StEP 1552 closes #1552

Closes #1552

Merge request studip/studip!1137

1 files changed, 114 insertions, 0 deletions

diff --git a/lib/session/DbSessionHandler.php b/lib/session/DbSessionHandler.php
new file mode 100644
index 0000000..05a31a4
--- /dev/null
+++ b/lib/session/DbSessionHandler.php
@@ -0,0 +1,114 @@
+<?php
+/**
+ * Session handler for using Stud.IP database as session storage
+ *
+ * This program 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.
+ *
+ * @author      André Noack <noack@data-quest.de>
+ */
+
+namespace Studip\Session;
+use \DBManager, \Config, \CronjobTask;
+
+class DbSessionHandler implements \SessionHandlerInterface, \SessionIdInterface, \SessionUpdateTimestampHandlerInterface
+{
+
+    private $exists;
+
+    /**
+     * @inheritDoc
+     */
+    public function close(): bool
+    {
+        return true;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function destroy($id): bool
+    {
+        return (bool)DBManager::get()->execute("DELETE FROM session_data WHERE sid = ? LIMIT 1", [$id]);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function gc($max_lifetime): false|int
+    {
+        //bail out if cronjob activated and not called in cli context
+        if (Config::getInstance()->getValue('CRONJOBS_ENABLE')
+            && ($task = array_pop(CronjobTask::findByClass('SessionGcJob')))
+            && count($task->schedules->findBy('active', 1))
+            && PHP_SAPI !== 'cli'
+        ) {
+            return false;
+        }
+        return DBManager::get()->execute("DELETE FROM session_data WHERE changed < FROM_UNIXTIME(?) ", [time() - $max_lifetime]);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function open($path, $name): bool
+    {
+        return true;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    #[\ReturnTypeWillChange]
+    public function read($id)
+    {
+        $str = DBManager::get()->fetchColumn("SELECT val FROM session_data where sid  = ?", [$id]);
+        if ($str) {
+            $this->exists = $id;
+        }
+        return (string)$str;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function write($id, $data): bool
+    {
+        $db = DBManager::get();
+        if ($this->exists === $id) {
+            $stmt = $db->prepare("UPDATE session_data SET val = ? WHERE sid = ?");
+        } else {
+            $stmt = $db->prepare("REPLACE INTO session_data ( val, sid ) VALUES (?, ?)");
+        }
+        return (bool) $stmt->execute([$data, $id]);
+    }
+
+    public function exists($id)
+    {
+        return (bool)DBManager::get()->fetchColumn("SELECT 1 FROM session_data where sid  = ?", [$id]);
+    }
+
+    public function create_sid(): string
+    {
+        do {
+            $new_id = md5(bin2hex(random_bytes(128)));
+        } while ($this->exists($new_id));
+        $this->exists = null;
+        return $new_id;
+    }
+
+    public function updateTimestamp(string $id, string $data): bool
+    {
+        DBManager::get()->execute("UPDATE session_data SET changed = CURRENT_TIMESTAMP() WHERE sid = ?", [$id]);
+        return true;
+    }
+
+    public function validateId(string $id): bool
+    {
+        return (bool)$this->exists($id);
+    }
+
+
+}