Backend and frontend protection against csrf attacks:

- root resources changes the csrf token cookie everytime it is loaded, in particular during the intestitial load during login
- it will also add that cookie on single user mode
- initialize will still load all resources
- but they you cant access them if the csrf token do not match
- all ajax calls needs to add the token to the header
- non ajax get requests do not need xsrf token validation
- non ajax post will have to send the token in as a form input or in the content

Issue #612

12 files changed, 225 insertions, 40 deletions

diff --git a/service/pixelated/resources/__init__.py b/service/pixelated/resources/__init__.py
index 14ecac86..469c8bc8 100644
--- a/service/pixelated/resources/__init__.py
+++ b/service/pixelated/resources/__init__.py
@@ -99,3 +99,7 @@ class UnAuthorizedResource(Resource):
     def render_GET(self, request):
         request.setResponseCode(UNAUTHORIZED)
         return "Unauthorized!"
+
+    def render_POST(self, request):
+        request.setResponseCode(UNAUTHORIZED)
+        return "Unauthorized!"
diff --git a/service/pixelated/resources/login_resource.py b/service/pixelated/resources/login_resource.py
index f1d9c1e3..aca266cf 100644
--- a/service/pixelated/resources/login_resource.py
+++ b/service/pixelated/resources/login_resource.py
@@ -20,14 +20,13 @@ from xml.sax import SAXParseException
 
 from twisted.cred import credentials
 from twisted.internet import defer
+from twisted.python.filepath import FilePath
 from twisted.web import util
-from twisted.web.error import FlattenerError
 from twisted.web.http import UNAUTHORIZED, OK
 from twisted.web.resource import IResource, NoResource
 from twisted.web.server import NOT_DONE_YET
 from twisted.web.static import File
 from twisted.web.template import Element, XMLFile, renderElement, renderer
-from twisted.python.filepath import FilePath
 
 from pixelated.adapter.welcome_mail import add_welcome_mail
 from pixelated.resources import BaseResource, UnAuthorizedResource, IPixelatedSession
diff --git a/service/pixelated/resources/root_resource.py b/service/pixelated/resources/root_resource.py
index 6e619951..2c32ab0c 100644
--- a/service/pixelated/resources/root_resource.py
+++ b/service/pixelated/resources/root_resource.py
@@ -13,11 +13,12 @@
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with Pixelated. If not, see <http://www.gnu.org/licenses/>.
-
+import hashlib
+import json
 import os
 from string import Template
 
-from pixelated.resources import BaseResource
+from pixelated.resources import BaseResource, UnAuthorizedResource
 from pixelated.resources.attachments_resource import AttachmentsResource
 from pixelated.resources.contacts_resource import ContactsResource
 from pixelated.resources.features_resource import FeaturesResource
@@ -29,22 +30,22 @@ from pixelated.resources.mail_resource import MailResource
 from pixelated.resources.mails_resource import MailsResource
 from pixelated.resources.tags_resource import TagsResource
 from pixelated.resources.keys_resource import KeysResource
-from twisted.web.resource import Resource
 from twisted.web.static import File
 
+CSRF_TOKEN_LENGTH = 32
 
 MODE_STARTUP = 1
 MODE_RUNNING = 2
 
 
 class RootResource(BaseResource):
-
     def __init__(self, services_factory):
         BaseResource.__init__(self, services_factory)
         self._startup_assets_folder = self._get_startup_folder()
         self._static_folder = self._get_static_folder()
         self._html_template = open(os.path.join(self._static_folder, 'index.html')).read()
         self._services_factory = services_factory
+        self.child_resources = ChildResourcesMap()
         self._startup_mode()
 
     def _startup_mode(self):
@@ -54,21 +55,39 @@ class RootResource(BaseResource):
     def getChild(self, path, request):
         if path == '':
             return self
-        return Resource.getChild(self, path, request)
+        if self._is_xsrf_valid(request):
+            return self.child_resources.get(path)
+        return UnAuthorizedResource()
+
+    def _is_xsrf_valid(self, request):
+        xsrf_token = request.getCookie('XSRF-TOKEN')
+
+        ajax_request = (request.getHeader('x-requested-with') == 'XMLHttpRequest')
+        if ajax_request:
+            xsrf_header = request.getHeader('x-xsrf-token')
+            return xsrf_header and xsrf_header == xsrf_token
+
+        get_request = (request.method == 'GET')
+        if get_request:
+            return True
+
+        csrf_input = request.args.get('csrftoken', [None])[0] or json.loads(request.content.read()).get('csrftoken', [None])[0]
+        return csrf_input and csrf_input == xsrf_token
 
     def initialize(self, portal=None, disclaimer_banner=None):
-        self.putChild('assets', File(self._static_folder))
-        self.putChild('keys', KeysResource(self._services_factory))
-        self.putChild(AttachmentsResource.BASE_URL, AttachmentsResource(self._services_factory))
-        self.putChild('contacts', ContactsResource(self._services_factory))
-        self.putChild('features', FeaturesResource(portal))
-        self.putChild('tags', TagsResource(self._services_factory))
-        self.putChild('mails', MailsResource(self._services_factory))
-        self.putChild('mail', MailResource(self._services_factory))
-        self.putChild('feedback', FeedbackResource(self._services_factory))
-        self.putChild('user-settings', UserSettingsResource(self._services_factory))
-        self.putChild(LoginResource.BASE_URL, LoginResource(self._services_factory, portal, disclaimer_banner=disclaimer_banner))
-        self.putChild(LogoutResource.BASE_URL, LogoutResource(self._services_factory))
+        self.child_resources.add('assets', File(self._static_folder))
+        self.child_resources.add('keys', KeysResource(self._services_factory))
+        self.child_resources.add(AttachmentsResource.BASE_URL, AttachmentsResource(self._services_factory))
+        self.child_resources.add('contacts', ContactsResource(self._services_factory))
+        self.child_resources.add('features', FeaturesResource(portal))
+        self.child_resources.add('tags', TagsResource(self._services_factory))
+        self.child_resources.add('mails', MailsResource(self._services_factory))
+        self.child_resources.add('mail', MailResource(self._services_factory))
+        self.child_resources.add('feedback', FeedbackResource(self._services_factory))
+        self.child_resources.add('user-settings', UserSettingsResource(self._services_factory))
+        self.child_resources.add(LoginResource.BASE_URL,
+                                 LoginResource(self._services_factory, portal, disclaimer_banner=disclaimer_banner))
+        self.child_resources.add(LogoutResource.BASE_URL, LogoutResource(self._services_factory))
 
         self._mode = MODE_RUNNING
 
@@ -89,10 +108,26 @@ class RootResource(BaseResource):
     def _is_starting(self):
         return self._mode == MODE_STARTUP
 
+    def _add_csrf_cookie(self, request):
+        csrf_token = hashlib.sha256(os.urandom(CSRF_TOKEN_LENGTH)).hexdigest()
+        request.addCookie('XSRF-TOKEN', csrf_token)
+
     def render_GET(self, request):
+        self._add_csrf_cookie(request)
         if self._is_starting():
             return open(os.path.join(self._startup_assets_folder, 'Interstitial.html')).read()
         else:
             account_email = self.mail_service(request).account_email
             response = Template(self._html_template).safe_substitute(account_email=account_email)
             return str(response)
+
+
+class ChildResourcesMap(object):
+    def __init__(self):
+        self._registry = {}
+
+    def add(self, path, resource):
+        self._registry[path] = resource
+
+    def get(self, path):
+        return self._registry.get(path)
diff --git a/service/test/integration/test_retrieve_attachment.py b/service/test/integration/test_retrieve_attachment.py
index 4aaeadc2..31c8c5df 100644
--- a/service/test/integration/test_retrieve_attachment.py
+++ b/service/test/integration/test_retrieve_attachment.py
@@ -43,6 +43,23 @@ class RetrieveAttachmentTest(SoledadTestBase):
         self.assertEquals(expected_content_disposition, req.outgoingHeaders['content-disposition'])
         self.assertEquals(expected_content_type, req.outgoingHeaders['content-type'])
 
+    @defer.inlineCallbacks
+    def test_should_retrieve_attachment_even_if_xsrf_token_not_passed(self):
+        attachment_id, input_mail = self._create_mail_with_attachment()
+        yield self.mail_store.add_mail('INBOX', input_mail.as_string())
+
+        requested_filename = "file name with space"
+        expected_content_type = 'text/plain'
+        expected_content_disposition = 'attachment; filename="file name with space"'
+
+        attachment, req = yield self.get_attachment(attachment_id, 'base64', filename=requested_filename,
+                                                    content_type=expected_content_type, ajax=False, csrf='mismatched token')
+
+        self.assertEqual(200, req.code)
+        self.assertEquals('pretend to be binary attachment data', attachment)
+        self.assertEquals(expected_content_disposition, req.outgoingHeaders['content-disposition'])
+        self.assertEquals(expected_content_type, req.outgoingHeaders['content-type'])
+
     def _create_mail_with_attachment(self):
         input_mail = MIMEMultipart()
         input_mail.attach(MIMEText(u'a utf8 message', _charset='utf-8'))
diff --git a/service/test/support/integration/app_test_client.py b/service/test/support/integration/app_test_client.py
index 8ab58397..a2360a4e 100644
--- a/service/test/support/integration/app_test_client.py
+++ b/service/test/support/integration/app_test_client.py
@@ -244,22 +244,22 @@ class AppTestClient(object):
         time.sleep(1)
         return lambda: process.terminate()
 
-    def get(self, path, get_args='', as_json=True):
-        request = request_mock(path)
+    def get(self, path, get_args='', as_json=True, ajax=True, csrf='token'):
+        request = request_mock(path, ajax=ajax, csrf=csrf)
         request.args = get_args
         return self._render(request, as_json)
 
-    def post(self, path, body='', headers=None):
+    def post(self, path, body='', headers=None, ajax=True, csrf='token'):
         headers = headers or {'Content-Type': 'application/json'}
-        request = request_mock(path=path, method="POST", body=body, headers=headers)
+        request = request_mock(path=path, method="POST", body=body, headers=headers, ajax=ajax, csrf=csrf)
         return self._render(request)
 
-    def put(self, path, body):
-        request = request_mock(path=path, method="PUT", body=body, headers={'Content-Type': ['application/json']})
+    def put(self, path, body, ajax=True, csrf='token'):
+        request = request_mock(path=path, method="PUT", body=body, headers={'Content-Type': ['application/json']}, ajax=ajax, csrf=csrf)
         return self._render(request)
 
-    def delete(self, path, body=""):
-        request = request_mock(path=path, body=body, headers={'Content-Type': ['application/json']}, method="DELETE")
+    def delete(self, path, body="", ajax=True, csrf='token'):
+        request = request_mock(path=path, body=body, headers={'Content-Type': ['application/json']}, method="DELETE", ajax=ajax, csrf=csrf)
         return self._render(request)
 
     @defer.inlineCallbacks
@@ -322,13 +322,13 @@ class AppTestClient(object):
         defer.returnValue(mails)
 
     @defer.inlineCallbacks
-    def get_attachment(self, ident, encoding, filename=None, content_type=None):
+    def get_attachment(self, ident, encoding, filename=None, content_type=None, ajax=True, csrf='token'):
         params = {'encoding': [encoding]}
         if filename:
             params['filename'] = [filename]
         if content_type:
             params['content_type'] = [content_type]
-        deferred_result, req = self.get("/attachment/%s" % ident, params, as_json=False)
+        deferred_result, req = self.get("/attachment/%s" % ident, params, as_json=False, ajax=ajax, csrf=csrf)
         res = yield deferred_result
         defer.returnValue((res, req))
 
diff --git a/service/test/support/test_helper.py b/service/test/support/test_helper.py
index 77c74407..640baf6f 100644
--- a/service/test/support/test_helper.py
+++ b/service/test/support/test_helper.py
@@ -88,6 +88,7 @@ class PixRequestMock(DummyRequest):
         DummyRequest.__init__(self, path)
         self.content = None
         self.code = None
+        self.cookies = {}
 
     def getWrittenData(self):
         if len(self.written):
@@ -97,8 +98,14 @@ class PixRequestMock(DummyRequest):
         self.setResponseCode(302)
         self.setHeader(b"location", url)
 
+    def addCookie(self, key, value):
+        self.cookies[key] = value
 
-def request_mock(path='', method='GET', body='', headers={}):
+    def getCookie(self, key):
+        return self.cookies.get(key)
+
+
+def request_mock(path='', method='GET', body='', headers={}, ajax=True, csrf='token'):
     dummy = PixRequestMock(path.split('/'))
     for name, val in headers.iteritems():
         dummy.headers[name.lower()] = val
@@ -108,5 +115,9 @@ def request_mock(path='', method='GET', body='', headers={}):
     else:
         for key, val in body.items():
             dummy.addArg(key, val)
+    if ajax:
+        dummy.headers['x-requested-with'] = 'XMLHttpRequest'
+        dummy.headers['x-xsrf-token'] = csrf
+        dummy.addCookie('XSRF-TOKEN', csrf)
 
     return dummy
diff --git a/service/test/unit/resources/test_root_resource.py b/service/test/unit/resources/test_root_resource.py
index 3b0846ee..53481f56 100644
--- a/service/test/unit/resources/test_root_resource.py
+++ b/service/test/unit/resources/test_root_resource.py
@@ -1,11 +1,13 @@
 import unittest
 import re
+
+from mock import MagicMock, patch
 from mockito import mock, when, any as ANY
 
 from pixelated.application import UserAgentMode
 from test.unit.resources import DummySite
 from twisted.web.test.requesthelper import DummyRequest
-from pixelated.resources.root_resource import RootResource
+from pixelated.resources.root_resource import RootResource, MODE_STARTUP, MODE_RUNNING
 
 
 class TestRootResource(unittest.TestCase):
@@ -25,9 +27,11 @@ class TestRootResource(unittest.TestCase):
         root_resource._html_template = "<html><head><title>$account_email</title></head></html>"
         root_resource._mode = root_resource
         self.web = DummySite(root_resource)
+        self.root_resource = root_resource
 
     def test_render_GET_should_template_account_email(self):
         request = DummyRequest([''])
+        request.addCookie = lambda key, value: 'stubbed'
 
         d = self.web.get(request)
 
@@ -38,3 +42,79 @@ class TestRootResource(unittest.TestCase):
 
         d.addCallback(assert_response)
         return d
+
+    def _test_should_renew_xsrf_cookie(self):
+        request = DummyRequest([''])
+        request.addCookie = MagicMock()
+        generated_csrf_token = 'csrf_token'
+        mock_sha = MagicMock()
+        mock_sha.hexdigest = MagicMock(return_value=generated_csrf_token)
+
+        with patch('hashlib.sha256', return_value=mock_sha):
+            d = self.web.get(request)
+
+        def assert_csrf_cookie(_):
+            request.addCookie.assert_called_once_with('XSRF-TOKEN', generated_csrf_token)
+
+        d.addCallback(assert_csrf_cookie)
+        return d
+
+    def test_should_renew_xsrf_cookie_on_startup_mode(self):
+        self.root_resource._mode = MODE_STARTUP
+        self._test_should_renew_xsrf_cookie()
+
+    def test_should_renew_xsrf_cookie_on_running_mode(self):
+        self.root_resource._mode = MODE_RUNNING
+        self._test_should_renew_xsrf_cookie()
+
+    def _mock_ajax_csrf(self, request, csrf_token):
+        request.headers['x-requested-with'] = 'XMLHttpRequest'
+        request.headers['x-xsrf-token'] = csrf_token
+
+    def test_should_unauthorize_child_resource_ajax_requests_when_csrf_mismatch(self):
+        request = DummyRequest(['/child'])
+        self._mock_ajax_csrf(request, 'stubbed csrf token')
+
+        request.getCookie = MagicMock(return_value='mismatched csrf token')
+
+        d = self.web.get(request)
+
+        def assert_unauthorized(_):
+            self.assertEqual(401, request.responseCode)
+            self.assertEqual("Unauthorized!", request.written[0])
+
+        d.addCallback(assert_unauthorized)
+        return d
+
+    def test_should_authorize_child_resource_non_ajax_GET_requests(self):
+        request = DummyRequest(['features'])
+
+        request.getCookie = MagicMock(return_value='irrelevant -- stubbed')
+        self.root_resource.initialize()
+
+        d = self.web.get(request)
+
+        def assert_unauthorized(_):
+            self.assertEqual(200, request.code)
+
+        d.addCallback(assert_unauthorized)
+        return d
+
+    def test_should_unauthorize_child_resource_non_ajax_POST_requests_when_csrf_input_mismatch(self):
+        request = DummyRequest(['mails'])
+        request.method = 'POST'
+        request.addArg('csrftoken', 'some csrf token')
+        mock_content = MagicMock()
+        mock_content.read = MagicMock(return_value={})
+        request.content = mock_content
+
+        request.getCookie = MagicMock(return_value='mismatched csrf token')
+
+        d = self.web.get(request)
+
+        def assert_unauthorized(_):
+            self.assertEqual(401, request.responseCode)
+            self.assertEqual("Unauthorized!", request.written[0])
+
+        d.addCallback(assert_unauthorized)
+        return d
diff --git a/web-ui/app/js/helpers/browser.js b/web-ui/app/js/helpers/browser.js
index e5be6667..23aa79c8 100644
--- a/web-ui/app/js/helpers/browser.js
+++ b/web-ui/app/js/helpers/browser.js
@@ -23,7 +23,14 @@ define([], function () {
     window.location.replace(url);
   }
 
+  function getCookie(name) {
+    var value = '; ' + document.cookie;
+    var parts = value.split('; ' + name + '=');
+    if (parts.length === 2) return parts.pop().split(';').shift();
+  }
+
   return {
-    redirect: redirect
+    redirect: redirect,
+    getCookie: getCookie
   };
 });
diff --git a/web-ui/app/js/helpers/monitored_ajax.js b/web-ui/app/js/helpers/monitored_ajax.js
index 1cb720de..dc182d58 100644
--- a/web-ui/app/js/helpers/monitored_ajax.js
+++ b/web-ui/app/js/helpers/monitored_ajax.js
@@ -36,6 +36,8 @@ define(['page/events', 'views/i18n', 'helpers/browser'], function (events, i18n,
       }
     };
 
+    config.headers = {'X-XSRF-TOKEN': browser.getCookie('XSRF-TOKEN')};
+
     var originalComplete = config.complete;
     config.complete = function () {
       if (originalComplete) {
@@ -46,15 +48,15 @@ define(['page/events', 'views/i18n', 'helpers/browser'], function (events, i18n,
     return $.ajax(url, config).fail(function (xmlhttprequest, textstatus, message) {
       if (!config.skipErrorMessage) {
         var msg = (xmlhttprequest.responseJSON && xmlhttprequest.responseJSON.message) ||
-            messages[textstatus] ||
-            'unexpected problem while talking to server';
-        on.trigger(document, events.ui.userAlerts.displayMessage, {message: i18n(msg)});
+          messages[textstatus] ||
+          'unexpected problem while talking to server';
+        on.trigger(document, events.ui.userAlerts.displayMessage, {message: i18n(msg), class: 'error'});
       }
 
       if (xmlhttprequest.status === 302) {
         var redirectUrl = xmlhttprequest.getResponseHeader('Location');
         browser.redirect(redirectUrl);
-      }else if (xmlhttprequest.status === 401) {
+      } else if (xmlhttprequest.status === 401) {
         browser.redirect('/');
       }
 
diff --git a/web-ui/app/js/services/mail_service.js b/web-ui/app/js/services/mail_service.js
index a63d517e..412451cb 100644
--- a/web-ui/app/js/services/mail_service.js
+++ b/web-ui/app/js/services/mail_service.js
@@ -246,7 +246,7 @@ define(
             this.trigger(document, events.mails.available, _.merge({tag: this.attr.currentTag, forSearch: this.attr.lastQuery }, this.parseMails(data)));
           }.bind(this))
           .fail(function () {
-            this.trigger(document, events.ui.userAlerts.displayMessage, { message: i18n('Could not fetch messages') });
+            this.trigger(document, events.ui.userAlerts.displayMessage, { message: i18n('Could not fetch messages'), class: 'error' });
           }.bind(this));
       };
 
diff --git a/web-ui/test/spec/helpers/browser.spec.js b/web-ui/test/spec/helpers/browser.spec.js
new file mode 100644
index 00000000..5b740da8
--- /dev/null
+++ b/web-ui/test/spec/helpers/browser.spec.js
@@ -0,0 +1,12 @@
+define(['helpers/browser'], function (browser) {
+  'use strict';
+
+    describe('browser ', function() {
+      it('gets cookie', function() {
+        document.cookie = 'TWISTED_SESSION=ff895ffc45a4ce140bfc5dda6c61d232; i18next=en-us';
+        expect(browser.getCookie('TWISTED_SESSION')).toEqual('ff895ffc45a4ce140bfc5dda6c61d232');
+        expect(browser.getCookie('i18next')).toEqual('en-us');
+      });
+
+    });
+});
diff --git a/web-ui/test/spec/helpers/monitored_ajax_call.spec.js b/web-ui/test/spec/helpers/monitored_ajax_call.spec.js
index 972ca3ae..c0d55198 100644
--- a/web-ui/test/spec/helpers/monitored_ajax_call.spec.js
+++ b/web-ui/test/spec/helpers/monitored_ajax_call.spec.js
@@ -1,6 +1,24 @@
 define(['helpers/monitored_ajax'], function (monitoredAjax) {
   'use strict';
   describe('monitoredAjaxCall', function () {
+
+    describe('default configs', function () {
+
+     it('should always attach the xsrf token in the header', function () {
+       var component = { trigger: function () {}};
+       var d = $.Deferred();
+       spyOn($, 'ajax').and.returnValue(d);
+       document.cookie = 'XSRF-TOKEN=ff895ffc45a4ce140bfc5dda6c61d232; i18next=en-us';
+       var anyUrl = '/';
+
+       monitoredAjax(component, anyUrl, {});
+
+       expect($.ajax.calls.mostRecent().args[1].headers).toEqual({ 'X-XSRF-TOKEN' : 'ff895ffc45a4ce140bfc5dda6c61d232' });
+
+     });
+
+     });
+
     describe('when dealing with errors', function () {
 
       _.each(
@@ -19,7 +37,7 @@ define(['helpers/monitored_ajax'], function (monitoredAjax) {
           d.reject({ responseJSON: {}}, errorType, '');
 
           expect(component.trigger).toHaveBeenCalledWith(document, Pixelated.events.ui.userAlerts.displayMessage,
-              { message: errorMessage });
+              { message: errorMessage, class: 'error' });
         });
       });
 
@@ -33,7 +51,7 @@ define(['helpers/monitored_ajax'], function (monitoredAjax) {
         d.reject({ responseJSON: { message: 'Server Message'}}, 'error', '');
 
         expect(component.trigger).toHaveBeenCalledWith(document, Pixelated.events.ui.userAlerts.displayMessage,
-            { message: 'Server Message' });
+            { message: 'Server Message', class: 'error' });
       });
     });
 
@@ -76,4 +94,4 @@ define(['helpers/monitored_ajax'], function (monitoredAjax) {
 
     });
   });
-});
\ No newline at end of file
+});