drop.chapril.org-firefoxsend/frontend/src/fileReceiver.js
Danny Coates dd0ab710de
format
2017-07-25 12:21:07 -07:00

104 lines
2.8 KiB
JavaScript

const EventEmitter = require('events');
const { hexToArray } = require('./utils');
class FileReceiver extends EventEmitter {
constructor() {
super();
}
download() {
return Promise.all([
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 fileReader = new FileReader();
fileReader.onload = function() {
const meta = JSON.parse(xhr.getResponseHeader('X-File-Metadata'));
resolve({
data: this.result,
aad: meta.aad,
filename: meta.filename,
iv: meta.id
});
};
fileReader.readAsArrayBuffer(blob);
};
xhr.open('get', '/assets' + location.pathname.slice(0, -1), true);
xhr.responseType = 'blob';
xhr.send();
}),
window.crypto.subtle.importKey(
'jwk',
{
kty: 'oct',
k: location.hash.slice(1),
alg: 'A128GCM',
ext: true
},
{
name: 'AES-GCM'
},
true,
['encrypt', 'decrypt']
)
])
.then(([fdata, key]) => {
this.emit('decrypting', true);
return Promise.all([
window.crypto.subtle
.decrypt(
{
name: 'AES-GCM',
iv: hexToArray(fdata.iv),
additionalData: hexToArray(fdata.aad),
tagLength: 128
},
key,
fdata.data
)
.then(decrypted => {
this.emit('decrypting', false);
return Promise.resolve(decrypted);
}),
fdata.filename,
hexToArray(fdata.aad)
]);
})
.then(([decrypted, fname, proposedHash]) => {
this.emit('hashing', true);
return window.crypto.subtle
.digest('SHA-256', decrypted)
.then(calculatedHash => {
this.emit('hashing', false);
const integrity =
new Uint8Array(calculatedHash).toString() ===
proposedHash.toString();
if (!integrity) {
this.emit('unsafe', true);
return Promise.reject();
} else {
this.emit('safe', true);
return Promise.all([decrypted, decodeURIComponent(fname)]);
}
});
});
}
}
module.exports = FileReceiver;