From 5867fad0ba9ec5ef3dd58959399c448c68b49ad1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20=C4=8Ciha=C5=99?= <michal@cihar.com>
Date: Fri, 24 Nov 2017 09:16:45 +0100
Subject: [PATCH] Deny login if two factor is configured, but not available
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Fixes #13832

Signed-off-by: Michal Čihař <michal@cihar.com>
---
 .../classes/Plugins/TwoFactor/Invalid.php     | 63 +++++++++++++++++++
 libraries/classes/TwoFactor.php               |  2 +
 templates/login/twofactor/invalid.twig        |  3 +
 3 files changed, 68 insertions(+)
 create mode 100644 libraries/classes/Plugins/TwoFactor/Invalid.php
 create mode 100644 templates/login/twofactor/invalid.twig

diff --git a/libraries/classes/Plugins/TwoFactor/Invalid.php b/libraries/classes/Plugins/TwoFactor/Invalid.php
new file mode 100644
index 0000000000..c6a42107c3
--- /dev/null
+++ b/libraries/classes/Plugins/TwoFactor/Invalid.php
@@ -0,0 +1,63 @@
+<?php
+/* vim: set expandtab sw=4 ts=4 sts=4: */
+/**
+ * Second authentication factor handling
+ *
+ * @package PhpMyAdmin
+ */
+namespace PhpMyAdmin\Plugins\TwoFactor;
+
+use PhpMyAdmin\Plugins\TwoFactorPlugin;
+use PhpMyAdmin\Template;
+
+/**
+ * Invalid two-factor authentication showing that configured choice is not available.
+ */
+class Invalid extends TwoFactorPlugin
+{
+    /**
+     * @var string
+     */
+    public static $id = 'invalid';
+
+    /**
+     * Checks authentication, returns true on success
+     *
+     * @return boolean
+     */
+    public function check()
+    {
+        return false;
+    }
+
+    /**
+     * Renders user interface to enter two-factor authentication
+     *
+     * @return string HTML code
+     */
+    public function render()
+    {
+        return Template::get('login/twofactor/invalid')->render();
+    }
+
+    /**
+     * Get user visible name
+     *
+     * @return string
+     */
+    public static function getName()
+    {
+        return 'Invalid two-factor authentication';
+    }
+
+    /**
+     * Get user visible description
+     *
+     * @return string
+     */
+    public static function getDescription()
+    {
+        return 'Error fallback only!';
+    }
+}
+
diff --git a/libraries/classes/TwoFactor.php b/libraries/classes/TwoFactor.php
index 6e3de437c7..a0cd5609db 100644
--- a/libraries/classes/TwoFactor.php
+++ b/libraries/classes/TwoFactor.php
@@ -126,6 +126,8 @@ class TwoFactor
         $result = 'PhpMyAdmin\\Plugins\\TwoFactorPlugin';
         if (in_array($name, $this->_available)) {
             $result = 'PhpMyAdmin\\Plugins\\TwoFactor\\' . ucfirst($name);
+        } elseif (! empty($name)) {
+            $result = 'PhpMyAdmin\\Plugins\\TwoFactor\\Invalid';
         }
         return $result;
     }
diff --git a/templates/login/twofactor/invalid.twig b/templates/login/twofactor/invalid.twig
new file mode 100644
index 0000000000..568dd94af4
--- /dev/null
+++ b/templates/login/twofactor/invalid.twig
@@ -0,0 +1,3 @@
+<div class="error">
+{% trans "The configured two factor authentication is not available, please install missing dependencies." %}
+</div>