AEWFFSaveEncDec

AEWFFSaveEncDec.cs

///////////////////////////////////////////////////////
// AEWFFSaveEncDec by Nenkai
// Requires: .NET 10.0
// Extract raw/raw sub data from sav files (i.e UGCWrestler_2.sav) first, using GvasViewer or something else
// Usage: dotnet run AEWFFEncDec.cs <input file path, encrypted or decrypted>
// The decrypted output is another save file
///////////////////////////////////////////////////////

// SPDX-FileCopyrightText: Copyright 2026 Nenkai
// SPDX-License-Identifier: MIT

using System.Buffers.Binary;
using System.Security.Cryptography;
using System.Text;

Console.WriteLine("-----------------------------------------");
Console.WriteLine($"- AEWFFSaveEncDec by Nenkai");
Console.WriteLine("-----------------------------------------");
Console.WriteLine("- https://github.com/Nenkai");
Console.WriteLine("- https://twitter.com/Nenkaai");
Console.WriteLine("-----------------------------------------");
Console.WriteLine("");

if (args.Length == 0 || !File.Exists(args[0]))
{
    Console.WriteLine("Usage: <input file path, encrypted or decrypted>");
    return;
}

Console.WriteLine($"Input: {args[0]}");

try
{
    byte[] input = File.ReadAllBytes(args[0]);
    string fullPath = Path.GetFullPath(args[0]);

    uint length = BinaryPrimitives.ReadUInt32LittleEndian(input);

    // ELGameServerParam->SaveDataEncryptKey
    // https://github.com/peek6/AewFFCustomUProj/blob/2eef5e9c86cb1982eb3ea57ce0a6b43729a9e2a7/Source/ABP_200508/Private/ELGameServerParam.cpp#L25
    const string KeyStr = "hSmG!+h2Sp.NZ*b~,X.BEy,5Kr3++UFS9.iX7";
    byte[] Key = Encoding.UTF8.GetBytes(KeyStr).AsSpan(0, 32).ToArray();

    using Aes aes = Aes.Create();
    aes.Key = Key;

    if (input.Length >= 4 && length == input.Length - 4)
    {
        Console.WriteLine("Assuming encrypted, decrypting");

        Span<byte> encrypted = input.AsSpan(0x04);
        aes.DecryptEcb(encrypted, encrypted, PaddingMode.None);

        string newPath = Path.Combine(Path.GetDirectoryName(fullPath), $"{Path.GetFileNameWithoutExtension(fullPath)}_dec" + Path.GetExtension(fullPath));
        File.WriteAllBytes(newPath, encrypted);
        Console.WriteLine($"Decrypted to {newPath}");
    }
    else
    {
        Console.WriteLine("Assuming decrypted, encrypting");

        aes.EncryptEcb(input, input, PaddingMode.None);
        byte[] newBuffer = new byte[4 + input.Length];
        BinaryPrimitives.WriteInt32LittleEndian(newBuffer, input.Length);
        input.AsSpan().CopyTo(newBuffer.AsSpan(0x04));

        string newPath = Path.Combine(Path.GetDirectoryName(fullPath), $"{Path.GetFileNameWithoutExtension(fullPath)}_enc" + Path.GetExtension(fullPath));
        File.WriteAllBytes(newPath, newBuffer);

        Console.WriteLine($"Encrypted to {newPath}");
    }
}
catch (Exception e)
{
    Console.WriteLine($"Errored: {e.Message}");
}