Take the file path from webUtils.getPathForFile instead of `File.pa…

…th` (#46971)

web/packages/teleterm/src/preload.ts

@@ -16,7 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-import { contextBridge } from 'electron';
+import { contextBridge, webUtils } from 'electron';
 import { ChannelCredentials, ServerCredentials } from '@grpc/grpc-js';
 import { GrpcTransport } from '@protobuf-ts/grpc-transport';
 
@@ -99,6 +99,14 @@ async function getElectronGlobals(): Promise<ElectronGlobals> {
     vnetClient,
     ptyServiceClient,
     setupTshdEventContextBridgeService,
+    // Ideally, we would call this function only on the preload side,
+    // but there's no easy way to access the file there (constructing the tshd
+    // call for a file transfer happens entirely on the renderer side).
+    //
+    // However, the risk of exposing this API is minimal because the file passed
+    // in cannot be constructed in JS (it must be selected in the file picker).
+    // So an attacker cannot pass a fake file to probe the file system.
+    getPathForFile: file => webUtils.getPathForFile(file),
   };
 }
 

web/packages/teleterm/src/types.ts

@@ -111,4 +111,6 @@ export type ElectronGlobals = {
   readonly setupTshdEventContextBridgeService: (
     listener: TshdEventContextBridgeService
   ) => void;
+  /** Exposes Electron's webUtils.getPathForFile. */
+  getPathForFile(file: File): string;
 };

web/packages/teleterm/src/ui/DocumentTerminal/DocumentTerminal.tsx

@@ -96,7 +96,7 @@ export function DocumentTerminal(props: {
                 {
                   serverUri: doc.serverUri,
                   login: doc.login,
-                  source: file.path,
+                  source: ctx.getPathForFile(file),
                   destination: destinationPath,
                 },
                 abortController

web/packages/teleterm/src/ui/appContext.ts

@@ -75,6 +75,7 @@ export default class AppContext implements IAppContext {
   setupTshdEventContextBridgeService: (
     service: TshdEventContextBridgeService
   ) => void;
+  getPathForFile: (file: File) => string;
   reloginService: ReloginService;
   tshdNotificationsService: TshdNotificationsService;
   headlessAuthenticationService: HeadlessAuthenticationService;
@@ -96,6 +97,7 @@ export default class AppContext implements IAppContext {
     this.mainProcessClient = mainProcessClient;
     this.notificationsService = new NotificationsService();
     this.configService = this.mainProcessClient.configService;
+    this.getPathForFile = config.getPathForFile;
     this.usageService = new UsageService(
       tshClient,
       this.configService,

web/packages/teleterm/src/ui/fixtures/mocks.ts

@@ -38,6 +38,7 @@ export class MockAppContext extends AppContext {
       vnetClient,
       ptyServiceClient,
       setupTshdEventContextBridgeService: () => {},
+      getPathForFile: () => '',
     });
   }
 }

web/packages/teleterm/src/ui/types.ts

@@ -64,7 +64,8 @@ export interface IAppContext {
   headlessAuthenticationService: HeadlessAuthenticationService;
   tshd: TshdClient;
   vnet: VnetClient;
-
+  /** Exposes Electron's webUtils.getPathForFile. */
+  getPathForFile: (file: File) => string;
   pullInitialState(): Promise<void>;
 
   /**