From eb1606c9c2ac7d37f0f54d11473cc37acb34c06a Mon Sep 17 00:00:00 2001
From: Felix Ableitner <me@nutomic.com>
Date: Tue, 5 Apr 2022 14:43:56 +0200
Subject: [PATCH] Set content security policy http header for all responses

---
 src/server/index.tsx | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/src/server/index.tsx b/src/server/index.tsx
index d8eb8075..9756b3fa 100644
--- a/src/server/index.tsx
+++ b/src/server/index.tsx
@@ -27,6 +27,13 @@ const [hostname, port] = process.env["LEMMY_UI_HOST"]
 const extraThemesFolder =
   process.env["LEMMY_UI_EXTRA_THEMES_FOLDER"] || "./extra_themes";
 
+server.use(function (_req, res, next) {
+  res.setHeader(
+    "Content-Security-Policy",
+    "default-src 'none'; connect-src 'self'; img-src * data:; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; form-action 'self'; base-uri 'self'"
+  );
+  next();
+});
 server.use(express.json());
 server.use(express.urlencoded({ extended: false }));
 server.use("/static", express.static(path.resolve("./dist")));
@@ -166,13 +173,6 @@ server.get("/*", async (req, res) => {
       return res.redirect(context.url);
     }
 
-    const cspHtml = (
-      <meta
-        http-equiv="Content-Security-Policy"
-        content="default-src data: 'self'; connect-src * ws: wss:; frame-src *; img-src * data:; script-src 'self'; style-src 'self' 'unsafe-inline'; manifest-src 'self'"
-      />
-    );
-
     const eruda = (
       <>
         <script src="//cdn.jsdelivr.net/npm/eruda"></script>
@@ -180,12 +180,8 @@ server.get("/*", async (req, res) => {
       </>
     );
     const erudaStr = process.env["LEMMY_UI_DEBUG"] ? renderToString(eruda) : "";
-
     const root = renderToString(wrapper);
     const symbols = renderToString(SYMBOLS);
-    const cspStr = process.env.LEMMY_EXTERNAL_HOST
-      ? renderToString(cspHtml)
-      : "";
     const helmet = Helmet.renderStatic();
 
     const config: ILemmyConfig = { wsHost: process.env.LEMMY_WS_HOST };
@@ -208,9 +204,6 @@ server.get("/*", async (req, res) => {
            <meta charset="utf-8">
            <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
 
-           <!-- Content Security Policy -->
-           ${cspStr}
-
            <!-- Web app manifest -->
            <link rel="manifest" href="/static/assets/manifest.webmanifest">