AWS SDK Version 3 for .NET
API Reference

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Creates a unique customer managed KMS key in your Amazon Web Services account and Region.

In addition to the required parameters, you can use the optional parameters to specify a key policy, description, tags, and other useful elements for any key type.

KMS is replacing the term customer master key (CMK) with KMS key and KMS key. The concept has not changed. To prevent breaking changes, KMS is keeping some variations of this term.

To create different types of KMS keys, use the following guidance:

Symmetric encryption KMS key

To create a symmetric encryption KMS key, you aren't required to specify any parameters. The default value for KeySpec, SYMMETRIC_DEFAULT, and the default value for KeyUsage, ENCRYPT_DECRYPT, create a symmetric encryption KMS key.

If you need a key for basic encryption and decryption or you are creating a KMS key to protect your resources in an Amazon Web Services service, create a symmetric encryption KMS key. The key material in a symmetric encryption key never leaves KMS unencrypted. You can use a symmetric encryption KMS key to encrypt and decrypt data up to 4,096 bytes, but they are typically used to generate data keys and data keys pairs. For details, see GenerateDataKey and GenerateDataKeyPair.

Asymmetric KMS keys

To create an asymmetric KMS key, use the KeySpec parameter to specify the type of key material in the KMS key. Then, use the KeyUsage parameter to determine whether the KMS key will be used to encrypt and decrypt or sign and verify. You can't change these properties after the KMS key is created.

Asymmetric KMS keys contain an RSA key pair or an Elliptic Curve (ECC) key pair. The private key in an asymmetric KMS key never leaves KMS unencrypted. However, you can use the GetPublicKey operation to download the public key so it can be used outside of KMS. KMS keys with RSA key pairs can be used to encrypt or decrypt data or sign and verify messages (but not both). KMS keys with ECC key pairs can be used only to sign and verify messages. For information about asymmetric KMS keys, see Asymmetric KMS keys in the Key Management Service Developer Guide.

HMAC KMS key

To create an HMAC KMS key, set the KeySpec parameter to a key spec value for HMAC KMS keys. Then set the KeyUsage parameter to GENERATE_VERIFY_MAC. You must set the key usage even though GENERATE_VERIFY_MAC is the only valid key usage value for HMAC KMS keys. You can't change these properties after the KMS key is created.

HMAC KMS keys are symmetric keys that never leave KMS unencrypted. You can use HMAC keys to generate (GenerateMac) and verify (VerifyMac) HMAC codes for messages up to 4096 bytes.

HMAC KMS keys are not supported in all Amazon Web Services Regions. If you try to create an HMAC KMS key in an Amazon Web Services Region in which HMAC keys are not supported, the CreateKey operation returns an UnsupportedOperationException. For a list of Regions in which HMAC KMS keys are supported, see HMAC keys in KMS in the Key Management Service Developer Guide.

Multi-Region primary keys
Imported key material

To create a multi-Region primary key in the local Amazon Web Services Region, use the MultiRegion parameter with a value of True. To create a multi-Region replica key, that is, a KMS key with the same key ID and key material as a primary key, but in a different Amazon Web Services Region, use the ReplicateKey operation. To change a replica key to a primary key, and its primary key to a replica key, use the UpdatePrimaryRegion operation.

You can create multi-Region KMS keys for all supported KMS key types: symmetric encryption KMS keys, HMAC KMS keys, asymmetric encryption KMS keys, and asymmetric signing KMS keys. You can also create multi-Region keys with imported key material. However, you can't create multi-Region keys in a custom key store.

This operation supports multi-Region keys, an KMS feature that lets you create multiple interoperable KMS keys in different Amazon Web Services Regions. Because these KMS keys have the same key ID, key material, and other metadata, you can use them interchangeably to encrypt data in one Amazon Web Services Region and decrypt it in a different Amazon Web Services Region without re-encrypting the data or making a cross-Region call. For more information about multi-Region keys, see Multi-Region keys in KMS in the Key Management Service Developer Guide.

To import your own key material, begin by creating a symmetric encryption KMS key with no key material. To do this, use the Origin parameter of CreateKey with a value of EXTERNAL. Next, use GetParametersForImport operation to get a public key and import token, and use the public key to encrypt your key material. Then, use ImportKeyMaterial with your import token to import the key material. For step-by-step instructions, see Importing Key Material in the Key Management Service Developer Guide.

This feature supports only symmetric encryption KMS keys, including multi-Region symmetric encryption KMS keys. You cannot import key material into any other type of KMS key.

To create a multi-Region primary key with imported key material, use the Origin parameter of CreateKey with a value of EXTERNAL and the MultiRegion parameter with a value of True. To create replicas of the multi-Region primary key, use the ReplicateKey operation. For more information about multi-Region keys, see Multi-Region keys in KMS in the Key Management Service Developer Guide.

Custom key store

To create a symmetric encryption KMS key in a custom key store, use the CustomKeyStoreId parameter to specify the custom key store. You must also use the Origin parameter with a value of AWS_CLOUDHSM. The CloudHSM cluster that is associated with the custom key store must have at least two active HSMs in different Availability Zones in the Amazon Web Services Region.

Custom key stores support only symmetric encryption KMS keys. You cannot create an HMAC KMS key or an asymmetric KMS key in a custom key store. For information about custom key stores in KMS see Custom key stores in KMS in the Key Management Service Developer Guide.

Cross-account use: No. You cannot use this operation to create a KMS key in a different Amazon Web Services account.

Required permissions: kms:CreateKey (IAM policy). To use the Tags parameter, kms:TagResource (IAM policy). For examples and information about related permissions, see Allow a user to create KMS keys in the Key Management Service Developer Guide.

Related operations:

Note:

For .NET Core this operation is only available in asynchronous form. Please refer to CreateKeyAsync.

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

Syntax

C#
public virtual CreateKeyResponse CreateKey(
         CreateKeyRequest request
)
Parameters
request
Type: Amazon.KeyManagementService.Model.CreateKeyRequest

Container for the necessary parameters to execute the CreateKey service method.

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

Exceptions

ExceptionCondition
CloudHsmClusterInvalidConfigurationException The request was rejected because the associated CloudHSM cluster did not meet the configuration requirements for a custom key store. The cluster must be configured with private subnets in at least two different Availability Zones in the Region. The security group for the cluster (cloudhsm-cluster--sg) must include inbound rules and outbound rules that allow TCP traffic on ports 2223-2225. The Source in the inbound rules and the Destination in the outbound rules must match the security group ID. These rules are set by default when you create the cluster. Do not delete or change them. To get information about a particular security group, use the DescribeSecurityGroups operation. The cluster must contain at least as many HSMs as the operation requires. To add HSMs, use the CloudHSM CreateHsm operation. For the CreateCustomKeyStore, UpdateCustomKeyStore, and CreateKey operations, the CloudHSM cluster must have at least two active HSMs, each in a different Availability Zone. For the ConnectCustomKeyStore operation, the CloudHSM must contain at least one active HSM. For information about the requirements for an CloudHSM cluster that is associated with a custom key store, see Assemble the Prerequisites in the Key Management Service Developer Guide. For information about creating a private subnet for an CloudHSM cluster, see Create a Private Subnet in the CloudHSM User Guide. For information about cluster security groups, see Configure a Default Security Group in the CloudHSM User Guide.
CustomKeyStoreInvalidStateException The request was rejected because of the ConnectionState of the custom key store. To get the ConnectionState of a custom key store, use the DescribeCustomKeyStores operation. This exception is thrown under the following conditions: You requested the CreateKey or GenerateRandom operation in a custom key store that is not connected. These operations are valid only when the custom key store ConnectionState is CONNECTED. You requested the UpdateCustomKeyStore or DeleteCustomKeyStore operation on a custom key store that is not disconnected. This operation is valid only when the custom key store ConnectionState is DISCONNECTED. You requested the ConnectCustomKeyStore operation on a custom key store with a ConnectionState of DISCONNECTING or FAILED. This operation is valid for all other ConnectionState values.
CustomKeyStoreNotFoundException The request was rejected because KMS cannot find a custom key store with the specified key store name or ID.
DependencyTimeoutException The system timed out while trying to fulfill the request. The request can be retried.
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.
LimitExceededException The request was rejected because a quota was exceeded. For more information, see Quotas in the Key Management Service Developer Guide.
MalformedPolicyDocumentException The request was rejected because the specified policy is not syntactically or semantically correct.
TagException The request was rejected because one or more tags are not valid.
UnsupportedOperationException The request was rejected because a specified parameter is not supported or a specified resource is not valid for this operation.

Examples

The following example creates a symmetric KMS key for encryption and decryption. No parameters are required for this operation.

To create a KMS key


var client = new AmazonKeyManagementServiceClient();
var response = client.CreateKey(new CreateKeyRequest 
{
});

KeyMetadata keyMetadata = response.KeyMetadata; // Detailed information about the KMS key that this operation creates.

            

This example creates a KMS key that contains an asymmetric RSA key pair for encryption and decryption. The key spec and key usage can't be changed after the key is created.

To create an asymmetric RSA KMS key for encryption and decryption


var client = new AmazonKeyManagementServiceClient();
var response = client.CreateKey(new CreateKeyRequest 
{
    KeySpec = "RSA_4096", // Describes the type of key material in the KMS key.
    KeyUsage = "ENCRYPT_DECRYPT" // The cryptographic operations for which you can use the KMS key.
});

KeyMetadata keyMetadata = response.KeyMetadata; // Detailed information about the KMS key that this operation creates.

            

This example creates a KMS key that contains an asymmetric elliptic curve (ECC) key pair for signing and verification. The key usage is required even though "SIGN_VERIFY" is the only valid value for ECC KMS keys. The key spec and key usage can't be changed after the key is created.

To create an asymmetric elliptic curve KMS key for signing and verification


var client = new AmazonKeyManagementServiceClient();
var response = client.CreateKey(new CreateKeyRequest 
{
    KeySpec = "ECC_NIST_P521", // Describes the type of key material in the KMS key.
    KeyUsage = "SIGN_VERIFY" // The cryptographic operations for which you can use the KMS key.
});

KeyMetadata keyMetadata = response.KeyMetadata; // Detailed information about the KMS key that this operation creates.

            

This example creates a multi-Region primary symmetric encryption key. Because the default values for all parameters create a symmetric encryption key, only the MultiRegion parameter is required for this KMS key.

To create a multi-Region primary KMS key


var client = new AmazonKeyManagementServiceClient();
var response = client.CreateKey(new CreateKeyRequest 
{
    MultiRegion = true // Indicates whether the KMS key is a multi-Region (True) or regional (False) key.
});

KeyMetadata keyMetadata = response.KeyMetadata; // Detailed information about the KMS key that this operation creates.

            

This example creates a KMS key with no key material. When the operation is complete, you can import your own key material into the KMS key. To create this KMS key, set the Origin parameter to EXTERNAL.

To create a KMS key for imported key material


var client = new AmazonKeyManagementServiceClient();
var response = client.CreateKey(new CreateKeyRequest 
{
    Origin = "EXTERNAL" // The source of the key material for the KMS key.
});

KeyMetadata keyMetadata = response.KeyMetadata; // Detailed information about the KMS key that this operation creates.

            

This example creates a KMS key in the specified custom key store. The operation creates the KMS key and its metadata in AWS KMS and the key material in the AWS CloudHSM cluster associated with the custom key store. This example requires the Origin and CustomKeyStoreId parameters.

To create a KMS key in a custom key store


var client = new AmazonKeyManagementServiceClient();
var response = client.CreateKey(new CreateKeyRequest 
{
    CustomKeyStoreId = "cks-1234567890abcdef0", // Identifies the custom key store that hosts the KMS key.
    Origin = "AWS_CLOUDHSM" // Indicates the source of the key material for the KMS key.
});

KeyMetadata keyMetadata = response.KeyMetadata; // Detailed information about the KMS key that this operation creates.

            

This example creates a 384-bit symmetric HMAC KMS key. The GENERATE_VERIFY_MAC key usage value is required even though it's the only valid value for HMAC KMS keys. The key spec and key usage can't be changed after the key is created.

To create an HMAC KMS key


var client = new AmazonKeyManagementServiceClient();
var response = client.CreateKey(new CreateKeyRequest 
{
    KeySpec = "HMAC_384", // Describes the type of key material in the KMS key.
    KeyUsage = "GENERATE_VERIFY_MAC" // The cryptographic operations for which you can use the KMS key.
});

KeyMetadata keyMetadata = response.KeyMetadata; // Detailed information about the KMS key that this operation creates.

            

Version Information

.NET Framework:
Supported in: 4.5, 4.0, 3.5

See Also