From 4a4d8f0069d9289afe22b5b0ca24fda83a30b4e0 Mon Sep 17 00:00:00 2001
From: Daniel Supernault <danielsupernault@gmail.com>
Date: Wed, 13 Jan 2021 21:38:22 -0700
Subject: [PATCH] Update InboxWorker, fix race condition in account deletes

---
 app/Jobs/InboxPipeline/InboxValidator.php | 52 +++++++++++++++++++++
 app/Jobs/InboxPipeline/InboxWorker.php    | 55 +++++++++++++++++++++--
 2 files changed, 104 insertions(+), 3 deletions(-)

diff --git a/app/Jobs/InboxPipeline/InboxValidator.php b/app/Jobs/InboxPipeline/InboxValidator.php
index 732ad0825..64015f880 100644
--- a/app/Jobs/InboxPipeline/InboxValidator.php
+++ b/app/Jobs/InboxPipeline/InboxValidator.php
@@ -14,6 +14,7 @@ use Illuminate\Foundation\Bus\Dispatchable;
 use Illuminate\Queue\InteractsWithQueue;
 use Illuminate\Queue\SerializesModels;
 use Zttp\Zttp;
+use App\Jobs\DeletePipeline\DeleteRemoteProfilePipeline;
 
 class InboxValidator implements ShouldQueue
 {
@@ -59,6 +60,57 @@ class InboxValidator implements ShouldQueue
             return;
         }
 
+        if( $payload['type'] === 'Delete' &&
+            ( ( is_string($payload['object']) &&
+                $payload['object'] === $payload['actor'] ) ||
+            ( is_array($payload['object']) &&
+              isset($payload['object']['id'], $payload['object']['type']) &&
+              $payload['object']['type'] === 'Person' &&
+              $payload['actor'] === $payload['object']['id']
+            ))
+        ) {
+            $actor = $payload['actor'];
+            $hash = strlen($actor) <= 48 ? 
+                'b:' . base64_encode($actor) :
+                'h:' . hash('sha256', $actor);
+
+            $lockKey = 'ap:inbox:actor-delete-exists:lock:' . $hash;
+            Cache::lock($lockKey, 10)->block(5, function () use(
+                $headers,
+                $payload,
+                $actor,
+                $hash
+            ) {
+                $key = 'ap:inbox:actor-delete-exists:' . $hash;
+                $actorDelete = Cache::remember($key, now()->addMinutes(15), function() use($actor) {
+                    return Profile::whereRemoteUrl($actor)
+                        ->whereNotNull('domain')
+                        ->exists();
+                });
+                if($actorDelete) {
+                    if($this->verifySignature($headers, $payload) == true) {
+                        Cache::set($key, false);
+                        $profile = Profile::whereNotNull('domain')
+                            ->whereNull('status')
+                            ->whereRemoteUrl($actor)
+                            ->first();
+                        if($profile) {
+                            DeleteRemoteProfilePipeline::dispatchNow($profile);
+                        }
+                        return;
+                    } else {
+                        // Signature verification failed, exit.
+                        return;
+                    }
+                } else {
+                    // Remote user doesn't exist, exit early.
+                    return;
+                }
+            });
+
+            return;
+        }
+
         if($profile->status != null) {
             return;
         }
diff --git a/app/Jobs/InboxPipeline/InboxWorker.php b/app/Jobs/InboxPipeline/InboxWorker.php
index c4ddab6e7..efb2c62e9 100644
--- a/app/Jobs/InboxPipeline/InboxWorker.php
+++ b/app/Jobs/InboxPipeline/InboxWorker.php
@@ -14,13 +14,13 @@ use Illuminate\Foundation\Bus\Dispatchable;
 use Illuminate\Queue\InteractsWithQueue;
 use Illuminate\Queue\SerializesModels;
 use Zttp\Zttp;
+use App\Jobs\DeletePipeline\DeleteRemoteProfilePipeline;
 
 class InboxWorker implements ShouldQueue
 {
     use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;
 
     protected $headers;
-    protected $profile;
     protected $payload;
 
     public $timeout = 60;
@@ -56,6 +56,57 @@ class InboxWorker implements ShouldQueue
             return;
         }
 
+        if( $payload['type'] === 'Delete' &&
+            ( ( is_string($payload['object']) &&
+                $payload['object'] === $payload['actor'] ) ||
+            ( is_array($payload['object']) &&
+              isset($payload['object']['id'], $payload['object']['type']) &&
+              $payload['object']['type'] === 'Person' &&
+              $payload['actor'] === $payload['object']['id']
+            ))
+        ) {
+            $actor = $payload['actor'];
+            $hash = strlen($actor) <= 48 ? 
+                'b:' . base64_encode($actor) :
+                'h:' . hash('sha256', $actor);
+
+            $lockKey = 'ap:inbox:actor-delete-exists:lock:' . $hash;
+            Cache::lock($lockKey, 10)->block(5, function () use(
+                $headers,
+                $payload,
+                $actor,
+                $hash
+            ) {
+                $key = 'ap:inbox:actor-delete-exists:' . $hash;
+                $actorDelete = Cache::remember($key, now()->addMinutes(15), function() use($actor) {
+                    return Profile::whereRemoteUrl($actor)
+                        ->whereNotNull('domain')
+                        ->exists();
+                });
+                if($actorDelete) {
+                    if($this->verifySignature($headers, $payload) == true) {
+                        Cache::set($key, false);
+                        $profile = Profile::whereNotNull('domain')
+                            ->whereNull('status')
+                            ->whereRemoteUrl($actor)
+                            ->first();
+                        if($profile) {
+                            DeleteRemoteProfilePipeline::dispatchNow($profile);
+                        }
+                        return;
+                    } else {
+                        // Signature verification failed, exit.
+                        return;
+                    }
+                } else {
+                    // Remote user doesn't exist, exit early.
+                    return;
+                }
+            });
+            
+            return;
+        }
+
         if($this->verifySignature($headers, $payload) == true) {
             (new Inbox($headers, $profile, $payload))->handle();
             return;
@@ -95,12 +146,10 @@ class InboxWorker implements ShouldQueue
         ) {
             if(parse_url($bodyDecoded['object']['attributedTo'], PHP_URL_HOST) !== $keyDomain) {
                 return;
-                abort(400, 'Invalid request');
             }
         }
         if(!$keyDomain || !$idDomain || $keyDomain !== $idDomain) {
             return;
-            abort(400, 'Invalid request');
         }
         $actor = Profile::whereKeyId($keyId)->first();
         if(!$actor) {