深入了解mitmproxy（二）

主题
   修改request或者response内容

介绍
  mitmdump无交互界面的命令，与python脚本对接，来源于mitmproxy支持inline script，这里的script指的是python脚本，inline script提供了http、Websocket、tcp等各个时间点事件（events）的hook函数，如http中的request、response等

主要events一览表
   需要修改各种事件内容时，重写以下对应方法，这里主要用的是request、response方法

import typing

import mitmproxy.addonmanager
import mitmproxy.connections
import mitmproxy.http
import mitmproxy.log
import mitmproxy.tcp
import mitmproxy.websocket
import mitmproxy.proxy.protocol

class Events:
# HTTP lifecycle
def http_connect(self, flow: mitmproxy.http.HTTPFlow):
"""
An HTTP CONNECT request was received. Setting a non 2xx response on
the flow will return the response to the client abort the
connection. CONNECT requests and responses do not generate the usual
HTTP handler events. CONNECT requests are only valid in regular and
upstream proxy modes.
"""

def requestheaders(self, flow: mitmproxy.http.HTTPFlow):
    """
        HTTP request headers were successfully read. At this point, the body
        is empty.
    """

def request(self, flow: mitmproxy.http.HTTPFlow):
    """
        The full HTTP request has been read.
    """

def responseheaders(self, flow: mitmproxy.http.HTTPFlow):
    """
        HTTP response headers were successfully read. At this point, the body
        is empty.
    """

def response(self, flow: mitmproxy.http.HTTPFlow):
    """
        The full HTTP response has been read.
    """

def error(self, flow: mitmproxy.http.HTTPFlow):
    """
        An HTTP error has occurred, e.g. invalid server responses, or
        interrupted connections. This is distinct from a valid server HTTP
        error response, which is simply a response with an HTTP error code.
    """

# TCP lifecycle
def tcp_start(self, flow: mitmproxy.tcp.TCPFlow):
    """
        A TCP connection has started.
    """

def tcp_message(self, flow: mitmproxy.tcp.TCPFlow):
    """
        A TCP connection has received a message. The most recent message
        will be flow.messages[-1]. The message is user-modifiable.
    """

def tcp_error(self, flow: mitmproxy.tcp.TCPFlow):
    """
        A TCP error has occurred.
    """

def tcp_end(self, flow: mitmproxy.tcp.TCPFlow):
    """
        A TCP connection has ended.
    """

# Websocket lifecycle
def websocket_handshake(self, flow: mitmproxy.http.HTTPFlow):
    """
        Called when a client wants to establish a WebSocket connection. The
        WebSocket-specific headers can be manipulated to alter the
        handshake. The flow object is guaranteed to have a non-None request
        attribute.
    """

def websocket_start(self, flow: mitmproxy.websocket.WebSocketFlow):
    """
        A websocket connection has commenced.
    """

def websocket_message(self, flow: mitmproxy.websocket.WebSocketFlow):
    """
        Called when a WebSocket message is received from the client or
        server. The most recent message will be flow.messages[-1]. The
        message is user-modifiable. Currently there are two types of
        messages, corresponding to the BINARY and TEXT frame types.
    """

def websocket_error(self, flow: mitmproxy.websocket.WebSocketFlow):
    """
        A websocket connection has had an error.
    """

def websocket_end(self, flow: mitmproxy.websocket.WebSocketFlow):
    """
        A websocket connection has ended.
    """

# Network lifecycle
def clientconnect(self, layer: mitmproxy.proxy.protocol.Layer):
    """
        A client has connected to mitmproxy. Note that a connection can
        correspond to multiple HTTP requests.
    """

def clientdisconnect(self, layer: mitmproxy.proxy.protocol.Layer):
    """
        A client has disconnected from mitmproxy.
    """

def serverconnect(self, conn: mitmproxy.connections.ServerConnection):
    """
        Mitmproxy has connected to a server. Note that a connection can
        correspond to multiple requests.
    """

def serverdisconnect(self, conn: mitmproxy.connections.ServerConnection):
    """
        Mitmproxy has disconnected from a server.
    """

def next_layer(self, layer: mitmproxy.proxy.protocol.Layer):
    """
        Network layers are being switched. You may change which layer will
        be used by returning a new layer object from this event.
    """

# General lifecycle
def configure(self, updated: typing.Set[str]):
    """
        Called when configuration changes. The updated argument is a
        set-like object containing the keys of all changed options. This
        event is called during startup with all options in the updated set.
    """

def done(self):
    """
        Called when the addon shuts down, either by being removed from
        the mitmproxy instance, or when mitmproxy itself shuts down. On
        shutdown, this event is called after the event loop is
        terminated, guaranteeing that it will be the final event an addon
        sees. Note that log handlers are shut down at this point, so
        calls to log functions will produce no output.
    """

def load(self, entry: mitmproxy.addonmanager.Loader):
    """
        Called when an addon is first loaded. This event receives a Loader
        object, which contains methods for adding options and commands. This
        method is where the addon configures itself.
    """

def log(self, entry: mitmproxy.log.LogEntry):
    """
        Called whenever a new log entry is created through the mitmproxy
        context. Be careful not to log from this event, which will cause an
        infinite loop!
    """

def running(self):
    """
        Called when the proxy is completely up and running. At this point,
        you can expect the proxy to be bound to a port, and all addons to be
        loaded.
    """

def update(self, flows: typing.Sequence[mitmproxy.flow.Flow]):
    """
        Update is called when one or more flow objects have been modified,
        usually from a different addon.
    """

针对http，常用的API

http.HTTPFlow 实例 flow

flow.request.headers #获取所有头信息，包含Host、User-Agent、Content-type等字段
flow.request.url #完整的请求地址，包含域名及请求参数，但是不包含放在body里面的请求参数
flow.request.pretty_url #同flow.request.url目前没看出什么差别
flow.request.host #域名
flow.request.method #请求方式。POST、GET等
flow.request.scheme #什么请求 ，如https
flow.request.path # 请求的路径，url除域名之外的内容
flow.request.get_text() #请求中body内容，有一些http会把请求参数放在body里面，那么可通过此方法获取，返回字典类型
flow.request.query #返回MultiDictView类型的数据，url直接带的键值参数
flow.request.get_content()#bytes,结果如flow.request.get_text()
flow.request.raw_content #bytes,结果如flow.request.get_content()
flow.request.urlencoded_form #MultiDictView，content-type：application/x-www-form-urlencoded时的请求参数，不包含url直接带的键值参数
flow.request.multipart_form #MultiDictView，content-type：multipart/form-data
时的请求参数，不包含url直接带的键值参数

以上均为获取request信息的一些常用方法，对于response，同理

flow.response.status_code #状态码
flow.response.text#返回内容，已解码
flow.response.content #返回内容，二进制
flow.response.setText()#修改返回内容，不需要转码

以上为不完全列举

示例

修改response内容，这里是服务器已经有返回了结果，再更改，也可以做不经过服务器处理，直接返回，看需求

def response(flow:http.HTTPFlow)-> None:
#特定接口需要返回1001结果
interface_list=["page/**"] #由于涉及公司隐私问题，隐藏实际的接口

url_path=flow.request.path
if  url_path.split("?")[0] in  interface_list:
    ctx.log.info("#"*50)
    ctx.log.info("待修改路径的内容："+url_path)
    ctx.log.info("修改成：1001错误返回")
    ctx.log.info("修改前：\n")
    ctx.log.info(flow.response.text)
    flow.response.set_text(json.dumps({"result":"1001","message":"服务异常"}))#修改，使用set_text不用转码
    ctx.log.info("修改后：\n")
    ctx.log.info(flow.response.text)
    ctx.log.info("#"*50)
elif  flow.request.host in  host_list:#host_list 域名列表，作为全局变量，公司有多个域名，也隐藏
    ctx.log.info("response= "+flow.response.text)

应用
   移动app测试中，为了测试app的容错能力，在不改动数据库或者折腾服务器的情况下，脚本修改request或者response内容【这里也可以选择第三方工具，如fiddler同样支持，看个人需求】，查看app的表现；亦或是根据接口定义检查app的接口请求情况

作者：小蜗牛的成长
链接：https://www.jianshu.com/p/a495cc016682
來源：简书
简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。