diff options
Diffstat (limited to 'libmproxy/proxy/server.py')
| -rw-r--r-- | libmproxy/proxy/server.py | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/libmproxy/proxy/server.py b/libmproxy/proxy/server.py new file mode 100644 index 00000000..37ec7758 --- /dev/null +++ b/libmproxy/proxy/server.py @@ -0,0 +1,287 @@ +import socket +from .. import version, protocol +from libmproxy.proxy.primitives import Log +from .primitives import ProxyServerError +from .connection import ClientConnection, ServerConnection +from .primitives import ProxyError, ConnectionTypeChange, AddressPriority +from netlib import tcp + + +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, port, host='', server_version=version.NAMEVERSION): + """ + Raises ProxyServerError if there's a startup problem. + """ + self.config = config + self.server_version = server_version + try: + tcp.TCPServer.__init__(self, (host, port)) + except socket.error, v: + raise ProxyServerError('Error starting proxy server: ' + v.strerror) + 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, self.server_version) + h.handle() + h.finish() + + +class ConnectionHandler: + def __init__(self, config, client_connection, client_address, server, channel, server_version): + self.config = config + self.client_conn = ClientConnection(client_connection, client_address, server) + self.server_conn = None + self.channel, self.server_version = channel, server_version + + self.close = False + self.conntype = None + self.sni = None + + self.mode = "regular" + if self.config.reverse_proxy: + self.mode = "reverse" + if self.config.transparent_proxy: + self.mode = "transparent" + + def handle(self): + self.log("clientconnect") + self.channel.ask("clientconnect", self) + + self.determine_conntype() + + try: + try: + # Can we already identify the target server and connect to it? + server_address = None + address_priority = None + if self.config.forward_proxy: + server_address = self.config.forward_proxy[1:] + address_priority = AddressPriority.FORCE + elif self.config.reverse_proxy: + server_address = self.config.reverse_proxy[1:] + address_priority = AddressPriority.FROM_SETTINGS + elif self.config.transparent_proxy: + server_address = self.config.transparent_proxy["resolver"].original_addr( + self.client_conn.connection) + if not server_address: + raise ProxyError(502, "Transparent mode failure: could not resolve original destination.") + address_priority = AddressPriority.FROM_CONNECTION + self.log("transparent to %s:%s" % server_address) + + if server_address: + self.set_server_address(server_address, address_priority) + self._handle_ssl() + + while not self.close: + try: + protocol.handle_messages(self.conntype, self) + except ConnectionTypeChange: + self.log("Connection Type Changed: %s" % self.conntype) + continue + + # FIXME: Do we want to persist errors? + except (ProxyError, tcp.NetLibError), e: + protocol.handle_error(self.conntype, self, e) + except Exception, e: + self.log(e.__class__) + import traceback + self.log(traceback.format_exc()) + self.log(str(e)) + + self.del_server_connection() + self.log("clientdisconnect") + self.channel.tell("clientdisconnect", self) + + def _handle_ssl(self): + """ + Helper function of .handle() + Check if we can already identify SSL connections. + If so, connect to the server and establish an SSL connection + """ + client_ssl = False + server_ssl = False + + if self.config.transparent_proxy: + client_ssl = server_ssl = (self.server_conn.address.port in self.config.transparent_proxy["sslports"]) + elif self.config.reverse_proxy: + client_ssl = server_ssl = (self.config.reverse_proxy[0] == "https") + # TODO: Make protocol generic (as with transparent proxies) + # TODO: Add SSL-terminating capatbility (SSL -> mitmproxy -> plain and vice versa) + if client_ssl or server_ssl: + self.establish_server_connection() + self.establish_ssl(client=client_ssl, server=server_ssl) + + def del_server_connection(self): + """ + Deletes an existing server connection. + """ + if self.server_conn and self.server_conn.connection: + self.server_conn.finish() + self.log("serverdisconnect", ["%s:%s" % (self.server_conn.address.host, self.server_conn.address.port)]) + self.channel.tell("serverdisconnect", self) + self.server_conn = None + self.sni = None + + def determine_conntype(self): + #TODO: Add ruleset to select correct protocol depending on mode/target port etc. + self.conntype = "http" + + def set_server_address(self, address, priority): + """ + Sets a new server address with the given priority. + Does not re-establish either connection or SSL handshake. + @type priority: libmproxy.proxy.primitives.AddressPriority + """ + address = tcp.Address.wrap(address) + + if self.server_conn: + if self.server_conn.priority > priority: + self.log("Attempt to change server address, " + "but priority is too low (is: %s, got: %s)" % (self.server_conn.priority, priority)) + return + if self.server_conn.address == address: + self.server_conn.priority = priority # Possibly increase priority + return + + self.del_server_connection() + + self.log("Set new server address: %s:%s" % (address.host, address.port)) + self.server_conn = ServerConnection(address, priority) + + def establish_server_connection(self): + """ + Establishes a new server connection. + If there is already an existing server connection, the function returns immediately. + """ + if self.server_conn.connection: + return + self.log("serverconnect", ["%s:%s" % self.server_conn.address()[:2]]) + self.channel.tell("serverconnect", self) + try: + self.server_conn.connect() + except tcp.NetLibError, v: + raise ProxyError(502, v) + + def establish_ssl(self, client=False, server=False): + """ + Establishes SSL on the existing connection(s) to the server or the client, + as specified by the parameters. If the target server is on the pass-through list, + the conntype attribute will be changed and the SSL connection won't be wrapped. + A protocol handler must raise a ConnTypeChanged exception if it detects that this is happening + """ + # TODO: Implement SSL pass-through handling and change conntype + passthrough = [ + # "echo.websocket.org", + # "174.129.224.73" # echo.websocket.org, transparent mode + ] + if self.server_conn.address.host in passthrough or self.sni in passthrough: + self.conntype = "tcp" + return + + # Logging + if client or server: + subs = [] + if client: + subs.append("with client") + if server: + subs.append("with server (sni: %s)" % self.sni) + self.log("Establish SSL", subs) + + if server: + if self.server_conn.ssl_established: + raise ProxyError(502, "SSL to Server already established.") + self.establish_server_connection() # make sure there is a server connection. + self.server_conn.establish_ssl(self.config.clientcerts, self.sni) + if client: + if self.client_conn.ssl_established: + raise ProxyError(502, "SSL to Client already established.") + cert, key = self.find_cert() + self.client_conn.convert_to_ssl( + cert, key, + handle_sni = self.handle_sni, + cipher_list = self.config.ciphers + ) + + def server_reconnect(self, no_ssl=False): + address = self.server_conn.address + had_ssl = self.server_conn.ssl_established + priority = self.server_conn.priority + sni = self.sni + self.log("(server reconnect follows)") + self.del_server_connection() + self.set_server_address(address, priority) + self.establish_server_connection() + if had_ssl and not no_ssl: + self.sni = sni + self.establish_ssl(server=True) + + def finish(self): + self.client_conn.finish() + + def log(self, msg, 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)) + + def find_cert(self): + host = self.server_conn.address.host + sans = [] + if not self.config.no_upstream_cert or not self.server_conn.ssl_established: + upstream_cert = self.server_conn.cert + if upstream_cert.cn: + host = upstream_cert.cn.decode("utf8").encode("idna") + sans = upstream_cert.altnames + + 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 sn and sn != self.sni: + self.sni = sn.decode("utf8").encode("idna") + self.log("SNI received: %s" % self.sni) + self.server_reconnect() # reconnect to upstream server with SNI + # Now, change client context to reflect changed certificate: + new_context = SSL.Context(SSL.TLSv1_METHOD) + cert, key = self.find_cert() + new_context.use_privatekey_file(key) + new_context.use_certificate(cert.X509) + connection.set_context(new_context) + # An unhandled exception in this method will core dump PyOpenSSL, so + # make dang sure it doesn't happen. + except Exception, e: # pragma: no cover + pass
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