Moving to SHAKE256

Author: tomekmarchi

udsp/cryptoMiddleware/cipherSuite/Kyber768_xChaCha.js

@@ -26,7 +26,7 @@ const {
 	randomBuffer,
 	toBase64,
 	toHex,
-	combineKeys,
+	combineKeysSHAKE256,
 	clearBuffer,
 	clearBuffers
 } = defaultCrypto;
@@ -75,8 +75,8 @@ export const kyber768_xChaCha = {
 		const sharedSecret = source.sharedSecret;
 		const oldTransmitKey = source.transmitKey;
 		const oldReceiveKey = source.receiveKey;
-		source.transmitKey = combineKeys(oldTransmitKey, source.sharedSecret);
-		source.receiveKey = combineKeys(oldReceiveKey, source.sharedSecret);
+		source.transmitKey = combineKeysSHAKE256(oldTransmitKey, source.sharedSecret);
+		source.receiveKey = combineKeysSHAKE256(oldReceiveKey, source.sharedSecret);
 		clearBuffer(oldTransmitKey);
 		clearBuffer(oldReceiveKey);
 		clearBuffer(source.sharedSecret);
@@ -148,8 +148,8 @@ export const kyber768_xChaCha = {
 		const sharedSecret = source.sharedSecret;
 		const oldTransmitKey = source.transmitKey;
 		const oldReceiveKey = source.receiveKey;
-		source.transmitKey = combineKeys(oldTransmitKey, source.sharedSecret);
-		source.receiveKey = combineKeys(oldReceiveKey, source.sharedSecret);
+		source.transmitKey = combineKeysSHAKE256(oldTransmitKey, source.sharedSecret);
+		source.receiveKey = combineKeysSHAKE256(oldReceiveKey, source.sharedSecret);
 		clearBuffer(oldTransmitKey);
 		clearBuffer(oldReceiveKey);
 		clearBuffer(source.sharedSecret);

udsp/cryptoMiddleware/cipherSuite/x25519_Kyber768_xChaCha.js

@@ -29,6 +29,7 @@ import { kyber768_x25519 } from '../keyExchange/kyber768_x25519.js';
 import { shake256 } from '@noble/hashes/sha3';
 import { x25519_kyber768Half_xchacha20 } from './x25519_Kyber768Half_xChaCha.js';
 const hashFunction = shake256;
+// CHANGE THIS TO BE SAFE TO ITS OWN AT kyber768_x25519
 const { clientSetSession } = x25519_kyber768Half_xchacha20;
 const {
 	serverSetSessionAttach,
@@ -38,7 +39,6 @@ const {
 	randomBuffer,
 	toBase64,
 	toHex,
-	combineKeys,
 } = defaultCrypto;
 const {
 	clientInitializeSession,

udsp/cryptoMiddleware/cipherSuite/x25519_xChaCha.js

@@ -28,7 +28,6 @@ const {
 	clearBuffer,
 	clearBuffers,
 	getX25519Key,
-	combineKeys,
 	combineSessionKeys
 } = defaultCrypto;
 const { id: encryptionKeypairID } = x25519;

udsp/cryptoMiddleware/keyExchange/kyber768_x25519.js

@@ -1,3 +1,5 @@
+// CONVERT THIS TO SHAKE256 AFTER x25519_blake3 is done
+// Consider SHAKE256 as the hash function for x25519_shake256 variant
 import * as defaultCrypto from '#crypto';
 import {
 	clientSetSession,

utilities/crypto.js

@@ -6,7 +6,9 @@ const sodiumLib = sodium?.default || sodium;
 const { randombytes_buf } = sodiumLib;
 import { clear, isBuffer } from '@universalweb/acid';
 import { blake3 } from '@noble/hashes/blake3';
-export const defaultHashFunction = blake3;
+import { shake256 } from '@noble/hashes/sha3';
+export const basicHashFunction = blake3;
+export const defaultHashFunction = shake256;
 export const int32 = 32;
 export const int64 = 64;
 export function toBuffer(source) {
@@ -86,6 +88,11 @@ export function cleanKeypair(source) {
 	return source;
 }
 export function combineKeys(...sources) {
+	// console.log('Combine', key1, key2);
+	const combinedKeys = basicHashFunction(Buffer.concat(sources));
+	return combinedKeys;
+}
+export function combineKeysSHAKE256(...sources) {
 	// console.log('Combine', key1, key2);
 	const combinedKeys = defaultHashFunction(Buffer.concat(sources));
 	return combinedKeys;
@@ -101,7 +108,7 @@ export function combineSessionKeys(oldTransmitKey, oldReceiveKey, source) {
 }
 export function combineKeysFreeMemory(...sources) {
 	// console.log('Combine', key1, key2);
-	const combinedKeys = defaultHashFunction(Buffer.concat(sources));
+	const combinedKeys = basicHashFunction(Buffer.concat(sources));
 	clearBuffers(...sources);
 	return combinedKeys;
 }