20199325 2019-2020-2 实践三网络嗅探与协议分析实践

Posted 2021-03-03 buhery

20199325 2019-2020-2 实践三网络嗅探与协议分析实践

---

目录

• 实验三:
  • 任务一:根据教材参考代码，编写有个简单网络抓包工具,要求核心代码和运行结果截图1-2张。代码push到码云
  • 任务二找一个网站或者搭建一个本地网站，登录网站，并嗅探，分析出账号和密码，结果截图1-2张。（3分）
  • 任务三： 抓取手机App的登录过程数据包，分析账号和密码。可以用邮箱、各类博客、云班课。

实验三:

任务一:根据教材参考代码，编写有个简单网络抓包工具,要求核心代码和运行结果截图1-2张。代码push到码云

#coding:UTF-8
from scapy.all import *
import time

class PcapDecode:
    def __init__(self):     
    #ETHER:读取以太网层协议配置文件
    with open(‘./protocol/ETHER‘, ‘r‘, encoding=‘UTF-8‘) as f:
            ethers = f.readlines()
        self.ETHER_DICT = dict()
        for ether in ethers:
            ether = ether.strip().strip(‘
‘).strip(‘
‘).strip(‘
‘)
            self.ETHER_DICT[int(ether.split(‘:‘)[0])] = ether.split(‘:‘)[1]  # 将配置文件中的信息(0257:Experimental)存入dict
    # IP:读取IP层协议配置文件
    with open(‘./protocol/IP‘, ‘r‘, encoding=‘UTF-8‘) as f:
        ips = f.readlines()
    self.IP_DICT = dict()
    for ip in ips:
        ip = ip.strip().strip(‘
‘).strip(‘
‘).strip(‘
‘)
        self.IP_DICT[int(ip.split(‘:‘)[0])] = ip.split(‘:‘)[1]  # 将配置文件中的信息(41:IPv6)存入dic

    # PORT:读取应用层协议端口配置文件
    with open(‘./protocol/PORT‘, ‘r‘, encoding=‘UTF-8‘) as f:
        ports = f.readlines()
    self.PORT_DICT = dict()
    for port in ports:
        port = port.strip().strip(‘
‘).strip(‘
‘).strip(‘
‘)
        self.PORT_DICT[int(port.split(‘:‘)[0])] = port.split(‘:‘)[1]  # 如：21:FTP

    # TCP:读取TCP层协议配置文件
    with open(‘./protocol/TCP‘, ‘r‘, encoding=‘UTF-8‘) as f:
        tcps = f.readlines()
    self.TCP_DICT = dict()
    for tcp in tcps:
        tcp = tcp.strip().strip(‘
‘).strip(‘
‘).strip(‘
‘)
        self.TCP_DICT[int(tcp.split(‘:‘)[0])] = tcp.split(‘:‘)[1]  # 465:SMTPS

    # UDP:读取UDP层协议配置文件
    with open(‘./protocol/UDP‘, ‘r‘, encoding=‘UTF-8‘) as f:
        udps = f.readlines()
    self.UDP_DICT = dict()
    for udp in udps:
        udp = udp.strip().strip(‘
‘).strip(‘
‘).strip(‘
‘)
        self.UDP_DICT[int(udp.split(‘:‘)[0])] = udp.split(‘:‘)[1]  # 513:Who

# 解析以太网层协议 ---ether_decode——ip_decode(tcp_decode or udp_decode)
def ether_decode(self, p):
    data = dict()  # 解析出的信息以dict的形式保存
    if p.haslayer("Ether"):  # scapy.haslayer,将pcap包中的信息分层，再处理
        data = self.ip_decode(p)  # 解析IP层协议
        return data
    else:
        data[‘time‘] = time.strftime(‘%Y-%m-%d %H:%M:%S‘, time.localtime(p.time))
        data[‘Source‘] = ‘Unknow‘
        data[‘Destination‘] = ‘Unknow‘
        data[‘Procotol‘] = ‘Unknow‘
        data[‘len‘] = len(corrupt_bytes(p))
        data[‘info‘] = p.summary()
        return data

#解析IP层协议
def ip_decode(self, p):
    data = dict()
    if p.haslayer("IP"):  #2048:Internet IP (IPv4) ，分IPV4和IPV6和其他协议
        ip = p.getlayer("IP")
        if p.haslayer("TCP"):  #6:TCP
            data = self.tcp_decode(p, ip)
            return data
        elif p.haslayer("UDP"): #17:UDP
            data = self.udp_decode(p, ip)
            return data
        else:
            if ip.proto in self.IP_DICT:  # 若ip分层中的协议信息在字典中，则提取ip分层中的源地址、目的地址、协议（转换）等
                data[‘time‘] = time.strftime(‘%Y-%m-%d %H:%M:%S‘, time.localtime(p.time))
                data[‘Source‘] = ip.src
                data[‘Destination‘] = ip.dst
                data[‘Procotol‘] = self.IP_DICT[ip.proto]
                data[‘len‘] = len(corrupt_bytes(p))
                data[‘info‘] = p.summary()
                return data
            else:
                data[‘time‘] = time.strftime(‘%Y-%m-%d %H:%M:%S‘, time.localtime(p.time))
                data[‘Source‘] = ip.src
                data[‘Destination‘] = ip.dst
                data[‘Procotol‘] = ‘IPv4‘
                data[‘len‘] = len(corrupt_bytes(p))
                data[‘info‘] = p.summary()
                return data
    elif p.haslayer("IPv6"):  #34525:IPv6
        ipv6 = p.getlayer("IPv6")
        if p.haslayer("TCP"):  #6:TCP
            data = self.tcp_decode(p, ipv6)
            return data
        elif p.haslayer("UDP"): #17:UDP
            data = self.udp_decode(p, ipv6)
            return data
        else:
            if ipv6.nh in self.IP_DICT:
                data[‘time‘] = time.strftime(‘%Y-%m-%d %H:%M:%S‘, time.localtime(p.time))
                data[‘Source‘] = ipv6.src
                data[‘Destination‘] = ipv6.dst
                data[‘Procotol‘] = self.IP_DICT[ipv6.nh]
                data[‘len‘] = len(corrupt_bytes(p))
                data[‘info‘] = p.summary()
                return data
            else:
                data[‘time‘] = time.strftime(‘%Y-%m-%d %H:%M:%S‘, time.localtime(p.time))
                data[‘Source‘] = ipv6.src
                data[‘Destination‘] = ipv6.dst
                data[‘Procotol‘] = ‘IPv6‘
                data[‘len‘] = len(corrupt_bytes(p))
                data[‘info‘] = p.summary()
                return data
    else:
        if p.type in self.ETHER_DICT:
            data[‘time‘] = time.strftime(‘%Y-%m-%d %H:%M:%S‘, time.localtime(p.time))
            data[‘Source‘] = p.src
            data[‘Destination‘] = p.dst
            data[‘Procotol‘] = self.ETHER_DICT[p.type]
            data[‘len‘] = len(corrupt_bytes(p))
            data[‘info‘] = p.summary()
            return data
        else:
            data[‘time‘] = time.strftime(‘%Y-%m-%d %H:%M:%S‘, time.localtime(p.time))
            data[‘Source‘] = p.src
            data[‘Destination‘] = p.dst
            data[‘Procotol‘] = hex(p.type)  # 若在字典中没有改协议，则以16进制的形式显示
            data[‘len‘] = len(corrupt_bytes(p))
            data[‘info‘] = p.summary()
            return data

#解析TCP层协议
def tcp_decode(self, p, ip):
    data = dict()
    tcp = p.getlayer("TCP")
    data[‘time‘] = time.strftime(‘%Y-%m-%d %H:%M:%S‘, time.localtime(p.time))
    data[‘Source‘] = ip.src + ":" + str(ip.sport)
    data[‘Destination‘] = ip.dst + ":" + str(ip.dport)
    data[‘len‘] = len(corrupt_bytes(p))
    data[‘info‘] = p.summary()
    if tcp.dport in self.PORT_DICT:  #若端口信息在PORT_DICTTCP_DICT中则转换为已知
        data[‘Procotol‘] = self.PORT_DICT[tcp.dport]
    elif tcp.sport in self.PORT_DICT:
        data[‘Procotol‘] = self.PORT_DICT[tcp.sport]
    elif tcp.dport in self.TCP_DICT:
        data[‘Procotol‘] = self.TCP_DICT[tcp.dport]
    elif tcp.sport in self.TCP_DICT:
        data[‘Procotol‘] = self.TCP_DICT[tcp.sport]
    else:
        data[‘Procotol‘] = "TCP"
    return data

#解析UDP层协议
def udp_decode(self, p, ip):
    data = dict()
    udp = p.getlayer("UDP")
    data[‘time‘] = time.strftime(‘%Y-%m-%d %H:%M:%S‘, time.localtime(p.time))
    data[‘Source‘] = ip.src + ":" + str(ip.sport)
    data[‘Destination‘] = ip.dst + ":" + str(ip.dport)
    data[‘len‘] = len(corrupt_bytes(p))
    data[‘info‘] = p.summary()
    
    #这里定义的是解析UDP协议中的五元组，分别是time，source，destination，len，info。这也是仿照wireshark进行分析的。

    if udp.dport in self.PORT_DICT:  #若端口信息在PORT_DICTUDP_DICT中则转换为已知
        data[‘Procotol‘] = self.PORT_DICT[udp.dport]
    elif udp.sport in self.PORT_DICT:
        data[‘Procotol‘] = self.PORT_DICT[udp.sport]
    elif udp.dport in self.UDP_DICT:
        data[‘Procotol‘] = self.UDP_DICT[udp.dport]
    elif udp.sport in self.UDP_DICT:
        data[‘Procotol‘] = self.UDP_DICT[udp.sport]
    else:
        data[‘Procotol‘] = "UDP"
    return data
if __name__ == ‘__main__‘:
# pkts = sniff(iface="eth0",count=3) 简单的抓取数据包
# wrpcap("demo.pcap", pkts)  保存为demo.pcap
    
PD = PcapDecode()  # 实例化该类为PD
pcap_test = rdpcap("demo.pcap")  # 这个demo.pcap包含3次连接
data_result = dict()  # 将解析结果存入dict
for p in pcap_test:
    data_result = PcapDecode.ether_decode(PD, p)
    print(data_result)

我使用的Python的Scapy进行的抓包和pcap分析。这是一个很经常使用的python库。解析出来的pcap包以五元组的形式出来。

任务二找一个网站或者搭建一个本地网站，登录网站，并嗅探，分析出账号和密码，结果截图1-2张。（3分）

查看到天翼快递，目前应用的都是https协议，只有http协议的网站大部分都是明文传输。所以这个网站可以通过抓包直接找到POST方法的提交的用户和密码

任务三： 抓取手机App的登录过程数据包，分析账号和密码。可以用邮箱、各类博客、云班课。

两个网站都进行尝试，手机端好像因为浏览器的问题，没能查到POST提交的用户名和密码。时间较短，没有进行详细的查看。