Library loader now scans libraries before loading them

IPA.Injector/Injector.cs

@@ -85,8 +85,7 @@ namespace IPA.Injector
 
                 GameVersionEarly.Load();
 
-                // load the anti-malware engine
-                _ = AntiMalwareEngine.Engine;
+                AntiMalwareEngine.Initialize();
 
                 Updates.InstallPendingUpdates();
 

IPA.Loader/AntiMalware/AntiMalwareEngine.cs

@@ -1,6 +1,7 @@
 #nullable enable
 using IPA.Config;
 using IPA.Logging;
+using System;
 
 namespace IPA.AntiMalware
 {
@@ -11,12 +12,21 @@ namespace IPA.AntiMalware
     /// <see cref="IAntiMalware"/>
     public static class AntiMalwareEngine
     {
+        private static IAntiMalware? engine;
+
         /// <summary>
         /// Gets the current Anti-Malware engine. 
         /// </summary>
-        public static IAntiMalware Engine { get; } = InitializeEngine();
+        public static IAntiMalware Engine => engine ?? throw new InvalidOperationException();
+
+        internal static bool IsInitialized => engine != null;
+
+        internal static void Initialize()
+        {
+            engine = CreateEngine();
+        }
 
-        private static IAntiMalware InitializeEngine()
+        private static IAntiMalware CreateEngine()
         {
             IAntiMalware? engine = null;
             if (SelfConfig.AntiMalware_.UseIfAvailable_)

IPA.Loader/Loader/LibLoader.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
@@ -9,6 +10,8 @@ using System.Linq;
 using IPA.Logging;
 using IPA.Utilities;
 using Mono.Cecil;
+using IPA.AntiMalware;
+using IPA.Config;
 #if NET3
 using Net3_Proxy;
 using Directory = Net3_Proxy.Directory;
@@ -50,7 +53,7 @@ namespace IPA.Loader
     {
         internal static string LibraryPath => Path.Combine(Environment.CurrentDirectory, "Libs");
         internal static string NativeLibraryPath => Path.Combine(LibraryPath, "Native");
-        internal static Dictionary<string, string> FilenameLocations;
+        internal static Dictionary<string, string> FilenameLocations = null!;
 
         internal static void Configure()
         {
@@ -113,13 +116,13 @@ namespace IPA.Loader
             }
         }
 
-        public static Assembly AssemblyLibLoader(object source, ResolveEventArgs e)
+        public static Assembly? AssemblyLibLoader(object source, ResolveEventArgs e)
         {
             var asmName = new AssemblyName(e.Name);
             return LoadLibrary(asmName);
         }
 
-        internal static Assembly LoadLibrary(AssemblyName asmName)
+        internal static Assembly? LoadLibrary(AssemblyName asmName)
         {
             Log(Logger.Level.Debug, $"Resolving library {asmName}");
 
@@ -131,19 +134,13 @@ namespace IPA.Loader
             if (FilenameLocations.TryGetValue(testFile, out var path))
             {
                 Log(Logger.Level.Debug, $"Found file {testFile} as {path}");
-                if (File.Exists(path))
-                    return Assembly.LoadFrom(path);
-
-                Log(Logger.Level.Critical, $"but {path} no longer exists!");
+                return LoadSafe(path);
             }
             else if (FilenameLocations.TryGetValue(testFile = $"{asmName.Name}.{asmName.Version}.dll", out path))
             {
                 Log(Logger.Level.Debug, $"Found file {testFile} as {path}");
                 Log(Logger.Level.Warning, $"File {testFile} should be renamed to just {asmName.Name}.dll");
-                if (File.Exists(path))
-                    return Assembly.LoadFrom(path);
-
-                Log(Logger.Level.Critical, $"but {path} no longer exists!");
+                return LoadSafe(path);
             }
 
             Log(Logger.Level.Critical, $"No library {asmName} found");
@@ -151,7 +148,33 @@ namespace IPA.Loader
             return null;
         }
 
-        internal static void Log(Logger.Level lvl, string message)
+        private static Assembly? LoadSafe(string path)
+        {
+            if (!File.Exists(path))
+            {
+                Log(Logger.Level.Critical, $"{path} no longer exists!");
+                return null;
+            }
+
+            if (AntiMalwareEngine.IsInitialized)
+            {
+                var result = AntiMalwareEngine.Engine.ScanFile(new FileInfo(path));
+                if (result is ScanResult.Detected)
+                {
+                    Log(Logger.Level.Error, $"Scan of '{path}' found malware; not loading");
+                    return null;
+                }
+                if (!SelfConfig.AntiMalware_.RunPartialThreatCode_ && result is not ScanResult.KnownSafe and not ScanResult.NotDetected)
+                {
+                    Log(Logger.Level.Error, $"Scan of '{path}' found partial threat; not loading. To load this, enable AntiMalware.RunPartialThreatCode in the config.");
+                    return null;
+                }
+            }
+
+            return Assembly.LoadFrom(path);
+        }
+
+    internal static void Log(Logger.Level lvl, string message)
         { // multiple proxy methods to delay loading of assemblies until it's done
             if (Logger.LogCreated)
                 AssemblyLibLoaderCallLogger(lvl, message);
@@ -172,7 +195,7 @@ namespace IPA.Loader
         private static void AssemblyLibLoaderCallLogger(Logger.Level lvl, Exception message) => Logger.libLoader.Log(lvl, message);
 
         // https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/file-system/how-to-iterate-through-a-directory-tree
-        private static IEnumerable<FileInfo> TraverseTree(string root, Func<string, bool> dirValidator = null)
+        private static IEnumerable<FileInfo> TraverseTree(string root, Func<string, bool>? dirValidator = null)
         {
             if (dirValidator == null) dirValidator = s => true;