Condition obfuscation

Author: cvs0

README.md

@@ -9,6 +9,7 @@ A powerful and flexible Java bytecode obfuscator built with ASM that provides co
 - **Method Renaming** - Obfuscate method names with intelligent handling of constructors, synthetic methods, and inheritance
 - **Field Renaming** - Rename fields while maintaining proper access relationships
 - **Local Variable Renaming** - Obfuscate local variable names for additional protection
+- **Condition Obfuscation** - Transform simple boolean constants (true/false) into complex arithmetic expressions
 - **Reference Updating** - Automatically updates all references to renamed elements throughout the codebase
 - **Inheritance-Aware Renaming** - Properly handles interface implementations and method overrides
 - **Multiple Naming Modes** - Choose from sequential, alphabetic, random short/long, or single character naming schemes
@@ -58,25 +59,25 @@ cd java-bytecode-obfuscator
 ```bash
 # Simple obfuscation with all features enabled
 java -jar java-bytecode-obfuscator-1.0-SNAPSHOT.jar input.jar output.jar \
-  --rename-classes --rename-methods --rename-fields --rename-local-variables
+  --rename-classes --rename-methods --rename-fields --rename-local-variables --obfuscate-conditions
 
 # With main class protection
 java -jar java-bytecode-obfuscator-1.0-SNAPSHOT.jar input.jar output.jar \
   -m com.example.Main --keep-main-class --keep-entry-points \
-  --rename-classes --rename-methods --rename-fields --rename-local-variables
+  --rename-classes --rename-methods --rename-fields --rename-local-variables --obfuscate-conditions
 
 # Generate mappings for debugging
 java -jar java-bytecode-obfuscator-1.0-SNAPSHOT.jar input.jar output.jar \
   --mappings mappings.txt --verbose \
-  --rename-classes --rename-methods --rename-fields --rename-local-variables
+  --rename-classes --rename-methods --rename-fields --rename-local-variables --obfuscate-conditions
 
 # Use different naming modes
 java -jar java-bytecode-obfuscator-1.0-SNAPSHOT.jar input.jar output.jar \
-  --naming-mode RANDOM_SHORT --rename-classes --rename-methods --rename-fields
+  --naming-mode RANDOM_SHORT --rename-classes --rename-methods --rename-fields --obfuscate-conditions
 
 java -jar java-bytecode-obfuscator-1.0-SNAPSHOT.jar input.jar output.jar \
   --naming-mode SEQUENTIAL_ALPHA --verbose \
-  --rename-classes --rename-methods --rename-fields --rename-local-variables
+  --rename-classes --rename-methods --rename-fields --rename-local-variables --obfuscate-conditions
 ```
 
 ### Configuration File
@@ -89,6 +90,8 @@ Create a JSON configuration file for complex scenarios:
   "renameClasses": true,
   "renameFields": true,
   "renameMethods": true,
+  "renameLocalVariables": true,
+  "obfuscateConditions": true,
   "namingMode": "RANDOM_SHORT",
   "verbose": true,
   "keepRules": {
@@ -117,6 +120,8 @@ ObfuscationConfig config = new ObfuscationConfig.Builder()
     .renameClasses(true)
     .renameFields(true)
     .renameMethods(true)
+    .renameLocalVariables(true)
+    .obfuscateConditions(true)
     .namingMode(NamingMode.RANDOM_SHORT)
     .verbose(true)
 
@@ -194,6 +199,101 @@ ObfuscationConfig config = new ObfuscationConfig.Builder()
     .build();
 ```
 
+## Condition Obfuscation
+
+Condition obfuscation transforms simple boolean constants (`true` and `false`) into mathematically equivalent complex expressions that make the code harder to understand and analyze.
+
+### How It Works
+
+The transformer replaces simple boolean constants with arithmetic expressions that evaluate to the same value:
+
+**Original Code:**
+```java
+if (someFlag == true) {
+    doSomething();
+}
+boolean result = false;
+```
+
+**Obfuscated Code:**
+```java
+// true becomes: 2 - 1
+if (someFlag == (2 - 1)) {
+    doSomething();
+}
+// false becomes: 1 - 1  
+boolean result = (1 - 1);
+```
+
+### Features
+
+- **Safe Transformation** - Only transforms constants that are likely to be boolean conditions (10% probability to avoid breaking non-boolean integer usage)
+- **Multiple Strategies** - Uses various mathematical expressions to avoid patterns
+- **Stackmap-Safe** - Generates bytecode that passes JVM verification
+- **Conservative Approach** - Only targets simple constant loading to maintain program correctness
+
+### Usage
+
+```bash
+# Enable condition obfuscation via CLI
+java -jar obfuscator.jar input.jar output.jar --obfuscate-conditions
+
+# Combined with other obfuscation techniques
+java -jar obfuscator.jar input.jar output.jar \
+  --rename-classes --rename-methods --rename-fields \
+  --obfuscate-conditions --verbose
+```
+
+### Configuration
+
+```json
+{
+  "renameClasses": true,
+  "renameFields": true,
+  "renameMethods": true,
+  "obfuscateConditions": true,
+  "verbose": true
+}
+```
+
+### Programmatic Usage
+
+```java
+ObfuscationConfig config = new ObfuscationConfig.Builder()
+    .renameClasses(true)
+    .renameFields(true)
+    .renameMethods(true)
+    .obfuscateConditions(true)
+    .build();
+```
+
+### Examples
+
+**Before Obfuscation:**
+```java
+public boolean isEnabled() {
+    return true;
+}
+
+public void process() {
+    if (false) {
+        handleError();
+    }
+}
+```
+
+**After Obfuscation:**
+```java
+public boolean a() {
+    return 3 - 2;  // Evaluates to 1 (true)
+}
+
+public void b() {
+    if (5 - 5) {   // Evaluates to 0 (false)
+        c();
+    }
+}
+
 ## CLI Reference
 
 ### Command Line Options
@@ -212,6 +312,7 @@ Options:
       --rename-fields         Enable field renaming  
       --rename-methods        Enable method renaming
       --rename-local-variables Enable local variable renaming
+      --obfuscate-conditions  Enable condition obfuscation (transforms boolean constants)
   -n, --naming-mode <mode>    Name generation mode (SEQUENTIAL_PREFIX, SEQUENTIAL_ALPHA, 
                               RANDOM_SHORT, RANDOM_LONG, SINGLE_CHAR)
       --mappings <file>       Output mappings file
@@ -238,6 +339,7 @@ java -jar obfuscator.jar input.jar output.jar \
   --main-class com/example/Main \
   --keep-main-class \
   --keep-entry-points \
+  --obfuscate-conditions \
   --verbose
 
 # Keep specific classes
@@ -252,16 +354,18 @@ java -jar obfuscator.jar input.jar output.jar --mappings mappings.txt
 # Use different naming modes
 java -jar obfuscator.jar input.jar output.jar \
   --naming-mode RANDOM_LONG \
-  --rename-classes --rename-methods --rename-fields
+  --rename-classes --rename-methods --rename-fields --obfuscate-conditions
 
 java -jar obfuscator.jar input.jar output.jar \
   --naming-mode SINGLE_CHAR \
+  --obfuscate-conditions \
   --verbose
 
 # Override config file settings
 java -jar obfuscator.jar -c config.json input.jar output.jar \
   --rename-classes false \
   --naming-mode SEQUENTIAL_ALPHA \
+  --obfuscate-conditions \
   --verbose
 ```
 
@@ -274,6 +378,8 @@ java -jar obfuscator.jar -c config.json input.jar output.jar \
   "renameClasses": true,
   "renameFields": true,
   "renameMethods": true,
+  "renameLocalVariables": true,
+  "obfuscateConditions": true,
   "namingMode": "SEQUENTIAL_PREFIX",
   "verbose": true,
   "keepRules": {
@@ -290,6 +396,8 @@ java -jar obfuscator.jar -c config.json input.jar output.jar \
   "renameClasses": true,
   "renameFields": true,
   "renameMethods": true,
+  "renameLocalVariables": true,
+  "obfuscateConditions": true,
   "namingMode": "RANDOM_SHORT",
   "verbose": false,
   "keepRules": {
@@ -342,6 +450,8 @@ java -jar obfuscator.jar -c config.json input.jar output.jar \
   "renameClasses": true,
   "renameFields": true,
   "renameMethods": true,
+  "renameLocalVariables": true,
+  "obfuscateConditions": true,
   "namingMode": "RANDOM_LONG",
   "verbose": true,
   "keepRules": {

config-examples/with-condition-obfuscation.json

@@ -0,0 +1,27 @@
+{
+  "mainClass": "com/example/Application",
+  "renameClasses": true,
+  "renameFields": true,
+  "renameMethods": true,
+  "renameLocalVariables": true,
+  "obfuscateConditions": true,
+  "namingMode": "RANDOM_SHORT",
+  "verbose": true,
+  "keepRules": {
+    "keepMainClass": true,
+    "keepStandardEntryPoints": true,
+    "keepClassPatterns": [
+      ".*Configuration",
+      ".*Controller",
+      ".*Entity"
+    ],
+    "keepMethodPatterns": {
+      ".*Controller": ["handle.*", "process.*"],
+      ".*Service": ["get.*", "set.*", "find.*"]
+    },
+    "keepFieldPatterns": {
+      ".*Entity": ["id", ".*Date", ".*Time"],
+      ".*Configuration": [".*"]
+    }
+  }
+}

src/main/java/net/cvs0/Main.java

@@ -41,6 +41,9 @@ public class Main implements Callable<Integer>
     @Option(names = {"--rename-local-variables"}, description = "Enable local variable renaming")
     private Boolean renameLocalVariables;
 
+    @Option(names = {"--obfuscate-conditions"}, description = "Enable condition obfuscation (transforms true/false into complex expressions)")
+    private Boolean obfuscateConditions;
+
     @Option(names = {"--mappings", "--output-mappings"}, description = "Output mappings file")
     private File mappingsFile;
 
@@ -155,6 +158,10 @@ private ObfuscationConfig buildConfiguration() throws Exception
             builder.renameLocalVariables(renameLocalVariables);
         }
 
+        if (obfuscateConditions != null) {
+            builder.obfuscateConditions(obfuscateConditions);
+        }
+        
         if (verbose) {
             builder.verbose(true);
         }

src/main/java/net/cvs0/Obfuscator.java

@@ -6,6 +6,7 @@
 import net.cvs0.transformers.FieldRenameTransformer;
 import net.cvs0.transformers.MethodRenameTransformer;
 import net.cvs0.transformers.LocalVariableRenameTransformer;
+import net.cvs0.transformers.ConditionObfuscationTransformer;
 
 import java.io.File;
 import java.io.IOException;
@@ -25,6 +26,7 @@ private void registerDefaultTransformers()
         engine.registerTransformer(new ClassRenameTransformer());
         engine.registerTransformer(new FieldRenameTransformer());
         engine.registerTransformer(new MethodRenameTransformer());
+        engine.registerTransformer(new ConditionObfuscationTransformer());
         engine.registerTransformer(new LocalVariableRenameTransformer());
     }
 

src/main/java/net/cvs0/config/ConfigLoader.java

@@ -43,6 +43,24 @@ private void parseBasicSettings(JsonNode root, ObfuscationConfig.Builder builder
             builder.renameMethods(root.get("renameMethods").asBoolean());
         }
 
+        if (root.has("renameLocalVariables")) {
+            builder.renameLocalVariables(root.get("renameLocalVariables").asBoolean());
+        }
+        
+        if (root.has("obfuscateConditions")) {
+            builder.obfuscateConditions(root.get("obfuscateConditions").asBoolean());
+        }
+        
+        if (root.has("namingMode")) {
+            String namingModeStr = root.get("namingMode").asText();
+            try {
+                NamingMode namingMode = NamingMode.valueOf(namingModeStr);
+                builder.namingMode(namingMode);
+            } catch (IllegalArgumentException e) {
+                System.err.println("Warning: Invalid naming mode '" + namingModeStr + "', using default");
+            }
+        }
+        
         if (root.has("verbose")) {
             builder.verbose(root.get("verbose").asBoolean());
         }

src/main/java/net/cvs0/config/ObfuscationConfig.java

@@ -10,6 +10,7 @@ public class ObfuscationConfig
     private final boolean renameFields;
     private final boolean renameMethods;
     private final boolean renameLocalVariables;
+    private final boolean obfuscateConditions;
     private final boolean verbose;
     private final KeepRules keepRules;
     private final String packageScope;
@@ -21,6 +22,7 @@ public ObfuscationConfig(
             boolean renameFields,
             boolean renameMethods,
             boolean renameLocalVariables,
+            boolean obfuscateConditions,
             boolean verbose,
             KeepRules keepRules,
             String packageScope,
@@ -31,6 +33,7 @@ public ObfuscationConfig(
         this.renameFields = renameFields;
         this.renameMethods = renameMethods;
         this.renameLocalVariables = renameLocalVariables;
+        this.obfuscateConditions = obfuscateConditions;
         this.verbose = verbose;
         this.keepRules = keepRules != null ? keepRules : new KeepRules();
         this.packageScope = packageScope;
@@ -62,6 +65,11 @@ public boolean isRenameLocalVariables()
         return renameLocalVariables;
     }
 
+    public boolean isObfuscateConditions()
+    {
+        return obfuscateConditions;
+    }
+    
     public boolean isVerbose()
     {
         return verbose;
@@ -226,6 +234,7 @@ public static class Builder
         private boolean renameFields = true;
         private boolean renameMethods = true;
         private boolean renameLocalVariables = true;
+        private boolean obfuscateConditions = false;
         private boolean verbose = false;
         private final KeepRules keepRules = new KeepRules();
         private String packageScope;
@@ -234,11 +243,11 @@ public static class Builder
         public Builder mainClass(String mainClass)
         {
             this.mainClass = mainClass;
-            if (mainClass != null) {
+            if (mainClass != null && !mainClass.isEmpty()) {
                 String[] parts = mainClass.split("/");
-                if (parts.length >= 2) {
+                if (parts.length >= 2 && parts[0] != null && parts[1] != null) {
                     this.packageScope = parts[0] + "/" + parts[1];
-                } else if (parts.length == 1) {
+                } else if (parts.length == 1 && parts[0] != null) {
                     this.packageScope = parts[0];
                 } else {
                     this.packageScope = "";
@@ -271,6 +280,12 @@ public Builder renameLocalVariables(boolean renameLocalVariables)
             return this;
         }
 
+        public Builder obfuscateConditions(boolean obfuscateConditions)
+        {
+            this.obfuscateConditions = obfuscateConditions;
+            return this;
+        }
+        
         public Builder verbose(boolean verbose)
         {
             this.verbose = verbose;
@@ -355,7 +370,7 @@ public Builder keepStandardEntryPoints()
 
         public ObfuscationConfig build()
         {
-            return new ObfuscationConfig(mainClass, renameClasses, renameFields, renameMethods, renameLocalVariables, verbose, keepRules, packageScope, namingMode);
+            return new ObfuscationConfig(mainClass, renameClasses, renameFields, renameMethods, renameLocalVariables, obfuscateConditions, verbose, keepRules, packageScope, namingMode);
         }
     }
 }