CreateKey - Amazon Key Management Service
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CreateKey

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

Note

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

You can use the CreateKey operation to create symmetric or asymmetric KMS keys.

  • Symmetric KMS keys contain a 256-bit symmetric key that never leaves Amazon KMS unencrypted. To use the KMS key, you must call Amazon KMS. You can use a symmetric KMS key to encrypt and decrypt small amounts of data, but they are typically used to generate data keys and data keys pairs. For details, see GenerateDataKey and GenerateDataKeyPair .

  • Asymmetric KMS keys can contain an RSA key pair or an Elliptic Curve (ECC) key pair. The private key in an asymmetric KMS key never leaves Amazon KMS unencrypted. However, you can use the GetPublicKey operation to download the public key so it can be used outside of Amazon 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 symmetric and asymmetric KMS keys, see Using Symmetric and Asymmetric KMS keys in the Amazon Key Management Service Developer Guide.

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

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.

Symmetric KMS keys

When creating a symmetric KMS key, you don't need to specify the KeySpec or KeyUsage parameters. The default value for KeySpec, SYMMETRIC_DEFAULT, and the default value for KeyUsage, ENCRYPT_DECRYPT, are the only valid values for symmetric KMS keys.

Multi-Region primary keys

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.

This operation supports multi-Region keys, an Amazon 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 Using multi-Region keys in the Amazon Key Management Service Developer Guide.

You can create symmetric and asymmetric multi-Region keys and multi-Region keys with imported key material. You cannot create multi-Region keys in a custom key store.

Imported key material

To import your own key material, begin by creating a symmetric 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 Amazon Key Management Service Developer Guide . You cannot import the key material into an asymmetric 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 Using multi-Region keys in the Amazon Key Management Service Developer Guide.

Custom key store

To create a symmetric 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 Amazon CloudHSM cluster that is associated with the custom key store must have at least two active HSMs in different Availability Zones in the Amazon Region.

You cannot create an asymmetric KMS key in a custom key store. For information about custom key stores in Amazon KMS see Using Custom Key Stores in the Amazon 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 Amazon Key Management Service Developer Guide.

Related operations:

Request Syntax

{ "BypassPolicyLockoutSafetyCheck": boolean, "CustomerMasterKeySpec": "string", "CustomKeyStoreId": "string", "Description": "string", "KeySpec": "string", "KeyUsage": "string", "MultiRegion": boolean, "Origin": "string", "Policy": "string", "Tags": [ { "TagKey": "string", "TagValue": "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.

BypassPolicyLockoutSafetyCheck

A flag to indicate whether to bypass the key policy lockout safety check.

Important

Setting this value to true increases the risk that the KMS key becomes unmanageable. Do not set this value to true indiscriminately.

For more information, refer to the scenario in the Default Key Policy section in the Amazon Key Management Service Developer Guide .

Use this parameter only when you include a policy in the request and you intend to prevent the principal that is making the request from making a subsequent PutKeyPolicy request on the KMS key.

The default value is false.

Type: Boolean

Required: No

CustomerMasterKeySpec

This parameter has been deprecated.

Instead, use the KeySpec parameter.

The KeySpec and CustomerMasterKeySpec parameters work the same way. Only the names differ. We recommend that you use KeySpec parameter in your code. However, to avoid breaking changes, Amazon KMS will support both parameters.

Type: String

Valid Values: RSA_2048 | RSA_3072 | RSA_4096 | ECC_NIST_P256 | ECC_NIST_P384 | ECC_NIST_P521 | ECC_SECG_P256K1 | SYMMETRIC_DEFAULT

Required: No

CustomKeyStoreId

Creates the KMS key in the specified custom key store and the key material in its associated Amazon CloudHSM cluster. To create a KMS key in a custom key store, you must also specify the Origin parameter with a value of AWS_CLOUDHSM. The Amazon CloudHSM cluster that is associated with the custom key store must have at least two active HSMs, each in a different Availability Zone in the Region.

This parameter is valid only for symmetric KMS keys and regional KMS keys. You cannot create an asymmetric KMS key or a multi-Region key in a custom key store.

To find the ID of a custom key store, use the DescribeCustomKeyStores operation.

The response includes the custom key store ID and the ID of the Amazon CloudHSM cluster.

This operation is part of the Custom Key Store feature feature in Amazon KMS, which combines the convenience and extensive integration of Amazon KMS with the isolation and control of a single-tenant key store.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 64.

Required: No

Description

A description of the KMS key.

Use a description that helps you decide whether the KMS key is appropriate for a task. The default value is an empty string (no description).

To set or change the description after the key is created, use UpdateKeyDescription .

Type: String

Length Constraints: Minimum length of 0. Maximum length of 8192.

Required: No

KeySpec

Specifies the type of KMS key to create. The default value, SYMMETRIC_DEFAULT, creates a KMS key with a 256-bit symmetric key for encryption and decryption. For help choosing a key spec for your KMS key, see How to Choose Your KMS key Configuration in the Amazon Key Management Service Developer Guide .

The KeySpec determines whether the KMS key contains a symmetric key or an asymmetric key pair. It also determines the encryption algorithms or signing algorithms that the KMS key supports. You can't change the KeySpec after the KMS key is created. To further restrict the algorithms that can be used with the KMS key, use a condition key in its key policy or IAM policy. For more information, see kms:EncryptionAlgorithm or kms:Signing Algorithm in the Amazon Key Management Service Developer Guide .

Important

Amazon services that are integrated with Amazon KMS use symmetric KMS keys to protect your data. These services do not support asymmetric KMS keys. For help determining whether a KMS key is symmetric or asymmetric, see Identifying Symmetric and Asymmetric KMS keys in the Amazon Key Management Service Developer Guide.

Amazon KMS supports the following key specs for KMS keys:

  • Symmetric key (default)

    • SYMMETRIC_DEFAULT (AES-256-GCM)

  • Asymmetric RSA key pairs

    • RSA_2048

    • RSA_3072

    • RSA_4096

  • Asymmetric NIST-recommended elliptic curve key pairs

    • ECC_NIST_P256 (secp256r1)

    • ECC_NIST_P384 (secp384r1)

    • ECC_NIST_P521 (secp521r1)

  • Other asymmetric elliptic curve key pairs

    • ECC_SECG_P256K1 (secp256k1), commonly used for cryptocurrencies.

Type: String

Valid Values: RSA_2048 | RSA_3072 | RSA_4096 | ECC_NIST_P256 | ECC_NIST_P384 | ECC_NIST_P521 | ECC_SECG_P256K1 | SYMMETRIC_DEFAULT

Required: No

KeyUsage

Determines the cryptographic operations for which you can use the KMS key. The default value is ENCRYPT_DECRYPT. This parameter is required only for asymmetric KMS keys. You can't change the KeyUsage value after the KMS key is created.

Select only one valid value.

  • For symmetric KMS keys, omit the parameter or specify ENCRYPT_DECRYPT.

  • For asymmetric KMS keys with RSA key material, specify ENCRYPT_DECRYPT or SIGN_VERIFY.

  • For asymmetric KMS keys with ECC key material, specify SIGN_VERIFY.

Type: String

Valid Values: SIGN_VERIFY | ENCRYPT_DECRYPT

Required: No

MultiRegion

Creates a multi-Region primary key that you can replicate into other Amazon Web Services Regions. You cannot change this value after you create the KMS key.

For a multi-Region key, set this parameter to True. For a single-Region KMS key, omit this parameter or set it to False. The default value is False.

This operation supports multi-Region keys, an Amazon 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 Using multi-Region keys in the Amazon Key Management Service Developer Guide.

This value creates a primary key, not a replica. To create a replica key, use the ReplicateKey operation.

You can create a symmetric or asymmetric multi-Region key, and you can create a multi-Region key with imported key material. However, you cannot create a multi-Region key in a custom key store.

Type: Boolean

Required: No

Origin

The source of the key material for the KMS key. You cannot change the origin after you create the KMS key. The default is AWS_KMS, which means that Amazon KMS creates the key material.

To create a KMS key with no key material (for imported key material), set the value to EXTERNAL. For more information about importing key material into Amazon KMS, see Importing Key Material in the Amazon Key Management Service Developer Guide. This value is valid only for symmetric KMS keys.

To create a KMS key in an Amazon KMS custom key store and create its key material in the associated Amazon CloudHSM cluster, set this value to AWS_CLOUDHSM. You must also use the CustomKeyStoreId parameter to identify the custom key store. This value is valid only for symmetric KMS keys.

Type: String

Valid Values: AWS_KMS | EXTERNAL | AWS_CLOUDHSM

Required: No

Policy

The key policy to attach to the KMS key.

If you provide a key policy, it must meet the following criteria:

  • If you don't set BypassPolicyLockoutSafetyCheck to true, the key policy must allow the principal that is making the CreateKey request to make a subsequent PutKeyPolicy request on the KMS key. This reduces the risk that the KMS key becomes unmanageable. For more information, refer to the scenario in the Default Key Policy section of the Amazon Key Management Service Developer Guide .

  • Each statement in the key policy must contain one or more principals. The principals in the key policy must exist and be visible to Amazon KMS. When you create a new Amazon principal (for example, an IAM user or role), you might need to enforce a delay before including the new principal in a key policy because the new principal might not be immediately visible to Amazon KMS. For more information, see Changes that I make are not always immediately visible in the Amazon Identity and Access Management User Guide.

If you do not provide a key policy, Amazon KMS attaches a default key policy to the KMS key. For more information, see Default Key Policy in the Amazon Key Management Service Developer Guide.

The key policy size quota is 32 kilobytes (32768 bytes).

For help writing and formatting a JSON policy document, see the IAM JSON Policy Reference in the Amazon Identity and Access Management User Guide .

Type: String

Length Constraints: Minimum length of 1. Maximum length of 32768.

Pattern: [\u0009\u000A\u000D\u0020-\u00FF]+

Required: No

Tags

Assigns one or more tags to the KMS key. Use this parameter to tag the KMS key when it is created. To tag an existing KMS key, use the TagResource operation.

Note

Tagging or untagging a KMS key can allow or deny permission to the KMS key. For details, see Using ABAC in Amazon KMS in the Amazon Key Management Service Developer Guide.

To use this parameter, you must have kms:TagResource permission in an IAM policy.

Each tag consists of a tag key and a tag value. Both the tag key and the tag value are required, but the tag value can be an empty (null) string. You cannot have more than one tag on a KMS key with the same tag key. If you specify an existing tag key with a different tag value, Amazon KMS replaces the current tag value with the specified one.

When you add tags to an Amazon resource, Amazon generates a cost allocation report with usage and costs aggregated by tags. Tags can also be used to control access to a KMS key. For details, see Tagging Keys.

Type: Array of Tag objects

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", "KeySpec": "string", "KeyState": "string", "KeyUsage": "string", "MultiRegion": boolean, "MultiRegionConfiguration": { "MultiRegionKeyType": "string", "PrimaryKey": { "Arn": "string", "Region": "string" }, "ReplicaKeys": [ { "Arn": "string", "Region": "string" } ] }, "Origin": "string", "PendingDeletionWindowInDays": number, "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 KMS key.

Type: KeyMetadata object

Errors

For information about the errors that are common to all actions, see Common Errors.

CloudHsmClusterInvalidConfigurationException

The request was rejected because the associated Amazon 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-<cluster-id>-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 Amazon CloudHSM CreateHsm operation.

    For the CreateCustomKeyStore , UpdateCustomKeyStore , and CreateKey operations, the Amazon CloudHSM cluster must have at least two active HSMs, each in a different Availability Zone. For the ConnectCustomKeyStore operation, the Amazon CloudHSM must contain at least one active HSM.

For information about the requirements for an Amazon CloudHSM cluster that is associated with a custom key store, see Assemble the Prerequisites in the Amazon Key Management Service Developer Guide. For information about creating a private subnet for an Amazon CloudHSM cluster, see Create a Private Subnet in the Amazon CloudHSM User Guide. For information about cluster security groups, see Configure a Default Security Group in the Amazon CloudHSM User Guide .

HTTP Status Code: 400

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.

HTTP Status Code: 400

CustomKeyStoreNotFoundException

The request was rejected because Amazon KMS cannot find a custom key store with the specified key store name or ID.

HTTP Status Code: 400

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

LimitExceededException

The request was rejected because a quota was exceeded. For more information, see Quotas in the Amazon Key Management Service Developer Guide.

HTTP Status Code: 400

MalformedPolicyDocumentException

The request was rejected because the specified policy is not syntactically or semantically correct.

HTTP Status Code: 400

TagException

The request was rejected because one or more tags are not valid.

HTTP Status Code: 400

UnsupportedOperationException

The request was rejected because a specified parameter is not supported or a specified resource is not valid for this operation.

HTTP Status Code: 400

Examples

The following examples are formatted for legibility.

Example Request

This example illustrates one usage of CreateKey.

POST / HTTP/1.1 Host: kms.us-east-2.amazonaws.com Content-Type: application/x-amz-json-1.1 Authorization: AWS4-HMAC-SHA256\ Credential=AKIAI44QH8DHBEXAMPLE/20170705/us-east-2/kms/aws4_request,\ SignedHeaders=content-type;host;x-amz-date;x-amz-target,\ Signature=8fb59aa17854a97df47aae69f560b66178ed0b5e1ebe334be516c4f3f59acedc X-Amz-Target: TrentService.CreateKey X-Amz-Date: 20170705T210455Z Content-Length: 62 { "Tags": [{ "TagValue": "ExampleUser", "TagKey": "CreatedBy" }] }

Example Response

This example illustrates one usage of CreateKey.

HTTP/1.1 200 OK Server: Server Date: Wed, 05 Jul 2017 21:04:55 GMT Content-Type: application/x-amz-json-1.1 Content-Length: 335 Connection: keep-alive x-amzn-RequestId: 98b2de61-61c5-11e7-bd87-9fc4a74e147b { "KeyMetadata": { "AWSAccountId": "111122223333", "Arn": "arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab", "CreationDate": 1.499288695918E9, "CustomerMasterKeySpec": "SYMMETRIC_DEFAULT", "Description": "", "Enabled": true, "EncryptionAlgorithms": [ "SYMMETRIC_DEFAULT" ], "KeyId": "1234abcd-12ab-34cd-56ef-1234567890ab", "KeyManager": "CUSTOMER", "KeySpec": "SYMMETRIC_DEFAULT", "KeyState": "Enabled", "KeyUsage": "ENCRYPT_DECRYPT", "MultiRegion": false, "Origin": "AWS_KMS" } }

See Also

For more information about using this API in one of the language-specific Amazon SDKs, see the following: