62 lines
1.8 KiB
TypeScript
62 lines
1.8 KiB
TypeScript
|
// Copyright 2020-2021 Signal Messenger, LLC
|
||
|
|
// SPDX-License-Identifier: AGPL-3.0-only
|
||
|
|
|
||
|
|
import { isNumber, omit } from 'lodash';
|
||
|
|
|
||
|
|
import { strictAssert } from '../util/assert';
|
||
|
|
import { dropNull } from '../util/dropNull';
|
||
|
|
import { DownloadedAttachmentType } from '../types/Attachment';
|
||
|
|
import * as MIME from '../types/MIME';
|
||
|
|
import * as Bytes from '../Bytes';
|
||
|
|
import { typedArrayToArrayBuffer } from '../Crypto';
|
||
|
|
|
||
|
|
import Crypto from './Crypto';
|
||
|
|
import { ProcessedAttachment } from './Types.d';
|
||
|
|
import type { WebAPIType } from './WebAPI';
|
||
|
|
|
||
|
|
export async function downloadAttachment(
|
||
|
|
server: WebAPIType,
|
||
|
|
attachment: ProcessedAttachment
|
||
|
|
): Promise<DownloadedAttachmentType> {
|
||
|
|
const cdnId = attachment.cdnId || attachment.cdnKey;
|
||
|
|
const { cdnNumber } = attachment;
|
||
|
|
|
||
|
|
if (!cdnId) {
|
||
|
|
throw new Error('downloadAttachment: Attachment was missing cdnId!');
|
||
|
|
}
|
||
|
|
|
||
|
|
strictAssert(cdnId, 'attachment without cdnId');
|
||
|
|
const encrypted = await server.getAttachment(cdnId, dropNull(cdnNumber));
|
||
|
|
const { key, digest, size, contentType } = attachment;
|
||
|
|
|
||
|
|
if (!digest) {
|
||
|
|
throw new Error('Failure: Ask sender to update Signal and resend.');
|
||
|
|
}
|
||
|
|
|
||
|
|
strictAssert(key, 'attachment has no key');
|
||
|
|
strictAssert(digest, 'attachment has no digest');
|
||
|
|
|
||
|
|
const paddedData = await Crypto.decryptAttachment(
|
||
|
|
encrypted,
|
||
|
|
typedArrayToArrayBuffer(Bytes.fromBase64(key)),
|
||
|
|
typedArrayToArrayBuffer(Bytes.fromBase64(digest))
|
||
|
|
);
|
||
|
|
|
||
|
|
if (!isNumber(size)) {
|
||
|
|
throw new Error(
|
||
|
|
`downloadAttachment: Size was not provided, actual size was ${paddedData.byteLength}`
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
const data = window.Signal.Crypto.getFirstBytes(paddedData, size);
|
||
|
|
|
||
|
|
return {
|
||
|
|
...omit(attachment, 'digest', 'key'),
|
||
|
|
|
||
|
|
contentType: contentType
|
||
|
|
? MIME.fromString(contentType)
|
||
|
|
: MIME.APPLICATION_OCTET_STREAM,
|
||
|
|
data,
|
||
|
|
};
|
||
|
|
}
|