mirror of
https://github.com/Grasscutters/mitmproxy.git
synced 2024-11-24 00:31:33 +00:00
411 lines
15 KiB
Python
411 lines
15 KiB
Python
from __future__ import (absolute_import, print_function, division)
|
|
|
|
import sys
|
|
import traceback
|
|
import six
|
|
|
|
from netlib import tcp
|
|
from netlib.exceptions import HttpException, HttpReadDisconnect, NetlibException
|
|
from netlib.http import Headers, CONTENT_MISSING
|
|
|
|
from h2.exceptions import H2Error
|
|
|
|
from .. import utils
|
|
from ..exceptions import HttpProtocolException, ProtocolException
|
|
from ..models import (
|
|
HTTPFlow,
|
|
HTTPResponse,
|
|
make_error_response,
|
|
make_connect_response,
|
|
Error,
|
|
expect_continue_response
|
|
)
|
|
|
|
from .base import Layer, Kill
|
|
|
|
class _HttpTransmissionLayer(Layer):
|
|
def read_request(self):
|
|
raise NotImplementedError()
|
|
|
|
def read_request_body(self, request):
|
|
raise NotImplementedError()
|
|
|
|
def send_request(self, request):
|
|
raise NotImplementedError()
|
|
|
|
def read_response(self, request):
|
|
response = self.read_response_headers()
|
|
response.data.content = b"".join(
|
|
self.read_response_body(request, response)
|
|
)
|
|
return response
|
|
|
|
def read_response_headers(self):
|
|
raise NotImplementedError()
|
|
|
|
def read_response_body(self, request, response):
|
|
raise NotImplementedError()
|
|
yield "this is a generator" # pragma: no cover
|
|
|
|
def send_response(self, response):
|
|
if response.content == CONTENT_MISSING:
|
|
raise HttpException("Cannot assemble flow with CONTENT_MISSING")
|
|
self.send_response_headers(response)
|
|
self.send_response_body(response, [response.content])
|
|
|
|
def send_response_headers(self, response):
|
|
raise NotImplementedError()
|
|
|
|
def send_response_body(self, response, chunks):
|
|
raise NotImplementedError()
|
|
|
|
def check_close_connection(self, flow):
|
|
raise NotImplementedError()
|
|
|
|
|
|
class ConnectServerConnection(object):
|
|
|
|
"""
|
|
"Fake" ServerConnection to represent state after a CONNECT request to an upstream proxy.
|
|
"""
|
|
|
|
def __init__(self, address, ctx):
|
|
self.address = tcp.Address.wrap(address)
|
|
self._ctx = ctx
|
|
|
|
@property
|
|
def via(self):
|
|
return self._ctx.server_conn
|
|
|
|
def __getattr__(self, item):
|
|
return getattr(self.via, item)
|
|
|
|
def __nonzero__(self):
|
|
return bool(self.via)
|
|
|
|
|
|
class UpstreamConnectLayer(Layer):
|
|
|
|
def __init__(self, ctx, connect_request):
|
|
super(UpstreamConnectLayer, self).__init__(ctx)
|
|
self.connect_request = connect_request
|
|
self.server_conn = ConnectServerConnection(
|
|
(connect_request.host, connect_request.port),
|
|
self.ctx
|
|
)
|
|
|
|
def __call__(self):
|
|
layer = self.ctx.next_layer(self)
|
|
layer()
|
|
|
|
def _send_connect_request(self):
|
|
self.send_request(self.connect_request)
|
|
resp = self.read_response(self.connect_request)
|
|
if resp.status_code != 200:
|
|
raise ProtocolException("Reconnect: Upstream server refuses CONNECT request")
|
|
|
|
def connect(self):
|
|
if not self.server_conn:
|
|
self.ctx.connect()
|
|
self._send_connect_request()
|
|
else:
|
|
pass # swallow the message
|
|
|
|
def change_upstream_proxy_server(self, address):
|
|
if address != self.server_conn.via.address:
|
|
self.ctx.set_server(address)
|
|
|
|
def set_server(self, address, server_tls=None, sni=None):
|
|
if self.ctx.server_conn:
|
|
self.ctx.disconnect()
|
|
address = tcp.Address.wrap(address)
|
|
self.connect_request.host = address.host
|
|
self.connect_request.port = address.port
|
|
self.server_conn.address = address
|
|
|
|
if server_tls:
|
|
raise ProtocolException(
|
|
"Cannot upgrade to TLS, no TLS layer on the protocol stack."
|
|
)
|
|
|
|
|
|
class HttpLayer(Layer):
|
|
|
|
def __init__(self, ctx, mode):
|
|
super(HttpLayer, self).__init__(ctx)
|
|
self.mode = mode
|
|
self.__original_server_conn = None
|
|
"Contains the original destination in transparent mode, which needs to be restored"
|
|
"if an inline script modified the target server for a single http request"
|
|
|
|
def __call__(self):
|
|
if self.mode == "transparent":
|
|
self.__original_server_conn = self.server_conn
|
|
while True:
|
|
try:
|
|
request = self.get_request_from_client()
|
|
self.log("request", "debug", [repr(request)])
|
|
|
|
# Handle Proxy Authentication
|
|
# Proxy Authentication conceptually does not work in transparent mode.
|
|
# We catch this misconfiguration on startup. Here, we sort out requests
|
|
# after a successful CONNECT request (which do not need to be validated anymore)
|
|
if self.mode != "transparent" and not self.authenticate(request):
|
|
return
|
|
|
|
# Make sure that the incoming request matches our expectations
|
|
self.validate_request(request)
|
|
|
|
# Regular Proxy Mode: Handle CONNECT
|
|
if self.mode == "regular" and request.form_in == "authority":
|
|
self.handle_regular_mode_connect(request)
|
|
return
|
|
|
|
except HttpReadDisconnect:
|
|
# don't throw an error for disconnects that happen before/between requests.
|
|
return
|
|
except NetlibException as e:
|
|
self.send_error_response(400, repr(e))
|
|
six.reraise(ProtocolException, ProtocolException(
|
|
"Error in HTTP connection: %s" % repr(e)), sys.exc_info()[2])
|
|
|
|
try:
|
|
flow = HTTPFlow(self.client_conn, self.server_conn, live=self)
|
|
flow.request = request
|
|
self.process_request_hook(flow)
|
|
|
|
if not flow.response:
|
|
self.establish_server_connection(flow)
|
|
self.get_response_from_server(flow)
|
|
else:
|
|
# response was set by an inline script.
|
|
# we now need to emulate the responseheaders hook.
|
|
flow = self.channel.ask("responseheaders", flow)
|
|
if flow == Kill:
|
|
raise Kill()
|
|
|
|
self.log("response", "debug", [repr(flow.response)])
|
|
flow = self.channel.ask("response", flow)
|
|
if flow == Kill:
|
|
raise Kill()
|
|
self.send_response_to_client(flow)
|
|
|
|
if self.check_close_connection(flow):
|
|
return
|
|
|
|
# Handle 101 Switching Protocols
|
|
# It may be useful to pass additional args (such as the upgrade header)
|
|
# to next_layer in the future
|
|
if flow.response.status_code == 101:
|
|
layer = self.ctx.next_layer(self)
|
|
layer()
|
|
return
|
|
|
|
# Upstream Proxy Mode: Handle CONNECT
|
|
if flow.request.form_in == "authority" and flow.response.status_code == 200:
|
|
self.handle_upstream_mode_connect(flow.request.copy())
|
|
return
|
|
|
|
except (ProtocolException, NetlibException) as e:
|
|
self.send_error_response(502, repr(e))
|
|
|
|
if not flow.response:
|
|
flow.error = Error(str(e))
|
|
self.channel.ask("error", flow)
|
|
self.log(traceback.format_exc(), "debug")
|
|
return
|
|
else:
|
|
six.reraise(ProtocolException, ProtocolException(
|
|
"Error in HTTP connection: %s" % repr(e)), sys.exc_info()[2])
|
|
finally:
|
|
flow.live = False
|
|
|
|
def get_request_from_client(self):
|
|
request = self.read_request()
|
|
if request.headers.get("expect", "").lower() == "100-continue":
|
|
# TODO: We may have to use send_response_headers for HTTP2 here.
|
|
self.send_response(expect_continue_response)
|
|
request.headers.pop("expect")
|
|
request.body = b"".join(self.read_request_body(request))
|
|
return request
|
|
|
|
def send_error_response(self, code, message):
|
|
try:
|
|
response = make_error_response(code, message)
|
|
self.send_response(response)
|
|
except NetlibException, H2Error:
|
|
pass
|
|
|
|
def change_upstream_proxy_server(self, address):
|
|
# Make set_upstream_proxy_server always available,
|
|
# even if there's no UpstreamConnectLayer
|
|
if address != self.server_conn.address:
|
|
return self.set_server(address)
|
|
|
|
def handle_regular_mode_connect(self, request):
|
|
self.set_server((request.host, request.port))
|
|
self.send_response(make_connect_response(request.http_version))
|
|
layer = self.ctx.next_layer(self)
|
|
layer()
|
|
|
|
def handle_upstream_mode_connect(self, connect_request):
|
|
layer = UpstreamConnectLayer(self, connect_request)
|
|
layer()
|
|
|
|
def send_response_to_client(self, flow):
|
|
if not flow.response.stream:
|
|
# no streaming:
|
|
# we already received the full response from the server and can
|
|
# send it to the client straight away.
|
|
self.send_response(flow.response)
|
|
else:
|
|
# streaming:
|
|
# First send the headers and then transfer the response incrementally
|
|
self.send_response_headers(flow.response)
|
|
chunks = self.read_response_body(
|
|
flow.request,
|
|
flow.response
|
|
)
|
|
if callable(flow.response.stream):
|
|
chunks = flow.response.stream(chunks)
|
|
self.send_response_body(flow.response, chunks)
|
|
flow.response.timestamp_end = utils.timestamp()
|
|
|
|
def get_response_from_server(self, flow):
|
|
def get_response():
|
|
self.send_request(flow.request)
|
|
flow.response = self.read_response_headers()
|
|
|
|
try:
|
|
get_response()
|
|
except NetlibException as v:
|
|
self.log(
|
|
"server communication error: %s" % repr(v),
|
|
level="debug"
|
|
)
|
|
# In any case, we try to reconnect at least once. This is
|
|
# necessary because it might be possible that we already
|
|
# initiated an upstream connection after clientconnect that
|
|
# has already been expired, e.g consider the following event
|
|
# log:
|
|
# > clientconnect (transparent mode destination known)
|
|
# > serverconnect (required for client tls handshake)
|
|
# > read n% of large request
|
|
# > server detects timeout, disconnects
|
|
# > read (100-n)% of large request
|
|
# > send large request upstream
|
|
self.disconnect()
|
|
self.connect()
|
|
get_response()
|
|
|
|
# call the appropriate script hook - this is an opportunity for an
|
|
# inline script to set flow.stream = True
|
|
flow = self.channel.ask("responseheaders", flow)
|
|
if flow == Kill:
|
|
raise Kill()
|
|
|
|
if flow.response.stream:
|
|
flow.response.data.content = CONTENT_MISSING
|
|
else:
|
|
flow.response.data.content = b"".join(self.read_response_body(
|
|
flow.request,
|
|
flow.response
|
|
))
|
|
flow.response.timestamp_end = utils.timestamp()
|
|
|
|
# no further manipulation of self.server_conn beyond this point
|
|
# we can safely set it as the final attribute value here.
|
|
flow.server_conn = self.server_conn
|
|
|
|
def process_request_hook(self, flow):
|
|
# Determine .scheme, .host and .port attributes for inline scripts.
|
|
# For absolute-form requests, they are directly given in the request.
|
|
# For authority-form requests, we only need to determine the request scheme.
|
|
# For relative-form requests, we need to determine host and port as
|
|
# well.
|
|
if self.mode == "regular":
|
|
pass # only absolute-form at this point, nothing to do here.
|
|
elif self.mode == "upstream":
|
|
if flow.request.form_in == "authority":
|
|
flow.request.scheme = "http" # pseudo value
|
|
else:
|
|
# Setting request.host also updates the host header, which we want to preserve
|
|
host_header = flow.request.headers.get("host", None)
|
|
flow.request.host = self.__original_server_conn.address.host
|
|
flow.request.port = self.__original_server_conn.address.port
|
|
if host_header:
|
|
flow.request.headers["host"] = host_header
|
|
# TODO: This does not really work if we change the first request and --no-upstream-cert is enabled
|
|
flow.request.scheme = "https" if self.__original_server_conn.tls_established else "http"
|
|
|
|
request_reply = self.channel.ask("request", flow)
|
|
if request_reply == Kill:
|
|
raise Kill()
|
|
if isinstance(request_reply, HTTPResponse):
|
|
flow.response = request_reply
|
|
return
|
|
|
|
def establish_server_connection(self, flow):
|
|
address = tcp.Address((flow.request.host, flow.request.port))
|
|
tls = (flow.request.scheme == "https")
|
|
|
|
if self.mode == "regular" or self.mode == "transparent":
|
|
# If there's an existing connection that doesn't match our expectations, kill it.
|
|
if address != self.server_conn.address or tls != self.server_conn.tls_established:
|
|
self.set_server(address, tls, address.host)
|
|
# Establish connection is neccessary.
|
|
if not self.server_conn:
|
|
self.connect()
|
|
else:
|
|
if not self.server_conn:
|
|
self.connect()
|
|
if tls:
|
|
raise HttpProtocolException("Cannot change scheme in upstream proxy mode.")
|
|
"""
|
|
# This is a very ugly (untested) workaround to solve a very ugly problem.
|
|
if self.server_conn and self.server_conn.tls_established and not ssl:
|
|
self.disconnect()
|
|
self.connect()
|
|
elif ssl and not hasattr(self, "connected_to") or self.connected_to != address:
|
|
if self.server_conn.tls_established:
|
|
self.disconnect()
|
|
self.connect()
|
|
|
|
self.send_request(make_connect_request(address))
|
|
tls_layer = TlsLayer(self, False, True)
|
|
tls_layer._establish_tls_with_server()
|
|
"""
|
|
|
|
def validate_request(self, request):
|
|
if request.form_in == "absolute" and request.scheme != "http":
|
|
raise HttpException("Invalid request scheme: %s" % request.scheme)
|
|
|
|
expected_request_forms = {
|
|
"regular": ("authority", "absolute",),
|
|
"upstream": ("authority", "absolute"),
|
|
"transparent": ("relative",)
|
|
}
|
|
|
|
allowed_request_forms = expected_request_forms[self.mode]
|
|
if request.form_in not in allowed_request_forms:
|
|
err_message = "Invalid HTTP request form (expected: %s, got: %s)" % (
|
|
" or ".join(allowed_request_forms), request.form_in
|
|
)
|
|
raise HttpException(err_message)
|
|
|
|
if self.mode == "regular" and request.form_in == "absolute":
|
|
request.form_out = "relative"
|
|
|
|
def authenticate(self, request):
|
|
if self.config.authenticator:
|
|
if self.config.authenticator.authenticate(request.headers):
|
|
self.config.authenticator.clean(request.headers)
|
|
else:
|
|
self.send_response(make_error_response(
|
|
407,
|
|
"Proxy Authentication Required",
|
|
Headers(**self.config.authenticator.auth_challenge_headers())
|
|
))
|
|
return False
|
|
return True
|