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    Key Management Service:GenerateAndExportDataKey

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    Key Management Service:GenerateAndExportDataKey

    Last Updated:Sep 13, 2024

    Randomly generates a data key and uses a Key Management Service (KMS) key and a public key to encrypt the data key. This operation returns the ciphertext of the data key that is encrypted by using the key and the ciphertext of the data key that is encrypted by using the public key.

    Usage notes

    • Keys outside KMS instances: To perform cryptographic operations, use Alibaba Cloud SDK to call operations.
    • Keys in KMS instances: To perform cryptographic operations, use one of the following methods:

    Limits

    You can call this operation up to 750 times per second per account. If the number of calls per second exceeds the limit, throttling is triggered. As a result, your business may be affected. We recommend that you take note of the limit when you call this operation.

    Description

    We recommend that you perform the following steps to import your data key to a cryptographic module:

    1. Call the GenerateAndExportDataKey operation to obtain the ciphertext of the data key that is encrypted by using a KMS key and the ciphertext of the data key that is encrypted by using a public key.

    2. Store the ciphertext of the data key that is encrypted by using a key in KMS or in a storage service such as ApsaraDB. This ciphertext is used for backup and restoration.

    3. Import the ciphertext of the data key that is encrypted by using the public key to a cryptographic module where paired private keys are stored. This way, the data key is distributed from KMS to the cryptographic module. You can use the data key to encrypt or decrypt data.

    Note The KMS key that you specify in the request of this operation is used to only encrypt the data key and is not involved in the generation of the data key. KMS does not record or store the data key that is randomly generated by calling this operation. You must take note of the data key and the returned data key ciphertext.

    Debugging

    OpenAPI Explorer automatically calculates the signature value. For your convenience, we recommend that you call this operation in OpenAPI Explorer. OpenAPI Explorer dynamically generates the sample code of the operation for different SDKs.

    Request parameters

    Parameter

    Type

    Required

    Example

    Description
    Action String Yes GenerateAndExportDataKey

    The operation that you want to perform. Set the value to GenerateAndExportDataKey.

    KeyId String Yes 1234abcd-12ab-34cd-56ef-12345678****

    The ID, alias, or Alibaba Cloud Resource Name (ARN) of the key. For more information, see Manage a key alias.

    Note When you access a key within another Alibaba Cloud account, you must enter the ARN of the key. The ARN of the key is in the acs:kms:${region}:${account}:key/${keyid} format.
    KeySpec String No AES_256

    The type of the data key that you want to generate. Valid values:

    • AES_256: a 256-bit symmetric key.
    • AES_128: a 128-bit symmetric key.
    Note We recommend that you use KeySpec or NumberOfBytes to specify the length of a data key. If none of the parameters are specified, KMS generates a 256-bit data key. If both parameters are specified, KMS ignores the KeySpec parameter.
    NumberOfBytes Integer No 32

    The length of the data key that you want to generate.

    Valid values: 1 to 1024.

    Unit: bytes.

    EncryptionContext Map No {"Example":"Example"}

    The JSON string that consists of key-value pairs. If you specify this parameter, an equivalent value is required when you decrypt or re-encrypt the data key. For more information, see EncryptionContext.

    PublicKeyBlob String Yes MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAndKfC2ReLL2+y8a0+ZBBeAft/uBYo86GZiYJuflqgUzKxpyuvlo3uQkBv6b+nx+0tz8g8v7GhpPWMSW5L9mNHYsvYFsa7jTxsYdt17yj6GlUHPuMIs8hr5qbwl38IHU1iIa7nYWwE2fb3ePOvLDACRJVgGpU0yxioW80d2QD+9aU4jF5dlAahcfgsNzo2CXzCUc1+xbmNuq7Rp+H9VJB9dyYOwqnW3RhOLBo21FzpORapf0UiRlrHRpk1V6ez+aE1dofaYh/9bh0m6ioxj7j5hpZbWccuEZTMBKd+cbuBkRhJzc6Tti6qwZbDiu4fUwbZS0Tqpuo1UadiyxMW********

    The Base64-encoded public key.

    WrappingKeySpec String Yes RSA_2048

    The type of the public key specified by PublicKeyBlob. For more information about key types, see Introduction to asymmetric keys.

    Valid values:

    • RSA_2048
    • EC_SM2
    WrappingAlgorithm String Yes RSAES_OAEP_SHA_256

    The encryption algorithm based on which you use the public key specified by PublicKeyBlob to encrypt the data key. For more information about encryption algorithms, see AsymmetricDecrypt.

    Valid values:

    • RSAES_OAEP_SHA_256
    • RSAES_OAEP_SHA_1
    • SM2PKE
    DryRun String No false

    Specifies whether to perform a dry run. Valid values:

    • true
    • false (default)

    A dry run is used for testing in API calls. You can perform a dry run to check whether you have the permissions to access the resources that you want to manage and whether the request parameters are correctly configured. If you set DryRun to true in the request, KMS always returns an error code that indicates the cause of the error. KMS may return the following error codes:

    • DryRunOperationError: The request passes the dry run. If you do not configure the DryRun parameter and retain the other parameter configurations to call the same operation, the operation will be performed.
    • ValidationError: A parameter value in the request is invalid.
    • AccessDeniedError: You do not have the permissions to access the resources that you want to manage.

    Response parameters

    Parameter

    Type

    Example

    Description
    KeyVersionId String 2ab1a983-7072-4bbc-a582-584b5bd8****

    The version ID of the key that is used to encrypt the plaintext. The primary version of the key is returned.

    KeyId String 599fa825-17de-417e-9554-bb032cc6****

    The ID of the key. If KeyId is set to the alias or ARN of the key, the ID of the key is returned.

    CiphertextBlob String ODZhOWVmZDktM2QxNi00ODk0LWJkNGYtMWZjNDNmM2YyYWJmS7FmDBBQ0BkKsQrtRnidtPwirmDcS0ZuJCU41xxAAWk4Z8qsADfbV0b+i6kQmlvj79dJdGOvtX69Uycs901qOjop4bTS****

    The ciphertext of the data key that is encrypted by using the primary version of the key.

    RequestId String 7021b6ec-4be7-4d3c-8a68-1e85d4d515a0

    The request ID.

    ExportedDataKey String BQKP+1zK6+ZEMxTP5qaVzcsgXtWplYBKm0NXdSnB5FzliFxE1bSiu4dnEIlca2JpeH7yz1/S6fed630H+hIH6DoM25fTLNcKj+mFB0Xnh9m2+HN59Mn4qyTfcUeadnfCXSWcGBouhXFwcdd2rJ3n337bzTf4jm659gZu3L0i6PLuxM9p7mqdwO0cKJPfGVfhnfMz+f4alMg79WB/NNyE2lyX7/qxvV49ObNrrJbKSFiz8Djocaf0IESNLMbfYI5bXjWkJlX92DQbKhibtQW8ZOJ//ZC6t0AWcUoKL6QDm/dg5koQalcleRinpB+QadFm894sLbVZ9+N4GVs*******

    The ciphertext of the data key that is encrypted by using the public key.

    Examples

    Sample requests

    http(s)://[Endpoint]/?Action=GenerateAndExportDataKey
&KeyId=1234abcd-12ab-34cd-56ef-12345678****
&KeySpec=AES_256
&NumberOfBytes=32
&PublicKeyBlob=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAndKfC2ReLL2+y8a0+ZBBeAft/uBYo86GZiYJuflqgUzKxpyuvlo3uQkBv6b+nx+0tz8g8v7GhpPWMSW5L9mNHYsvYFsa7jTxsYdt17yj6GlUHPuMIs8hr5qbwl38IHU1iIa7nYWwE2fb3ePOvLDACRJVgGpU0yxioW80d2QD+9aU4jF5dlAahcfgsNzo2CXzCUc1+xbmNuq7Rp+H9VJB9dyYOwqnW3RhOLBo21FzpORapf0UiRlrHRpk1V6ez+aE1dofaYh/9bh0m6ioxj7j5hpZbWccuEZTMBKd+cbuBkRhJzc6Tti6qwZbDiu4fUwbZS0Tqpuo1UadiyxMW********
&WrappingKeySpec=RSA_2048
&WrappingAlgorithm=RSAES_OAEP_SHA_256
&DryRun=false
&<Common request parameters>

    Sample success responses

    XML format

    HTTP/1.1 200 OK
Content-Type:application/xml

<GenerateAndExportDataKeyResponse>
    <KeyVersionId>2ab1a983-7072-4bbc-a582-584b5bd8****</KeyVersionId>
    <KeyId>599fa825-17de-417e-9554-bb032cc6****</KeyId>
    <CiphertextBlob>ODZhOWVmZDktM2QxNi00ODk0LWJkNGYtMWZjNDNmM2YyYWJmS7FmDBBQ0BkKsQrtRnidtPwirmDcS0ZuJCU41xxAAWk4Z8qsADfbV0b+i6kQmlvj79dJdGOvtX69Uycs901qOjop4bTS****</CiphertextBlob>
    <RequestId>7021b6ec-4be7-4d3c-8a68-1e85d4d515a0</RequestId>
    <ExportedDataKey>BQKP+1zK6+ZEMxTP5qaVzcsgXtWplYBKm0NXdSnB5FzliFxE1bSiu4dnEIlca2JpeH7yz1/S6fed630H+hIH6DoM25fTLNcKj+mFB0Xnh9m2+HN59Mn4qyTfcUeadnfCXSWcGBouhXFwcdd2rJ3n337bzTf4jm659gZu3L0i6PLuxM9p7mqdwO0cKJPfGVfhnfMz+f4alMg79WB/NNyE2lyX7/qxvV49ObNrrJbKSFiz8Djocaf0IESNLMbfYI5bXjWkJlX92DQbKhibtQW8ZOJ//ZC6t0AWcUoKL6QDm/dg5koQalcleRinpB+QadFm894sLbVZ9+N4GVs*******</ExportedDataKey>
</GenerateAndExportDataKeyResponse>

    JSON format

    HTTP/1.1 200 OK
Content-Type:application/json

{
  "KeyVersionId" : "2ab1a983-7072-4bbc-a582-584b5bd8****",
  "KeyId" : "599fa825-17de-417e-9554-bb032cc6****",
  "CiphertextBlob" : "ODZhOWVmZDktM2QxNi00ODk0LWJkNGYtMWZjNDNmM2YyYWJmS7FmDBBQ0BkKsQrtRnidtPwirmDcS0ZuJCU41xxAAWk4Z8qsADfbV0b+i6kQmlvj79dJdGOvtX69Uycs901qOjop4bTS****",
  "RequestId" : "7021b6ec-4be7-4d3c-8a68-1e85d4d515a0",
  "ExportedDataKey" : "BQKP+1zK6+ZEMxTP5qaVzcsgXtWplYBKm0NXdSnB5FzliFxE1bSiu4dnEIlca2JpeH7yz1/S6fed630H+hIH6DoM25fTLNcKj+mFB0Xnh9m2+HN59Mn4qyTfcUeadnfCXSWcGBouhXFwcdd2rJ3n337bzTf4jm659gZu3L0i6PLuxM9p7mqdwO0cKJPfGVfhnfMz+f4alMg79WB/NNyE2lyX7/qxvV49ObNrrJbKSFiz8Djocaf0IESNLMbfYI5bXjWkJlX92DQbKhibtQW8ZOJ//ZC6t0AWcUoKL6QDm/dg5koQalcleRinpB+QadFm894sLbVZ9+N4GVs*******"
}

    Error codes

    HttpCode

    Error code

    Error message

    Description
    400 InvalidParameter The specified parameter is not valid. The specified parameter is invalid.
    404 Forbidden.KeyNotFound The specified Key is not found. The specified key does not exist.

    For a list of error codes, see Service error codes.