From 412d214a997149e4cb0dc3cbc7ac6e3e5e1ad2d8 Mon Sep 17 00:00:00 2001
From: rusefillc <rusefillc@gmail.com>
Date: Sat, 3 Jun 2023 01:30:48 -0400
Subject: [PATCH] we know a secret!

---
 src/main/java/com/rusefi/uds/KeyCalculator.java | 14 +++++++++++---
 src/test/java/com/rusefi/uds/SecurityTest.java  | 14 ++++++++++++--
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/main/java/com/rusefi/uds/KeyCalculator.java b/src/main/java/com/rusefi/uds/KeyCalculator.java
index bf655e4..46f8360 100644
--- a/src/main/java/com/rusefi/uds/KeyCalculator.java
+++ b/src/main/java/com/rusefi/uds/KeyCalculator.java
@@ -1,10 +1,18 @@
 package com.rusefi.uds;
 
 public class KeyCalculator {
-    //private static final int SECRET = 0x57649392;
+    private static final int MAIN_APP_SECRET = 0x57649392;
     private static final int BOOTLOADER_SECRET = 0xB24F5249;
 
-    public static int udsSecurityCalcKey(int seed, int rnd) {
+    public static int udsBootloaderSecurityCalcKey(int seed, int rnd) {
+        return udsSecurityCalcKey(BOOTLOADER_SECRET, seed, rnd);
+    }
+
+    public static int udsMainAppSecurityCalcKey(int seed, int rnd) {
+        return udsSecurityCalcKey(MAIN_APP_SECRET, seed, rnd);
+    }
+
+    private static int udsSecurityCalcKey(int secret, int seed, int rnd) {
         if (rnd < 220) {
             rnd += 35;
         } else {
@@ -13,7 +21,7 @@ public class KeyCalculator {
 
         for (int i = 0; i < rnd; i++) {
             if (seed < 0) {
-                seed = BOOTLOADER_SECRET ^ seed << 1;
+                seed = secret ^ seed << 1;
             } else {
                 seed <<= 1;
             }
diff --git a/src/test/java/com/rusefi/uds/SecurityTest.java b/src/test/java/com/rusefi/uds/SecurityTest.java
index 25fa2a0..1706480 100644
--- a/src/test/java/com/rusefi/uds/SecurityTest.java
+++ b/src/test/java/com/rusefi/uds/SecurityTest.java
@@ -7,7 +7,17 @@ import static org.junit.Assert.assertEquals;
 public class SecurityTest {
     @Test
     public void testCalcKey() {
-        int key = KeyCalculator.udsSecurityCalcKey(0x5D8A2010, 0xF0);
-        assertEquals("Got " + String.format("%x", key), 0xc42f15ae, key);
+        {
+            int key = KeyCalculator.udsBootloaderSecurityCalcKey(0x5D8A2010, 0xF0);
+            assertEquals("Got " + String.format("%x", key), 0xc42f15ae, key);
+        }
+        {
+            int key = KeyCalculator.udsBootloaderSecurityCalcKey(0x5D8A202C, 0xF0);
+            assertEquals("Got " + String.format("%x", key), 0xAEE52AA2, key);
+        }
+        {
+            int key = KeyCalculator.udsMainAppSecurityCalcKey(0x5DA0B808, 0xA4);
+            assertEquals("Got " + String.format("%x", key), 0x001B6F78, key);
+        }
     }
 }