importKeyMaterial

Imports or reimports key material into an existing KMS key that was created without key material. ImportKeyMaterial also sets the expiration model and expiration date of the imported key material.

By default, KMS keys are created with key material that KMS generates. This operation supports Importing key material, an advanced feature that lets you generate and import the cryptographic key material for a KMS key. For more information about importing key material into KMS, see Importing key material in the Key Management Service Developer Guide.

After you successfully import key material into a KMS key, you can reimport the same key material into that KMS key, but you cannot import different key material. You might reimport key material to replace key material that expired or key material that you deleted. You might also reimport key material to change the expiration model or expiration date of the key material. Before reimporting key material, if necessary, call DeleteImportedKeyMaterial to delete the current imported key material.

Each time you import key material into KMS, you can determine whether (ExpirationModel) and when (ValidTo) the key material expires. To change the expiration of your key material, you must import it again, either by calling ImportKeyMaterial or using the kms/latest/developerguide/importing-keys-import-key-material.html#importing-keys-import-key-material-console of the KMS console.

Before calling ImportKeyMaterial:

• Create or identify a KMS key with no key material. The KMS key must have an Origin value of EXTERNAL, which indicates that the KMS key is designed for imported key material. To create an new KMS key for imported key material, call the CreateKey operation with an Origin value of EXTERNAL. You can create a symmetric encryption KMS key, HMAC KMS key, asymmetric encryption KMS key, or asymmetric signing KMS key. You can also import key material into a kms/latest/developerguide/multi-region-keys-overview.html of any supported type. However, you can't import key material into a KMS key in a kms/latest/developerguide/custom-key-store-overview.html.

• Use the DescribeKey operation to verify that the KeyState of the KMS key is PendingImport, which indicates that the KMS key has no key material. If you are reimporting the same key material into an existing KMS key, you might need to call the DeleteImportedKeyMaterial to delete its existing key material.

• Call the GetParametersForImport operation to get a public key and import token set for importing key material.

• Use the public key in the GetParametersForImport response to encrypt your key material.

Then, in an ImportKeyMaterial request, you submit your encrypted key material and import token. When calling this operation, you must specify the following values:

• The key ID or key ARN of the KMS key to associate with the imported key material. Its Origin must be EXTERNAL and its KeyState must be PendingImport. You cannot perform this operation on a KMS key in a kms/latest/developerguide/custom-key-store-overview.html, or on a KMS key in a different Amazon Web Services account. To get the Origin and KeyState of a KMS key, call DescribeKey.

• The encrypted key material.

• The import token that GetParametersForImport returned. You must use a public key and token from the same GetParametersForImport response.

• Whether the key material expires (ExpirationModel) and, if so, when (ValidTo). For help with this choice, see Setting an expiration time in the Key Management Service Developer Guide.If you set an expiration date, KMS deletes the key material from the KMS key on the specified date, making the KMS key unusable. To use the KMS key in cryptographic operations again, you must reimport the same key material. However, you can delete and reimport the key material at any time, including before the key material expires. Each time you reimport, you can eliminate or reset the expiration time.

When this operation is successful, the key state of the KMS key changes from PendingImport to Enabled, and you can use the KMS key in cryptographic operations.

If this operation fails, use the exception to help determine the problem. If the error is related to the key material, the import token, or wrapping key, use GetParametersForImport to get a new public key and import token for the KMS key and repeat the import procedure. For help, see How To Import Key Material in the Key Management Service Developer Guide.

The KMS key that you use for this operation must be in a compatible key state. For details, see Key states of KMS keys in the Key Management Service Developer Guide.

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

Required permissions: kms:ImportKeyMaterial (key policy)

Related operations:

• DeleteImportedKeyMaterial

• GetParametersForImport

Eventual consistency: The KMS API follows an eventual consistency model. For more information, see KMS eventual consistency.

Samples

fun main() { 
   //sampleStart 
   // The following example imports key material into the specified KMS key.
kmsClient.importKeyMaterial {
    keyId = "1234abcd-12ab-34cd-56ef-1234567890ab"
    importToken = "<binary data>".encodeAsByteArray()
    encryptedKeyMaterial = "<binary data>".encodeAsByteArray()
    expirationModel = ExpirationModelType.fromValue("KEY_MATERIAL_DOES_NOT_EXPIRE")
} 
   //sampleEnd
}