Add event to allow custom user password validation

framework/core/src/Core/User.php

@@ -15,6 +15,7 @@ use Flarum\Core\Access\Gate;
 use Flarum\Core\Support\EventGeneratorTrait;
 use Flarum\Core\Support\ScopeVisibilityTrait;
 use Flarum\Database\AbstractModel;
+use Flarum\Event\CheckUserPassword;
 use Flarum\Event\ConfigureUserPreferences;
 use Flarum\Event\PostWasDeleted;
 use Flarum\Event\PrepareUserGroups;
@@ -340,6 +341,12 @@ class User extends AbstractModel
      */
     public function checkPassword($password)
     {
+        $valid = static::$dispatcher->until(new CheckUserPassword($this, $password));
+
+        if ($valid !== null) {
+            return $valid;
+        }
+
         return static::$hasher->check($password, $this->password);
     }
 

framework/core/src/Event/CheckUserPassword.php

@@ -0,0 +1,36 @@
+<?php
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Flarum\Event;
+
+use Flarum\Core\User;
+
+class CheckUserPassword
+{
+    /**
+     * @var User
+     */
+    public $user;
+
+    /**
+     * @var string
+     */
+    public $password;
+
+    /**
+     * @param User $user
+     * @param string $password
+     */
+    public function __construct($user, $password)
+    {
+        $this->user = $user;
+        $this->password = $password;
+    }
+}