How To Use Aws.Com

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Crypto-Options on AWS

Bertram Dorn – Specialized Solutions Architect

Security/Compliance

Network/Databases

Amazon Web Services Germany GmbH

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Agenda

• Theory

• Options

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The Cryptographic Trinity

Key

Algorithm

Data

If you don’t own all three parts of the solution, your

data is not considered to be “hard” encrypted…

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In Region I:

AWS AZ AWS AZ

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In Region II:

AWS DC AWS DC

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Between Regions:

Region Availability Zone

Availability Zone

Availability Zone Public

Customer DX Site WAN

DX Site

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Summary

• Data in transit within an AZ might leave the building

• Data in transit between AZs will leave the building

• Data in transit between AWS Regions or between AWS and customer premises needs to be taken care of, too

• How about devices:

– Device decommisining is main task for AWS – This is fully compliant and audited

– No device does leave our DCs functional

– People leaving a DC need to pass a metal detector

Whatever you do: Encrypt Your Data in Flight

Let’s discuss data at rest

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Discussion Points

• Hard encryption might be excessive, for some purposes

• Find out where you need which kind of encryption – map your view of risk and need

• Think about the lifetime of your data (example: German expiry of use of 3DES and resulting requirement for bulk data re-encryption with stronger algorithm…)

• Sometimes encryption is only there for Compliance reasons…

Work on your data classification

Find balance between your obligation for

executive care, cost and complexity

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But:

Getting Data at rest encrypted on AWS

So so easy that you should consider a policy:

All data need to be encrypted at rest!

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AWS services and where we look into today:

Technology Partners Consulting Partners Ecosystem AWS Marketplace

Elastic Beanstalk for Java, Node.js, Python,

Ruby, PHP and .Net Containers & Deployment (PaaS) OpsWorks CloudFormation

Management &

Administration

IAM CloudTrail Cloud HSM CloudWatch Management Console APIs and SDKs Command Line Interface

Direct Connect Route 53

Networking VPC

Analytics

Data Pipeline Redshift

EMR Kinesis CloudFront SNS SQS SES SWF AppStream CloudSearch

Application Services

WorkSpaces

Regions Availability Zones Content Delivery POPs

Storage Gateway

S3 EBS Glacier Import/Export DynamoDB ElastiCache

Storage

Compute Databases

RDS

MySQL, PostgreSQL Oracle, SQL Server Elastic Load Balancer

EC2 Auto Scaling

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AWS Key Management Service I

• Designed for Scalability and Throughput

• Uses bespoke AWS hardware + software

• Is a multi-tenant service

• Performs AES256 operations

• API for crypto command:

– Key Management

– Encryption / Decryption

• Customer selects MasterKey

• Data Key is transported via envelope encryption

Customer Master Key(s)

Data Key 1

Amazon S3 Object

Amazon EBS Volume

Amazon Redshift Cluster

Data Key 2 Data Key 3 Data Key 4

Custom Application

AWS KMS

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AWS Key Management Service II

Reference Architecture

Application or AWS Service

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Data Key Encrypted Data Key Encrypted

Data

Master Key(s) in Customer’s Account

AWS

Key Management Service

1. Application or AWS service client requests an encryption key to use to encrypt data, and passes a reference to a master key under the account.

2. Client request is authenticated based on whether they have access to use the master key.

3. A new data encryption key is created and a copy of it is encrypted under the master key.

4. Both data key and encrypted data key are returned to the client. Data key is used to encrypt customer data and then deleted as soon as is practical.

5. Encrypted data key is stored for later use and sent back to AWS KMS when the source data needs to be decrypted.

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S3 (normal mode)

AWS AZ

• Data is sent to S3 encrypted

• S3 stores the data unencrypted

• Data travels unencrypted between AZs

• Enforce https:

{

"Statement": [{

"Effect": "Deny”,

"Action": "s3:*",

"Condition": {

"Bool": { "aws:SecureTransport": false } },

"Resource": "arn:aws:s3:::bucket/*"

]}

}

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S3 (server-side encryption)

AWS AZ

• S3 encrypts data with AWS owned key

• Data travels encrypted between AZs

• Data at rest is encrypted with AWS-owned key

• Enforce at-rest encryption:

{

"Statement":[{

"Sid":"DenyUnEncryptedObjectUploads",

"Effect":"Deny",

"Principal":"*",

"Action":"s3:PutObject",

"Resource":"arn:aws:s3:::YourBucket/*",

"Condition":{

"StringNotEquals":{

"s3:x-amz-server-side-encryption":"AES256"

} } } ] }

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S3 (server-side, user key)

AWS AZ

• S3 encrypts data with customer key sent in request

– The key will be forgotten by AWS immediatelly

• Data travels encrypted between Azs

• Data at rest is encrypted with customer-owned key

• Customer needs to send key in GET request

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S3 (server-side, user key + KMS)

AWS AZ

• S3 encrypts data with key sent in request

• Key remains in KMS

IAM KMS

Object

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S3 (client-side encryption)

AWS AZ

• Client encrypts the data locally with local held key

• AWS never sees the key

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EBS (normal mode)

AWS AZ

• Instance sends data to volume via hypervisor module

– Module can encrypt or not, depending on customer choice

– Data travels to the disks and between datacentres, potentially unencrypted – Data lives unencrypted on Disk

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EBS (server-side encryption)

AWS AZ

• Instance sends encrypted data over hypervisor to volume

– Instance OS needs to support encryption

– Data travels encrypted to the disks and between datacentres – Data lives encrypted on Disk

– AWS owns key/algorithm/data

– Included in scope of AWS SOC1 report

IAM KMS

Volume

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CloudHSM

• Tamper-Proof and Tamper-Evident

– Destroys its stored keys if under attack

• FIPS 140-2 Level 2 certified

• Base position is to be a Keystore

• Can also be used to timestamp documents

• You can send data for encrypt / decrypt

– Key never does leave the HSM

– Can be used by several commecial software – Can be used by API access the HSM

• Needs to be backed-up (ideally to HSM on customer premises)

• Can be (and should) be combined in HA clusters

• Is NOT a key management system

– but can work with some third-party ones

• Communicates via:

– PKCS#11 – JCE

• Some applications need a “plugin”

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Redshift can use CloudHSM

• When using CloudHSM

– Redshift gets cluster key from HSM

– Redshift generates a database key and encrypts it with the cluster key from the CloudHSM

– Redshift encrypts data with the database key – Redshift supports re-encryption

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RDS Crypto Support

• RDS / Oracle can use CloudHSM to store keys for Oracle Wallet

– So TDE can be HSM-backed

• RDS / MySQL, RDS / Postgres can use KMS to manage keys used to encrypt underlying EBS volumes

– So all tables are encrypted at rest

• Note that in-memory database contents (once the database has been unlocked) are cleartext

– RAM encryption is not something AWS has today, but it has been done in other contexts

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VPC VGW

• Hardware IPsec termination points

• Data on the VPC side of the VGW is unprotected by the VGW (no re-encryption)

– If you need VPN termination with onward re-encryption, use EC2 instances with OpenSWAN or Cisco CRSs instead…

• Uses pre-shared symmetric key

• The Key is a shared one between AWS and the customer

AWS AZ AWS AZ

Customer

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Between Regions

Availability Zone

Availability Zone Public

Customer WAN

DX Site DX Site

Custome r DC

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Others

• Glacier

– Archives have always been encrypted – this is entirely transparent to the user – Glacier keys are AES256

– AWS holds key/algorithm/data

• Route53

– Supports signed zones

• ELB

– Supports SSL termination including onward re-encryption and customer choice of cipher suite (useful post-POODLE)

– AWS holds keys/algorithm/data

– Unidirectional trust only (no certificate-based authentication of client to server)

• Import/Export

– Currently relies on Truecrypt shared secret between customer and AWS for exporting data

– Truecrypt has not been broken, but it is not longer maintained. Therefore import/export will choose another option

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Bertram Dorn

Amazon Web Services Germany GmbH

[email protected]

Additional Ressources:

http://aws.amazon.com/documentation http://aws.amazon.com/compliance http://aws.amazon.com/security

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