【Python网页分析】httplib库的重定向处理

1. 网页处理

下图是实际操作抓包分析结果,其他的步骤不再描述。

1、从选定的POST /main.aspx开始

2、后面服务器回复302重定向到/cd_chose.aspx页面

3、抓包数据有GET重定向URL,GET css和js文件不再赘述

4、POST到/cd_chose.aspx

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2. Python模拟

2.1 抓包分析,后面的GET方法发送不去

image

再查看IE上抓包结果

image

没有出现GET方法

image

怀疑是需要直接POST,尝试了之后仍然失败,但仔细看了下POST内容,头里面有GET头,由于不太了解IE的头显示,不再深究。

image

2.2 检查消息格式

由于GET这个重定向页面之前定义了HTTP头,

image

对比网页上实际操作成功发送的头,发现我在Python中多定义了一个头”Content-Type",主要是前面的POST方法需要和头

实际流程里面,前面其他GET消息需要这个头,但本消息中确实不需要这个头。

image

去掉这个头

查看Python的消息流程正常

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这个问题由于自己http基础不踏实,遇到问题不太确定方向,总觉得重定向流程有什么其他的复杂处理。耽搁了很多时间,

结果其实就只是一个头的问题。

最后附上封装的http get和post方法,调用的httplib库,比较灵活方便,可以根据前端js代码,模仿自己生成一些特殊字段认证服务器。

def http_get(self,connDefault=None,url='',bodyFlag=False,refererFresh=False,referer = ''):

        status,infor = 1,''       
        if connDefault is None:
            conn = HTTPConnection(self.host,timeout=60)
        else:
            conn = connDefault

        try:

            print 'http_get -> enter to get ',url
            start = time.time()           
           
            print 'http_get -> connect init OK'
            conn.request('GET',url,headers=self.headers)

            print 'http_get -> wait the  response...'
            response = conn.getresponse()
            end = time.time()
            print "http_get -> info:",end - start,response.status

            print 'http_get -> response headers' ,response.getheaders()

            #状态码
            status = response.status
            if status != 200:
                print 'http_get -> http status error',status
                infor = 'error'

            else:
                #获取Cookie,格式如下ASP.NET_SessionId=pzt0bs55tc2fjrbv0canht45; path=/; HttpOnly
                cookie=response.getheader('Set-Cookie','')
                #print "http_get -> cookie -> ",cookie

                """
                Cookie叠加
                """
                if cookie != '':
                    #cookie键值分两种类型
                    print 'http_get -> peer Set-Cookie'  , cookie
                    pattern = re.compile(r'(key=[w=+/]+;|ASP.NET_SessionId=[w=+/]+;)')
                    _list = pattern.search(cookie)
                    #print 'http_get -> _list',_list   
                    if _list is not None:
                        #print 'http_get -> _list' ,url,_list.groups()
                        oCookie = self.headers.get('Cookie','')
                        if oCookie == '':
                            self.headers["Cookie"] = str(_list.groups()[0][:-1])
                        else:
                            self.headers["Cookie"] = oCookie + ';'  + str(_list.groups()[0][:-1])
                        print 'http_get -> request Cookie' ,self.headers["Cookie"]
                    else:
                        pass
                else:
                    pass

                """
                更新Referer
                """

                if refererFresh:
                    if referer != '':
                        self.headers["Referer"] = "http://" + self.host + referer
                    else:
                        self.headers["Referer"] = "http://" + self.host + url


                #获取编码格式,gzip编码会在头中显示定义
                content_encoding = response.getheader('Content-Encoding','')
                if bodyFlag:
                    """
                    gzip解码
                    """
                    if content_encoding == 'gzip':
                        buf = StringIO(response.read())
                        infor = GzipFile(fileobj=buf).read()
                    else:
                        infor = response.read()

        except Exception,ex:
            print 'http_get -> error:',ex
            status,infor = 1,ex
        finally:
            if connDefault is None:
                conn.close()
            return status,infor


    def http_post(self,connDefault=None,url='',PostStr=''):
        status,response = 1,''
        try:
            headers = deepcopy(self.headers)
            headers["Content-Type"] ="application/x-www-form-urlencoded"
            start = time.time()
            if connDefault is None:
                conn = HTTPConnection(self.host,timeout=60)
            else:
                conn = connDefault

            headers["Content-Length"] = len(PostStr)
            conn.request('POST',url,PostStr,headers=headers)
            response = conn.getresponse()
            end = time.time()
            print "http_post info:",end - start,response.status
           
            #重定向
            if response.status == 302:
                Location=response.getheader('Location','')
                status,response = 302,Location
            #正常提交
            elif response.status == 200:
                status,response = 200,''
            else:
                status,response = response.status,'does not support'
        except Exception,ex:
            print 'http_post -> error:',ex
            status,response = 1,ex
        finally:
            if connDefault is None:
                conn.close()
            return status,response

好记性不如烂笔头
原文地址:https://www.cnblogs.com/inns/p/5596689.html