from __future__ import absolute_import import socket from OpenSSL import SSL from netlib import tcp from .primitives import ProxyServerError, Log, ProxyError from .connection import ClientConnection, ServerConnection from ..protocol.handle import protocol_handler from .. import version class DummyServer: bound = False def __init__(self, config): self.config = config def start_slave(self, *args): pass def shutdown(self): pass class ProxyServer(tcp.TCPServer): allow_reuse_address = True bound = True def __init__(self, config): """ Raises ProxyServerError if there's a startup problem. """ self.config = config try: tcp.TCPServer.__init__(self, (config.host, config.port)) except socket.error, v: raise ProxyServerError('Error starting proxy server: ' + repr(v)) self.channel = None def start_slave(self, klass, channel): slave = klass(channel, self) slave.start() def set_channel(self, channel): self.channel = channel def handle_client_connection(self, conn, client_address): h = ConnectionHandler(self.config, conn, client_address, self, self.channel) h.handle() h.finish() class ConnectionHandler: def __init__(self, config, client_connection, client_address, server, channel): self.config = config """@type: libmproxy.proxy.config.ProxyConfig""" self.client_conn = ClientConnection(client_connection, client_address, server) """@type: libmproxy.proxy.connection.ClientConnection""" self.server_conn = None """@type: libmproxy.proxy.connection.ServerConnection""" self.channel = channel self.conntype = "http" def handle(self): try: self.log("clientconnect", "info") # Can we already identify the target server and connect to it? client_ssl, server_ssl = False, False conn_kwargs = dict() upstream_info = self.config.mode.get_upstream_server(self.client_conn) if upstream_info: self.set_server_address(upstream_info[2:]) client_ssl, server_ssl = upstream_info[:2] if self.config.check_ignore(self.server_conn.address): self.log("Ignore host: %s:%s" % self.server_conn.address(), "info") self.conntype = "tcp" conn_kwargs["log"] = False client_ssl, server_ssl = False, False else: pass # No upstream info from the metadata: upstream info in the protocol (e.g. HTTP absolute-form) self.channel.ask("clientconnect", self) # Check for existing connection: If an inline script already established a # connection, do not apply client_ssl or server_ssl. if self.server_conn and not self.server_conn.connection: self.establish_server_connection() if client_ssl or server_ssl: self.establish_ssl(client=client_ssl, server=server_ssl) if self.config.check_tcp(self.server_conn.address): self.log("Generic TCP mode for host: %s:%s" % self.server_conn.address(), "info") self.conntype = "tcp" # Delegate handling to the protocol handler protocol_handler(self.conntype)(self, **conn_kwargs).handle_messages() self.log("clientdisconnect", "info") self.channel.tell("clientdisconnect", self) except ProxyError as e: protocol_handler(self.conntype)(self, **conn_kwargs).handle_error(e) except Exception: import traceback, sys self.log(traceback.format_exc(), "error") print >> sys.stderr, traceback.format_exc() print >> sys.stderr, "mitmproxy has crashed!" print >> sys.stderr, "Please lodge a bug report at: https://github.com/mitmproxy/mitmproxy" finally: # Make sure that we close the server connection in any case. # The client connection is closed by the ProxyServer and does not have be handled here. self.del_server_connection() def del_server_connection(self): """ Deletes (and closes) an existing server connection. """ if self.server_conn and self.server_conn.connection: self.server_conn.finish() self.server_conn.close() self.log("serverdisconnect", "debug", ["%s:%s" % (self.server_conn.address.host, self.server_conn.address.port)]) self.channel.tell("serverdisconnect", self) self.server_conn = None def set_server_address(self, address): """ Sets a new server address with the given priority. Does not re-establish either connection or SSL handshake. """ address = tcp.Address.wrap(address) # Don't reconnect to the same destination. if self.server_conn and self.server_conn.address == address: return if self.server_conn: self.del_server_connection() self.log("Set new server address: %s:%s" % (address.host, address.port), "debug") self.server_conn = ServerConnection(address) def establish_server_connection(self, ask=True): """ Establishes a new server connection. If there is already an existing server connection, the function returns immediately. By default, this function ".ask"s the proxy master. This is deadly if this function is already called from the master (e.g. via change_server), because this navigates us in a simple deadlock (the master is single-threaded). In these scenarios, ask=False can be passed to suppress the call to the master. """ if self.server_conn.connection: return self.log("serverconnect", "debug", ["%s:%s" % self.server_conn.address()[:2]]) if ask: self.channel.ask("serverconnect", self) try: self.server_conn.connect() except tcp.NetLibError, v: raise ProxyError(502, v) def establish_ssl(self, client=False, server=False, sni=None): """ Establishes SSL on the existing connection(s) to the server or the client, as specified by the parameters. """ # Logging if client or server: subs = [] if client: subs.append("with client") if server: subs.append("with server (sni: %s)" % sni) self.log("Establish SSL", "debug", subs) if server: if not self.server_conn or not self.server_conn.connection: raise ProxyError(502, "No server connection.") if self.server_conn.ssl_established: raise ProxyError(502, "SSL to Server already established.") try: self.server_conn.establish_ssl( self.config.clientcerts, sni, method=self.config.openssl_server_method, options=self.config.openssl_server_options ) except tcp.NetLibError as v: e = ProxyError(502, repr(v)) # Workaround for https://github.com/mitmproxy/mitmproxy/issues/427 # The upstream server may reject connections without SNI, which means we need to # establish SSL with the client first, hope for a SNI (which triggers a reconnect which replaces the # ServerConnection object) and see whether that worked. if client and "handshake failure" in e.message: self.server_conn.may_require_sni = e else: raise e if client: if self.client_conn.ssl_established: raise ProxyError(502, "SSL to Client already established.") cert, key, chain_file = self.find_cert() try: self.client_conn.convert_to_ssl( cert, key, method=self.config.openssl_client_method, options=self.config.openssl_client_options, handle_sni=self.handle_sni, cipher_list=self.config.ciphers, dhparams=self.config.certstore.dhparams, chain_file=chain_file ) except tcp.NetLibError as v: raise ProxyError(400, repr(v)) # Workaround for #427 part 2 if server and hasattr(self.server_conn, "may_require_sni"): raise self.server_conn.may_require_sni def server_reconnect(self, new_sni=False): address = self.server_conn.address had_ssl = self.server_conn.ssl_established state = self.server_conn.state sni = new_sni or self.server_conn.sni self.log("(server reconnect follows)", "debug") self.del_server_connection() self.set_server_address(address) self.establish_server_connection() for s in state: protocol_handler(s[0])(self).handle_server_reconnect(s[1]) self.server_conn.state = state # Receiving new_sni where had_ssl is False is a weird case that happens when the workaround for # https://github.com/mitmproxy/mitmproxy/issues/427 is active. In this case, we want to establish SSL as well. if had_ssl or new_sni: self.establish_ssl(server=True, sni=sni) def finish(self): self.client_conn.finish() def log(self, msg, level, subs=()): msg = [ "%s:%s: %s" % (self.client_conn.address.host, self.client_conn.address.port, msg) ] for i in subs: msg.append(" -> " + i) msg = "\n".join(msg) self.channel.tell("log", Log(msg, level)) def find_cert(self): if self.config.certforward and self.server_conn.ssl_established: return self.server_conn.cert, self.config.certstore.gen_pkey(self.server_conn.cert), None else: host = self.server_conn.address.host sans = [] if self.server_conn.ssl_established and (not self.config.no_upstream_cert): upstream_cert = self.server_conn.cert if upstream_cert.cn: host = upstream_cert.cn.decode("utf8").encode("idna") sans = upstream_cert.altnames elif self.server_conn.sni: sans = [self.server_conn.sni] ret = self.config.certstore.get_cert(host, sans) if not ret: raise ProxyError(502, "Unable to generate dummy cert.") return ret def handle_sni(self, connection): """ This callback gets called during the SSL handshake with the client. The client has just sent the Sever Name Indication (SNI). We now connect upstream to figure out which certificate needs to be served. """ try: sn = connection.get_servername() if not sn: return sni = sn.decode("utf8").encode("idna") if sni != self.server_conn.sni: self.log("SNI received: %s" % sni, "debug") # We should only re-establish upstream SSL if one of the following conditions is true: # - We established SSL with the server previously # - We initially wanted to establish SSL with the server, # but the server refused to negotiate without SNI. if self.server_conn.ssl_established or hasattr(self.server_conn, "may_require_sni"): self.server_reconnect(sni) # reconnect to upstream server with SNI # Now, change client context to reflect changed certificate: cert, key, chain_file = self.find_cert() new_context = self.client_conn._create_ssl_context( cert, key, method=self.config.openssl_client_method, options=self.config.openssl_client_options, cipher_list=self.config.ciphers, dhparams=self.config.certstore.dhparams, chain_file=chain_file ) connection.set_context(new_context) # An unhandled exception in this method will core dump PyOpenSSL, so # make dang sure it doesn't happen. except: # pragma: no cover import traceback self.log("Error in handle_sni:\r\n" + traceback.format_exc(), "error")