FEATURE: Support for a whitelist for embeddable host paths

app/assets/javascripts/admin/components/embeddable-host.js.es6

@@ -30,10 +30,11 @@ export default Ember.Component.extend(bufferedProperty('host'), {
     save() {
       if (this.get('cantSave')) { return; }
 
-      const props = this.get('buffered').getProperties('host');
+      const props = this.get('buffered').getProperties('host', 'path_whitelist');
       props.category_id = this.get('categoryId');
 
       const host = this.get('host');
+
       host.save(props).then(() => {
         host.set('category', Discourse.Category.findById(this.get('categoryId')));
         this.set('editToggled', false);

app/assets/javascripts/admin/templates/components/embeddable-host.hbs

@@ -2,6 +2,9 @@
   <td>
     {{input value=buffered.host placeholder="example.com" enter="save" class="host-name"}}
   </td>
+  <td>
+    {{input value=buffered.path_whitelist placeholder="/blog/.*" enter="save" class="path-whitelist"}}
+  </td>
   <td>
     {{category-chooser value=categoryId}}
   </td>
@@ -11,6 +14,7 @@
   </td>
 {{else}}
   <td>{{host.host}}</td>
+  <td>{{host.path_whitelist}}</td>
   <td>{{category-badge host.category}}</td>
   <td>
     {{d-button icon="pencil" action="edit"}}

app/assets/javascripts/admin/templates/embedding.hbs

@@ -2,9 +2,10 @@
   {{#if embedding.embeddable_hosts}}
     <table class='embedding'>
       <tr>
-        <th style='width: 50%'>{{i18n "admin.embedding.host"}}</th>
+        <th style='width: 30%'>{{i18n "admin.embedding.host"}}</th>
+        <th style='width: 30%'>{{i18n "admin.embedding.path_whitelist"}}</th>
         <th style='width: 30%'>{{i18n "admin.embedding.category"}}</th>
-        <th style='width: 20%'>&nbsp;</th>
+        <th style='width: 10%'>&nbsp;</th>
       </tr>
       {{#each embedding.embeddable_hosts as |host|}}
         {{embeddable-host host=host deleteHost="deleteHost"}}

app/controllers/admin/embeddable_hosts_controller.rb

@@ -21,6 +21,7 @@ class Admin::EmbeddableHostsController < Admin::AdminController
 
     def save_host(host)
       host.host = params[:embeddable_host][:host]
+      host.path_whitelist = params[:embeddable_host][:path_whitelist]
       host.category_id = params[:embeddable_host][:category_id]
       host.category_id = SiteSetting.uncategorized_category_id if host.category_id.blank?
 

app/controllers/embed_controller.rb

@@ -85,7 +85,7 @@ class EmbedController < ApplicationController
     def ensure_embeddable
 
       if !(Rails.env.development? && current_user.try(:admin?))
-        raise Discourse::InvalidAccess.new('invalid referer host') unless EmbeddableHost.host_allowed?(request.referer)
+        raise Discourse::InvalidAccess.new('invalid referer host') unless EmbeddableHost.url_allowed?(request.referer)
       end
 
       response.headers['X-Frame-Options'] = "ALLOWALL"

app/models/embeddable_host.rb

@@ -7,8 +7,11 @@ class EmbeddableHost < ActiveRecord::Base
     self.host.sub!(/\/.*$/, '')
   end
 
-  def self.record_for_host(host)
-    uri = URI(host) rescue nil
+  def self.record_for_url(uri)
+
+    if uri.is_a?(String)
+      uri = URI(uri) rescue nil
+    end
     return false unless uri.present?
 
     host = uri.host
@@ -17,8 +20,13 @@ class EmbeddableHost < ActiveRecord::Base
     where("lower(host) = ?", host).first
   end
 
-  def self.host_allowed?(host)
-    record_for_host(host).present?
+  def self.url_allowed?(url)
+    uri = URI(url) rescue nil
+    return false unless uri.present?
+
+    host = record_for_url(uri)
+    return host.present? &&
+           (host.path_whitelist.blank? || !Regexp.new(host.path_whitelist).match(uri.path).nil?)
   end
 
   private

app/models/topic_embed.rb

@@ -33,7 +33,7 @@ class TopicEmbed < ActiveRecord::Base
     # If there is no embed, create a topic, post and the embed.
     if embed.blank?
       Topic.transaction do
-        eh = EmbeddableHost.record_for_host(url)
+        eh = EmbeddableHost.record_for_url(url)
 
         creator = PostCreator.new(user,
                                   title: title,

app/serializers/embeddable_host_serializer.rb

@@ -1,16 +1,11 @@
 class EmbeddableHostSerializer < ApplicationSerializer
-  attributes :id, :host, :category_id
 
-  def id
-    object.id
+  TO_SERIALIZE = [:id, :host, :path_whitelist, :category_id]
+
+  attributes *TO_SERIALIZE
+
+  TO_SERIALIZE.each do |attr|
+    define_method(attr) { object.send(attr) }
   end
 
-  def host
-    object.host
-  end
-
-  def category_id
-    object.category_id
-  end
 end
-

config/locales/client.en.yml

@@ -3113,6 +3113,7 @@ en:
         sample: "Use the following HTML code into your site to create and embed discourse topics. Replace <b>REPLACE_ME</b> with the canonical URL of the page you are embedding it on."
         title: "Embedding"
         host: "Allowed Hosts"
+        path_whitelist: "Path Whitelist"
         edit: "edit"
         category: "Post to Category"
         add_host: "Add Host"

lib/topic_retriever.rb

@@ -7,13 +7,13 @@ class TopicRetriever
   end
 
   def retrieve
-    perform_retrieve unless (invalid_host? || retrieved_recently?)
+    perform_retrieve unless (invalid_url? || retrieved_recently?)
   end
 
   private
 
-    def invalid_host?
-      !EmbeddableHost.host_allowed?(@embed_url)
+    def invalid_url?
+      !EmbeddableHost.url_allowed?(@embed_url)
     end
 
     def retrieved_recently?

spec/components/topic_retriever_spec.rb

@@ -10,7 +10,7 @@ describe TopicRetriever do
   describe "#retrieve" do
     context "when host is invalid" do
       before do
-        topic_retriever.stubs(:invalid_host?).returns(true)
+        topic_retriever.stubs(:invalid_url?).returns(true)
       end
 
       it "does not perform_retrieve" do
@@ -32,7 +32,7 @@ describe TopicRetriever do
 
     context "when host is not invalid" do
         before do
-          topic_retriever.stubs(:invalid_host?).returns(false)
+          topic_retriever.stubs(:invalid_url?).returns(false)
         end
 
       context "when topics have been retrieived recently" do

spec/models/embeddable_host_spec.rb

@@ -49,19 +49,28 @@ describe EmbeddableHost do
     expect(eh).not_to be_valid
   end
 
-  describe "allows_embeddable_host" do
+  describe "url_allowed?" do
     let!(:host) { Fabricate(:embeddable_host) }
 
     it 'works as expected' do
-      expect(EmbeddableHost.host_allowed?('http://eviltrout.com')).to eq(true)
-      expect(EmbeddableHost.host_allowed?('https://eviltrout.com')).to eq(true)
-      expect(EmbeddableHost.host_allowed?('https://not-eviltrout.com')).to eq(false)
+      expect(EmbeddableHost.url_allowed?('http://eviltrout.com')).to eq(true)
+      expect(EmbeddableHost.url_allowed?('https://eviltrout.com')).to eq(true)
+      expect(EmbeddableHost.url_allowed?('https://not-eviltrout.com')).to eq(false)
     end
 
     it 'works with multiple hosts' do
       Fabricate(:embeddable_host, host: 'discourse.org')
-      expect(EmbeddableHost.host_allowed?('http://eviltrout.com')).to eq(true)
-      expect(EmbeddableHost.host_allowed?('http://discourse.org')).to eq(true)
+      expect(EmbeddableHost.url_allowed?('http://eviltrout.com')).to eq(true)
+      expect(EmbeddableHost.url_allowed?('http://discourse.org')).to eq(true)
+    end
+  end
+
+  describe "path_whitelist" do
+    let!(:host) { Fabricate(:embeddable_host, path_whitelist: '^/fp/\d{4}/\d{2}/\d{2}/.*$') }
+
+    it "matches the path" do
+      expect(EmbeddableHost.url_allowed?('http://eviltrout.com')).to eq(false)
+      expect(EmbeddableHost.url_allowed?('http://eviltrout.com/fp/2016/08/25/test-page')).to eq(true)
     end
 
   end