Update flask_wtf to 0.14.2 and make CSRFProtect available to current_app

By default CSRF protection is disabled for all views, since most
web endpoints and all API endpoints do not need it.
On the views that require it, we use the 
current_app.csrf.protect() method.

pillar/__init__.py

@@ -73,6 +73,7 @@ class PillarServer(BlinkerCompatibleEve):
     def __init__(self, app_root, **kwargs):
         from .extension import PillarExtension
         from celery import Celery
+        from flask_wtf.csrf import CSRFProtect
 
         kwargs.setdefault('validator', custom_field_validation.ValidateCustomFields)
         super(PillarServer, self).__init__(settings=empty_settings, **kwargs)
@@ -141,6 +142,10 @@ class PillarServer(BlinkerCompatibleEve):
 
         self.before_first_request(self.setup_db_indices)
 
+        # Make CSRF protection available to the application. By default it is
+        # disabled on all endpoints. More info at WTF_CSRF_CHECK_DEFAULT in config.py
+        self.csrf = CSRFProtect(self)
+
     def _validate_config(self):
         if not self.config.get('SECRET_KEY'):
             raise ConfigurationMissingError('SECRET_KEY configuration key is missing')

pillar/config.py

@@ -255,3 +255,8 @@ SEND_FILE_MAX_AGE_DEFAULT = 3600 * 24 * 365  # seconds
 # be used. Note that this causes extra traffic, since every time the process
 # restarts the URLs will be different.
 STATIC_FILE_HASH = ''
+
+# Disable default CSRF protection for all views, since most web endpoints and
+# all API endpoints do not need it. On the views that require it, we use the
+# current_app.csrf.protect() method.
+WTF_CSRF_CHECK_DEFAULT = False

pillar/web/nodes/routes.py

@@ -487,9 +487,8 @@ def preview_markdown():
     content of a node.
     """
 
-    if not validate_csrf(request.headers.get('X-CSRFToken')):
-        return jsonify({'_status': 'ERR',
-                        'message': 'CSRF validation failed.'}), 403
+    current_app.csrf.protect()
+
     try:
         content = request.form['content']
     except KeyError:

requirements.txt

@@ -16,7 +16,7 @@ Flask-Babel==0.11.2
 Flask-Cache==0.13.1
 Flask-Script==2.0.6
 Flask-Login==0.3.2
-Flask-WTF==0.12
+Flask-WTF==0.14.2
 gcloud==0.12.0
 google-apitools==0.4.11
 httplib2==0.9.2

setup.py

@@ -39,7 +39,7 @@ setuptools.setup(
         'Flask-Script>=2.0.5',
         'Flask-Login>=0.3.2',
         'Flask-OAuthlib>=0.9.3',
-        'Flask-WTF>=0.12',
+        'Flask-WTF>=0.14.2',
         'algoliasearch>=1.12.0',
 
         # Limit the major version to the major version of ElasticSearch we're using.

src/templates/layout.pug

@@ -87,7 +87,16 @@ html(lang="en")
 		| {% block footer_scripts_pre %}{% endblock %}
 		| {% block footer_scripts %}{% endblock %}
 
-
+		script.
+			// When sending an AJAX request, always add the X-CSRFToken header to it.
+			var csrf_token = "{{ csrf_token() }}";
+			$.ajaxSetup({
+				beforeSend: function (xhr, settings) {
+					if (!/^(GET|HEAD|OPTIONS|TRACE)$/i.test(settings.type) && !this.crossDomain) {
+						xhr.setRequestHeader("X-CSRFToken", csrf_token);
+					}
+				}
+			});
 
 		script.
 			(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){