From d365dd33f36400b08516fe12ec766fa53b05ef3b Mon Sep 17 00:00:00 2001
From: ivandobskygithub <github@dobsky.com>
Date: Wed, 6 May 2026 09:10:53 +0100
Subject: [PATCH] Add Content-Security-Policy header; tighten unwatch-file
 guard
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

CSP: default-src 'self' with allowances for xterm's runtime inline styles
(style-src 'unsafe-inline'), data: imgs, and data: fonts. No 'unsafe-inline'
or 'unsafe-eval' for scripts — markdown is sanitised through DOMPurify
before hitting the DOM.

unwatch-file: route the path through assertPathAllowed so the IPC surface
is uniform with watch-file / read-file-for-panel / save-file-for-panel.
A renderer can only ever close a watcher it could have opened anyway, so
this is consistency rather than a real escalation fix.

Identified during a follow-up audit against upstream PR #27. The other
items in #27 (path-guard on file IPCs, DOMPurify on markdown, scheduler
shell-quoting) are already in place via earlier hardening commits.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 main.js | 32 +++++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/main.js b/main.js
index ebfa277..3d3c613 100644
--- a/main.js
+++ b/main.js
@@ -451,11 +451,12 @@ ipcMain.handle('watch-file', (_event, filePath) => {
 });
 
 ipcMain.handle('unwatch-file', (_event, filePath) => {
-  const resolved = path.resolve(filePath);
-  const watcher = fileWatchers.get(resolved);
+  const check = assertPathAllowed(filePath, 'read');
+  if (!check.ok) return { ok: false, error: check.error };
+  const watcher = fileWatchers.get(check.resolved);
   if (watcher) {
     watcher.close();
-    fileWatchers.delete(resolved);
+    fileWatchers.delete(check.resolved);
   }
   return { ok: true };
 });
@@ -1417,6 +1418,31 @@ ipcMain.handle('updater-install', () => {});
 
 // --- App lifecycle ---
 app.whenReady().then(() => {
+  // Content-Security-Policy: lock the renderer to same-origin script/style
+  // execution. xterm/codemirror are bundled locally; markdown is rendered
+  // through DOMPurify before reaching the DOM, so 'unsafe-inline' is not
+  // required for scripts. Inline styles are still allowed (xterm injects
+  // colour styles at runtime via setAttribute('style', …)).
+  const { session } = require('electron');
+  session.defaultSession.webRequest.onHeadersReceived((details, callback) => {
+    callback({
+      responseHeaders: {
+        ...details.responseHeaders,
+        'Content-Security-Policy': [
+          "default-src 'self'; " +
+          "script-src 'self'; " +
+          "style-src 'self' 'unsafe-inline'; " +
+          "img-src 'self' data: blob:; " +
+          "font-src 'self' data:; " +
+          "connect-src 'self'; " +
+          "object-src 'none'; " +
+          "base-uri 'self'; " +
+          "frame-ancestors 'none'"
+        ],
+      },
+    });
+  });
+
   // Seed path-guard allowed roots from every known Claude projects folder
   // so the file panel can read project files immediately at startup.
   try {