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session-desktop/ts/session/crypto/index.ts

87 lines
3.0 KiB
TypeScript

import crypto from 'crypto';
import libsodiumwrappers from 'libsodium-wrappers-sumo';
import * as DecryptedAttachmentsManager from './DecryptedAttachmentsManager';
import * as MessageEncrypter from './MessageEncrypter';
import { ECKeyPair } from '../../receiver/keypairs';
import { toHex } from '../utils/String';
export { DecryptedAttachmentsManager, MessageEncrypter };
export type LibSodiumWrappers = typeof libsodiumwrappers;
export async function getSodiumRenderer(): Promise<LibSodiumWrappers> {
await libsodiumwrappers.ready;
return libsodiumwrappers;
}
export const sha256 = (s: string) => {
return crypto.createHash('sha256').update(s).digest('base64');
};
export const concatUInt8Array = (...args: Array<Uint8Array>): Uint8Array => {
const totalLength = args.reduce((acc, current) => acc + current.length, 0);
const concatted = new Uint8Array(totalLength);
let currentIndex = 0;
args.forEach(arr => {
concatted.set(arr, currentIndex);
currentIndex += arr.length;
});
return concatted;
};
/**
* Returns a generated curve25519 hex public key being of length 66 and starting with 05.
* For a closed group, we have one publicKey (with prefix) used for polling (this function),
* and one keypair without prefix used for encoding of the messages (function generateCurve25519KeyPairWithoutPrefix).
*/
export async function generateClosedGroupPublicKey() {
const sodium = await getSodiumRenderer();
const ed25519KeyPair = sodium.crypto_sign_keypair();
const x25519PublicKey = sodium.crypto_sign_ed25519_pk_to_curve25519(ed25519KeyPair.publicKey);
// prepend version byte (coming from `processKeys(raw_keys)`)
const origPub = new Uint8Array(x25519PublicKey);
const prependedX25519PublicKey = new Uint8Array(33);
prependedX25519PublicKey.set(origPub, 1);
prependedX25519PublicKey[0] = 5;
return toHex(prependedX25519PublicKey);
}
/**
* Returns a generated ed25519 hex with a public key being of length 66 and starting with 03.
*/
export async function generateGroupV3Keypair() {
const sodium = await getSodiumRenderer();
const ed25519KeyPair = sodium.crypto_sign_keypair();
const publicKey = new Uint8Array(ed25519KeyPair.publicKey);
const preprendedPubkey = new Uint8Array(33);
preprendedPubkey.set(publicKey, 1);
preprendedPubkey[0] = 3;
return { pubkey: toHex(preprendedPubkey), privateKey: toHex(ed25519KeyPair.privateKey) };
}
/**
* Returns a generated curve25519 keypair without the prefix on the public key.
* This should be used for the generation of encryption keypairs for a closed group
*/
export async function generateCurve25519KeyPairWithoutPrefix(): Promise<ECKeyPair | null> {
const sodium = await getSodiumRenderer();
try {
const ed25519KeyPair = sodium.crypto_sign_keypair();
const x25519PublicKey = sodium.crypto_sign_ed25519_pk_to_curve25519(ed25519KeyPair.publicKey);
const x25519SecretKey = sodium.crypto_sign_ed25519_sk_to_curve25519(ed25519KeyPair.privateKey);
return new ECKeyPair(x25519PublicKey, x25519SecretKey);
} catch (err) {
return null;
}
}