--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/program/lib/Roundcube/rcube_session_redis.php	Thu Jan 04 15:52:31 2018 -0500
@@ -0,0 +1,209 @@
+<?php
+
+/**
+ +-----------------------------------------------------------------------+
+ | This file is part of the Roundcube Webmail client                     |
+ | Copyright (C) 2005-2014, The Roundcube Dev Team                       |
+ |                                                                       |
+ | Licensed under the GNU General Public License version 3 or            |
+ | any later version with exceptions for skins & plugins.                |
+ | See the README file for a full license statement.                     |
+ |                                                                       |
+ | PURPOSE:                                                              |
+ |   Provide redis supported session management                          |
+ +-----------------------------------------------------------------------+
+ | Author: Cor Bosman <cor@roundcu.be>                                   |
+ +-----------------------------------------------------------------------+
+*/
+
+/**
+ * Class to provide redis session storage
+ *
+ * @package    Framework
+ * @subpackage Core
+ * @author     Cor Bosman <cor@roundcu.be>
+ */
+class rcube_session_redis extends rcube_session {
+
+    private $redis;
+
+    /**
+     * @param Object $config
+     */
+    public function __construct($config)
+    {
+        parent::__construct($config);
+
+        // instantiate Redis object
+        $this->redis = new Redis();
+
+        if (!$this->redis) {
+            rcube::raise_error(array('code' => 604, 'type' => 'session',
+                                   'line' => __LINE__, 'file' => __FILE__,
+                                   'message' => "Failed to find Redis. Make sure php-redis is included"),
+                               true, true);
+        }
+
+        // get config instance
+        $hosts = $this->config->get('redis_hosts', array('localhost'));
+
+        // host config is wrong
+        if (!is_array($hosts) || empty($hosts)) {
+            rcube::raise_error(array('code' => 604, 'type' => 'session',
+                                   'line' => __LINE__, 'file' => __FILE__,
+                                   'message' => "Redis host not configured"),
+                               true, true);
+        }
+
+        // only allow 1 host for now until we support clustering
+        if (count($hosts) > 1) {
+            rcube::raise_error(array('code' => 604, 'type' => 'session',
+                                   'line' => __LINE__, 'file' => __FILE__,
+                                   'message' => "Redis cluster not yet supported"),
+                               true, true);
+        }
+
+        foreach ($hosts as $host) {
+            // explode individual fields
+            list($host, $port, $database, $password) = array_pad(explode(':', $host, 4), 4, null);
+
+            // set default values if not set
+            $host = ($host !== null) ? $host : '127.0.0.1';
+            $port = ($port !== null) ? $port : 6379;
+            $database = ($database !== null) ? $database : 0;
+
+            if ($this->redis->connect($host, $port) === false) {
+                rcube::raise_error(
+                    array(
+                        'code' => 604,
+                        'type' => 'session',
+                        'line' => __LINE__,
+                        'file' => __FILE__,
+                        'message' => "Could not connect to Redis server. Please check host and port"
+                    ),
+                    true,
+                    true
+                );
+            }
+
+            if ($password != null && $this->redis->auth($password) === false) {
+                rcube::raise_error(
+                    array(
+                        'code' => 604,
+                        'type' => 'session',
+                        'line' => __LINE__,
+                        'file' => __FILE__,
+                        'message' => "Could not authenticate with Redis server. Please check password."
+                    ),
+                    true,
+                    true
+                );
+            }
+
+            if ($database != 0 && $this->redis->select($database) === false) {
+                rcube::raise_error(
+                    array(
+                        'code' => 604,
+                        'type' => 'session',
+                        'line' => __LINE__,
+                        'file' => __FILE__,
+                        'message' => "Could not select Redis database. Please check database setting."
+                    ),
+                    true,
+                    true
+                );
+            }
+        }
+
+        // register sessions handler
+        $this->register_session_handler();
+    }
+
+    /**
+     * @param $save_path
+     * @param $session_name
+     * @return bool
+     */
+    public function open($save_path, $session_name)
+    {
+        return true;
+    }
+
+    /**
+     * @return bool
+     */
+    public function close()
+    {
+        return true;
+    }
+
+    /**
+     * remove data from store
+     *
+     * @param $key
+     * @return bool
+     */
+    public function destroy($key)
+    {
+        if ($key) {
+            $this->redis->del($key);
+        }
+
+        return true;
+    }
+
+    /**
+     * read data from redis store
+     *
+     * @param $key
+     * @return null
+     */
+    public function read($key)
+    {
+        if ($value = $this->redis->get($key)) {
+            $arr = unserialize($value);
+            $this->changed = $arr['changed'];
+            $this->ip      = $arr['ip'];
+            $this->vars    = $arr['vars'];
+            $this->key     = $key;
+
+            return !empty($this->vars) ? (string) $this->vars : '';
+        }
+
+        return '';
+    }
+
+    /**
+     * write data to redis store
+     *
+     * @param $key
+     * @param $newvars
+     * @param $oldvars
+     * @return bool
+     */
+    public function update($key, $newvars, $oldvars)
+    {
+        $ts = microtime(true);
+
+        if ($newvars !== $oldvars || $ts - $this->changed > $this->lifetime / 3) {
+            $data = serialize(array('changed' => time(), 'ip' => $this->ip, 'vars' => $newvars));
+            $this->redis->setex($key, $this->lifetime + 60, $data);
+        }
+
+        return true;
+    }
+
+    /**
+     * write data to redis store
+     *
+     * @param $key
+     * @param $vars
+     * @return bool
+     */
+    public function write($key, $vars)
+    {
+        $data = serialize(array('changed' => time(), 'ip' => $this->ip, 'vars' => $vars));
+
+        return $this->redis->setex($key, $this->lifetime + 60, $data);
+    }
+}