Configuring a SAML realmedit

The Elastic Stack supports Security Assertion Markup Language Single Sign On (SAML SSO) into Kibana with Elasticsearch as a backend service. In particular, the Elastic Stack supports the SAML 2.0 Web Browser SSO and the SAML 2.0 Single Logout profiles. It can integrate with any identity provider (IdP) that supports at least the SAML 2.0 Web Browser SSO Profile.

In SAML terminology, the Elastic Stack is operating as a service provider (SP). For more information, see SAML authentication and Configuring SAML SSO on the Elastic Stack.

Note
  • If you configure a SAML realm for use in Kibana, you should also configure another realm, such as the native realm in your authentication chain.
  • These instructions assume that you have an existing SAML identity provider.

To enable SAML authentication in Elasticsearch and add the Elastic Stack as a service provider:

  1. Enable SSL/TLS for HTTP.

    If your Elasticsearch cluster is operating in production mode, you must configure the HTTP interface to use TLS before you can enable SAML authentication.

    See Encrypting HTTP Client Communications.

  2. Enable the Token Service.

    The Elasticsearch SAML implementation makes use of the Elasticsearch Token Service. This service is automatically enabled if you configure TLS on the HTTP interface. You can explicitly enable it by including the following setting in your elasticsearch.yml file:

    xpack.security.authc.token.enabled: true
  3. Configure a SAML IdP metadata file.

    The Elastic Stack uses a standard SAML metadata document in XML format, which defines the capabilities and features of your identity provider. You should be able to download or generate such a document within your IdP administration interface.

    Most IdPs will provide an appropriate metadata file with all the features that the Elastic Stack requires. For more information, see The identity provider.

    1. Download the IdP metadata document and store it within the config directory on each Elasticsearch node. For example, store it as config/saml/idp-metadata.xml.
    2. Get the identifier for your identity provider.

      The IdP will have been assigned an identifier (EntityID in SAML terminology), which is most commonly expressed in Uniform Resource Identifier (URI) form. Your admin interface might tell you what this is or you might need to read the metadata document to find it. Look for the entityID attribute on the EntityDescriptor element.

  4. Create one or more SAML realms.

    SAML authentication is enabled by configuring a SAML realm within the authentication chain for Elasticsearch.

    This realm has a few mandatory settings, and a number of optional settings. The available settings are described in detail in the SAML realm settingsedit. The following settings (in the elasticsearch.yml configuration file) are the most common settings:

    xpack.security.authc.realms.saml1: 
      type: saml 
      order: 2 
      idp.metadata.path: saml/idp-metadata.xml 
      idp.entity_id: "https://sso.example.com/" 
      sp.entity_id:  "https://kibana.example.com/" 
      sp.acs: "https://kibana.example.com/api/security/v1/saml" 
      sp.logout: "https://kibana.example.com/logout" 

    This setting defines a new authentication realm named "saml1". For an introduction to realms, see Realms.

    The type must be saml.

    You should define a unique order on each realm in your authentication chain. It is recommended that the SAML realm be at the bottom of your authentication chain (that is, it has the highest order).

    This is the path to the metadata file that you saved for your identity provider. The path that you enter here is relative to your config/ directory. X-Pack security automatically monitors this file for changes and reloads the configuration whenever it is updated.

    This is the identifier (SAML EntityID) that your IdP uses. It should match the entityID attribute within the metadata file.

    This is a unique identifier for your Kibana instance, expressed as a URI. You will use this value when you add Kibana as a service provider within your IdP. We recommend that you use the base URL for your Kibana instance as the entity ID.

    The Assertion Consumer Service (ACS) endpoint is the URL within Kibana that accepts authentication messages from the IdP. This ACS endpoint supports the SAML HTTP-POST binding only. It must be a URL that is accessible from the web browser of the user who is attempting to login to Kibana; it does not need to be directly accessible by Elasticsearch or the IdP. The correct value can vary depending on how you have installed Kibana and whether there are any proxies involved, but it is typically ${kibana-url}/api/security/v1/saml where ${kibana-url} is the base URL for your Kibana instance.

    This is the URL within Kibana that accepts logout messages from the IdP. Like the sp.acs URL, it must be accessible from the web browser, but does not need to be directly accessible by Elasticsearch or the IdP. The correct value can vary depending on how you have installed Kibana and whether there are any proxies involved, but it will typically be ${kibana-url}/logout where ${kibana-url} is the base URL for your Kibana instance.

    Important

    SAML is used when authenticating via Kibana, but it is not an effective means of authenticating directly to the Elasticsearch REST API. For this reason we recommend that you include at least one additional realm such as the native realm in your authentication chain for use by API clients.

    For more information, see Create a SAML realm.

  5. Add attribute mappings.

    When a user connects to Kibana through the identity provider, the IdP supplies a SAML assertion that includes attributes for the user. You can configure the SAML realm to map these attributes to properties on the authenticated user.

    The recommended steps for configuring these SAML attributes are as follows:

    1. Consult your IdP to see what user attributes it can provide. This varies greatly between providers, but you should be able to obtain a list from the documentation or from your local admin.
    2. Read through the list of user properties that Elasticsearch supports and decide which of them are useful to you and can be provided by your IdP. At a minimum, the principal attribute is required. The groups attribute is recommended.
    3. Configure your IdP to release those attributes to your Kibana SAML service provider.

      This process varies by provider - some provide a user interface for this, while others might require that you edit configuration files. Usually the IdP (or your local administrator) have suggestions about what URI to use for each attribute. You can simply accept those suggestions, as the Elasticsearch service is entirely configurable and does not require that any specific URIs are used.

    4. Configure the SAML realm to associate the Elasticsearch user properties to the URIs that you configured in your IdP.

      For example, add the following settings to the elasticsearch.yml configuration file:

      xpack.security.authc.realms.saml1:
        ...
        attributes.principal: "urn:oid:0.9.2342.19200300.100.1.1"
        attributes.groups: "urn:oid:1.3.6.1.4.1.5923.1.5.1."

      For more information, see Attribute mapping.

  6. (Optional) Configure logout services.

    The SAML protocol supports the concept of Single Logout (SLO). The level of support for SLO varies between identity providers.

    For more information, see SAML logout.

  7. (Optional) Configure encryption and signing.

    The Elastic Stack supports generating signed SAML messages (for authentication and/or logout), verifying signed SAML messages from the IdP (for both authentication and logout), and processing encrypted content.

    You can configure Elasticsearch for signing, encryption, or both, with the same or separate keys. For more information, see Encryption and signing.

  8. (Optional) Generate service provider metadata.

    There are some extra configuration steps that are specific to each identity provider. If your identity provider can import SP metadata, some of those steps can be automated or expedited. You can generate SP metadata for the Elastic Stack by using the elasticsearch-saml-metadata command.

  9. Configure role mappings.

    When a user authenticates using SAML, they are identified to the Elastic Stack, but this does not automatically grant them access to perform any actions or access any data.

    Your SAML users cannot do anything until they are mapped to X-Pack security roles. See Configuring role mappings.

  10. Configure Kibana to use SAML SSO.