From 59d274df751544c59e57b6aa4f5aa1e92cf13a84 Mon Sep 17 00:00:00 2001
From: isrand <isrand@protonmail.com>
Date: Thu, 6 Mar 2025 10:49:20 +0100
Subject: [PATCH] Fix KyberSlash Issue

---
 kyber1024.js | 7 ++++++-
 kyber512.js  | 7 ++++++-
 kyber768.js  | 7 ++++++-
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/kyber1024.js b/kyber1024.js
index 920c27e..aab0b54 100644
--- a/kyber1024.js
+++ b/kyber1024.js
@@ -457,7 +457,12 @@ function polyToMsg(a) {
     for (let i = 0; i < paramsN / 8; i++) {
         msg[i] = 0;
         for (let j = 0; j < 8; j++) {
-            t = (((uint16(a2[8 * i + j]) << 1) + uint16(paramsQ / 2)) / uint16(paramsQ)) & 1;
+            t = uint32(a2[8 * i + j]);
+            t <<= 1;
+            t += 1665;
+            t *= 80635;
+            t >>= 28;
+            t &= 1;
             msg[i] |= byte(t << j);
         }
     }
diff --git a/kyber512.js b/kyber512.js
index 3ec8c55..2728780 100644
--- a/kyber512.js
+++ b/kyber512.js
@@ -458,7 +458,12 @@ function polyToMsg(a) {
     for (let i = 0; i < paramsN / 8; i++) {
         msg[i] = 0;
         for (let j = 0; j < 8; j++) {
-            t = (((uint16(a2[8 * i + j]) << 1) + uint16(paramsQ / 2)) / uint16(paramsQ)) & 1;
+            t = uint32(a2[8 * i + j]);
+            t <<= 1;
+            t += 1665;
+            t *= 80635;
+            t >>= 28;
+            t &= 1;
             msg[i] |= byte(t << j);
         }
     }
diff --git a/kyber768.js b/kyber768.js
index d0a5ef1..2d92ae0 100644
--- a/kyber768.js
+++ b/kyber768.js
@@ -458,7 +458,12 @@ function polyToMsg(a) {
     for (let i = 0; i < paramsN / 8; i++) {
         msg[i] = 0;
         for (let j = 0; j < 8; j++) {
-            t = (((uint16(a2[8 * i + j]) << 1) + uint16(paramsQ / 2)) / uint16(paramsQ)) & 1;
+            t = uint32(a2[8 * i + j]);
+            t <<= 1;
+            t += 1665;
+            t *= 80635;
+            t >>= 28;
+            t &= 1;
             msg[i] |= byte(t << j);
         }
     }