symfony/src/Symfony/Component/Security/Acl/Domain/PermissionGrantingStrategy.php	Sat Sep 24 15:40:41 2011 +0200
@@ -0,0 +1,209 @@
+<?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\Acl\Domain;
+
+use Symfony\Component\Security\Acl\Exception\NoAceFoundException;
+use Symfony\Component\Security\Acl\Exception\SidNotLoadedException;
+use Symfony\Component\Security\Acl\Model\AclInterface;
+use Symfony\Component\Security\Acl\Model\AuditLoggerInterface;
+use Symfony\Component\Security\Acl\Model\EntryInterface;
+use Symfony\Component\Security\Acl\Model\PermissionGrantingStrategyInterface;
+use Symfony\Component\Security\Acl\Model\SecurityIdentityInterface;
+
+/**
+ * The permission granting strategy to apply to the access control list.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class PermissionGrantingStrategy implements PermissionGrantingStrategyInterface
+{
+    const EQUAL = 'equal';
+    const ALL   = 'all';
+    const ANY   = 'any';
+
+    private $auditLogger;
+
+    /**
+     * Sets the audit logger
+     *
+     * @param AuditLoggerInterface $auditLogger
+     * @return void
+     */
+    public function setAuditLogger(AuditLoggerInterface $auditLogger)
+    {
+        $this->auditLogger = $auditLogger;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function isGranted(AclInterface $acl, array $masks, array $sids, $administrativeMode = false)
+    {
+        try {
+            try {
+                $aces = $acl->getObjectAces();
+
+                if (!$aces) {
+                    throw new NoAceFoundException();
+                }
+
+                return $this->hasSufficientPermissions($acl, $aces, $masks, $sids, $administrativeMode);
+            } catch (NoAceFoundException $noObjectAce) {
+                $aces = $acl->getClassAces();
+
+                if (!$aces) {
+                    throw $noObjectAce;
+                }
+
+                return $this->hasSufficientPermissions($acl, $aces, $masks, $sids, $administrativeMode);
+            }
+        } catch (NoAceFoundException $noClassAce) {
+            if ($acl->isEntriesInheriting() && null !== $parentAcl = $acl->getParentAcl()) {
+                return $parentAcl->isGranted($masks, $sids, $administrativeMode);
+            }
+
+            throw $noClassAce;
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function isFieldGranted(AclInterface $acl, $field, array $masks, array $sids, $administrativeMode = false)
+    {
+        try {
+            try {
+                $aces = $acl->getObjectFieldAces($field);
+                if (!$aces) {
+                    throw new NoAceFoundException();
+                }
+
+                return $this->hasSufficientPermissions($acl, $aces, $masks, $sids, $administrativeMode);
+            } catch (NoAceFoundException $noObjectAces) {
+                $aces = $acl->getClassFieldAces($field);
+                if (!$aces) {
+                    throw $noObjectAces;
+                }
+
+                return $this->hasSufficientPermissions($acl, $aces, $masks, $sids, $administrativeMode);
+            }
+        } catch (NoAceFoundException $noClassAces) {
+            if ($acl->isEntriesInheriting() && null !== $parentAcl = $acl->getParentAcl()) {
+                return $parentAcl->isFieldGranted($field, $masks, $sids, $administrativeMode);
+            }
+
+            throw $noClassAces;
+        }
+    }
+
+    /**
+     * Makes an authorization decision.
+     *
+     * The order of ACEs, and SIDs is significant; the order of permission masks
+     * not so much. It is important to note that the more specific security
+     * identities should be at the beginning of the SIDs array in order for this
+     * strategy to produce intuitive authorization decisions.
+     *
+     * First, we will iterate over permissions, then over security identities.
+     * For each combination of permission, and identity we will test the
+     * available ACEs until we find one which is applicable.
+     *
+     * The first applicable ACE will make the ultimate decision for the
+     * permission/identity combination. If it is granting, this method will return
+     * true, if it is denying, the method will continue to check the next
+     * permission/identity combination.
+     *
+     * This process is repeated until either a granting ACE is found, or no
+     * permission/identity combinations are left. In the latter case, we will
+     * call this method on the parent ACL if it exists, and isEntriesInheriting
+     * is true. Otherwise, we will either throw an NoAceFoundException, or deny
+     * access finally.
+     *
+     * @param AclInterface $acl
+     * @param array        $aces               An array of ACE to check against
+     * @param array        $masks              An array of permission masks
+     * @param array        $sids               An array of SecurityIdentityInterface implementations
+     * @param Boolean      $administrativeMode True turns off audit logging
+     * @return Boolean true, or false; either granting, or denying access respectively.
+     */
+    private function hasSufficientPermissions(AclInterface $acl, array $aces, array $masks, array $sids, $administrativeMode)
+    {
+        $firstRejectedAce  = null;
+
+        foreach ($masks as $requiredMask) {
+            foreach ($sids as $sid) {
+                foreach ($aces as $ace) {
+                    if ($sid->equals($ace->getSecurityIdentity()) && $this->isAceApplicable($requiredMask, $ace)) {
+                        if ($ace->isGranting()) {
+                            if (!$administrativeMode && null !== $this->auditLogger) {
+                                $this->auditLogger->logIfNeeded(true, $ace);
+                            }
+
+                            return true;
+                        }
+
+                        if (null === $firstRejectedAce) {
+                            $firstRejectedAce = $ace;
+                        }
+
+                        break 2;
+                    }
+                }
+            }
+        }
+
+        if (null !== $firstRejectedAce) {
+            if (!$administrativeMode && null !== $this->auditLogger) {
+                $this->auditLogger->logIfNeeded(false, $firstRejectedAce);
+            }
+
+            return false;
+        }
+
+        throw new NoAceFoundException();
+    }
+
+    /**
+     * Determines whether the ACE is applicable to the given permission/security
+     * identity combination.
+     *
+     * Per default, we support three different comparison strategies.
+     *
+     * Strategy ALL:
+     * The ACE will be considered applicable when all the turned-on bits in the
+     * required mask are also turned-on in the ACE mask.
+     *
+     * Strategy ANY:
+     * The ACE will be considered applicable when any of the turned-on bits in
+     * the required mask is also turned-on the in the ACE mask.
+     *
+     * Strategy EQUAL:
+     * The ACE will be considered applicable when the bitmasks are equal.
+     *
+     * @param integer        $requiredMask
+     * @param EntryInterface $ace
+     * @return Boolean
+     */
+    private function isAceApplicable($requiredMask, EntryInterface $ace)
+    {
+        $strategy = $ace->getStrategy();
+        if (self::ALL === $strategy) {
+            return $requiredMask === ($ace->getMask() & $requiredMask);
+        } else if (self::ANY === $strategy) {
+            return 0 !== ($ace->getMask() & $requiredMask);
+        } else if (self::EQUAL === $strategy) {
+            return $requiredMask === $ace->getMask();
+        }
+
+        throw new \RuntimeException(sprintf('The strategy "%s" is not supported.', $strategy));
+    }
+}