Request Syntax Request Parameters Response Syntax Response Elements Errors Examples See Also

DescribeKey

Provides detailed information about a customer master key (CMK). You can run DescribeKey on a customer managed CMK or an AWS managed CMK.

This detailed information includes the key ARN, creation date (and deletion date, if applicable), the key state, and the origin and expiration date (if any) of the key material. For CMKs in custom key stores, it includes information about the custom key store, such as the key store ID and the AWS CloudHSM cluster ID. It includes fields, like KeySpec, that help you distinguish symmetric from asymmetric CMKs. It also provides information that is particularly important to asymmetric CMKs, such as the key usage (encryption or signing) and the encryption algorithms or signing algorithms that the CMK supports.

DescribeKey does not return the following information:

Aliases associated with the CMK. To get this information, use ListAliases.
Whether automatic key rotation is enabled on the CMK. To get this information, use GetKeyRotationStatus. Also, some key states prevent a CMK from being automatically rotated. For details, see How Automatic Key Rotation Works in AWS Key Management Service Developer Guide.
Tags on the CMK. To get this information, use ListResourceTags.
Key policies and grants on the CMK. To get this information, use GetKeyPolicy and ListGrants.

If you call the DescribeKey operation on a predefined AWS alias, that is, an AWS alias with no key ID, AWS KMS creates an AWS managed CMK. Then, it associates the alias with the new CMK, and returns the KeyId and Arn of the new CMK in the response.

Cross-account use: Yes. To perform this operation with a CMK in a different AWS account, specify the key ARN or alias ARN in the value of the KeyId parameter.

Required permissions: kms:DescribeKey (key policy)

Related operations:

Request Syntax


{
   "GrantTokens": [ "string" ],
   "KeyId": "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.

KeyId

Describes the specified customer master key (CMK).

If you specify a predefined AWS alias (an AWS alias with no key ID), KMS associates the alias with an AWS managed CMK and returns its KeyId and Arn in the response.

To specify a CMK, use its key ID, Amazon Resource Name (ARN), alias name, or alias ARN. When using an alias name, prefix it with "alias/". To specify a CMK in a different AWS account, you must use the key ARN or alias ARN.

For example:

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

To get the key ID and key ARN for a CMK, use ListKeys or DescribeKey. To get the alias name and alias ARN, use ListAliases.

Type: String

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

Required: Yes

GrantTokens

A list of grant tokens.

Use a grant token when your permission to call this operation comes from a new grant that has not yet achieved eventual consistency. For more information, see Grant token and Using a grant token in the AWS Key Management Service Developer Guide.

Type: Array of strings

Array Members: Minimum number of 0 items. Maximum number of 10 items.

Length Constraints: Minimum length of 1. Maximum length of 8192.

Required: No

Response Syntax


{
   "KeyMetadata": { 
      "Arn": "string",
      "AWSAccountId": "string",
      "CloudHsmClusterId": "string",
      "CreationDate": number,
      "CustomerMasterKeySpec": "string",
      "CustomKeyStoreId": "string",
      "DeletionDate": number,
      "Description": "string",
      "Enabled": boolean,
      "EncryptionAlgorithms": [ "string" ],
      "ExpirationModel": "string",
      "KeyId": "string",
      "KeyManager": "string",
      "KeyState": "string",
      "KeyUsage": "string",
      "Origin": "string",
      "SigningAlgorithms": [ "string" ],
      "ValidTo": number
   }
}

Response Elements

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

The following data is returned in JSON format by the service.

KeyMetadata

Metadata associated with the key.

Type: KeyMetadata object

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

InvalidArnException

The request was rejected because a specified ARN, or an ARN in a key policy, is not valid.

HTTP Status Code: 400

KMSInternalException

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

HTTP Status Code: 500

NotFoundException

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

HTTP Status Code: 400

Examples

The following examples are formatted for legibility.

Example Request

This example illustrates one usage of DescribeKey.


POST / HTTP/1.1
Host: kms.us-east-2.amazonaws.com
Content-Length: 49
X-Amz-Target: TrentService.DescribeKey
X-Amz-Date: 20170705T211529Z
Authorization: AWS4-HMAC-SHA256\
 Credential=AKIAI44QH8DHBEXAMPLE/20170705/us-east-2/kms/aws4_request,\
 SignedHeaders=content-type;host;x-amz-date;x-amz-target,\
 Signature=6bcb6a5ef9ee7585d83955e8a5c3f6d47cf581596208fc0e436fa1de26ef3f6a
Content-Type: application/x-amz-json-1.1

{"KeyId": "1234abcd-12ab-34cd-56ef-1234567890ab"}

Example Response

This example illustrates one usage of DescribeKey.


HTTP/1.1 200 OK
Server: Server
Date: Wed, 05 Jul 2017 21:15:30 GMT
Content-Type: application/x-amz-json-1.1
Content-Length: 335
Connection: keep-alive
x-amzn-RequestId: 13230ddb-61c7-11e7-af6f-c5b105d7a982

{
  "KeyMetadata": {
    "AWSAccountId": "111122223333",
    "Arn": "arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab",
    "CreationDate": 1.499288695918E9,
    "Description": "",
    "Enabled": true,
    "KeyId": "1234abcd-12ab-34cd-56ef-1234567890ab",
    "KeyManager": "CUSTOMER",
    "KeyState": "Enabled",
    "KeyUsage": "ENCRYPT_DECRYPT",
    "Origin": "AWS_KMS"
    "CustomerMasterKeySpec": "SYMMETRIC_DEFAULT",
    "EncryptionAlgorithms": [
        "SYMMETRIC_DEFAULT"
    ]
  }
}