Reduce usage of LD signatures (#9659)

* Do not LDS-sign Follow, Accept, Reject, Undo, Block

* Do not use LDS for Create activities of private toots

* Minor cleanup

* Ignore unsigned activities instead of misattributing them

* Use status.distributable? instead of querying visibility directly

2 files changed, 17 insertions, 9 deletions

diff --git a/app/workers/activitypub/distribution_worker.rb b/app/workers/activitypub/distribution_worker.rb
index 17c1ef7ff..59aacabfd 100644
--- a/app/workers/activitypub/distribution_worker.rb
+++ b/app/workers/activitypub/distribution_worker.rb
@@ -12,7 +12,7 @@ class ActivityPub::DistributionWorker
     return if skip_distribution?
 
     ActivityPub::DeliveryWorker.push_bulk(inboxes) do |inbox_url|
-      [signed_payload, @account.id, inbox_url]
+      [payload, @account.id, inbox_url]
     end
 
     relay! if relayable?
@@ -35,20 +35,24 @@ class ActivityPub::DistributionWorker
   end
 
   def signed_payload
-    @signed_payload ||= Oj.dump(ActivityPub::LinkedDataSignature.new(payload).sign!(@account))
+    Oj.dump(ActivityPub::LinkedDataSignature.new(unsigned_payload).sign!(@account))
   end
 
-  def payload
-    @payload ||= ActiveModelSerializers::SerializableResource.new(
+  def unsigned_payload
+    ActiveModelSerializers::SerializableResource.new(
       @status,
       serializer: ActivityPub::ActivitySerializer,
       adapter: ActivityPub::Adapter
     ).as_json
   end
 
+  def payload
+    @payload ||= @status.distributable? ? signed_payload : Oj.dump(unsigned_payload)
+  end
+
   def relay!
     ActivityPub::DeliveryWorker.push_bulk(Relay.enabled.pluck(:inbox_url)) do |inbox_url|
-      [signed_payload, @account.id, inbox_url]
+      [payload, @account.id, inbox_url]
     end
   end
 end
diff --git a/app/workers/activitypub/reply_distribution_worker.rb b/app/workers/activitypub/reply_distribution_worker.rb
index c0ed3a1f4..892cc1474 100644
--- a/app/workers/activitypub/reply_distribution_worker.rb
+++ b/app/workers/activitypub/reply_distribution_worker.rb
@@ -12,7 +12,7 @@ class ActivityPub::ReplyDistributionWorker
     return unless @account.present? && @status.distributable?
 
     ActivityPub::DeliveryWorker.push_bulk(inboxes) do |inbox_url|
-      [signed_payload, @status.account_id, inbox_url]
+      [payload, @status.account_id, inbox_url]
     end
   rescue ActiveRecord::RecordNotFound
     true
@@ -25,14 +25,18 @@ class ActivityPub::ReplyDistributionWorker
   end
 
   def signed_payload
-    @signed_payload ||= Oj.dump(ActivityPub::LinkedDataSignature.new(payload).sign!(@status.account))
+    Oj.dump(ActivityPub::LinkedDataSignature.new(unsigned_payload).sign!(@status.account))
   end
 
-  def payload
-    @payload ||= ActiveModelSerializers::SerializableResource.new(
+  def unsigned_payload
+    ActiveModelSerializers::SerializableResource.new(
       @status,
       serializer: ActivityPub::ActivitySerializer,
       adapter: ActivityPub::Adapter
     ).as_json
   end
+
+  def payload
+    @payload ||= @status.distributable? ? signed_payload : Oj.dump(unsigned_payload)
+  end
 end