# MongoDB\Driver\ClientEncryption::createDataKey

(mongodb >=1.7.0)

MongoDB\Driver\ClientEncryption::createDataKey — Create a new encryption data key

### Description

final public MongoDB\Driver\ClientEncryption::createDataKey ( string `$kmsProvider` [, array `$options` ] ) : MongoDB\BSON\Binary

Creates a new key document and inserts it into the key vault collection.

### Parameters

`kmsProvider`

  The KMS provider (`"local"` or `"aws"`) that will be used to encrypt the new encryption key.

`options`

  Data key options
  Option | Type | Description
  --- | --- | ---
  masterKey | array | The masterKey identifies a KMS-specific key used to encrypt the new data key. If the kmsProvider is `aws` it is required and has the following fields:
  AWS masterKey options
  Option | Type | Description
  --- | --- | ---
  region | string | Required.
  key | string | Required. The Amazon Resource Name (ARN) to the AWS customer master key (CMK).
  endpoint | string | Optional. An alternate host identifier to send KMS requests to. May include port number.
  keyAltNames | array | An optional list of string alternate names used to reference a key. If a key is created with alternate names, then encryption may refer to the key by the unique alternate name instead of by `_id`.

### Return Values

Returns the identifier of the new key as a MongoDB\BSON\Binary object with subtype 4 (UUID).

### Errors/Exceptions

- Throws MongoDB\Driver\Exception\InvalidArgumentException on argument parsing errors.
- Throws MongoDB\Driver\Exception\EncryptionException if an error occurs while creating the data key