elasticsearch/docs/reference/settings/security-settings.asciidoc

[role="xpack"]
[[security-settings]]
=== Security settings in {es}
++++
<titleabbrev>Security settings</titleabbrev>
++++

By default, the {es} {security-features} are disabled when you have a basic or
trial license. To enable {security-features}, use the `xpack.security.enabled`
setting.

You configure `xpack.security` settings  to
<<anonymous-access-settings, enable anonymous access>>
and perform message authentication,
<<field-document-security-settings, set up document and field level security>>,
<<realm-settings, configure realms>>,
<<ssl-tls-settings, encrypt communications with SSL>>, and
<<auditing-settings, audit security events>>.

All of these settings can be added to the `elasticsearch.yml` configuration file,
with the exception of the secure settings, which you add to the {es} keystore.
For more information about creating and updating the {es} keystore, see
<<secure-settings>>.

[float]
[[general-security-settings]]
==== General security settings
`xpack.security.enabled`::
Set to `true` to enable {es} {security-features} on the node. +
+
--
If set to `false`, which is the default value for basic and trial licenses,
{security-features} are disabled. It also affects all {kib} instances that
connect to this {es} instance; you do not need to disable {security-features} in
those `kibana.yml` files. For more information about disabling {security-features}
in specific {kib} instances, see
{kibana-ref}/security-settings-kb.html[{kib} security settings].

TIP: If you have gold or higher licenses, the default value is `true`; we 
recommend that you explicitly add this setting to avoid confusion.  

--

`xpack.security.hide_settings`::
A comma-separated list of settings that are omitted from the results of the
<<cluster-nodes-info,cluster nodes info API>>. You can use wildcards to include
multiple settings in the list.  For example, the following value hides all the
settings for the ad1 active_directory realm:
`xpack.security.authc.realms.active_directory.ad1.*`.
The API already omits all `ssl` settings, `bind_dn`, and `bind_password` due to
the sensitive nature of the information.

`xpack.security.fips_mode.enabled`::
Enables fips mode of operation. Set this to `true` if you run this {es} instance in a FIPS 140-2 enabled JVM.  For more information, see <<fips-140-compliance>>. Defaults to `false`.

[float]
[[password-hashing-settings]]
==== Password hashing settings
`xpack.security.authc.password_hashing.algorithm`::
Specifies the hashing algorithm that is used for secure user credential storage. 
See <<password-hashing-algorithms>>. Defaults to `bcrypt`.

[float]
[[anonymous-access-settings]]
==== Anonymous access settings
You can configure the following anonymous access settings in
`elasticsearch.yml`.  For more information, see <<anonymous-access>>.

`xpack.security.authc.anonymous.username`::
The username (principal) of the anonymous user. Defaults to `_es_anonymous_user`.

`xpack.security.authc.anonymous.roles`::
The roles to associate with the anonymous user. Required.

`xpack.security.authc.anonymous.authz_exception`::
When `true`, an HTTP 403 response is returned if the anonymous user
does not have the appropriate permissions for the requested action. The
user is not prompted to provide credentials to access the requested
resource. When set to `false`, an HTTP 401 response is returned and the user
can provide credentials with the appropriate permissions to gain
access. Defaults to `true`.

[float]
[[security-automata-settings]]
==== Automata Settings
In places where the {security-features} accept wildcard patterns (e.g. index
patterns in roles, group matches in the role mapping API), each pattern is
compiled into an Automaton. The follow settings are available to control this
behaviour.

`xpack.security.automata.max_determinized_states`::
The upper limit on how many automaton states may be created by a single pattern.
This protects against too-difficult (e.g. exponentially hard) patterns.
Defaults to `100,000`.

`xpack.security.automata.cache.enabled`::
Whether to cache the compiled automata. Compiling automata can be CPU intensive
and may slowdown some operations. The cache reduces the frequency with which
automata need to be compiled.
Defaults to `true`.

`xpack.security.automata.cache.size`::
The maximum number of items to retain in the automata cache.
Defaults to `10,000`.

`xpack.security.automata.cache.ttl`::
The length of time to retain in an item in the automata cache (based on most
recent usage).
Defaults to `48h` (48 hours).

[float]
[[field-document-security-settings]]
==== Document and field level security settings

You can set the following document and field level security
settings in `elasticsearch.yml`. For more information, see
<<field-and-document-access-control>>.

`xpack.security.dls_fls.enabled`::
Set to `false` to prevent document and field level security
from being configured. Defaults to `true`.

`xpack.security.dls.bitset.cache.ttl`::
The time-to-live for cached `BitSet` entries for document level security.
Document level security queries may depend on Lucene BitSet objects, and these are
automatically cached to improve performance. Defaults to expire entries that are
unused for `168h` (7 days).

`xpack.security.dls.bitset.cache.size`::
The maximum memory usage of cached `BitSet` entries for document level security.
Document level security queries may depend on Lucene BitSet objects, and these are
automatically cached to improve performance. Defaults to `50mb`, after which 
least-recently-used entries will be evicted.

[float]
[[token-service-settings]]
==== Token service settings

You can set the following token service settings in
`elasticsearch.yml`.

`xpack.security.authc.token.enabled`::
Set to `false` to disable the built-in token service. Defaults to `true` unless
 `xpack.security.http.ssl.enabled` is `false`. This prevents sniffing the token
  from a connection over plain http.

`xpack.security.authc.token.timeout`::
The length of time that a token is valid for. By default this value is `20m` or
20 minutes. The maximum value is 1 hour.

[float]
[[api-key-service-settings]]
==== API key service settings

You can set the following API key service settings in
`elasticsearch.yml`.

`xpack.security.authc.api_key.enabled`::
Set to `false` to disable the built-in API key service. Defaults to `true` unless
 `xpack.security.http.ssl.enabled` is `false`. This prevents sniffing the API key
  from a connection over plain http.

`xpack.security.authc.api_key.hashing.algorithm`::
Specifies the hashing algorithm that is used for securing API key credentials.
See <<password-hashing-algorithms>>. Defaults to `pbkdf2`.

`xpack.security.authc.api_key.cache.ttl`::
The time-to-live for cached API key entries. A API key id and a hash of its
API key are cached for this period of time. Specify the time period using
the standard {es} <<time-units,time units>>. Defaults to `1d`.

`xpack.security.authc.api_key.cache.max_keys`::
The maximum number of API key entries that can live in the
cache at any given time. Defaults to 10,000.

`xpack.security.authc.api_key.cache.hash_algo`:: (Expert Setting)
The hashing algorithm that is used for the
in-memory cached API key credentials. For possible values, see <<cache-hash-algo>>.
Defaults to `ssha256`.

[float]
[[realm-settings]]
==== Realm settings
You configure realm settings in the `xpack.security.authc.realms`
namespace in `elasticsearch.yml`. For example:

[source,yaml]
----------------------------------------
xpack.security.authc.realms:

    native.realm1: <1>
        order: 0
        ...

    ldap.realm2:
        order: 1
        ...

    active_directory.realm3:
        order: 2
        ...
    ...
----------------------------------------
<1> Specifies the type of realm (for example, `native`, `ldap`,
`active_directory`, `pki`, `file`, `kerberos`, `saml`) and the realm name. This
information is required.

The valid settings vary depending on the realm type. For more
information, see <<setting-up-authentication>>.

[float]
[[ref-realm-settings]]
===== Settings valid for all realms

`order`::
The priority of the realm within the realm chain. Realms with a lower order are
consulted first. Although not required, use of this setting is strongly
recommended when you configure multiple realms. Defaults to `Integer.MAX_VALUE`.

`enabled`::
Indicates whether a realm is enabled. You can use this setting to disable a
realm without removing its configuration information. Defaults to `true`.

[[ref-native-settings]]
[float]
===== Native realm settings

For a native realm, the `type` must be set to `native`. In addition to the 
<<ref-realm-settings,settings that are valid for all realms>>, you can specify  
the following optional settings: 

`cache.ttl`:: The time-to-live for cached user entries. A user and a hash of its 
credentials are cached for this period of time. Specify the time period using 
the standard {es} <<time-units,time units>>. Defaults to `20m`.

`cache.max_users`:: The maximum number of user entries that can live in the 
cache at any given time. Defaults to 100,000.

`cache.hash_algo`:: (Expert Setting) The hashing algorithm that is used for the 
in-memory cached user credentials. For possible values, see <<cache-hash-algo>>. 
Defaults to `ssha256`.

`authentication.enabled`:: If set to `false`, disables authentication support in
this realm, so that it only supports user lookups.
(See the <<run-as-privilege,run as>> and
<<authorization_realms,authorization realms>> features).
Defaults to `true`.

[[ref-users-settings]]

[float]
===== File realm settings

The `type` setting must be set to `file`. In addition to the 
<<ref-realm-settings,settings that are valid for all realms>>, you can specify  
the following settings: 

`cache.ttl`::
The time-to-live for cached user entries. A user and a hash of its credentials 
are cached for this configured period of time. Defaults to `20m`. Specify values 
using the standard {es} <<time-units,time units>>.
Defaults to `20m`.

`cache.max_users`::
The maximum number of user entries that can live in the cache at a given time.
Defaults to 100,000.

`cache.hash_algo`::
(Expert Setting) The hashing algorithm that is used for the in-memory cached
user credentials. See <<cache-hash-algo>>. Defaults to `ssha256`.

`authentication.enabled`:: If set to `false`, disables authentication support in
this realm, so that it only supports user lookups.
(See the <<run-as-privilege,run as>> and
<<authorization_realms,authorization realms>> features).
Defaults to `true`.

[[ref-ldap-settings]]
[float]
===== LDAP realm settings

The `type` setting must be set to `ldap`. In addition to the 
<<ref-realm-settings>>, you can specify the following settings: 

`url`::
One or more LDAP URLs in the `ldap[s]://<server>:<port>` format. Required.
+
To provide multiple URLs, use a YAML array (`["ldap://server1:636", "ldap://server2:636"]`)
or comma-separated string (`"ldap://server1:636, ldap://server2:636"`).
+
While both are supported, you can't mix the `ldap` and `ldaps` protocols.

`load_balance.type`::
The behavior to use when there are multiple LDAP URLs defined. For supported
values see <<load-balancing,load balancing and failover types>>.
Defaults to `failover`.

`load_balance.cache_ttl`::
When using `dns_failover` or `dns_round_robin` as the load balancing type,
this setting controls the amount of time to cache DNS lookups. Defaults
to `1h`.

`bind_dn`::
The DN of the user that is used to bind to the LDAP and perform searches.
Only applicable in user search mode.
If not specified, an anonymous bind is attempted.
Defaults to Empty. Due to its potential security impact, `bind_dn` is not 
exposed via the <<cluster-nodes-info,nodes info API>>.

`bind_password`::
deprecated[6.3] Use `secure_bind_password` instead. The password for the user 
that is used to bind to the LDAP directory.
Defaults to Empty. Due to its potential security impact, `bind_password` is not 
exposed via the <<cluster-nodes-info,nodes info API>>.


`secure_bind_password` (<<secure-settings,Secure>>)::
The password for the user that is used to bind to the LDAP directory.
Defaults to Empty.

`user_dn_templates`::
The DN template that replaces the user name with the string `{0}`.
This setting is multivalued; you can specify multiple user contexts.
Required to operate in user template mode. If `user_search.base_dn` is specified, 
this setting is not valid. For more information on
the different modes, see <<ldap-realm>>.

`authorization_realms`::
The names of the realms that should be consulted for delegated authorization.
If this setting is used, then the LDAP realm does not perform role mapping and
instead loads the user from the listed realms. The referenced realms are
consulted in the order that they are defined in this list.
See <<authorization_realms>>.
+
--
NOTE: If any settings starting with `user_search` are specified, the 
`user_dn_templates` settings are ignored.

--

`user_group_attribute`::
Specifies the attribute to examine on the user for group membership.
If any `group_search` settings are specified, this setting is ignored. Defaults 
to `memberOf`.

`user_search.base_dn`::
Specifies a container DN to search for users. Required
to operated in user search mode. If `user_dn_templates` is specified, this 
setting is not valid. For more information on
the different modes, see <<ldap-realm>>.

`user_search.scope`::
The scope of the user search. Valid values are `sub_tree`, `one_level` or
`base`. `one_level` only searches objects directly contained within the
`base_dn`. `sub_tree` searches all objects contained under `base_dn`.
`base` specifies that the `base_dn` is the user object, and that it is
the only user considered. Defaults to  `sub_tree`.

`user_search.filter`::
Specifies the filter used to search the directory in attempts to match
an entry with the username provided by the user. Defaults to `(uid={0})`.
`{0}` is substituted with the username provided when searching.

`user_search.attribute`::
deprecated[5.6] Use `user_search.filter` instead.
The attribute to match with the username sent with the request. Defaults to `uid`.

`user_search.pool.enabled`::
Enables or disables connection pooling for user search. If set to `false`, a new 
connection is created for every search. The
default is `true` when `bind_dn` is set.

`user_search.pool.size`::
The maximum number of connections to the LDAP server to allow in the
connection pool. Defaults to `20`.

`user_search.pool.initial_size`::
The initial number of connections to create to the LDAP server on startup.
Defaults to `0`. If the LDAP server is down, values greater than `0` could cause 
startup failures.

`user_search.pool.health_check.enabled`::
Enables or disables a health check on LDAP connections in the connection
pool. Connections are checked in the background at the specified interval.
Defaults to `true`.

`user_search.pool.health_check.dn`::
The distinguished name that is retrieved as part of the health check.
Defaults to the value of `bind_dn` if present; if
not, falls back to `user_search.base_dn`.

`user_search.pool.health_check.interval`::
The interval to perform background checks of connections in the pool.
Defaults to `60s`.

`group_search.base_dn`::
The container DN to search for groups in which the user has membership. When
this element is absent, {es} searches for the attribute specified by
`user_group_attribute` set on the user in order to determine group membership.

`group_search.scope`::
Specifies whether the group search should be `sub_tree`, `one_level` or
`base`.  `one_level` only searches objects directly contained within the
`base_dn`. `sub_tree` searches all objects contained under `base_dn`.
`base` specifies that the `base_dn` is a group object, and that it is the
only group considered. Defaults to  `sub_tree`.

`group_search.filter`:: 
Specifies a filter to use to look up a group. 
When not set, the realm searches for `group`, `groupOfNames`, `groupOfUniqueNames`,
or `posixGroup` with the attributes `member`, `memberOf`, or `memberUid`.  Any
instance of `{0}` in the filter is replaced by the user attribute defined in
`group_search.user_attribute`.

`group_search.user_attribute`::
Specifies the user attribute that is fetched and provided as a parameter to
the filter.  If not set, the user DN is passed into the filter. Defaults to Empty.

`unmapped_groups_as_roles`::
If set to `true`, the names of any unmapped LDAP groups are used as role names 
and assigned to the user. A group is considered to be _unmapped_ if it is not 
referenced in a <<mapping-roles-file,role-mapping file>>. API-based 
role mappings are not considered. Defaults to `false`.

`files.role_mapping`::
The <<security-files,location>> for the
<<mapping-roles,YAML role mapping configuration file>>. Defaults to
`ES_PATH_CONF/role_mapping.yml`.

`follow_referrals`::
Specifies whether {es} should follow referrals returned
by the LDAP server. Referrals are URLs returned by the server that are to be
used to continue the LDAP operation (for example, search). Defaults to `true`.

`metadata`::
A list of additional LDAP attributes that should be loaded from the
LDAP server and stored in the authenticated user's metadata field.

`timeout.tcp_connect`::
The TCP connect timeout period for establishing an LDAP connection.
An `s` at the end indicates seconds, or `ms` indicates milliseconds.
Defaults to `5s` (5 seconds ).

`timeout.tcp_read`::
The TCP read timeout period after establishing an LDAP connection.
An `s` at the end indicates seconds, or `ms` indicates milliseconds.
Defaults to `5s` (5 seconds ).

`timeout.ldap_search`::
The LDAP Server enforced timeout period for an LDAP search.
An `s` at the end indicates seconds, or `ms` indicates milliseconds.
Defaults to `5s` (5 seconds ).

`ssl.key`::
Path to a PEM encoded file containing the private key, which is used if the 
LDAP server requires client authentication. `ssl.key` and `ssl.keystore.path` 
cannot be used at the same time.

`ssl.key_passphrase`::
The passphrase that is used to decrypt the private key. This value is
optional as the key may not be encrypted.

`ssl.secure_key_passphrase` (<<secure-settings,Secure>>)::
The passphrase that is used to decrypt the private key.

`ssl.certificate`::
Path to a PEM encoded file containing the certificate (or certificate chain)
that will be presented to clients when they connect.

`ssl.certificate_authorities`::
List of paths to PEM encoded certificate files that should be trusted. 
`ssl.certificate_authorities` and `ssl.truststore.path` cannot be used at the 
same time.

`ssl.keystore.path`::
The path to the Java Keystore file that contains a private key and certificate.
`ssl.key` and `ssl.keystore.path` may not be used at the same time.

`ssl.keystore.type`::
The format of the keystore file. Should be `jks` to use the Java
Keystore format, `PKCS12` to use PKCS#12 files, or `PKCS11` to use a PKCS#11 token.
The default is `jks`.

`ssl.keystore.password`::
The password to the keystore.

`ssl.keystore.secure_password` (<<secure-settings,Secure>>)::
The password to the keystore.

`ssl.keystore.key_password`::
The password for the key in the keystore. Defaults to the keystore password.

`ssl.keystore.secure_key_password`::
The password for the key in the keystore. Defaults to the keystore password.

`ssl.truststore.path`::
The path to the Java Keystore file that contains the certificates to trust.
`ssl.certificate_authorities` and `ssl.truststore.path` cannot be used at the same time.

`ssl.truststore.password`::
The password to the truststore.

`ssl.truststore.secure_password` (<<secure-settings,Secure>>)::
The password to the truststore.

`ssl.truststore.type`::
The format of the keystore file. Should be `jks` to use the Java
Keystore format, `PKCS12` to use PKCS#12 files, or `PKCS11` to use a PKCS#11 token.
The default is `jks`.

`ssl.verification_mode`::
Indicates the type of verification when using `ldaps` to protect against man
in the middle attacks and certificate forgery. Values are `none`, `certificate`,
and `full`. Defaults to `full`.
+
See <<ssl-tls-settings,`ssl.verification_mode`>> for an explanation of these values.

`ssl.supported_protocols`::
Supported protocols for TLS/SSL (with versions). Defaults to `TLSv1.3,TLSv1.2,TLSv1.1`.

`ssl.cipher_suites`:: Specifies the cipher suites that should be supported when 
communicating with the LDAP server. 
Supported cipher suites can be found in Oracle's http://docs.oracle.com/javase/8/docs/technotes/guides/security/SunProviders.html[
Java Cryptography Architecture documentation]. See <<ssl-tls-settings,`ssl.cipher_suites`>>
for the default value.

`cache.ttl`::
Specifies the time-to-live for cached user entries. A user and a hash of its 
credentials are cached for this period of time. Use the standard {es}
<<time-units,time units>>. Defaults to  `20m`.

`cache.max_users`::
Specifies the maximum number of user entries that the cache can contain.
Defaults to `100000`.

`cache.hash_algo`::
(Expert Setting) Specifies the hashing algorithm that is used for the
in-memory cached user credentials. See <<cache-hash-algo>>. Defaults to `ssha256`.

`authentication.enabled`:: If set to `false`, disables authentication support in
this realm, so that it only supports user lookups.
(See the <<run-as-privilege,run as>> and
<<authorization_realms,authorization realms>> features).
Defaults to `true`.

[[ref-ad-settings]]
[float]
===== Active Directory realm settings

The `type` setting must be set to `active_directory`. In addition to the 
<<ref-realm-settings,settings that are valid for all realms>>, you can specify  
the following settings: 

`url`::
One or more LDAP URLs in the `ldap[s]://<server>:<port>` format. Defaults to
`ldap://<domain_name>:389`. This setting is required when connecting using
SSL/TLS or when using a custom port.
+
To provide multiple URLs, use a YAML array (`["ldap://server1:636", "ldap://server2:636"]`)
or comma-separated string (`"ldap://server1:636, ldap://server2:636"`).
+
While both are supported, you can't mix the `ldap` and `ldaps` protocols.
+
If no URL is provided, {es} uses a default of `ldap://<domain_name>:389`. This
default uses the `domain_name` setting value and assumes an unencrypted
connection to port 389. 

`load_balance.type`::
The behavior to use when there are multiple LDAP URLs defined. For supported
values see <<load-balancing,load balancing and failover types>>.
Defaults to `failover`.

`load_balance.cache_ttl`::
When using `dns_failover` or `dns_round_robin` as the load balancing type,
this setting controls the amount of time to cache DNS lookups. Defaults
to `1h`.

`domain_name`::
The domain name of Active Directory. If the `url` and the `user_search_dn`
settings are not specified, the cluster can derive those values from this 
setting. Required.

`bind_dn`::
The DN of the user that is used to bind to Active Directory and perform searches.
Defaults to Empty. Due to its potential security impact, `bind_dn` is not 
exposed via the <<cluster-nodes-info,nodes info API>>.

`bind_password`::
deprecated[6.3] Use `secure_bind_password` instead. The password for the user 
that is used to bind to Active Directory. Defaults to Empty. Due to its 
potential security impact, `bind_password` is not exposed via the 
<<cluster-nodes-info,nodes info API>>.

`secure_bind_password` (<<secure-settings,Secure>>)::
The password for the user that is used to bind to Active Directory.
Defaults to Empty.

`unmapped_groups_as_roles`::
If set to `true`, the names of any unmapped Active Directory groups are used as 
role names and assigned to the user. A group is considered _unmapped_ when it 
is not referenced in any role-mapping files. API-based role mappings are not 
considered. Defaults to `false`.

`files.role_mapping`::
The <<security-files,location>> for the YAML
role mapping configuration file. Defaults to `ES_PATH_CONF/role_mapping.yml`.

`user_search.base_dn`::
The context to search for a user. Defaults to the root
of the Active Directory domain.

`user_search.scope`::
Specifies whether the user search should be `sub_tree`, `one_level` or `base`.
`one_level` only searches users directly contained within the `base_dn`.
`sub_tree` searches all objects contained under `base_dn`. `base`
specifies that the `base_dn` is a user object, and that it is the
only user considered. Defaults to `sub_tree`.

`user_search.filter`::
Specifies a filter to use to lookup a user given a username.  The default
filter looks up `user` objects with either `sAMAccountName` or
`userPrincipalName`. If specified, this must be a valid LDAP user search filter. 
For example `(&(objectClass=user)(sAMAccountName={0}))`. For more information, 
see 
https://msdn.microsoft.com/en-us/library/aa746475(v=vs.85).aspx[Search Filter Syntax].

`user_search.upn_filter`::
Specifies a filter to use to lookup a user given a user principal name.
The default filter looks up `user` objects with
a matching `userPrincipalName`. If specified, this
must be a valid LDAP user search filter. For example,
`(&(objectClass=user)(userPrincipalName={1}))`. `{1}` is the full user principal name
provided by the user. For more information, see 
https://msdn.microsoft.com/en-us/library/aa746475(v=vs.85).aspx[Search Filter Syntax].

`user_search.down_level_filter`::
Specifies a filter to use to lookup a user given a down level logon name
(DOMAIN\user). The default filter looks up `user` objects with a matching
`sAMAccountName` in the domain provided. If specified, this
must be a valid LDAP user search filter. For example,
`(&(objectClass=user)(sAMAccountName={0}))`. For more information, see 
https://msdn.microsoft.com/en-us/library/aa746475(v=vs.85).aspx[Search Filter Syntax]. 

`user_search.pool.enabled`::
Enables or disables connection pooling for user search. When
disabled a new connection is created for every search. The
default is `true` when `bind_dn` is provided.

`user_search.pool.size`::
The maximum number of connections to the Active Directory server to allow in the
connection pool. Defaults to `20`.

`user_search.pool.initial_size`::
The initial number of connections to create to the Active Directory server on startup.
Defaults to `0`. If the LDAP server is down, values greater than 0 
could cause startup failures. 

`user_search.pool.health_check.enabled`::
Enables or disables a health check on Active Directory connections in the connection
pool. Connections are checked in the background at the specified interval.
Defaults to `true`.

`user_search.pool.health_check.dn`::
The distinguished name to be retrieved as part of the health check.
Defaults to the value of `bind_dn` if that setting is present. Otherwise, it 
defaults to the value of the `user_search.base_dn` setting. 

`user_search.pool.health_check.interval`::
The interval to perform background checks of connections in the pool.
Defaults to `60s`.

`group_search.base_dn`::
The context to search for groups in which the user has membership.  Defaults
to the root of the Active Directory domain.

`group_search.scope`::
Specifies whether the group search should be `sub_tree`, `one_level` or
`base`.  `one_level` searches for groups directly contained within the
`base_dn`. `sub_tree` searches all objects contained under `base_dn`.
`base` specifies that the `base_dn` is a group object, and that it is
the only group considered. Defaults to `sub_tree`.

`metadata`::
A list of additional LDAP attributes that should be loaded from the
LDAP server and stored in the authenticated user's metadata field.

`timeout.tcp_connect`::
The TCP connect timeout period for establishing an LDAP connection.
An `s` at the end indicates seconds, or `ms` indicates milliseconds.
Defaults to `5s` (5 seconds ).

`timeout.tcp_read`::
The TCP read timeout period after establishing an LDAP connection.
An `s` at the end indicates seconds, or `ms` indicates milliseconds.
Defaults to `5s` (5 seconds ).

`timeout.ldap_search`::
The LDAP Server enforced timeout period for an LDAP search.
An `s` at the end indicates seconds, or `ms` indicates milliseconds.
Defaults to `5s` (5 seconds ).

`ssl.certificate`::
Path to a PEM encoded file containing the certificate (or certificate chain)
that will be presented to clients when they connect. 

`ssl.certificate_authorities`::
List of paths to PEM encoded certificate files that should be trusted. 
`ssl.certificate_authorities` and `ssl.truststore.path` cannot be used at the 
same time.

`ssl.key`::
Path to the PEM encoded file containing the private key, which is used when the 
Active Directory server requires client authentication. `ssl.key` and 
`ssl.keystore.path` cannot be used at the same time.


`ssl.key_passphrase`::
The passphrase that is used to decrypt the private key. This value is
optional as the key might not be encrypted.

`ssl.secure_key_passphrase` (<<secure-settings,Secure>>)::
The passphrase that is used to decrypt the private key. This value is
optional as the key might not be encrypted.

`ssl.keystore.key_password`::
The password for the key in the keystore. Defaults to the keystore password.

`ssl.keystore.secure_key_password` (<<secure-settings,Secure>>)::
The password for the key in the keystore. Defaults to the keystore password.

`ssl.keystore.password`::
The password to the keystore.

`ssl.secure_keystore.password` (<<secure-settings,Secure>>)::
The password to the keystore.

`ssl.keystore.path`::
The path to the Java Keystore file that contains a private key and certificate.
`ssl.key` and `ssl.keystore.path` cannot be used at the same time.

`ssl.keystore.type`::
The format of the keystore file. Should be `jks` to use the Java
Keystore format, `PKCS12` to use PKCS#12 files, or `PKCS11` to use a PKCS#11 token.
The default is `jks`.

`ssl.truststore.password`::
The password to the truststore.

`ssl.truststore.secure_password` (<<secure-settings,Secure>>)::
The password to the truststore.

`ssl.truststore.path`::
The path to the Java Keystore file that contains the certificates to trust.
`ssl.certificate_authorities` and `ssl.truststore.path` cannot be used at the 
same time.

`ssl.truststore.type`::
The format of the truststore file. Should be `jks` to use the Java
Keystore format, `PKCS12` to use PKCS#12 files, or `PKCS11` to use a PKCS#11 token.
The default is `jks`.

`ssl.verification_mode`::
Indicates the type of verification when using `ldaps` to protect against man
in the middle attacks and certificate forgery. Values are `none`, `certificate`,
and `full`. Defaults to `full`.
+
See <<ssl-tls-settings,`ssl.verification_mode`>> for an explanation of these values.

`ssl.supported_protocols`::
Supported protocols for TLS/SSL (with versions). Defaults to `TLSv1.3,TLSv1.2,TLSv1.1`.

`ssl.cipher_suites`:: Specifies the cipher suites that should be supported when 
communicating with the Active Directory server. 
Supported cipher suites can be found in Oracle's http://docs.oracle.com/javase/8/docs/technotes/guides/security/SunProviders.html[
Java Cryptography Architecture documentation]. See <<ssl-tls-settings,`ssl.cipher_suites`>> for
the default values.

`cache.ttl`::
Specifies the time-to-live for cached user entries. A user and a hash of its 
credentials are cached for this configured period of time. Use the
standard Elasticsearch <<time-units,time units>>).
Defaults to `20m`.

`cache.max_users`::
Specifies the maximum number of user entries that the cache can contain.
Defaults to `100000`.

`cache.hash_algo`::
(Expert Setting) Specifies the hashing algorithm that is used for
the in-memory cached user credentials. See <<cache-hash-algo>>. Defaults to `ssha256`.

`authentication.enabled`:: If set to `false`, disables authentication support in
this realm, so that it only supports user lookups.
(See the <<run-as-privilege,run as>> and
<<authorization_realms,authorization realms>> features).
Defaults to `true`.

`follow_referrals`::
If set to `true`, {es} follows referrals returned by the LDAP server. 
Referrals are URLs returned by the server that are to be used to continue the 
LDAP operation (such as `search`). Defaults to `true`.

[[ref-pki-settings]]
[float]
===== PKI realm settings

The `type` setting must be set to `pki`. In addition to the 
<<ref-realm-settings,settings that are valid for all realms>>, you can specify  
the following settings: 

`username_pattern`::
The regular expression pattern used to extract the username from the
certificate DN. The first match group is the used as the username.
Defaults to `CN=(.*?)(?:,\|$)`.

`certificate_authorities`::
List of paths to the PEM certificate files that should be used to authenticate a
user's certificate as trusted. Defaults to the trusted certificates configured
for SSL. This setting cannot be used with `truststore.path`. 

`truststore.algorithm`::
Algorithm for the truststore. Defaults to `SunX509`.

`truststore.password`::
The password for the truststore. Must be provided if `truststore.path` is set.

`truststore.secure_password` (<<secure-settings,Secure>>)::
The password for the truststore.

`truststore.path`::
The path of a truststore to use. Defaults to the trusted certificates configured
for SSL. This setting cannot be used with `certificate_authorities`.

`files.role_mapping`::
Specifies the <<security-files,location>> of the
<<mapping-roles,YAML role  mapping configuration file>>.
Defaults to `ES_PATH_CONF/role_mapping.yml`.

`authorization_realms`::
The names of the realms that should be consulted for delegated authorization.
If this setting is used, then the PKI realm does not perform role mapping and
instead loads the user from the listed realms.
See <<authorization_realms>>. 

`cache.ttl`::
Specifies the time-to-live for cached user entries. A user and a hash of its 
credentials are cached for this period of time. Use the
standard {es} <<time-units,time units>>).
Defaults to `20m`.

`cache.max_users`::
Specifies the maximum number of user entries that the cache can contain.
Defaults to `100000`.

`delegation.enabled`::
Generally, in order for the clients to be authenticated by the PKI realm they
must connect directly to {es}. That is, they must not pass through proxies
which terminate the TLS connection. In order to allow for a *trusted* and
*smart* proxy, such as Kibana, to sit before {es} and terminate TLS
connections, but still allow clients to be authenticated on {es} by this realm,
you need to toggle this to `true`. Defaults to `false`. If delegation is
enabled, then either `truststore.path` or `certificate_authorities` setting
must be defined. For more details, see <<pki-realm-for-proxied-clients,
Configuring authentication delegation for PKI realms>>.

[[ref-saml-settings]]
[float]
===== SAML realm settings

The `type` setting must be set to `saml`. In addition to the 
<<ref-realm-settings,settings that are valid for all realms>>, you can specify  
the following settings: 

`idp.entity_id`::
The Entity ID of the SAML Identity Provider. An Entity ID is a URI with a 
maximum length of 1024 characters. It can be a URL (https://idp.example.com/) or 
a URN (`urn:example.com:idp`) and can be found in the configuration or the SAML 
metadata of the Identity Provider.

`idp.metadata.path`::
The path _(recommended)_ or URL to a SAML 2.0 metadata file describing the
capabilities and configuration of the Identity Provider.
If a path is provided, then it is resolved relative to the {es} config
directory.
If a URL is provided, then it must be either a `file` URL or a `https` URL.
{es} automatically polls this metadata resource and reloads 
the IdP configuration when changes are detected.
File based resources are polled at a frequency determined by the global {es}
`resource.reload.interval.high` setting, which defaults to 5 seconds.
HTTPS resources are polled at a frequency determined by the realm's
`idp.metadata.http.refresh` setting.

`idp.metadata.http.refresh`::
Controls the frequency with which `https` metadata is checked for changes.
Defaults to `1h` (1 hour).

`idp.use_single_logout`::
Indicates whether to utilise the Identity Provider's Single Logout service
(if one exists in the IdP metadata file).
Defaults to `true`.

`sp.entity_id`::
The Entity ID to use for this SAML Service Provider. This should be entered as a 
URI. We recommend that you use the base URL of your Kibana instance. For example, 
`https://kibana.example.com/`. 

`sp.acs`::
The URL of the Assertion Consumer Service within {kib}. Typically this is the 
"api/security/saml/callback" endpoint of your Kibana server. For example,
`https://kibana.example.com/api/security/saml/callback`.

`sp.logout`::
The URL of the Single Logout service within {kib}. Typically this is the 
"logout" endpoint of your Kibana server. For example, 
`https://kibana.example.com/logout`.

`attributes.principal`::
The Name of the SAML attribute that contains the user's principal (username).

`attributes.groups`::
The Name of the SAML attribute that contains the user's groups. 

`attributes.name`::
The Name of the SAML attribute that contains the user's full name. 

`attributes.mail`::
The Name of the SAML attribute that contains the user's email address. 

`attributes.dn`::
The Name of the SAML attribute that contains the user's X.50
_Distinguished Name_. 

`attribute_patterns.principal`::
A Java regular expression that is matched against the SAML attribute specified
by `attributes.pattern` before it is applied to the user's _principal_ property.
The attribute value must match the pattern and the value of the first
_capturing group_ is used as the principal. For example, `^([^@]+)@example\\.com$` 
matches email addresses from the "example.com" domain and uses the local-part as 
the principal.

`attribute_patterns.groups`::
As per `attribute_patterns.principal`, but for the _group_ property.

`attribute_patterns.name`::
As per `attribute_patterns.principal`, but for the _name_ property.

`attribute_patterns.mail`::
As per `attribute_patterns.principal`, but for the _mail_ property.

`attribute_patterns.dn`::
As per `attribute_patterns.principal`, but for the _dn_ property.

`nameid_format`::
The NameID format that should be requested when asking the IdP to authenticate
the current user. The default is to not  include the `nameid_format` attribute.

`nameid.allow_create`:: The value of the `AllowCreate` attribute of the 
`NameIdPolicy` element in an authentication request. The default value is false.

`nameid.sp_qualifier`:: The value of the `SPNameQualifier` attribute of the 
`NameIdPolicy` element in an authentication request. The default is to not 
include the `SPNameQualifier` attribute.

`force_authn`::
Specifies whether to set the `ForceAuthn` attribute when requesting that the IdP
authenticate the current user. If set to `true`, the IdP is required to verify 
the user’s identity, irrespective of any existing sessions they might have. 
Defaults to `false`.

`populate_user_metadata`::
Specifies whether to populate the {es} user's metadata with the values that are 
provided by the SAML attributes. Defaults to `true`.

`authorization_realms`::
The names of the realms that should be consulted for delegated authorization.
If this setting is used, then the SAML realm does not perform role mapping and
instead loads the user from the listed realms.
See <<authorization_realms>>.

`allowed_clock_skew`::
The maximum amount of skew that can be tolerated between the IdP's clock and the
{es} node's clock.
Defaults to `3m` (3 minutes).

`req_authn_context_class_ref`::
A comma separated list of Authentication Context Class Reference values to be
included in the Requested Authentication Context when requesting the IdP to
authenticate the current user. The Authentication Context of the corresponding
authentication response should contain at least one of the requested values.
+
For more information, see
<<req-authn-context>>.

[float]
[[ref-saml-signing-settings]]
===== SAML realm signing settings

If a signing key is configured (that is, either `signing.key` or 
`signing.keystore.path` is set), then {es} signs outgoing SAML messages. 
Signing can be configured using the following settings:

`signing.saml_messages`::
A list of SAML message types that should be signed or `*` to sign all messages.
Each element in the list should be the local name of a SAML XML Element.
Supported element types are `AuthnRequest`, `LogoutRequest` and `LogoutResponse`.
Only valid if `signing.key` or `signing.keystore.path` is also specified.
Defaults to `*`.

`signing.key`::
Specifies the path to the PEM encoded private key to use for SAML message signing.
`signing.key` and `signing.keystore.path` cannot be used at the same time.

`signing.secure_key_passphrase` (<<secure-settings,Secure>>)::
Specifies the passphrase to decrypt the PEM encoded private key (`signing.key`)
if it is encrypted.

`signing.certificate`::
Specifies the path to the PEM encoded certificate (or certificate chain) that 
corresponds to the `signing.key`. This certificate must also be included in the 
Service Provider metadata or manually configured within the IdP to allow for 
signature validation. This setting can only be used if `signing.key` is set.

`signing.keystore.path`::
The path to the keystore that contains a private key and certificate.
Must be either a Java Keystore (jks) or a PKCS#12 file.
`signing.key` and `signing.keystore.path` cannot be used at the same time.

`signing.keystore.type`::
The type of the keystore in `signing.keystore.path`.
Must be either `jks` or `PKCS12`. If the keystore path ends in ".p12", ".pfx", 
or "pkcs12", this setting defaults to `PKCS12`. Otherwise, it defaults to `jks`.

`signing.keystore.alias`::
Specifies the alias of the key within the keystore that should be
used for SAML message signing. If the keystore contains more than one private 
key, this setting must be specified. 

`signing.keystore.secure_password` (<<secure-settings,Secure>>)::
The password to the keystore in `signing.keystore.path`.

`signing.keystore.secure_key_password` (<<secure-settings,Secure>>)::
The password for the key in the keystore (`signing.keystore.path`).
Defaults to the keystore password.

[float]
[[ref-saml-encryption-settings]]
===== SAML realm encryption settings

If an encryption key is configured (that is, either `encryption.key` or 
`encryption.keystore.path` is set), then {es} publishes an encryption 
certificate when generating metadata and attempts to decrypt incoming SAML 
content. Encryption can be configured using the following settings:

`encryption.key`::
Specifies the path to the PEM encoded private key to use for SAML message
decryption.
`encryption.key` and `encryption.keystore.path` cannot be used at the same time.

`encryption.secure_key_passphrase` (<<secure-settings,Secure>>)::
Specifies the passphrase to decrypt the PEM encoded private key
(`encryption.key`) if it is encrypted.

`encryption.certificate`::
Specifies the path to the PEM encoded certificate (or certificate chain) that is 
associated with the `encryption.key`. This certificate must also be included in 
the Service Provider metadata or manually configured within the IdP to enable 
message encryption. This setting can be used only if `encryption.key` is set.

`encryption.keystore.path`::
The path to the keystore that contains a private key and certificate.
Must be either a Java Keystore (jks) or a PKCS#12 file.
`encryption.key` and `encryption.keystore.path` cannot be used at the same time.

`encryption.keystore.type`::
The type of the keystore (`encryption.keystore.path`).
Must be either `jks` or `PKCS12`. If the keystore path ends in ".p12", ".pfx", 
or "pkcs12", this setting defaults to `PKCS12`. Otherwise, it defaults to `jks`.

`encryption.keystore.alias`::
Specifies the alias of the key within the keystore (`encryption.keystore.path`)
that should be used for SAML message decryption. If not specified, all compatible
key pairs from the keystore are considered as candidate keys for decryption.

`encryption.keystore.secure_password` (<<secure-settings,Secure>>)::
The password to the keystore (`encryption.keystore.path`).

`encryption.keystore.secure_key_password` (<<secure-settings,Secure>>)::
The password for the key in the keystore (`encryption.keystore.path`). Only a
single password is supported. If you are using multiple decryption keys, 
they cannot have individual passwords.

[float]
[[ref-saml-ssl-settings]]
===== SAML realm SSL settings

If you are loading the IdP metadata over SSL/TLS (that is, `idp.metadata.path` 
is a URL using the `https` protocol), the following settings can be used to 
configure SSL.

NOTE: These settings are not used for any purpose other than loading metadata 
over https.

`ssl.key`::
Specifies the path to the PEM encoded private key to use for http client 
authentication (if required). `ssl.key` and `ssl.keystore.path` cannot be used 
at the same time.

`ssl.key_passphrase`::
Specifies the
passphrase to decrypt the PEM encoded private key (`ssl.key`) if it is
encrypted. Cannot be used with `ssl.secure_key_passphrase`. 

`ssl.secure_key_passphrase` (<<secure-settings,Secure>>)::
Specifies the
passphrase to decrypt the PEM encoded private key (`ssl.key`) if it is
encrypted. Cannot be used with `ssl.key_passphrase`. 

`ssl.certificate`::
Specifies the
path to the PEM encoded certificate (or certificate chain) that is associated
with the key (`ssl.key`). This setting can be used only if `ssl.key` is set.

`ssl.certificate_authorities`::
Specifies the
paths to the PEM encoded certificate authority certificates that should be
trusted. `ssl.certificate_authorities` and `ssl.truststore.path` cannot be
used at the same time.

`ssl.keystore.path`::
Specifies the path to
the keystore that contains a private key and certificate.
Must be either a Java Keystore (jks) or a PKCS#12 file.
`ssl.key` and `ssl.keystore.path` cannot be used at the same time.

`ssl.keystore.type`::
The type of the keystore (`ssl.keystore.path`). Must be either `jks` or `PKCS12`.
If the keystore path ends in ".p12", ".pfx" or "pkcs12", this setting defaults 
to `PKCS12`. Otherwise, it defaults to `jks`.

`ssl.keystore.password`::
The password to the keystore (`ssl.keystore.path`). This setting cannot be used 
with `ssl.keystore.secure_password`.

`ssl.keystore.secure_password` (<<secure-settings,Secure>>)::
The password to the keystore (`ssl.keystore.path`).
This setting cannot be used with `ssl.keystore.password`.

`ssl.keystore.key_password`::
The password for the key in the keystore (`ssl.keystore.path`).
Defaults to the keystore password. This setting cannot be used with 
`ssl.keystore.secure_key_password`.

`ssl.keystore.secure_key_password` (<<secure-settings,Secure>>)::
The password for the key in the keystore (`ssl.keystore.path`).
Defaults to the keystore password. This setting cannot be used with 
`ssl.keystore.key_password`.

`ssl.truststore.path`::
The path to the
keystore that contains the certificates to trust.
Must be either a Java Keystore (jks) or a PKCS#12 file.
`ssl.certificate_authorities` and `ssl.truststore.path` cannot be used at the
same time.

`ssl.truststore.type`::
The type of the truststore (`ssl.truststore.path`). Must be either `jks` or
`PKCS12`. If the keystore path ends in ".p12", ".pfx" or "pkcs12", this setting 
defaults to `PKCS12`. Otherwise, it defaults to `jks`.

`ssl.truststore.password`::
The password to the truststore (`ssl.truststore.path`). This setting cannot be 
used with `ssl.truststore.secure_password`.

`ssl.truststore.secure_password` (<<secure-settings,Secure>>)::
The password to the truststore (`ssl.truststore.path`). This setting cannot be 
used with `ssl.truststore.password`.

`ssl.verification_mode`::
One of `full`
(verify the hostname and the certificate path), `certificate` (verify the
certificate path, but not the hostname) or `none` (perform no verification).
Defaults to `full`.
+
See <<ssl-tls-settings,`ssl.verification_mode`>> for a more detailed explanation of these values.

`ssl.supported_protocols`::
Specifies the supported protocols for TLS/SSL. Defaults to `TLSv1.3,TLSv1.2,TLSv1.1`.

`ssl.cipher_suites`::
Specifies the
cipher suites that should be supported.

[float]
[[ref-kerberos-settings]]
===== Kerberos realm settings

For a Kerberos realm, the `type` must be set to `kerberos`. In addition to the
<<ref-realm-settings,settings that are valid for all realms>>, you can specify
the following settings:

`keytab.path`:: Specifies the path to the Kerberos keytab file that contains the 
service principal used by this {es} node. This must be a location within the
{es} configuration directory and the file must have read permissions. Required.

`remove_realm_name`:: Set to `true` to remove the realm part of principal names. 
Principal names in Kerberos have the form `user/instance@REALM`. If this option 
is `true`, the realm part (`@REALM`) will not be included in the username.
Defaults to `false`.

`krb.debug`:: Set to `true` to enable debug logs for the Java login module that
provides support for Kerberos authentication. Defaults to `false`.

`cache.ttl`:: The time-to-live for cached user entries. A user is cached for
this period of time. Specify the time period using the standard {es}
<<time-units,time units>>. Defaults to `20m`.

`cache.max_users`:: The maximum number of user entries that can live in the
cache at any given time. Defaults to 100,000.

`authorization_realms`::
The names of the realms that should be consulted for delegated authorization.
If this setting is used, then the Kerberos realm does not perform role mapping and
instead loads the user from the listed realms.
See <<authorization_realms>>.

[[ref-oidc-settings]]
[float]
===== OpenID Connect realm settings

In addition to the <<ref-realm-settings,settings that are valid for all realms>>, you
can specify the following settings:

`op.issuer`::
A verifiable Identifier for your OpenID Connect Provider. An Issuer
Identifier is usually a case sensitive URL using the https scheme that contains
scheme, host, and optionally, port number and path components and no query or
fragment components. The value for this setting should be provided by your OpenID
Connect Provider.

`op.authorization_endpoint`::
The URL for the Authorization Endpoint at the
OpenID Connect Provider. The value for this setting should be provided by your OpenID
Connect Provider.

`op.token_endpoint`::
The URL for the Token Endpoint at the OpenID Connect Provider.
The value for this setting should be provided by your OpenID Connect Provider.

`op.userinfo_endpoint`::
The URL for the User Info Endpoint at the OpenID Connect Provider.
The value for this setting should be provided by your OpenID Connect Provider.

`op.endsession_endpoint`::
The URL for the End Session Endpoint at the OpenID Connect
Provider. The value for this setting should be provided by your OpenID Connect Provider.

`op.jwkset_path`::
The path or URL to a JSON Web Key Set with the key material that the OpenID Connect
Provider uses for signing tokens and claims responses.
If a path is provided, then it is resolved relative to the {es} config
directory.
If a URL is provided, then it must be either a `file` URL or a `https` URL.
{es} automatically caches the retrieved JWK set to avoid unnecessary HTTP
requests but will attempt to refresh the JWK upon signature verification
failure, as this might indicate that the OpenID Connect Provider has
rotated the signing keys.

File based resources are polled at a frequency determined by the global {es}
`resource.reload.interval.high` setting, which defaults to 5 seconds.

`rp.client_id`::
The OAuth 2.0 Client Identifier that was assigned to {es} during registration
at the OpenID Connect Provider

`rp.client_secret`(<<secure-settings,Secure>>)::
The OAuth 2.0 Client Secret that was assigned to {es} during registration
at the OpenID Connect Provider

`rp.redirect_uri`::
The Redirect URI within {kib}. If you want to use the authorization code flow, this is the
"api/security/v1/oidc" endpoint of your {kib} server. If you want to use the implicit flow,  it is the "api/security/v1/oidc/implicit" endpoint.
For example, `https://kibana.example.com/api/security/v1/oidc`.

`rp.response_type`::
OAuth 2.0 Response Type value that determines the authorization
processing flow to be used. Can be `code` for authorization code grant flow,
or one of `id_token`, `id_token token` for the implicit flow.

`rp.signature_algorithm`::
The signature algorithm that will be used by {es} in order to verify the
signature of the id tokens it will receive from the OpenID Connect Provider.
Defaults to `RSA256`

`rp.requested_scopes`::
The scope values that will be requested by the OpenID Connect Provider as
part of the Authentication Request. Optional, defaults to `openid`

`rp.post_logout_redirect_uri`::
The Redirect URI (usually within {kib}) that the OpenID Connect Provider
should redirect the browser to after a successful Single Logout.

`claims.principal`::
The name of the OpenID Connect claim that contains the user's principal (username).

`claims.groups`::
The name of the OpenID Connect claim that contains the user's groups.

`claims.name`::
The name of the OpenID Connect claim that contains the user's full name.

`claims.mail`::
The name of the OpenID Connect claim that contains the user's email address.

`claims.dn`::
The name of the OpenID Connect claim that contains the user's X.509
_Distinguished Name_.

`claim_patterns.principal`::
A Java regular expression that is matched against the OpenID Connect claim specified
by `claims.principal` before it is applied to the user's _principal_ property.
The attribute value must match the pattern and the value of the first
_capturing group_ is used as the principal. For example, `^([^@]+)@example\\.com$`
matches email addresses from the "example.com" domain and uses the local-part as
the principal.

`claim_patterns.groups`::
As per `claim_patterns.principal`, but for the _group_ property.

`claim_patterns.name`::
As per `claim_patterns.principal`, but for the _name_ property.

`claim_patterns.mail`::
As per `claim_patterns.principal`, but for the _mail_ property.

`claim_patterns.dn`::
As per `claim_patterns.principal`, but for the _dn_ property.


`allowed_clock_skew`::
The maximum allowed clock skew to be taken into consideration when validating
id tokens with regards to their creation and expiration times.

`populate_user_metadata`::
Specifies whether to populate the {es} user's metadata with the values that are
provided by the OpenID Connect claims. Defaults to `true`.

`http.connect_timeout`::
Controls the behavior of the http client used for back-channel communication to
the OpenID Connect Provider endpoints. Specifies the timeout until a connection
 is established. A value of zero means the timeout is not used. Defaults to `5s`

`http.connection_read_timeout`::
Controls the behavior of the http client used for back-channel communication to
the OpenID Connect Provider endpoints. Specifies the timeout used when
requesting a connection from the connection manager. Defaults to `5s`

`http.socket_timeout`::
Controls the behavior of the http client used for back-channel communication to
the OpenID Connect Provider endpoints. Specifies the socket timeout (SO_TIMEOUT)
in milliseconds, which is the timeout for waiting for data or, put differently,
a maximum period inactivity between two consecutive data packets). Defaults to
`5s`

`http.max_connections`::
Controls the behavior of the http client used for back-channel communication to
the OpenID Connect Provider endpoints. Specifies the maximum number of
connections allowed across all endpoints.

`http.max_endpoint_connections`::
Controls the behavior of the http client used for back-channel communication to
the OpenID Connect Provider endpoints. Specifies the maximum number of
connections allowed per endpoint.

[float]
[[ref-oidc-ssl-settings]]
===== OpenID Connect realm SSL settings

The following settings can be used to configure SSL for all outgoing http connections
to the OpenID Connect Provider endpoints.

NOTE: These settings are _only_ used for the back-channel communication between
{es} and the OpenID Connect Provider

`ssl.key`::
Specifies the path to the PEM encoded private key to use for http client
authentication (if required). `ssl.key` and `ssl.keystore.path` cannot be used
at the same time.

`ssl.key_passphrase`::
Specifies the passphrase to decrypt the PEM encoded private key (`ssl.key`) if it is
encrypted. Cannot be used with `ssl.secure_key_passphrase`.

`ssl.secure_key_passphrase` (<<secure-settings,Secure>>)::
Specifies the passphrase to decrypt the PEM encoded private key (`ssl.key`) if it is
encrypted. Cannot be used with `ssl.key_passphrase`.

`ssl.certificate`::
Specifies the path to the PEM encoded certificate (or certificate chain) that is associated
with the key (`ssl.key`). This setting can be used only if `ssl.key` is set.

`ssl.certificate_authorities`::
Specifies the paths to the PEM encoded certificate authority certificates that should be
trusted. `ssl.certificate_authorities` and `ssl.truststore.path` cannot be
used at the same time.

`ssl.keystore.path`::
Specifies the path to the keystore that contains a private key and certificate.
Must be either a Java Keystore (jks) or a PKCS#12 file.
`ssl.key` and `ssl.keystore.path` cannot be used at the same time.

`ssl.keystore.type`::
The type of the keystore (`ssl.keystore.path`). Must be either `jks` or `PKCS12`.
If the keystore path ends in ".p12", ".pfx" or "pkcs12", this setting defaults
to `PKCS12`. Otherwise, it defaults to `jks`.

`ssl.keystore.password`::
The password to the keystore (`ssl.keystore.path`). This setting cannot be used
with `ssl.keystore.secure_password`.

`ssl.keystore.secure_password` (<<secure-settings,Secure>>)::
The password to the keystore (`ssl.keystore.path`).
This setting cannot be used with `ssl.keystore.password`.

`ssl.keystore.key_password`::
The password for the key in the keystore (`ssl.keystore.path`).
Defaults to the keystore password. This setting cannot be used with
`ssl.keystore.secure_key_password`.

`ssl.keystore.secure_key_password` (<<secure-settings,Secure>>)::
The password for the key in the keystore (`ssl.keystore.path`).
Defaults to the keystore password. This setting cannot be used with
`ssl.keystore.key_password`.

`ssl.truststore.path`::
The path to the keystore that contains the certificates to trust.
Must be either a Java Keystore (jks) or a PKCS#12 file.
`ssl.certificate_authorities` and `ssl.truststore.path` cannot be used at the
same time.

`ssl.truststore.type`::
The type of the truststore (`ssl.truststore.path`). Must be either `jks` or
`PKCS12`. If the keystore path ends in ".p12", ".pfx" or "pkcs12", this setting
defaults to `PKCS12`. Otherwise, it defaults to `jks`.

`ssl.truststore.password`::
The password to the truststore (`ssl.truststore.path`). This setting cannot be
used with `ssl.truststore.secure_password`.

`ssl.truststore.secure_password` (<<secure-settings,Secure>>)::
The password to the truststore (`ssl.truststore.path`). This setting cannot be
used with `ssl.truststore.password`.

`ssl.verification_mode`::
One of `full` (verify the hostname and the certificate path), `certificate` (verify the
certificate path, but not the hostname) or `none` (perform no verification).
Defaults to `full`.
+
See <<ssl-tls-settings,`ssl.verification_mode`>> for a more detailed explanation of these values.

`ssl.supported_protocols`::
Specifies the supported protocols for TLS/SSL. Defaults to `TLSv1.3,TLSv1.2,TLSv1.1` if
the JVM supports TLSv1.3, otherwise `TLSv1.2,TLSv1.1`.

`ssl.cipher_suites`::
Specifies the cipher suites that should be supported.

[float]
[[load-balancing]]
===== Load balancing and failover

The `load_balance.type` setting can have the following values: 

* `failover`: The URLs specified are used in the order that they are specified. 
The first server that can be connected to will be used for all subsequent 
connections. If a connection to that server fails then the next server that a 
connection can be established to will be used for subsequent connections.
* `dns_failover`: In this mode of operation, only a single URL may be specified.
This URL must contain a DNS name. The system will be queried for all IP 
addresses that correspond to this DNS name. Connections to the Active Directory 
or LDAP server will always be tried in the order in which they were retrieved. 
This differs from `failover` in that there is no reordering of the list and if a 
server has failed at the beginning of the list, it will still be tried for each 
subsequent connection.
* `round_robin`: Connections will continuously iterate through the list of 
provided URLs. If a server is unavailable, iterating through the list of URLs 
will continue until a successful connection is made.
* `dns_round_robin`: In this mode of operation, only a single URL may be 
specified. This URL must contain a DNS name. The system will be queried for all 
IP addresses that correspond to this DNS name. Connections will continuously 
iterate through the list of addresses. If a server is unavailable, iterating 
through the list of URLs will continue until a successful connection is made.

[float]
[[ssl-tls-settings]]
==== General TLS settings
`xpack.security.ssl.diagnose.trust`::
Controls whether to output diagnostic messages for SSL/TLS trust failures.
If this is `true` (the default), a message will be printed to the Elasticsearch
log whenever an SSL connection (incoming or outgoing) is rejected due to a failure
to establish trust.
This diagnostic message contains information that can be used to determine the
cause of the failure and assist with resolving the problem.
Set to `false` to disable these messages.

==== Default values for TLS/SSL settings
In general, the values below represent the default values for the various TLS
settings.
The prefixes for these settings are based on the context in which they are
used (e.g. `xpack.security.authc.realms.ldap.corp_ldap.ssl.verification_mode`
or `xpack.security.transport.ssl.supported_protocols`).

For more information, see
<<encrypting-communications>>.

`*.ssl.supported_protocols`::
Supported protocols with versions. Valid protocols: `SSLv2Hello`,
`SSLv3`, `TLSv1`, `TLSv1.1`, `TLSv1.2`, `TLSv1.3`. Defaults to `TLSv1.3,TLSv1.2,TLSv1.1`.
+
--
NOTE: If `xpack.security.fips_mode.enabled` is `true`, you cannot use `SSLv2Hello` 
or `SSLv3`. See <<fips-140-compliance>>.
--

`*.ssl.client_authentication`::
Controls the server's behavior in regard to requesting a certificate
from client connections. Valid values are `required`, `optional`, and `none`.
`required` forces a client to present a certificate, while `optional`
requests a client certificate but the client is not required to present one.
Defaults to `required`, except for HTTP, which defaults to `none`. See
 <<http-tls-ssl-settings>>.

`*.ssl.verification_mode`::
Controls the verification of certificates. Valid values are:
- `full`, which verifies that the provided certificate is signed by a trusted
       authority (CA) and also verifies that the server's hostname (or IP
       address) matches the names identified within the certificate.
- `certificate`, which verifies that the provided certificate is signed by a
       trusted authority (CA), but does not perform any hostname verification.
- `none`, which performs _no verification_ of the server's certificate. This mode
       disables many of the security benefits of SSL/TLS and should only be
       used after very careful consideration. It is primarily intended as a
       temporary diagnostic mechanism when attempting to resolve TLS errors,
       and its use on production clusters is strongly discouraged.
+
The default value is `full`.

`*.ssl.cipher_suites`::
Supported cipher suites can be found in Oracle's
https://docs.oracle.com/en/java/javase/11/security/oracle-providers.html#GUID-7093246A-31A3-4304-AC5F-5FB6400405E2[Java Cryptography Architecture documentation].
Defaults to `TLS_AES_256_GCM_SHA384`, `TLS_AES_128_GCM_SHA256`,
`TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384`, `TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256`,
`TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384`, `TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256`,
`TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384`, `TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256`,
`TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384`, `TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256`,
`TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA`, `TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA`,
`TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA`, `TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA`,
`TLS_RSA_WITH_AES_256_GCM_SHA384`, `TLS_RSA_WITH_AES_128_GCM_SHA256`,
`TLS_RSA_WITH_AES_256_CBC_SHA256`, `TLS_RSA_WITH_AES_128_CBC_SHA256`,
`TLS_RSA_WITH_AES_256_CBC_SHA`, `TLS_RSA_WITH_AES_128_CBC_SHA`.

[float]
[[tls-ssl-key-settings]]
===== TLS/SSL key and trusted certificate settings

The following settings are used to specify a private key, certificate, and the
trusted certificates that should be used when communicating over an SSL/TLS
connection. If no trusted certificates are configured, the default certificates
that are trusted by the JVM will be trusted along with the certificate(s)
associated with a key in the same context. The key and certificate must be in
place for connections that require client authentication or when acting as a
SSL enabled server.

[[pkcs12-truststore-note]]
[NOTE]
Storing trusted certificates in a PKCS#12 file, although supported, is
uncommon in practice. The <<certutil,`elasticsearch-certutil` tool>>,
as well as Java's `keytool`, are designed to generate PKCS#12 files that
can be used both as a keystore and as a truststore, but this may not be the
case for container files that are created using other tools. Usually,
PKCS#12 files only contain secret and private entries. To confirm that
a PKCS#12 container includes trusted certificate ("anchor") entries look for
`2.16.840.1.113894.746875.1.1: <Unsupported tag 6>` in the
`openssl pkcs12 -info` output, or `trustedCertEntry` in the
`keytool -list` output.

[[http-tls-ssl-settings]]
:ssl-prefix:             xpack.security.http
:component:              HTTP
:client-auth-default:    none
:verifies!:
:server:
:ssl-context:            security-http

include::ssl-settings.asciidoc[]

[[transport-tls-ssl-settings]]
:ssl-prefix:             xpack.security.transport
:component:              Transport
:client-auth-default!:
:verifies:
:server:
:ssl-context:            security-transport

include::ssl-settings.asciidoc[]

[[ssl-tls-profile-settings]]
[float]
===== Transport profile TLS/SSL settings
The same settings that are available for the <<transport-tls-ssl-settings, default transport>>
are also available for each transport profile. By default, the settings for a
transport profile will be the same as the default transport unless they
are specified.

As an example, lets look at the key setting. For the default transport
this is `xpack.security.transport.ssl.key`. In order to use this setting in a
transport profile, use the prefix `transport.profiles.$PROFILE.xpack.security.` and
append the portion of the setting after `xpack.security.transport.`. For the key
setting, this would be `transport.profiles.$PROFILE.xpack.security.ssl.key`.

[float]
[[ip-filtering-settings]]
==== IP filtering settings
You can configure the following settings for <<ip-filtering,IP filtering>>.

`xpack.security.transport.filter.allow`::
List of IP addresses to allow.

`xpack.security.transport.filter.deny`::
List of IP addresses to deny.

`xpack.security.http.filter.allow`::
List of IP addresses to allow just for HTTP.

`xpack.security.http.filter.deny`::
List of IP addresses to deny just for HTTP.

`transport.profiles.$PROFILE.xpack.security.filter.allow`::
List of IP addresses to allow for this profile.

`transport.profiles.$PROFILE.xpack.security.filter.deny`::
List of IP addresses to deny for this profile.

include::security-hash-settings.asciidoc[]