Pros of Spring Security

• Comprehensive security framework with broader scope beyond just OpenID Connect
• Extensive documentation and large community support
• Seamless integration with other Spring projects

Cons of Spring Security

• Steeper learning curve due to its extensive feature set
• May require more configuration for specific OpenID Connect use cases
• Potentially heavier footprint for projects only needing OpenID Connect functionality

Code Comparison

OpenID-Connect-Java-Spring-Server:

@Configuration
@EnableAuthorizationServer
public class OIDCAuthorizationServerConfig extends AuthorizationServerConfigurerAdapter {
    // OpenID Connect specific configuration
}

Spring Security:

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.oauth2Login();
        // Additional security configurations
    }
}

The OpenID-Connect-Java-Spring-Server example focuses specifically on OpenID Connect configuration, while Spring Security provides a more general security setup with OAuth2 login support. Spring Security requires additional configuration for full OpenID Connect implementation but offers more flexibility for various security scenarios.

Pros of CAS

• More comprehensive authentication and authorization solution
• Supports a wider range of protocols and integrations
• Active development with frequent updates and releases

Cons of CAS

• Steeper learning curve due to its extensive feature set
• May be overkill for simpler authentication needs
• Requires more resources to run and maintain

Code Comparison

OpenID-Connect-Java-Spring-Server:

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests().antMatchers("/").permitAll();
    }
}

CAS:

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
            .antMatchers("/cas/**").permitAll()
            .anyRequest().authenticated()
            .and().csrf().disable();
    }
}

The code comparison shows that CAS typically requires more configuration due to its extensive features, while OpenID-Connect-Java-Spring-Server may have a simpler setup for basic authentication scenarios.

Pros of Keycloak

• More comprehensive identity and access management solution with additional features like user federation, identity brokering, and social login
• Active development with frequent updates and a larger community
• Supports multiple protocols beyond OpenID Connect, including SAML and OAuth 2.0

Cons of Keycloak

• Steeper learning curve due to its extensive feature set
• Potentially higher resource consumption for smaller applications
• Less focused on OpenID Connect specifically compared to OpenID-Connect-Java-Spring-Server

Code Comparison

OpenID-Connect-Java-Spring-Server configuration:

@Configuration
public class OpenIDConnectConfig {
    @Bean
    public OIDCProvider oidcProvider() {
        return new OIDCProvider();
    }
}

Keycloak configuration:

@Configuration
public class KeycloakConfig {
    @Bean
    public KeycloakConfigResolver keycloakConfigResolver() {
        return new KeycloakSpringBootConfigResolver();
    }
}

Both projects use Spring-based configuration, but Keycloak's setup is more tailored to its specific implementation and integration with Spring Boot.

Pros of pac4j

• Multi-protocol support: Handles various authentication mechanisms beyond OpenID Connect
• Framework-agnostic: Can be integrated with different Java web frameworks
• Active development and community support

Cons of pac4j

• Steeper learning curve due to its versatility
• May require additional configuration for specific use cases
• Less focused on OpenID Connect compared to MITREid Connect

Code Comparison

MITREid Connect (OpenID Connect specific):

@Configuration
@EnableAuthorizationServer
public class OAuth2AuthorizationServerConfig extends AuthorizationServerConfigurerAdapter {
    // OpenID Connect server configuration
}

pac4j (Multi-protocol support):

Config config = new Config(new Clients(
    new OidcClient(oidcConfiguration),
    new FacebookClient(fbId, fbSecret),
    new TwitterClient(twId, twSecret)
));

MITREid Connect is tailored for OpenID Connect implementations, offering a more straightforward setup for this specific protocol. pac4j, on the other hand, provides a flexible solution for various authentication methods, including OpenID Connect, OAuth, SAML, and more.

While MITREid Connect excels in OpenID Connect scenarios, pac4j's versatility makes it suitable for projects requiring multiple authentication protocols or the flexibility to switch between them. However, this flexibility comes at the cost of a potentially more complex initial setup and configuration process.

Pros of JJWT

• Lightweight and focused solely on JWT creation and parsing
• Easy to integrate into existing projects without additional dependencies
• Extensive documentation and examples for quick implementation

Cons of JJWT

• Lacks built-in OpenID Connect functionality
• Requires additional implementation for complete authentication flows
• No out-of-the-box server setup for identity provider services

Code Comparison

JJWT (JWT creation):

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

OpenID-Connect-Java-Spring-Server (Token endpoint):

@RequestMapping(value = "/token", method = RequestMethod.POST)
public Map<String, Object> getTokens(@RequestParam Map<String, String> parameters) {
    // Token generation logic
}

JJWT focuses on JWT manipulation, while OpenID-Connect-Java-Spring-Server provides a complete OpenID Connect implementation. JJWT offers simplicity for JWT handling, but requires additional work for full authentication flows. OpenID-Connect-Java-Spring-Server provides a comprehensive solution but may be overkill for projects only needing basic JWT functionality.