Creates a unique customer managed KMS key in your Amazon Web Services account and Region. You can use a KMS key in cryptographic operations, such as encryption and signing. Some Amazon Web Services services let you use KMS keys that you create and manage to protect your service resources.
A KMS key is a logical representation of a cryptographic key. In addition to the key material used in cryptographic operations, a KMS key includes metadata, such as the key ID, key policy, creation date, description, and key state. For details, see Managing keys in the Key Management Service Developer Guide
Use the parameters of CreateKey to specify the type of KMS key, the source of its key material, its key policy, description, tags, and other properties.
KMS has replaced 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
By default, CreateKey creates a symmetric encryption KMS key with key material that KMS generates. This is the basic and most widely used type of KMS key, and provides the best performance.
To create a symmetric encryption KMS key, you don't need to specify any parameters. The default value for KeySpec, SYMMETRIC_DEFAULT, the default value for KeyUsage, ENCRYPT_DECRYPT, and the default value for Origin, AWS_KMS, create a symmetric encryption KMS key with KMS key material.
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, Elliptic Curve (ECC) key pair, or an SM2 key pair (China Regions only). 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 or SM2 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 into a KMS key, 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 instructions, see Importing key material into multi-Region keys. For more information about multi-Region keys, see Multi-Region keys in KMS in the Key Management Service Developer Guide.
Custom key store
A custom key store lets you protect your Amazon Web Services resources using keys in a backing key store that you own and manage. When you request a cryptographic operation with a KMS key in a custom key store, the operation is performed in the backing key store using its cryptographic keys.
KMS supports CloudHSM key stores backed by an CloudHSM cluster and external key stores backed by an external key manager outside of Amazon Web Services. When you create a KMS key in an CloudHSM key store, KMS generates an encryption key in the CloudHSM cluster and associates it with the KMS key. When you create a KMS key in an external key store, you specify an existing encryption key in the external key manager.
Some external key managers provide a simpler method for creating a KMS key in an external key store. For details, see your external key manager documentation.
Before you create a KMS key in a custom key store, the ConnectionState of the key store must be CONNECTED. To connect the custom key store, use the ConnectCustomKeyStore operation. To find the ConnectionState, use the DescribeCustomKeyStores operation.
To create a KMS key in a custom key store, use the CustomKeyStoreId. Use the default KeySpec value, SYMMETRIC_DEFAULT, and the default KeyUsage value, ENCRYPT_DECRYPT to create a symmetric encryption key. No other key type is supported in a custom key store.
To create a KMS key in an CloudHSM key store, 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.
To create a KMS key in an external key store, use the Origin parameter with a value of EXTERNAL_KEY_STORE and an XksKeyId parameter that identifies an existing external key.
Some external key managers provide a simpler method for creating a KMS key in an external key store. For details, see your external key manager documentation.
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:
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DescribeKey
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ListKeys
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ScheduleKeyDeletion
Headers
Request body
Response
Success
Example response
{
"KeyMetadata": {
"AWSAccountId": "111122223333",
"Arn": "arn:aws:kms:us-east-2:111122223333:key/0987dcba-09fe-87dc-65ba-ab0987654321",
"CreationDate": "2022-02-02T07:48:55-07:00",
"CustomKeyStoreId": "cks-9876543210fedcba9",
"CustomerMasterKeySpec": "SYMMETRIC_DEFAULT",
"Description": "",
"Enabled": true,
"EncryptionAlgorithms": [
"SYMMETRIC_DEFAULT"
],
"KeyId": "0987dcba-09fe-87dc-65ba-ab0987654321",
"KeyManager": "CUSTOMER",
"KeySpec": "SYMMETRIC_DEFAULT",
"KeyState": "Enabled",
"KeyUsage": "ENCRYPT_DECRYPT",
"MultiRegion": false,
"Origin": "EXTERNAL_KEY_STORE",
"XksKeyConfiguration": {
"Id": "bb8562717f809024"
}
}
}