From f675456c0b803a1f92dbd311fbc489ab3c32cfcc Mon Sep 17 00:00:00 2001
From: Vlad Lupashevskyi <vlad@lupashevskyi.com>
Date: Tue, 8 Aug 2023 23:19:30 +0200
Subject: [PATCH] Introduce seed key for EGS53

---
 .../UnlockECU/Security/VGSSecurityAlgoExt.cs  | 35 +++++++++++++++++++
 UnlockECU/db.json                             | 21 +++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 UnlockECU/UnlockECU/Security/VGSSecurityAlgoExt.cs

diff --git a/UnlockECU/UnlockECU/Security/VGSSecurityAlgoExt.cs b/UnlockECU/UnlockECU/Security/VGSSecurityAlgoExt.cs
new file mode 100644
index 0000000..3de80ef
--- /dev/null
+++ b/UnlockECU/UnlockECU/Security/VGSSecurityAlgoExt.cs
@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+
+namespace UnlockECU
+{
+    /// <summary>
+    /// Implementation of extended VGS Algo with different keys for multiplication and xor
+    /// </summary>
+    class VGSSecurityAlgoExt : SecurityProvider
+    {
+        public override bool GenerateKey(byte[] inSeed, byte[] outKey, int accessLevel, List<Parameter> parameters)
+        {
+            byte[] cryptoKeyMultBytes = GetParameterBytearray(parameters, "M");
+            uint cryptoKeyMult = BytesToInt(cryptoKeyMultBytes, Endian.Big);
+
+            byte[] cryptoKeyXorBytes = GetParameterBytearray(parameters, "X");
+            uint cryptoKeyXor = BytesToInt(cryptoKeyXorBytes, Endian.Big);
+
+            if ((inSeed.Length != 4) || (outKey.Length != 4))
+            {
+                return false;
+            }
+
+            long seed = BytesToInt(inSeed, Endian.Big);
+            long seedKey = cryptoKeyMult * (cryptoKeyXor ^ seed);
+
+            IntToBytes((uint)seedKey, outKey, Endian.Big);
+            return true;
+        }
+        public override string GetProviderName()
+        {
+            return "VGSSecurityAlgoExt";
+        }
+    }
+}
diff --git a/UnlockECU/db.json b/UnlockECU/db.json
index 984e218..c58c1fd 100644
--- a/UnlockECU/db.json
+++ b/UnlockECU/db.json
@@ -11818,6 +11818,27 @@
         "DataType": "ByteArray"
       }
     ]
+  },
+    {
+    "EcuName": "EGS53",
+    "Aliases": [],
+    "AccessLevel": 1,
+    "SeedLength": 4,
+    "KeyLength": 4,
+    "Provider": "VGSSecurityAlgoExt",
+    "Origin": "EGS53_27_05@VladLupashevskyi-@rnd-ash",
+    "Parameters": [
+      {
+        "Key": "X",
+        "Value": "6BB6B6B6",
+        "DataType": "ByteArray"
+      },
+	  {
+        "Key": "M",
+        "Value": "49949494",
+        "DataType": "ByteArray"
+      }
+    ]
   },
   {
     "EcuName": "Subaru_2EE2",