Extending Keycloak with Custom Providers
Enhancing Identity and Access Management with Tailored Solutions for Authentication, Authorization, and User Management
What is Keycloak?
Keycloak is an open-source identity and access management (IAM) solution that provides organizations with the ability to manage users, their access rights, and authentication. It allows centralized control over access to various applications and services, freeing developers from the need to implement their own authorization and authentication mechanisms. A key feature of Keycloak is its ability to integrate with different systems and support modern security standards, such as OAuth2, OpenID Connect, and SAML.
Keycloak's core functionality includes user, group, and role management, which allows flexible control over who has access to which resources. Users can be imported from existing systems like LDAP, Active Directory, or created manually via a user-friendly web interface. Additionally, Keycloak supports the integration of external authentication providers, such as Google or GitHub, making user login significantly easier.
An important feature of Keycloak is the support for Single Sign-On (SSO) and Single Sign-Out, allowing users to authenticate once for access to multiple applications. This saves time and increases convenience for end-users while reducing the load on support services, as fewer users forget their passwords.
Developer Integration
Keycloak provides an API for integration with various programming languages and platforms, making it a versatile solution for many types of applications, including web applications, mobile applications, and microservices. For developers, both ready-to-use adapters for popular languages and the ability to create custom integrations are available if necessary.
Overview of Keycloak's Out-of-the-Box Features
Keycloak offers a wide range of out-of-the-box capabilities, making it a versatile and easy-to-use tool for identity and access management. One of its key features is support for Single Sign-On (SSO), allowing users to authenticate once and gain access to multiple applications. This significantly enhances the user experience by eliminating the need to re-enter credentials when switching between applications.
Security Protocols
Keycloak supports standard security protocols such as OAuth2, OpenID Connect, and SAML, ensuring compatibility with modern systems and applications. These standards enable secure management of authentication, authorization, and access delegation without the need for manually configuring complex security systems.
User Management
Centralized user and role management allows users to be created, assigned roles and groups, and managed in terms of passwords and other attributes. Keycloak allows integration with existing user directories, such as LDAP or Active Directory, simplifying migration without creating new accounts.
Keycloak also supports multi-factor authentication (MFA), providing an additional layer of security. With this feature, users can configure various login verification methods, including SMS codes, one-time password generator apps, and other methods. This is especially important for protecting against unauthorized access and increasing the overall security of the system.
Customization Options
Keycloak offers extensive customization options. Developers can easily customize the login page appearance, add custom authentication providers, and integrate third-party services. This makes Keycloak a flexible solution capable of adapting to various business needs while maintaining ease of use and configuration for developers and system administrators.
Reasons for Extending Keycloak with Custom Providers
In some cases, the business logic or specific requirements of your project may go beyond the standard capabilities. In such situations, custom providers offer a flexible way to tailor Keycloak to unique tasks. This allows you to extend the platform's functionality by implementing your own solutions that meet your specific needs.
Customizing Authentication Processes
One of the main reasons for creating custom providers is the need to customize authentication processes. For example, standard SSO mechanisms or integration with external providers may not meet your company's specific security or authentication requirements. In such cases, custom providers allow you to develop unique authentication methods, whether through biometric data usage or integration with internal corporate systems.
Integration with Non-Standard Data Sources
Custom providers can also be useful for integrating with non-standard data sources. Although Keycloak supports LDAP and Active Directory "out of the box," you may need to connect to other types of user storage or databases. Creating a custom User Storage Provider allows you to interact with data stored in your own system and add new attributes and parameters to user accounts.
Complex Business Logic
Extending Keycloak with custom providers may also be necessary for handling authorization-related business logic. For example, standard role and access management methods may not cover all the nuances of your business processes. Custom Policy Providers allow you to implement complex authorization rules, such as context-aware permissions, dynamic access rights changes, or integration with external systems to verify user credentials.
Another important reason is the need for event monitoring and handling. Keycloak provides an event listener mechanism, but sometimes more complex event handling is required — for instance, sending notifications, logging to special logs, or activating third-party services. Custom Event Providers can be used to create custom handlers that meet your business logic and requirements.
Custom providers can also be helpful when integrating with internal or legacy systems that require specific logic for authentication and authorization. In such cases, standard providers may not be sufficient, and custom solutions will help maintain system integrity and support older applications without significant changes.
Scalability and Adaptability
Customizing Keycloak with custom providers enhances the scalability and adaptability of the system. You can evolve functionality as your business needs change, adding new components without affecting the core architecture of the system. This allows you to respond more flexibly to new challenges, regulatory changes, security requirements, or integration with new services.
Thus, Keycloak custom providers are a powerful tool for flexible adaptation and extending the platform's functionality. They help solve specific tasks, improve security, integrate non-standard solutions, and provide a high level of control over authentication and authorization processes.
Defining Custom Providers
Custom providers in Keycloak are extensions that allow developers to modify or add functionality beyond the standard features of the platform. They are software modules written in Java that deeply integrate into the Keycloak lifecycle and can intervene in key processes such as authentication, authorization, user management, and event handling. This makes custom providers a powerful tool for adapting the system to specific business needs.
Primary Purpose
The primary purpose of custom providers is to enable the addition of non-standard authentication mechanisms, integration with custom databases, creation of complex authorization rules, and event handling. For example, you can create a provider that interacts with internal databases for user management, adds additional logic when verifying tokens, or implements your own security policy for specific roles or conditions.
Custom providers use the interfaces and abstractions provided by Keycloak, allowing them to integrate with existing functionality without significant changes to the core system. This allows developers to extend Keycloak's capabilities by creating modular and reusable solutions that are easy to deploy and maintain.
Types of Custom Providers in Keycloak
Keycloak supports several types of custom providers, each designed to extend different aspects of the platform's functionality. Understanding these provider types is essential for developers looking to customize Keycloak for their specific needs.
Authentication Providers
Extend or customize the authentication process with methods like multi-factor authentication, biometrics, or integration with external verification services.
User Storage Providers
Connect Keycloak to custom user databases or storage systems beyond the standard LDAP and Active Directory integrations.
Event Listeners/Providers
Respond to system events like login attempts, user creation, or role changes with custom logic such as notifications, logging, or integration with monitoring systems.
Policy Providers
Implement custom authorization rules and policies that go beyond standard role-based access control, such as time-based access or location-dependent permissions.
Authentication Providers
Authentication providers in Keycloak play a key role in the user authentication process. They allow adding various authentication methods, which can include multi-factor authentication (MFA), biometric verification, integration with external services, and more. These providers operate within authentication flows that can be configured by the administrator via the Keycloak admin console.
Each authentication provider can be configured to perform specific steps in the user login process. For example, a provider can verify user data through an external system such as a database or API, or add additional verification for specific users or groups. This allows flexible management of the authentication process, depending on security requirements and business processes.
Application-Specific Authentication
Authentication providers can be developed for specific types of applications, such as mobile apps or APIs, where authentication requirements differ from those of web applications. For example, an API might require token verification or request signatures, whereas a web application might use SSO with multi-factor authentication. Developers can use Keycloak's provided interfaces to create custom providers tailored to the specific needs of the application.
Moreover, custom authentication providers can work in conjunction with other standard authentication methods. For example, you can configure an authentication flow so that users first go through standard password verification and then use a custom provider for additional checks via an external service. This makes the authentication process more flexible and customizable for specific use cases.
User Storage Providers
User storage providers in Keycloak allow interaction with non-standard data stores for managing user accounts. While Keycloak's standard mechanisms integrate with LDAP or Active Directory, there may be times when it's necessary to connect to specialized databases or systems where users are stored. This is where custom user storage providers come into play.
These providers work by communicating with external systems to retrieve user information as well as manage user accounts. For example, a custom provider can be created to work with a proprietary company database where employee information is stored. This eliminates the need to migrate data and allows the continued use of existing infrastructure.
Flexible Data Source Integration
The main advantage of custom user storage providers is that they can be configured to work with any data source, be it SQL, NoSQL databases, REST APIs, or other systems. Customization allows not only retrieving user data but also managing it — creating new users, updating information, or deleting accounts directly through the custom provider.
Custom user storage providers are also useful in cases where additional user attributes or specific business logic related to account management need to be added. For example, if Keycloak's standard attributes are insufficient, a custom provider can add extra fields for users, which are managed through an external data source.
Event Listeners/Providers
Event providers in Keycloak are used to handle various events that occur within the system, such as successful authentication, failed login attempts, creation or deletion of accounts, user data updates, and other important actions. Custom event providers allow developers to respond to these events by adding their own logic or integrating Keycloak with external systems.
Monitoring and Logging
For instance, a common use case for custom event providers is to send notifications to a monitoring or logging system whenever a user successfully or unsuccessfully logs in. These notifications can be sent to systems like Splunk, ELK (Elasticsearch, Logstash, Kibana), or other external services. This allows monitoring user activity and reacting to suspicious actions.
Notification Systems
Another example of usage is integrating with notification systems, where certain events, such as user registration or password updates, trigger notifications via email or SMS. Custom event providers allow flexible management of these processes and enable the connection of any external systems for interaction with Keycloak.
Analytics and Tracking
Event providers can be used to record detailed analytics. For example, a custom provider can track user behavior in the system, log important metrics, and send them to analytics platforms for further analysis. This enables companies to collect data for security analysis or user activity monitoring, which helps improve both system security and user experience.
Policy Providers
Policy providers in Keycloak allow managing user access to resources based on custom rules and conditions. In the default configuration, Keycloak offers basic mechanisms for managing roles and access policies, but sometimes this is not enough to implement complex authorization business logic. In such cases, custom policy providers allow specific access rules to be implemented.
Custom policy providers can use various parameters to decide whether to grant or deny access. For example, a policy can be configured that considers not only the user's role but also their location, the device from which access is being made, and even the time of day. This can be useful for companies that need flexible access control rules to enhance security.
External Decision Systems
Another use case for custom policy providers is integration with external decision-making systems. For example, the provider can send requests to an external system to check whether a user has access rights to a particular resource. This is especially useful in situations where access rights change dynamically based on context or external factors.
Custom policy providers can also be used for more detailed resource access control. For example, you can create a policy that restricts access to resources only to users with specific attributes, such as group membership, age, or subscription status. This enables more flexible and precise access control mechanisms tailored to the application's needs.
Basic Requirements for Creating Custom Providers
To create custom providers in Keycloak, you need to prepare a suitable development environment and perform several basic configurations. This process includes installing the necessary tools and configuring the project to work with the Keycloak API. Below are the key steps and requirements for successful setup.
Installing Java Development Kit (JDK)
Custom providers in Keycloak are written in Java, so you need to install JDK version 8 or higher. It is recommended to use the latest stable version of JDK that is compatible with the version of Keycloak you are working with. Make sure the JDK is set in the system environment variables so that Java commands are accessible from the command line.
Installing Apache Maven
Apache Maven is used to manage dependencies and build the project. Maven makes it easy to add dependencies, such as Keycloak libraries and other necessary components, and automates the build process for your custom provider. Install the latest version of Maven and set up the system variables so that Maven commands are accessible from the command line.
Keycloak Setup
To develop and test custom providers, you need to run a local instance of Keycloak. This can be done by downloading the Keycloak distribution from the official website and running it on your local machine. After starting the Keycloak server, perform the initial setup through the admin console, creating an admin user and configuring a Realm for testing your providers.
Setting Up a Project in Maven
Create a new Maven project using a Java template. In pom.xml, add the necessary dependencies to work with Keycloak, including the Keycloak API and other libraries, such as keycloak-services and keycloak-core. This will provide access to the interfaces and classes required to create custom providers.
1<dependency>
2 <groupId>org.keycloak</groupId>
3 <artifactId>keycloak-services</artifactId>
4 <version>YOUR_KEYCLOAK_VERSION</version>
5 <scope>provided</scope>
6</dependency>With these basic configurations, you are ready to start developing custom providers in Keycloak, which involves creating classes, implementing interfaces, and setting up their integration into the system.
Steps to Create a Project Based on a Maven Template
To develop custom providers in Keycloak, it's convenient to use Maven — a tool for project and dependency management in Java. Below are the steps for creating a Maven project from scratch:
Installing Apache Maven
Before starting to create a project, ensure that Maven is installed on your machine. If it is not installed yet, download and install it from the official Apache Maven website. Verify that Maven is installed correctly by running the following command in the terminal:
1mvn -vCreating a New Project
To create a new project using Maven, execute the following command in the terminal:
1mvn archetype:generate \
2 -DgroupId=com.example.keycloak \
3 -DartifactId=custom-provider \
4 -DarchetypeArtifactId=maven-archetype-quickstart \
5 -DinteractiveMode=falseHere:
groupId=com.example.keycloak— this is a unique identifier for your project (you can replace it with your own).artifactId=custom-provider— the name of the artifact you're creating (you can choose any name for your project).maven-archetype-quickstart— the template that will create the basic structure of the project.
Project Structure
After running the command, a project structure with the necessary directories and files will be created. Navigate to the created project directory with cd custom-provider.
Configuring the pom.xml File
The pom.xml file contains information about the project and its dependencies. Open this file and add the necessary dependencies for working with Keycloak. Example configuration:
1<dependencies>
2 <!-- Keycloak Services Dependency -->
3 <dependency>
4 <groupId>org.keycloak</groupId>
5 <artifactId>keycloak-services</artifactId>
6 <version>YOUR_KEYCLOAK_VERSION</version>
7 <scope>provided</scope>
8 </dependency>
9 <!-- Keycloak Core Dependency -->
10 <dependency>
11 <groupId>org.keycloak</groupId>
12 <artifactId>keycloak-core</artifactId>
13 <version>YOUR_KEYCLOAK_VERSION</version>
14 <scope>provided</scope>
15 </dependency>
16</dependencies>Replace YOUR_KEYCLOAK_VERSION with the current version of Keycloak that you are using in your project.
Compiling and Running the Project
After configuring the `pom.xml` file with dependencies, run the command to build the project:
1mvn clean installThis command will compile your project and prepare it for further development of custom providers for Keycloak.
Now your project is ready for creating custom providers, and you can proceed to develop the classes and logic specific to your application.
Description of Key Classes and Interfaces for Custom Providers
Keycloak provides a wide range of interfaces and classes for creating custom providers, ensuring system flexibility and adaptability. Through them, developers can extend Keycloak's standard functionality, integrate it with external systems, customize authentication and authorization processes, and manage events and access policies.
Provider Interface
One of the fundamental elements for all custom extensions is the org.keycloak.provider.Provider interface. It defines the general structure for any provider, such as authentication, user storage, or event handling. This interface is necessary for managing the lifecycle of the provider, allowing you to control its behavior from initialization to shutdown. The close() method is called when the application shuts down, enabling proper provider termination, such as releasing resources or closing connections.
Provider Factory
To create each provider in Keycloak, a factory is used that implements the ProviderFactory<T extends Provider> interface. It manages the creation of provider instances, their configuration, and initialization. The factory not only creates provider objects but also ensures their correct configuration depending on the environment. The init(Config.Scope config) method is used to load settings from configuration files. This approach allows providers to be flexibly adapted to different environments without code changes, simplifying the deployment and update process.
Authentication Provider Interface
Custom authentication providers in Keycloak are created using the org.keycloak.authentication.AuthenticationProvider interface. It extends the basic provider capabilities and adds specialized methods for managing the authentication process. Such a provider can, for example, implement complex user login scenarios, including multi-factor authentication or integration with external services for authentication. Key methods like authenticate(AuthenticationFlowContext context) and action(AuthenticationFlowContext context) allow the provider to verify user data and control the authentication process.
Authentication providers play a key role in integrating Keycloak with various systems, where unique verification methods may be used. For example, a custom provider may interact with an external corporate security system, ensuring complex multi-level user authentication. This mechanism offers broad opportunities for customizing the login process, making Keycloak a flexible solution for organizations with specific security requirements.
User Storage Provider Interface
For integrating Keycloak with non-standard data sources, the org.keycloak.storage.UserStorageProvider interface is used. It allows developers to connect their own user storage systems, such as databases, APIs, or other external services. While Keycloak natively supports LDAP and Active Directory, a custom provider can connect to any other database. Key methods like getUserById(String id, RealmModel realm) and getUserByUsername(String username, RealmModel realm) allow the custom provider to interact with external storage to find and manage users.
Event Listener Provider Interface
Event providers, implemented using the org.keycloak.events.EventListenerProvider interface, allow responding to various events in Keycloak. These events include successful and failed login attempts, user account updates, password changes, and other actions that may be important for monitoring or processing. A custom provider can set up logic to respond to these events, such as logging them or sending notifications to administrators.
The onEvent(Event event) method in a custom event provider allows performing actions when events occur. For example, you can configure notification sending to monitoring systems for every failed login attempt. This provides flexibility in managing events happening in Keycloak and allows integrating it with external analytics and security systems.
Policy Provider Interface
The org.keycloak.authorization.policy.provider.PolicyProvider interface is used to create custom policy providers responsible for managing resource access. Policies allow defining complex access rules that consider many factors, such as user attributes, time of day, location, or request context. This allows flexible authorization management based on business requirements.
The evaluate(PolicyEnforcementContext context) method provides the ability to create dynamic solutions for access control. Custom policies can make decisions based on data outside Keycloak's standard capabilities. For example, a policy can be created that considers the user's geographic location or the type of device used to access the resource. These additional parameters allow more granular control over resource access.
Thus, Keycloak provides a wide range of interfaces and classes for creating custom providers, ensuring system flexibility and adaptability. Through them, developers can extend Keycloak's standard functionality, integrate it with external systems, customize authentication and authorization processes, and manage events and access policies. These mechanisms allow adapting Keycloak to the most complex business requirements while maintaining system integrity and security.
Conclusion
Despite its comprehensive feature set, there are scenarios where organizations require more than what Keycloak offers by default. In such cases, extending Keycloak with custom providers becomes essential to address specific business needs. Custom providers allow developers to create tailor-made solutions that adapt Keycloak's authentication, authorization, and user management processes to unique project requirements. Whether it's creating custom authentication flows, connecting to proprietary data sources, or adding additional layers of security, custom providers offer the flexibility necessary for complex environments.
Authentication providers, user storage providers, event listeners, and policy providers are some of the key types of custom extensions available in Keycloak. Each of these providers offers developers the ability to deeply integrate with Keycloak's lifecycle and modify processes such as user verification, data management, event handling, and access control. The modular design of Keycloak ensures that custom providers can be added without disrupting the core system, allowing organizations to scale and evolve their IAM solutions as their needs grow.
Development Environment
Developing custom providers in Keycloak requires setting up a suitable development environment, which includes configuring Java Development Kit (JDK), Apache Maven, and Keycloak's API libraries. By following a clear set of steps, developers can create new projects that extend Keycloak's capabilities, ensuring seamless integration with existing corporate infrastructure. This flexibility allows for the continuous evolution of Keycloak-based solutions, as businesses adjust to changing security landscapes or regulatory requirements.