Community Day 2019 Sponsors

How to implement data encryption at rest in compliance with enterprise requirements

Steffen Mazanek, Louay Mresheh | 09/09/2019

About the speakers

Steffen Mazanek (AWS usergroup Dresden)

Louay Mresheh

• AWS architecture and security

• T-Systems International GmbH / Public Cloud unit

2

Connect on LinkedIn

Agenda

• AWS security in general

• Motivation for data protection, encryption requirements and KMS overview

• KMS hands-on / demos

• Managed security and compliance

3

4

Security “in” the cloud is not easy

Lax or misconfiguration as #1 threat

https://aws.amazon.com/compliance/shared-responsibility-model/

.

SecuritySecurity

Security as a central pillar for good architecture in the “AWS Well-Architected Framework”

Source: https://wa.aws.amazon.com/wat.design_principles.wa-dp.en.html

Operational Excellence

Reliability

Performance Efficiency

Cost Optimization

5

✓ Implement a strong identity foundation

✓ Enable traceability

✓ Apply security at all layers

✓ Automate security best practices

✓ Protect data in transit and at rest

✓ Keep people away from data

✓ Prepare for security events

.

Security: relevant AWS services (extract)

6

Identity and Access Management

Detective Controls

Config

Infrastructure Protection

Data Protection

Incident Response

IAM OrganizationsMFA token

Temporary security credential

CloudWatch CloudTrail

VPC WAFShield Inspector

Macie KMS

IAM

GuardDuty

Lambda

Security Hub

Secrets Manager

Config CloudWatch

Trusted Advisor

Cognito

CloudHSM Certificate Manager

Agenda

• AWS security in general

• Motivation for data protection, encryption requirements and KMS overview

• KMS hands-on / demos

• Managed security and compliance

7

Don‘t be the company from the news

8

• Check your snapshots:

• filter for public in console

• Better: activate a control, AWS managed config rule is available(https://docs.aws.amazon.com/config/latest/developerguide/ebs-snapshot-public-restorable-check.html)

• Use encryption, only unencrypted snapshots can be made publicly available(https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-modifying-snapshot-permissions.html)

https://techcrunch.com/2019/08/09/aws-ebs-cloud-backups-leak/

Why data encryption?

• Compliance, enterprise regulation / policies

• Security best practice

• Protection from hypervisor mistakes, e.g.• your disk is accidentally shared with another client

• mistake in disk decommissioning process

• Data confidentiality and integrity

• Control/minimize access to data (keep people away from data)

• Destroy large amounts of data by deleting the key

9

Concepts/terminology

• Data encryption in transit → IPSec/VPN, TLS (AWS Certificate Manager)

• Data encryption at rest → focus of this presentation

• Client-side → encrypt before submitting data to AWS, AWS encryption SDK in different programming languages, service clients etc.

• Server-side → AWS encrypts the data after it is received by the service

10

Enterprise data encryption requirements example• For the data protection class PUBLIC encryption is not required.

• For the data protection class INTERNAL encryption with AWS-managed key must be used.

• For the data protection class CONFIDENTIAL encryption with customer-managed key must be used.

• Keys need to be rotated on regular basis.

• Management and use of keys according to least privileges principal.

• A dedicated role group for key admins must be used.

• Multi-factor authentication must be implemented for critical KMS API calls.

• KMS key activities must be logged.

• The deletion of keys must be alarmed.

• If encryption context is used, no sensitive data must be used for encryption context.

→ Example implementation/architecture in demo part

11

CIS recommendations regarding data protection

https://d1.awsstatic.com/whitepapers/compliance/CIS_Amazon_Web_Services_Three-tier_Web_Architecture_Benchmark.pdf

Work with multiple CMKs → More fine-grained control

12…

KMS overview and concepts• securely store the keys you use to encrypt your data in

the cloud and centrally manage these keys

• Envelope encryption / two-tiered key hierarchy

• 4KB limit, better performance

• Unique data key encrypts customer data

• Customer master keys encrypt data keys

• Centralized access and better auditability

• Limits blast radius (compromised data key)

13

KMS CLI session

aws kms generate-data-key --key-id <keyarn> --key-spec AES_256 --output text --query CiphertextBlob | base64 --decode > encrEnvelopeKey

envelopeKey=$(aws kms decrypt --ciphertext-blob fileb://encrEnvelopeKey --output text --query Plaintext)openssl enc -in confidential-data.txt -out encrypted-data.txt -e -aes256 -k $envelopeKey

Keep your encrypted data key at a safe place!!Later:

envelopeKey=$(aws kms decrypt --ciphertext-blob fileb://encrEnvelopeKey --output text --query Plaintext)openssl enc -in encrypted-data.txt -out confidential-data.txt -d -aes256 -k $envelopeKey

https://docs.aws.amazon.com/cli/latest/reference/kms/

KMS overview and concepts• Regional service

• Integrated with most AWS services, but in different ways

• EBS -> encrypted data key stored with every volume, plaintext key in hypervisor memory until disk getsdetached

• S3 -> encrypted data key stored with every object

• AWS managed CMK, one per service called aws/ebs, aws/rds etc.

• Customer-managed CMK for more granularity and control

• Cause costs (per month, per key, per version)

• you can bring your own crypto material in order to keep your own copy of the key

• Key aliases, key rotation

15

KMS overview and concepts• Keys can be shared across accounts

• Critical KMS events can be monitered and automatically remediated in case of anyviolation detected, automation is key!

• AWS-managed config rules can be used to check encryption settings for DBs, disksand buckets

• KMS comes with a waiting period on key deletion (if you did not bring your own key)

• KMS is relying on shared HSMs (FIPS 140-2 Level 2)

• https://d1.awsstatic.com/whitepapers/KMS-Cryptographic-Details.pdf

16

https://aws.amazon.com/blogs/security/are-kms-custom-key-stores-right-for-you/

• Dedicated HSM in VPC →CloudHSM service (FIPS 140-2 L 3)

• Custom key store provides moreflexibility with CloudHSM butis more complex to manage

Managing access to keys from two sides• Key policy

• Define who can manage the key (you can even lock out root)

• Define who can use the key

• You can lock yourself out → AWS support case

• You can delegate to IAM

• Service roles might need access (e.g. Cloud9 needs access to EBS key)

• IAM

18

{

"Sid": "Allow access for Key Administrators",

"Effect": "Allow",

"Principal": {

"AWS": "arn:aws:iam::<accountid>:role/Project_Key_Admin“ → give access to key admin role OR

"AWS": "arn:aws:iam::<accounted>:root“ → access is controlled via IAM

},

"Action": [

"kms:Create*",

"kms:Describe*",

"kms:List*",

"kms:Enable*",

"kms:Disable*",

"kms:Get*",

"kms:Put*",

"kms:Update*",

"kms:Revoke*",

"kms:Delete*",

"kms:ScheduleKeyDeletion",

"kms:CancelKeyDeletion"

],

"Resource": "*"

},

https://docs.aws.amazon.com/de_de/kms/latest/developer

guide/key-policies.html

Agenda

• AWS security in general

• Motivation for data protection, encryption requirements and KMS overview

• KMS hands-on / demos

• Managed security and compliance

20

Demo 1

Creation of a new S3 bucket→ auto-tag with internal, disclose and encrypt

21

DPC (Data Protection Class) Encryption

confidential KMS key

internal S3-SSE

public None

Demo 2

Disabling EBS encryption by default triggers a notification and automation to enable it again

22

Demo 3

23

Key creation triggers an automated check, right policies need to be attached and key rotation being enabled

Demo 4

24

Critical KMS events such as key deletion trigger an alarm

Agenda

• AWS security in general

• Motivation for data protection, encryption requirements and KMS overview

• KMS hands-on / demos

• Managed security and compliance

25

.

Building blocks for security and compliance management

.

Managed security and compliance by T-Systems

Use of many relevant data sources

Cloud Security and Compliance as a building block for your cloud applications

Ready to use / minimal on-boarding phase

Anomaly detection

Security and compliance automation

Customer-specific compliance rules

Continuous monitoring &near-realtime alerts

Security and compliance assessment

24/7 operations and incident management

.

• 200+ AWS certifications

• 50+ Prof./Specialty Level

• Actively contributing to the AWS community

• Donating to Open Source, e.g. PacBot or VM hardening scripts

• Permanent training program

T-Systems as AWS partner

Well-architected Partner ProgramDirect Connect Partner Program

We are hiring!

Thank you! Questions?More Information about our AWS services you find here