NetworkGroupProject

Cmpt361 Group Project

Overview

Our project has the following key features:

1. Secure Communication: The client and server communicate using RSA encryption for the initial handshake and AES encryption for the message exchange. This ensures the confidentiality of the communication
2. User Authentication: The servr verifies the client's username and password before allowing access to the email system.
3. Email Functinoality: The client can send emails, view their inbox, and read individual emails. The emails are stored on the server's file system.
4. Scalability: The server can handle multiple client connections simultaneously using a fork-based approach.
5. Replay Attack Protection: Enhanced program versions (Server_enhanced.py + Client_enhanced.py) include protections against replay attacks using nonces and timestamps.

Components

Our project consists of the following components:

1. Server:

• Handles client connections and authentication
• Supports five simultaneous client connections
• Generates and manages symmetric keys for encryption.
• Saves and retrieves emails from the file system.

2. Client:

• Establishes a connection with the server.
• Authenticates with the server using a username and password.
• Send emails, views the inbox, and reads individual emails.
• Handles file-based email content imports

3. Key Generator:

• Generates RSA key pairs for the server and clients.
• Saves the keys in the appropriate directories
• Generates user credentials file and directory structures if necessary

Security Features

1. Basic Security (Original):

• RSA encryption for authentication
• AES encryption for messages exchange
• Password-based authentication

2. Enhanced Security:

• Protection against replay attacks
• Nonce-based challenge-response implementation
• Timestamp verification
• Session tracking

Usage

1. Run the 'key_generator.py' script to generate the necessary keys.
2. Run either 'Server.py' or 'Server_enhanced.py' to start the email server.
3. Run either 'Client.py'or 'Client_enhanced.py' to connect to the server and use the email system.

Error handling cases

• Invalid credentials detection
• File not found for email imports
• Invalid email indexing
• Connection timeouts