From 2420d38b57e1ea3a4235078e1898a8c4c384ff4f Mon Sep 17 00:00:00 2001
From: Alex Pott <alex.a.pott@googlemail.com>
Date: Mon, 17 Apr 2023 10:43:35 +0100
Subject: [PATCH] Issue #3274867 by longwave, jungle, andypost, alexpott,
 smustgrave: Add TrustedCallback attribute

---
 .../Core/Security/Attribute/TrustedCallback.php  |  9 +++++++++
 .../Core/Security/DoTrustedCallbackTrait.php     | 16 +++++++++++++---
 .../Core/Security/DoTrustedCallbackTraitTest.php |  8 ++++++++
 3 files changed, 30 insertions(+), 3 deletions(-)
 create mode 100644 core/lib/Drupal/Core/Security/Attribute/TrustedCallback.php

diff --git a/core/lib/Drupal/Core/Security/Attribute/TrustedCallback.php b/core/lib/Drupal/Core/Security/Attribute/TrustedCallback.php
new file mode 100644
index 00000000000..039fb11aaa3
--- /dev/null
+++ b/core/lib/Drupal/Core/Security/Attribute/TrustedCallback.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Drupal\Core\Security\Attribute;
+
+/**
+ * Attribute to tell that a method is a trusted callback.
+ */
+#[\Attribute(\Attribute::TARGET_METHOD)]
+class TrustedCallback {}
diff --git a/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php b/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php
index 3457cd60ff4..5c1079b9e0c 100644
--- a/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php
+++ b/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php
@@ -2,9 +2,12 @@
 
 namespace Drupal\Core\Security;
 
+use Drupal\Core\Security\Attribute\TrustedCallback;
+
 /**
- * Ensures that TrustedCallbackInterface can be enforced for callback methods.
+ * Ensures that only predefined methods can be used as callback methods.
  *
+ * @see \Drupal\Core\Security\Attribute\TrustedCallback
  * @see \Drupal\Core\Security\TrustedCallbackInterface
  */
 trait DoTrustedCallbackTrait {
@@ -13,8 +16,10 @@ trait DoTrustedCallbackTrait {
    * Performs a callback.
    *
    * If the callback is trusted the callback will occur. Trusted callbacks must
-   * be methods of a class that implements
-   * \Drupal\Core\Security\TrustedCallbackInterface or $extra_trusted_interface
+   * be methods that are tagged with the
+   * \Drupal\Core\Security\Attribute\TrustedCallback attribute, or be methods of
+   * a class that implements
+   * \Drupal\Core\Security\TrustedCallbackInterface or $extra_trusted_interface,
    * or be an anonymous function. If the callback is not trusted then whether or
    * not the callback is called and what type of error is thrown depends on
    * $error_type. To provide time for dependent code to use trusted callbacks
@@ -46,6 +51,7 @@ trait DoTrustedCallbackTrait {
    *   Exception thrown if the callback is not trusted and $error_type equals
    *   TrustedCallbackInterface::THROW_EXCEPTION.
    *
+   * @see \Drupal\Core\Security\Attribute\TrustedCallback
    * @see \Drupal\Core\Security\TrustedCallbackInterface
    */
   public function doTrustedCallback(callable $callback, array $args, $message, $error_type = TrustedCallbackInterface::THROW_EXCEPTION, $extra_trusted_interface = NULL) {
@@ -72,6 +78,10 @@ trait DoTrustedCallbackTrait {
         }
         $safe_callback = in_array($method_name, $methods, TRUE);
       }
+      if (!$safe_callback) {
+        $method = new \ReflectionMethod($object_or_classname, $method_name);
+        $safe_callback = (bool) $method->getAttributes(TrustedCallback::class);
+      }
     }
     elseif ($callback instanceof \Closure) {
       $safe_callback = TRUE;
diff --git a/core/tests/Drupal/Tests/Core/Security/DoTrustedCallbackTraitTest.php b/core/tests/Drupal/Tests/Core/Security/DoTrustedCallbackTraitTest.php
index 91b72fe3717..cab6e8d68d9 100644
--- a/core/tests/Drupal/Tests/Core/Security/DoTrustedCallbackTraitTest.php
+++ b/core/tests/Drupal/Tests/Core/Security/DoTrustedCallbackTraitTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\Core\Security;
 
+use Drupal\Core\Security\Attribute\TrustedCallback;
 use Drupal\Core\Security\TrustedCallbackInterface;
 use Drupal\Core\Security\DoTrustedCallbackTrait;
 use Drupal\Core\Security\UntrustedCallbackException;
@@ -33,8 +34,10 @@ class DoTrustedCallbackTraitTest extends UnitTestCase {
 
     $tests['closure'] = [$closure];
     $tests['TrustedCallbackInterface_object'] = [[new TrustedMethods(), 'callback'], TrustedInterface::class];
+    $tests['TrustedCallbackInterface_object_attribute'] = [[new TrustedMethods(), 'attributeCallback'], TrustedInterface::class];
     $tests['TrustedCallbackInterface_static_string'] = ['\Drupal\Tests\Core\Security\TrustedMethods::callback', TrustedInterface::class];
     $tests['TrustedCallbackInterface_static_array'] = [[TrustedMethods::class, 'callback'], TrustedInterface::class];
+    $tests['TrustedCallbackInterface_static_array_attribute'] = [[TrustedMethods::class, 'attributeCallback'], TrustedInterface::class];
     $tests['extra_trusted_interface_object'] = [[new TrustedObject(), 'callback'], TrustedInterface::class];
     $tests['extra_trusted_interface_static_string'] = ['\Drupal\Tests\Core\Security\TrustedObject::callback', TrustedInterface::class];
     $tests['extra_trusted_interface_static_array'] = [[TrustedObject::class, 'callback'], TrustedInterface::class];
@@ -140,6 +143,11 @@ class TrustedMethods implements TrustedCallbackInterface {
     return 'test';
   }
 
+  #[TrustedCallback]
+  public static function attributeCallback() {
+    return 'test';
+  }
+
   public static function unTrustedCallback() {
     return 'test';
   }