[role="xpack"]
[[configuring-saml-realm]]
=== Configuring a SAML realm

The {stack} supports Security Assertion Markup Language Single Sign On (SAML SSO) 
into {kib} with {es} as a backend service. In particular, the {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 {stack} is operating as a _service provider_ (SP). For more 
information, see {stack-ov}/saml-realm.html[SAML authentication] and 
{stack-ov}/saml-guide.html[Configuring SAML SSO on the {stack}]. 

[NOTE]
--

* If you configure a SAML realm for use in {kib}, 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 {es} and add the {stack} as a service provider:

. Enable SSL/TLS for HTTP. 
+
--
If your {es} cluster is operating in production mode, you must
configure the HTTP interface to use TLS before you can enable SAML 
authentication.

See <<tls-http>>.
--

. Enable the Token Service. 
+
--
The {es} SAML implementation makes use of the {es} 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:

[source, yaml]
------------------------------------------------------------
xpack.security.authc.token.enabled: true
------------------------------------------------------------
--

. Configure a SAML IdP metadata file. 
+
--
The {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 {stack} requires. For more information, see 
{stack-ov}/saml-guide-idp.html[The identity provider].
--

.. Download the IdP metadata document and store it within the `config` directory 
on each {es} node. For example, store it as `config/saml/idp-metadata.xml`.

.. 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.
--

. Create one or more SAML realms.
+
--
SAML authentication is enabled by configuring a SAML realm within the
authentication chain for {es}.

This realm has a few mandatory settings, and a number of optional settings.
The available settings are described in detail in the
<<ref-saml-settings>>. The following settings (in the `elasticsearch.yml` 
configuration file) are the most common settings:

[source, yaml]
------------------------------------------------------------
xpack.security.authc.realms:
  saml: <1>
    saml1: <2>
      order: 2 <3>
      idp.metadata.path: saml/idp-metadata.xml <4>
      idp.entity_id: "https://sso.example.com/" <5>
      sp.entity_id:  "https://kibana.example.com/" <6>
      sp.acs: "https://kibana.example.com/api/security/v1/saml" <7>
      sp.logout: "https://kibana.example.com/logout" <8>
------------------------------------------------------------
<1> The realm must be within the `xpack.security.authc.realms.saml` namespace.
<2> This setting defines a new authentication realm named "saml1". For an 
introduction to realms, see {stack-ov}/realms.html[Realms]. 
<3>  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).
<4> 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. {security} 
automatically monitors this file for changes and reloads the configuration 
whenever it is updated.
<5> This is the identifier (SAML EntityID) that your IdP uses. It should match 
the `entityID` attribute within the metadata file.
<6> This is a unique identifier for your {kib} instance, expressed as a URI.
You will use this value when you add {kib} as a service provider within your IdP.
We recommend that you use the base URL for your {kib} instance as the entity ID.
<7> The Assertion Consumer Service (ACS) endpoint is the URL within {kib} 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 {kib}; it does not need to be 
directly accessible by {es} or the IdP. The correct value can vary depending on 
how you have installed {kib} 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 {kib} instance.
<8> This is the URL within {kib} 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 {es} or the IdP. The correct value can 
vary depending on how you have installed {kib} and whether there are any
proxies involved, but it will typically be +$\{kibana-url}/logout+ where
_$\{kibana-url}_ is the base URL for your {kib} instance.

IMPORTANT: SAML is used when authenticating via {kib}, but it is not an
effective means of authenticating directly to the {es} 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 
{stack-ov}/saml-guide-authentication.html#saml-create-realm[Create a SAML realm].
--

. Add attribute mappings. 
+
--
When a user connects to {kib} 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:
--
.. 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.

.. Read through the list of user properties that {es} 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.

.. Configure your IdP to release those attributes to your {kib} 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 {es} service is entirely 
configurable and does not require that any specific URIs are used.
--

.. Configure the SAML realm to associate the {es} user properties to the URIs 
that you configured in your IdP. 
+
--
For example, add the following settings to the `elasticsearch.yml` configuration 
file:

[source, yaml]
------------------------------------------------------------
xpack.security.authc.realms.saml.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 
{stack-ov}/saml-guide-authentication.html#saml-attribute-mapping[Attribute mapping]. 
--

. (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 
{stack-ov}/saml-guide-authentication.html#saml-logout[SAML logout]. 
--

. (Optional) Configure encryption and signing.
+
--
The {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 {es} for signing, encryption, or both, with the same or 
separate keys. For more information, see 
{stack-ov}/saml-guide-authentication.html#saml-enc-sign[Encryption and signing]. 
--

. (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 {stack} by 
using the <<saml-metadata,`elasticsearch-saml-metadata` command>>.
--

. Configure role mappings.
+
--
When a user authenticates using SAML, they are identified to the {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 {security}
roles. See {stack-ov}/saml-role-mapping.html[Configuring role mappings]. 

NOTE: The SAML realm supports
{stack-ov}/realm-chains.html#authorization_realms[authorization realms] as an
alternative to role mapping.

--

. {stack-ov}/saml-kibana.html[Configure {kib} to use SAML SSO]. 

