--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/database_attachments/database_attachments.php	Thu Jan 04 15:50:29 2018 -0500
@@ -0,0 +1,192 @@
+<?php
+
+/**
+ * Database Attachments
+ *
+ * This plugin which provides database backed storage for temporary
+ * attachment file handling. The primary advantage of this plugin
+ * is its compatibility with round-robin dns multi-server roundcube
+ * installations.
+ *
+ * This plugin relies on the core filesystem_attachments plugin
+ *
+ * @author Ziba Scott <ziba@umich.edu>
+ * @author Aleksander Machniak <alec@alec.pl>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+if (class_exists('filesystem_attachments', false) && !defined('TESTS_DIR')) {
+    die("Configuration issue. There can be only one enabled plugin for attachments handling");
+}
+
+require_once INSTALL_PATH . 'plugins/filesystem_attachments/filesystem_attachments.php';
+
+class database_attachments extends filesystem_attachments
+{
+    // Cache object
+    protected $cache;
+
+    // A prefix for the cache key used in the session and in the key field of the cache table
+    const PREFIX = "ATTACH";
+
+    /**
+     * Save a newly uploaded attachment
+     */
+    function upload($args)
+    {
+        $args['status'] = false;
+
+        $cache = $this->get_cache();
+        $key   = $this->_key($args);
+        $data  = file_get_contents($args['path']);
+
+        if ($data === false) {
+            return $args;
+        }
+
+        $data   = base64_encode($data);
+        $status = $cache->write($key, $data);
+
+        if ($status) {
+            $args['id']     = $key;
+            $args['status'] = true;
+            $args['path']   = null;
+        }
+
+        return $args;
+    }
+
+    /**
+     * Save an attachment from a non-upload source (draft or forward)
+     */
+    function save($args)
+    {
+        $args['status'] = false;
+
+        $cache = $this->get_cache();
+        $key   = $this->_key($args);
+
+        if ($args['path']) {
+            $args['data'] = file_get_contents($args['path']);
+
+            if ($args['data'] === false) {
+                return $args;
+            }
+
+            $args['path'] = null;
+        }
+
+        $data   = base64_encode($args['data']);
+        $status = $cache->write($key, $data);
+
+        if ($status) {
+            $args['id'] = $key;
+            $args['status'] = true;
+        }
+
+        return $args;
+    }
+
+    /**
+     * Remove an attachment from storage
+     * This is triggered by the remove attachment button on the compose screen
+     */
+    function remove($args)
+    {
+        $cache  = $this->get_cache();
+        $status = $cache->remove($args['id']);
+
+        $args['status'] = true;
+
+        return $args;
+    }
+
+    /**
+     * When composing an html message, image attachments may be shown
+     * For this plugin, $this->get() will check the file and
+     * return it's contents
+     */
+    function display($args)
+    {
+        return $this->get($args);
+    }
+
+    /**
+     * When displaying or sending the attachment the file contents are fetched
+     * using this method. This is also called by the attachment_display hook.
+     */
+    function get($args)
+    {
+        $cache = $this->get_cache();
+        $data  = $cache->read($args['id']);
+
+        if ($data !== null && $data !== false) {
+            $args['data'] = base64_decode($data);
+            $args['status'] = true;
+        }
+        else {
+            $args['status'] = false;
+        }
+
+        return $args;
+    }
+
+    /**
+     * Delete all temp files associated with this user
+     */
+    function cleanup($args)
+    {
+        // check if cache object exist, it may be empty on session_destroy (#1489726)
+        if ($cache = $this->get_cache()) {
+            $cache->remove($args['group'], true);
+        }
+    }
+
+    /**
+     * Helper method to generate a unique key for the given attachment file
+     */
+    protected function _key($args)
+    {
+        $uname = $args['path'] ?: $args['name'];
+        return $args['group'] . md5(time() . $uname . $_SESSION['user_id']);
+    }
+
+    /**
+     * Initialize and return cache object
+     */
+    protected function get_cache()
+    {
+        if (!$this->cache) {
+            $this->load_config();
+
+            $rcmail = rcube::get_instance();
+            $ttl    = 12 * 60 * 60; // default: 12 hours
+            $ttl    = $rcmail->config->get('database_attachments_cache_ttl', $ttl);
+            $type   = $rcmail->config->get('database_attachments_cache', 'db');
+            $prefix = self::PREFIX;
+
+            // Add session identifier to the prefix to prevent from removing attachments
+            // in other sessions of the same user (#1490542)
+            if ($id = session_id()) {
+                $prefix .= $id;
+            }
+
+            // Init SQL cache (disable cache data serialization)
+            $this->cache = $rcmail->get_cache($prefix, $type, $ttl, false);
+        }
+
+        return $this->cache;
+    }
+}