krisives/d2s-format

Diablo II Save File Format (.d2s format)

d2s-format's Issues

[Suggestion]: My C++ version of the checksum algorithm should it help anyone

This is ready to be built in VS2022.

#define _CRT_SECURE_NO_DEPRECATE

#include <iostream>
#include <stdio.h>
#include<string>

using namespace std;

char** argv = NULL;

void main(int argc, char** argv)
{
	if (argv[1] == NULL) {
		cout << "\n\n\tNo .d2s file specified. \n\n\tUsage: d2scs.exe char.d2s\n\n" << endl;
		return;
	}

	FILE* charFile;
	charFile = fopen(argv[1], "r+b");

	// zero out the previous checksum
	char zero[4] = { 0 };
	fseek(charFile, 12, SEEK_SET);
	fwrite(zero, sizeof(char),sizeof(zero), charFile);
	fflush(charFile);
	fseek(charFile, 0, SEEK_SET);

	unsigned char saveFileData[16];
	unsigned long counter = 0;
	unsigned int uSum = 0;

	int n;
	int uVar = 0;
	int byte;

	while ((n = fread(saveFileData, sizeof(char), 16, charFile)) > 0) {
		int i;
		for (i = 0; i < n; i++) {
			// Current byte in charFile		
			byte = (unsigned)saveFileData[i];

			//SAME as uSum  line, just to double check if both produce the same checksum
			if (uVar < 0)
				byte++;
			uVar = byte + uVar * 2;

			//SAME as above block, just to double check if both produce the same checksum
			uSum = ((uSum << 1) | (uSum >> 31)) + (unsigned)saveFileData[i];
		}
		counter += 16;
	}
	
	unsigned long r_uVar = _byteswap_ulong(uVar);
	unsigned long r_uSum = _byteswap_ulong(uSum);

	// write new checksum
	fseek(charFile, 12, SEEK_SET);
	fwrite(&uVar, sizeof(uVar), 1, charFile);
	fflush(charFile);
	fseek(charFile, 0, SEEK_SET);

	printf("\n\n\t%08x checksum written to %s\n\n", r_uVar, argv[1]);

	fclose(charFile);
}

Bytes 16-20 may be Active Weapon

according to http://www.coreyh.org/diablo-2-files/documentation/d2s_save_file_format_1.13d.html, the value of bytes 16-20 is the number of the currently active weapon set. Unfortunately, I have no means of checking that right now :)

Implementation of checksum calculation in javascript

const fs = require("fs");
const path = require("path");
const file = path.join(process.cwd(), "path_to_save.d2s");

function calculateSum(data) {
  let sum = 0;
  for (let i = 0; i < data.length; i++) {
    let ch = data[i];
    if (i >= 12 && i < 16) {
      ch = 0;
    }
    ch += sum < 0;
    sum = (sum << 1) + ch;
  }

  return sum;
}

function littleToBigEndian(number) {
  return new DataView(
    Int32Array.of(
      new DataView(Int32Array.of(number).buffer).getUint32(0, true)
    ).buffer
  );
}

function ashex(buffer) {
  return buffer.getUint32(0, false).toString(16);
}

async function readSafeFile() {
  return await new Promise((resolve, reject) => {
    fs.readFile(file, (err, data) => {
      if (err) return reject(err);
      return resolve(data);
    });
  });
}

async function writeCheckSumToSafeFile(data) {
  return await new Promise((resolve, reject) => {
    fs.writeFile(file, data, err => {
      if (err) reject(err);
      resolve();
    });
  });
}

readSafeFile().then(data => {
  const sum = calculateSum(data);
  const bufferSum = littleToBigEndian(sum);
  const hex = ashex(bufferSum);
  const newData = data;
  for (let i = 0; i < 4; i++) {
    newData[12 + i] = bufferSum.getInt8(i);
  }
  writeCheckSumToSafeFile(newData).then(() => console.log(hex));
});

XP offset for 1.12 d2s

Xp is stored at offset 802 as 4 byte little endian unsigned int multiplied by 2.

Eg, if your in-game xp is 79 689 129, then at offset 802 you'll see:
79 689 129 * 2 = 159 378 258 => hex => 52 EB 7F 09

So if you set xp bytes to zeros 00 00 00 00, you have to update char level (offset:43, 1 byte) with 01 and so on.

Can show nodejs code how to reset char level to 1.

checksum code in C language doesn't work well

should be add :

if checksum <0 ch = data[i]+1 # add this line
checksum = checksum<<1 + che

Fix formatting

Something changed in Markdown now it doesnt render the tables

[Suggestion]: My PHP version of the checksum algorithm should it help anyone

Hi. Thanks for the great resource. Please add my version of the checksum algorithm in PHP should this help anyone.

<?php
/*
  Diablo 2 D2S Save File Checksum Calculator 
  By Hash Borgir (https://www.psychedelicsdaily.com)
  @date 6/4/2022

 Checksum field is at byte 12. 
 Bytes 12/13/14/15 as a uint32. 
 Set this to 0. 
 After clearing the checksum field add up the values of all the bytes in the file and rotate the running total one bit to the left before adding the next byte.
*/

/**
 * @param string $hex
 * @return string
 */
function swapEndianness(string $hex) {
    return implode('', array_reverse(str_split($hex, 2)));
}

/**
 * Calculate D2S Checksum
 * @param $data
 * @return string
 */
function checksum($fileData) {
    $nSignature = 0;
    foreach ($fileData as $k => $byte) {
        if ($k == 12 || $k == 13 || $k == 14 || $k == 15)  { // skip bytes 12,13,14,15
            $byte = 0;
        }
        $nSignature = ((($nSignature << 1) | ($nSignature >> 31)) + $byte & 0xFFFFFFFF);
    }
    return swapEndianness(str_pad(dechex($nSignature), 8, 0, STR_PAD_LEFT));
}

$filename = "D:\Diablo II\MODS\ironman-dev\save\Sorc.d2s";
$fp = fopen($filename, "rb+");

fseek($fp, 12); // go to byte 12
fwrite($fp, pack('I', 0)); // clear the checksum field uInt32
$fileData = unpack('C*', file_get_contents($filename)); // open file and unpack

fseek($fp, 12); // go to byte 12
fwrite($fp, pack('H8', checksum($fileData))); // write new checksum
fclose($fp);

Check info from Corey H.

Hey!

http://coreyh.org/diablo-2-1.13d-code/

Plenty of code to help you with your d2s deconstruction.
adios.

Reset stat/skills at Akara is 0x1AB.

Version: 1.14d
Before resetting, offset 0x1AB was 2.
After resetting, it's 1.
Change it back to 2, the reset option reappears.