mitmproxy/libmproxy/proxy/server.py
Maximilian Hils 2e6a698287 fix #308
2014-08-08 19:04:58 +02:00

286 lines
11 KiB
Python

from __future__ import absolute_import
import socket
from OpenSSL import SSL
from netlib import tcp
from .primitives import ProxyServerError, Log, ProxyError, ConnectionTypeChange, \
AddressPriority
from .connection import ClientConnection, ServerConnection
from ..protocol.handle import handle_messages, handle_error, handle_server_reconnect
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, 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: ' + 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,
self.server_version)
h.handle()
h.finish()
class ConnectionHandler:
def __init__(self, config, client_connection, client_address, server, channel,
server_version):
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, self.server_version = channel, server_version
self.close = False
self.conntype = None
self.sni = None
def handle(self):
self.log("clientconnect", "info")
self.channel.ask("clientconnect", self)
self.determine_conntype()
try:
# Can we already identify the target server and connect to it?
if self.config.get_upstream_server:
upstream_info = self.config.get_upstream_server(
self.client_conn.connection)
self.set_server_address(upstream_info[2:], AddressPriority.FROM_SETTINGS)
client_ssl, server_ssl = upstream_info[:2]
if client_ssl or server_ssl:
self.establish_server_connection()
self.establish_ssl(client=client_ssl, server=server_ssl)
while not self.close:
try:
handle_messages(self.conntype, self)
except ConnectionTypeChange:
self.log("Connection Type Changed: %s" % self.conntype, "info")
continue
except (ProxyError, tcp.NetLibError), e:
handle_error(self.conntype, self, 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"
raise
self.del_server_connection()
self.log("clientdisconnect", "info")
self.channel.tell("clientdisconnect", self)
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.log("serverdisconnect", "debug", ["%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.
"""
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), "info")
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), "debug")
self.server_conn = ServerConnection(address, priority)
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):
"""
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 a ConnTypeChanged exception will be raised.
"""
# 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"
raise ConnectionTypeChange
# 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", "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.")
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,
dhparams=self.config.certstore.dhparams,
ca_file=self.config.ca_file
)
def server_reconnect(self):
address = self.server_conn.address
had_ssl = self.server_conn.ssl_established
priority = self.server_conn.priority
state = self.server_conn.state
sni = self.sni
self.log("(server reconnect follows)", "debug")
self.del_server_connection()
self.set_server_address(address, priority)
self.establish_server_connection()
for s in state:
handle_server_reconnect(s[0], self, s[1])
self.server_conn.state = state
if had_ssl:
self.sni = sni
self.establish_ssl(server=True)
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)
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.sni:
sans = [self.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 sn and sn != self.sni:
self.sni = sn.decode("utf8").encode("idna")
self.log("SNI received: %s" % self.sni, "debug")
self.server_reconnect() # reconnect to upstream server with SNI
# Now, change client context to reflect changed certificate:
cert, key = self.find_cert()
new_context = self.client_conn._create_ssl_context(
cert, key,
method=SSL.TLSv1_METHOD,
cipher_list=self.config.ciphers,
dhparams=self.config.certstore.dhparams,
ca_file=self.config.ca_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 Exception: # pragma: no cover
import traceback
self.log("Error in handle_sni:\r\n" + traceback.format_exc(), "error")