From 87d7ed9c41e19d2601e7ca1f0074c885b786a3a3 Mon Sep 17 00:00:00 2001
From: morrigan <belma.dzi@gmail.com>
Date: Wed, 6 Nov 2019 15:45:28 +0100
Subject: [PATCH] Fix todos and finish stage 1

---
 src/xx.ts       | 21 ++++++++++++++-------
 test/xx.test.ts |  5 ++++-
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/xx.ts b/src/xx.ts
index 193076b..b9d94dc 100644
--- a/src/xx.ts
+++ b/src/xx.ts
@@ -74,7 +74,7 @@ export class XXHandshake {
   }
 
   private dh(privateKey: bytes32, publicKey: bytes32) : bytes32 {
-    const derived = x25519.derive(privateKey, publicKey);
+    const derived = x25519.derive(publicKey, privateKey);
     const result = Buffer.alloc(32);
     derived.copy(result);
     return result;
@@ -268,14 +268,18 @@ export class XXHandshake {
   }
 
   private async readMessageA(hs: HandshakeState, message: MessageBuffer) : Promise<bytes> {
-    // TODO: validate public key here
+    if (x25519.publicKeyVerify(message.ne)) {
+      hs.re = message.ne;
+    }
 
     this.mixHash(hs.ss, hs.re);
     return await this.decryptAndHash(hs.ss, message.ciphertext);
   }
 
   private async readMessageB(hs: HandshakeState, message: MessageBuffer) : Promise<bytes> {
-    // TODO: validate public key here
+    if (x25519.publicKeyVerify(message.ne)) {
+      hs.re = message.ne;
+    }
 
     this.mixHash(hs.ss, hs.re);
     if (!hs.e) {
@@ -283,16 +287,19 @@ export class XXHandshake {
     }
     this.mixKey(hs.ss, this.dh(hs.e.privateKey, hs.re));
     const ns = await this.decryptAndHash(hs.ss, message.ns);
-    // TODO: validate ns here as public key
-    hs.rs = ns;
+    if (ns.length === 32 && x25519.publicKeyVerify(message.ns)) {
+      hs.rs = ns;
+    }
     this.mixKey(hs.ss, this.dh(hs.e.privateKey, hs.rs));
     return await this.decryptAndHash(hs.ss, message.ciphertext);
   }
 
   private async readMessageC(hs: HandshakeState, message: MessageBuffer) {
     const ns = await this.decryptAndHash(hs.ss, message.ns);
-    // TODO: validate ns here as public key
-    hs.rs = ns;
+    if (ns.length === 32 && x25519.publicKeyVerify(message.ns)) {
+      hs.rs = ns;
+    }
+
     if (!hs.e) {
       throw new Error("Handshake state `e` param is missing.");
     }
diff --git a/test/xx.test.ts b/test/xx.test.ts
index 15a7cc2..a9a9470 100644
--- a/test/xx.test.ts
+++ b/test/xx.test.ts
@@ -85,11 +85,14 @@ describe("Index", () => {
     const payloadRespEnc = NoiseHandshakePayload.encode(payloadResp).finish();
 
     const message1 = Buffer.concat([message, payloadRespEnc]);
-    console.log("nsResp: ", nsResp)
     const messageBuffer2 = await xx.sendMessage(nsResp, message1);
 
     expect(messageBuffer2.ne.length).not.equal(0);
     expect(messageBuffer2.ns.length).not.equal(0);
+
+    // initiator receive payload
+    const plaintext2 = await xx.RecvMessage(nsInit, messageBuffer2);
+    console.log(plaintext2);
   }
 
   it("Test handshake", async () => {