AWS KMS Replica External Key

This page shows how to write Terraform and CloudFormation for AWS KMS Replica External Key and write them securely.


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Terraform Example (aws_replica_external kms_key)

Manages a KMS multi-Region replica key that uses external key material. See the AWS KMS Developer Guide for more information on importing key material into multi-Region keys.


The following arguments are supported:

  • bypass_policy_lockout_safety_check - (Optional) A flag to indicate whether to bypass the key policy lockout safety check. Setting this value to true increases the risk that the KMS key becomes unmanageable. Do not set this value to true indiscriminately. For more information, refer to the scenario in the Default Key Policy section in the AWS Key Management Service Developer Guide. The default value is false.
  • deletion_window_in_days - (Optional) The waiting period, specified in number of days. After the waiting period ends, AWS KMS deletes the KMS key. If you specify a value, it must be between 7 and 30, inclusive. If you do not specify a value, it defaults to 30.
  • description - (Optional) A description of the KMS key.
  • enabled - (Optional) Specifies whether the replica key is enabled. Disabled KMS keys cannot be used in cryptographic operations. Keys pending import can only be false. Imported keys default to true unless expired.
  • key_material_base64 - (Optional) Base64 encoded 256-bit symmetric encryption key material to import. The KMS key is permanently associated with this key material. The same key material can be reimported, but you cannot import different key material.
  • policy - (Optional) The key policy to attach to the KMS key. If you do not specify a key policy, AWS KMS attaches the default key policy to the KMS key. For more information about building policy documents with Terraform, see the AWS IAM Policy Document Guide.
  • primary_key_arn - (Required) The ARN of the multi-Region primary key to replicate. The primary key must be in a different AWS Region of the same AWS Partition. You can create only one replica of a given primary key in each AWS Region.
  • tags - (Optional) A map of tags to assign to the replica key. If configured with a provider default_tags configuration block present, tags with matching keys will overwrite those defined at the provider-level.
  • valid_to - (Optional) Time at which the imported key material expires. When the key material expires, AWS KMS deletes the key material and the key becomes unusable. If not specified, key material does not expire. Valid values: RFC3339 time string (YYYY-MM-DDTHH:MM:SSZ)

In addition to all arguments above, the following attributes are exported:

  • arn - The Amazon Resource Name (ARN) of the replica key. The key ARNs of related multi-Region keys differ only in the Region value.
  • expiration_model - Whether the key material expires. Empty when pending key material import, otherwise KEY_MATERIAL_EXPIRES or KEY_MATERIAL_DOES_NOT_EXPIRE.
  • key_id - The key ID of the replica key. Related multi-Region keys have the same key ID.
  • key_state - The state of the replica key.
  • key_usage - The cryptographic operations for which you can use the KMS key. This is a shared property of multi-Region keys.
  • tags_all - A map of tags assigned to the resource, including those inherited from the provider default_tags configuration block.

Example Usage (from GitHub)

An example could not be found in GitHub.

CloudFormation Example (AWS::KMS::ReplicaKey)

The AWS::KMS::ReplicaKey resource specifies a multi-Region replica key that is based on a multi-Region primary key.

Multi-Region keys are an AWS KMS feature that lets you create multiple interoperable KMS keys in different AWS Regions. Because these KMS keys have the same key ID, key material, and other metadata, you can use them to encrypt data in one AWS Region and decrypt it in a different AWS Region without making a cross-Region call or exposing the plaintext data. For more information, see Using multi-Region keys in the AWS Key Management Service Developer Guide.

A multi-Region primary key is a fully functional symmetric or asymmetric KMS key that is also the model for replica keys in other AWS Regions. To create a multi-Region primary key, add an AWS::KMS::Key resource to your CloudFormation stack. Set its MultiRegion property to true.

A multi-Region replica key is a fully functional symmetric or asymmetric KMS key that has the same key ID and key material as a multi-Region primary key, but is located in a different AWS Region of the same AWS partition. There can be multiple replicas of a primary key, but each must be in a different AWS Region .

A primary key and its replicas have the same key ID and key material. They also have the same key spec, key usage, key material origin, and automatic key rotation status. These properties are known as shared properties. If they change, AWS KMS synchronizes the change to all related multi-Region keys. All other properties of a replica key can differ, including its key policy, tags, aliases, and key state. AWS KMS does not synchronize these properties.


Frequently asked questions

What is AWS KMS Replica External Key?

AWS KMS Replica External Key is a resource for KMS of Amazon Web Service. Settings can be wrote in Terraform and CloudFormation.