[[setting-up-field-and-document-level-security]]
=== Setting Up Field and Document Level Security.

You can control access to data within an index by adding field and document level security permissions to a role.
Field level security permissions restrict access to particular fields within a document.
Document level security permissions restrict access to particular documents within an index.

Field and document level permissions are specified separately, but a role can define both field and document level permissions.
Field and document level security permissions can be configured on a per-index basis.

==== Field Level Security

To enable field level security, you specify the fields that each role can access in the `roles.yml` file.
You list the allowed fields with the `fields` option. Fields are associated with a particular index or index pattern and
operate in conjunction with the privileges specified for the indices.

[source,yaml]
--------------------------------------------------
<role_name>:
  indices:
    <index_permission_expression>:
      privileges: <privileges>
      fields:
        - <allowed_field_1>
        - <allowed_field_2>
        - <allowed_field_N>
--------------------------------------------------

To allow access to the `_all` meta field, you must explicitly list it as an allowed field. Access to the following meta fields
is always allowed: _id, _type, _parent, _routing, _timestamp, _ttl, _size and _index. If you specify an empty list of fields,
only these meta fields are accessible.

NOTE: Omitting the fields entry entirely disables field-level security.

For example, the following `customer_care` role grants read access to six fields in any index:

[source,yaml]
--------------------------------------------------
customer_care:
  indices:
    '*':
      privileges: read
      fields:
        - issue_id
        - description
        - customer_handle
        - customer_email
        - customer_address
        - customer_phone
--------------------------------------------------

Also wildcard field expressions can be added to the `fields` options in the `roles.yml` file. For example the following
example has the same effect as the previous example:

[source,yaml]
--------------------------------------------------
customer_care:
  indices:
    '*':
      privileges: read
      fields:
        - issue_id
        - description
        - 'customer_*'
--------------------------------------------------

If documents are more complex and contain json objects then the fields with dot notion should be used.

Assume the following document:

[source,json]
--------------------------------------------------
{
  "customer": {
    "handle": "Jim",
    "email": "jim@mycompany.com",
    "phone": "555-555-5555"
  }
}
--------------------------------------------------

If only access to the `handle` field is allowed then the following role should be setup:

[source,yaml]
--------------------------------------------------
my_role:
  indices:
    '*':
      privileges: read
      fields:
        - customer.handle
--------------------------------------------------

If access to the entire `customer` object is allowed then the wildcard dot notation can be used to make this easier:

[source,yaml]
--------------------------------------------------
my_role:
  indices:
    '*':
      privileges: read
      fields:
        - customer.*
--------------------------------------------------

===== Limitations

When field level security is enabled for an index:

* The get, multi get, termsvector and multi termsvector APIs aren't executed in real time. The realtime option for these APIs is forcefully set to false.
* The query cache and the request cache are disabled for search requests.
* The update API is blocked. An update request needs to be executed via a role that doesn't have field level security enabled.

==== Document Level Security

Enabling document level security restricts which documents can be accessed from any document based API.
To enable document level security, you use a query to specify the documents that each role can access in the `roles.yml` file.
You specify the document query with the `query` option. The document query is associated with a particular index or index pattern and
operates in conjunction with the privileges specified for the indices.

[source,yaml]
--------------------------------------------------
<role_name>:
  indices:
    <index_permission_expression>:
      privileges: <privileges>
      query:
        <query>
--------------------------------------------------

NOTE: Omitting the `query` entry entirely disables document-level security.

The `query` should follow the same format as if a query was defined in the request body of a search request,
but here the format is YAML. Any query from the query-dsl can be defined in the `query` entry.

For example, the following `customer_care` role grants read access to all indices, but restricts access to documents whose `department_id` equals `12`.

[source,yaml]
--------------------------------------------------
customer_care:
  indices:
    '*':
      privileges: read
      query:
        term:
         department_id: 12
--------------------------------------------------

Alternatively the query can also be defined in JSON as a string. This makes it easier to define queries that already have
been defined in the JSON body of search request body elsewhere.

[source,yaml]
--------------------------------------------------
customer_care:
  indices:
    '*':
      privileges: read
      query: '{"term" : {"department_id" : "12"}}''
--------------------------------------------------

===== Limitations

When document level security is enabled for an index:

* The get, multi get, termsvector and multi termsvector APIs aren't executed in real time. The realtime option for these APIs is forcefully set to false.
* Document level security isn't applied for APIs that aren't document based oriented. For example this is the case for the field stats API.
* Document level security doesn't affect global index statistics that relevancy scoring uses. So this means that scores are computed without taking the role query into account.
  Note that, documents not matching with the role query are never returned.
* The `has_child` and `has_parent` queries aren't supported as role query in the `roles.yml` file.
  The `has_child` and `has_parent` queries can be used in the search API with document level security enabled.