UpdateAlias - AWS KMS
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UpdateAlias

Associates an existing Amazon KMS alias with a different customer master key (CMK). Each alias is associated with only one CMK at a time, although a CMK can have multiple aliases. The alias and the CMK must be in the same Amazon Web Services account and Region.

Note

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

The current and new CMK must be the same type (both symmetric or both asymmetric), and they must have the same key usage (ENCRYPT_DECRYPT or SIGN_VERIFY). This restriction prevents errors in code that uses aliases. If you must assign an alias to a different type of CMK, 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 CMK, you can create, update, and delete the aliases of a CMK without affecting the CMK. Also, aliases do not appear in the response from the DescribeKey operation. To get the aliases of all CMKs in the account, use the ListAliases operation.

The CMK that you use for this operation must be in a compatible key state. For details, see Key state: Effect on your CMK in the Amazon Key Management Service Developer Guide.

Cross-account use: No. You cannot perform this operation on a CMK in a different Amazon Web Services account.

Required permissions

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

Related operations:

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 CMK. This value must begin with alias/ followed by the alias name, such as alias/ExampleAlias. You cannot use UpdateAlias to change the alias name.

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 CMK to associate with the alias. You don't have permission to associate an alias with an Amazon managed CMK.

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

Specify the key ID or key ARN of the CMK.

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 CMK, use ListKeys or DescribeKey.

To verify that the alias is mapped to the correct CMK, 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. The request can be retried.

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.

For more information about how key state affects the use of a CMK, see How Key State Affects Use of a Customer Master Key in the Amazon Key Management Service Developer Guide .

HTTP Status Code: 400

LimitExceededException

The request was rejected because a quota was exceeded. For more information, see Quotas in the Amazon 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