试图用aiohttp建立代理服务器

Question

我想用aiohttp编写一个转发http代理服务器，我目前已经使用http协议工作，但希望它能够与https协作（无需解密）。

import asyncio 
from aiohttp import web, ClientSession 

loop = asyncio.get_event_loop() 


async def handler(server_request): 
    if server_request.method == "CONNECT": 
     print(await server_request.read()) 
    else: 
     async with ClientSession() as session: 
      async with session.request(server_request.method, server_request.raw_path) as request: 
       response = web.StreamResponse(status=200, 
               reason='OK', 
               headers={'Content-Type': 'text/html'}) 
       await response.prepare(server_request) 
       while True: 
        chunk = await request.content.read() 
        if not chunk: 
         break 
        response.write(chunk) 
       return response 


server = web.Server(handler) 
loop.run_until_complete(loop.create_server(server, "0.0.0.0", 8080)) 
try: 

    loop.run_forever() 
except KeyboardInterrupt: 
    loop.close() 
    pass 

我得，我需要得到的原始体隧道发送到目的地，但似乎无法访问它

如果我尝试读取我得到一个点例外：

b'' 
Unhandled exception 
Traceback (most recent call last): 
    File "/usr/local/lib/python3.6/dist-packages/aiohttp/web_protocol.py", line 434, in start 
    yield from resp.prepare(request) 
AttributeError: 'NoneType' object has no attribute 'prepare' 

Answer 1

在HTTPS代理的基本思想是行动象流代理，我们在那里读取原始数据，并把原始数据到目的地。不幸的是，在浏览aiohttp后，我找不到任何有助于达到相同的内容，因此您需要我们基本的asyncio。

下面的代码段示出了HTTPS部分

if head[0] == 'CONNECT': # https proxy 
    try: 
     logger.info('%sBYPASSING <%s %s> (SSL connection)' % 
      ('[%s] ' % ident if verbose >= 1 else '', head[0], head[1])) 
     m = REGEX_HOST.search(head[1]) 
     host = m.group(1) 
     port = int(m.group(2)) 
     req_reader, req_writer = yield from asyncio.open_connection(host, port, ssl=False, loop=loop) 
     client_writer.write(b'HTTP/1.1 200 Connection established\r\n\r\n') 
     @asyncio.coroutine 
     def relay_stream(reader, writer): 
      try: 
       while True: 
        line = yield from reader.read(1024) 
        if len(line) == 0: 
         break 
        writer.write(line) 
      except: 
       print_exc() 
     tasks = [ 
      asyncio.async(relay_stream(client_reader, req_writer), loop=loop), 
      asyncio.async(relay_stream(req_reader, client_writer), loop=loop), 
     ] 
     yield from asyncio.wait(tasks, loop=loop) 
    except: 
     print_exc() 
    finally: 
     return 

完整PROXY代码背后的主要逻辑是如下面

#!/usr/bin/env python3 

VERSION = "v0.2.0" 

""" 
Copyright (c) 2013 devunt 

Permission is hereby granted, free of charge, to any person 
obtaining a copy of this software and associated documentation 
files (the "Software"), to deal in the Software without 
restriction, including without limitation the rights to use, 
copy, modify, merge, publish, distribute, sublicense, and/or sell 
copies of the Software, and to permit persons to whom the 
Software is furnished to do so, subject to the following 
conditions: 

The above copyright notice and this permission notice shall be 
included in all copies or substantial portions of the Software. 

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 
OTHER DEALINGS IN THE SOFTWARE. 
""" 

import sys 
if sys.version_info < (3, 4): 
    print('Error: You need python 3.4.0 or above.') 
    exit(1) 

from argparse import ArgumentParser 
from socket import TCP_NODELAY 
from time import time 
from traceback import print_exc 
import asyncio 
import logging 
import random 
import functools 
import re 


REGEX_HOST   = re.compile(r'(.+?):([0-9]{1,5})') 
REGEX_CONTENT_LENGTH = re.compile(r'\r\nContent-Length: ([0-9]+)\r\n', re.IGNORECASE) 
REGEX_CONNECTION  = re.compile(r'\r\nConnection: (.+)\r\n', re.IGNORECASE) 

clients = {} 

logging.basicConfig(level=logging.INFO, format='[%(asctime)s] {%(levelname)s} %(message)s') 
logging.getLogger('asyncio').setLevel(logging.CRITICAL) 
logger = logging.getLogger('warp') 
verbose = 0 


def accept_client(client_reader, client_writer, *, loop=None): 
    ident = hex(id(client_reader))[-6:] 
    task = asyncio.async(process_warp(client_reader, client_writer, loop=loop), loop=loop) 
    clients[task] = (client_reader, client_writer) 
    started_time = time() 

    def client_done(task): 
     del clients[task] 
     client_writer.close() 
     logger.debug('[%s] Connection closed (took %.5f seconds)' % (ident, time() - started_time)) 

    logger.debug('[%s] Connection started' % ident) 
    task.add_done_callback(client_done) 


@asyncio.coroutine 
def process_warp(client_reader, client_writer, *, loop=None): 
    ident = str(hex(id(client_reader)))[-6:] 
    header = '' 
    payload = b'' 
    try: 
     RECV_MAX_RETRY = 3 
     recvRetry = 0 
     while True: 
      line = yield from client_reader.readline() 
      if not line: 
       if len(header) == 0 and recvRetry < RECV_MAX_RETRY: 
        # handle the case when the client make connection but sending data is delayed for some reasons 
        recvRetry += 1 
        yield from asyncio.sleep(0.2, loop=loop) 
        continue 
       else: 
        break 
      if line == b'\r\n': 
       break 
      if line != b'': 
       header += line.decode() 

     m = REGEX_CONTENT_LENGTH.search(header) 
     if m: 
      cl = int(m.group(1)) 
      while (len(payload) < cl): 
       payload += yield from client_reader.read(1024) 
    except: 
     print_exc() 

    if len(header) == 0: 
     logger.debug('[%s] !!! Task reject (empty request)' % ident) 
     return 

    req = header.split('\r\n')[:-1] 
    if len(req) < 4: 
     logger.debug('[%s] !!! Task reject (invalid request)' % ident) 
     return 
    head = req[0].split(' ') 
    if head[0] == 'CONNECT': # https proxy 
     try: 
      logger.info('%sBYPASSING <%s %s> (SSL connection)' % 
       ('[%s] ' % ident if verbose >= 1 else '', head[0], head[1])) 
      m = REGEX_HOST.search(head[1]) 
      host = m.group(1) 
      port = int(m.group(2)) 
      req_reader, req_writer = yield from asyncio.open_connection(host, port, ssl=False, loop=loop) 
      client_writer.write(b'HTTP/1.1 200 Connection established\r\n\r\n') 
      @asyncio.coroutine 
      def relay_stream(reader, writer): 
       try: 
        while True: 
         line = yield from reader.read(1024) 
         if len(line) == 0: 
          break 
         writer.write(line) 
       except: 
        print_exc() 
      tasks = [ 
       asyncio.async(relay_stream(client_reader, req_writer), loop=loop), 
       asyncio.async(relay_stream(req_reader, client_writer), loop=loop), 
      ] 
      yield from asyncio.wait(tasks, loop=loop) 
     except: 
      print_exc() 
     finally: 
      return 
    phost = False 
    sreq = [] 
    sreqHeaderEndIndex = 0 
    for line in req[1:]: 
     headerNameAndValue = line.split(': ', 1) 
     if len(headerNameAndValue) == 2: 
      headerName, headerValue = headerNameAndValue 
     else: 
      headerName, headerValue = headerNameAndValue[0], None 

     if headerName.lower() == "host": 
      phost = headerValue 
     elif headerName.lower() == "connection": 
      if headerValue.lower() in ('keep-alive', 'persist'): 
       # current version of this program does not support the HTTP keep-alive feature 
       sreq.append("Connection: close") 
      else: 
       sreq.append(line) 
     elif headerName.lower() != 'proxy-connection': 
      sreq.append(line) 
      if len(line) == 0 and sreqHeaderEndIndex == 0: 
       sreqHeaderEndIndex = len(sreq) - 1 
    if sreqHeaderEndIndex == 0: 
     sreqHeaderEndIndex = len(sreq) 

    m = REGEX_CONNECTION.search(header) 
    if not m: 
     sreq.insert(sreqHeaderEndIndex, "Connection: close") 

    if not phost: 
     phost = '127.0.0.1' 
    path = head[1][len(phost)+7:] 

    logger.info('%sWARPING <%s %s>' % ('[%s] ' % ident if verbose >= 1 else '', head[0], head[1])) 

    new_head = ' '.join([head[0], path, head[2]]) 

    m = REGEX_HOST.search(phost) 
    if m: 
     host = m.group(1) 
     port = int(m.group(2)) 
    else: 
     host = phost 
     port = 80 

    try: 
     req_reader, req_writer = yield from asyncio.open_connection(host, port, flags=TCP_NODELAY, loop=loop) 
     req_writer.write(('%s\r\n' % new_head).encode()) 
     yield from req_writer.drain() 
     yield from asyncio.sleep(0.2, loop=loop) 

     def generate_dummyheaders(): 
      def generate_rndstrs(strings, length): 
       return ''.join(random.choice(strings) for _ in range(length)) 
      import string 
      return ['X-%s: %s\r\n' % (generate_rndstrs(string.ascii_uppercase, 16), 
       generate_rndstrs(string.ascii_letters + string.digits, 128)) for _ in range(32)] 

     req_writer.writelines(list(map(lambda x: x.encode(), generate_dummyheaders()))) 
     yield from req_writer.drain() 

     req_writer.write(b'Host: ') 
     yield from req_writer.drain() 
     def feed_phost(phost): 
      i = 1 
      while phost: 
       yield random.randrange(2, 4), phost[:i] 
       phost = phost[i:] 
       i = random.randrange(2, 5) 
     for delay, c in feed_phost(phost): 
      yield from asyncio.sleep(delay/10.0, loop=loop) 
      req_writer.write(c.encode()) 
      yield from req_writer.drain() 
     req_writer.write(b'\r\n') 
     req_writer.writelines(list(map(lambda x: (x + '\r\n').encode(), sreq))) 
     req_writer.write(b'\r\n') 
     if payload != b'': 
      req_writer.write(payload) 
      req_writer.write(b'\r\n') 
     yield from req_writer.drain() 

     try: 
      while True: 
       buf = yield from req_reader.read(1024) 
       if len(buf) == 0: 
        break 
       client_writer.write(buf) 
     except: 
      print_exc() 

    except: 
     print_exc() 

    client_writer.close() 


@asyncio.coroutine 
def start_warp_server(host, port, *, loop = None): 
    try: 
     accept = functools.partial(accept_client, loop=loop) 
     server = yield from asyncio.start_server(accept, host=host, port=port, loop=loop) 
    except OSError as ex: 
     logger.critical('!!! Failed to bind server at [%s:%d]: %s' % (host, port, ex.args[1])) 
     raise 
    else: 
     logger.info('Server bound at [%s:%d].' % (host, port)) 
     return server 


def main(): 
    """CLI frontend function. It takes command line options e.g. host, 
    port and provides `--help` message. 

    """ 
    parser = ArgumentParser(description='Simple HTTP transparent proxy') 
    parser.add_argument('-H', '--host', default='127.0.0.1', 
         help='Host to listen [default: %(default)s]') 
    parser.add_argument('-p', '--port', type=int, default=8800, 
         help='Port to listen [default: %(default)d]') 
    parser.add_argument('-v', '--verbose', action='count', default=0, 
         help='Print verbose') 
    args = parser.parse_args() 
    if not (1 <= args.port <= 65535): 
     parser.error('port must be 1-65535') 
    if args.verbose >= 3: 
     parser.error('verbose level must be 1-2') 
    if args.verbose >= 1: 
     logger.setLevel(logging.DEBUG) 
    if args.verbose >= 2: 
     logging.getLogger('warp').setLevel(logging.DEBUG) 
     logging.getLogger('asyncio').setLevel(logging.DEBUG) 
    global verbose 
    verbose = args.verbose 
    loop = asyncio.get_event_loop() 
    try: 
     loop.run_until_complete(start_warp_server(args.host, args.port)) 
     loop.run_forever() 
    except OSError: 
     pass 
    except KeyboardInterrupt: 
     print('bye') 
    finally: 
     loop.close() 


if __name__ == '__main__': 
    exit(main()) 

PS：代码已经从https://github.com/devunt/warp服用。完整的代码发布在这里，以便如果链接将来无效，答案仍然有效。