Back up a cluster’s security configuration
editBack up a cluster’s security configuration
editSecurity configuration information resides in two places: files and indices.
Back up file-based security configuration
editElasticsearch security features are configured using the xpack.security
namespace inside the elasticsearch.yml
and
elasticsearch.keystore
files. In addition there are several other
extra configuration files inside the same ES_PATH_CONF
directory. These files define roles and role mappings and
configure the file realm. Some of the
settings specify file paths to security-sensitive data, such as TLS keys and
certificates for the HTTP client and inter-node communication and private key files for
SAML, OIDC and the
Kerberos realms. All these are also stored inside
ES_PATH_CONF
; the path settings are relative.
The elasticsearch.keystore
, TLS keys and SAML, OIDC, and Kerberos
realms private key files require confidentiality. This is crucial when files
are copied to the backup location, as this increases the surface for malicious
snooping.
To back up all this configuration you can use a conventional file-based backup, as described in the previous section.
- File backups must run on every cluster node.
- File backups will store non-security configuration as well. Backing-up only security features configuration is not supported. A backup is a point in time record of state of the complete configuration.
Back up index-based security configuration
editElasticsearch security features store system configuration data inside a
dedicated index. This index is named .security-6
in the Elasticsearch 6.x versions and
.security-7
in the 7.x releases. The .security
alias always points to the
appropriate index. This index contains the data which is not available in
configuration files and cannot be reliably backed up using standard
filesystem tools. This data describes:
- the definition of users in the native realm (including hashed passwords)
- role definitions (defined via the create roles API)
- role mappings (defined via the create role mappings API)
- application privileges
- API keys
The .security
index thus contains resources and definitions in addition to
configuration information. All of that information is required in a complete
security features backup.
Use the standard Elasticsearch snapshot functionality to backup
.security
, as you would for any other data index.
For convenience, here are the complete steps:
-
Create a repository that you can use to backup the
.security
index. It is preferable to have a dedicated repository for this special index. If you wish, you can also snapshot the system indices for other Elastic Stack components to this repository.PUT /_snapshot/my_backup { "type": "fs", "settings": { "location": "my_backup_location" } }
The user calling this API must have the elevated
manage
cluster privilege to prevent non-administrators exfiltrating data. -
Create a user and assign it only the built-in
snapshot_user
role.The following example creates a new user
snapshot_user
in the native realm, but it is not important which realm the user is a member of:POST /_security/user/snapshot_user { "password" : "secret", "roles" : [ "snapshot_user" ] }
-
Create incremental snapshots authorized as
snapshot_user
.The following example shows how to use the create snapshot API to backup the
.security
index to themy_backup
repository:This parameter value captures all the persistent settings stored in the global cluster metadata as well as other configurations such as aliases and stored scripts. Note that this includes non-security configuration and that it complements but does not replace the filesystem configuration files backup.
The index format is only compatible within a single major version, and cannot be restored onto a version earlier than the version from which it originated. For example, you can restore a security snapshot from 6.6.0 into a 6.7.0 cluster, but you cannot restore it to a cluster running Elasticsearch 6.5.0 or 7.0.0.
Controlling access to the backup repository
editThe snapshot of the security index will typically contain sensitive data such as user names and password hashes. Because passwords are stored using cryptographic hashes, the disclosure of a snapshot would not automatically enable a third party to authenticate as one of your users or use API keys. However, it would disclose confidential information.
It is also important that you protect the integrity of these backups in case you ever need to restore them. If a third party is able to modify the stored backups, they may be able to install a back door that would grant access if the snapshot is loaded into an Elasticsearch cluster.
We recommend that you:
-
Snapshot the
.security
index in a dedicated repository, where read and write access is strictly restricted and audited. - If there are indications that the snapshot has been read, change the passwords of the users in the native realm and revoke API keys.
- If there are indications that the snapshot has been tampered with, do not restore it. There is currently no option for the restore process to detect malicious tampering.