You can configure X-Pack security to use Public Key Infrastructure (PKI) certificates to authenticate users. This requires clients to present X.509 certificates. To use PKI, you configure a PKI realm, enable client authentication on the desired network layers (transport or http), and map the Distinguished Names (DNs) from the user certificates to X-Pack security roles in the role mapping file.
You can also use a combination of PKI and username/password authentication. For
example, you can enable SSL/TLS on the transport layer and define a PKI realm to
require transport clients to authenticate with X.509 certificates, while still
authenticating HTTP traffic using username and password credentials. You can also set
optional to allow clients without
certificates to authenticate with other credentials.
You must enable SSL/TLS and enabled client authentication to use PKI. For more information, see Setting Up SSL/TLS on a Cluster.
Like other realms, you configure options for a
pki realm under the
xpack.security.authc.realms namespace in
Add a realm configuration of type
xpack.security.authc.realmsnamespace. At a minimum, you must set the realm
pki. If you are configuring multiple realms, you should also explicitly set the
orderattribute. See PKI Realm Settings for all of the options you can set for a
For example, the following snippet shows the most basic
xpack: security: authc: realms: pki1: type: pki
With this configuration, any certificate trusted by the SSL/TLS layer is accepted for authentication. The username is the common name (CN) extracted from the DN of the certificate.
When you configure realms in
elasticsearch.yml, only the realms you specify are used for authentication. If you also want to use the
filerealms, you must include them in the realm chain.
If you want to use something other than the CN of the DN as the username, you can specify a regex to extract the desired username. For example, the regex in the following configuration extracts the email address from the DN:
xpack: security: authc: realms: pki1: type: pki username_pattern: "EMAILADDRESS=(.*?)(?:,|$)"
- Restart Elasticsearch.
The PKI realm relies on the SSL settings of the node’s network interface (transport or http). The realm can be configured to be more restrictive than the underlying network connection - that is, it is possible to configure the node such that some connections are accepted by the network interface but then fail to be authenticated by the PKI realm. However the reverse is not possible - the PKI realm cannot authenticate a connection that has been refused by the network interface.
In particular this means:
The transport or http interface must request client certificates by setting
The interface must trust the certificate that is presented by the client
by configuring either the
certificate_authoritiespaths, or by setting
- The protocols supported by the interface must be compatible with those used by the client.
The relevant network interface (transport or http) must be configured to trust any certificate that is to be used within the PKI realm. However it possible to configure the PKI realm to trust only a subset of the certificates accepted by the network interface. This is useful when the SSL/TLS layer trusts clients with certificates that are signed by a different CA than the one that signs your users' certificates.
To configure the PKI realm with its own truststore, specify the
truststore.path option as below:
xpack: security: authc: realms: pki1: type: pki truststore: path: "/path/to/pki_truststore.jks" password: "changeme"
certificate_authorities option may be used as an alternative to the
Indicates the realm type. Must be set to
Indicates the priority of this realm within the realm
chain. Realms with a lower order are consulted first.
Although not required, we recommend explicitly
setting this value when you configure multiple realms.
Indicates whether this realm is enabled or disabled.
Enables you to disable a realm without removing its
configuration. Defaults to
Specifies the regular expression pattern used to extract
the username from the certificate DN. The first match
group is used as the username. Defaults to
List of paths to the PEM encoded certificate files
that should be trusted.
This setting may not be used with
The path to the truststore. Defaults to the path
defined by SSL/TLS settings.
This setting may not be used with
Specifies the password for the truststore. Must be
Specifies the algorithm used for the truststore.
You map roles for PKI users through the role-mapping API, or by using a file stored on each node. When a user authenticates against a PKI realm, the privileges for that user are the union of all privileges defined by the roles to which the user is mapped.
You identify a user by the distinguished name in their certificate.
For example, the following mapping configuration maps
John Doe to the
Using the role-mapping API:
Or, alternatively, configured in a role-mapping file:
The disinguished name for a PKI user follows X.500 naming conventions which
place the most specific fields (like
uid) at the beginning of the
name, and the most general fields (like
dc) at the end of the name.
Some tools, such as openssl, may print out the subject name in a different
One way that you can determine the correct DN for a certificate is to use the
authenticate API (use the relevant PKI
certificate as the means of authentication) and inspect the metadata field in
the result. The user’s distinguished name will be populated under the
key. You can also use the authenticate API to validate your role mapping.
For more information, see Mapping Users and Groups to Roles.