def get_upstream_server(self, client_conn):
try:
# Parse Client Greeting
client_greet = socks.ClientGreeting.from_file(client_conn.rfile)
self._assert_socks5(client_greet)
if socks.METHOD.NO_AUTHENTICATION_REQUIRED not in client_greet.methods:
raise socks.SocksError(
socks.METHOD.NO_ACCEPTABLE_METHODS,
"mitmproxy only supports SOCKS without authentication")
# Send Server Greeting
server_greet = socks.ServerGreeting(
socks.VERSION.SOCKS5, socks.METHOD.NO_AUTHENTICATION_REQUIRED)
server_greet.to_file(client_conn.wfile)
client_conn.wfile.flush()
# Parse Connect Request
connect_request = socks.Message.from_file(client_conn.rfile)
self._assert_socks5(connect_request)
if connect_request.msg != socks.CMD.CONNECT:
raise socks.SocksError(
socks.REP.COMMAND_NOT_SUPPORTED,
"mitmproxy only supports SOCKS5 CONNECT.")
# We do not connect here yet, as the clientconnect event has not
# been handled yet.
connect_reply = socks.Message(
socks.VERSION.SOCKS5,
socks.REP.SUCCEEDED,
socks.ATYP.DOMAINNAME,
# dummy value, we don't have an upstream connection yet.
client_conn.address)
connect_reply.to_file(client_conn.wfile)
client_conn.wfile.flush()
ssl = bool(connect_request.addr.port in self.sslports)
return ssl, ssl, connect_request.addr.host, connect_request.addr.port
except socks.SocksError as e:
msg = socks.Message(5, e.code, socks.ATYP.DOMAINNAME, repr(e))
try:
msg.to_file(client_conn.wfile)
except:
pass
raise ProxyError(502, "SOCKS5 mode failure: %s" % str(e))
def __call__(self):
try:
# Parse Client Greeting
client_greet = socks.ClientGreeting.from_file(self.client_conn.rfile, fail_early=True)
client_greet.assert_socks5()
if socks.METHOD.NO_AUTHENTICATION_REQUIRED not in client_greet.methods:
raise socks.SocksError(
socks.METHOD.NO_ACCEPTABLE_METHODS,
"mitmproxy only supports SOCKS without authentication"
)
# Send Server Greeting
server_greet = socks.ServerGreeting(
socks.VERSION.SOCKS5,
socks.METHOD.NO_AUTHENTICATION_REQUIRED
)
server_greet.to_file(self.client_conn.wfile)
self.client_conn.wfile.flush()
# Parse Connect Request
connect_request = socks.Message.from_file(self.client_conn.rfile)
connect_request.assert_socks5()
if connect_request.msg != socks.CMD.CONNECT:
raise socks.SocksError(
socks.REP.COMMAND_NOT_SUPPORTED,
"mitmproxy only supports SOCKS5 CONNECT."
)
# We always connect lazily, but we need to pretend to the client that we connected.
connect_reply = socks.Message(
socks.VERSION.SOCKS5,
socks.REP.SUCCEEDED,
connect_request.atyp,
# dummy value, we don't have an upstream connection yet.
connect_request.addr
)
connect_reply.to_file(self.client_conn.wfile)
self.client_conn.wfile.flush()
except (socks.SocksError, TcpException) as e:
raise Socks5ProtocolException("SOCKS5 mode failure: %s" % repr(e))
# https://github.com/mitmproxy/mitmproxy/issues/839
address_bytes = (connect_request.addr.host.encode("idna"), connect_request.addr.port)
self.server_conn.address = tcp.Address(address_bytes, connect_request.addr.use_ipv6)
layer = self.ctx.next_layer(self)
try:
layer()
finally:
if self.server_conn:
self.disconnect()
def test_no_connect(self):
"""
mitmproxy doesn't support UDP or BIND SOCKS CMDs
"""
p = self.pathoc()
with p.connect():
socks.ClientGreeting(
socks.VERSION.SOCKS5,
[socks.METHOD.NO_AUTHENTICATION_REQUIRED]).to_file(p.wfile)
socks.Message(socks.VERSION.SOCKS5, socks.CMD.BIND,
socks.ATYP.DOMAINNAME,
("example.com", 8080)).to_file(p.wfile)
p.wfile.flush()
p.rfile.read(2) # read server greeting
f = p.request(
"get:/p/200"
) # the request doesn't matter, error response from handshake will be read anyway.
assert f.status_code == 502
assert b"SOCKS5 mode failure" in f.content
def test_message_unknown_atyp():
raw = tutils.treader("\x05\x02\x00\x02\x7f\x00\x00\x01\xDE\xAD\xBE\xEF")
tutils.raises(socks.SocksError, socks.Message.from_file, raw)
m = socks.Message(5, 1, 0x02, tcp.Address(("example.com", 5050)))
tutils.raises(socks.SocksError, m.to_file, StringIO())
