Use DescribeKey with an AWS SDK or CLI

    using System;
    using System.Threading.Tasks;
    using Amazon.KeyManagementService;
    using Amazon.KeyManagementService.Model;

    /// <summary>
    /// Retrieve information about an AWS Key Management Service (AWS KMS) key.
    /// You can supply either the key Id or the key Amazon Resource Name (ARN)
    /// to the DescribeKeyRequest KeyId property.
    /// </summary>
    public class DescribeKey
    {
        public static async Task Main()
        {
            var keyId = "7c9eccc2-38cb-4c4f-9db3-766ee8dd3ad4";
            var request = new DescribeKeyRequest
            {
                KeyId = keyId,
            };

            var client = new AmazonKeyManagementServiceClient();

            var response = await client.DescribeKeyAsync(request);
            var metadata = response.KeyMetadata;

            Console.WriteLine($"{metadata.KeyId} created on: {metadata.CreationDate}");
            Console.WriteLine($"State: {metadata.KeyState}");
            Console.WriteLine($"{metadata.Description}");
        }
    }

Example 1: To find detailed information about a KMS key

The following describe-key example gets detailed information about the AWS managed key for Amazon S3 in the example account and Region. You can use this command to find details about AWS managed keys and customer managed keys.

To specify the KMS key, use the key-id parameter. This example uses an alias name value, but you can use a key ID, key ARN, alias name, or alias ARN in this command.

<userinput>aws kms describe-key \
    --key-id <replaceable>alias/aws/s3</replaceable></userinput>

Output:

{
    "KeyMetadata": {
        "AWSAccountId": "846764612917",
        "KeyId": "b8a9477d-836c-491f-857e-07937918959b",
        "Arn": "arn:aws:kms:us-west-2:846764612917:key/b8a9477d-836c-491f-857e-07937918959b",
        "CreationDate": 2017-06-30T21:44:32.140000+00:00,
        "Enabled": true,
        "Description": "Default KMS key that protects my S3 objects when no other key is defined",
        "KeyUsage": "ENCRYPT_DECRYPT",
        "KeyState": "Enabled",
        "Origin": "AWS_KMS",
        "KeyManager": "AWS",
        "CustomerMasterKeySpec": "SYMMETRIC_DEFAULT",
        "EncryptionAlgorithms": [
            "SYMMETRIC_DEFAULT"
        ]
    }
}

For more information, see Viewing keys in the AWS Key Management Service Developer Guide.

Example 2: To get details about an RSA asymmetric KMS key

The following describe-key example gets detailed information about an asymmetric RSA KMS key used for signing and verification.

<userinput>aws kms describe-key \
    --key-id <replaceable>1234abcd-12ab-34cd-56ef-1234567890ab</replaceable></userinput>

Output:

{
    "KeyMetadata": {
        "AWSAccountId": "111122223333",
        "KeyId": "1234abcd-12ab-34cd-56ef-1234567890ab",
        "Arn": "arn:aws:kms:us-west-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab",
        "CreationDate": "2019-12-02T19:47:14.861000+00:00",
        "CustomerMasterKeySpec": "RSA_2048",
        "Enabled": false,
        "Description": "",
        "KeyState": "Disabled",
        "Origin": "AWS_KMS",
        "MultiRegion": false,
        "KeyManager": "CUSTOMER",
        "KeySpec": "RSA_2048",
        "KeyUsage": "SIGN_VERIFY",
        "SigningAlgorithms": [
            "RSASSA_PKCS1_V1_5_SHA_256",
            "RSASSA_PKCS1_V1_5_SHA_384",
            "RSASSA_PKCS1_V1_5_SHA_512",
            "RSASSA_PSS_SHA_256",
            "RSASSA_PSS_SHA_384",
            "RSASSA_PSS_SHA_512"
        ]
    }
}

Example 3: To get details about a multi-Region replica key

The following describe-key example gets metadata for a multi-Region replica key. This multi-Region key is a symmetric encryption key. The output of a describe-key command for any multi-Region key returns information about the primary key and all of its replicas.

<userinput>aws kms describe-key \
    --key-id <replaceable>arn:aws:kms:ap-northeast-1:111122223333:key/mrk-1234abcd12ab34cd56ef1234567890ab</replaceable></userinput>

Output:

{
    "KeyMetadata": {
        "MultiRegion": true,
        "AWSAccountId": "111122223333",
        "Arn": "arn:aws:kms:ap-northeast-1:111122223333:key/mrk-1234abcd12ab34cd56ef1234567890ab",
        "CreationDate": "2021-06-28T21:09:16.114000+00:00",
        "Description": "",
        "Enabled": true,
        "KeyId": "mrk-1234abcd12ab34cd56ef1234567890ab",
        "KeyManager": "CUSTOMER",
        "KeyState": "Enabled",
        "KeyUsage": "ENCRYPT_DECRYPT",
        "Origin": "AWS_KMS",
        "CustomerMasterKeySpec": "SYMMETRIC_DEFAULT",
        "EncryptionAlgorithms": [
            "SYMMETRIC_DEFAULT"
        ],
        "MultiRegionConfiguration": {
            "MultiRegionKeyType": "PRIMARY",
            "PrimaryKey": {
                "Arn": "arn:aws:kms:us-west-2:111122223333:key/mrk-1234abcd12ab34cd56ef1234567890ab",
                "Region": "us-west-2"
            },
            "ReplicaKeys": [
                {
                    "Arn": "arn:aws:kms:eu-west-1:111122223333:key/mrk-1234abcd12ab34cd56ef1234567890ab",
                    "Region": "eu-west-1"
                },
                {
                    "Arn": "arn:aws:kms:ap-northeast-1:111122223333:key/mrk-1234abcd12ab34cd56ef1234567890ab",
                    "Region": "ap-northeast-1"
                },
                {
                    "Arn": "arn:aws:kms:sa-east-1:111122223333:key/mrk-1234abcd12ab34cd56ef1234567890ab",
                    "Region": "sa-east-1"
                }
            ]
        }
    }
}

Example 4: To get details about an HMAC KMS key

The following describe-key example gets detailed information about an HMAC KMS key.

<userinput>aws kms describe-key \
    --key-id <replaceable>1234abcd-12ab-34cd-56ef-1234567890ab</replaceable></userinput>

Output:

{
    "KeyMetadata": {
        "AWSAccountId": "123456789012",
        "KeyId": "1234abcd-12ab-34cd-56ef-1234567890ab",
        "Arn": "arn:aws:kms:us-west-2:123456789012:key/1234abcd-12ab-34cd-56ef-1234567890ab",
        "CreationDate": "2022-04-03T22:23:10.194000+00:00",
        "Enabled": true,
        "Description": "Test key",
        "KeyUsage": "GENERATE_VERIFY_MAC",
        "KeyState": "Enabled",
        "Origin": "AWS_KMS",
        "KeyManager": "CUSTOMER",
        "CustomerMasterKeySpec": "HMAC_256",
        "MacAlgorithms": [
            "HMAC_SHA_256"
        ],
        "MultiRegion": false
    }
}

    public static boolean isKeyEnabled(KmsClient kmsClient, String keyId) {
        try {
            DescribeKeyRequest keyRequest = DescribeKeyRequest.builder()
                .keyId(keyId)
                .build();

            DescribeKeyResponse response = kmsClient.describeKey(keyRequest);
            KeyState keyState = response.keyMetadata().keyState();
            if (keyState == KeyState.ENABLED) {
                System.out.println("The key is enabled.");
                return true;
            } else {
                System.out.println("The key is not enabled. Key state: " + keyState);
            }

        } catch (KmsException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
        return false;
    }

suspend fun describeSpecifcKey(keyIdVal: String?) {
    val request =
        DescribeKeyRequest {
            keyId = keyIdVal
        }

    KmsClient { region = "us-west-2" }.use { kmsClient ->
        val response = kmsClient.describeKey(request)
        println("The key description is ${response.keyMetadata?.description}")
        println("The key ARN is ${response.keyMetadata?.arn}")
    }
}

class KeyManager:
    def __init__(self, kms_client):
        self.kms_client = kms_client
        self.created_keys = []


    def describe_key(self):
        """
        Describes a key.
        """
        key_id = input("Enter a key ID or ARN here to get information about the key: ")
        if key_id:
            try:
                key = self.kms_client.describe_key(KeyId=key_id)["KeyMetadata"]
            except ClientError as err:
                logging.error(
                    "Couldn't get key '%s'. Here's why: %s",
                    key_id,
                    err.response["Error"]["Message"],
                )
            else:
                print(f"Got key {key_id}:")
                pprint(key)
        return key_id