signal-desktop/ts/util/safetyNumber.ts
2023-11-01 15:55:30 -07:00

70 lines
2 KiB
TypeScript

// Copyright 2020 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import { PublicKey, Fingerprint } from '@signalapp/libsignal-client';
import type { ConversationType } from '../state/ducks/conversations';
import { assertDev } from './assert';
import { uuidToBytes } from './uuidToBytes';
import * as log from '../logging/log';
import type { SafetyNumberType } from '../types/safetyNumber';
import { isAciString } from './isAciString';
const ITERATION_COUNT = 5200;
const SERVICE_ID_VERSION = 2;
// Number of digits in a safety number block
const BLOCK_SIZE = 5;
export async function generateSafetyNumber(
contact: ConversationType
): Promise<SafetyNumberType> {
const logId = `generateSafetyNumbers(${contact.id})`;
log.info(`${logId}: starting`);
const { storage } = window.textsecure;
const ourAci = storage.user.getCheckedAci();
const us = storage.protocol.getIdentityRecord(ourAci);
const ourKeyBuffer = us ? us.publicKey : null;
const theirAci = isAciString(contact.serviceId)
? contact.serviceId
: undefined;
const them = theirAci
? await storage.protocol.getOrMigrateIdentityRecord(theirAci)
: undefined;
const theirKeyBuffer = them?.publicKey;
if (!ourKeyBuffer) {
throw new Error('Could not load our key');
}
if (!theirKeyBuffer) {
throw new Error('Could not load their key');
}
const ourKey = PublicKey.deserialize(Buffer.from(ourKeyBuffer));
const theirKey = PublicKey.deserialize(Buffer.from(theirKeyBuffer));
assertDev(theirAci, 'Should have their serviceId');
const fingerprint = Fingerprint.new(
ITERATION_COUNT,
SERVICE_ID_VERSION,
Buffer.from(uuidToBytes(ourAci)),
ourKey,
Buffer.from(uuidToBytes(theirAci)),
theirKey
);
const securityNumber = fingerprint.displayableFingerprint().toString();
const numberBlocks = [];
for (let i = 0; i < securityNumber.length; i += BLOCK_SIZE) {
numberBlocks.push(securityNumber.substring(i, i + BLOCK_SIZE));
}
const qrData = fingerprint.scannableFingerprint().toBuffer();
return { numberBlocks, qrData };
}