Obfusc2

A code obfuscation tool for C/Minic programs that applies multiple transformation techniques to make source code harder to understand while preserving functionality.

Overview

Obfusc2 is a source-to-source transformation tool that takes C/Minic code as input and produces semantically equivalent but obfuscated code as output. The tool uses ANTLR4 for parsing and applies multiple obfuscation techniques in sequence.

Obfuscation Techniques

The project implements several obfuscation strategies:

1. Dead Code Insertion - Adds syntactically valid but unreachable or ineffective code to confuse readers
2. Variable Renaming - Replaces meaningful variable names with random or confusing identifiers
3. Expression Rewriting - Transforms simple expressions into more complex but equivalent expressions

Technology Stack

• Java 17 and Kotlin 1.9.22 for implementation
• ANTLR4 for parsing Minic language
• Maven for project management and building

Interactive CLI Usage

The tool features an interactive command-line interface:

java -jar obfusc2.jar

CLI Workflow

When you run the application, you'll be guided through the following steps:

1. A welcome header is displayed
2. You'll be prompted to enter the name of your mini-c code file
3. You can select which obfuscation technique(s) to apply:
   • Dead code insertion
   • Variable renaming
   • Expression rewriting
   • All techniques combined
4. The tool will process your file and save the obfuscated output
5. You can then choose to process another file or exit

Example Session

      _____ _      __           _____
      |  _  | |    / _|         /  __ \
      | | | | |__ | |_ _   _ ___| /  \/
      | | | | '_ \|  _| | | / __| |
      \ \_/ / |_) | | | |_| \__ \ \__/\
      \___/|_.__/|_|  \__,_|___/\____/


This is a simple CLI for obfuscating your mini-c code, so no one else can read it (except you of course!).

Now tell me, what is the name of your mini-c code?: input.c

What obfuscation method do you want to use?
1. Dead code
2. Variable renaming
3. Expression rewriting
4. All!
Input the number: 4

✓
 Doing heavy obfuscation work... Done!

Your obfuscated code is ready! Check your test folder.

What next?
1. Choose another file
2. Exit

Building from Source

# Clone the repository
git clone https://github.com/username/Obfusc2.git
cd Obfusc2

# Build with Maven
mvn clean package

# Run the application
java -jar target/Obfusc2-1.0-SNAPSHOT.jar

Example

Original code:

int factorial(int n) {
    if (n <= 1) {
        return 1;
    } else {
        return n * factorial(n - 1);
    }
}

Obfuscated code:

int a_5fc3(int x_e45) {
    int _d = 42;
    if (_d > 100) { printf("unreachable"); }
    if ((x_e45 + 0) <= (1 * 1)) {
        if (1) { return 1; }
    } else {
        int _tmp = 0;
        while (_tmp < 0) { _tmp++; }
        return (x_e45) * (a_5fc3(x_e45 - 1));
    }
}