API Security in Action

API Security in Action
contents
preface
acknowledgments
about this book
Who should read this book
How this book is organized: A roadmap
About the code
liveBook discussion forum
Other online resources
about the author
about the cover illustration
Part 1—Foundations
1 What is API security?
1.1 An analogy: Taking your driving test
1.2 What is an API?
1.2.1 API styles
1.3 API security in context
1.3.1 A typical API deployment
1.4 Elements of API security
1.4.1 Assets
1.4.2 Security goals
1.4.3 Environments and threat models
1.5 Security mechanisms
1.5.1 Encryption
1.5.2 Identification and authentication
1.5.3 Access control and authorization
1.5.4 Audit logging
1.5.5 Rate-limiting
Answers to pop quiz questions
Summary
2 Secure API development
2.1 The Natter API
2.1.1 Overview of the Natter API
2.1.2 Implementation overview
2.1.3 Setting up the project
2.1.4 Initializing the database
2.2 Developing the REST API
2.2.1 Creating a new space
2.3 Wiring up the REST endpoints
2.3.1 Trying it out
2.4 Injection attacks
2.4.1 Preventing injection attacks
2.4.2 Mitigating SQL injection with permissions
2.5 Input validation
2.6 Producing safe output
2.6.1 Exploiting XSS Attacks
2.6.2 Preventing XSS
2.6.3 Implementing the protections
Answers to pop quiz questions
Summary
3 Securing the Natter API
3.1 Addressing threats with security controls
3.2 Rate-limiting for availability
3.2.1 Rate-limiting with Guava
3.3 Authentication to prevent spoofing
3.3.1 HTTP Basic authentication
3.3.2 Secure password storage with Scrypt
3.3.3 Creating the password database
3.3.4 Registering users in the Natter API
3.3.5 Authenticating users
3.4 Using encryption to keep data private
3.4.1 Enabling HTTPS
3.4.2 Strict transport security
3.5 Audit logging for accountability
3.6 Access control
3.6.1 Enforcing authentication
3.6.2 Access control lists
3.6.3 Enforcing access control in Natter
3.6.4 Adding new members to a Natter space
3.6.5 Avoiding privilege escalation attacks
Answers to pop quiz questions
Summary
Part 2—Token-based authentication
4 Session cookie authentication
4.1 Authentication in web browsers
4.1.1 Calling the Natter API from JavaScript
4.1.2 Intercepting form submission
4.1.3 Serving the HTML from the same origin
4.1.4 Drawbacks of HTTP authentication
4.2 Token-based authentication
4.2.1 A token store abstraction
4.2.2 Implementing token-based login
4.3 Session cookies
4.3.1 Avoiding session fixation attacks
4.3.2 Cookie security attributes
4.3.3 Validating session cookies
4.4 Preventing Cross-Site Request Forgery attacks
4.4.1 SameSite cookies
4.4.2 Hash-based double-submit cookies
4.4.3 Double-submit cookies for the Natter API
4.5 Building the Natter login UI
4.5.1 Calling the login API from JavaScript
4.6 Implementing logout
Answers to pop quiz questions
Summary
5 Modern token-based authentication
5.1 Allowing cross-domain requests with CORS
5.1.1 Preflight requests
5.1.2 CORS headers
5.1.3 Adding CORS headers to the Natter API
5.2 Tokens without cookies
5.2.1 Storing token state in a database
5.2.2 The Bearer authentication scheme
5.2.3 Deleting expired tokens
5.2.4 Storing tokens in Web Storage
5.2.5 Updating the CORS filter
5.2.6 XSS attacks on Web Storage
5.3 Hardening database token storage
5.3.1 Hashing database tokens
5.3.2 Authenticating tokens with HMAC
5.3.3 Protecting sensitive attributes
Answers to pop quiz questions
Summary
6 Self-contained tokens and JWTs
6.1 Storing token state on the client
6.1.1 Protecting JSON tokens with HMAC
6.2 JSON Web Tokens
6.2.1 The standard JWT claims
6.2.2 The JOSE header
6.2.3 Generating standard JWTs
6.2.4 Validating a signed JWT
6.3 Encrypting sensitive attributes
6.3.1 Authenticated encryption
6.3.2 Authenticated encryption with NaCl
6.3.3 Encrypted JWTs
6.3.4 Using a JWT library
6.4 Using types for secure API design
6.5 Handling token revocation
6.5.1 Implementing hybrid tokens
Answers to pop quiz questions
Summary
Part 3—Authorization
7 OAuth2 and OpenID Connect
7.1 Scoped tokens
7.1.1 Adding scoped tokens to Natter
7.1.2 The difference between scopes and permissions
7.2 Introducing OAuth2
7.2.1 Types of clients
7.2.2 Authorization grants
7.2.3 Discovering OAuth2 endpoints
7.3 The Authorization Code grant
7.3.1 Redirect URIs for different types of clients
7.3.2 Hardening code exchange with PKCE
7.3.3 Refresh tokens
7.4 Validating an access token
7.4.1 Token introspection
7.4.2 Securing the HTTPS client configuration
7.4.3 Token revocation
7.4.4 JWT access tokens
7.4.5 Encrypted JWT access tokens
7.4.6 Letting the AS decrypt the tokens
7.5 Single sign-on
7.6 OpenID Connect
7.6.1 ID tokens
7.6.2 Hardening OIDC
7.6.3 Passing an ID token to an API
Answers to pop quiz questions
Summary
8 Identity-based access control
8.1 Users and groups
8.1.1 LDAP groups
8.2 Role-based access control
8.2.1 Mapping roles to permissions
8.2.2 Static roles
8.2.3 Determining user roles
8.2.4 Dynamic roles
8.3 Attribute-based access control
8.3.1 Combining decisions
8.3.2 Implementing ABAC decisions
8.3.3 Policy agents and API gateways
8.3.4 Distributed policy enforcement and XACML
8.3.5 Best practices for ABAC
Answers to pop quiz questions
Summary
9 Capability-based security and macaroons
9.1 Capability-based security
9.2 Capabilities and REST
9.2.1 Capabilities as URIs
9.2.2 Using capability URIs in the Natter API
9.2.3 HATEOAS
9.2.4 Capability URIs for browser-based clients
9.2.5 Combining capabilities with identity
9.2.6 Hardening capability URIs
9.3 Macaroons: Tokens with caveats
9.3.1 Contextual caveats
9.3.2 A macaroon token store
9.3.3 First-party caveats
9.3.4 Third-party caveats
Answers to pop quiz questions
Summary
Part 4—Microservice APIs in Kubernetes
10 Microservice APIs in Kubernetes
10.1 Microservice APIs on Kubernetes
10.2 Deploying Natter on Kubernetes
10.2.1 Building H2 database as a Docker container
10.2.2 Deploying the database to Kubernetes
10.2.3 Building the Natter API as a Docker container
10.2.4 The link-preview microservice
10.2.5 Deploying the new microservice
10.2.6 Calling the link-preview microservice
10.2.7 Preventing SSRF attacks
10.2.8 DNS rebinding attacks
10.3 Securing microservice communications
10.3.1 Securing communications with TLS
10.3.2 Using a service mesh for TLS
10.3.3 Locking down network connections
10.4 Securing incoming requests
Answers to pop quiz questions
Summary
11 Securing service-to-service APIs
11.1 API keys and JWT bearer authentication
11.2 The OAuth2 client credentials grant
11.2.1 Service accounts
11.3 The JWT bearer grant for OAuth2
11.3.1 Client authentication
11.3.2 Generating the JWT
11.3.3 Service account authentication
11.4 Mutual TLS authentication
11.4.1 How TLS certificate authentication works
11.4.2 Client certificate authentication
11.4.3 Verifying client identity
11.4.4 Using a service mesh
11.4.5 Mutual TLS with OAuth2
11.4.6 Certificate-bound access tokens
11.5 Managing service credentials
11.5.1 Kubernetes secrets
11.5.2 Key and secret management services
11.5.3 Avoiding long-lived secrets on disk
11.5.4 Key derivation
11.6 Service API calls in response to user requests
11.6.1 The phantom token pattern
11.6.2 OAuth2 token exchange
Answers to pop quiz questions
Summary
Part 5—APIs for the Internet of Things
12 Securing IoT communications
12.1 Transport layer security
12.1.1 Datagram TLS
12.1.2 Cipher suites for constrained devices
12.2 Pre-shared keys
12.2.1 Implementing a PSK server
12.2.2 The PSK client
12.2.3 Supporting raw PSK cipher suites
12.2.4 PSK with forward secrecy
12.3 End-to-end security
12.3.1 COSE
12.3.2 Alternatives to COSE
12.3.3 Misuse-resistant authenticated encryption
12.4 Key distribution and management
12.4.1 One-off key provisioning
12.4.2 Key distribution servers
12.4.3 Ratcheting for forward secrecy
12.4.4 Post-compromise security
Answers to pop quiz questions
Summary
13 Securing IoT APIs
13.1 Authenticating devices
13.1.1 Identifying devices
13.1.2 Device certificates
13.1.3 Authenticating at the transport layer
13.2 End-to-end authentication
13.2.1 OSCORE
13.2.2 Avoiding replay in REST APIs
13.3 OAuth2 for constrained environments
13.3.1 The device authorization grant
13.3.2 ACE-OAuth
13.4 Offline access control
13.4.1 Offline user authentication
13.4.2 Offline authorization
Answers to pop quiz questions
Summary
Appendix A—Setting up Java and Maven
A.1 Java and Maven
A.1.1 macOS
A.1.2 Windows
A.1.3 Linux
A.2 Installing Docker
A.3 Installing an Authorization Server
A.3.1 Installing ForgeRock Access Management
A.4 Installing an LDAP directory server
A.4.1 ForgeRock Directory Services
Appendix B—Setting up Kubernetes
B.1 MacOS
B.1.1 VirtualBox
B.1.2 Minikube
B.2 Linux
B.2.1 VirtualBox
B.2.2 Minikube
B.3 Windows
B.3.1 VirtualBox
B.3.2 Minikube
index
A
B
C
D
E
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