Fix processing LDSigned activities from actors with unknown public keys (#27474)

This commit is contained in:
Claire 2023-10-20 10:45:46 +02:00
parent ff3a9dad0d
commit 1210524a3d
2 changed files with 39 additions and 5 deletions

View file

@ -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?
@ -27,9 +27,9 @@ class ActivityPub::LinkedDataSignature
document_hash = hash(@json.without('signature'))
to_be_verified = options_hash + document_hash
if creator.keypair.public_key.verify(OpenSSL::Digest.new('SHA256'), Base64.decode64(signature), to_be_verified)
creator
end
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)

View file

@ -36,6 +36,40 @@ 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 }