diff options
Diffstat (limited to 'libmproxy/protocol2/http.py')
| -rw-r--r-- | libmproxy/protocol2/http.py | 174 |
1 files changed, 150 insertions, 24 deletions
diff --git a/libmproxy/protocol2/http.py b/libmproxy/protocol2/http.py index 54cc9dbc..44ebf6a8 100644 --- a/libmproxy/protocol2/http.py +++ b/libmproxy/protocol2/http.py @@ -1,17 +1,22 @@ from __future__ import (absolute_import, print_function, division) +from .. import version +from ..exceptions import InvalidCredentials, HttpException, ProtocolException from .layer import Layer, ServerConnectionMixin -from libmproxy import version -from libmproxy.exceptions import InvalidCredentials +from .messages import ChangeServer, Connect, Reconnect +from .http_proxy import HttpProxy, HttpUpstreamProxy +from libmproxy.protocol import KILL + from libmproxy.protocol.http import HTTPFlow -from libmproxy.protocol.http_wrappers import HTTPResponse +from libmproxy.protocol.http_wrappers import HTTPResponse, HTTPRequest from libmproxy.protocol2.http_protocol_mock import HTTP1 +from libmproxy.protocol2.tls import TlsLayer from netlib import tcp from netlib.http import status_codes from netlib import odict -def send_http_error_response(status_code, message, headers=odict.ODictCaseless()): +def make_error_response(status_code, message, headers=None): response = status_codes.RESPONSES.get(status_code, "Unknown") body = """ <html> @@ -22,21 +27,40 @@ def send_http_error_response(status_code, message, headers=odict.ODictCaseless() </html> """.strip() % (status_code, response, message) + if not headers: + headers = odict.ODictCaseless() headers["Server"] = [version.NAMEVERSION] headers["Connection"] = ["close"] headers["Content-Length"] = [len(body)] headers["Content-Type"] = ["text/html"] - resp = HTTPResponse( - (1, 1), # if HTTP/2 is used, this value is ignored anyway + return HTTPResponse( + (1, 1), # FIXME: Should be a string. status_code, response, headers, body, ) - protocol = self.c.client_conn.protocol or http1.HTTP1Protocol(self.c.client_conn) - self.c.client_conn.send(protocol.assemble(resp)) +def make_connect_request(address): + return HTTPRequest( + "authority", "CONNECT", None, address.host, address.port, None, (1,1), + odict.ODictCaseless(), "" + ) + +def make_connect_response(httpversion): + headers = odict.ODictCaseless([ + ["Content-Length", "0"], + ["Proxy-Agent", version.NAMEVERSION] + ]) + return HTTPResponse( + httpversion, + 200, + "Connection established", + headers, + "", + ) + class HttpLayer(Layer, ServerConnectionMixin): """ @@ -45,11 +69,16 @@ class HttpLayer(Layer, ServerConnectionMixin): def __init__(self, ctx): super(HttpLayer, self).__init__(ctx) - self.skip_authentication = False + if any(isinstance(l, HttpProxy) for l in self.layers): + self.mode = "regular" + elif any(isinstance(l, HttpUpstreamProxy) for l in self.layers): + self.mode = "upstream" + else: + # also includes socks or reverse mode, which are handled similarly on this layer. + self.mode = "transparent" def __call__(self): while True: - flow = HTTPFlow(self.client_conn, self.server_conn) try: request = HTTP1.read_request( self.client_conn, @@ -62,29 +91,126 @@ class HttpLayer(Layer, ServerConnectionMixin): self.c.log("request", "debug", [repr(request)]) - self.check_authentication(request) + # Handle Proxy Authentication + self.authenticate(request) + # Regular Proxy Mode: Handle CONNECT if self.mode == "regular" and request.form_in == "authority": - raise NotImplementedError - + self.server_address = (request.host, request.port) + self.send_to_client(make_connect_response(request.httpversion)) + layer = self.ctx.next_layer(self) + for message in layer(): + if not self._handle_server_message(message): + yield message + return + # Make sure that the incoming request matches our expectations + self.validate_request(request) - ret = self.process_request(flow, request) - if ret is True: - continue - if ret is False: + flow = HTTPFlow(self.client_conn, self.server_conn) + flow.request = request + if not self.process_request_hook(flow): + self.log("Connection killed", "info") return - def check_authentication(self, request): + if not flow.response: + self.establish_server_connection(flow) + + 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: + flow.request.host = self.ctx.server_address.host + flow.request.port = self.ctx.server_address.port + flow.request.scheme = self.server_conn.tls_established + + # TODO: Expose ChangeServer functionality to inline scripts somehow? (yield_from_callback?) + request_reply = self.c.channel.ask("request", flow) + if request_reply is None or request_reply == KILL: + return False + 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 self.server_address != address or tls != self.server_address.ssl_established: + yield ChangeServer(address, tls, address.host) + # Establish connection is neccessary. + if not self.server_conn: + yield Connect() + + # ChangeServer is not guaranteed to work with TLS: + # If there's not TlsLayer below which could catch the exception, + # TLS will not be established. + if tls and not self.server_conn.tls_established: + raise ProtocolException("Cannot upgrade to SSL, no TLS layer on the protocol stack.") + + else: + if tls: + raise HttpException("Cannot change scheme in upstream proxy mode.") + """ + # This is a very ugly (untested) workaround to solve a very ugly problem. + # FIXME: Check if connected first. + if self.server_conn.tls_established and not ssl: + yield Reconnect() + elif ssl and not hasattr(self, "connected_to") or self.connected_to != address: + if self.server_conn.tls_established: + yield Reconnect() + + self.send_to_server(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": + self.send_resplonse(make_error_response(400, "Invalid request scheme: %s" % request.scheme)) + raise HttpException("Invalid request scheme: %s" % request.scheme) + + expected_request_forms = { + "regular": ("absolute",), # an authority request would already be handled. + "upstream": ("authority", "absolute"), + "transparent": ("regular",) + } + + 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 + ) + self.send_to_client(make_error_response(400, err_message)) + raise HttpException(err_message) + + def authenticate(self, request): if self.config.authenticator: if self.config.authenticator.authenticate(request.headers): self.config.authenticator.clean(request.headers) else: - self.send_error() + self.send_to_client(make_error_response( + 407, + "Proxy Authentication Required", + self.config.authenticator.auth_challenge_headers() + )) raise InvalidCredentials("Proxy Authentication Required") - raise http.HttpAuthenticationError( - self.c.config.authenticator.auth_challenge_headers()) - return request.headers - def send_error(self, code, message, headers): - pass
\ No newline at end of file + def send_to_server(self, message): + self.server_conn.wfile.wrie(message) + + def send_to_client(self, message): + # FIXME + # - possibly do some http2 stuff here + # - fix message assembly. + self.client_conn.wfile.write(message) |