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camunda-community-hub / camunda-platform-7-keycloak

Camunda Keycloak Identity Provider Plugin
Apache License 2.0
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Camunda Platform 7 - Keycloak Identity Provider Plugin

Maven Central Apache License V.2

Keycloak

Keycloak™ (https://www.keycloak.org/) is an Open Source Identity and Access Management platform including advanced features such as User Federation, Identity Brokering and Social Login.

Camunda™ (https://camunda.com/) Platform 7 is perfectly suited to carry out BPM projects in the cloud. Identity management in the cloud, however, often differs from classical approaches. Camunda already provides a generic sample for Single Sign On when using Spring Boot. See https://github.com/camunda-consulting/code/tree/master/snippets/springboot-security-sso. Specific instructions on how to use Spring Boots OAuth2 SSO in combination with this Keycloak Identity Provider Plugin can be found below.

Why this plugin? SSO is sufficient in case you only want authentication but have no further advanced security roles. If one needs to use Camundas IdentityService APIs or wants to see actual Users and Groups show up in Cockpit, a custom IdentityProvider needs to be implemented as well.

This plugin provides the basis for using Keycloak as Identity Management solution and will provide a ReadOnlyIdentityProvider. What you will get is a fully integrated solution for using Keycloak as an Identity Provider in Camunda receiving users and groups from Keycloak. The authorization of these users and groups for Camunda resources itself remains within Camunda. This plugin allows the usage of Keycloak as Identity Provider even without SSO.

Beware: in case you want to use Keycloak's advanced login capabilities for social connections you must configure SSO as well. Password grant exchanges are only supported for Keycloak's internally managed users and users of an LDAP / Keberos User federation. Hence without SSO you will only be able to login with users managed by such connections.

Current version: 7.22.0
Latest tests with: Keycloak 25.0.4, 19.0.3-legacy, Camunda 7.22.0, 7.22.0-ee

Features

Changes in version 7.22.0

Changes in version 7.21.6

Changes in version 7.20.1

With version 7.20.0 Camunda Platform 7 switched to Spring Boot 3.1, JakartaEE 10 and a JDK 17 baseline. The Keycloak Identity Provider Plugin has been updated to support the new baseline versions of it's major dependencies.

Changes in version 7.19.0

New in version 7.18.0

Changes in Version 7.17.0

New in Version 2.2.3:

New in Version 2.2.2:

New in Version 2.2.1:

New in Version 2.2.0:

New in Version 2.1.0:

New in Version 2.0.0:

New in Version 1.5.0:

New in Version 1.4.0:

New in Version 1.3.0:

New in Version 1.2.0:

New in Version 1.1.0:

Version 1.0.0:

Known limitations:

Prerequisites in your Keycloak realm

  1. Keycloak docker images can be found on Keycloak Docker Hub.
  2. Create a new client named camunda-identity-service with access type confidential and service accounts enabled: IdentityServiceSettings Please be aware, that beginning with Keycloak 18, you do not only have to configure a valid redirect URL, but a valid post logout redirect URL as well. To keep things easy values can be the same.
  3. Since Keycloak 20, user queries require an 'openid' scope for OIDC clients. To enable this, create an 'openid' scope under client scopes and add add this the camunda-identity-service client. openid-client-scope.png

  4. In order to use refresh tokens set the "Use Refresh Tokens For Client Credentials Grant" option within the "OpenID Connect Compatibility Modes" section (available in newer Keycloak versions):

    IdentityServiceOptions

  5. Add the roles query-groups, query-users, view-users to the service account client roles of your realm (choose realm-management or master-realm, depending on whether you are using a separate realm or master): IdentityServiceRoles
  6. Your client credentials can be found here: IdentityServiceCredentials
  7. Once you're done with the basic setup you're now ready to manage your users and groups with Keycloak. Please keep in mind, that in order to make the Keycloak Identity Provider work, you will need at least one dedicated Camunda admin group or Camunda admin user in your realm. Whether you create this group/user manually or import it using the LDAP user federation or any other Identity Provider is up to you. KeycloakGroups

Usage with Camunda Spring Boot

Maven Dependencies:

<dependency>
    <groupId>org.camunda.bpm.extension</groupId>
    <artifactId>camunda-platform-7-keycloak</artifactId>
    <version>7.22.0</version>
</dependency>

Add the following class to your Camunda Spring Boot application in order to activate the Keycloak Identity Provider Plugin:

package <your-package>;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import org.camunda.bpm.extension.keycloak.plugin.KeycloakIdentityProviderPlugin;

@Component
@ConfigurationProperties(prefix="plugin.identity.keycloak")
public class KeycloakIdentityProvider extends KeycloakIdentityProviderPlugin {
}

Configuration in application.yaml will then look as follows:

camunda.bpm:
  ...
  authorization:
    enabled: true

plugin.identity.keycloak:
  keycloakIssuerUrl: https://<your-keycloak-server>/auth/realms/<realm-name>
  keycloakAdminUrl: https://<your-keycloak-server>/auth/admin/realms/<realm-name>
  clientId: camunda-identity-service
  clientSecret: 42aa42bb-1234-4242-a24a-42a2b420cde0
  useEmailAsCamundaUserId: true
  administratorGroupName: camunda-admin

Hint: the engine must not create a user upon startup - the plugin is a ReadOnlyIdentityProvider. Hence you must not configure an admin-user for camunda.bpm in your application.yaml. The following configuration will likely cause errors upon startup: 

camunda.bpm:
# DON'T DO THIS
  admin-user:
    id: demo
    password: demo
    firstName: Camunda

The admin-user part must be deleted in order to work properly. The recommended procedure for creating the admin user and admin group in Keycloak is to have the deployment pipeline do this during the environment setup phase.

A list of configuration options can be found below:

Property Description
keycloakIssuerUrl The basic issuer URL of your Keycloak server including the realm.
Sample for master realm: https://<your-keycloak-server>/auth/realms/master
keycloakAdminUrl The admin URL of the Keycloak server REST API including the realm.
Sample for master realm: https://<your-keycloak-server>/auth/admin/realms/master
clientId The Client ID of your application.
clientSecret The Client Secret of your application.
useEmailAsCamundaUserId Whether to use the Keycloak email attribute as Camunda's user ID. Default is false.

This is option is a fallback in case you don't use SSO and want to login using Camunda's web interface with your mail address and not the cryptic internal Keycloak ID. Keep in mind that you will only be able to login without SSO with Keycloak's internally managed users and users managed by the LDAP / Keberos User federation.
useUsernameAsCamundaUserId Whether to use the Keycloak username attribute as Camunda's user ID. Default is false. In the default case the plugin will use the internal Keycloak ID as Camunda's user ID.
useGroupPathAsCamundaGroupId Whether to use the Keycloak unique group path as Camunda's group ID. Default is false. In the default case the plugin will use the internal Keycloak ID as Camunda's group ID.
This flag is particularly useful in case you want to have human readable group IDs and recommended when using groups in Camunda's authorization management.
Since 1.1.0
enforceSubgroupsInGroupQuery Starting with Keycloak version 23 the group query without any other search parameters does not automatically return subgroups within the result. Set this flag to true in case you use subgroups together with Keycloak 23 or higher. Otherwise leave it to the default false and benefit from better performance.
Since 7.21.1
administratorGroupName The name of the administrator group. If this name is set and engine authorization is enabled, the plugin will create group-level Administrator authorizations on all built-in resources.
administratorUserId The ID of the administrator user. If this ID is set and engine authorization is enabled, the plugin will create user-level Administrator authorizations on all built-in resources.
authorizationCheckEnabled If this property is set to true, then authorization checks are performed when querying for users or groups. Otherwise authorization checks are not performed when querying for users or groups. Default: true.
Note: If you have a huge amount of Keycloak users or groups we advise to set this property to false to improve the performance of the user and group query.
maxResultSize Maximum result size of queries against the Keycloak API. Default: 250.

Beware: Setting the parameter to a too low value can lead to unexpected effects. Keep in mind that parts of the filtering takes place on the client side / within the plugin itself. Setting the parameter to a too high value can lead to performance and memory issues.
Since 1.5.0
maxHttpConnections Maximum number HTTP connections for the Keycloak connection pool. Default: 50
disableSSLCertificateValidation Whether to disable SSL certificate validation. Default: false. Useful in test environments.
truststore Optional file path to a truststore file. Default: null. In the default case the default Java truststore will be used.
Since 7.21.3
truststorePassword Optional password for the truststore. Default: null.
Since 7.21.3
proxyUri Optional URI of a proxy to use. Default: null, example: http://proxy:81.
Since 2.0.0
proxyUser Optional username for proxy authentication. Default: null.
Since 2.0.0
proxyPassword Optional password for proxy authentication. Default: null.
Since 2.0.0

Caching options

This is a ReadOnlyIdentityProvider which translates all queries against the Camunda IdentityService in REST queries against Keycloak. Under high load it makes sense to not request the same things again and again, especially since the data of users and groups do not change every second. Therefore this plugin provides an optional cache feature.

User and group query caching

In order to activate caching of user and group queries you have the following options available:

Property Description
cacheEnabled Enable caching of user and group queries to Keycloak to improve performance. Default: false.
Since 2.2.0
maxCacheSize Maximum size of the cache. Least used entries are evicted when this limit is reached. Default: 500.
Since 2.2.0
cacheExpirationTimeoutMin Time (in minutes) after which a cached entry is evicted. Default: 15 minutes.
Since 2.2.0

Besides caching of user and group queries there is another scenario where caching could make sense.

Login caching

Imagine a setup with lots of External Task Clients using HTTP Basic Auth against the Camunda REST API (e.g. set camunda.bpm.run.auth.enabled: true when using Camunda Run). Your External Task Clients then might trigger the IdentityProvider's checkPassword function at high frequency. This function requests a token from Keycloak each time it is called. In case of a successful response the login is treated as valid. High frequency then means requesting lots of tokens - in the worst case all for the same user and before an already delivered token has timed out. Therefore this plugin provides an optional login cache feature as well.

In order to activate the login cache you have the following options available:

Property Description
loginCacheEnabled Enable caching of login / check password requests to Keycloak to improve performance. Not applicable in case of SSO scenarios, but useful e.g. in case of External Tasks clients using HTTP Basic Auth only. Default: false
Since 2.2.3
loginCacheSize Maximum size of the login cache. Least used entries are evicted when this limit is reached. Default: 50.
Since 2.2.3
loginCacheExpirationTimeoutMin Time (in minutes) after which a login cache entry is evicted. Default: 15 minutes.
Since 2.2.3

On the downside this feature bypasses the password grant exchange function of Keycloak until the configured timeout expires. So the choice is yours. Please be aware that the login cache is not applicable for SSO scenarios.

Activating Single Sign On

In this part, we’ll discuss how to activate SSO – Single Sign On – for the Camunda Web App using Spring Boot and Spring Security 5.2.x OAuth 2.0 Client capabilities in combination with this plugin and Keycloak as authorization server.

In order to setup Spring Boot's OAuth2 security add the following Maven dependencies to your project:

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-oauth2-client</artifactId>
</dependency>

What we need is a bridge between Spring Security and Camunda. Hence insert a KeycloakAuthenticationProvider as follows:

/**
  * OAuth2 Authentication Provider for usage with Keycloak and KeycloakIdentityProviderPlugin. 
  */
public class KeycloakAuthenticationProvider extends ContainerBasedAuthenticationProvider {

    @Override
    public AuthenticationResult extractAuthenticatedUser(HttpServletRequest request, ProcessEngine engine) {

        // Extract user-name-attribute of the OAuth2 token
        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        if (!(authentication instanceof OAuth2AuthenticationToken) || !(authentication.getPrincipal() instanceof OidcUser)) {
            return AuthenticationResult.unsuccessful();
        }
        String userId = ((OidcUser)authentication.getPrincipal()).getName();
        if (StringUtils.isEmpty(userId)) {
            return AuthenticationResult.unsuccessful();
        }

        // Authentication successful
        AuthenticationResult authenticationResult = new AuthenticationResult(userId, true);
        authenticationResult.setGroups(getUserGroups(userId, engine));

        return authenticationResult;
    }

    private List<String> getUserGroups(String userId, ProcessEngine engine){
        List<String> groupIds = new ArrayList<>();
        // query groups using KeycloakIdentityProvider plugin
        engine.getIdentityService().createGroupQuery().groupMember(userId).list()
            .forEach( g -> groupIds.add(g.getId()));
        return groupIds;
    }

}

Last but not least add a security configuration and enable OAuth2 SSO:

/**
 * Camunda Web application SSO configuration for usage with KeycloakIdentityProviderPlugin.
 */
@ConditionalOnMissingClass("org.springframework.test.context.junit.jupiter.SpringExtension")
@EnableWebSecurity
@Configuration
public class WebAppSecurityConfig {

    @Bean
    @Order(2)
    public SecurityFilterChain httpSecurity(HttpSecurity http) throws Exception {
        return http
                .csrf(csrf -> csrf
                        .ignoringRequestMatchers(antMatcher("/api/**"), antMatcher("/engine-rest/**")))
                .authorizeHttpRequests(authorize -> authorize
                        .requestMatchers(
                                antMatcher("/assets/**"),
                                antMatcher("/app/**"),
                                antMatcher("/api/**"),
                                antMatcher("/lib/**"))
                        .authenticated()
                        .anyRequest()
                        .permitAll())
                .oauth2Login(withDefaults())
                .build();
    }

    @SuppressWarnings({ "rawtypes", "unchecked" })
    @Bean
    public FilterRegistrationBean containerBasedAuthenticationFilter(){

        FilterRegistrationBean filterRegistration = new FilterRegistrationBean();
        filterRegistration.setFilter(new ContainerBasedAuthenticationFilter());
        filterRegistration.setInitParameters(Collections.singletonMap("authentication-provider", "org.camunda.bpm.extension.keycloak.showcase.sso.KeycloakAuthenticationProvider"));
        filterRegistration.setOrder(201); // make sure the filter is registered after the Spring Security Filter Chain
        filterRegistration.addUrlPatterns("/app/*");
        return filterRegistration;
    }

    // The ForwardedHeaderFilter is required to correctly assemble the redirect URL for OAUth2 login. 
    // Without the filter, Spring generates an HTTP URL even though the container route is accessed through HTTPS.
    @Bean
    public FilterRegistrationBean<ForwardedHeaderFilter> forwardedHeaderFilter() {
        FilterRegistrationBean<ForwardedHeaderFilter> filterRegistrationBean = new FilterRegistrationBean<>();
        filterRegistrationBean.setFilter(new ForwardedHeaderFilter());
        filterRegistrationBean.setOrder(Ordered.HIGHEST_PRECEDENCE);
        return filterRegistrationBean;
    }

    @Bean
    @Order(0)
    public RequestContextListener requestContextListener() {
        return new RequestContextListener();
    }
}

Finally configure Spring Security with your Keycloak Single Page Web App client-id and client-secret in application.yaml as follows:

# Spring Boot Security OAuth2 SSO
spring.security.oauth2:
  client:
    registration:
      keycloak:
        provider: keycloak
        client-id: camunda-identity-service
        client-secret: yyy2121abc21def2121ghi212132121abc21def2121ghi2121eyyy
        authorization-grant-type: authorization_code
        redirect-uri: "{baseUrl}/{action}/oauth2/code/{registrationId}"
        scope: openid, profile, email
    provider:
      keycloak:
        issuer-uri: https://<your-keycloak-server>/auth/realms/camunda
        authorization-uri: https://<your-keycloak-server>/auth/realms/camunda/protocol/openid-connect/auth
        user-info-uri: https://<your-keycloak-server>/auth/realms/camunda/protocol/openid-connect/userinfo
        token-uri: https://<your-keycloak-server>/auth/realms/camunda/protocol/openid-connect/token
        jwk-set-uri: https://<your-keycloak-server>/auth/realms/camunda/protocol/openid-connect/certs
        # set user-name-attribute one of: 
        # - sub                -> default; using keycloak ID as camunda user ID
        # - email              -> useEmailAsCamundaUserId=true
        # - preferred_username -> useUsernameAsCamundaUserId=true
        user-name-attribute: email

Beware: You have to set the parameter user-name-attribute of the spring.security.oauth2.client.provider.keycloak in a way that it matches the configuration of your KeycloakIdentityProviderPlugin:

Keep in mind that Keycloak's email attribute might not always be unique, depending on your setup. Email uniqueness can be configured on a per realm level depending on the setting Login with email.

Quickstart

As a quickstart into using and configuring the plugin we recommend to have a look at the Installation on Camunda Platform Run. You'll find a chapter "Docker Sample Setup" at the end of the README. This is a simple starting point.

If your intention is a complete SSO setup on Kubernetes you'll be more happy with the next reference.

Sample Spring Boot Project with SSO on Kubernetes

A sample project using this plugin including a basic SSO and Kubernetes setup can be found under Camunda Showcase for Spring Boot & Keycloak Identity Provider. See directory examples.

Installation on Apache Tomcat with Shared Process Engine

Even if from an architectural point of view Spring Boot is currently the most recommended approach for cloud scenarios, it is of course possible to install the plugin in other Camunda distributions as well. A description on how to install the plugin on an Apache Tomcat full distribution can be found under Installation on Tomcat. See directory examples.

Installation on Camunda Platform Run

A description on how to install the plugin on Camunda BPM Run can be found under Installation on Camunda BPM Run. See directory examples.

Installation on JBoss/Wildfly

A description on how to install the plugin on a JBoss/Wildfly can be found under Installation on JBoss/Wildfly. See directory examples.

Unit testing the plugin

In order to run the unit tests I have used a local docker setup of Keycloak with docker-compose.yml as follows:

version: "3.9"

services:
  jboss.keycloak:
    image: quay.io/keycloak/keycloak:24.0.3
    restart: unless-stopped
    environment:
      TZ: Europe/Berlin
      DB_VENDOR: h2
      KEYCLOAK_ADMIN: keycloak
      KEYCLOAK_ADMIN_PASSWORD: keycloak1!
      KC_HTTP_RELATIVE_PATH: /auth
    ports:
      - "8443:8443"
      - "8080:8080"
    command:
      - start-dev

For details see documentation on Running Keycloak in a container.

Maven test setup

Running unit tests from Maven requires configuring the details of a running Keycloak server. This can be achieved by setting the following environment variables:

Environment Variable Description
KEYCLOAK_URL Keycloak server URL.
Default value: http://localhost:8080/auth
KEYCLOAK_ADMIN_USER The admin user of the Keycloak server.
Default value: keycloak
KEYCLOAK_ADMIN_PASSWORD The admin password of the Keycloak server.
Default value: keycloak1!
KEYCLOAK_ENFORCE_SUBGROUPS_IN_GROUP_QUERY Wether to enforce subgroup results in group queries when testing with Keycloak >= 23.0.0
Default value: true

In case you choose Keycloak in the new Quarkus distribution, please be aware that /auth has been removed from the default context path. Hence, it is required to change the KEYCLOAK_URL for the tests. Tests run successfully against the Quarkus distribution, in case you start Keycloak in Development mode.

That's it. Have a happy Keycloak experience and focus on what really matters: the core processes of your customer.

Brought to you by:

Accso

Gunnar von der Beck, Accso - Accelerated Solutions GmbH

Resources

Maintainer

License

License: Apache License 2.0