Python网页分析httplib库的重定向处理

Posted 2020-07-26 inns

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

 

 

2. Python模拟

2.1 抓包分析，后面的GET方法发送不去

 

 

再查看IE上抓包结果

没有出现GET方法

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。

 

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，

 

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。

 

 

去掉这个头

查看Python的消息流程正常

 

 

 

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