feat: Support direct TLS connections.

Author: alxbl

pyrdp/layer/tcp.py

@@ -11,10 +11,15 @@
 from twisted.internet.protocol import connectionDone, Protocol
 
 from pyrdp.core import ObservedBy
+from pyrdp.core.ssl import ServerTLSContext
 from pyrdp.layer.layer import IntermediateLayer, LayerObserver
 from pyrdp.logging import LOGGER_NAMES, getSSLLogger
 from pyrdp.parser.tcp import TCPParser
 from pyrdp.pdu import PDU
+from pyrdp.mitm import MITMConfig
+
+
+TLS_RECORD = 0x16
 
 
 class TCPObserver(LayerObserver):
@@ -41,17 +46,21 @@ class TwistedTCPLayer(IntermediateLayer, Protocol):
     TCP observers are notified when a connection is made.
     """
 
-    def __init__(self):
+    def __init__(self, config: MITMConfig):
         self.log = logging.getLogger(LOGGER_NAMES.PYRDP)
         super().__init__(TCPParser())
         self.connectedEvent = asyncio.Event()
         self.logSSLRequired = False
 
+        self.new = True
+        self.config = config
+
     def logSSLParameters(self):
         """
         Log the SSL parameters of the connection in a format suitable for decryption by Wireshark.
         """
-        getSSLLogger().info(self.transport.protocol._tlsConnection.client_random(), self.transport.protocol._tlsConnection.master_key())
+        getSSLLogger().info(self.transport.protocol._tlsConnection.client_random(),
+                            self.transport.protocol._tlsConnection.master_key())
 
     def connectionMade(self):
         """
@@ -66,7 +75,7 @@ def connectionLost(self, reason=connectionDone):
         """
         self.observer.onDisconnection(reason)
 
-    def disconnect(self, abort = False):
+    def disconnect(self, abort=False):
         """
         Close the TCP connection.
         :param abort: True to force close the connection, False to end gracefully.
@@ -83,6 +92,20 @@ def dataReceived(self, data: bytes):
         Called whenever data is received.
         :param data: bytes received.
         """
+
+        # Check if the client is sending us a TLS record immediately.
+        # and start the TLS handshake early.
+        if self.new and data[0] == TLS_RECORD:
+            self.startTLS(ServerTLSContext(self.config.privateKeyFileName,
+                                           self.config.certificateFileName))
+            # Resend the ClientHello to Twisted for handshake processing.
+            # WARNING: This is using a private Twisted API which could change in the future.
+            self.transport._dataReceived(data)
+            self.new = False
+            return
+
+        self.new = False  # First packet was not a TLS record.
+
         try:
             if self.logSSLRequired:
                 self.logSSLParameters()
@@ -93,7 +116,7 @@ def dataReceived(self, data: bytes):
             raise
         except Exception as e:
             self.log.exception(e)
-            self.log.error("Exception occurred when receiving: %(data)s" , {"data": hexlify(data).decode()})
+            self.log.error("Exception occurred when receiving: %(data)s", {"data": hexlify(data).decode()})
             raise
 
     def sendBytes(self, data: bytes):
@@ -143,7 +166,7 @@ def connection_lost(self, exception=connectionDone):
         """
         self.observer.onDisconnection(exception)
 
-    def disconnect(self, abort = False):
+    def disconnect(self, abort=False):
         """
         Close the TCP connection.
         :param abort: True to force close the connection, False to end gracefully.

pyrdp/mitm/PlayerLayerSet.py

@@ -1,15 +1,16 @@
 #
 # This file is part of the PyRDP project.
-# Copyright (C) 2019 GoSecure Inc.
+# Copyright (C) 2019-2020 GoSecure Inc.
 # Licensed under the GPLv3 or later.
 #
 
 from pyrdp.layer import AsyncIOTCPLayer, LayerChainItem, PlayerLayer, TwistedTCPLayer
+from pyrdp.mitm import MITMConfig
 
 
 class TwistedPlayerLayerSet:
-    def __init__(self):
-        self.tcp = TwistedTCPLayer()
+    def __init__(self, config: MITMConfig):
+        self.tcp = TwistedTCPLayer(config)
         self.player = PlayerLayer()
         LayerChainItem.chain(self.tcp, self.player)
 
@@ -18,4 +19,4 @@ class AsyncIOPlayerLayerSet:
     def __init__(self):
         self.tcp = AsyncIOTCPLayer()
         self.player = PlayerLayer()
-        LayerChainItem.chain(self.tcp, self.player)
+        LayerChainItem.chain(self.tcp, self.player)

pyrdp/mitm/RDPMITM.py

@@ -1,6 +1,6 @@
 #
 # This file is part of the PyRDP project.
-# Copyright (C) 2019 GoSecure Inc.
+# Copyright (C) 2019-2020 GoSecure Inc.
 # Licensed under the GPLv3 or later.
 #
 
@@ -76,13 +76,13 @@ def __init__(self, mainLogger: SessionLogger, crawlerLogger: SessionLogger, conf
         self.state = state if state is not None else RDPMITMState(self.config)
         """The MITM state"""
 
-        self.client = RDPLayerSet()
+        self.client = RDPLayerSet(self.config)
         """Layers on the client side"""
 
-        self.server = RDPLayerSet()
+        self.server = RDPLayerSet(self.config)
         """Layers on the server side"""
 
-        self.player = TwistedPlayerLayerSet()
+        self.player = TwistedPlayerLayerSet(self.config)
         """Layers on the attacker side"""
 
         self.recorder = recorder if recorder is not None else MITMRecorder([], self.state)

pyrdp/mitm/layerset.py

@@ -1,10 +1,11 @@
 #
 # This file is part of the PyRDP project.
-# Copyright (C) 2019 GoSecure Inc.
+# Copyright (C) 2019-2020 GoSecure Inc.
 # Licensed under the GPLv3 or later.
 #
 
 from pyrdp.enum import SegmentationPDUType
+from pyrdp.mitm import MITMConfig
 from pyrdp.layer import FastPathLayer, LayerChainItem, MCSLayer, SecurityLayer, SegmentationLayer, SlowPathLayer, \
     TPKTLayer, TwistedTCPLayer, X224Layer
 
@@ -14,8 +15,8 @@ class RDPLayerSet:
     Class that handles initialization of regular (non-virtual channel) RDP layers.
     """
 
-    def __init__(self):
-        self.tcp = TwistedTCPLayer()
+    def __init__(self, config: MITMConfig):
+        self.tcp = TwistedTCPLayer(config)
         self.segmentation = SegmentationLayer()
         self.tpkt = TPKTLayer()
         self.x224 = X224Layer()