Check cache integrity across execution contexts

(#5465 adapted to master)

.gitignore

@@ -5,6 +5,7 @@
 /config/parameters.yaml
 /tests/config_db*
 /tests/db.yaml
+/tests/parameters.yaml
 /plugins/
 /files/
 /.buildpath

inc/config.class.php

@@ -1516,7 +1516,7 @@ class Config extends CommonDBTM {
    function showPerformanceInformations() {
       global $CONTAINER;
 
-      $cache_storage = $CONTAINER->get('application_cache_storage');
+      $cache_storage = $CONTAINER->get('application_cache')->getStorage();
 
       if (!Config::canUpdate()) {
          return false;

inc/html.class.php

@@ -725,7 +725,7 @@ class Html {
    static function displayDebugInfos($with_session = true, $ajax = false) {
       global $CFG_GLPI, $CONTAINER, $DEBUG_SQL, $SQL_TOTAL_REQUEST, $SQL_TOTAL_TIMER, $DEBUG_AUTOLOAD;
 
-      $cache_storage = $CONTAINER->get('application_cache_storage');
+      $cache_storage = $CONTAINER->get('application_cache')->getStorage();
 
       // Only for debug mode so not need to be translated
       if ($_SESSION['glpi_use_mode'] == Session::DEBUG_MODE) { // mode debug

inc/session.class.php

@@ -624,7 +624,7 @@ class Session {
          $_SESSION['glpipluralnumber'] = $CFG_GLPI["languages"][$trytoload][5];
       }
       $TRANSLATE = new Zend\I18n\Translator\Translator;
-      $cache_storage = $CONTAINER->get('translation_cache_storage');
+      $cache_storage = $CONTAINER->get('translation_cache')->getStorage();
       $TRANSLATE->setCache($cache_storage);
       $TRANSLATE->addTranslationFile('gettext', GLPI_ROOT.$newfile, 'glpi', $trytoload);
 

src/Glpi/Cache/CacheStorageFactory.php

@@ -56,8 +56,8 @@ class CacheStorageFactory extends StorageFactory
     private static $cacheUniqId;
 
     /**
-     * @param string $cacheDir     Cache directory.
-     * @param string $cacheUniqId  Cache unique identifier.
+     * @param string $cacheDir      Cache directory.
+     * @param string $cacheUniqId   Cache unique identifier.
      */
     public function __construct(string $cacheDir, string $cacheUniqId)
     {
@@ -67,36 +67,19 @@ class CacheStorageFactory extends StorageFactory
 
     public static function factory($cfg)
     {
-        // Compute prefered adapter if 'auto' value or no value is used
-        if (!isset($cfg['adapter']) || 'auto' === $cfg['adapter']) {
-            if (function_exists('wincache_ucache_add')) {
-                $cfg['adapter'] = 'wincache';
-            } elseif (function_exists('apcu_fetch')) {
-                $cfg['adapter'] = 'apcu';
-            } else {
-                $cfg['adapter'] = 'filesystem';
-                if (!array_key_exists('plugins', $cfg)) {
-                    $cfg['plugins'] = [
-                        'serializer'
-                    ];
-                } elseif (!in_array('serializer', $cfg['plugins'])) {
-                    $cfg['plugins'][] = 'serializer';
-                }
-            }
-        }
-
-        // Add unique id to namespace
         if (!array_key_exists('options', $cfg) || !is_array($cfg['options'])) {
             $cfg['options'] = [];
         }
-        $baseNamespace = isset($cfg['options']['namespace']) ? $cfg['options']['namespace'] : '_default';
-        $cfg['options']['namespace'] = $baseNamespace . (empty(self::$cacheUniqId) ? '' : '_' . self::$cacheUniqId);
+
+        // Add unique id to namespace
+        $namespace = isset($cfg['options']['namespace']) ? $cfg['options']['namespace'] : '_default';
+        $namespace .= (empty(self::$cacheUniqId) ? '' : '_' . self::$cacheUniqId);
+        $cfg['options']['namespace'] = $namespace;
 
         // Handle pathname for dba adapter
         if ('dba' === $cfg['adapter']) {
             // Assign default value for pathname
             if (!isset($cfg['options']['pathname'])) {
-                $namespace = $cfg['options']['namespace'];
                 $cfg['options']['pathname'] = self::$cacheDir . '/' . $namespace . '.data';
             }
         }
@@ -105,7 +88,6 @@ class CacheStorageFactory extends StorageFactory
         if ('filesystem' === $cfg['adapter']) {
             // Assign default value for cache dir
             if (!isset($cfg['options']['cache_dir'])) {
-                $namespace = $cfg['options']['namespace'];
                 $cfg['options']['cache_dir'] = self::$cacheDir . '/' . $namespace;
             }
 
@@ -130,44 +112,6 @@ class CacheStorageFactory extends StorageFactory
             }
         }
 
-        try {
-            return parent::factory($cfg);
-        } catch (\Exception $e) {
-            if ('filesystem' !== $cfg['adapter']) {
-                // Fallback to 'filesystem' adapter
-                trigger_error(
-                    sprintf(
-                        'Cache adapter instantiation failed, fallback to "filesystem" adapter. Error was "%s".',
-                        $e->getMessage()
-                    ),
-                    E_USER_WARNING
-                );
-                return self::factory(
-                    [
-                        'adapter' => 'filesystem',
-                        'options' => [
-                            'namespace' => $baseNamespace . '_fallback'
-                        ],
-                    ]
-                );
-            } else {
-                // Fallback to 'memory' adapter
-                trigger_error(
-                    sprintf(
-                        'Cache adapter instantiation failed, fallback to "memory" adapter. Error was "%s".',
-                        $e->getMessage()
-                    ),
-                    E_USER_WARNING
-                );
-                return self::factory(
-                    [
-                        'adapter' => 'memory',
-                        'options' => [
-                            'namespace' => $baseNamespace . '_fallback'
-                        ],
-                    ]
-                );
-            }
-        }
+        return parent::factory($cfg);
     }
 }

src/Glpi/Cache/SimpleCache.php

+<?php
+/**
+ * ---------------------------------------------------------------------
+ * GLPI - Gestionnaire Libre de Parc Informatique
+ * Copyright (C) 2015-2018 Teclib' and contributors.
+ *
+ * http://glpi-project.org
+ *
+ * based on GLPI - Gestionnaire Libre de Parc Informatique
+ * Copyright (C) 2003-2014 by the INDEPNET Development Team.
+ *
+ * ---------------------------------------------------------------------
+ *
+ * LICENSE
+ *
+ * This file is part of GLPI.
+ *
+ * GLPI is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GLPI is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GLPI. If not, see <http://www.gnu.org/licenses/>.
+ * ---------------------------------------------------------------------
+ */
+namespace Glpi\Cache;
+
+if (! defined('GLPI_ROOT')) {
+    die("Sorry. You can't access this file directly");
+}
+
+use Zend\Cache\Psr\SimpleCache\SimpleCacheDecorator;
+use Zend\Cache\Storage\StorageInterface;
+
+class SimpleCache extends SimpleCacheDecorator
+{
+    /**
+     * Determines if footprints must be checked.
+     *
+     * @var boolean
+     */
+    private $check_footprints;
+
+    /**
+     * Footprint file path, if existing.
+     *
+     * @var string|null
+     */
+    private $footprint_file;
+
+    /**
+     * Footprint fallback storage used if footprint file is not available.
+     *
+     * @var array
+     */
+    private $footprint_fallback_storage = [];
+
+    /**
+     *
+     * @var StorageInterface
+     */
+    private $storage;
+
+    public function __construct(StorageInterface $storage, $cache_dir, $check_footprints = true)
+    {
+        parent::__construct($storage);
+
+        $this->storage = $storage;
+
+        $this->check_footprints = $check_footprints;
+        if ($this->check_footprints) {
+            $this->footprint_file = $cache_dir . '/' . $storage->getOptions()->getNamespace() . '.json';
+            $this->checkFootprintFileIntegrity();
+        }
+    }
+
+    public function get($key, $default = null)
+    {
+        $cached_value = parent::get($key, $default);
+
+        if (! $this->check_footprints) {
+            return $cached_value;
+        }
+
+        if ($this->getCachedFootprint($key) !== $this->computeFootprint($cached_value)) {
+            // If footprint changed, value is no more valid.
+            return $default;
+        }
+
+        return $cached_value;
+    }
+
+    public function set($key, $value, $ttl = null)
+    {
+        if ($this->check_footprints) {
+            $this->setFootprint($key, $value);
+        }
+
+        return parent::set($key, $value, $ttl);
+    }
+
+    public function delete($key)
+    {
+        if ($this->check_footprints) {
+            $this->setFootprint($key, null);
+        }
+
+        return parent::delete($key);
+    }
+
+    public function clear()
+    {
+        if ($this->check_footprints) {
+            $this->setAllCachedFootprints([]);
+        }
+
+        return parent::clear();
+    }
+
+    public function getMultiple($keys, $default = null)
+    {
+        $cached_values = parent::getMultiple($keys, $default);
+
+        if ($this->check_footprints) {
+            foreach ($cached_values as $key => $cached_value) {
+                if ($this->getCachedFootprint($key) !== $this->computeFootprint($cached_value)) {
+                    // If footprint changed, value is no more valid.
+                    $cached_values[$key] = $default;
+                }
+            }
+        }
+
+        return $cached_values;
+    }
+
+    public function setMultiple($values, $ttl = null)
+    {
+        if ($this->check_footprints) {
+            $this->setMultipleFootprints($values);
+        }
+
+        return parent::setMultiple($values, $ttl);
+    }
+
+    public function deleteMultiple($keys)
+    {
+        if ($this->check_footprints) {
+            $values = array_combine($keys, array_fill(0, count($keys), null));
+            $this->setMultipleFootprints($values);
+        }
+
+        return parent::deleteMultiple($keys);
+    }
+
+    public function has($key)
+    {
+        if (! parent::has($key)) {
+            return false;
+        }
+
+        if (! $this->check_footprints) {
+            return true;
+        }
+
+        // Cache value is not usable if stale, consider it has not existing.
+        return $this->getCachedFootprint($key) === $this->computeFootprint(parent::get($key));
+    }
+
+    /**
+     * Returns storage used for cache.
+     *
+     * @return StorageInterface
+     */
+    public function getStorage(): StorageInterface
+    {
+        return $this->storage;
+    }
+
+    /**
+     * Returns the computed footprint of a value.
+     *
+     * @param mixed $value
+     *
+     * @return string
+     */
+    private function computeFootprint($value)
+    {
+        return sha1(serialize($value));
+    }
+
+    /**
+     * Returns known footprint for a cached item.
+     *
+     * @param string $key
+     *
+     * @return string|null
+     */
+    private function getCachedFootprint($key)
+    {
+        $footprints = $this->getAllCachedFootprints();
+
+        return array_key_exists($key, $footprints) ? $footprints[$key] : null;
+    }
+
+    /**
+     * Defines footprint for cache item.
+     *
+     * @param string $key    Key of the cached item.
+     * @param mixed $values  Value of the cached item.
+     *
+     * @return void
+     */
+    private function setFootprint($key, $value)
+    {
+        $this->setMultipleFootprints([$key => $value]);
+    }
+
+    /**
+     * Defines footprint for multiple cache items.
+     *
+     * @param array $values  Associative array of cached items, where keys corresponds to the
+     *                       cache key of the item and value is its cached value.
+     *
+     * @return void
+     */
+    private function setMultipleFootprints(array $values)
+    {
+        $footprints = $this->getAllCachedFootprints();
+
+        foreach ($values as $key => $value) {
+            $footprints[$key] = $this->computeFootprint($value);
+        }
+
+        $this->setAllCachedFootprints($footprints);
+    }
+
+    /**
+     * Check footprint file integrity, to ensure that it can be used securely.
+     *
+     * @return void
+     */
+    private function checkFootprintFileIntegrity()
+    {
+        if ((file_exists($this->footprint_file) && ! is_writable($this->footprint_file))
+            || (! file_exists($this->footprint_file) && ! is_writable(dirname($this->footprint_file)))) {
+            trigger_error(
+                sprintf('Cannot write "%s" cache footprint file. Cache performance can be lowered.', $this->footprint_file),
+                E_USER_WARNING
+            );
+            $this->footprint_file = null;
+            return;
+        }
+
+        if (! file_exists($this->footprint_file)) {
+            // Create empty array in file if not exists.
+            $this->setAllCachedFootprints([]);
+            return;
+        }
+
+        $file_contents = file_get_contents($this->footprint_file);
+        if (empty($file_contents)) {
+            // Create empty array in file if empty.
+            $this->setAllCachedFootprints([]);
+            return;
+        }
+
+        $footprints = json_decode($file_contents, true);
+        if (json_last_error() !== JSON_ERROR_NONE || ! is_array($footprints)) {
+            // Clear footprint file if not a valid JSON.
+            trigger_error(
+                sprintf('Cache footprint file "%s" contents was invalid, it has been cleaned.', $this->footprint_file),
+                E_USER_WARNING
+            );
+            $this->setAllCachedFootprints([]);
+        }
+    }
+
+    /**
+     * Returns all cache footprints.
+     *
+     * @return array Associative array of cached items footprints, where keys corresponds to the
+     *         cache key of the item and value is its footprint.
+     */
+    private function getAllCachedFootprints()
+    {
+        if (null !== $this->footprint_file) {
+            $file_contents = file_get_contents($this->footprint_file);
+            $footprints = json_decode($file_contents, true);
+
+            if (json_last_error() !== JSON_ERROR_NONE || ! is_array($footprints)) {
+                // Should happen only if file has been corrupted after cache instanciation,
+                // launch integrity tests again to trigger warnings and fix file contents.
+                $this->checkFootprintFileIntegrity();
+                return [];
+            }
+
+            return $footprints;
+        }
+
+        return $this->footprint_fallback_storage;
+    }
+
+    /**
+     * Save all cache footprints.
+     *
+     * @param array $footprints
+     *            Associative array of cached items footprints, where keys corresponds to the
+     *            cache key of the item and value is its footprint.
+     *
+     * @return void
+     */
+    private function setAllCachedFootprints($footprints)
+    {
+        if (null !== $this->footprint_file) {
+            // Remove null values to prevent storage of deleted footprints
+            array_filter(
+                $footprints,
+                function ($val) {
+                    return null !== $val;
+                }
+            );
+
+            $json = json_encode($footprints, JSON_PRETTY_PRINT);
+
+            $handle = fopen($this->footprint_file, 'c');
+
+            $is_locked = flock($handle, LOCK_EX); // Lock the file, if possible (depends on used FS)
+
+            $result = ftruncate($handle, 0)
+                && fwrite($handle, $json)
+                && fflush($handle);
+
+            if ($is_locked) {
+                // Unlock the file if it has been locked
+                flock($handle, LOCK_UN);
+            }
+
+            fclose($handle);
+
+            if ($result !== false) {
+                return;
+            } else {
+                // Should happen only if file is not writable anymore (rights problems or no more disk space),
+                // fallback to singleton storage.
+                $this->footprint_file = null;
+            }
+        }
+
+        $this->footprint_fallback_storage = $footprints;
+    }
+}

src/Glpi/Cache/SimpleCacheFactory.php

+<?php
+/**
+ * ---------------------------------------------------------------------
+ * GLPI - Gestionnaire Libre de Parc Informatique
+ * Copyright (C) 2015-2018 Teclib' and contributors.
+ *
+ * http://glpi-project.org
+ *
+ * based on GLPI - Gestionnaire Libre de Parc Informatique
+ * Copyright (C) 2003-2014 by the INDEPNET Development Team.
+ *
+ * ---------------------------------------------------------------------
+ *
+ * LICENSE
+ *
+ * This file is part of GLPI.
+ *
+ * GLPI is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GLPI is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GLPI. If not, see <http://www.gnu.org/licenses/>.
+ * ---------------------------------------------------------------------
+ */
+
+namespace Glpi\Cache;
+
+use Zend\Cache\Exception\ExceptionInterface;
+
+/**
+ * Glpi simple cache factory.
+ *
+ * @since 10.0.0
+ */
+class SimpleCacheFactory
+{
+    /**
+     * Cache directory.
+     *
+     * @var string
+     */
+    private $cacheDir;
+
+    /**
+     * Force skipping of integrity checks.
+     *
+     * @var bool
+     */
+    private $disableIntegrityChecks;
+
+    /**
+     * Cache storage factory class.
+     *
+     * @var CacheStorageFactory
+     */
+    private $storageFactory;
+
+    /**
+     * @param string              $cacheDir                Cache directory.
+     * @param bool                $disableIntegrityChecks  Force skipping of integrity checks.
+     * @param CacheStorageFactory $storageFactory          Cache storage factory class.
+     */
+    public function __construct(string $cacheDir, bool $disableIntegrityChecks, CacheStorageFactory $storageFactory)
+    {
+        $this->cacheDir = $cacheDir;
+        $this->disableIntegrityChecks = $disableIntegrityChecks;
+        $this->storageFactory = $storageFactory;
+    }
+
+    /**
+     * Create a simple cache instance.
+     *
+     * @param array $cfg  Cache storage configuration, see Zend\Cache\StorageFactory::factory()
+     *
+     * @return SimpleCache
+     */
+    public function factory($cfg): SimpleCache
+    {
+        $isAdapterComputed      = !isset($cfg['adapter']) || 'auto' === $cfg['adapter'];
+        $skipIntegrityChecks = $this->disableIntegrityChecks
+            || (!$isAdapterComputed && $this->canSkipIntegrityChecks($cfg['adapter']));
+
+        // Compute prefered adapter if 'auto' value or no value is used
+        if ($isAdapterComputed) {
+            if (function_exists('wincache_ucache_add')) {
+                $cfg['adapter'] = 'wincache';
+            } elseif (function_exists('apcu_fetch')) {
+                $cfg['adapter'] = 'apcu';
+            } else {
+                $cfg['adapter'] = 'filesystem';
+            }
+        }
+
+        $namespace = isset($cfg['options']) && isset($cfg['options']['namespace'])
+            ? $cfg['options']['namespace']
+            : '_default';
+
+        try {
+            $storage = $this->storageFactory->factory($cfg);
+        } catch (ExceptionInterface $e) {
+            if ($isAdapterComputed && 'filesystem' !== $cfg['adapter']) {
+                // Fallback to 'filesystem' adapter if adapter was not explicitely defined in config
+                trigger_error(
+                    sprintf(
+                        'Cache adapter instantiation failed, fallback to "filesystem" adapter. Error was "%s".',
+                        $e->getMessage()
+                    ),
+                    E_USER_WARNING
+                );
+                $storage = $this->storageFactory->factory(
+                    [
+                        'adapter' => 'filesystem',
+                        'options' => [
+                            'namespace' => $namespace . '_fallback'
+                        ],
+                    ]
+                );
+            } else {
+                // Fallback to 'memory' adapter
+                trigger_error(
+                    sprintf(
+                        'Cache adapter instantiation failed, fallback to "memory" adapter. Error was "%s".',
+                        $e->getMessage()
+                    ),
+                    E_USER_WARNING
+                );
+                $storage = $this->storageFactory->factory(
+                    [
+                        'adapter' => 'memory',
+                        'options' => [
+                            'namespace' => $namespace . '_fallback'
+                        ],
+                    ]