Secure-File-Storage-as-a-Service

SFSaaS is a cloud simulation project that mimics the behavior of a secure file storage system. This project demonstrates key concepts of cloud storage, cryptography, authentication mechanisms, and client-server communication using gRPC.

🔐 Key Features

• Asymmetric Cryptography: A custom cryptographic algorithm is implemented to generate asymmetric key pairs used to secure communication between the client and the server.
• gRPC Communication: The server uses Google Remote Procedure Call (gRPC) to simulate fast and efficient communication between clients and the cloud server.
• Two-Factor Authentication:
  • Machine Authentication: The client machine is authenticated using a simulated digital certificate (represented as a Python dictionary).
  • User Authentication: After the machine is verified, the user must authenticate using a username and password.
• User can only access their files: A user can't access another user file.
• File Storage Simulation: Mimics a secure and structured file storage system in the cloud.

📁 Project Structure

The system is built on a client-server architecture:

• grpc Cloud Server: Handles file storage operations, authentication requests, and manages user sessions
• Client: Provides interface for users to interact with the cloud storage system
• Authentication Module: Processes two-factor authentication (machine + user)
• Cryptography Module: Manages key generation, encryption, and decryption

🚀 Getting Started

Prerequisites

• Python 3.8+
• grpcio and grpcio-tools
• cryptography

Installation

1. Clone the repository
2. pip install -r requirements.txt
3. To run the cloud server : python3 cloud_server_grpc.py
4. To run a client : python3 cloud_client.py

📚 Technologies Used

Python
gRPC
Custom Cryptographic Algorithms

Technical Details

Cryptography Implementation

• The system implements a custom asymmetric key generation algorithm that: Creates public-private key pairs for secure communication Ensures data confidentiality and integrity during transmission Provides non-repudiation for critical operations

Authentication Flow

• Machine Authentication: Client machine presents its digital certificate Server validates certificate authenticity If valid, proceeds to user authentication

• User Authentication: User provides username and password Server verifies credentials against stored data Upon successful verification, grants access to cloud resources

• User The Following credential to authenticate:

• Username : Neymar

• Password : BestPlayer

• You can have other credential by doing static code analysis

CTF

• Produse a man in the middle attack and try to intercep data that are not encrypted
• Encrypt the rest of data that have not been encrypted