正文

揭秘端口扫描技巧：五大分类详解，轻松应对网络安全挑战

/0 浏览量
0622

网络安全对于任何组织和个人来说都是一个至关重要的话题。在众多安全措施中，端口扫描是保障网络安全的第一步。本文将详细介绍五大端口扫描分类及其技巧，帮助大家更好地应对网络安全挑战。

一、基于TCP的端口扫描

TCP（传输控制协议）端口扫描是最常见的端口扫描方式。以下列举几种基于TCP的端口扫描技巧：

1. SYN扫描

SYN扫描（也称为半开放扫描）通过发送一个SYN包并监听ACK包来确定端口是否开放。如果目标端口开放，则会收到一个SYN/ACK包；如果端口关闭，则会收到一个RST包。

import socket

def syn_scan(host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.settimeout(1)
    try:
        sock.connect((host, port))
        print(f"Port {port} is open.")
    except socket.error as e:
        print(f"Port {port} is closed.")
    finally:
        sock.close()

syn_scan('example.com', 80)

2. FIN扫描

FIN扫描通过发送一个FIN包来检查目标端口是否开放。如果目标端口开放，则会收到一个RST包；如果端口关闭，则会收到一个ACK包。

import socket

def fin_scan(host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.settimeout(1)
    try:
        sock.sendto(b'\x15', (host, port))
        response = sock.recvfrom(1024)
        if response[0][0] == 0x06:  # RST packet
            print(f"Port {port} is closed.")
        else:
            print(f"Port {port} is open.")
    except socket.error as e:
        print(f"Port {port} is open.")
    finally:
        sock.close()

fin_scan('example.com', 80)

二、基于UDP的端口扫描

UDP（用户数据报协议）端口扫描与TCP端口扫描有所不同。以下是两种基于UDP的端口扫描技巧：

1. UDP端口扫描

UDP端口扫描通过发送UDP数据包到目标端口，并根据目标端口是否响应来判断端口是否开放。

import socket

def udp_scan(host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.settimeout(1)
    try:
        sock.sendto(b'\x00\x01\x02\x03', (host, port))
        response = sock.recvfrom(1024)
        if response[0][0] != 0:
            print(f"Port {port} is open.")
        else:
            print(f"Port {port} is closed.")
    except socket.error as e:
        print(f"Port {port} is open.")
    finally:
        sock.close()

udp_scan('example.com', 80)

2. NULL扫描

NULL扫描通过发送一个不包含任何有效IP头部和TCP头部的数据包来检查目标端口是否开放。

import socket

def null_scan(host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.settimeout(1)
    try:
        sock.sendto(b'\x00\x00\x00\x00', (host, port))
        response = sock.recvfrom(1024)
        if response[0][0] != 0:
            print(f"Port {port} is open.")
        else:
            print(f"Port {port} is closed.")
    except socket.error as e:
        print(f"Port {port} is open.")
    finally:
        sock.close()

null_scan('example.com', 80)

三、基于ICMP的端口扫描

ICMP（互联网控制消息协议）端口扫描通过发送一个ICMP数据包来检查目标端口是否开放。以下是一个基于ICMP的端口扫描示例：

import socket
import struct

def icmp_scan(host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.settimeout(1)
    try:
        packet = struct.pack('!BBHHH', 8, 0, 0, 0, 8192)
        sock.sendto(packet, (host, port))
        response = sock.recvfrom(1024)
        if response[0][0] == 3:  # Destination Unreachable
            print(f"Port {port} is closed.")
        else:
            print(f"Port {port} is open.")
    except socket.error as e:
        print(f"Port {port} is open.")
    finally:
        sock.close()

icmp_scan('example.com', 80)

四、基于SYN/ACK/Fin的端口扫描

SYN/ACK/Fin端口扫描是一种结合了SYN扫描、ACK扫描和Fin扫描的端口扫描方法。以下是一个基于SYN/ACK/Fin的端口扫描示例：

import socket

def syn_ack_fin_scan(host, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.settimeout(1)
    try:
        sock.sendall(b'\x15')
        response = sock.recvfrom(1024)
        if response[0][0] == 0x06:  # RST packet
            print(f"Port {port} is closed.")
        elif response[0][0] == 0x12:  # SYN/ACK packet
            print(f"Port {port} is open.")
        elif response[0][0] == 0x14:  # Fin packet
            print(f"Port {port} is open.")
        else:
            print(f"Port {port} is closed.")
    except socket.error as e:
        print(f"Port {port} is open.")
    finally:
        sock.close()

syn_ack_fin_scan('example.com', 80)

五、总结

端口扫描是网络安全的重要组成部分。掌握不同的端口扫描技巧可以帮助我们更好地了解目标主机，从而采取相应的安全措施。本文详细介绍了五大端口扫描分类及其技巧，希望对您有所帮助。

-- 展开阅读全文 --