drop.chapril.org-firefoxsend/app/fileReceiver.js
2017-08-25 09:44:52 -07:00

101 lines
2.2 KiB
JavaScript

import Nanobus from 'nanobus';
import { hexToArray, bytes } from './utils';
export default class FileReceiver extends Nanobus {
constructor(url, k) {
super('FileReceiver');
this.key = window.crypto.subtle.importKey(
'jwk',
{
k,
kty: 'oct',
alg: 'A128GCM',
ext: true
},
{
name: 'AES-GCM'
},
false,
['decrypt']
);
this.url = url;
this.msg = 'fileSizeProgress';
this.progress = [0, 1];
}
get progressRatio() {
return this.progress[0] / this.progress[1];
}
get sizes() {
return {
partialSize: bytes(this.progress[0]),
totalSize: bytes(this.progress[1])
};
}
cancel() {
// TODO
}
downloadFile() {
return new Promise((resolve, reject) => {
const xhr = new XMLHttpRequest();
xhr.onprogress = event => {
if (event.lengthComputable && event.target.status !== 404) {
this.progress = [event.loaded, event.total];
this.emit('progress', this.progress);
}
};
xhr.onload = function(event) {
if (xhr.status === 404) {
reject(new Error('notfound'));
return;
}
const blob = new Blob([this.response]);
const meta = JSON.parse(xhr.getResponseHeader('X-File-Metadata'));
const fileReader = new FileReader();
fileReader.onload = function() {
resolve({
data: this.result,
name: meta.filename,
type: meta.mimeType,
iv: meta.id
});
};
fileReader.readAsArrayBuffer(blob);
};
xhr.open('get', this.url);
xhr.responseType = 'blob';
xhr.send();
});
}
async download() {
const key = await this.key;
const file = await this.downloadFile();
this.msg = 'decryptingFile';
this.emit('decrypting');
const plaintext = await window.crypto.subtle.decrypt(
{
name: 'AES-GCM',
iv: hexToArray(file.iv),
tagLength: 128
},
key,
file.data
);
this.msg = 'downloadFinish';
return {
plaintext,
name: decodeURIComponent(file.name),
type: file.type
};
}
}