Request Syntax Request Parameters Response Elements Errors Examples See Also

UpdateAlias

Associates an existing AWS KMS alias with a different KMS key. Each alias is associated with only one KMS key at a time, although a KMS key can have multiple aliases. The alias and the KMS key must be in the same AWS account and Region.

Note

Adding, deleting, or updating an alias can allow or deny permission to the KMS key. For details, see ABAC for AWS KMS in the AWS Key Management Service Developer Guide.

The current and new KMS key must be the same type (both symmetric or both asymmetric or both HMAC), and they must have the same key usage. This restriction prevents errors in code that uses aliases. If you must assign an alias to a different type of KMS key, use DeleteAlias to delete the old alias and CreateAlias to create a new alias.

You cannot use UpdateAlias to change an alias name. To change an alias name, use DeleteAlias to delete the old alias and CreateAlias to create a new alias.

Because an alias is not a property of a KMS key, you can create, update, and delete the aliases of a KMS key without affecting the KMS key. Also, aliases do not appear in the response from the DescribeKey operation. To get the aliases of all KMS keys in the account, use the ListAliases operation.

The KMS key that you use for this operation must be in a compatible key state. For details, see Key states of AWS KMS keys in the AWS Key Management Service Developer Guide.

Cross-account use: No. You cannot perform this operation on a KMS key in a different AWS account.

Required permissions

kms:UpdateAlias on the alias (IAM policy).
kms:UpdateAlias on the current KMS key (key policy).
kms:UpdateAlias on the new KMS key (key policy).

For details, see Controlling access to aliases in the AWS Key Management Service Developer Guide.

Related operations:

Eventual consistency: The AWS KMS API follows an eventual consistency model. For more information, see AWS KMS eventual consistency.

Request Syntax


{
   "AliasName": "string",
   "TargetKeyId": "string"
}

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.

Note

In the following list, the required parameters are described first.

AliasName

Identifies the alias that is changing its KMS key. This value must begin with alias/ followed by the alias name, such as alias/ExampleAlias. You cannot use UpdateAlias to change the alias name.

Important

Do not include confidential or sensitive information in this field. This field may be displayed in plaintext in CloudTrail logs and other output.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 256.

Pattern: ^alias/[a-zA-Z0-9/_-]+$

Required: Yes

TargetKeyId

Identifies the customer managed key to associate with the alias. You don't have permission to associate an alias with an AWS managed key.

The KMS key must be in the same AWS account and Region as the alias. Also, the new target KMS key must be the same type as the current target KMS key (both symmetric or both asymmetric or both HMAC) and they must have the same key usage.

Specify the key ID or key ARN of the KMS key.

For example:

Key ID: 1234abcd-12ab-34cd-56ef-1234567890ab
Key ARN: arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab

To get the key ID and key ARN for a KMS key, use ListKeys or DescribeKey.

To verify that the alias is mapped to the correct KMS key, use ListAliases.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 2048.

Required: Yes

Response Elements

If the action is successful, the service sends back an HTTP 200 response with an empty HTTP body.

Errors

For information about the errors that are common to all actions, see Common Errors.

DependencyTimeoutException

The system timed out while trying to fulfill the request. You can retry the request.

HTTP Status Code: 500

KMSInternalException

The request was rejected because an internal exception occurred. The request can be retried.

HTTP Status Code: 500

KMSInvalidStateException

The request was rejected because the state of the specified resource is not valid for this request.

This exceptions means one of the following:

The key state of the KMS key is not compatible with the operation.

To find the key state, use the DescribeKey operation. For more information about which key states are compatible with each AWS KMS operation, see Key states of AWS KMS keys in the AWS Key Management Service Developer Guide .
For cryptographic operations on KMS keys in custom key stores, this exception represents a general failure with many possible causes. To identify the cause, see the error message that accompanies the exception.

HTTP Status Code: 400

LimitExceededException

The request was rejected because a length constraint or quota was exceeded. For more information, see Quotas in the AWS Key Management Service Developer Guide.

HTTP Status Code: 400

NotFoundException

The request was rejected because the specified entity or resource could not be found.

HTTP Status Code: 400

Examples

Example Request

The following example is formatted for legibility.


POST / HTTP/1.1
Host: kms.us-east-2.amazonaws.com
Content-Length: 90
X-Amz-Target: TrentService.UpdateAlias
X-Amz-Date: 20161212T193252Z
Content-Type: application/x-amz-json-1.1
Authorization: AWS4-HMAC-SHA256\
 Credential=AKIAI44QH8DHBEXAMPLE/20161212/us-east-2/kms/aws4_request,\
 SignedHeaders=content-type;host;x-amz-date;x-amz-target,\
 Signature=3d6375048a5917aff38f25b92e66bceb16b29562193f7ab7f869b4c53f115c20

{
  "TargetKeyId": "1234abcd-12ab-34cd-56ef-1234567890ab",
  "AliasName": "alias/ExampleAlias"
}

Example Response

This example illustrates one usage of UpdateAlias.


HTTP/1.1 200 OK
Server: Server
Date: Mon, 12 Dec 2016 19:32:53 GMT
Content-Type: application/x-amz-json-1.1
Content-Length: 0
Connection: keep-alive
x-amzn-RequestId: c64706c8-c0a1-11e6-b0c0-3343f53dee45