Merge pull request #3820 from overleaf/as-block-ie

Add middleware to block unsupported browsers

GitOrigin-RevId: b1f1e4ae1572c3c323dc72442c8d5169b4879d5d

services/web/app/src/infrastructure/UnsupportedBrowserMiddleware.js

@@ -0,0 +1,23 @@
+const Bowser = require('bowser')
+const Settings = require('settings-sharelatex')
+
+function unsupportedBrowserMiddleware(req, res, next) {
+  if (!Settings.unsupportedBrowsers) return next()
+
+  const userAgent = req.headers['user-agent']
+
+  const parser = Bowser.getParser(userAgent)
+
+  // Allow bots through by only ignoring bots or unrecognised UA strings
+  const isBot = parser.isPlatform('bot') || !parser.getBrowserName()
+  if (isBot) return next()
+
+  const isUnsupported = parser.satisfies(Settings.unsupportedBrowsers)
+  if (isUnsupported) {
+    return res.redirect('/unsupported-browser')
+  }
+
+  next()
+}
+
+module.exports = { unsupportedBrowserMiddleware }

services/web/app/src/router.js

@@ -49,6 +49,9 @@ const InstitutionsController = require('./Features/Institutions/InstitutionsCont
 const UserMembershipRouter = require('./Features/UserMembership/UserMembershipRouter')
 const SystemMessageController = require('./Features/SystemMessages/SystemMessageController')
 const { Joi, validate } = require('./infrastructure/Validation')
+const {
+  unsupportedBrowserMiddleware
+} = require('./infrastructure/UnsupportedBrowserMiddleware')
 
 const logger = require('logger-sharelatex')
 const _ = require('underscore')
@@ -263,6 +266,7 @@ function initialize(webRouter, privateApiRouter, publicApiRouter) {
       maxRequests: 30,
       timeInterval: 60
     }),
+    unsupportedBrowserMiddleware,
     ProjectController.projectListPage
   )
   webRouter.post(
@@ -284,6 +288,7 @@ function initialize(webRouter, privateApiRouter, publicApiRouter) {
       maxRequests: 15,
       timeInterval: 60
     }),
+    unsupportedBrowserMiddleware,
     AuthenticationController.validateUserSession(),
     AuthorizationMiddleware.ensureUserCanReadProject,
     ProjectController.loadEditor
@@ -1138,5 +1143,9 @@ function initialize(webRouter, privateApiRouter, publicApiRouter) {
     TokenAccessController.grantTokenAccessReadOnly
   )
 
+  webRouter.get('/unsupported-browser', (req, res) => {
+    res.render('general/unsupported-browser')
+  })
+
   webRouter.get('*', ErrorController.notFound)
 }

services/web/app/views/general/unsupported-browser.pug

@@ -0,0 +1,16 @@
+extends ../layout/layout-no-js
+
+block vars
+	- metadata = { title: 'Unsupported browser', viewport: true }
+
+block body
+	body.full-height
+		main.content.content-alt.full-height
+			.container.full-height
+				.error-container.full-height
+					.error-details
+						h1.error-status Unsupported Browser
+						p.error-description
+							| Sorry, we don't support your browser anymore. Find out more about #[a(href="https://www.overleaf.com/learn/how-to/What_browsers_do_you_support") what browsers we support].
+							br
+							| If you think you're seeing this message in error, please #[a(href="/contact") let us know].