Importing key material step 1: Create an AWS KMS key without key material

By default, AWS KMS creates key material for you when you create a KMS key. To import your own key material instead, start by creating a KMS key with no key material. Then import the key material. To create a KMS key with no key material, use AWS KMS console or the CreateKey operation.

To create a key with no key material, specify an origin of EXTERNAL. The origin property of a KMS key is immutable. Once you create it, you cannot convert a KMS key designed for imported key material into a KMS key with key material from AWS KMS or any other source.

The key state of a KMS key with an EXTERNAL origin and no key material is PendingImport. A KMS key can remain in PendingImport state indefinitely. However, you cannot use a KMS key in PendingImport state in cryptographic operations. When you import key material, the key state of the KMS key changes to Enabled, and you can use it in cryptographic operations.

AWS KMS records an event in your AWS CloudTrail log when you create the KMS key, download the public key and import token, and import the key material. AWS KMS also records a CloudTrail event when you delete imported key material or when AWS KMS deletes expired key material.

For information about creating multi-Region keys with imported key material, see Importing key material into multi-Region keys.

Creating a KMS key with no key material (console)

You only need to create a KMS key for the imported key material once. You can import and reimport the same key material into the existing KMS key as often as you need to, but you cannot import different key material into a KMS key. For details, see Step 2: Download the wrapping public key and import token.

To find existing KMS keys with imported key material in your Customer managed keys table, use the gear icon in the upper right corner to show the Origin column in the list of KMS keys. Imported keys have an Origin value of External (Import Key material).

To create a KMS key with imported key material, begin by following the basic instructions for creating a KMS key of your preferred key type, with the following exception.

After choosing the key usage, do the following:

1. Expand Advanced options.

2. For Key material origin, choose External (Import key material).

3. Choose the check box next to I understand the security and durability implications of using an imported key to indicate that you understand the implications of using imported key material. To read about these implications, see Protecting imported key material.

4. Return to the basic instructions. The remaining steps of the basic procedure are the same for all KMS keys of that type.

When you choose Finish, you have created a KMS key with no key material and a status (key state) of Pending import.

However. instead of returning to the Customer managed keys table, the console displays a page where you can download the public key and import token that you need to import your key material. You can continue with the download step now, or choose Cancel to stop at this point. You can return to this download step at any time.

Next: Step 2: Download the wrapping public key and import token.

Creating a KMS key with no key material (AWS KMS API)

To use the AWS KMS API to create a symmetric encryption KMS key with no key material, send a CreateKey request with the Origin parameter set to EXTERNAL. The following example shows how to do this with the AWS Command Line Interface (AWS CLI).

$ aws kms create-key --origin EXTERNAL

When the command is successful, you see output similar to the following. The AWS KMS key's Origin is EXTERNAL and its KeyState is PendingImport.

Tip

If the command does not succeed, you might see a KMSInvalidStateException or a NotFoundException. You can retry the request.

{
    "KeyMetadata": {
        "Origin": "EXTERNAL",
        "KeyId": "1234abcd-12ab-34cd-56ef-1234567890ab",
        "Description": "",
        "Enabled": false,
        "MultiRegion": false,
        "KeyUsage": "ENCRYPT_DECRYPT",
        "KeyState": "PendingImport",
        "CreationDate": 1568289600.0,
        "Arn": "arn:aws:kms:us-west-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab",
        "AWSAccountId": "111122223333",
        "KeyManager": "CUSTOMER",
        "KeySpec": "SYMMETRIC_DEFAULT",
        "CustomerMasterKeySpec": "SYMMETRIC_DEFAULT",
        "EncryptionAlgorithms": [
            "SYMMETRIC_DEFAULT"
        ]
    }
}

Copy the KeyId value from your command output to use in later steps, and then proceed to Step 2: Download the wrapping public key and import token.

Note

This command creates a symmetric encryption KMS key with a KeySpec of SYMMETRIC_DEFAULT and KeyUsage of ENCRYPT_DECRYPT. You can use the optional parameters --key-spec and --key-usage to create an asymmetric or HMAC KMS key. For more information, see the CreateKey operation.