LocalStream Application

Overview

LocalStream is a Python-based application designed for secure and efficient file transfer over a local network. It incorporates advanced encryption mechanisms for secure data transmission and supports robust session management to ensure reliable connections.

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Usage

This project provides a command-line interface (CLI) to manage both server and client-side file operations. The commands are handled via the fire library, which provides a simple and flexible way to interact with the application from the command line.

Start the CLI:

   python localstream.py

The CLI class defines the command-line interface commands that can be executed by the user.

Server-Side Commands

1. Add a Connection

   • Command: add_connection
   • Arguments:
     • port (int) - The port number the server will listen to.
     • max_connections (int, optional, default: 1) - Maximum number of connections allowed.
   • Example:

     add_connection 8080 10

   • Description: Adds a new connection on the server to allow clients to connect.

2. Add a Local Connection

   • Command: add_local_connection
   • Arguments:
     • host (str) - The IP address of the host.
     • port (int) - The port number.
     • max_connections (int) - Maximum number of connections allowed.
   • Example:

     add_local_connection 192.168.1.1 8080 10

   • Description: Adds a local connection to the server with the provided host and port.

3. Delete a Connection

   • Command: del_connection
   • Arguments:
     • port (int) - The port number of the connection to delete.
   • Example:

     del_connection 8080

   • Description: Removes an existing connection from the server based on the provided port.

4. Send a File

   • Command: send_file
   • Arguments:
     • port (int) - The port of the connection.
     • file_path (str) - The path of the file to send.
     • chunk_size (int, optional, default: 1024) - Size of chunks for file transfer.
   • Example:

     send_file 8080 /path/to/file.txt 2048

   • Description: Sends a file to the connected client.

5. List Possible Connections

   • Command: possible_connections
   • Arguments: None
   • Example:

     possible_connections

   • Description: Lists all the available possible connections on the server.

6. Get Server Status

   • Command: status
   • Arguments: None
   • Example:

     status

   • Description: Displays the current status of the server, including active connections.

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Client-Side Commands

1. Connect to Server

   • Command: connect
   • Arguments:
     • host (str) - The IP address of the server.
     • port (int) - The port number of the server.
   • Example:

     connect 192.168.1.1 8080

   • Description: Connects the client to the server at the specified host and port.

2. Receive a File

   • Command: receive_file
   • Arguments:
     • file_save_path (str) - The path where the file will be saved on the client-side.
   • Example:

     receive_file /path/to/save/file.txt

   • Description: Receives a file from the server and saves it to the specified path.

3. Exit CLI

   • Command: exit
   • Arguments: None
   • Example:

     exit

   • Description: Exits the CLI application.

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Additional Notes:

• Ensure that both server and client devices are on the same network.
• All files transferred are encrypted for security.

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Libraries

Language:

• Python Version: Python 3.8 or higher is required.

Standard Libraries:

• socket: Facilitates communication over the network.
• os: Manages file and directory operations.
• json: Handles configuration and session data.
• base64: Used for encoding and decoding data.
• uuid: Generates unique identifiers for identifying devices and sessions.

Third-Party Libraries

• cryptography: For encryption and key management.
• fire: For building the command-line interface (CLI).
• netifaces: For interacting with network interfaces and retrieving MAC/IP addresses.

To install dependencies, run:

pip install -r requirements.txt

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Modules

Connections

client.py

Handles client-side network interactions. Main responsibilities include:

• Establishing a connection to the server.
• Sending files securely after encryption.
• Managing error handling during transmission.

server.py

Listens for client connections and processes incoming encrypted files. Features:

• Handles decryption and stores the received files.
• Verifies client credentials using session keys.

connection_management.py

Utility functions supporting connections:

• Socket setup and configuration.
• Error handling for failed connection attempts.

new_connection.py

Responsible for initializing and validating new client connections:

• Exchanges public keys for secure session setup.
• Ensures clients are authenticated before accepting files.

server_message_flags.json

A configuration file containing predefined flags for server responses, such as success, error, and status codes.

Files

file_manager.py

Core module for file operations:

• Encrypts files on the client-side before transmission.
• Decrypts files on the server-side after receipt.
• Validates file integrity post-transfer.

error_handler.py

Custom error-handling utilities for:

• Logging connection or file transfer errors.
• Gracefully recovering from failures without terminating the application.

Session

session_manager.py

Manages session-level operations:

• Stores session data (e.g., client MAC addresses and encryption keys) in JSON format.
• Ensures persistent logging of active sessions.
• Supports secure retrieval of session-related information.

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Features

1. End-to-End Encryption:

   • Files are encrypted using AES before transmission.
   • Public-key exchange using RSA ensures secure key sharing.

2. Session Management:

   • Tracks client sessions, ensuring secure, authenticated connections.

3. Modular Architecture:

   • Each component is self-contained, making the application scalable and easy to maintain.

4. Cross-Platform Compatibility:

   • Works on any system supporting Python 3.8+.

5. Customizable:

   • Easily adaptable to include additional encryption methods or file transfer protocols.

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License

LocalStream is licensed under the MIT License. See LICENSE.md for details.

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