From 13688539bc7bfb3ffef86b3fd41b37671861c17f Mon Sep 17 00:00:00 2001
From: Claire <claire.github-309c@sitedethib.com>
Date: Fri, 20 Oct 2023 10:45:46 +0200
Subject: [PATCH] Fix processing LDSigned activities from actors with unknown
public keys (#27474)
---
app/lib/activitypub/linked_data_signature.rb | 6 ++--
.../activitypub/linked_data_signature_spec.rb | 34 +++++++++++++++++++
2 files changed, 38 insertions(+), 2 deletions(-)
diff --git a/app/lib/activitypub/linked_data_signature.rb b/app/lib/activitypub/linked_data_signature.rb
index ea59879f3..faea63e8f 100644
--- a/app/lib/activitypub/linked_data_signature.rb
+++ b/app/lib/activitypub/linked_data_signature.rb
@@ -18,8 +18,8 @@ class ActivityPub::LinkedDataSignature
return unless type == 'RsaSignature2017'
- creator = ActivityPub::TagManager.instance.uri_to_actor(creator_uri)
- creator ||= ActivityPub::FetchRemoteKeyService.new.call(creator_uri, id: false)
+ creator = ActivityPub::TagManager.instance.uri_to_actor(creator_uri)
+ creator = ActivityPub::FetchRemoteKeyService.new.call(creator_uri, id: false) if creator&.public_key.blank?
return if creator.nil?
@@ -28,6 +28,8 @@ class ActivityPub::LinkedDataSignature
to_be_verified = options_hash + document_hash
creator if creator.keypair.public_key.verify(OpenSSL::Digest.new('SHA256'), Base64.decode64(signature), to_be_verified)
+ rescue OpenSSL::PKey::RSAError
+ false
end
def sign!(creator, sign_with: nil)
diff --git a/spec/lib/activitypub/linked_data_signature_spec.rb b/spec/lib/activitypub/linked_data_signature_spec.rb
index d5b713b34..97268eea6 100644
--- a/spec/lib/activitypub/linked_data_signature_spec.rb
+++ b/spec/lib/activitypub/linked_data_signature_spec.rb
@@ -34,6 +34,40 @@ RSpec.describe ActivityPub::LinkedDataSignature do
end
end
+ context 'when local account record is missing a public key' do
+ let(:raw_signature) do
+ {
+ 'creator' => 'http://example.com/alice',
+ 'created' => '2017-09-23T20:21:34Z',
+ }
+ end
+
+ let(:signature) { raw_signature.merge('type' => 'RsaSignature2017', 'signatureValue' => sign(sender, raw_signature, raw_json)) }
+
+ let(:service_stub) { instance_double(ActivityPub::FetchRemoteKeyService) }
+
+ before do
+ # Ensure signature is computed with the old key
+ signature
+
+ # Unset key
+ old_key = sender.public_key
+ sender.update!(private_key: '', public_key: '')
+
+ allow(ActivityPub::FetchRemoteKeyService).to receive(:new).and_return(service_stub)
+
+ allow(service_stub).to receive(:call).with('http://example.com/alice', id: false) do
+ sender.update!(public_key: old_key)
+ sender
+ end
+ end
+
+ it 'fetches key and returns creator' do
+ expect(subject.verify_actor!).to eq sender
+ expect(service_stub).to have_received(:call).with('http://example.com/alice', id: false).once
+ end
+ end
+
context 'when signature is missing' do
let(:signature) { nil }