81 lines
1.8 KiB
JavaScript
81 lines
1.8 KiB
JavaScript
import EventEmitter from 'events';
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import { hexToArray } from './utils';
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export default class FileReceiver extends EventEmitter {
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constructor(url, k) {
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super();
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this.key = window.crypto.subtle.importKey(
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'jwk',
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{
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k,
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kty: 'oct',
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alg: 'A128GCM',
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ext: true
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},
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{
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name: 'AES-GCM'
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},
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false,
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['decrypt']
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);
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this.url = url;
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}
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downloadFile() {
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return new Promise((resolve, reject) => {
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const xhr = new XMLHttpRequest();
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xhr.onprogress = event => {
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if (event.lengthComputable && event.target.status !== 404) {
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this.emit('progress', [event.loaded, event.total]);
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}
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};
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xhr.onload = function(event) {
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if (xhr.status === 404) {
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reject(new Error('notfound'));
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return;
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}
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const blob = new Blob([this.response]);
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const type = xhr.getResponseHeader('Content-Type');
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const meta = JSON.parse(xhr.getResponseHeader('X-File-Metadata'));
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const fileReader = new FileReader();
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fileReader.onload = function() {
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resolve({
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data: this.result,
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name: meta.filename,
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type,
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iv: meta.id
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});
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};
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fileReader.readAsArrayBuffer(blob);
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};
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xhr.open('get', this.url);
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xhr.responseType = 'blob';
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xhr.send();
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});
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}
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async download() {
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const key = await this.key;
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const file = await this.downloadFile();
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this.emit('decrypting');
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const plaintext = await window.crypto.subtle.decrypt(
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{
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name: 'AES-GCM',
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iv: hexToArray(file.iv),
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tagLength: 128
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},
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key,
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file.data
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);
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return {
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plaintext,
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name: decodeURIComponent(file.name),
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type: file.type
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};
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}
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}
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