mirror of
https://github.com/Grasscutters/mitmproxy.git
synced 2024-11-24 00:31:33 +00:00
390 lines
14 KiB
Python
390 lines
14 KiB
Python
from __future__ import (absolute_import, print_function, division)
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from .. import version
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from ..exceptions import InvalidCredentials, HttpException, ProtocolException
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from .layer import Layer
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from libmproxy import utils
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from libmproxy.proxy.connection import ServerConnection
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from .messages import SetServer, Connect, Reconnect, Kill
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from libmproxy.protocol import KILL
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from libmproxy.protocol.http import HTTPFlow
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from libmproxy.protocol.http_wrappers import HTTPResponse, HTTPRequest
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from libmproxy.protocol2.http_protocol_mock import HTTP1
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from netlib import tcp
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from netlib.http import status_codes, http1, HttpErrorConnClosed
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from netlib.http.semantics import CONTENT_MISSING
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from netlib import odict
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from netlib.tcp import NetLibError, Address
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def make_error_response(status_code, message, headers=None):
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response = status_codes.RESPONSES.get(status_code, "Unknown")
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body = """
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<html>
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<head>
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<title>%d %s</title>
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</head>
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<body>%s</body>
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</html>
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""".strip() % (status_code, response, message)
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if not headers:
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headers = odict.ODictCaseless()
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headers["Server"] = [version.NAMEVERSION]
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headers["Connection"] = ["close"]
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headers["Content-Length"] = [len(body)]
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headers["Content-Type"] = ["text/html"]
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return HTTPResponse(
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(1, 1), # FIXME: Should be a string.
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status_code,
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response,
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headers,
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body,
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)
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def make_connect_request(address):
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address = Address.wrap(address)
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return HTTPRequest(
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"authority", "CONNECT", None, address.host, address.port, None, (1, 1),
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odict.ODictCaseless(), ""
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)
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def make_connect_response(httpversion):
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headers = odict.ODictCaseless([
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["Content-Length", "0"],
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["Proxy-Agent", version.NAMEVERSION]
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])
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return HTTPResponse(
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httpversion,
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200,
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"Connection established",
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headers,
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"",
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)
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class ConnectServerConnection(object):
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"""
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"Fake" ServerConnection to represent state after a CONNECT request to an upstream proxy.
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"""
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def __init__(self, address, ctx):
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self.address = tcp.Address.wrap(address)
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self._ctx = ctx
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@property
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def via(self):
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return self._ctx.server_conn
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def __getattr__(self, item):
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return getattr(self.via, item)
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class HttpLayer(Layer):
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"""
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HTTP 1 Layer
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"""
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def __init__(self, ctx, mode):
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super(HttpLayer, self).__init__(ctx)
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self.mode = mode
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def __call__(self):
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while True:
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try:
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try:
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request = HTTP1.read_request(
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self.client_conn,
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body_size_limit=self.config.body_size_limit
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)
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except tcp.NetLibError:
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# don't throw an error for disconnects that happen
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# before/between requests.
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return
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self.log("request", "debug", [repr(request)])
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# Handle Proxy Authentication
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self.authenticate(request)
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# Regular Proxy Mode: Handle CONNECT
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if self.mode == "regular" and request.form_in == "authority":
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for message in self.handle_regular_mode_connect(request):
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yield message
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return
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# Make sure that the incoming request matches our expectations
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self.validate_request(request)
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flow = HTTPFlow(self.client_conn, self.server_conn)
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flow.request = request
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for message in self.process_request_hook(flow):
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yield message
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if not flow.response:
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for message in self.establish_server_connection(flow):
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yield message
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for message in self.get_response_from_server(flow):
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yield message
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self.send_response_to_client(flow)
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if self.check_close_connection(flow):
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return
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# Upstream Proxy Mode: Handle CONNECT
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if flow.request.form_in == "authority" and flow.response.code == 200:
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for message in self.handle_upstream_mode_connect(flow.request.copy()):
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yield message
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return
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except (HttpErrorConnClosed, NetLibError) as e:
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make_error_response(502, repr(e))
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raise ProtocolException(repr(e), e)
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def handle_regular_mode_connect(self, request):
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yield SetServer((request.host, request.port), False, None)
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self.send_to_client(make_connect_response(request.httpversion))
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layer = self.ctx.next_layer(self)
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for message in layer():
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yield message
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def handle_upstream_mode_connect(self, connect_request):
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layer = self.ctx.next_layer(self)
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self.server_conn = ConnectServerConnection((connect_request.host, connect_request.port), self.ctx)
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for message in layer():
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if message == Connect:
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if not self.server_conn:
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yield message
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self.send_to_server(connect_request)
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else:
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pass # swallow the message
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elif message == Reconnect:
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yield message
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self.send_to_server(connect_request)
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elif message == SetServer:
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if message.depth == 1:
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if self.ctx.server_conn:
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yield Reconnect()
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connect_request.host = message.address.host
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connect_request.port = message.address.port
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self.server_conn.address = message.address
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else:
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message.depth -= 1
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yield message
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else:
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yield message
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def check_close_connection(self, flow):
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"""
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Checks if the connection should be closed depending on the HTTP
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semantics. Returns True, if so.
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"""
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# TODO: add logic for HTTP/2
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close_connection = (
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http1.HTTP1Protocol.connection_close(
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flow.request.httpversion,
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flow.request.headers
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) or http1.HTTP1Protocol.connection_close(
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flow.response.httpversion,
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flow.response.headers
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) or http1.HTTP1Protocol.expected_http_body_size(
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flow.response.headers,
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False,
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flow.request.method,
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flow.response.code) == -1
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)
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if flow.request.form_in == "authority" and flow.response.code == 200:
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# Workaround for
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# https://github.com/mitmproxy/mitmproxy/issues/313: Some
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# proxies (e.g. Charles) send a CONNECT response with HTTP/1.0
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# and no Content-Length header
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return False
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return close_connection
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def send_response_to_client(self, flow):
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if not flow.response.stream:
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# no streaming:
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# we already received the full response from the server and can
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# send it to the client straight away.
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self.send_to_client(flow.response)
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else:
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# streaming:
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# First send the headers and then transfer the response
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# incrementally:
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h = HTTP1._assemble_response_first_line(flow.response)
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self.send_to_client(h + "\r\n")
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h = HTTP1._assemble_response_headers(flow.response, preserve_transfer_encoding=True)
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self.send_to_client(h + "\r\n")
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chunks = HTTP1.read_http_body_chunked(
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flow.response.headers,
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self.config.body_size_limit,
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flow.request.method,
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flow.response.code,
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False,
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4096
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)
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if callable(flow.response.stream):
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chunks = flow.response.stream(chunks)
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for chunk in chunks:
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for part in chunk:
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self.send_to_client(part)
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self.client_conn.wfile.flush()
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flow.response.timestamp_end = utils.timestamp()
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def get_response_from_server(self, flow):
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# TODO: Add second attempt.
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self.send_to_server(flow.request)
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flow.response = HTTP1.read_response(
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self.server_conn,
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flow.request.method,
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body_size_limit=self.config.body_size_limit,
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include_body=False,
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)
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# call the appropriate script hook - this is an opportunity for an
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# inline script to set flow.stream = True
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flow = self.channel.ask("responseheaders", flow)
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if flow is None or flow == KILL:
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yield Kill()
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if flow.response.stream:
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flow.response.content = CONTENT_MISSING
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else:
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flow.response.content = HTTP1.read_http_body(
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self.server_conn,
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flow.response.headers,
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self.config.body_size_limit,
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flow.request.method,
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flow.response.code,
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False
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)
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flow.response.timestamp_end = utils.timestamp()
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# no further manipulation of self.server_conn beyond this point
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# we can safely set it as the final attribute value here.
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flow.server_conn = self.server_conn
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self.log(
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"response",
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"debug",
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[repr(flow.response)]
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)
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response_reply = self.channel.ask("response", flow)
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if response_reply is None or response_reply == KILL:
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yield Kill()
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def process_request_hook(self, flow):
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# Determine .scheme, .host and .port attributes for inline scripts.
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# For absolute-form requests, they are directly given in the request.
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# For authority-form requests, we only need to determine the request scheme.
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# For relative-form requests, we need to determine host and port as
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# well.
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if self.mode == "regular":
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pass # only absolute-form at this point, nothing to do here.
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elif self.mode == "upstream":
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if flow.request.form_in == "authority":
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flow.request.scheme = "http" # pseudo value
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else:
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flow.request.host = self.ctx.server_conn.address.host
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flow.request.port = self.ctx.server_conn.address.port
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flow.request.scheme = "https" if self.server_conn.tls_established else "http"
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# TODO: Expose SetServer functionality to inline scripts somehow? (yield_from_callback?)
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request_reply = self.channel.ask("request", flow)
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if request_reply is None or request_reply == KILL:
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yield Kill()
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if isinstance(request_reply, HTTPResponse):
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flow.response = request_reply
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return
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def establish_server_connection(self, flow):
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address = tcp.Address((flow.request.host, flow.request.port))
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tls = (flow.request.scheme == "https")
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if self.mode == "regular" or self.mode == "transparent":
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# If there's an existing connection that doesn't match our expectations, kill it.
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if address != self.server_conn.address or tls != self.server_conn.ssl_established:
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yield SetServer(address, tls, address.host)
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# Establish connection is neccessary.
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if not self.server_conn:
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yield Connect()
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# SetServer is not guaranteed to work with TLS:
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# If there's not TlsLayer below which could catch the exception,
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# TLS will not be established.
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if tls and not self.server_conn.tls_established:
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raise ProtocolException("Cannot upgrade to SSL, no TLS layer on the protocol stack.")
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else:
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if not self.server_conn:
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yield Connect()
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if tls:
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raise HttpException("Cannot change scheme in upstream proxy mode.")
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"""
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# This is a very ugly (untested) workaround to solve a very ugly problem.
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if self.server_conn and self.server_conn.tls_established and not ssl:
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yield Reconnect()
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elif ssl and not hasattr(self, "connected_to") or self.connected_to != address:
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if self.server_conn.tls_established:
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yield Reconnect()
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self.send_to_server(make_connect_request(address))
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tls_layer = TlsLayer(self, False, True)
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tls_layer._establish_tls_with_server()
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"""
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def validate_request(self, request):
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if request.form_in == "absolute" and request.scheme != "http":
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self.send_resplonse(make_error_response(400, "Invalid request scheme: %s" % request.scheme))
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raise HttpException("Invalid request scheme: %s" % request.scheme)
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expected_request_forms = {
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"regular": ("absolute",), # an authority request would already be handled.
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"upstream": ("authority", "absolute"),
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"transparent": ("relative",)
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}
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allowed_request_forms = expected_request_forms[self.mode]
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if request.form_in not in allowed_request_forms:
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err_message = "Invalid HTTP request form (expected: %s, got: %s)" % (
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" or ".join(allowed_request_forms), request.form_in
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)
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self.send_to_client(make_error_response(400, err_message))
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raise HttpException(err_message)
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if self.mode == "regular":
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request.form_out = "relative"
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def authenticate(self, request):
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if self.config.authenticator:
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if self.config.authenticator.authenticate(request.headers):
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self.config.authenticator.clean(request.headers)
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else:
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self.send_to_client(make_error_response(
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407,
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"Proxy Authentication Required",
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self.config.authenticator.auth_challenge_headers()
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))
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raise InvalidCredentials("Proxy Authentication Required")
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def send_to_server(self, message):
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self.server_conn.send(HTTP1.assemble(message))
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def send_to_client(self, message):
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# FIXME
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# - possibly do some http2 stuff here
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self.client_conn.send(HTTP1.assemble(message))
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