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A Live Google+ On-Air Hangout

April 29th, 2014

Security Strategies for IoT Systems from Devices to the Cloud

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The Internet of Things Spans Markets

Smart ParkingMonitoring of parking spaces availability in the city.Structural healthMonitoring of vibrations and material conditionsin buildings, bridges and historical monuments.Noise Urban MapsSound monitoring in bar areas and centric zonesin real time.Traffic CongestionMonitoring of vehicles and pedestrian levels tooptimize driving and walking routes.Smart LightingIntelligent and weather adaptive lighting in street lights.Waste managementDetection of rubbish levels in containers to optimize thetrash collection routes.Intelligent Transportation SystemsSmart Roads and Intelligent Highways withwarning messages and diversions according to climate conditions and unexpected events like accidents or traffic jams.

Forest Fire DetectionMonitoring of combustion gases and preemptivefire conditions to define alert zones.Air PollutionControl of CO2 emissions of factories, pollutionemitted by cars and toxic gases generated in farms.Landslide and Avalanche PreventionMonitoring of soil moisture, vibrations and earthdensity to detect dangerous patterns in landconditions.Earthquake Early DetectionDistributed control in specific places of tremors

Smart Cities Smart Environment

Smart Energy

Smart GridEnergy consumption monitoring and management.

M2M ApplicationsMachine auto-diagnosis and assets control.Indoor Air Quality Toxic gas and oxygen levels gas levels in chemical plants.

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SERVICES

LAN

WAN

CLOUD

PAN

Open fridge –

remind me to track

food eaten

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Secure Data, Applications and Services Secure data storage and transmission

— Encryption algorithmic— Cryptography— Network security with both IP Security (IPsec/IKE) and SSL

Enhanced security options through ARM TrustZone®— Secure boot— Secure data storage

– secure data storage— Application download/updating — Secure event logging

Secure Lifecycle through US Computer Emergency Readiness Team (CERT) monitoring and patch support

Web service permissions, authorization and validation

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Security Needs Vary by Application

Acute Care

Proactive HealthMonitorin

g

Fitness

Healthy Lifestyle

Clinic

Hospital

ICU

Home CareChronic Disease

Management

Doctor’s Office

Community Clinic

Residential Care

Assisted Living

Skilled Nursing Facility

Diagnostics and Therapy Devices and Procedures moving away from Traditional Hospital

More Pervasive and AccessibleMore Secure, Reliable and Certified

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Security vs. Reliability

Negative vs. Positive Goal

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Threats Faced by IoT Devices Boot-time Threats

— Trust— Authentication

Run-time Threats— User space— Networking

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Root of Trust

Establishing SW / HW Trust

1. Hardware to BootROM2. BootROM to Operating System3. Operating System to Application

DeviceHardwar

e to Boot

Boot to OS

OS to Applicatio

n

Execution

Prevent untrusted OS

from launching

Prevent untrusted

Application from

executing

Prevent attacks

Authorized Access

Prevent untrusted

boot

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Boot-Time Authentication

Binary OS image authentication— Did it originate from OEM?— Has it been modified?

Memory

Nucleus Image

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Boot-Time Authentication

Private Key

Public Key

SignatureSignature Generation

Signature Verification

Nucleus RTOS

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Boot-Time Authentication Binary OS image authentication

— Did it originate from OEM?— Has it been modified? Memory

Nucleus RTOS

Signature

Match

Load Load

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First Stage Boot

LoaderSignature

Crypto Key

Establishing Root of Trust

Second Stage Boot

Loader

Signature

Crypto Key

Operating System(s)

Signature

Crypto Key

ARM TrustZone can be used for:• Crypto Key Storage• Signature Generation and

Comparison• Signature Storage• Loading OS and Apps

App 1

App 2

App NBefore loading any software, ask:• Did it come from the OEM?• Has it been tampered with?

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Boot-Time Protection

Freescale i.MX example High Assurance Boot (HAB)

— Services to ROM to authenticate software that executes immediately after ROM (typically Boot code)

— Uses Digital Signatures Used to authenticate boot code in external memory image prior to

execution Boot modes controlled by fuse setting

— NAND, SD/MMC card, EEPROM, USB HAB library contains functions to authenticate

— Authentication based on public keys using RSA algorithm– Signed off line using private keys– Image verified using public keys

— Encryption AES-128

Enable Features offered by silicon vendors to provide layered security

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BootROM to Operating System and App

Signature Generation

• Hash using SHA-1• RSA (Rivst-Shamir-Adelman) used for signature generation

with manufacturer private key• Signature and product software downloaded into external

flash memory

SHA-1 ZQ*&@Q310

RSA – private key

signature

Signature Verification

SHA-1ZQ*&@Q31

0

RSA – Public Key

signature

ZQ*&@Q310

Product Software

Compare

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User Space Threats Memory Protected

Modules Prevents sub-

systems from bringing down the system

No virtual addressing

Multiple Types Application,

Libraries, Hybrids

Memory Protection for Text Data Stack Kernel Isolation

Memory Protected

MemoryProtecte

d

MemoryProtecte

d

MemoryProtecte

d

File Systems

Peripheral Bus Drives

GUI

Power-aware Kernel

StorageLCDEthernet/Wireless

Devices

MemoryProtecte

dApplication 1Task 1Task 2…Task n

Library 1Function 1Function 2…Function n

Hybrid 1Task 1Function 1…Task nFunction n

Application 2Task 1Task 2…Task n

Networking

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Networking Threats Device Network testing

— Tests Devices with millions of attack packets to flood and stress device

— Monitor failures in protocol stack and process control functions

— Determine the functional health of the device during attack

Types of Tests— Storms

– Denial of Service tests that send packages at high rates

— Fuzzers/grammars– Invalid packets that do not conform

to protocols specifications– Fragmented packets– Overlapping packets or most but

not all of packets— Known vulnerabilities

– Packets that exploit particular vulnerabilities

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Nucleus RTOS for IoT

Hypervisor Trusted Execution Environment

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Security via ARM TrustZone

ARM TrustZone® can be thought of as a hardware-based solution that can be used to define a subset of the SoC for access by software.

Software that is designated as Secure World software has access to ALL of the SoC, while software that is designated as Normal World can access only those HW elements that are defined as “Non-Secure”.

Security can be further enhanced via– Trusted boot– Software security through separation

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ARM TrustZone WorldsSoftware that runs in the Normal World is assumed to be flawed from a safety and security perspective. This software is expected to contain bugs, exploits, hacks, faults, or irregularities that could expose sensitive information or functions.Secure World applications have complete access to the hardware and resources that are associated with both worlds.

TrustZone does nothing to improve the safety or security of the Trusted software itself which must be explicitly tested and independently validated.

1 2 3

4 5 6

7 8 9

* 0 #

Secure Element(SecurCore)

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Secure World Apps run on each core

Secure World Apps run on dedicated core

ARM TrustZone Configurations

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ARM TrustZone deficienciesTrustZone includes features that may be helpful to Multi-Core and Multi-OS support, but it alone fails to provide some fundamental capabilities typically required by an embedded system:

— No separation of Normal World resources from Secure World

— No Separation of multiple, non-Secure Domains

— Limited Device Register Data Save/Restore Function

A full safe and secure solution needs a combination of hardware and software elements using

virtualization!

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A Solution Approach: Virtualization Embedded hypervisors

— High performance, e.g. runtime and boot time

— Strong isolation— Highly robust

Hypervisor Security— Strong isolation and containment of

guests— Secure critical information and software

Widespread use of open source software— Embedded Linux gaining widespread

adoption— System robustness allowed by

separation— IP protection provided through system

partitioning

RTOSSW Stack 1 SW Stack 2

CPU Core

Mem

ory

Perip

hera

ls

Hypervisor

CPU Core

CPU Core CPU Core

RTOSRTOS

Bare-Metal

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ARM TrustZone Environment

ARM TrustZone supported features

CPU

MemoryDevices

CPU CPU CPU

Hypervisor

Mem Dev

App

RTOS

DRM

vCPU

Device A Device B Memory Memory

Normal World Secure World

Encryption

Secure Boot

Key Mgmt

Mem Dev

App

Linux

vCPU

CPU

MemoryDevices

CPU CPU CPU

Hypervisor

Mem Dev

App

RTOS

DRM

vCPU

Device A Device B Memory Memory

Encryption

Secure Boot

Key Mgmt

Mem Dev

App

Linux

vCPU

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Hypervisor and TrustZone combined

Apps

Guest kernel & drivers

Apps

Guest kernel & drivers

HypervisorHYP Mode

KernelMode

UserMode

Normal World

Secure Apps

Cortex A15 core(s)

TEE

Secure World

Hypervisor

Apps

Guest kernel & drivers

Apps

Guest kernel & drivers

Secure Apps

TEEKernelMode

UserMode

Normal World Secure World

Hypervisor

Secure Apps

TEE

Normal World Secure World

UserMode

KernelMode

Cortex A9 core(s)

Cortex A9 core(s)

Guest kernel & drivers

Apps Apps

Guest kernel & drivers

Combining Virtualization with ARM TrustZone hardware enabled capabilities present in Cortex A9 and A15 cores creates secure and robust application environment.

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BACKUP SLIDES

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Hypervisor

Normal World

Guest 1

Secure World

Guest 0

Normal and Secure World interaction

Linux App

Linux App Requiring

Secure World Support

Multicore ARM® SOC with TrustZone® Technology

MemoryDevices

Device A Device B Memory Memory

Scheduler

Linux Kernel

TrustZone Kernel Module

TEE Internal

API

Secure App 1

Cores

TrustZone Kernel Module

Secure App 2

Secure App 3

Dispatcher

Monitor

Shared Memory

Linux App

Linux App Requiring

Secure World Support

TEE Client API

Linux Kernel

TEE Client API

Kernel Space

User Space

Hypervisor

Space

FIQ

IRQFIQ

IRQ

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Virtualization: Secure Consolidation

CPU

MemoryDevices

CPU CPU CPU

Hypervisor

Mem vDev

Apps

Linux

vCPU vCPU

Mem vDev

Apps

Android

vCPU vCPU

CPU

MemoryDevices

CPU CPU CPU

Hypervisor

Mem vDev

Apps

Linux

vCPU vCPU

Mem vDev

Apps

Linux

vCPU vCPU

CPU

MemoryDevices

CPU CPU CPU

Hypervisor

Mem vDev

Apps

Linux

vCPU vCPU

Mem vDev

Apps

RTOS/BM

vCPU vCPU

Reliably run multiple of the same or different guests

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List of attacks

29

1 Account lockout attack

2 Asymmetric resource consumption (amplification)

3 Binary planting

4 Blind SQL Injection

5 Blind XPath Injection

6 Brute force attack

7 Buffer overflow attack

8 Cache Poisoning

9 Cash Overflow

10 Code Injection

11 Command Injection

12 Comment Injection Attack

13 Content Security Policy

14 Content Spoofing

15 CORS OriginHeaderScrutiny

16 CORS RequestPreflighScrutiny

17 Cross Frame Scripting

18 Cross Site History Manipulation (XSHM)

19 Cross Site Tracing

20 Cross-Site Request Forgery (CSRF)

21 Cross-site Scripting (XSS)

22 Cross-User Defacement

23 Cryptanalysis

24 CSRF

25 Custom Special Character Injection

26 Denial of Service

27 Direct Dynamic Code Evaluation ('Eval Injection')

28 Direct Static Code Injection

29 Double Encoding

30 Execution After Redirect (EAR)

31 Forced browsing

32 Format string attack

33 Full Path Disclosure

34 HTTP Request Smuggling

35 HTTP Response Splitting

36 Inyección SQL

37 LDAP injection

38 Man-in-the-browser attack

39 Man-in-the-middle attack

40 Mobile code: invoking untrusted mobile code

41 Mobile code: non-final public field

42 Mobile code: object hijack

43 One-Click Attack

44 Overflow Binary Resource File

45 Page Hijacking

46 Parameter Delimiter

47 Path Manipulation

48 Path Traversal

49 Reflected DOM Injection

50 Regular expression Denial of Service - ReDoS

51 Relative Path Traversal

52 Repudiation Attack

53 Resource Injection

54 Server-Side Includes (SSI) Injection

55 Session fixation

56 Session hijacking attack

57 Session Prediction

58 Setting Manipulation

59 Special Element Injection

60 Spyware

61 SQL Injection

62 Traffic flood

63 Trojan Horse

64 Unicode Encoding

65 Web Parameter Tampering

66 Windows ::DATA alternate data stream

67 XPATH Injection

68 XPATH Injection Java

69 XSRF

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More on AttacksCategories of Attacks    

1 7Abuse of Functionality  2 3Data Structure Attacks  3 4Embedded Malicious Cod

e 

4 9Exploitation of Authentication

 5 26 Injectio

n 

6 1Path Traversal Attack  7 4Probabilistic Techniques  8 3Protocol Manipulation  9 3Resource Depleti

on 

10 10Resource Manipulation  11 Sniffing Attacks  12 4Spoofin

g 

   total 74        

Types of Attacks  1Access Attacks  2Modification Attacks3Repudiation Attacks4Denial of Service Attacks

5Information Theft  

       

Embedded Device Attack Vectors      Loading valid software on unauthorized device  Hacking the boot process to load unauthorized OS + App  Hacking the device by loading unautharised App  Taking over the device to access data at rest  Intercepting communications to access data in transit  Uploading malware to prevent device from operating  Subjecting device to denial of service attacks to affect its operationPreventing user, device or service authentication    

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Security Framework for End Device 1. Assured data-in-transit protection

2. Assured data-at-rest protection

3. Authentication: 1. User to device

2. User to service

3. Device to service

4. Secure boot

5. Platform integrity and application sandboxing

6. Application whitelisting

7. Malicious code detection and prevention

8. Security policy enforcement

9. External Interface protection

10. Device update policy

11. Event collection for analysis

12. Incident response

CESG = UK Government's National Technical AuthorityGuidance document

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Hardware Traits of Secure Platform1. Processor Security Controls Limit Access and can not be Bypassed

2. Direct Memory Access (DMA) is Limited and Controlled

3. DMA from External Devices is Additionally Protected

4. Central Processor Access From Other Processing Elements is Minimized and Controlled

5. Tasks Consuming Platform Resources can be Identified and Controlled

6. Debug Functionality Does Not Compromise Security

7. I/O Control

8. Secure Device Identity

9. Secure Credential Storage

10. Measured/Verified Boot

11. Secure Update/Recovery

12. Control Flow Integrity

13. Security Primitives

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Communicating with the cloud Happens via web services. Multiple protocols in use including HTTP(s), Socket

Based, MQTT. HTTP based Web Services:

— Representational State Transfer (REST)— Simple Object Access Protocol (SOAP)— Remote Procedure Call (RPC)

Recommendation: use REST style services— Easy to consume— Easier to implement

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Authentication versus Authorization So you get a request from a device with some data

in the cloud… Need to know 3 things:

— Identification: Who is sending the data?— Authentication: Are they actually who they say they are? — Authorization: What are they allowed to do?

Identification and authentication go hand in hand. Authentication is typically necessary, authorization

is optional.

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Authentication Mechanisms Step 1: Decide on what kind of authentication you

will need. This depends on application, and data being stored

— User based (example: OAuth login with Facebook)— Device based (API Keys)

Benefits of OAuth:— Better UX: Lesser accounts that the user has to create/

passwords to remember.— Reduced complexity: someone else handles

authentication.— Reduced risk: Do not have to store usernames and

passwords in your datastores. API Keys:

— API keys are created in the cloud and stored on the device.

— API keys are sent with each request to authenticate device.

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Authentication with API Keys

ClientApplication

Internet CloudWeb Service

Data

Client API Key

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Authentication with API Keys

ClientApplication

Internet CloudWeb Service

API Key in header

Transmit via HTTPS

Data

Client transmits data to the cloud

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Authentication with API Keys

ClientApplication

Internet CloudWeb Service

API Key in header

Transmit via HTTPS

Data

Client transmits data to the cloud

1. Validate API key sent in request2. If validated, store data

3. Respond with success

HTTP Response 200 OKClient response

received

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Best Practices from a cloud standpoint Keep web services stateless

— Each request from the client has all the necessary information to process the request and session state is held on the device.

— Easy to scale and cache requests/responses Decide on type of authentication up front

(User/OAuth/Key based).— Depends on the usecase

Always use HTTPS.— You can encrypt your request with private keys that are

understood by the cloud and client, but never sent over the wire.

Send API keys as an HTTP Header.— Put your API keys in the HTTP Headers. Putting these in

the URL makes them cacheable and loggable

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Rugged Software Development Rugged Software movement began in 2010 as a

response to the proliferation of weak and insecure software

Rugged core values: — Repeatable— Limited attack surface— Automated configuration— Control instrumentation built-in

Applicable in cloud and web environments, but also in IoT backend services

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Generic Backend IoT Architecture

Communication Layer

Network (wifi, 3g, 4g)

API Support

Rules and Control Engine

Visualization

Logging Monitoring

Device Mgmt

Node A Node B Node n

Alerting

Applications

Mobile

Web

Node

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Threats Faced by Cloud Services The backend services that IoT devices consume

can be spoofed DDOS against cloud services can be used to make

IoT devices inoperable Weak security in multi-tenant environments can

expose data and information General web application security challenges

(OWASP)

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Agile, DevOps and Rugged Emphasis on testing and monitoring Treat server infrastructure as code and version control it Automate tests and integrate with monitoring DevOps == CAMS (Culture, Automation, Measurement

and Sharing) Use security tools as part of build candidate validation

BuildDev Test DeploySecurity Testing

~12 mos later

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Agile, DevOps and Rugged Emphasis on testing and monitoring Treat server infrastructure as code and version control it Automate tests and integrate with monitoring DevOps == CAMS (Culture, Automation, Measurement

and Sharing) Use security tools as part of build candidate validation

BuildDevTest

Deploy

Security Testing

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Expressive tooling for Security and Rugged Testing

Scenario: Using arachni, look for cross site scripting and verify no issues are found

Given "arachni" is installed

And the following profile:

| name | value |

| url | http://localhost:80 |

When I launch an "arachni-simple_xss" attack

Then the output should contain "0 issues were detected.”

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Security Strategies for IoT: From Devices to the Cloud

Thank you for attending. The archived video of this hangout will be available on this event

page shortly.

For any questions email us at embedded_software@mentor.com or visit us at http://www.mentor.com/embedded .