File-based user authentication
editFile-based user authentication
editYou can manage and authenticate users with the built-in file
realm.
With the file
realm, users are defined in local files on each node in the cluster.
As the administrator of the cluster, it is your responsibility to
ensure the same users are defined on every node in the cluster. The Elastic Stack
security features do not deliver any mechanism to guarantee this. You should
also be aware that you cannot add or manage users in the file
realm via the
user APIs and you cannot add or manage them in Kibana on the
Management / Security / Users page
The file
realm is very useful as a fallback or recovery realm. For example in cases where
the cluster is unresponsive or the security index is unavailable, or when you forget the
password for your administrative users.
In this type of scenario, the file
realm is a convenient way out - you can
define a new admin
user in the file
realm and use it to log in and reset the
credentials of all other users.
When you configure realms in elasticsearch.yml
, only the realms you
specify are used for authentication. To use the file
realm you must explicitly
include it in the realm chain.
To define users, the security features provide the users command-line tool. This tool enables you to add and remove users, assign user roles, and manage user passwords.
Configuring a file realm
editAll the data about the users for the file
realm is stored in two files on each
node in the cluster: users
and users_roles
. Both files are located in
ES_PATH_CONF
and are read on startup.
The users
and users_roles
files are managed locally by the node and are
not managed globally by the cluster. This means that with a typical
multi-node cluster, the exact same changes need to be applied on each and every
node in the cluster.
A safer approach would be to apply the change on one of the nodes and have the files distributed or copied to all other nodes in the cluster (either manually or using a configuration management system such as Puppet or Chef).
The file
realm is added to the realm chain by default. You don’t need to
explicitly configure a file
realm.
-
(Optional) Add a realm configuration to
elasticsearch.yml
under thexpack.security.authc.realms.file
namespace. At a minimum, you must set the realm’sorder
attribute.For example, the following snippet shows a
file
realm configuration that sets theorder
to zero so the realm is checked first:xpack: security: authc: realms: file: file1: order: 0
- Restart Elasticsearch.
-
Add user information to the
ES_PATH_CONF/users
file on each node in the cluster.The
users
file stores all the users and their passwords. Each line in the file represents a single user entry consisting of the username and hashed and salted password.rdeniro:$2a$10$BBJ/ILiyJ1eBTYoRKxkqbuDEdYECplvxnqQ47uiowE7yGqvCEgj9W alpacino:$2a$10$cNwHnElYiMYZ/T3K4PvzGeJ1KbpXZp2PfoQD.gfaVdImnHOwIuBKS jacknich:{PBKDF2}50000$z1CLJt0MEFjkIK5iEfgvfnA6xq7lF25uasspsTKSo5Q=$XxCVLbaKDimOdyWgLCLJiyoiWpA/XDMe/xtVgn1r5Sg=
To limit exposure to credential theft and mitigate credential compromise, the file realm stores passwords and caches user credentials according to security best practices. By default, a hashed version of user credentials is stored in memory, using a salted
sha-256
hash algorithm and a hashed version of passwords is stored on disk salted and hashed with thebcrypt
hash algorithm. To use different hash algorithms, see User cache and password hash algorithms.While it is possible to modify the
users
files directly using any standard text editor, we strongly recommend using the elasticsearch-users tool to apply the required changes.As the administrator of the cluster, it is your responsibility to ensure the same users are defined on every node in the cluster. The Elasticsearch security features do not deliver any mechanisms to guarantee this.
-
Add role information to the
ES_PATH_CONF/users_roles
file on each node in the cluster.The
users_roles
file stores the roles associated with the users. For example:admin:rdeniro power_user:alpacino,jacknich user:jacknich
Each row maps a role to a comma-separated list of all the users that are associated with that role.
You can use the elasticsearch-users tool to update this file. You must ensure that the same changes are made on every node in the cluster.
-
(Optional) Change how often the
users
andusers_roles
files are checked.By default, Elasticsearch checks these files for changes every 5 seconds. You can change this default behavior by changing the
resource.reload.interval.high
setting in theelasticsearch.yml
file (as this is a common setting in Elasticsearch, changing its value may effect other schedules in the system).