1. Protecting Network Equipment
Guy C Fedorkow, Juniper Networks
May 3, 2017
ESC Minneapolis

2. Agenda What is the Trusted Computing Group? What’s the threat?
The importance of locking down firmware
Networking applications for TCG Technology
References

3. Who is the Trusted Computing Group?
You know TCG for our technical specs & guidance such as:
Trusted Platform Module (TPM 2.0)
Self Encrypting Drive (SED)
Trusted Network Connect (TNC)
The Trusted Computing Group (TCG) is an international industry standards group focused on Trusted Computing since its founding in 2003.
ISO/ IEC

4. TCG = Open Standards for Trusted Computing
TCG is the only group focused on trusted computing standards
TPM specification implemented in more than a billion devices
Chips integrated into PCs, servers, printers, kiosks, industrial systems, and many embedded systems

5. The Threat Networked Equipment has become critical infrastructure
Threats include
Unauthorized devices that can gain access to networked data
Unauthorized code that can interfere with safe operation
Firmware implants that can render attacks invisible and unremovable
E.g: Ukraine Power System Attack
Coordinated attacks on controllers, embedded gear and even the call center
Some networking equipment permanently disabled
grid/
ISAC_SANS_Ukraine_DUC_18Mar2016.pdf
E.g. Dyn DNS Attack
Hundreds of thousands of IoT devices pirated to attack Dyn’s DNS servers

6. Securing Infrastructure
Today’s Scope: Embedded systems like routers, firewalls, switches, industrial controllers
It’s important to consider security at all levels
But particularly Firmware and Identity
Part One – securing firmware
Part Two – Using the TPM

7. Secure Boot Defined
Secure Boot(*) is a process that ensures that the device boots an unmodified, authorized image.
Secure Boot is achieved by providing an unbroken “chain of trust” from the first instruction executed after Reset through to the OS prompt.
BIOS checks Loader Signature before handoff
Loader checks Kernel Signatures before handoff
Start BIOS Initialize hardware
Check Loader Signature
Run Loader Locate OS Image Check Kernel Signatures
Kernel Start OS (eg Linux)
Check and run Daemons
*aka Verified Boot
Core Root of Trust

8. Firmware Attacks Why so much focus on firmware attacks?
It’s the first link in the chain of trust
If you skip a link in the chain, that invalidates the rest
Firmware Hacks are usually persistent
Firmware is not usually updated or examined
Good for stealthy attacks
Hacks can be un-removable*
The BIOS updates the BIOS
So if it doesn’t want to, it won’t 
*Without a hardware programmer

9. Securing Firmware Two Simple Steps:
Make sure that the OS cannot modify firmware
This usually needs some kind of hardware help to lock boot flash memory
Make sure that the BIOS (or uBoot or whatever) won’t update itself without checking a signature on the new image.

10. Trusted Platform Module: The Standard Hardware Root of Trust
Trusted Platform Module (TPM)
Self-contained security processor
Inexpensive & small (~1 watt, ~$1)
Connects to inexpensive processor buses
TPM Provides:
Secure storage of boot state (i.e. hashes of objects)
Secure storage of cryptographic secrets (e.g. private keys)
Cryptographic-quality Random Number Generator
Includes resistance to physical attack, i.e., reverse- engineering, to keep private keys private
Specified by Trusted Computing Group industry consortium

11. TCG Network Equipment Guidance
TCG Guidance for Securing Network Equipment
Document under development by TCG members including those involved in Networking
Juniper, Cisco, Huawei, HP and others
Intended to help equipment vendors use TCG technology to secure network infrastructure

12. Applications for TPM in Networked Gear
Cryptographic Random Number Generator
Sealing Secrets
Cryptographic Device Identification
Software Attestation / Health-Check
… And many others

13. Random Number Generator - Essential for Secure Protocols
Protocols like IPsec, SSH, SSL and TLS use cryptographic keys
Keys are often generated within the embedded device itself
Keys are like passwords: if you can guess the key, you can break the protocol
Cryptographic keys are typically generated from random numbers
Without hardware help, computer algorithms can only generate Pseudo-Random sequences, not truly random numbers.
Most TPMs contain a physical source of randomness (aka entropy) which can be used to generate reliable keys.

14. Sealing Secrets - Ensure that secrets remain secret!
The TPM can be used to protect secrets like:
VPN shared-secret keys
Disk Encryption keys
Program the TPM so it will only decrypt the secrets for use when the platform is in a specified state, e.g.
Known, unmodified OS
And/or specific platform configuration
And/or user password

15. IEEE802.1AR Device Identity - Proves Which Device is Which
Many embedded devices are ‘remote’ and difficult to protect or even identify reliably.
The TPM can be programmed with a unique cryptographic identifier based on device serial number
Based on IEEE spec 802.1AR
Public Key Cryptography allows the TPM to assert its identity
And then prove possession of a difficult-to-steal private key stored inside the TPM

16. How Would a DevID be Used?
Inventory – Ensure the devices you put in place are still there
VPN login – Use DevID for remote login, so only authorized devices are allowed on your network
Zero-Touch Configuration – Ensure that only authorized devices can call in to obtain configuration
Software licensing and feature activation – ensure that only authorized devices can run value-add features

17. Attestation and Measured Boot - Proves What Software was Launched on your Device
Secure Boot works well for deterministic early stages of boot
But multi-core processors tend to be less predictable once the OS layer starts up
The TPM can be used to record “measurements” of each executable run
The TPM can then return those measurements to a management station later, signed by a key that only the TPM can know
“Attestation” provides cryptographic assurance of which executables actually were run.

18. What Can You Do?
Lock down your firmware
Use a cryptographic Random Number Generator
Use DevID to identify embedded devices
See NetEq Synopsis for more on securing network equipment
content/uploads/NetEq-Synopsis_1_0r3.pdf
Join TCG to go deep into the topic
Contribute to the work!

19. More Info TCG: www.trustedcomputinggroup.org
NetEQ docs: systems/
TPM docs: module/
TPM/ba-p/281128
Secure-Boot-and-Measured-Boot/ba-p/281251
TPM & secure boot:
us/windows/hardware/commercialize/manufacture/desktop/secure-boot-overview

20. Thank You!
Questions?
@ESC_Conf
ESC Minneapolis

21. Contacting Trusted Computing Group
LinkedIn Trusted Computing Group:
YouTube channel:
BrightTalk webcasts (free): search “trusted computing” for library of demonstrations and presentations