generate_data_key_without_plaintext¶
Operation¶
async
¶
generate_data_key_without_plaintext(input: GenerateDataKeyWithoutPlaintextInput, plugins: list[Plugin] | None = None) -> GenerateDataKeyWithoutPlaintextOutput
Returns a unique symmetric data key for use outside of KMS. This operation returns a data key that is encrypted under a symmetric encryption KMS key that you specify. The bytes in the key are random; they are not related to the caller or to the KMS key.
GenerateDataKeyWithoutPlaintext is identical to the GenerateDataKey
operation except that it does not return a plaintext copy of the data
key.
This operation is useful for systems that need to encrypt data at some point, but not immediately. When you need to encrypt the data, you call the Decrypt operation on the encrypted copy of the key.
It's also useful in distributed systems with different levels of trust. For example, you might store encrypted data in containers. One component of your system creates new containers and stores an encrypted data key with each container. Then, a different component puts the data into the containers. That component first decrypts the data key, uses the plaintext data key to encrypt data, puts the encrypted data into the container, and then destroys the plaintext data key. In this system, the component that creates the containers never sees the plaintext data key.
To request an asymmetric data key pair, use the GenerateDataKeyPair or GenerateDataKeyPairWithoutPlaintext operations.
To generate a data key, you must specify the symmetric encryption KMS key that is used to encrypt the data key. You cannot use an asymmetric KMS key or a key in a custom key store to generate a data key. To get the type of your KMS key, use the DescribeKey operation.
You must also specify the length of the data key. Use either the
KeySpec or NumberOfBytes parameters (but not both). For 128-bit and
256-bit data keys, use the KeySpec parameter.
To generate an SM4 data key (China Regions only), specify a KeySpec
value of AES_128 or NumberOfBytes value of 16. The symmetric
encryption key used in China Regions to encrypt your data key is an SM4
encryption key.
If the operation succeeds, you will find the encrypted copy of the data
key in the CiphertextBlob field.
You can use an optional encryption context to add additional security to
the encryption operation. If you specify an EncryptionContext, you
must specify the same encryption context (a case-sensitive exact match)
when decrypting the encrypted data key. Otherwise, the request to
decrypt fails with an InvalidCiphertextException. For more
information, see Encryption
Context
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: Yes. To perform this operation with a KMS key in
a different Amazon Web Services account, specify the key ARN or alias
ARN in the value of the KeyId parameter.
Required permissions: kms:GenerateDataKeyWithoutPlaintext (key policy)
Related operations:
-
Decrypt
-
Encrypt
-
GenerateDataKey
-
GenerateDataKeyPair
-
GenerateDataKeyPairWithoutPlaintext
Eventual consistency: The KMS API follows an eventual consistency model. For more information, see KMS eventual consistency.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
input
|
GenerateDataKeyWithoutPlaintextInput
|
An instance of |
required |
plugins
|
list[Plugin] | None
|
A list of callables that modify the configuration dynamically. Changes made by these plugins only apply for the duration of the operation execution and will not affect any other operation invocations. |
None
|
Returns:
| Type | Description |
|---|---|
GenerateDataKeyWithoutPlaintextOutput
|
An instance of |
Input¶
dataclass
¶
Bases: _SerdeShape
Dataclass for GenerateDataKeyWithoutPlaintextInput structure.
Attributes¶
class-attribute
instance-attribute
¶
dry_run: bool | None = ...
Checks if your request will succeed. DryRun is an optional parameter.
To learn more about how to use this parameter, see Testing your permissions in the Key Management Service Developer Guide.
class-attribute
instance-attribute
¶
Specifies the encryption context that will be used when encrypting the data key.
Warning
Do not include confidential or sensitive information in this field. This field may be displayed in plaintext in CloudTrail logs and other output.
An encryption context is a collection of non-secret key-value pairs that represent additional authenticated data. When you use an encryption context to encrypt data, you must specify the same (an exact case-sensitive match) encryption context to decrypt the data. An encryption context is supported only on operations with symmetric encryption KMS keys. On operations with symmetric encryption KMS keys, an encryption context is optional, but it is strongly recommended.
For more information, see Encryption context in the Key Management Service Developer Guide.
class-attribute
instance-attribute
¶
A list of grant tokens.
Use a grant token when your permission to call this operation comes from a new grant that has not yet achieved eventual consistency. For more information, see Grant token and Using a grant token in the Key Management Service Developer Guide.
class-attribute
instance-attribute
¶
key_id: str | None = ...
Specifies the symmetric encryption KMS key that encrypts the data key. You cannot specify an asymmetric KMS key or a KMS key in a custom key store. To get the type and origin of your KMS key, use the DescribeKey operation.
To specify a KMS key, use its key ID, key ARN, alias name, or alias ARN.
When using an alias name, prefix it with "alias/". To specify a KMS
key in a different Amazon Web Services account, you must use the key ARN
or alias ARN.
For example:
-
Key ID:
1234abcd-12ab-34cd-56ef-1234567890ab -
Key ARN:
arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab -
Alias name:
alias/ExampleAlias -
Alias ARN:
arn:aws:kms:us-east-2:111122223333:alias/ExampleAlias
To get the key ID and key ARN for a KMS key, use ListKeys or DescribeKey. To get the alias name and alias ARN, use ListAliases.
class-attribute
instance-attribute
¶
key_spec: str | None = ...
The length of the data key. Use AES_128 to generate a 128-bit
symmetric key, or AES_256 to generate a 256-bit symmetric key.
class-attribute
instance-attribute
¶
number_of_bytes: int | None = ...
The length of the data key in bytes. For example, use the value 64 to
generate a 512-bit data key (64 bytes is 512 bits). For common key
lengths (128-bit and 256-bit symmetric keys), we recommend that you use
the KeySpec field instead of this one.
Output¶
dataclass
¶
Bases: _SerdeShape
Dataclass for GenerateDataKeyWithoutPlaintextOutput structure.
Attributes¶
class-attribute
instance-attribute
¶
ciphertext_blob: bytes | None = ...
The encrypted data key. When you use the HTTP API or the Amazon Web Services CLI, the value is Base64-encoded. Otherwise, it is not Base64-encoded.
class-attribute
instance-attribute
¶
key_id: str | None = ...
The Amazon Resource Name (key ARN) of the KMS key that encrypted the data key.
class-attribute
instance-attribute
¶
key_material_id: str | None = ...
The identifier of the key material used to encrypt the data key.
class-attribute
instance-attribute
¶
Metadata about the response that produced this output. Use this to recover the request identifiers a service's support team needs in order to investigate a call. Members of the metadata are individually optional.