KMS / Client / get_parameters_for_import

get_parameters_for_import#

KMS.Client.get_parameters_for_import(**kwargs)#

Returns the public key and an import token you need to import or reimport key material for a KMS key.

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.

Before calling GetParametersForImport, use the CreateKey operation with an Origin value of EXTERNAL to create a KMS key with no key material. You can import key material for 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 multi-Region key of any supported type. However, you can’t import key material into a KMS key in a custom key store. You can also use GetParametersForImport to get a public key and import token to reimport the original key material into a KMS key whose key material expired or was deleted.

GetParametersForImport returns the items that you need to import your key material.

  • The public key (or “wrapping key”) of an RSA key pair that KMS generates. You will use this public key to encrypt (“wrap”) your key material while it’s in transit to KMS.

  • A import token that ensures that KMS can decrypt your key material and associate it with the correct KMS key.

The public key and its import token are permanently linked and must be used together. Each public key and import token set is valid for 24 hours. The expiration date and time appear in the ParametersValidTo field in the GetParametersForImport response. You cannot use an expired public key or import token in an ImportKeyMaterial request. If your key and token expire, send another GetParametersForImport request.

GetParametersForImport requires the following information:

  • The key ID of the KMS key for which you are importing the key material.

  • The key spec of the public key (“wrapping key”) that you will use to encrypt your key material during import.

  • The wrapping algorithm that you will use with the public key to encrypt your key material.

You can use the same or a different public key spec and wrapping algorithm each time you import or reimport the same key material.

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:GetParametersForImport (key policy)

Related operations:

  • ImportKeyMaterial

  • DeleteImportedKeyMaterial

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

See also: AWS API Documentation

Request Syntax

response = client.get_parameters_for_import(
    KeyId='string',
    WrappingAlgorithm='RSAES_PKCS1_V1_5'|'RSAES_OAEP_SHA_1'|'RSAES_OAEP_SHA_256'|'RSA_AES_KEY_WRAP_SHA_1'|'RSA_AES_KEY_WRAP_SHA_256'|'SM2PKE',
    WrappingKeySpec='RSA_2048'|'RSA_3072'|'RSA_4096'|'SM2'
)
Parameters:

  • KeyId (string) –

    [REQUIRED]

    The identifier of the KMS key that will be associated with the imported key material. The Origin of the KMS key must be EXTERNAL.

    All KMS key types are supported, including multi-Region keys. However, you cannot import key material into a KMS key in a custom key store.

    Specify the key ID or key ARN of the KMS key.

    For example:

    • Key ID: 1234abcd-12ab-34cd-56ef-1234567890ab

    • Key ARN: arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab

    To get the key ID and key ARN for a KMS key, use ListKeys or DescribeKey.

  • WrappingAlgorithm (string) –

    [REQUIRED]

    The algorithm you will use with the RSA public key ( PublicKey) in the response to protect your key material during import. For more information, see Select a wrapping algorithm in the Key Management Service Developer Guide.

    For RSA_AES wrapping algorithms, you encrypt your key material with an AES key that you generate, then encrypt your AES key with the RSA public key from KMS. For RSAES wrapping algorithms, you encrypt your key material directly with the RSA public key from KMS.

    The wrapping algorithms that you can use depend on the type of key material that you are importing. To import an RSA private key, you must use an RSA_AES wrapping algorithm.

    • RSA_AES_KEY_WRAP_SHA_256 — Supported for wrapping RSA and ECC key material.

    • RSA_AES_KEY_WRAP_SHA_1 — Supported for wrapping RSA and ECC key material.

    • RSAES_OAEP_SHA_256 — Supported for all types of key material, except RSA key material (private key). You cannot use the RSAES_OAEP_SHA_256 wrapping algorithm with the RSA_2048 wrapping key spec to wrap ECC_NIST_P521 key material.

    • RSAES_OAEP_SHA_1 — Supported for all types of key material, except RSA key material (private key). You cannot use the RSAES_OAEP_SHA_1 wrapping algorithm with the RSA_2048 wrapping key spec to wrap ECC_NIST_P521 key material.

    • RSAES_PKCS1_V1_5 (Deprecated) — As of October 10, 2023, KMS does not support the RSAES_PKCS1_V1_5 wrapping algorithm.

  • WrappingKeySpec (string) –

    [REQUIRED]

    The type of RSA public key to return in the response. You will use this wrapping key with the specified wrapping algorithm to protect your key material during import.

    Use the longest RSA wrapping key that is practical.

    You cannot use an RSA_2048 public key to directly wrap an ECC_NIST_P521 private key. Instead, use an RSA_AES wrapping algorithm or choose a longer RSA public key.

Return type:

dict

Returns:

Response Syntax

{
    'KeyId': 'string',
    'ImportToken': b'bytes',
    'PublicKey': b'bytes',
    'ParametersValidTo': datetime(2015, 1, 1)
}

Response Structure

  • (dict) –

    • KeyId (string) –

      The Amazon Resource Name ( key ARN) of the KMS key to use in a subsequent ImportKeyMaterial request. This is the same KMS key specified in the GetParametersForImport request.

    • ImportToken (bytes) –

      The import token to send in a subsequent ImportKeyMaterial request.

    • PublicKey (bytes) –

      The public key to use to encrypt the key material before importing it with ImportKeyMaterial.

    • ParametersValidTo (datetime) –

      The time at which the import token and public key are no longer valid. After this time, you cannot use them to make an ImportKeyMaterial request and you must send another GetParametersForImport request to get new ones.

Exceptions

  • KMS.Client.exceptions.InvalidArnException

  • KMS.Client.exceptions.UnsupportedOperationException

  • KMS.Client.exceptions.DependencyTimeoutException

  • KMS.Client.exceptions.NotFoundException

  • KMS.Client.exceptions.KMSInternalException

  • KMS.Client.exceptions.KMSInvalidStateException

Examples

The following example retrieves the public key and import token for the specified KMS key.

response = client.get_parameters_for_import(
    # The identifier of the KMS key for which to retrieve the public key and import token. You can use the key ID or the Amazon Resource Name (ARN) of the KMS key.
    KeyId='1234abcd-12ab-34cd-56ef-1234567890ab',
    # The algorithm that you will use to encrypt the key material before importing it.
    WrappingAlgorithm='RSAES_OAEP_SHA_1',
    # The type of wrapping key (public key) to return in the response.
    WrappingKeySpec='RSA_2048',
)

print(response)

Expected Output:

{
    # The import token to send with a subsequent ImportKeyMaterial request.
    'ImportToken': '<binary data>',
    # The ARN of the KMS key for which you are retrieving the public key and import token. This is the same KMS key specified in the request.
    'KeyId': 'arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab',
    # The time at which the import token and public key are no longer valid.
    'ParametersValidTo': datetime(2016, 12, 1, 14, 52, 17, 3, 336, 0),
    # The public key to use to encrypt the key material before importing it.
    'PublicKey': '<binary data>',
    'ResponseMetadata': {
        '...': '...',
    },
}