space data link secure protocol simulator bruno saba dct/tv/in 15/04/2010

Space Data Link Secure Protocol Simulator

Bruno Saba

DCT/TV/IN

15/04/2010

Space Data Link Secure Protocol Simulator CNES DCT/TV/IN B. Saba 14/04/2010 2

Rationale

■A Secure Space Data Link Protocol has been developped for CNES by Thales Alenia Space (CNES R&D funds)

■The same contract included the developement of this simulator, in order to validate all the concepts of the Secure Protocol


Main Features

■ Simulation of a complete end to end Secure TM/TC link between a ground center and a spacecraft

Ground Data Link Layer Node for TC Forward link (GND-FWD)

Forward link ( TC : Ground Spacecraft) Spacecraft Data Link Layer Node for TC

Forward link (SC-FWD) Spacecraft Data Link Layer Node for TM

Return link (SC-RTN) Return link (TM : Spacecraft Ground) Ground Data Link Layer Node for TM

Return link (GND-RTN)

Simulator management

GND-FWD SC-FWD

GND-RTN SC-RTN

Forward link

Return link


Block Diagram

TC or AOS Fwd SDLP

Secured TM/TC Protocol

Simulation Scenarii &

Configuration

Simulation Results& Logs

Ground Simulation Spacecraft Simulation

TM / AOS Rtn link

Emulation of Data link protocol sublayer

TC or AOS Fwd SDLP

TM or AOS Rtn SDLP

TM or AOS Rtn SDLP

Emulation of Data link protocol sublayer

TC / AOS Fwd link

Security TM dataSecurity TM data CLCWCLCW

Secured TM/TC ProtocolSecured TM/TC Protocol

Secured TM/TC Protocol


Blocks description

■ Ground Data Link Layer for TC Forward Link (GND-FWD) Supports ground part of CCSDS TC data link protocol sublayer Supports ground part of Secure Protocol Generates TC frames (from a scenario file) and gives them to the Forward Link

for transmission

■ Forward Link “Sender” Transmits the TC frames to the “transmission channel” Transmission channel : UDP/IP socket (localhost)

GND-FWD SC-FWD

GND-RTN SC-RTN

Forward link

Return link

GND-FWD


Blocks description (cont’d)■ Forward Link “Receiver”

Receives the TC frames from the UDP/IP socket “transmission channel” (localhost)

Gives the received TC frames to the Spacecraft Data Link Layer Node for Forward link

■ Spacecraft Data Link Layer Node for TC Forward Link (SC-FWD) Supports on-board part of CCSDS TC data link protocol sublayer Supports on-board part of Secure Protocol Provides CLCW to the Spacecraft Data Link Layer Node for TM Return link

GND-FWD SC-FWD

GND-RTN SC-RTN

Forward link

Return link

SC-FWD


Blocks description (cont’d)

■ Interface between Spacecraft Nodes Supports routing of CLCW and Security TM data from SC-FWD to SC-RTN nodes

■ Spacecraft Data Link Layer Node for TM Return Link (SC-RTN) Supports on-board part of CCSDS TM data link protocol sublayer Supports on-board part of Secure Protocol Generates TM Frames and inserts CLCW at the right place in TM data stream

■ Return Link “Sender” Transmits the TM frames + CLCW to the “transmission channel” Transmission channel : UDP/IP socket (localhost)

GND-FWD SC-FWD

GND-RTN SC-RTN

Forward link

Return linkSC-RTN



■ Return Link “Receiver” Receives TM frames + CLCW from the UDP/IP socket “transmission channel” (localhost) Gives the received data to the Ground Data Link Layer Node for Return Link

■ Ground Data Link Layer Node for TM Return link (GND-RTN) Supports ground part of CCSDS TM data link protocol sublayer Supports ground part of Secure TM protocol

■ Interface between ground nodes Supports routing of CLCW and Security TM Data from GND-RTN to GND-FWD nodes

GND-FWD SC-FWD

GND-RTN SC-RTN

Forward link

Return linkGND-RTN



■ Simulator Management Provides complete control of the simulator by the user, both on-line or off-line

On-line : with operator present Off-line : no operator present, use of ASCII files

Reads scenario from file TC and TM channels configurations (Unprotected, Authenticated, Authenticated and Encrypted) Keys used, …

Writes log results to file Frames exchanges, errors, etc…

Provides synchronisation between processes


Software architecture

globalSim

scRtn

gndFwd

configuration

simSec

testCrytoDllNew.dll

gndRtn

scFwd

security

CryptoHMAC.dll

udp link

udp link

definesutil


Next Step

■ Split the simulator in two completely independent programs

(1) Ground node

Elaborates TC frames (from scenario, or from a file received from Internet) Computes TC security functions Performs the ground part of the CCSDS TC link protocol (COP-1 management, …) Sends the Secure TC Frames to the Spacecraft Node via UDP/IP socket

Receives TM frames from UDP/IP socket Computes TM security functions Retrieves CLCW and pass it on to the COP-1 management process Compares the plaintext TM frame with the expected data (from scenario, or from a file received

from Internet)

Performs control and monitoring functions, and synchronisation with the other node (exchange of data files via Internet)


Next Step (cont’d)

(2) Spacecraft node

Receives Secure TC frames from UDP/IP socket Performs the Spacecraft part of the CCSDS TC link protocol (FARM-1 management) Computes Security functions for TC link Generates CLCW and Security TM data, and pass them on to the TM frame generation process Compares the plaintext received TC frames with the expected data (from scenario, or from a file

received from Internet)

Generates TM frames (from scenario, or from a file received from Internet) Computes security functions for TM link Performs the Spacecraft part of the CCSDS TM link (inserts CLCW, …) Sends the TM frames to the Ground node via UDP/IP socket

Performs control and monitoring functions, and synchronisation with the other node (exchange of data files via Internet)


Conclusion

■From the existing simulator, CNES can easily reuse the basic blocks to develop a new simulator for interoperability testing

■This new simulator will be composed of two independant parts Ground Node simulator Spacecraft Node simulator

■The interface between Ground Node and Spacecraft Node being based on UDP/IP, the frames could be sent easily via Internet to realize interoperability tests between two different Space Agencies

space data link secure protocol simulator bruno saba dct/tv/in 15/04/2010

Documents