[ aws . kms ]

generate-data-key-pair

Description

Generates a unique asymmetric data key pair. The GenerateDataKeyPair operation returns a plaintext public key, a plaintext private key, and a copy of the private key that is encrypted under the symmetric KMS key you specify. You can use the data key pair to perform asymmetric cryptography and implement digital signatures outside of KMS.

You can use the public key that GenerateDataKeyPair returns to encrypt data or verify a signature outside of KMS. Then, store the encrypted private key with the data. When you are ready to decrypt data or sign a message, you can use the Decrypt operation to decrypt the encrypted private key.

To generate a data key pair, you must specify a symmetric KMS key to encrypt the private key in a data key pair. You cannot use 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.

Use the KeyPairSpec parameter to choose an RSA or Elliptic Curve (ECC) data key pair. KMS recommends that your use ECC key pairs for signing, and use RSA key pairs for either encryption or signing, but not both. However, KMS cannot enforce any restrictions on the use of data key pairs outside of KMS.

If you are using the data key pair to encrypt data, or for any operation where you don’t immediately need a private key, consider using the GenerateDataKeyPairWithoutPlaintext operation. GenerateDataKeyPairWithoutPlaintext returns a plaintext public key and an encrypted private key, but omits the plaintext private key that you need only to decrypt ciphertext or sign a message. Later, when you need to decrypt the data or sign a message, use the Decrypt operation to decrypt the encrypted private key in the data key pair.

GenerateDataKeyPair returns a unique data key pair for each request. The bytes in the keys are not related to the caller or the KMS key that is used to encrypt the private key. The public key is a DER-encoded X.509 SubjectPublicKeyInfo, as specified in RFC 5280 . The private key is a DER-encoded PKCS8 PrivateKeyInfo, as specified in RFC 5958 .

You can use the 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 state: Effect on your KMS key 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:GenerateDataKeyPair (key policy)

Related operations:

• Decrypt

• Encrypt

• GenerateDataKey

• GenerateDataKeyPairWithoutPlaintext

• GenerateDataKeyWithoutPlaintext

See also: AWS API Documentation

See ‘aws help’ for descriptions of global parameters.

Synopsis

  generate-data-key-pair
[--encryption-context <value>]
--key-id <value>
--key-pair-spec <value>
[--grant-tokens <value>]
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]

Options

--encryption-context (map)

Specifies the encryption context that will be used when encrypting the private key in the data key pair.

An encryption context is a collection of non-secret key-value pairs that represents 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 optional when encrypting with a symmetric KMS key, but it is highly recommended.

For more information, see Encryption Context in the Key Management Service Developer Guide .

key -> (string)

value -> (string)

Shorthand Syntax:

KeyName1=string,KeyName2=string

JSON Syntax:

{"string": "string"
  ...}

--key-id (string)

Specifies the symmetric KMS key that encrypts the private key in the data key pair. 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 .

--key-pair-spec (string)

Determines the type of data key pair that is generated.

The KMS rule that restricts the use of asymmetric RSA KMS keys to encrypt and decrypt or to sign and verify (but not both), and the rule that permits you to use ECC KMS keys only to sign and verify, are not effective on data key pairs, which are used outside of KMS.

Possible values:

• RSA_2048

• RSA_3072

• RSA_4096

• ECC_NIST_P256

• ECC_NIST_P384

• ECC_NIST_P521

• ECC_SECG_P256K1

--grant-tokens (list)

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 .

(string)

Syntax:

"string" "string" ...

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with --cli-input-yaml.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

See ‘aws help’ for descriptions of global parameters.

Output

PrivateKeyCiphertextBlob -> (blob)

The encrypted copy of the private key. When you use the HTTP API or the Amazon Web Services CLI, the value is Base64-encoded. Otherwise, it is not Base64-encoded.

PrivateKeyPlaintext -> (blob)

The plaintext copy of the private key. When you use the HTTP API or the Amazon Web Services CLI, the value is Base64-encoded. Otherwise, it is not Base64-encoded.

PublicKey -> (blob)

The public key (in plaintext).

KeyId -> (string)

The Amazon Resource Name (key ARN ) of the KMS key that encrypted the private key.

KeyPairSpec -> (string)

The type of data key pair that was generated.