Network Security with Python - Rishan Solutions

Network security focuses on protecting networks, systems, and data from cyber threats. Python provides powerful libraries for scanning, monitoring, intrusion detection, and penetration testing.

Key Areas of Network Security:

Port Scanning – Identifying open ports & vulnerabilities.
Packet Sniffing – Capturing & analyzing network traffic.
Firewall & IDS/IPS – Detecting and preventing attacks.
Intrusion Detection – Monitoring suspicious activity.
Secure Network Communication – Encrypting data transfers.

Installing Required Libraries

pip install scapy requests socket paramiko

1. Port Scanning with Python (Using socket)

Identify open ports on a target machine.

import socket

def scan_ports(target, ports):
    for port in ports:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(1)
        result = sock.connect_ex((target, port))
        if result == 0:
            print(f"Port {port} is OPEN")
        sock.close()

# Example usage
scan_ports("scanme.nmap.org", [21, 22, 80, 443])

Detect open ports & vulnerabilities.

2. Packet Sniffing with Scapy

Capture and analyze network packets.

from scapy.all import sniff

def packet_callback(packet):
    print(packet.summary())

# Sniff packets (requires admin privileges)
sniff(prn=packet_callback, count=5)

Monitor network traffic & detect threats.

3. Intrusion Detection (Detecting Suspicious Traffic)

from scapy.all import sniff, IP, TCP

def detect_intrusion(packet):
    if packet.haslayer(IP):
        if packet[IP].src == "192.168.1.100":  # Example: Detect traffic from a specific IP
            print(f"Possible intrusion detected from {packet[IP].src}")

sniff(prn=detect_intrusion, count=10)

Identify malicious traffic from attackers.

4. Secure SSH Connection (Using Paramiko)

import paramiko

def secure_ssh_login(host, username, password):
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    try:
        ssh.connect(host, username=username, password=password)
        print("SSH Connection Successful ✅")
    except:
        print("SSH Connection Failed ❌")

# Example usage
secure_ssh_login("192.168.1.1", "admin", "password123")

Protect against SSH brute-force attacks.

5. Preventing Brute Force Attacks (Blocking Failed Logins)

failed_attempts = {}

def check_login_attempt(ip):
    if ip not in failed_attempts:
        failed_attempts[ip] = 1
    else:
        failed_attempts[ip] += 1

    if failed_attempts[ip] > 3:  # Block IP after 3 failed attempts
        print(f"Blocking IP: {ip} due to multiple failed attempts!")

# Example usage
check_login_attempt("192.168.1.50")
check_login_attempt("192.168.1.50")
check_login_attempt("192.168.1.50")
check_login_attempt("192.168.1.50")  # This should trigger blocking

Enhance authentication security.

6. Secure Network Communication with SSL/TLS

import ssl
import socket

context = ssl.create_default_context()

def secure_server_connection(host, port):
    with socket.create_connection((host, port)) as sock:
        with context.wrap_socket(sock, server_hostname=host) as secure_sock:
            print(secure_sock.version())

# Example usage
secure_server_connection("www.google.com", 443)

Ensure encrypted communication over the network.

When to Use Network Security in Python?

✔ Penetration Testing – Identify security flaws in networks.
✔ Intrusion Detection – Monitor and detect cyber attacks.
✔ Secure Data Transmission – Encrypt communications.
✔ Automated Network Monitoring – Detect suspicious activity.