SketchObfus

• Focused on what it does best: making things slightly uglier.
• This program relies on Regex to "detect" variable/function names, rather than using a Abstract Syntax Tree.

before	after

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🔧 Features

• Removes both C-style (/* */) and C++-style (//) comments
• Obfuscates:
  • Global and local variables
  • Function names
  • Function parameters
  • Object instances (e.g., Servo myServo;)
• Ignores Arduino reserved keywords and function names
• Outputs clean, comment-free obfuscated code

📦 Requirements

• Python 3.13

🚀 Usage

1. via python interpreter

(1) Clone this project

git clone https://github.com/brianoy/SketchObfus.git

(2) Start obfuscated the code

python SketchObfus.py your_sketch.ino

This generates an obfuscated version of the sketch named your_sketch_obf.ino.

You can also specify a custom output filename:

python SketchObfus.py your_sketch.ino obfuscated_output.ino

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2. via cmd command

lastest binary download

(1) Clone this project

git clone https://github.com/brianoy/SketchObfus.git

(2) Compile the python script

pip install auto-py-to-exe

Compiling with "Nuitka" may cause Windows Defender to flag the generated .exe as a malicious file, use pyinstaller instead.

pyinstaller --noconfirm --onefile --console .\SketchObfus.py

(3) Start obfuscated the code

You will see the exe file under dist folder, open a cmd window and execute it by:

SketchObfus.exe your_sketch.ino

You can also specify a custom output filename:

SketchObfus.exe your_sketch.ino obfuscated_output.ino

📁 Example

Before:

int ledPin = 13;
void setup() {
  pinMode(ledPin, OUTPUT);
}
void loop() {
  digitalWrite(ledPin, HIGH);
  delay(1000);
  digitalWrite(ledPin, LOW);
  delay(1000);
}

After:

int _0xA3B1C2D4 = 13;
void setup() {
  pinMode(_0xA3B1C2D4, OUTPUT);
}
void loop() {
  digitalWrite(_0xA3B1C2D4, HIGH);
  delay(1000);
  digitalWrite(_0xA3B1C2D4, LOW);
  delay(1000);
}

🛡️ Limitations

• Not suitable for sketches that rely on external macro-generated names or dynamically referenced variables.
• Does not analyze code semantically — relies solely on regex patterns.

🤝 Contributing

• 🐛 Found a bug? Feel free to open an issue.