Time is on my side -...
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Forging Wireless Timing Signals to Attack the NTP Server Time is on my side Time is on my side 1 Yuwei Zheng @HITB Haoqi Shan @HITB From: Qihoo360 Unicorn Team
Transcript of Time is on my side -...
ForgingWirelessTimingSignalstoAttacktheNTPServer
Timeisonmyside
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Yuwei Zheng @HITBHaoqi Shan @HITBFrom: Qihoo360 Unicorn Team
Maincontents
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• AbouttheNTPserver• TheNTPstratummode• Thereferenceclock• Forge radio clock signals• Forge GPS clock signals• AttackNTPserver
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AboutNTPserver
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• Aserverforcomputertosynchronizetime.
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AboutNTPserver
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• CriticalIndustriesthatuseNTPservers
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TheNTPstratummode
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• Stratum0Referenceclocks• Stratum1Primarytimeservers• Stratum2• Stratum3…• Stratum16
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AbouttheNTPserver
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• NTPserversaredeployedwithopensourceNTPv4
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Thereferenceclock
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• ReferenceClockDriversintheopensourceNTPv4Type2Deprecated: wasTrak 8820GPSReceiverType3PSTI/Traconex 1020WWV/WWVHReceiver(WWV_PST)Type4Spectracom WWVB/GPSReceivers(WWVB_SPEC)Type5TrueTimeGPS/GOES/OMEGA Receivers(TRUETIME)Type6IRIGAudioDecoder(IRIG_AUDIO)Type7RadioCHUAudioDemodulator/Decoder(CHU)…Type39hopf GPS/DCF776039forPCI-Bus(HOPF_P)Type40JJYReceivers(JJY)Type41TrueTime 560IRIG-BDecoderType42ZyferGPStarplus ReceiverType43RIPENCCinterfaceforTrimblePalisadeType44NeoClock4X- DCF77/TDFseriallineType45Spectracom TSYNCPCIType46GPSDNGclientprotocol
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Thereferenceclock
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Whydoesthestratum-1NTPserveruseradioclockandGPS?• Atomicclock,accurate,butexpensive• GPS• radioclock
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Thereferenceclock
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• ReceivercardssupportedbyNTPV4
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Thereferenceclock
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• Stratum1NTPserverproductforindustrialusing
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Thereferenceclock
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• ItsupportsDCF77,MSF,WWVB,andGPS
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Forgelongwavetimingsignals
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• DIYacircuittotransmitradioclocksignalssupportWWVB,JJY,DCF77,andMSF
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WWVBencodingandmodulation
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• Different pulse width representdifferentdatabit
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1 2 3 4t(s)
p
reduced
full
0.8s
marker 1 0 1
0.5s 0.5s0.2s
…
WWVBencodingandmodulation
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• 60Khzcarrier
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WWVBencodingandmodulation
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• ASKmodulation
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WWVBencodingandmodulation
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• Theframestructure
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JJYencodingandmodulation
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Similar to the WWVB
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1 2 3 4t(s)
p
reduced
full
0.8s
marker1 0 1
0.5s 0.5s0.2s
…
DCF77encodingandmodulation
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• SimilartoWWVB,itusesa 77.5hzcarrier
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Longwavetimingsignaltransmitter
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• Usead9850DDSmoduletogeneratethecarrier
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Longwavetimingsignaltransmitter
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• AboutAD9850DDSmodulesupportstooutput0-40Mhzwavesendsallradioclocksignalswithonecircuit
• Usearduino tocontrolad9850Ad9850seriallibraryforarduinohttps://github.com/F4GOJ/AD9850
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Longwavetimingsignaltransmitter
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• AsimpleJJYtransmittervoidsendMark(){//Sendhighfor0.2secDDS.setfreq(freq,phase);delay(200);//Sendlowfor0.8secDDS.down();delay(800);return;
}
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Longwavetimingsignaltransmitter
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• AsimpleJJYtransmittervoidsendBit1(){//Sendhighfor0.5secDDS.setfreq(freq,phase);delay(500);//Sendlowfor0.5secDDS.down();delay(500);return;
}
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Longwavetimingsignaltransmitter
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• AsimpleJJYtransmittervoidsendBitZero(){//Sendhighfor0.8secDDS.setfreq(freq,phase);delay(800);//Sendlowfor0.2secDDS.down();delay(200);return;
}
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Longwavetimingsignaltransmitter
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• GettheantennafromanJJYreceiver
L=1890uH.𝑓 = $
%& '(,for60khzcarrierC=3.6nF
Forthe77.5khzcarrier,C=2.2nF
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Longwavetimingsignaltransmitter
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• Thewholecircuitoftheuniformtransmitter
Longwavetimingsignaltransmitter
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• LongdistancetransmitterDesignapoweramplifierwithMOSFETIR540.
AttackGPSNTPreceiver
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• GPSreceiver• GPStechbriefing• GenerateGPSsignal• Haveatry• Upgradeattackalgorithm
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GPSreceiver
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• MultiplyConnection• PCI• USB• Serialport
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GPStechbriefing
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• Complicatedprinciple• Butdoesn’tmatter,it’sopen-sourced• Defcon23“GPSSpoofing- LinHuang”
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GPStechbriefing
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Subframe 1 Subframe 2 Subframe 3 Subframe 4 Subframe 5
Time information Ephemeris
GenerateGPSsignal
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Haveatry
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Panic
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Update attack algorithm
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• Find GPSTime• Replace it• Re-ParityCheck
Setup an NTP server
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• Setup an NTP server using JJY as clocksource
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server127.127.40.0mode1preferfudge 127.127.40.0flag1stratum0
Setup anNTPserver
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• ThisNTPserverwithJJYreferenceclock
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Setup an NTP server（JJY）
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AttacktheNTPserver
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• Canweinjectanytime?Thetimeoffsetmustbelessthan4hours.
• InjectatimethatisonehourslowthanrealtimeServercrashed!!!
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AttacktheNTPserver
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• Canweinjectanytime?Ifthetimeoffsetismorethan1000s,theserverwillshutdown.
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AttacktheNTPserver
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• Canweinjectanytime?theoffset>1000s,requiremanuallyadjust
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Root Dispersion
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RFC5905
Attack Demo
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Real Attack？
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Real Attack？
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Real Attack？
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Real Attack?
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Real Attack?
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• Sensitive & expensive
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References
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•“GPS Spoofing – Huang Lin”• https://www.eecis.udel.edu/~mills/ntp/html/refclock.html• http://www.sundgren.se/1-recreation/2-electronics/dcf77_simulator.htm
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Thanks
HackingFemtocell
• Any question？• Feel free to contact us!
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