Use protobuf instead of JSON for direct messages

CHANGELOG.md

@@ -26,6 +26,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `WakuMessage` version 1 is partially supported, enabling asymmetrical encryption and signature of messages;
   this can be done by passing keys to `WakuMessage.from*` and `WakuMessage.decode*` methods.
 - Examples (eth-dm): Use Waku Message version 1 encryption scheme instead of `eth-crypto`.
+- Examples (eth-dm): Use Protobuf for direct messages instead of JSON ([#214](https://github.com/status-im/js-waku/issues/214)).
 
 ### Fixed
 - Disable `keepAlive` if set to `0`.

examples/eth-dm/src/messaging/SendMessage.tsx

@@ -8,7 +8,8 @@ import {
 } from '@material-ui/core';
 import React, { ChangeEvent, useState, KeyboardEvent } from 'react';
 import { Waku, WakuMessage } from 'js-waku';
-import { DirectMessage, encode } from './wire';
+import { hexToBuf } from 'js-waku/lib/utils';
+import { DirectMessage } from './wire';
 import { DirectMessageContentTopic } from '../waku';
 
 const useStyles = makeStyles((theme) => ({
@@ -108,12 +109,12 @@ async function encodeEncryptedWakuMessage(
   publicKey: string,
   address: string
 ): Promise<WakuMessage> {
-  const directMsg: DirectMessage = {
-    toAddress: address,
+  const directMsg = new DirectMessage({
+    toAddress: hexToBuf(address),
     message: message,
-  };
+  });
 
-  const payload = encode(directMsg);
+  const payload = directMsg.encode();
   return WakuMessage.fromBytes(payload, {
     contentTopic: DirectMessageContentTopic,
     encPublicKey: publicKey,

examples/eth-dm/src/messaging/wire.ts

@@ -55,21 +55,43 @@ export class PublicKeyMessage {
   }
 }
 
-/**
- * Direct Encrypted Message used for private communication over the Waku network.
- */
-export interface DirectMessage {
-  toAddress: string;
+export interface DirectMessagePayload {
+  toAddress: Uint8Array;
   message: string;
 }
 
-export function encode<T>(msg: T): Buffer {
-  const jsonStr = JSON.stringify(msg);
-  return Buffer.from(jsonStr, 'utf-8');
+/**
+ * Direct Encrypted Message used for private communication over the Waku network.
+ */
+export class DirectMessage {
+  private static Type = new Type('DirectMessage')
+    .add(new Field('toAddress', 1, 'bytes'))
+    .add(new Field('message', 2, 'string'));
+  private static Root = new Root().define('messages').add(DirectMessage.Type);
+
+  constructor(public payload: DirectMessagePayload) {}
+
+  public encode(): Uint8Array {
+    const message = DirectMessage.Type.create(this.payload);
+    return DirectMessage.Type.encode(message).finish();
   }
 
-export function decode<T>(bytes: Uint8Array): T {
-  const buf = Buffer.from(bytes);
-  const str = buf.toString('utf-8');
-  return JSON.parse(str);
+  public static decode(bytes: Uint8Array | Buffer): DirectMessage | undefined {
+    const payload = DirectMessage.Type.decode(
+      bytes
+    ) as unknown as DirectMessagePayload;
+    if (!payload.toAddress || !payload.message) {
+      console.log('Field missing on decoded Direct Message', payload);
+      return;
+    }
+    return new DirectMessage(payload);
+  }
+
+  get toAddress(): Uint8Array {
+    return this.payload.toAddress;
+  }
+
+  get message(): string {
+    return this.payload.message;
+  }
 }

examples/eth-dm/src/waku.ts

@@ -1,12 +1,12 @@
 import { Dispatch, SetStateAction } from 'react';
 import { getStatusFleetNodes, Waku, WakuMessage } from 'js-waku';
-import { decode, DirectMessage, PublicKeyMessage } from './messaging/wire';
+import { DirectMessage, PublicKeyMessage } from './messaging/wire';
 import { validatePublicKeyMessage } from './crypto';
 import { Message } from './messaging/Messages';
 import { bufToHex, equalByteArrays } from 'js-waku/lib/utils';
 
 export const PublicKeyContentTopic = '/eth-dm/1/public-key/proto';
-export const DirectMessageContentTopic = '/eth-dm/1/direct-message/json';
+export const DirectMessageContentTopic = '/eth-dm/1/direct-message/proto';
 
 export async function initWaku(): Promise<Waku> {
   const waku = await Waku.create({});
@@ -64,8 +64,11 @@ export async function handleDirectMessage(
 ) {
   console.log('Direct Message received:', wakuMsg);
   if (!wakuMsg.payload) return;
-  const directMessage: DirectMessage = decode(wakuMsg.payload);
-
+  const directMessage = DirectMessage.decode(wakuMsg.payload);
+  if (!directMessage) {
+    console.log('Failed to decode Direct Message');
+    return;
+  }
   if (!equalByteArrays(directMessage.toAddress, address)) return;
 
   const timestamp = wakuMsg.timestamp ? wakuMsg.timestamp : new Date();

src/lib/waku_message/version_1.ts

@@ -28,7 +28,7 @@ export function clearEncode(
 ): { payload: Uint8Array; sig?: Signature } {
   let envelope = Buffer.from([0]); // No flags
   envelope = addPayloadSizeField(envelope, messagePayload);
-  envelope = Buffer.concat([envelope, messagePayload]);
+  envelope = Buffer.concat([envelope, Buffer.from(messagePayload)]);
 
   // Calculate padding:
   let rawSize =