AFFiNE-Mirror/packages/frontend/apps/electron/src/main/protocol.ts

import { join } from 'node:path';

import { app, net, protocol, session } from 'electron';
import cookieParser from 'set-cookie-parser';

import { resourcesPath } from '../shared/utils';
import { anotherHost, mainHost } from './constants';
import { logger } from './logger';

protocol.registerSchemesAsPrivileged([
  {
    scheme: 'assets',
    privileges: {
      secure: false,
      corsEnabled: true,
      supportFetchAPI: true,
      standard: true,
      bypassCSP: true,
    },
  },
]);

protocol.registerSchemesAsPrivileged([
  {
    scheme: 'file',
    privileges: {
      secure: false,
      corsEnabled: true,
      supportFetchAPI: true,
      standard: true,
      bypassCSP: true,
      stream: true,
    },
  },
]);

const NETWORK_REQUESTS = ['/api', '/ws', '/socket.io', '/graphql'];
const webStaticDir = join(resourcesPath, 'web-static');

function isNetworkResource(pathname: string) {
  return NETWORK_REQUESTS.some(opt => pathname.startsWith(opt));
}

async function handleFileRequest(request: Request) {
  const urlObject = new URL(request.url);

  if (urlObject.host === anotherHost) {
    urlObject.host = mainHost;
  }

  const isAbsolutePath = urlObject.host !== '.';

  // Redirect to webpack dev server if defined
  if (process.env.DEV_SERVER_URL && !isAbsolutePath) {
    const devServerUrl = new URL(
      urlObject.pathname,
      process.env.DEV_SERVER_URL
    );
    return net.fetch(devServerUrl.toString(), request);
  }
  const clonedRequest = Object.assign(request.clone(), {
    bypassCustomProtocolHandlers: true,
  });
  // this will be file types (in the web-static folder)
  let filepath = '';

  // for relative path, load the file in resources
  if (!isAbsolutePath) {
    if (urlObject.pathname.split('/').at(-1)?.includes('.')) {
      // Sanitize pathname to prevent path traversal attacks
      const decodedPath = decodeURIComponent(urlObject.pathname);
      const normalizedPath = join(webStaticDir, decodedPath).normalize();
      if (!normalizedPath.startsWith(webStaticDir)) {
        // Attempted path traversal - reject by using empty path
        filepath = join(webStaticDir, '');
      } else {
        filepath = normalizedPath;
      }
    } else {
      // else, fallback to load the index.html instead
      filepath = join(webStaticDir, 'index.html');
    }
  } else {
    filepath = decodeURIComponent(urlObject.pathname);
    // security check if the filepath is within app.getPath('sessionData')
    const sessionDataPath = app.getPath('sessionData');
    const tempPath = app.getPath('temp');
    if (
      !filepath.startsWith(sessionDataPath) &&
      !filepath.startsWith(tempPath)
    ) {
      throw new Error('Invalid filepath');
    }
  }
  return net.fetch('file://' + filepath, clonedRequest);
}

export function registerProtocol() {
  protocol.handle('file', request => {
    return handleFileRequest(request);
  });

  protocol.handle('assets', request => {
    return handleFileRequest(request);
  });

  session.defaultSession.webRequest.onHeadersReceived(
    (responseDetails, callback) => {
      const { responseHeaders } = responseDetails;
      (async () => {
        if (responseHeaders) {
          const originalCookie =
            responseHeaders['set-cookie'] || responseHeaders['Set-Cookie'];

          if (originalCookie) {
            // save the cookies, to support third party cookies
            for (const cookies of originalCookie) {
              const parsedCookies = cookieParser.parse(cookies);
              for (const parsedCookie of parsedCookies) {
                if (!parsedCookie.value) {
                  await session.defaultSession.cookies.remove(
                    responseDetails.url,
                    parsedCookie.name
                  );
                } else {
                  await session.defaultSession.cookies.set({
                    url: responseDetails.url,
                    domain: parsedCookie.domain,
                    expirationDate: parsedCookie.expires?.getTime(),
                    httpOnly: parsedCookie.httpOnly,
                    secure: parsedCookie.secure,
                    value: parsedCookie.value,
                    name: parsedCookie.name,
                    path: parsedCookie.path,
                    sameSite: parsedCookie.sameSite?.toLowerCase() as
                      | 'unspecified'
                      | 'no_restriction'
                      | 'lax'
                      | 'strict'
                      | undefined,
                  });
                }
              }
            }
          }

          delete responseHeaders['access-control-allow-origin'];
          delete responseHeaders['access-control-allow-headers'];
          responseHeaders['Access-Control-Allow-Origin'] = ['*'];
          responseHeaders['Access-Control-Allow-Headers'] = ['*'];
        }
      })()
        .catch(err => {
          logger.error('error handling headers received', err);
        })
        .finally(() => {
          callback({ responseHeaders });
        });
    }
  );

  session.defaultSession.webRequest.onBeforeSendHeaders((details, callback) => {
    const url = new URL(details.url);
    const pathname = url.pathname;

    (async () => {
      // session cookies are set to file:// on production
      // if sending request to the cloud, attach the session cookie (to affine cloud server)
      if (
        url.protocol === 'http:' ||
        url.protocol === 'https:' ||
        url.protocol === 'ws:' ||
        url.protocol === 'wss:'
      ) {
        const cookies = await session.defaultSession.cookies.get({
          url: details.url,
        });

        const cookieString = cookies
          .map(c => `${c.name}=${c.value}`)
          .join('; ');
        delete details.requestHeaders['cookie'];
        details.requestHeaders['Cookie'] = cookieString;

        // mitigate the issue of the worker not being able to access the origin
        if (isNetworkResource(pathname)) {
          details.requestHeaders['origin'] = url.origin;
          details.requestHeaders['referer'] = url.origin;
        }
      }
    })()
      .catch(err => {
        logger.error('error handling before send headers', err);
      })
      .finally(() => {
        callback({
          cancel: false,
          requestHeaders: details.requestHeaders,
        });
      });
  });
}