Merge pull request #40 from yusefnapora/fix-xx-message-c

remove empty ephemeral key from XX message C

src/encoder.ts

@@ -25,6 +25,10 @@ export function encode1(message: MessageBuffer): bytes {
   return Buffer.concat([message.ne, message.ns, message.ciphertext]);
 }
 
+export function encode2(message: MessageBuffer): bytes {
+  return Buffer.concat([message.ns, message.ciphertext]);
+}
+
 export function decode0(input: bytes): MessageBuffer {
   if (input.length < 32) {
     throw new Error("Cannot decode stage 0 MessageBuffer: length less than 32 bytes.");
@@ -39,7 +43,7 @@ export function decode0(input: bytes): MessageBuffer {
 
 export function decode1(input: bytes): MessageBuffer {
   if (input.length < 80) {
-    throw new Error("Cannot decode stage 0 MessageBuffer: length less than 96 bytes.");
+    throw new Error("Cannot decode stage 1 MessageBuffer: length less than 80 bytes.");
   }
 
   return {
@@ -48,3 +52,15 @@ export function decode1(input: bytes): MessageBuffer {
     ciphertext: input.slice(80, input.length),
   }
 }
+
+export function decode2(input: bytes): MessageBuffer {
+  if (input.length < 48) {
+    throw new Error("Cannot decode stage 2 MessageBuffer: length less than 48 bytes.");
+  }
+
+  return {
+    ne: Buffer.alloc(0),
+    ns: input.slice(0, 48),
+    ciphertext: input.slice(48, input.length),
+  }
+}

src/handshake-xx.ts

@@ -11,7 +11,7 @@ import {
   verifySignedPayload,
 } from "./utils";
 import { logger } from "./logger";
-import { decode0, decode1, encode0, encode1 } from "./encoder";
+import {decode0, decode1, decode2, encode0, encode1, encode2} from "./encoder";
 import { WrappedConnection } from "./noise";
 import PeerId from "peer-id";
 
@@ -99,11 +99,11 @@ export class XXHandshake implements IHandshake {
     if (this.isInitiator) {
       logger('Stage 2 - Initiator sending third handshake message.');
       const messageBuffer = this.xx.sendMessage(this.session, this.payload);
-      this.connection.writeLP(encode1(messageBuffer));
+      this.connection.writeLP(encode2(messageBuffer));
       logger('Stage 2 - Initiator sent message with signed payload.');
     } else {
       logger('Stage 2 - Responder waiting for third handshake message...');
-      const receivedMessageBuffer = decode1((await this.connection.readLP()).slice());
+      const receivedMessageBuffer = decode2((await this.connection.readLP()).slice());
       const {plaintext, valid} = this.xx.recvMessage(this.session, receivedMessageBuffer);
       if(!valid) {
         throw new Error("xx handshake stage 2 validation fail");

test/noise.test.ts

@@ -1,18 +1,13 @@
-import { expect, assert } from "chai";
+import {assert, expect} from "chai";
 import DuplexPair from 'it-pair/duplex';
-import { Noise } from "../src";
+import {Noise} from "../src";
 import {createPeerIdsFromFixtures} from "./fixtures/peer";
 import Wrap from "it-pb-rpc";
-import { random } from "bcrypto";
+import {random} from "bcrypto";
 import sinon from "sinon";
 import {XXHandshake} from "../src/handshake-xx";
-import {
-  createHandshakePayload,
-  generateKeypair,
-  getHandshakePayload, getPayload,
-  signPayload
-} from "../src/utils";
-import {decode0, decode1, encode1, uint16BEDecode, uint16BEEncode} from "../src/encoder";
+import {createHandshakePayload, generateKeypair, getHandshakePayload, getPayload, signPayload} from "../src/utils";
+import {decode0, decode2, encode1, uint16BEDecode, uint16BEEncode} from "../src/encoder";
 import {XX} from "../src/handshakes/xx";
 import {Buffer} from "buffer";
 import {getKeyPairFromPeerId} from "./utils";
@@ -89,7 +84,7 @@ describe("Noise", () => {
         wrapped.writeLP(encode1(messageBuffer));
 
         // Stage 2 - finish handshake
-        receivedMessageBuffer = decode1((await wrapped.readLP()).slice());
+        receivedMessageBuffer = decode2((await wrapped.readLP()).slice());
         xx.recvMessage(handshake.session, receivedMessageBuffer);
         return {wrapped, handshake};
       })(),