More and more IoT vulnerabilities are found and showcased at security events. From connected thermostats to power plants! Insecurity became the favorite subject for creating catchy IoT headlines: "Connected killer toaster", "Fridges changed into spamming machines","Privacy concerns around connected home". We will explore the five challenges one has to face when building a secure IoT solution: - hardware security: how to avoid rogue firmwares and keep your security keys safe? - upgrade strategy: you can't secure what you can't update! - secure transport: no security without secure transports. - security credentials distribution: how to distribute security keys to a fleet with millions of devices? - cloud vulnerability mitigation, how to keep your fleet of devices safe from the next Heartbleed? Current enterprise infrastructure provides solutions for handling application security but are they really matching the IoT challenge? Could running a PKI client on a low power wireless sensor node be an option? Despite those difficulties, we will show how a modern IoT device management standard like Lightweight M2M with DTLS is the way for building a secur-first IoT solutions. It provides a solution for upgrading your device, distributing your security keys and comes with a full range of cryptography cipher suites, from PSK algorithm for very constrained devices to high level of security using X.509 certificates. Furthermore for adding security to your solution we will present you ready to use opensource libraries for implementing secure IoT servers and devices. The way for quickly releasing your next catchy connected product.! Ultimately we will showcase Wakaama and Leshan, the Eclipse IoT Lightweight M2M implementation maybe your next best friend in the troubled water of Internet-Of-Things security!

1. The 5 Elements of IoT
Security
Julien Vermillard - Sierra Wireless

2. Who am I?
Software Engineer Sierra Wireless
AirVantage.net cloud service
Eclipse IoT:
Leshan project lead
Wakaama and Californium committer
Twitter: @vrmvrm
Email: jvermillard@sierrawireless.com

3. Agenda
In the news
Hardware
OTA Upgrades
Secure Communication
Key Distribution
Cloud Security
Open Source IoT Infrastructure

4. In the news
“The killer toaster”
“The nightmare on connected home street”
“What’s wrong with connected devices”

5. HP Fortify 2014 IoT security report
Reviewed the most popular devices:
TVs, webcams, thermostats, power
outlets, sprinkler controllers,
hubs for controlling multiple devices,
door locks, home alarms,scales,
and garage door openers
90% collected personal data
70% used unencrypted network services
http://h20195.www2.hp.com/V2/GetDocument.aspx?docname=4AA5-4759ENW&cc=us&lc=en

6. Secure your hardware

7. Hardware security
Risks:
Rogue firmware
Invisible backdoor
Malicious certificate
Eavesdropping
Mitigation:
Secure storage
Secure boot
Drawbacks:
Vendor lock
Tivoization
Nest Example:
https://www.blackhat.com/docs/us-14/materials/us-14-Jin-Smart-Nest-Thermostat-A-Smart-Spy-In-Your-Home.pdf

8. You can’t secure
what you can’t update

9. High engineering and BoM cost!
Custom bootloader
Flash size

10. Flash & switch update
Firmware
V 1
Firmware
V 2
Bootloader

11. Reboot & Patch update
Firmware
Patch
Bootloader

12. Must be bulletproof
Upgrading is hard:
● NAND flash errors
● Unexpected power loss
● Network errors
● Unexpected incompatibilities
● Checksum, cryptographic signature
A 0.1% failure rate on a 1m fleet is 1000 bricked devices

13. Secure Communication

14. Cipher suite? Pre-shared key
TLS_PSK_WITH_AES_128_CCM_8
TLS_PSK_WITH_AES_128_CBC_SHA256
Client and server have a common secret
Symmetric cryptography
Tampering the device or the server give you
access to all the future and past
communications

15. Secure communication is not cheap
https://tools.ietf.org/html/draft-ietf-lwig-tls-minimal-01
+----------------------+-----------------+
| | DTLS |
| +--------+--------+
| | ROM | RAM |
+----------------------+--------+--------+
| State Machine | 8.15 | 1.9 |
| Cryptography | 3.3 | 1.5 |
| DTLS Record Layer | 3.7 | 0.5 |
+----------------------+--------+--------+
| TOTAL | 15.15 | 3.9 |
+----------------------+--------+--------+
Table 1: Memory Requirements in KB

16. Cipher suite? Public Key
TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Server and client don’t share private keys,
only public keys
Perfect forward secrecy: past communication
can’t be decrypted after secret compromission

17. X.509 Certificate
Chain-of-trust for validating identity!
No more credential provisioning
Used for HTTPS

18. Certificate: revocation checks
Revocation checking is still an issue in 2015:
Validity date checking: RTC? NTP?
More and more complexity on the device side:
CRL, OCSP, stapling
Hard fail? Soft fail? Certificate pinning?

19. Pre-shared key vs X.509?
PSK is lighter, can run on very small target
X.509 crypto is heavier: (EC)DH,ECDSA/RSA
PSK Infrastructure is simpler but weaker
(Hello SIM card key files)
X.509 Public Key Infrastructure is complex, but
can be outsourced

20. Key Distribution

21. Pre-shared key generation
Everything should be provisioned at factory?
Don’t move big plain text list of credentials
Don’t use stupid formulas:
password = MD5(IMEI + CARRIER_NOT_SO_SECRET)
https://www.blackhat.com/docs/us-14/materials/us-14-
Solnik-Cellular-Exploitation-On-A-Global-Scale-The-Rise-
And-Fall-Of-The-Control-Protocol.pdf

22. Secret rotation
Be sure to be ready to change them ASAP
Don’t wait the next Heartbleed for doing it
Good practice:
Changing the factory credential during the 1st
communication

23. Key management protocols?
Enterprise PKI for X.509: CMP, OCSP
For PSK or X.509: Lightweight M2M bootstrap

24. LwM2M bootstrap in a nutshell
Flash bootstrap
credentials

25. LwM2M bootstrap in a nutshell
I only have bootstrap
credentials or I can’t
reach final server

26. LwM2M bootstrap in a nutshell
POST /bs
Bootstrap Server

27. LwM2M bootstrap in a nutshell
Write DM
URL & credentials
Bootstrap Server

28. LwM2M bootstrap in a nutshell
DM ServerBootstrap Server
I have credential for
the DM server

29. LwM2M bootstrap in a nutshell
DM ServerBootstrap Server
POST /rd

30. LwM2M bootstrap in a nutshell
DM ServerBootstrap Server
Start managing the
device

31. Server Security

32. Why it’s mattering?
Risk:
Takeover of your whole device fleet
You are a juicy target
Mitigations:
More security (ex. 2 factor auth) than classical
web service
Collect only the necessary data
Isolate as much as possible web and devices

33. Now where I start?

34. Ask more time/budget?

36. Now you are part of the
70% unencrypted network services

37. Open-source to the rescue!

38. Eclipse IoT - Leshan
Lightweight M2M implementation in Java
A library for building:
bootstrap, and device management servers
Support DTLS PSK, RPK, (X.509 soon)
And also client for beefier devices or testing

39. Eclipse IoT - Leshan
Update firmware, software
Manage secrets (bootstrap)
Monitor and configure device
Can support custom object for applications
IPSO objects

40. Eclipse IoT - Wakaama
C implementation of Lightweight M2M
Focused on embedded
Bring your own IP stack
Bring your own DTLS implementation
Bootstrap supported

41. Eclipse IoT - Wakaama
You can receive packages for
firmware/software update
But you need to implement live re-flashing on
your platform
Known to be running on Linux, Arduino mega,
ARM Cortex processors

42. TinyDTLS | https://tindydtls.sf.net
MIT License, Eclipse proposal!
“Support session multiplexing in single-
threaded applications and thus targets
specifically on embedded systems.”
Examples for Linux, or Contiki OS

43. TinyDTLS
Supported ciphersuites:
TLS_PSK_WITH_AES_128_CCM_8
TLS_ECDHE_ECDSA_WITH_AES128_CCM_8

44. Demo!

45. From Toolbox

46. To Jump start

47. Thanks!
Questions?
Contact me:
@vrmvrm
jvermillard@sierrawireless.com
Blog post

48. +1 0 -1
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