Kayori_Medusa.net/Core/Server/Program.cs

using KbinXml.Net;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Server;
using Server.Entities;
using Server.Extensions;
using Server.Middlewares;
using Server.Request;
using Server.Services;
using Server.Utils;
using System.Security.Cryptography;
using System.Text;
using System.Xml.Linq;

var key =
    Convert.FromHexString("00000000000069D74627D985EE2187161570D08D93B12455035B6DF0D8205DF5");

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.

builder.Services.AddHandlers();

builder.Services.AddDbContext<AppDbContext>(options => options.UseSqlite("Data Source=Medusa.db;"));

builder.Services.AddIdentityCore<User>(config =>
{
    config.Password.RequiredLength = 8;
    config.SignIn.RequireConfirmedEmail = true;
    config.Lockout.AllowedForNewUsers = true;
}).AddEntityFrameworkStores<AppDbContext>();

builder.Services.AddTransient<ICardService, CardService>();
builder.Services.AddSingleton<ISessionService, SessionService>();

var app = builder.Build();

app.UseDefaultFiles();
app.UseStaticFiles();

// Configure the HTTP request pipeline.

//app.UseHttpsRedirection();
app.UseMiddleware<BodyParsingMiddleware>();
app.UseHandlers();

var eamuseGroup = app.MapGroup("eamuse");

eamuseGroup.MapPost("/{model}/{module}/{method}", (string model, string module, string method,
    [FromServices] IHttpContextAccessor httpContextAccessor) =>
{

});

eamuseGroup.MapPost("/{m}", async (string m, [FromQuery] string model, [FromQuery] string? module, [FromQuery] string? method, [FromQuery] string? f,
    HttpContext httpContext, [FromServices] ILogger<Program> logger, [FromServices] IHandlerService handlerService) =>
{
    // Enable buffering to allow multiple reads of the request body
    httpContext.Request.EnableBuffering();

    // The body is 932 encoded xml
    using var reader = new StreamReader(httpContext.Request.Body, Encoding.GetEncoding(932), false, 1024, true);
    var body = await reader.ReadToEndAsync();

    httpContext.Request.Body.Position = 0;

    bool compress = httpContext.Request.Headers["X-Compress"].ToString().Contains("lz77");
    bool encrypt = httpContext.Request.Headers["X-Eamuse-Info"].FirstOrDefault() is not null;

    var amusementRequest = new AmusementRequest() { Model = model, Module = module ?? "", Method = method ?? "" };

    if(!string.IsNullOrEmpty(f))
    {
        var fParts = f.Split('.');
        amusementRequest.Module = fParts[0];
        amusementRequest.Method = fParts[1];
    }

    logger.LogInformation("Handling {Module} {Method}", amusementRequest.Module, amusementRequest.Method);

    var document = new XDocument();

    if (!string.IsNullOrEmpty(body))
        document = XDocument.Parse(body);

    var responseXml = await handlerService.Handle(amusementRequest.Model, amusementRequest.Module, amusementRequest.Method, document);

    var encoding = httpContext.Items["Encoding"]?.ToString() ?? "ShiftJIS";

    switch(encoding)
    {
        case "shift_jis":
            encoding = "ShiftJIS";
            break;
        case "us-ascii":
            encoding = "ASCII";
            break;
        case "utf-8":
            encoding = "UTF8";
            break;
        case "euc-jp":
            encoding = "EUC_JP";
            break;
    }

    byte[] encodedBody = KbinConverter.Write(responseXml, (KnownEncodings)Enum.Parse(typeof(KnownEncodings), encoding, true));

    if(compress)
    {
        encodedBody = LZ77.CompressEmpty(encodedBody);
    }

    if(encrypt)
    {
        string[] originalInfo = httpContext.Request.Headers["X-Eamuse-Info"].FirstOrDefault()?.Split('-') ?? [];
        byte[] part = Convert.FromHexString((originalInfo[1] + originalInfo[2]));
        for(int i = 0; i < 6; i++)
            key[i] = part[i];
        var rc4Key = MD5.HashData(key);
        encodedBody = RC4.Encrypt(rc4Key, encodedBody);

        httpContext.Response.Headers.Append("X-Eamuse-Info", string.Join('-', originalInfo));
    }

    return TypedResults.Bytes(encodedBody, "application/octet-stream");
});

eamuseGroup.MapPost("/", async ([FromQuery] string model, [FromQuery] string? module, [FromQuery] string? method, [FromQuery] string? f,
    HttpContext httpContext, [FromServices] ILogger<Program> logger, [FromServices] IHandlerService handlerService) =>
{
    // Enable buffering to allow multiple reads of the request body
    httpContext.Request.EnableBuffering();
    var body = "";
    // The body is 932 encoded xml
    if(httpContext.Request.Body.Length != 0)
    {
        using var reader = new StreamReader(httpContext.Request.Body, Encoding.GetEncoding(932), false, 1024, true);
        body = await reader.ReadToEndAsync();
    }

    httpContext.Request.Body.Position = 0;

    bool compress = httpContext.Request.Headers["X-Compress"].ToString().Contains("lz77");
    bool encrypt = httpContext.Request.Headers["X-Eamuse-Info"].FirstOrDefault() is not null;

    var amusementRequest = new AmusementRequest() { Model = model, Module = module ?? "", Method = method ?? ""};

    if (!string.IsNullOrEmpty(f))
    {
        var fParts = f.Split('.');
        amusementRequest.Module = fParts[0];
        amusementRequest.Method = fParts[1];
    }

    logger.LogInformation("Handling {Module} {Method}", amusementRequest.Module, amusementRequest.Method);

    var document = new XDocument();
    
    if(!string.IsNullOrEmpty(body))
        document = XDocument.Parse(body);

    var responseXml = await handlerService.Handle(amusementRequest.Model, amusementRequest.Module, amusementRequest.Method, document);

    var encoding = httpContext.Items["Encoding"]?.ToString() ?? "ShiftJIS";

    switch(encoding)
    {
        case "shift_jis":
            encoding = "ShiftJIS";
            break;
        case "us-ascii":
            encoding = "ASCII";
            break;
        case "utf-8":
            encoding = "UTF8";
            break;
        case "euc-jp":
            encoding = "EUC_JP";
            break;
    }

    var encodedBody = KbinConverter.Write(responseXml, (KnownEncodings)Enum.Parse(typeof(KnownEncodings), encoding, true));

    if(compress)
    {
        encodedBody = LZ77.CompressEmpty(encodedBody);
    }

    if (!encrypt) return TypedResults.Bytes(encodedBody, "application/octet-stream");
    var originalInfo = httpContext.Request.Headers["X-Eamuse-Info"].FirstOrDefault()?.Split('-') ?? [];
    var part = Convert.FromHexString((originalInfo[1] + originalInfo[2]));
    for(var i = 0; i < 6; i++)
        key[i] = part[i];
    var rc4Key = MD5.HashData(key);
    encodedBody = RC4.Encrypt(rc4Key, encodedBody);

    httpContext.Response.Headers.Append("X-Eamuse-Info", string.Join('-', originalInfo));

    return TypedResults.Bytes(encodedBody, "application/octet-stream");
});

app.MapFallbackToFile("/index.html");

await using var scope = app.Services.CreateAsyncScope();

var appDbContext = scope.ServiceProvider.GetRequiredService<AppDbContext>();
await appDbContext.Database.MigrateAsync();

app.Run();