spring-authorization-server

Pros of Spring Security

• Broader scope, covering various security aspects beyond authorization
• More mature and established project with extensive documentation
• Wider community support and ecosystem integration

Cons of Spring Security

• Can be complex to configure for specific use cases
• Heavier footprint due to its comprehensive feature set
• May require more setup for OAuth 2.0 and OpenID Connect scenarios

Code Comparison

Spring Security (basic configuration):

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests().anyRequest().authenticated().and().formLogin();
    }
}

Spring Authorization Server (basic configuration):

@Configuration
@Import(OAuth2AuthorizationServerConfiguration.class)
public class AuthorizationServerConfig {
    @Bean
    public RegisteredClientRepository registeredClientRepository() {
        // Configure registered clients
    }
}

Spring Security provides a more general security configuration, while Spring Authorization Server focuses specifically on OAuth 2.0 and OpenID Connect implementation. Spring Security requires more explicit configuration for various security aspects, whereas Spring Authorization Server offers a more streamlined setup for authorization server functionality.

Pros of Keycloak

• More comprehensive out-of-the-box features, including user management and identity brokering
• Supports multiple protocols (OpenID Connect, SAML, OAuth 2.0) natively
• Offers a user-friendly admin console for easier configuration and management

Cons of Keycloak

• Heavier resource footprint, potentially less suitable for lightweight applications
• Steeper learning curve due to its extensive feature set
• Less seamless integration with Spring ecosystem compared to Spring Authorization Server

Code Comparison

Spring Authorization Server:

@Bean
public SecurityFilterChain authorizationServerSecurityFilterChain(HttpSecurity http) throws Exception {
    OAuth2AuthorizationServerConfiguration.applyDefaultSecurity(http);
    return http.formLogin(Customizer.withDefaults()).build();
}

Keycloak:

@Override
protected void configure(HttpSecurity http) throws Exception {
    super.configure(http);
    http.authorizeRequests()
        .antMatchers("/customers*").hasRole("USER")
        .antMatchers("/admin*").hasRole("ADMIN")
        .anyRequest().permitAll();
}

Both repositories provide robust authorization server implementations, but they cater to different use cases. Spring Authorization Server is more lightweight and integrates seamlessly with the Spring ecosystem, while Keycloak offers a more comprehensive identity and access management solution with additional features and protocols support.

Pros of CAS

• More comprehensive feature set, including multi-factor authentication and advanced ticketing mechanisms
• Longer history and wider adoption in enterprise environments
• Extensive documentation and community support

Cons of CAS

• Steeper learning curve due to its complexity and extensive features
• Potentially heavier resource consumption compared to Spring Authorization Server

Code Comparison

CAS (Groovy configuration):

cas.authn.accept.users=casuser::Mellon
cas.service-registry.json.location=file:/etc/cas/services
cas.authn.mfa.global-provider-id=mfa-duo

Spring Authorization Server (Java configuration):

@Bean
public RegisteredClientRepository registeredClientRepository() {
    RegisteredClient registeredClient = RegisteredClient.withId(UUID.randomUUID().toString())
            .clientId("client")
            .clientSecret("{noop}secret")
            .clientAuthenticationMethod(ClientAuthenticationMethod.CLIENT_SECRET_BASIC)
            .authorizationGrantType(AuthorizationGrantType.AUTHORIZATION_CODE)
            .redirectUri("http://127.0.0.1:8080/login/oauth2/code/client")
            .scope("openid")
            .build();
    return new InMemoryRegisteredClientRepository(registeredClient);
}

Pros of JJWT

• Lightweight and focused solely on JWT operations
• Easy to integrate into existing projects without additional dependencies
• Supports a wide range of cryptographic algorithms

Cons of JJWT

• Lacks built-in OAuth 2.0 and OpenID Connect support
• Requires manual implementation of security features and token management
• Limited to JWT-specific functionality

Code Comparison

JJWT:

String jws = Jwts.builder()
    .setSubject("user123")
    .signWith(SignatureAlgorithm.HS256, key)
    .compact();

Spring Authorization Server:

OAuth2AccessTokenResponseClient<OAuth2AuthorizationCodeGrantRequest> accessTokenResponseClient =
    new DefaultAuthorizationCodeTokenResponseClient();
OAuth2AccessTokenResponse tokenResponse = accessTokenResponseClient.getTokenResponse(authorizationCodeGrantRequest);

Summary

JJWT is a lightweight library focused on JWT operations, making it easy to integrate into existing projects. It supports various cryptographic algorithms but lacks built-in OAuth 2.0 and OpenID Connect support.

Spring Authorization Server provides a comprehensive OAuth 2.0 and OpenID Connect solution, offering more robust security features and token management. However, it may be overkill for projects that only require simple JWT functionality.

Choose JJWT for straightforward JWT operations in existing projects, and Spring Authorization Server for full-fledged OAuth 2.0 and OpenID Connect implementations.

Pros of java-jwt

• Lightweight and focused solely on JWT handling
• Easy to integrate into existing projects without additional dependencies
• Supports various algorithms for JWT signing and verification

Cons of java-jwt

• Limited to JWT operations, lacking comprehensive authorization server features
• Requires manual implementation of token issuance, validation, and management
• No built-in support for OAuth 2.0 flows or OpenID Connect

Code Comparison

spring-authorization-server:

@Bean
public RegisteredClientRepository registeredClientRepository() {
    RegisteredClient registeredClient = RegisteredClient.withId(UUID.randomUUID().toString())
            .clientId("client")
            .clientSecret("{noop}secret")
            .clientAuthenticationMethod(ClientAuthenticationMethod.CLIENT_SECRET_BASIC)
            .authorizationGrantType(AuthorizationGrantType.AUTHORIZATION_CODE)
            .redirectUri("http://127.0.0.1:8080/login/oauth2/code/client")
            .scope(OidcScopes.OPENID)
            .build();
    return new InMemoryRegisteredClientRepository(registeredClient);
}

java-jwt:

Algorithm algorithm = Algorithm.HMAC256("secret");
String token = JWT.create()
        .withIssuer("auth0")
        .withClaim("username", "john.doe")
        .withExpiresAt(new Date(System.currentTimeMillis() + 10 * 60 * 1000))
        .sign(algorithm);

The spring-authorization-server example showcases client registration for OAuth 2.0, while java-jwt demonstrates simple JWT creation and signing.