passive_scan - 基于http代理的web漏洞扫描器的实现


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软件简介

在WEB业务上线前,QA测试阶段,可将QA的浏览器代理设到一个指定的代理中或测试pc拨入特定的vpn中,QA在测试功能的同时,
安全测试也会在后台同步完成,其好处不言而喻。

该类扫描器常见的有2种:

  1. 代理式
  2. vpn + 透明代理

Note

本文只讲第1种,第2种的实现方式稍麻烦一些,一天半天的时间内写不出来,留在下篇文章中写。

架构说明

proxy模块的实现

用户请求数据抓取

proxy模块是在开源项目 https://github.com/senko/tornado-proxy
的基础上改的,将用户的请求与服务器的响应数据过滤后存入了mongodb中。 我新加的代码在30 - 38行之间。

class ProxyHandler(tornado.web.RequestHandler):
    SUPPORTED_METHODS = ['GET', 'POST', 'CONNECT']

    @tornado.web.asynchronous
    def get(self):
        url_info = dict(
            method=self.request.method,
            url=self.request.uri
        )
        self.request_info = None

        def handle_response(response):
            if (response.error and not
                    isinstance(response.error, tornado.httpclient.HTTPError)):
                self.set_status(500)
                self.write('Internal server error:\n' + str(response.error))
            else:
                self.set_status(response.code)
                for header in ('Date', 'Cache-Control', 'Server','Content-Type', 'Location'):
                    v = response.headers.get(header)
                    if v:
                        self.set_header(header, v)
                v = response.headers.get_list('Set-Cookie')
                if v:
                    for i in v:
                        self.add_header('Set-Cookie', i)
                if response.body:
                    self.write(response.body)

            # Insert http request  and response into mongodb
            if self.application.scan:
                url = url_info.get('url')
                url_filter = UrlFilter(url)
                if url_filter.filter():
                    http_info = HttpInfo(url_info, self.request_info, response)
                    values = http_info.get_info()
                    mongodb = Mongodb(db_info)
                    mongodb.insert(values)

            self.finish()

        body = self.request.body
        self.request_info = self.request
        if not body:
            body = None
        try:
            fetch_request(
                self.request.uri, handle_response,
                method=self.request.method, body=body,
                headers=self.request.headers, follow_redirects=False,
                allow_nonstandard_methods=True)

        except tornado.httpclient.HTTPError as e:
            if hasattr(e, 'response') and e.response:
                handle_response(e.response)
            else:
                self.set_status(500)
                self.write('Internal server error:\n' + str(e))
                self.finish()

程序使用方法

Note

代码比较占篇幅,这里不贴了,请参考我的github: https://github.com/netxfly/passive_scan

proxy有2个参数:

  1. port,端口不指定的话,默认为8088
  2. scan,scan默认为true,表示会将用户信息入库,如果单纯只想作为一个代理,传入false即可。

任务分发模块

Note

任务分发模块会定期检查mongodb中的待扫描列表,根据status字段判断是否有扫描任务,如果有扫描任务就分发给celery的worker执行。

  1. status = 0,表示待扫描
  2. status = 1,表示正在扫描
  3. status = 2,表示扫描已完成

    -- coding: utf-8 --

    author = ‘Hartnett’

    import time
    from pprint import pprint
    import pymongo
    from bson.objectid import ObjectId

    from config import db_info
    from scan_tasks import scan

    class Scheduler(object):
    def init(self, interval=5):
    self.interval = interval
    self.db_info = db_info

        # connect to database
        self.client = pymongo.MongoClient(self.db_info.get('host'), self.db_info.get('port'))
        self.client.security_detect.authenticate(
            self.db_info.get('username'),
            self.db_info.get('password'),
            source='passive_scan'
        )
    
        self.db = self.client["passive_scan"]
        self.collection = self.db['url_info']
    
    def _get_task(self):
        task_id = None
        task_info = None
        tasks = self.collection.find({'status' : 0}).sort("_id", pymongo.ASCENDING).limit(1)
        for task in tasks:
    
            url = task.get('url')
            task_id = task.get('_id')
            domain = task.get('domain')
            method = task.get('request').get('method')
            request_data = task.get('request').get('request_data')
            user_agent = task.get('request').get('headers').get('User-Agent')
            cookies = task.get('request').get('headers').get('Cookie')
            task_info = dict(
                task_id=task_id,
                url=url,
                domain=domain,
                method=method,
                request_data=request_data,
                user_agent=user_agent,
                cookies=cookies
            )
    
        print("task_id : %s, \ntask_info:") % task_id
        pprint(task_info)
        return task_id, task_info
    
    # set task checking now
    def _set_checking(self, task_id):
        self.collection.update({'_id': ObjectId(task_id)}, {"$set" : {'status' : 1}})
    
    # set task checked
    def _set_checked(self, task_id):
        self.collection.update({'_id': ObjectId(task_id)}, {"$set" : {'status' : 2}})
    
    # distribution task
    def distribution_task(self):
        task_id, task_info = self._get_task()
        print "get scan task done, sleep %s second." % self.interval
        if task_id is not None:
            self._set_checking(ObjectId(task_id))
            url = task_info.get('url')
            domain = task_info.get('domain')
            method=task_info.get('method')
            request_data=task_info.get('request_data')
            user_agent = task_info.get('user_agent')
            cookies = task_info.get('cookies')
            scan.apply_async((task_id,url,domain,method,request_data,user_agent,cookies,))
    
            self._set_checked(ObjectId(task_id))
    
    def run(self):
        while True:
            self.distribution_task()
            time.sleep(self.interval)
    

    if name == ‘main’:
    scheduler = Scheduler()
    scheduler.run()

扫描任务执行模块

Note

任务扫描模块是利用celery实现分布式扫描的,可以将worker部署在多台服务器中,后端的扫描器大家根据实现情况加,比如wvs,arachni,wvs或自己写的扫描器
,这篇文章的重点在于代理扫描,我图方便就用了 arachni 。

# -*- coding:utf8 -*-
__author__ = 'hartnett'
from celery import Celery
from arachni import arachni_console

from config import BACKEND_URL, BROKER_URL, db_info
from helper import Reporter, PassiveReport, TaskStatus

app = Celery('task', backend=BACKEND_URL, broker=BROKER_URL)

# scanning url task
# --------------------------------------------------------------------
@app.task
def scan(task_id, task_url,domain,method,request_data,user_agent,cookies):
    if task_url:
        print "start to scan %s, task_id: %s" % (task_url, task_id)
        scanner = arachni_console.Arachni_Console(task_url, user_agent, cookies,page_limit=1)
        report = scanner.get_report()
        if report:
            reporter = Reporter(report)
            value = reporter.get_value()
            if value:
                # 如果存在漏洞则记录到数据库中
                scan_report = PassiveReport(db_info, value)
                scan_report.report()

        task_status = TaskStatus(db_info)
        # 将状态设为已扫描
        task_status.set_checked(task_id)

web管理后台

实现这个demo用了半天时间,写web后台还要处理前端展示,比较麻烦,所以没写,只讲下基于proxy的扫描器的实现思路