const EventEmitter = require('events'); const { hexToArray } = require('./utils'); class FileReceiver extends EventEmitter { constructor() { super(); } download() { return window.crypto.subtle .importKey( 'jwk', { kty: 'oct', k: location.hash.slice(1), alg: 'A128GCM', ext: true }, { name: 'AES-GCM' }, true, ['encrypt', 'decrypt'] ) .then(key => { return new Promise((resolve, reject) => { const xhr = new XMLHttpRequest(); xhr.onprogress = event => { if (event.lengthComputable && event.target.status !== 404) { this.emit('progress', [event.loaded, event.total]); } }; xhr.onload = function(event) { if (xhr.status === 404) { reject(new Error('notfound')); return; } const blob = new Blob([this.response]); const type = xhr.getResponseHeader('Content-Type'); const meta = JSON.parse(xhr.getResponseHeader('X-File-Metadata')); const fileReader = new FileReader(); fileReader.onload = function() { resolve([ { data: this.result, filename: meta.filename, type, iv: meta.id }, key ]); }; fileReader.readAsArrayBuffer(blob); }; xhr.open('get', '/assets' + location.pathname.slice(0, -1), true); xhr.responseType = 'blob'; xhr.send(); }); }) .then(([fdata, key]) => { this.emit('decrypting'); return Promise.all([ window.crypto.subtle .decrypt( { name: 'AES-GCM', iv: hexToArray(fdata.iv), tagLength: 128 }, key, fdata.data ) .then(decrypted => { return Promise.resolve(decrypted); }), { name: decodeURIComponent(fdata.filename), type: fdata.type } ]); }); } } module.exports = FileReceiver;