feat: support Jitsi instances that set x-frame-options and frame-ance…

…stors CSP (#798)

While in browser environments the headers are sensible, the only purpose
of the electron app is load jitsi in the iframe api. This also is how the mobile apps behave (they also ignore the framing headers)

Fixes: #285

README.md

@@ -37,20 +37,6 @@ For *macOS* user, you can install the application using the following command:
 brew install --cask jitsi-meet
 ```
 
-### Using it with your own Jitsi Meet installation
-
-:warning: The following additional HTTP headers are known to break the Electron App:
-
-```
-Content-Security-Policy "frame-ancestors [looks like any value is bad]";
-X-Frame-Options "DENY";
-X-Frame-Options "sameorigin";
-```
-A working Content Security Policy looks like that:
-```
-Content-Security-Policy "img-src 'self' 'unsafe-inline' data:; script-src 'self' 'unsafe-inline' 'wasm-eval'; style-src 'self' 'unsafe-inline'; font-src 'self'; object-src 'none'; base-uri 'self'; form-action 'none';";
-```
-
 ## Development
 
 If you want to hack on this project, here is how you do it.

main.js

@@ -228,6 +228,25 @@ function createJitsiMeetWindow() {
 
     mainWindow.webContents.setWindowOpenHandler(windowOpenHandler);
 
+    // Filter out x-frame-options and frame-ancestors CSP to allow loading jitsi via the iframe API
+    // Resolves https://github.com/jitsi/jitsi-meet-electron/issues/285
+    mainWindow.webContents.session.webRequest.onHeadersReceived((details, callback) => {
+        delete details.responseHeaders['x-frame-options'];
+
+        if (details.responseHeaders['content-security-policy']) {
+            const cspFiltered = details.responseHeaders['content-security-policy'][0]
+                .split(';')
+                .filter(x => x.indexOf('frame-ancestors') === -1)
+                .join(';');
+
+            details.responseHeaders['content-security-policy'] = [ cspFiltered ];
+        }
+
+        callback({
+            responseHeaders: details.responseHeaders
+        });
+    });
+
     initPopupsConfigurationMain(mainWindow);
     setupAlwaysOnTopMain(mainWindow, null, windowOpenHandler);
     setupPowerMonitorMain(mainWindow);