AWS SDK Version 3 for .NET
API Reference

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Provides detailed information about a KMS key. You can run DescribeKey on a customer managed key or an Amazon Web Services managed key.

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. It includes fields, like KeySpec, that help you distinguish different types of KMS keys. It also displays the key usage (encryption, signing, or generating and verifying MACs) and the algorithms that the KMS key supports.

For multi-Region keys, DescribeKey displays the primary key and all related replica keys. For KMS keys in CloudHSM key stores, it includes information about the key store, such as the key store ID and the CloudHSM cluster ID. For KMS keys in external key stores, it includes the custom key store ID and the ID of the external key.

DescribeKey does not return the following information:

In general, DescribeKey is a non-mutating operation. It returns data about KMS keys, but doesn't change them. However, Amazon Web Services services use DescribeKey to create Amazon Web Services managed keys from a predefined Amazon Web Services alias with no key ID.

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

Required permissions: kms:DescribeKey (key policy)

Related operations:


This is an asynchronous operation using the standard naming convention for .NET 4.5 or higher. For .NET 3.5 the operation is implemented as a pair of methods using the standard naming convention of BeginDescribeKey and EndDescribeKey.

Namespace: Amazon.KeyManagementService
Assembly: AWSSDK.KeyManagementService.dll
Version: 3.x.y.z


public virtual Task<DescribeKeyResponse> DescribeKeyAsync(
         String keyId,
         CancellationToken cancellationToken
Type: System.String

Describes the specified KMS key. If you specify a predefined Amazon Web Services alias (an Amazon Web Services alias with no key ID), KMS associates the alias with an Amazon Web Services managed key and returns its KeyId and Arn in the response. To specify a KMS key, use its key ID, key ARN, alias name, or alias ARN. When using an alias name, prefix it with "alias/". To specify a KMS key in a different Amazon Web Services 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 KMS key, use ListKeys or DescribeKey. To get the alias name and alias ARN, use ListAliases.

Type: System.Threading.CancellationToken

A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Return Value
The response from the DescribeKey service method, as returned by KeyManagementService.


DependencyTimeoutException The system timed out while trying to fulfill the request. You can retry the request.
InvalidArnException The request was rejected because a specified ARN, or an ARN in a key policy, is not valid.
KMSInternalException The request was rejected because an internal exception occurred. The request can be retried.
NotFoundException The request was rejected because the specified entity or resource could not be found.

Version Information

.NET Core App:
Supported in: 3.1

.NET Standard:
Supported in: 2.0

.NET Framework:
Supported in: 4.5

See Also