unreliablecode / Unity-AntiModLoader

using System;
using System.IO;
using UnityAntiModLoader.Models;

namespace UnityAntiModLoader.Detectors
{
    public static class BepInExDetector
    {
        // Known BepInEx directory structures
        private static readonly string[] s_KnownDirectories = new string[]
        {
            "BepInEx",
            "BepInEx/core",
            "BepInEx/plugins",
            "BepInEx/patchers",
            "BepInEx/config"
        };

        // Known BepInEx binaries and proxy DLLs
        private static readonly string[] s_KnownFiles = new string[]
        {
            "doorstop_config.ini",
            "winhttp.dll",
            "doorstop_version.txt",
            "BepInEx/core/BepInEx.dll",
            "BepInEx/core/BepInEx.Core.dll",
            "BepInEx/core/0Harmony.dll",
            "BepInEx/core/0Harmony20.dll",
            "BepInEx/core/Mono.Cecil.dll",
            "BepInEx/core/BepInEx.Preloader.dll",
            "BepInEx/LogOutput.log"
        };

        /// <summary>
        /// Scans the game directory for BepInEx mod loader artifacts.
        /// </summary>
        /// <param name="gameRootDirectory">Base path of the game executable.</param>
        /// <returns>ModDetectionResult with detected files and directories.</returns>
        public static ModDetectionResult Scan(string gameRootDirectory)
        {
            var result = new ModDetectionResult
            {
                FrameworkName = "BepInEx",
                DetectionTimestamp = DateTime.UtcNow
            };

            if (string.IsNullOrEmpty(gameRootDirectory) || !Directory.Exists(gameRootDirectory))
            {
                return result;
            }

            // 1. Check for known BepInEx directories
            foreach (string relDir in s_KnownDirectories)
            {
                string fullDirPath = Path.Combine(gameRootDirectory, relDir);
                try
                {
                    if (Directory.Exists(fullDirPath))
                    {
                        result.DetectedArtifacts.Add($"Directory: {relDir}");
                    }
                }
                catch
                {
                    // Ignore filesystem access exceptions
                }
            }

            // 2. Check for known BepInEx files & proxy loaders
            foreach (string relFile in s_KnownFiles)
            {
                string fullFilePath = Path.Combine(gameRootDirectory, relFile);
                try
                {
                    if (File.Exists(fullFilePath))
                    {
                        result.DetectedArtifacts.Add($"File: {relFile}");
                    }
                }
                catch
                {
                    // Ignore filesystem access exceptions
                }
            }

            // Evaluate severity
            if (result.DetectedArtifacts.Count > 0)
            {
                result.Severity = result.DetectedArtifacts.Count >= 2 ? DetectionSeverity.Critical : DetectionSeverity.High;
            }

            return result;
        }
    }
}