© 2017, Amazon Web Services, Inc. or its Affiliates. All rights reserved.

Justin Pirtle, AWS Solutions Architect

07/25/17

Security Best Practices for

Serverless Applications

Agenda

• What is Serverless?

• Overview of AWS Lambda, API Gateway, and Cognito

• Securing Serverless microservices

• Auditing and logging

• Summary

No servers to provision

or manage

Scales with usage

Never pay for idle Availability and fault

tolerance built in

Serverless means…

Serverless is real

Microservices

AWS Lambda + Amazon API Gateway is the

easiest way to create microservices

• Event handlers one function per event type

• Serverless backends one function per API / path

• Data processing one function per data type

Serverless Microservice

Internet

Mobile

apps

Websites

Partner

Services

AWS

Lambda

AWS Lambda Programming Model

Bring your own code

• Node.js, Java, Python, C#

• Bring your own libraries

(even native ones)

Simple resource model

• Select power rating from

128 MB to 1.5 GB

• CPU and network allocated

proportionately

• Pay only for what compute

you consume

Programming model

• AWS SDK built in (Python

and Node.js)

• Lambda is the “webserver”

• Use processes, threads,

/tmp, sockets normally

Stateless

• Persist data using Amazon

DynamoDB, S3, or

ElastiCache

• No affinity to infrastructure

(can’t “log in to the box”)

Serverless Microservice

Internet

Mobile

apps

Websites

Partner

Services

AWS

Lambda

API

GatewayAmazon

DynamoDB

Introduction to Amazon API Gateway

Create a unified

API frontend for

multiple micro-

services

Authenticate and

authorize

requests to a

backend

DDoS protection

and throttling for

your backend

Throttle, meter,

and monetize API

usage by 3rd

party developers

Amazon API Gateway: Serverless APIs

Internet

Mobile

apps

Websites

Partner

Services

AWS Lambda

functions

API

Gateway

response

cache

Endpoints on

Amazon EC2

Any publicly

accessible

endpoint

Amazon

CloudWatch

Amazon

CloudFront

API

Gateway

Serverless Microservice

Internet

Mobile

apps

Websites

Partner

Services

AWS

Lambda

API

GatewayAmazon

DynamoDB

Identity is mission critical for your applications

SecurityRevenue

Generation

Application

Backbone

Know your users

Monitor engagement

with your application

Store and manage

user data

Personalize your

users’ experiences

Protect sensitive data

Secure business-

critical processes

User Identity

Developing Auth Infrastructure is Difficult

• Need to develop a reliable user directory to manage identities

• Handling user data and passwords and protecting privacy

• Prioritizing scalability of your infrastructure upfront

• Implementing token-based authentication

• Support for multiple social identity providers

• Federation with corporate directories for B2E applications

1

2

3

5

6

4

Amazon Cognito Identity

Facebook

Corporate

OIDC

Sign in with

Your User Pools

You can easily and securely add sign-up

and sign-in functionality to your mobile and

web apps with a fully-managed service that

scales to support 100s of millions of users.

Federated Identities

Your users can sign in with third-party

identity providers, such as Facebook and

SAML providers, and you can control

access to AWS resources from your app.

SAML

Sign in

Username

Password

Submit

Comprehensive Support for Identity Use Cases

Serverless Microservice

Internet

Mobile

apps

Websites

Partner

Services

AWS

Lambda

API

GatewayAmazon

DynamoDB

Amazon

Cognito

Securing Serverless

microservices

Securing AWS Lambda

Lambda execution models

Synchronous (push) Asynchronous (event) Stream-based

Amazon

API Gateway

AWS Lambda

function

Amazon

DynamoDBAmazon

SNS

/order

AWS Lambda

function

Amazon

S3

reqs

Amazon

Kinesis

changes

AWS Lambda

service

function

The push model and resource policies

Function (resource) policy

• Permissions you grant to your Lambda

function determine which service or

event source can invoke your function

• Resource policies make it easy to

grant cross-account permissions to

invoke your Lambda function

The pull model and IAM roles

IAM execution role

• Permissions you grant to this role

determine what your AWS Lambda

function can do at run-time

• If event source is Amazon DynamoDB

or Amazon Kinesis, then add read

permissions in IAM role

Lambda function security – best practices

Application Security Best practices still apply

(mandatory code review, static analysis, etc.)

Use IAM Role per function and don’t be too

permissive – leverage principle of least privilege

Encrypt environment variables and sensitive data

via KMS and Lambda’s encryption helpers

Leverage EC2 SSM Parameter Store for secrets

and configuration management at scale

Lambda vulnerabilities and security scan

Automate security analysis as part of your CI/CD

pipeline

Input validation/sanitization, SQLi, etc. still apply in

Serverless architectures

Continuously scan for vulnerabilities in

dependencies used; can be a step in your CI/CD

pipeline

Securing API Gateway

API Gateway: three types of authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

Custom Identity Providers

AWS IAM authorization

Custom Authorizers

User Pools Authorizers

API Gateway: three types of authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

Custom Identity Providers

AWS IAM authorization

Custom Authorizers

User Pools Authorizers

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

AmazonAPIGateway

User Pools Authorizers

Amazon Cognito

User Pools

Amazon

DynamoDB

Lambdafunction

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

User Pools Authorizers

AmazonAPIGateway

Amazon Cognito

User Pools

Amazon

DynamoDB

Lambdafunction

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

User Pools Authorizers

AmazonAPIGateway

Amazon Cognito

User Pools

Amazon

DynamoDB

Lambdafunction

• Identity

• Access

• Refresh

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

User Pools Authorizers

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

Amazon Cognito

User Pools

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

User Pools Authorizers

4. Validate

Identity token

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

Amazon Cognito

User Pools

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

User Pools Authorizers

5. Invoke API Call

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

Amazon Cognito

User Pools

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

User Pools Authorizers

6. Access

AWS ResourcesAmazon

DynamoDB

Lambdafunction

AmazonAPIGateway

Amazon Cognito

User Pools

API Gateway: three types of authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

Custom Identity Providers

AWS IAM authorization

Custom Authorizers

User Pools Authorizers

IAM-based authorization

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

Amazon Cognito

Federated Identities

Amazon Cognito

User Pools

AWS Identity &

Access Management

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

Amazon Cognito

User Pools

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

IAM-based authorization

Amazon Cognito

Federated Identities

AWS Identity &

Access Management

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

IAM-based authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

AWS Identity &

Access Management

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

3. Request AWS credentials

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

IAM-based authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

AWS Identity &

Access Management

Tro

ttlin

g

Ca

ch

e

Mo

nit

ori

ng

Auth

Mobile app

4. Validate Id token

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

IAM-based authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

AWS Identity &

Access Management

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Auth

Mobile app

5. Temp AWS credentials

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

IAM-based authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

AWS Identity &

Access Management

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Mobile app

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

IAM-based authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

AWS Identity &

Access Management

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Mobile app

Amazon

DynamoDB

Lambdafunction

AmazonAPIGateway

IAM-based authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

AWS Identity &

Access Management

Tro

ttlin

g

Ca

ch

e

Lo

gg

ing

Mo

nit

ori

ng

Mobile app

8. Invoke Lambda

Lambdafunction

AmazonAPIGateway

IAM-based authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

AWS Identity &

Access Management

Amazon

DynamoDB

IAM Policy Detail

{

"Version": "2012-10-17",

"Statement": [

{

"Action": "execute-api:Invoke",

"Effect": ”Allow",

"Resource": "arn:aws:execute-api:*:*:ff5h9tpwfh/*"

},

{

"Action": "execute-api:Invoke",

"Effect": "Deny",

"Resource": "arn:aws:execute-api:*:*:ff5h9tpwfh/*/POST/locations/*"

}

]

}

API Gateway: three types of authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

Custom Identity Providers

AWS IAM authorization

Custom Authorizers

User Pools Authorizers

Custom Authorizer

Lambda function

Auth

Mobile app

Lambdafunction

AmazonAPIGateway

Amazon

DynamoDB

AWS Identity &

Access Management

Custom Authorizers

Custom Authorizer

Lambda function

Mobile app

Lambdafunction

AmazonAPIGateway

Amazon

DynamoDB

AWS Identity &

Access Management

Custom Authorizers

Custom Authorizer

Lambda function

Auth

Mobile app

Lambdafunction

AmazonAPIGateway

Amazon

DynamoDB

AWS Identity &

Access Management

Custom Authorizers

Custom Authorizer

Lambda function

Auth

Mobile app

Lambdafunction

AmazonAPIGateway

Amazon

DynamoDB

AWS Identity &

Access Management

Custom Authorizers

Auth

Mobile app

Lambdafunction

AmazonAPIGateway

Custom Authorizers

Amazon

DynamoDB

4. Check

policy

cache

AWS Identity &

Access Management

Custom Authorizer

Lambda function

Auth

Mobile app

Lambdafunction

AmazonAPIGateway

Custom Authorizers

Amazon

DynamoDB

5. V

alid

ate

to

ken

AWS Identity &

Access Management

Custom Authorizer

Lambda function

Custom Authorizer

Lambda function

Auth

Mobile app

Lambdafunction

AmazonAPIGateway

Custom Authorizers

Amazon

DynamoDB

6. G

en

era

te a

nd

retu

rn

use

r IAM

po

licy AWS Identity &

Access Management

Custom Authorizer

Lambda function

Auth

Mobile app

Lambdafunction

AmazonAPIGateway

Custom Authorizers

Amazon

DynamoDB

AWS Identity &

Access Management

Custom Authorizer

Lambda function

Auth

Mobile app

Lambdafunction

AmazonAPIGateway

Custom Authorizers

Amazon

DynamoDB

8. Invoke Lambda

AWS Identity &

Access Management

Custom Authorizer Lambda

var testPolicy = new AuthPolicy(”userIdentifier", "XXXXXXXXXXXX", apiOptions);

testPolicy.allowMethod(AuthPolicy.HttpVerb.POST, "/locations/*");

testPolicy.allowMethod(AuthPolicy.HttpVerb.DELETE, "/locations/*");

callback(null, testPolicy.getPolicy());

Sample Code

API Gateway: three types of authorization

Amazon Cognito

User Pools

Amazon Cognito

Federated Identities

Custom Identity Providers

AWS IAM authorization

Custom Authorizers

User Pools Authorizers

Throttle

Usage Plans: Throttle specific consumers

Internet

Mobile

apps

Websites

Partner

Services

AWS Lambda

functions

API

Gateway

response

cache

Endpoints on

Amazon EC2

Any publicly

accessible

endpoint

Amazon

CloudWatch

Amazon

CloudFront

API

Gateway

Usage Plans: Quotas and Throttling

• Prevents one customer from consuming all your

backend system’s capacity

• Let’s you decide how to allocate capacity among your

API consumers. Sample plan:

• Professional plan users: 10 TPS, up to 100 calls / day

• Premium plan users: 100 TPS, up to 1000 calls / day

• Enterprise plan users: 500 TPS, no limit on calls / day

Set daily

quota

Usage Plans: Enforce per-consumer quotas

Internet

Mobile

apps

Websites

Partner

Services

AWS Lambda

functions

API

Gateway

response

cache

Endpoints on

Amazon EC2

Any publicly

accessible

endpoint

Amazon

CloudWatch

Amazon

CloudFront

API

Gateway

Example Serverless

Architecture

Amazon API

GatewayAWS

Lambda

Amazon

DynamoDB

Amazon

S3Amazon

CloudFront

• Bucket Policies

• ACLs

• Geo-Restriction

• Private Content

• DDOS

AuthZ

Serverless app security

• Throttling

• Caching

• Usage Plans

Browser

• Invocation

Policies

• Execution Roles

• Secure

Parameters

• IAM Fine-

grained Access

Control

Audit and log your Serverless

application

Cloudwatch – Log streaming and metrics

Leverage built-in metrics and alarm on aggregates

(throttling)

Create Custom Metrics via Metric Filter out of logs

Captures Lambda invocation details, and all

logging statement output

Stream and centralize logs from multiple accounts

to Amazon ElasticSearch for near real-time

analysis

built-in custom

Amazon Cloudwatch

Different log categories

AWS infrastructure logs

AWS CloudTrail

Amazon VPC Flow

Logs

AWS service logs

AWS Lambda

Amazon API Gateway

Amazon S3

Amazon CloudFront

Amazon Kinesis

…

Different log categories

AWS infrastructure logs

AWS CloudTrail

Amazon VPC Flow

Logs

AWS service logs

AWS Lambda

Amazon API Gateway

Amazon S3

Amazon CloudFront

Amazon Kinesis

…

Security-related events

AWS CloudTrailRecords AWS API calls for your account

What can you answer using a CloudTrail event?

Who made the API call?

What was the API call?

When was the API call made?

Where was the API call made from and made to?

Which resources were acted upon in the API call?

Supported services:

http://docs.aws.amazon.com/awscloudtrail/latest/userguide/cloudtrail-supported-services.html

AWS Config

• Get inventory of AWS resources

• Discover new and deleted resources

• Record configuration changes continuously

• Get notified when configurations change

Summary

• What is Serverless?

• Overview of AWS Lambda, API Gateway, and Cognito

• Securing Serverless microservices

• Auditing and logging

• Summary

Additional Resources

- Serverless on AWS

- Serverless Computing on AWS

- re:Invent Talks and Webinars

- Serverless Auth: Identity Management

- Add User Sign-in, Management, and Security with Cognito

- Deep Dive on AWS Lambda

- Reference Projects

- Serverless Auth Reference App

- Cognito Angular 2 Quickstart

- Cognito API Gateway Auth Reference

Thank you!