From 080436aebb4c4681f85cc8bf5d8563832ff8dbdd Mon Sep 17 00:00:00 2001
From: Literallie <git@l1t.li>
Date: Wed, 18 Oct 2017 17:48:53 +0200
Subject: [PATCH] CSP: Add nonce to slide view inline JS

---
 app.js                 | 7 +++++++
 lib/response.js        | 3 ++-
 package.json           | 1 +
 public/views/slide.ejs | 2 +-
 4 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/app.js b/app.js
index 8af029e..b78f94e 100644
--- a/app.js
+++ b/app.js
@@ -12,6 +12,7 @@ var session = require('express-session')
 var SequelizeStore = require('connect-session-sequelize')(session.Store)
 var fs = require('fs')
 var path = require('path')
+var uuid = require('uuid')
 
 var morgan = require('morgan')
 var passportSocketIo = require('passport.socketio')
@@ -108,6 +109,11 @@ if (config.hsts.enable) {
   logger.info('https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security')
 }
 
+app.use((req, res, next) => {
+  res.locals.nonce = uuid.v4()
+  next()
+})
+
 // use Content-Security-Policy to limit XSS, dangerous plugins, etc.
 // https://helmetjs.github.io/docs/csp/
 if (config.csp.enable) {
@@ -126,6 +132,7 @@ if (config.csp.enable) {
       directives[propertyName] = directive;
     }
   }
+  directives.scriptSrc.push(function (req, res) { return "'nonce-" + res.locals.nonce + "'" })
   if(config.csp.upgradeInsecureRequests === 'auto') {
     directives.upgradeInsecureRequests = config.usessl === 'true'
   } else {
diff --git a/lib/response.js b/lib/response.js
index a22d1e7..287d53e 100755
--- a/lib/response.js
+++ b/lib/response.js
@@ -584,7 +584,8 @@ function showPublishSlide (req, res, next) {
         lastchangeuserprofile: note.lastchangeuser ? models.User.getProfile(note.lastchangeuser) : null,
         robots: meta.robots || false, // default allow robots
         GA: meta.GA,
-        disqus: meta.disqus
+        disqus: meta.disqus,
+        cspNonce: res.locals.nonce
       }
       return renderPublishSlide(data, res)
     }).catch(function (err) {
diff --git a/package.json b/package.json
index 4c8dc56..35fe4f9 100644
--- a/package.json
+++ b/package.json
@@ -114,6 +114,7 @@
     "tedious": "^1.14.0",
     "to-markdown": "^3.0.3",
     "toobusy-js": "^0.5.1",
+    "uuid": "^3.1.0",
     "uws": "~0.14.1",
     "validator": "^6.2.0",
     "velocity-animate": "^1.4.0",
diff --git a/public/views/slide.ejs b/public/views/slide.ejs
index 7ff5016..c7dd989 100644
--- a/public/views/slide.ejs
+++ b/public/views/slide.ejs
@@ -41,7 +41,7 @@
         <link rel="stylesheet" href="<%- url %>/css/slide.css">
 
         <!-- Printing and PDF exports -->
-        <script>
+        <script nonce="<%= cspNonce %>">
             var link = document.createElement( 'link' );
             link.rel = 'stylesheet';
             link.type = 'text/css';