1. Accelerator Network Safety at PSI
Dirk Zimoch :: Controls Section :: Paul Scherrer Institut
Accelerator Network Safety at PSI
6th Control System Cyber-Security Workshop at ICALEPCS 2017

2. Example: SLS External users at beamlines bring their own devices
misconfigured ?
malfunctioning ?
compromised ?
Need access to their home institutes, mail, web, …
Protect accelerator and beamlines from each other and from outside world
Confine problems
Where needed give controlled access

3. Network layout Beamline Network Beamline Network Beamline Network
Wireless Guest Network
Goals
Allow users their own equipment
Allow access to outside
Confine problems inside beamline
Protect networks from outside
Beamline Network
Beamline Network
Beamline Network
Accelerator Network
ssh
http
dhcp
General PSI Network
Separate firewalled networks
No access into beamline or accelerator
…except through defined channels

4. EPICS access Beamline Network Beamline Network Beamline Network
Beamline Channel Access Gateways
Connect beamlines with accelerator
Dual network interfaces
Beamline writable from accelerator
Accelerator not writable from beamline (except for selected channels)
EPICS access
Goals
Allow safe channel Access between beamlines and from office
Read-only access
… except for selected channels
Beamline Network
Beamline Network
r/o
Beamline Network
CA Gateway
CA Gateway
Accelerator Network
r/o
CA Gateway
CA Gateway
General PSI Network
Accelerator Channel Access Gateway
Read-only access from office
Uses non-standard port through firewall
r/o

5. Access Configuration Host
Remote Login
Goal
Allow controlled login from outside
Access Configuration Host
Single host with write access to user list drive
Only operators can log in
Operator tool modifies user list
Shift Calendar
Cron job checks shift calendar and clears or fills user list
network drive
user2
user1
Registered user list
Approved user list
Accelerator Network
ssh Gateway
sshd checks user against list
Firewall blocks login Except from ssh gateway
During operation Operators can control access
Begin of shutdown Any registered user can log in
End of shutdown No user can log in
General PSI Network