Bleichenbacher Attack PoC – INFO-F514

This repository contains a proof of concept (PoC) for the Bleichenbacher attack, implemented as part of the INFO-F514 course project.

The Bleichenbacher attack targets RSA encryption implementations that are vulnerable to padding oracle attacks, allowing attackers to decrypt ciphertexts without access to the private key. This PoC demonstrates the feasibility of such an attack targetting the python library pyca/cryptography in version 3.1.1.

The project was originally intended to demonstrate a Marvin attack, a modern variation of Bleichenbacher's padding oracle attack that leverages side-channel information (such as timing differences). However, due to the time constraints and the complexity of implementing accurate side-channel measurements, the focus was shifted to a more classic Bleichenbacher approach using a simulated padding oracle.

Authors

• Bajraktari Eron (516414)
• Dhainaut Antoine (525982)
• Dupret Alexis (586999)
• Etienne Charles (616670)
• Pierret Valentin (610133)

Project Structure

poc-marvin/
├── src/                  # Source code of the attack
├── requirements.txt      # Python dependencies
├── README.md             
└── ...

Setup Instructions

To run this project locally, we recommend using a Python virtual environment to manage dependencies cleanly.

2. Create and Activate a Virtual Environment

python3 -m venv .venv
source .venv/bin/activate        # On Linux/macOS
# OR
.venv\Scripts\activate           # On Windows

3. Install Dependencies

Install all required Python libraries using the provided requirements.txt:

pip install -r requirements.txt

4. Run the PoC

Navigate to the src/ directory and run the main attack script:

python main.py