Add preserveTokensAndTypes()

de4dot.code/deobfuscators/DeobfuscatorBase.cs

@@ -51,6 +51,8 @@ namespace de4dot.code.deobfuscators {
 		MethodCallRemover methodCallRemover = new MethodCallRemover();
 		byte[] moduleBytes;
 		protected InitializedDataCreator initializedDataCreator;
+		bool keepTypes;
+		MetaDataFlags? mdFlags;
 
 		protected byte[] ModuleBytes {
 			get { return moduleBytes; }
@@ -78,7 +80,7 @@ namespace de4dot.code.deobfuscators {
 		public DecrypterType DefaultDecrypterType { get; set; }
 
 		public virtual MetaDataFlags MetaDataFlags {
-			get { return Operations.MetaDataFlags; }
+			get { return mdFlags ?? Operations.MetaDataFlags; }
 		}
 
 		public abstract string Type { get; }
@@ -89,8 +91,9 @@ namespace de4dot.code.deobfuscators {
 			get { return false; }
 		}
 
-		protected virtual bool KeepTypes {
-			get { return false; }
+		protected bool KeepTypes {
+			get { return keepTypes; }
+			set { keepTypes = value; }
 		}
 
 		protected bool CanRemoveTypes {
@@ -129,6 +132,15 @@ namespace de4dot.code.deobfuscators {
 			initializedDataCreator = new InitializedDataCreator(module);
 		}
 
+		protected void preserveTokensAndTypes() {
+			keepTypes = true;
+			mdFlags = Operations.MetaDataFlags;
+			mdFlags |= MetaDataFlags.PreserveRids |
+						MetaDataFlags.PreserveUSOffsets |
+						MetaDataFlags.PreserveBlobOffsets |
+						MetaDataFlags.PreserveExtraSignatureData;
+		}
+
 		protected virtual bool checkValidName(string name) {
 			return optionsBase.ValidNameRegex.isMatch(name);
 		}

de4dot.code/deobfuscators/Unknown/Deobfuscator.cs

@@ -63,12 +63,9 @@ namespace de4dot.code.deobfuscators.Unknown {
 			get { return obfuscatorName ?? "Unknown Obfuscator"; }
 		}
 
-		protected override bool KeepTypes {
-			get { return true; }
-		}
-
 		internal Deobfuscator(Options options)
 			: base(options) {
+			KeepTypes = true;
 		}
 
 		void setName(string name) {