import assets from '../common/assets'; import { version } from '../package.json'; import Keychain from './keychain'; import { downloadStream } from './api'; import { transformStream } from './streams'; import Zip from './zip'; import contentDisposition from 'content-disposition'; let noSave = false; const map = new Map(); const IMAGES = /.*\.(png|svg|jpg)$/; const VERSIONED_ASSET = /\.[A-Fa-f0-9]{8}\.(js|css|png|svg|jpg)$/; const DOWNLOAD_URL = /\/api\/download\/([A-Fa-f0-9]{4,})/; self.addEventListener('install', event => { event.waitUntil(precache()); }); self.addEventListener('activate', event => { event.waitUntil(self.clients.claim().then(cleanCache)); }); async function decryptStream(id) { const file = map.get(id); if (!file) { return new Response(null, { status: 400 }); } try { let size = file.size; let type = file.type; const keychain = new Keychain(file.key, file.nonce); if (file.requiresPassword) { keychain.setPassword(file.password, file.url); } file.download = downloadStream(id, keychain); const body = await file.download.result; const decrypted = keychain.decryptStream(body); let zipStream = null; if (file.type === 'send-archive') { const zip = new Zip(file.manifest, decrypted); zipStream = zip.stream; type = 'application/zip'; size = zip.size; } const responseStream = transformStream( zipStream || decrypted, { transform(chunk, controller) { file.progress += chunk.length; controller.enqueue(chunk); } }, function oncancel() { // NOTE: cancel doesn't currently fire on chrome // https://bugs.chromium.org/p/chromium/issues/detail?id=638494 file.download.cancel(); map.delete(id); } ); const headers = { 'Content-Disposition': contentDisposition(file.filename), 'Content-Type': type, 'Content-Length': size }; return new Response(responseStream, { headers }); } catch (e) { if (noSave) { return new Response(null, { status: e.message }); } return new Response(null, { status: 302, headers: { Location: `/download/${id}/#${file.key}` } }); } } async function precache() { const cache = await caches.open(version); const images = assets.match(IMAGES); await cache.addAll(images); return self.skipWaiting(); } async function cleanCache() { const oldCaches = await caches.keys(); for (const c of oldCaches) { if (c !== version) { await caches.delete(c); } } } async function cachedOrFetched(req) { const cache = await caches.open(version); const cached = await cache.match(req); if (cached) { return cached; } const fetched = await fetch(req); if (fetched.ok && VERSIONED_ASSET.test(req.url)) { cache.put(req, fetched.clone()); } return fetched; } self.onfetch = event => { const req = event.request; if (req.method !== 'GET') return; const url = new URL(req.url); const dlmatch = DOWNLOAD_URL.exec(url.pathname); if (dlmatch) { event.respondWith(decryptStream(dlmatch[1])); } else if (VERSIONED_ASSET.test(url.pathname)) { event.respondWith(cachedOrFetched(req)); } }; self.onmessage = event => { if (event.data.request === 'init') { noSave = event.data.noSave; const info = { key: event.data.key, nonce: event.data.nonce, filename: event.data.filename, requiresPassword: event.data.requiresPassword, password: event.data.password, url: event.data.url, type: event.data.type, manifest: event.data.manifest, size: event.data.size, progress: 0 }; map.set(event.data.id, info); event.ports[0].postMessage('file info received'); } else if (event.data.request === 'progress') { const file = map.get(event.data.id); if (!file) { event.ports[0].postMessage({ error: 'cancelled' }); } else { if (file.progress === file.size) { map.delete(event.data.id); } event.ports[0].postMessage({ progress: file.progress }); } } else if (event.data.request === 'cancel') { const file = map.get(event.data.id); if (file) { if (file.download) { file.download.cancel(); } map.delete(event.data.id); } event.ports[0].postMessage('download cancelled'); } };