MED 17 , EDC 17 EEPROM CHECKSUM

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kuebk:
Figured out myself what I was doing wrong, nevermind.

carservice:
HI
 crypted CS, PIN, MAC algorithm ，You succeeded in the calculation？I did a lot of research, but it didn't work out.

carservice:
Quote from: H2Deetoo on July 10, 2018, 07:19:23 AM

You can deduct the XOR with known values.
It is calculated from unique ID from EDC17 from OTP area, so the XOR result is unique for each EDC.

I found the immo data in EEPROM and the encrypted bytes in the OTP area, but failed to compute.

sandor1987:
somebody found out how to calculate cs pin mac etc?

Matrosek:
Quote from: Ionut on September 21, 2017, 02:01:17 PM

Hi all, i`ve tried every possible combination and nothing seems to work....
For example this block
Code:

08 00 EB 04 94 53 00 00 FF B8 71 E0 EA 30 D0 E4 B1 8E 05 E4 35 AF 3E F2 8E 6A 09 9C A7 EF 80 E7 FC AE AE 56 AA 80 01 00 57 41 55 5A 5A 5A 38 54 37 42 41 30 39 37 36 36 31 48 EF E0 24 BA 6C 05 30 02 B6 6C 7D 43 97 A4 F9 B1 EF BF F7 74 FB 67 52 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 C1 4E 00 00 56 8D F6 1C
Tried with CRC32 with poly 0xEDB88320, initial value 0xC14E0000, bytes from 8 to 7F (119 bytes) and result is D7A854D and it should be 56 8D F6 1C.
With initial value just first 2 bytes (0xC14E), result is F219CCDD, with fist 2 bytes reversed, result is AA79A104 and with initial value 0x4EC10000 (each 2 bytes reversed) result is 418F9500

Here is the C# code used for CRC32:
Code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace FwpCrc
{
    class CRC32
    {
        uint[] table;

        public uint ComputeChecksum(byte[] bytes, uint initialValue) {
            uint crc = initialValue;
        //  uint crc = 0xffffffff;
            for(int i = 0; i < bytes.Length; ++i) {
                byte index = (byte)(((crc) & 0xff) ^ bytes[i]);
                crc = (uint)((crc >> 8) ^ table[index]);
            }
            return ~crc;
        }

        public CRC32() {
            uint poly = 0xEDB88320;
            table = new uint[256];
            uint temp = 0;
            for(uint i = 0; i < table.Length; ++i) {
                temp = i;
                for(int j = 8; j > 0; --j) {
                    if((temp & 1) == 1) {
                        temp = (uint)((temp >> 1) ^ poly);
                    }else {
                        temp >>= 1;
                    }
                }
                table[i] = temp;
            }
        }
    }
}
I`m doing something wrong?


Hi all, I used code from post #39 and CRC from post #38, but I get wrong CRCsum. What I'm doing wrong?
My code:
Code:

using System;
using System.IO;
using System.Text;

namespace TricoreCRC32Calculator
{
    public class Program
    {
        public static void Main(string[] args)
        {
            while (true)
            {
                Console.WriteLine("\nCRC-Calculator...");
                Console.Write("File name: ");
                TricoreCRC32 CRC = new TricoreCRC32(Console.ReadLine());
                Console.WriteLine(CRC);
                uint initValue = 0x00000036;
                uint result = CRC.ComputeChecksum(initValue);
                Console.WriteLine("{0:X}", result);
                Console.Write("Continue or exit: ");
                if (Console.ReadLine() == "exit") break;
            }
        }
    }

    public class TricoreCRC32
    {
        private byte[] block = new byte[124];
        private uint[] table = new uint[256];


        private async void ReadBlock(string nameFile)
        {
            try
            {
                await new FileStream(nameFile, FileMode.Open).ReadAsync(block, 0, block.Length);
            }
            catch (FileNotFoundException)
            {
                Console.WriteLine("Not found file!");
            }
            catch (IOException)
            {
                Console.WriteLine("Another error!");
            }
        }

        public TricoreCRC32(string nameFile)
        {
            ReadBlock(nameFile);
        }

        public override string ToString()
        {
            StringBuilder block = new StringBuilder();
            for (int i = 0; i < 124; i++)
            {
                block.AppendFormat("{0:X}", this.block[i]);
                block.Append(' ');
            }
            return "Block: " + block;
        }

        public uint ComputeChecksum(uint initialValue)
        {
            CreateTable();
            uint crc = initialValue;
            //  uint crc = 0xffffffff;
            for (int i = 0; i < block.Length; ++i)
            {
                byte index = (byte)(((crc) & 0xff) ^ block[i]);
                crc = (uint)((crc >> 8) ^ table[index]);
            }
            return ~crc;
        }

        public uint[] CreateTable()
        {
            table = new uint[256];
            uint poly = 0xEDB88320;
            uint temp;
            for (uint i = 0; i < table.Length; ++i)
            {
                temp = i;
                for (int j = 8; j > 0; --j)
                {
                    if ((temp & 1) == 1)
                    {
                        temp = (uint)((temp >> 1) ^ poly);
                    }
                    else
                    {
                        temp >>= 1;
                    }
                }
                table[i] = temp;
            }
            return table;
        }
    }
}


Right CRC is F2 78, but I get 42 0D 0B 00. Block file in attachments.

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