1 files changed, 87 insertions, 0 deletions

diff --git a/packages/main/src/infrastructure/electron/impl/hardenSession.ts b/packages/main/src/infrastructure/electron/impl/hardenSession.ts
new file mode 100644
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--- /dev/null
+++ b/packages/main/src/infrastructure/electron/impl/hardenSession.ts
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C)  2022 Kristóf Marussy <kristof@marussy.com>
+ *
+ * This file is part of Sophie.
+ *
+ * Sophie is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { URL } from 'node:url';
+
+import type { Session } from 'electron';
+
+import { getLogger } from '../../../utils/log';
+import type Resources from '../../resources/Resources';
+
+import { DEVMODE_ALLOWED_URL_PREFIXES } from './devTools';
+
+const log = getLogger('hardenSession');
+
+/**
+ * Hardens a session to prevent loading resources outside the renderer resources and
+ * to reject all permission requests.
+ *
+ * In dev mode, installation of extensions and opening the devtools will be allowed.
+ *
+ * @param resources The resource handle associated with the paths and URL of the application.
+ * @param devMode Whether the application is in development mode.
+ * @param session The session to harden.
+ */
+export default function hardenSession(
+  resources: Resources,
+  devMode: boolean,
+  session: Session,
+): void {
+  session.setPermissionRequestHandler((_webContents, _permission, callback) => {
+    callback(false);
+  });
+
+  const rendererBaseURL = resources.getRendererURL('/');
+  log.debug('Renderer base URL:', rendererBaseURL);
+
+  const webSocketBaseURL = rendererBaseURL.replace(/^http(s)?:/, 'ws$1:');
+  log.debug('WebSocket base URL:', webSocketBaseURL);
+
+  function shouldCancelRequest(url: string, method: string): boolean {
+    if (method !== 'GET') {
+      return true;
+    }
+    let normalizedURL: string;
+    try {
+      normalizedURL = new URL(url).toString();
+    } catch {
+      return true;
+    }
+    if (
+      devMode &&
+      DEVMODE_ALLOWED_URL_PREFIXES.some((prefix) =>
+        normalizedURL.startsWith(prefix),
+      )
+    ) {
+      return false;
+    }
+    const isHttp = normalizedURL.startsWith(rendererBaseURL);
+    const isWs = normalizedURL.startsWith(webSocketBaseURL);
+    return !isHttp && !isWs;
+  }
+
+  session.webRequest.onBeforeRequest(({ url, method }, callback) => {
+    const cancel = shouldCancelRequest(url, method);
+    if (cancel) {
+      log.error('Prevented loading', method, url);
+    }
+    callback({ cancel });
+  });
+}