element-desktop/src/media-auth.ts

81 lines
3.4 KiB
TypeScript

/*
Copyright 2024 New Vector Ltd
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
import { BrowserWindow, ipcMain, session } from "electron";
/**
* Check for feature support from the server.
* This requires asking the renderer process for supported versions.
*/
async function getSupportedVersions(window: BrowserWindow): Promise<string[]> {
return new Promise((resolve) => {
ipcMain.once("serverSupportedVersions", (_, versionsResponse) => {
resolve(versionsResponse?.versions || []);
});
window.webContents.send("serverSupportedVersions"); // ping now that the listener exists
});
}
/**
* Get the access token for the user.
* This requires asking the renderer process for the access token.
*/
async function getAccessToken(window: BrowserWindow): Promise<string | undefined> {
return new Promise((resolve) => {
ipcMain.once("userAccessToken", (_, accessToken) => {
resolve(accessToken);
});
window.webContents.send("userAccessToken"); // ping now that the listener exists
});
}
export function setupMediaAuth(window: BrowserWindow): void {
session.defaultSession.webRequest.onBeforeRequest(async (req, callback) => {
// This handler emulates the element-web service worker, where URLs are rewritten late in the request
// for backwards compatibility. As authenticated media becomes more prevalent, this should be replaced
// by the app using authenticated URLs from the outset.
let url = req.url;
if (!url.includes("/_matrix/media/v3/download") && !url.includes("/_matrix/media/v3/thumbnail")) {
return callback({}); // not a URL we care about
}
const supportedVersions = await getSupportedVersions(window);
// We have to check that the access token is truthy otherwise we'd be intercepting pre-login media request too,
// e.g. those required for SSO button icons.
const accessToken = await getAccessToken(window);
if (supportedVersions.includes("v1.11") && accessToken) {
url = url.replace(/\/media\/v3\/(.*)\//, "/client/v1/media/$1/");
return callback({ redirectURL: url });
} else {
return callback({}); // no support == no modification
}
});
session.defaultSession.webRequest.onBeforeSendHeaders(async (req, callback) => {
if (!req.url.includes("/_matrix/client/v1/media")) {
return callback({}); // invoke unmodified
}
// Only add authorization header to authenticated media URLs. This emulates the service worker
// behaviour in element-web.
const accessToken = await getAccessToken(window);
// `accessToken` can be falsy, but if we're trying to download media without authentication
// then we should expect failure anyway.
const headers = { ...req.requestHeaders, Authorization: `Bearer ${accessToken}` };
return callback({ requestHeaders: headers });
});
}