Use GenerateDataKeyWithoutPlaintext with an AWS SDK or CLI

To generate a 256-bit symmetric data key without a plaintext key

The following generate-data-key-without-plaintext example requests an encrypted copy of a 256-bit symmetric data key for use outside of AWS. You can call AWS KMS to decrypt the data key when you are ready to use it.

To request a 256-bit data key, use the key-spec parameter with a value of AES_256. To request a 128-bit data key, use the key-spec parameter with a value of AES_128. For all other data key lengths, use the number-of-bytes parameter.

The KMS key you specify must be a symmetric encryption KMS key, that is, a KMS key with a key spec value of SYMMETRIC_DEFAULT.

aws kms generate-data-key-without-plaintext \
    --key-id "arn:aws:kms:us-west-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab" \
    --key-spec AES_256

Output:

{
    "CiphertextBlob": "AQEDAHjRYf5WytIc0C857tFSnBaPn2F8DgfmThbJlGfR8P3WlwAAAH4wfAYJKoZIhvcNAQcGoG8wbQIBADBoBgkqhkiG9w0BBwEwHgYJYIZIAWUDBAEuMBEEDEFogL",
    "KeyId": "arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab"
}

The CiphertextBlob (encrypted data key) is returned in base64-encoded format.

For more information, see Data keys in the AWS Key Management Service Developer Guide.

async fn make_key(client: &Client, key: &str) -> Result<(), Error> {
    let resp = client
        .generate_data_key_without_plaintext()
        .key_id(key)
        .key_spec(DataKeySpec::Aes256)
        .send()
        .await?;

    // Did we get an encrypted blob?
    let blob = resp.ciphertext_blob.expect("Could not get encrypted text");
    let bytes = blob.as_ref();

    let s = base64::encode(bytes);

    println!();
    println!("Data key:");
    println!("{}", s);

    Ok(())
}