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# frozen_string_literal: true
require 'rails_helper'
RSpec.describe ActivityPub::LinkedDataSignature do
include JsonLdHelper
subject { described_class.new(json) }
let!(:sender) { Fabricate(:account, uri: 'http://example.com/alice', domain: 'example.com') }
let(:raw_json) do
{
'@context' => 'https://www.w3.org/ns/activitystreams',
'id' => 'http://example.com/hello-world',
}
end
let(:json) { raw_json.merge('signature' => signature) }
before do
stub_jsonld_contexts!
end
describe '#verify_actor!' do
context 'when signature matches' 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)) }
it 'returns creator' do
expect(subject.verify_actor!).to eq sender
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 }
it 'returns nil' do
expect(subject.verify_actor!).to be_nil
end
end
context 'when signature is tampered' 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' => 's69F3mfddd99dGjmvjdjjs81e12jn121Gkm1') }
it 'returns nil' do
expect(subject.verify_actor!).to be_nil
end
end
end
describe '#sign!' do
subject { described_class.new(raw_json).sign!(sender) }
it 'returns a hash' do
expect(subject).to be_a Hash
end
it 'contains signature' do
expect(subject['signature']).to be_a Hash
expect(subject['signature']['signatureValue']).to be_present
end
it 'can be verified again' do
expect(described_class.new(subject).verify_actor!).to eq sender
end
end
def sign(from_actor, options, document)
options_hash = Digest::SHA256.hexdigest(canonicalize(options.merge('@context' => ActivityPub::LinkedDataSignature::CONTEXT)))
document_hash = Digest::SHA256.hexdigest(canonicalize(document))
to_be_verified = options_hash + document_hash
Base64.strict_encode64(from_actor.keypair.sign(OpenSSL::Digest.new('SHA256'), to_be_verified))
end
end
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