Match method signatures in reobfuscation

NuclearPowered · Feb 15, 2021 · 81696bc · 81696bc
1 parent 1b4c68d
commit 81696bc
Show file tree

Hide file tree

Showing 3 changed files with 25 additions and 5 deletions.
diff --git a/Reactor.OxygenFilter.MSBuild/Reactor.OxygenFilter.MSBuild.csproj b/Reactor.OxygenFilter.MSBuild/Reactor.OxygenFilter.MSBuild.csproj
@@ -4,7 +4,7 @@
         <LangVersion>latest</LangVersion>
         <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
 
-        <Version>0.2.5</Version>
+        <Version>0.2.6</Version>
         <RepositoryType>git</RepositoryType>
         <RepositoryUrl>https://github.com/NuclearPowered/Reactor.OxygenFilter</RepositoryUrl>
         <PackageLicenseExpression>LGPL-3.0-or-later</PackageLicenseExpression>

diff --git a/Reactor.OxygenFilter.MSBuild/Reobfuscate.cs b/Reactor.OxygenFilter.MSBuild/Reobfuscate.cs
@@ -229,7 +229,8 @@ void ReobfuscateType(TypeReference t)
                             }
 
                             // get same method from obfuscated assembly
-                            MethodReference definition = typeDefinition.GetMethods().Single(x => x.Name == obfuscated);
+                            var signature = deobfuscatedCall.GetSignature(t => GetObfuscated(t) ?? t.FullName);
+                            MethodReference definition = typeDefinition.GetMethods().Single(x => x.Name == obfuscated && x.GetSignature() == signature);
 
                             // obfuscate generics
                             if (deobfuscatedCallReference is GenericInstanceMethod generic)

diff --git a/Reactor.OxygenFilter/Extensions.cs b/Reactor.OxygenFilter/Extensions.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Linq;
 using System.Text;
 using Mono.Cecil;
@@ -11,11 +12,29 @@ public static bool IsObfuscated(this string text)
             return text.Length == 11 && text.All(char.IsUpper);
         }
 
-        public static string GetSignature(this MethodDefinition methodDefinition)
+        public static string GetSignature(this MethodDefinition methodDefinition, Func<TypeDefinition, string> map = null)
         {
+            map ??= provider => provider.FullName;
+
+            string MapIfResolved(TypeReference typeReference)
+            {
+                TypeDefinition resolved = null;
+
+                try
+                {
+                    resolved = typeReference.Resolve();
+                }
+                catch
+                {
+                    // ignored
+                }
+
+                return resolved != null ? map(resolved) : typeReference.FullName;
+            }
+
             var sb = new StringBuilder();
 
-            sb.Append(methodDefinition.ReturnType.FullName);
+            sb.Append(MapIfResolved(methodDefinition.ReturnType));
             sb.Append(" ");
 
             sb.Append("(");
@@ -31,7 +50,7 @@ public static string GetSignature(this MethodDefinition methodDefinition)
                     if (parameterType is SentinelType)
                         sb.Append("...,");
 
-                    sb.Append(parameterType.FullName);
+                    sb.Append(MapIfResolved(parameterType));
                 }
             }