Secure Cloud-Based File Storage System

A client-server system that enables secure file storage on Google Drive using AES encryption, SSL/TLS for secure transmission, and TCP checksum verification for data integrity.

Project Overview

This project implements a secure cloud-based file storage system where clients can securely store and retrieve encrypted files from Google Drive. The system ensures end-to-end encryption with client-side key management.

Key Features

• End-to-End Encryption: Files are encrypted using AES before transmission
• Secure Communication: SSL/TLS encryption for client-server communication
• Data Integrity: TCP checksum verification ensures file integrity
• User-Friendly Interface: GUI for easy file management
• Cloud Storage: Integration with Google Drive for file storage
• Client-Side Key Management: Users maintain control of encryption keys

System Requirements

• Python 3.x
• Required packages:

  pycryptodome
  google-auth google-auth-oauthlib google-auth-httplib2 google-api-python-client
  PyQt5
  cryptography
  

Installation

1. Clone the repository:

   git clone https://github.com/yourusername/secure_transfer.git
   cd secure_transfer
   

2. Install required packages:

   pip install pycryptodome
   pip install google-auth google-auth-oauthlib google-auth-httplib2 google-api-python-client
   pip install PyQt5
   pip install cryptography
   

3. Generate SSL certificates (if not already included):

   openssl req -x509 -newkey rsa:4096 -keyout Server.key -out Server.crt -days 365 -nodes
   

4. Refer to CN Project Documentation.pdf for detailed explanation

5. Ensure that you have RSA Key, Certificate and have a valid Credentials.json file

Usage

Starting the Server

1. Navigate to the server directory:

   cd Server
   

2. Run the server:

   python run_server.py
   

3. The server will start and display its IP address and port number

Running the Client

1. Navigate to the client directory:

   cd Client
   

2. Ensure you have the Server.crt file in the Client directory

3. Start the client application:

   python run_client.py
   

4. Connect to the server by entering:

   • Server IP address
   • Server port number
   • Click "Connect"

File Operations

1. Uploading Files:

   • Click "Upload" button
   • Select file to upload
   • Choose or generate an AES key
   • The file will be encrypted and uploaded to Google Drive

2. Downloading Files:

   • Select the file from the list
   • Provide the correct AES key
   • Click "Download"
   • The file will be decrypted and saved locally

3. Key Management:

   • Generate new AES keys using the "Generate Key" option
   • Store keys securely - they are required for decryption
   • Lost keys cannot be recovered

Project Structure

Project Root/
├── Server/
│   ├── server.py
│   ├── run_server.py
│   ├── Server.crt
│   ├── Server.key
│   ├── encryption.py
│   ├── gdrive.py
│   ├── test_encryption.py
│   ├── Downloads/
│   └── Uploads/
└── Client/
    ├── gui.py
    ├── client.py
    ├── Server.crt
    └── run_client.py

Security Considerations

• Key Storage: The client must store all AES keys locally. Loss of a key means the encrypted file cannot be decrypted.
• Certificate Validation: The client must have a valid server certificate to connect.
• Server Security: The server does not store any files; it only handles encryption/decryption operations.

Troubleshooting

• Connection Issues: Verify server IP and port, check if server is running, ensure SSL certificate is valid
• Authentication Errors: Verify Google Drive credentials, check SSL certificate validity
• File Transfer Issues: Check network connectivity, verify file permissions, ensure sufficient storage space

Developers

• Adyansh Aggarwal (PES1UG23AM028)
• Akash Madisetty (PES1UG23AM035)

License

This project is licensed under the MIT License - see the LICENSE file for details.