POST /#X-Amz-Target=TrentService.Encrypt

Encrypts plaintext of up to 4,096 bytes using a KMS key. You can use a symmetric or asymmetric KMS key with a KeyUsage of ENCRYPT_DECRYPT.

You can use this operation to encrypt small amounts of arbitrary data, such as a personal identifier or database password, or other sensitive information. You don't need to use the Encrypt operation to encrypt a data key. The GenerateDataKey and GenerateDataKeyPair operations return a plaintext data key and an encrypted copy of that data key.

If you use a symmetric encryption KMS key, you can use an encryption context to add additional security to your encryption operation. If you specify an EncryptionContext when encrypting data, you must specify the same encryption context (a case-sensitive exact match) when decrypting the data. Otherwise, the request to decrypt fails with an InvalidCiphertextException. For more information, see Encryption Context in the Key Management Service Developer Guide.

If you specify an asymmetric KMS key, you must also specify the encryption algorithm. The algorithm must be compatible with the KMS key spec.

When you use an asymmetric KMS key to encrypt or reencrypt data, be sure to record the KMS key and encryption algorithm that you choose. You will be required to provide the same KMS key and encryption algorithm when you decrypt the data. If the KMS key and algorithm do not match the values used to encrypt the data, the decrypt operation fails.

You are not required to supply the key ID and encryption algorithm when you decrypt with symmetric encryption KMS keys because KMS stores this information in the ciphertext blob. KMS cannot store metadata in ciphertext generated with asymmetric keys. The standard format for asymmetric key ciphertext does not include configurable fields.

The maximum size of the data that you can encrypt varies with the type of KMS key and the encryption algorithm that you choose.

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:Encrypt (key policy)

Related operations:

Servers

Request headers

Name Type Required Description
X-Amz-Content-Sha256 String No
X-Amz-Credential String No
X-Amz-Target String Yes

Valid values:

  • "TrentService.Encrypt"
Content-Type String Yes The media type of the request body.

Default value: "application/json"

X-Amz-Date String No
X-Amz-Algorithm String No
X-Amz-SignedHeaders String No
X-Amz-Security-Token String No
X-Amz-Signature String No

Request body fields

Name Type Required Description
GrantTokens[] Array No

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.

Plaintext String Yes

Data to be encrypted.

EncryptionAlgorithm String No

Specifies the encryption algorithm that KMS will use to encrypt the plaintext message. The algorithm must be compatible with the KMS key that you specify.

This parameter is required only for asymmetric KMS keys. The default value, SYMMETRIC_DEFAULT, is the algorithm used for symmetric encryption KMS keys. If you are using an asymmetric KMS key, we recommend RSAES_OAEP_SHA_256.

The SM2PKE algorithm is only available in China Regions.

Valid values:

  • "SYMMETRIC_DEFAULT"
  • "RSAES_OAEP_SHA_256"
  • "SM2PKE"
  • "RSAES_OAEP_SHA_1"
KeyId String Yes

Identifies the KMS key to use in the encryption operation. The KMS key must have a KeyUsage of ENCRYPT_DECRYPT. To find the KeyUsage of a 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.

How to start integrating

  1. Add HTTP Task to your workflow definition.
  2. Search for the API you want to integrate with and click on the name.
    • This loads the API reference documentation and prepares the Http request settings.
  3. Click Test request to test run your request to the API and see the API's response.