import Keychain from './keychain'; import { downloadStream } from './api'; import { transform } from './streams'; import contentDisposition from 'content-disposition'; let noSave = false; const map = new Map(); self.addEventListener('install', event => { self.skipWaiting(); }); self.addEventListener('activate', event => { self.clients.claim(); }); async function decryptStream(request) { const id = request.url.split('/')[5]; try { const file = map.get(id); const keychain = new Keychain(file.key, file.nonce); file.download = downloadStream(id, keychain); const body = await file.download.result; const readStream = transform(body, { transform: (chunk, controller) => { file.progress += chunk.length; controller.enqueue(chunk); } }); const decrypted = keychain.decryptStream(readStream); const headers = { 'Content-Disposition': contentDisposition(file.filename), 'Content-Type': file.type, 'Content-Length': file.size }; return new Response(decrypted, { headers }); } catch (e) { if (noSave) { return new Response(null, { status: e.message }); } const redirectRes = await fetch(`/download/${id}`); return new Response(redirectRes.body, { status: 302 }); } finally { // TODO: need to clean up, but not break progress // map.delete(id) } } self.onfetch = event => { const req = event.request.clone(); if (req.url.includes('/api/download')) { event.respondWith(decryptStream(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, type: event.data.type, size: event.data.size, progress: 0, cancelled: false }; if (event.data.requiresPassword) { info.password = event.data.password; info.url = event.data.url; } 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({ progress: 0 }); } else if (file.cancelled) { event.ports[0].postMessage({ error: 'cancelled' }); } else { event.ports[0].postMessage({ progress: file.progress }); } } else if (event.data.request === 'cancel') { const file = map.get(event.data.id); if (file) { file.cancelled = true; if (file.download) { file.download.cancel(); } } event.ports[0].postMessage('download cancelled'); } };