Encryptomatic Signature Algorithm

[Klaz0r]

Hey, I've been looking around, and I can't find the article the iron_forge or whoever released that talked about the halo 2 encryptomatic signature(unless it never even existed, but I think I can remember it). I'm basically looking for the algorithm to re-encrypt the mapfile, or the code in VB that would do it. I've been searching for a couple of days, but I just know that someone will search and find it in a couple of minutes, that's just my luck.

[zwull]

http://tf6.epgservers.net/downloads/h2whitepaper.rar

[xbox7887]

The checksum is generated by xoring everything from 0x800 to the eof.

[Ion]

The checksum is generated by xoring everything from 0x800 to the eof.

XORing with what?

[Prey]

You xor the first int32 with 0, then the result of that with the next int32 in thr map and so on until you reach the eof like xbox said.

[Ion]

Ok, so you xor the next read dword with the checksum.
Xoring with 0? XORing a value with 0 would be rather pointless. :p

[Prey]

Im not going to argue.

Code: Select all

            FileStream fs = new FileStream(map.path,
                FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);

            BinaryReader br = new BinaryReader(fs);
            BinaryWriter bw = new BinaryWriter(fs);

            int sig = 0;
            long length = br.BaseStream.Length;

            br.BaseStream.Position = 2048;

            for (long i = 2048; i < length; i += 4)
                sig ^= br.ReadInt32();

            br.BaseStream.Position = 720;
            bw.Write(sig);

            br.Close();
            bw.Close();

[OwnZ joO]

He's just saying xoring with 0 gets the same value you xor it with, so it's pointless.