Fix media attachment enumeration

Signed-off-by: Eugen Rochko <eugen@zeonfederated.com>

app/controllers/media_proxy_controller.rb

@@ -2,6 +2,7 @@
 
 class MediaProxyController < ApplicationController
   include RoutingHelper
+  include Authorization
 
   skip_before_action :store_current_location
   skip_before_action :require_functional!
@@ -10,12 +11,14 @@ class MediaProxyController < ApplicationController
 
   rescue_from ActiveRecord::RecordInvalid, with: :not_found
   rescue_from Mastodon::UnexpectedResponseError, with: :not_found
+  rescue_from Mastodon::NotPermittedError, with: :not_found
   rescue_from HTTP::TimeoutError, HTTP::ConnectionError, OpenSSL::SSL::SSLError, with: :internal_server_error
 
   def show
     RedisLock.acquire(lock_options) do |lock|
       if lock.acquired?
-        @media_attachment = MediaAttachment.remote.find(params[:id])
+        @media_attachment = MediaAttachment.remote.attached.find(params[:id])
+        authorize @media_attachment.status, :show?
         redownload! if @media_attachment.needs_redownload? && !reject_media?
       else
         raise Mastodon::RaceConditionError

spec/controllers/media_controller_spec.rb

@@ -28,9 +28,8 @@ describe MediaController do
     end
 
     it 'raises when not permitted to view' do
-      status = Fabricate(:status)
+      status = Fabricate(:status, visibility: :direct)
       media_attachment = Fabricate(:media_attachment, status: status)
-      allow_any_instance_of(MediaController).to receive(:authorize).and_raise(ActiveRecord::RecordNotFound)
       get :show, params: { id: media_attachment.to_param }
 
       expect(response).to have_http_status(404)

spec/controllers/media_proxy_controller_spec.rb

+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe MediaProxyController do
+  render_views
+
+  before do
+    stub_request(:get, 'http://example.com/attachment.png').to_return(request_fixture('avatar.txt'))
+  end
+
+  describe '#show' do
+    it 'redirects when attached to a status' do
+      status = Fabricate(:status)
+      media_attachment = Fabricate(:media_attachment, status: status, remote_url: 'http://example.com/attachment.png')
+      get :show, params: { id: media_attachment.id }
+
+      expect(response).to have_http_status(302)
+    end
+
+    it 'responds with missing when there is not an attached status' do
+      media_attachment = Fabricate(:media_attachment, status: nil, remote_url: 'http://example.com/attachment.png')
+      get :show, params: { id: media_attachment.id }
+
+      expect(response).to have_http_status(404)
+    end
+
+    it 'raises when id cant be found' do
+      get :show, params: { id: 'missing' }
+
+      expect(response).to have_http_status(404)
+    end
+
+    it 'raises when not permitted to view' do
+      status = Fabricate(:status, visibility: :direct)
+      media_attachment = Fabricate(:media_attachment, status: status, remote_url: 'http://example.com/attachment.png')
+      get :show, params: { id: media_attachment.id }
+
+      expect(response).to have_http_status(404)
+    end
+  end
+end